Acta Microbiologica Hellenica doi: 10.3390/amh71020013

Authors: Araya Khaimook Kittiphan Chienwichai Arunchai Chang

Background: The clinical significance of Helicobacter pylori (H. pylori) infection in acute non-variceal upper gastrointestinal bleeding (NVUGIB) remains uncertain, particularly regarding short-term outcomes beyond rebleeding. Methods: We conducted a single-center retrospective cohort study of consecutive adults admitted with acute NVUGIB to Hatyai Hospital, Thailand, between January 2016 and December 2020. H. pylori status was determined during the index hospitalization using rapid urease testing and/or histopathologic examination of gastric biopsy specimens obtained during upper gastrointestinal endoscopy. The primary outcome was 30-day all-cause mortality. Secondary outcomes included in-hospital mortality, rebleeding, requirement of packed red blood cell transfusion, and length of hospital stay. Multivariable regression analyses were performed to adjust for potential confounders. Results: Among 933 patients, 289 (31.0%) were H. pylori-positive and 644 (69.0%) were H. pylori-negative. The H. pylori-positive group was younger, predominantly male, and had lower rates of cirrhosis and prior proton pump inhibitor use. They also more often had peptic ulcer bleeding and underwent earlier endoscopy. H. pylori positivity was independently associated with lower 30-day mortality (adjusted odds ratio 0.39, 95% confidence interval 0.18–0.84), but not with rebleeding, requirement of transfusion, or length of stay. Conclusions: H. pylori positivity was associated with lower short-term mortality in acute NVUGIB, although this finding may reflect baseline clinical differences rather than a direct effect on bleeding severity.

Acta Microbiologica Hellenica doi: 10.3390/amh71020012

Authors: Laneshia Conner Lirisha Tuladhar

Background: The vagina undergoes important changes across the life course that are shaped not only by hormonal transitions but also by shifts in the vaginal microbial environment. Despite growing interest in the vaginal microbiome, research has disproportionately centered reproductive-aged populations, leaving the aging vagina comparatively understudied. Objective: This article examines the aging vagina through a life-course lens, with emphasis on microbial and clinical transitions associated with midlife and older adulthood. Key Content: The article highlights menopause-related changes and approaches for reducing stigma and missed clinical opportunities. Particular attention is given to menopause-related declines in estrogen, reduced glycogen availability, increased vaginal pH, and accompanying changes in microbial balance, as well as their relationship to dryness, irritation, genitourinary symptoms, and susceptibility to adverse outcomes. The article also provides health professionals with a practical educational framework for symptom recognition, patient communication, vaginal health assessment, menopause-related education, stigma reduction, and prevention of missed clinical opportunities. Conclusions: Positioning the aging vagina within life-course and microbial-health frameworks can strengthen prevention, improve symptom recognition, and support more age-inclusive, informed, and responsive care for older women.

Acta Microbiologica Hellenica doi: 10.3390/amh71020011

Authors: Mohammad Jamal Abdulnaser Bitar Anhar Alhebshi Abdullah Ibrahim Alsafran Izz Eddin Majed Alchikhsuliman Rawnaq Osama Abdulghaffar Alzoubi Ahmed Alhabashi Idris Sula Mateq Ali Alreshidi

Introduction: In recent years, antibiotic resistance has increased a lot due to inappropriate prescribing practices, presenting a critical global health challenge. There is evidence of inappropriate prescription practices by dental practitioners in Saudi Arabia. Aim: This scoping review of the published literature aimed to report on the knowledge levels and practice of antibiotic prescriptions among dental practitioners in Saudi Arabia. Methods: Three databases (PubMed, ProQuest and Scopus) were searched for relevant studies; eligible studies (primary research conducted in Saudi Arabia) were organized into three broad domains: knowledge among dental students, knowledge levels among dentists, and prescribing practice among dentists. The quality of the included studies was assessed with the Newcastle–Ottawa Scale. Results: Of the 407 search records, 22 were eligible for inclusion. Almost all studies (n = 21) were cross-sectional in design. Most of the included studies assessed the knowledge among dental students, interns and practicing dentists. Two studies were analyzing medical records and antibiotic prescribing patterns, whereas only one study was implemented as a clinical audit whose measures resulted in positive outcomes (i.e., decrease in prescriptions and increase in awareness). Most of the studies revealed a low level of knowledge and inappropriate prescription patterns among dental students and interns. Conclusions: Since only one study evaluated an interventional approach (clinical audit) that resulted in a significant reduction in inappropriate prescriptions, future research should focus on measurements and interventions to increase awareness and reduce inappropriate prescriptions.

Acta Microbiologica Hellenica doi: 10.3390/amh71020010

Authors: Defkalion Karakalpakis Sofia Kanatsou Zoe Siateli Kalliopi Pappa Panagiotis Antsaklis Anastasia Barbouni Louis Gros Ekaterina Charvalos

Early-onset infection caused by Streptococcus agalactiae (Group B Streptococcus, GBS) may occur during gestation or delivery and can lead to severe neonatal sepsis, meningitis, or pneumonia. Discordant GBS infections in twin gestations are rare. We report a fatal case of early-onset GBS infection in dichorionic–diamniotic twins conceived via IVF and delivered by caesarean section at 32 weeks’ gestation due to discordant fetal growth and abnormal Doppler indices in Twin A (Umbilical Artery PI = 1.4; Middle Cerebral Artery PI = 1.5). Twin A had Apgar scores of 3, 5, and 5 and rapidly developed tachycardia, respiratory distress, and systemic infection, while Twin B, with Apgar scores of 7, 8, and 9, remained clinically stable. Both infants were admitted to the NICU and underwent routine blood, urine, and cerebrospinal fluid testing. Despite the prompt initiation of parenteral ceftriaxone and respiratory support, Twin A deteriorated rapidly and died within 28 h. GBS was isolated from Twin A’s blood culture, and maternal placental tissue and high vaginal samples collected before antibiotic administration also grew GBS, with all isolates demonstrating identical antimicrobial resistance profiles. Molecular analysis revealed matching rib1 and alp2/3 gene patterns in isolates from the mother and Twin A. Maternal anovaginal immunochromatography at delivery was positive, whereas screening cultures obtained at 29 weeks’ gestation were negative. This case highlights the limitations of culture-based GBS screening in high-risk pregnancies and preterm deliveries and underscores the potential value of molecular assays and point-of-care testing to improve detection of S. agalactiae throughout pregnancy and the peripartum period. Emerging preventive strategies, including modulation of the genital microbiome and maternal vaccination aligned with WHO recommendations, may further reduce the burden of neonatal GBS disease.

Acta Microbiologica Hellenica doi: 10.3390/amh71020009

Authors: Maria Ntouska Nikos Anthis Claudia Lakoniti Konstantina Nestora Aggeliki Paschali Panteleimon Vakianis Christos Drakos Aikaterini Kapadocha Panagiota Aggeli Ourania Tsakalidou Dimitrios Chatzidimitriou Georgios Dougas Anna Papa

Leptospirosis is a zoonotic disease caused by spirochetes of the genus Leptospira, primarily transmitted via direct or indirect contact with contaminated rodent urine. Human disease ranges from a mild, flu-like illness to severe, life-threatening Weil’s disease. Although the incidence of leptospirosis in Greece is not high, the Ionian Islands Region, including Corfu Island, presents the highest average frequency of cases in the country. A retrospective study of 11 confirmed cases in Corfu between 2015 and 2025 was conducted. The infections recorded during this period occurred from autumn to spring, exclusively affecting male patients in rural settings; notably, 90.9% of cases were attributed to occupational exposure. No association with urban or tourist areas was found. Although the incidence of the disease decreased by 42.1% compared to the previous decade (2005–2014), the case fatality ratio reached 27.3%, considerably above the average of 2.6% in Europe (during 2010–2022). The study underscores the need for enhanced clinical awareness and targeted preventive measures in Corfu, mainly among patients with at-risk occupations. Timely preparedness is needed especially in the face of ongoing climate change.

Acta Microbiologica Hellenica doi: 10.3390/amh71010008

Authors: Alessia Mirabile Dalida Bivona Giuseppe Nicolò Conti Andrea Marino Benedetto Maurizio Celesia Grazia Scuderi Paolo Fagone Serena Matera Serena Spampinato Giuseppe Nunnari

People living with HIV (PLWH) receiving effective antiretroviral therapy (ART) continue to exhibit chronic immune activation and systemic inflammation despite virological suppression. The viral envelope glycoprotein gp120, which binds the CD4 receptor and mediates viral entry, has been implicated in pro-inflammatory and pro-apoptotic effects in neuronal and endothelial cells. Although gp120 is expressed on the viral surface, its oligomeric structure and its ability to form immune complexes with circulating antibodies may reduce the sensitivity of standard detection assays in serum. Soluble gp120 has been associated with increased levels of pro-inflammatory cytokines, including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β), as well as chemokines. These mediators may contribute to blood–brain barrier dysfunction, endothelial injury, vascular smooth muscle alterations, and subsequent neurodegenerative and cardiovascular complications. Importantly, gp120 shedding may persist due to viral reservoirs and intermittent reactivation, even during ART. Fostemsavir inhibits the interaction between gp120 and CD4, preventing viral entry and potentially limiting gp120-mediated pathogenic effects. Beyond antiviral activity, this mechanism suggests a potential role in attenuating gp120-mediated inflammation. This review discusses the biological effects of gp120 and the rationale for targeting it therapeutically in PLWH.

Acta Microbiologica Hellenica doi: 10.3390/amh71010007

Authors: Luís Furtado

Clostridioides difficile infection (CDI) remains a major cause of healthcare-associated morbidity and mortality, particularly among older adults and patients with recent healthcare exposure, underscoring the need for early risk stratification and accurate prognostic assessment. This retrospective observational study evaluated clinical, laboratory, and therapeutic factors associated with disease severity and in-hospital mortality, and assessed the predictive performance of the ATLAS score and the Charlson comorbidity index. A total of 101 adult inpatients with laboratory-confirmed CDI admitted to a Portuguese tertiary care hospital were included. Data were extracted from clinical records and analysed using comparative statistics, multivariable logistic regression, and Kaplan–Meier survival analysis. Advanced age, elevated white blood cell count, renal dysfunction, and prior exposure to multiple antibiotic classes were independently associated with increased disease severity and mortality. The ATLAS score demonstrated good discriminative ability, particularly for short-term mortality, and showed higher sensitivity compared with the Charlson comorbidity index. These findings provide additional evidence on clinical and laboratory factors associated with severe CDI and in-hospital mortality, while supporting the utility of the ATLAS score as a practical tool for early risk stratification in hospitalised patients.

Acta Microbiologica Hellenica doi: 10.3390/amh71010006

Authors: Adriana Barros Luna Gomes Eloia Emanuelly Dias Silva Pedro Henrique Macedo Moura Deise Maria Rego Rodrigues Silva Marina dos Santos Barreto Ronaldy Santana Santos Luana Ramony da Silva Lisboa André Gustavo Carvalho de Oliveira Adriana Kelly Santana Corrêa Pedro Guilherme Menezes dos Santos Laylla Maria de Freitas Lima Adriana Gibara Guimarães Lucas Alves da Mota Santana Kumaraswamy Athesh Rajiv Gandhi Gopalsamy Gianpaolo Roina Susana de Souza Lalic Lysandro Pinto Borges

The COVID-19 pandemic necessitated rigorous infection control protocols across hospital environments, particularly in nutrition services. UV-C light emerged as a viable option due to its shortest wavelength, conferring the greatest capacity for nucleic acid (DNA/RNA) penetration in both microorganisms and human cells. We aim to develop and validate an alternative method for decontaminating food carts using UV-C light. A prototype box was created to cover the meal transport carts, with UV-C lamps strategically positioned for irradiation and decontamination. To validate this technology, four different hygiene protocols were compared: Group 1, positive control, with no sanitization procedure; Group 2, cleaned using the standard protocol of the University Hospital of UFS (HU/UFS) with 70% ethanol solution; Group 3, negative control, cleaned using the standard HU/UFS protocol with 70% ethanol and neutral detergent; and Group 4, exposed to UV-C light irradiation for 10 min after food transport. Microbiological samples were collected from 15 distinct points on the carts. Samples were collected using sterile swabs moistened with 0.85% saline solution and incubated in BHI broth at 37 °C for 24 h for presence/absence testing. Positive samples were plated on selective media (CLED, SS, MacConkey and Blood agar), incubated at 37 °C for 24–48 h, and evaluated for colony-forming unit (CFU) count. A statistically significant association was found between the hygiene method and the presence of microbial contamination (p < 0.001), based on both bacterial plate counts and BHI broth growth. Carts sanitized with 70% alcohol showed a lower probability of contamination compared to the control group (alcohol + detergent), while unsanitized carts showed a higher risk. UV-C light treatment resulted in complete absence of bacterial growth. UV-C disinfection demonstrated superior effectiveness in eliminating microorganisms, indicating a promising alternative to traditional methods.

Acta Microbiologica Hellenica doi: 10.3390/amh71010005

Authors: Stefanos Charpantidis Natalia Zacharopoulou Ioannis Daniil Sofia Xydia Aggeliki Mpouskou Kalliopi Theodoridou Georgia Vrioni Chrysoula Verra

Chlamydia is the most common sexually transmitted infection (STI) worldwide. In 2020, the global prevalence was estimated to be 4.0% among women and 2.5% among men aged 15 to 49 years. In more than 80% of cases, the infection is asymptomatic, thereby increasing the risk of subsequent infections. Complications in women can include chronic pain, pelvic inflammatory disease, and an increased risk of ectopic pregnancies. Chlamydia trachomatis (CT) infections can be diagnosed using several techniques, including cell culture, immunofluorescence, enzyme immunoassays, and polymerase chain reaction (PCR). PCR is regarded as the gold standard for screening and detection of CT. We conducted a three-year retrospective study from January 2022 to December 2024, collecting 4241 cervicovaginal swab samples from outpatient gynecology patients. The overall prevalence of CT in our study was 2.02%. An increase in CT detection during the study period was observed: from 24 cases (1.7%) in 2022 to 30 cases (2%; p = 0.64) in 2023 and 32 cases (2.35%; p = 0.26) in 2024. The highest proportion of cases was observed in the 20–24 and 25–34 age groups. Notably, 7 out of 10 cases were asymptomatic. Risk factors for chlamydial infections include behavioral factors, such as having multiple sexual partners and engaging in risky sexual practices, as well as social and lifestyle influences.

Acta Microbiologica Hellenica doi: 10.3390/amh71010004

Authors: Evangelia Giosi Ifigenia Dimopoulou Enada Leshi Maria Christoforidi Andigoni Malousi Theano Georgakopoulou Christos Hadjichristodoulou Dimitris Hatzigeorgiou Stella Vorre Dimitris Paraskevis Cleo Anastassopoulou Maria Exindari Georgia Gioula

Parvovirus B19 is a DNA virus. Most parvoviruses infect animals; Parvovirus B19 infects humans. Parvovirus B19 is mainly transmitted through respiratory droplets during close contact, but additional routes such as transmission through contaminated blood products and vertical transmission from mother to fetus have also been documented. Infections occur throughout the year, with a seasonal increase between late winter and early summer. Clinical symptoms depend on age, and on patients’ immune status. Healthy, immunocompetent individuals experience asymptomatic or mild infections including a febrile rash; serious complications rarely appear, such as rheumatoid-like arthritis or acute myocarditis. Clusters of myocarditis cases following Parvovirus B19 infections appeared in a daycare in Thessaloniki in 2024. To molecularly and phylogenetically characterize Parvovirus B19 strains detected during a pediatric outbreak associated with elevated troponin levels and myocarditis in Northern Greece, and to compare these strains with isolates from adult cases with mild symptoms in order to explore potential associations between viral genetic variability and cardiac involvement. MinION sequencing protocol was performed for nine whole blood samples, seven belonging to children with myocarditis, and two to adults presenting mild symptoms. Statistical analysis was performed with QualiMap 2.3 and relevant tools. Phylogenetic analysis identified distinct viral groups originating from the samples investigated. A distinct branch was formed by the reference genome and the ones of the adults’ samples, while samples from children with myocarditis provided discrete branches differing from the reference one. The findings demonstrate a clear association between Parvovirus B19 infection and myocarditis in the pediatric cases analyzed. The detected viral strains, including variants identified in several samples, support the role of Parvovirus B19 as a contributing factor in post-infectious cardiac involvement. Although these results reinforce the clinical relevance of Parvovirus B19 in childhood myocarditis, expanding the sample size would allow for a more robust characterization of circulating strains and confirmation of the observed patterns.

Acta Microbiologica Hellenica doi: 10.3390/amh71010003

Authors: Prodromos Sakaloglou Petros Bozidis Konstadina Kourou Charilaos Kostoulas Athanasia Gouni Eleni Tsaousi Despoina Koumpouli Sofia Argyropoulou Petros Oikonomidis Helen Peponi Ioannis Sarantaenas Eirini Christaki Ioannis Georgiou Konstantina Gartzonika

The Institutional Review Board Statement and Informed Consent Statement sections in the original publication [...]

Acta Microbiologica Hellenica doi: 10.3390/amh71010002

Authors: Ángel Fabiola Murillo-Rojas Rodney Agustín Ng-Araya Stefany Lozada-Alvarado Daniela Jaikel-Víquez Allan Ignacio Valverde-Vindas

Genitourinary infections caused by Candida spp. and other yeasts have increased in incidence, and the emergence of resistant isolates to commonly prescribed antifungals is becoming more frequent. Thus, the purpose of this study was to characterize the physiological characteristics of 38 yeast isolates (Candida albicans [n = 32], Candida tropicalis [n = 3], and Nakaseomyces glabratus [n = 3]) recovered from genitourinary infections to better understand the diversity of their physiological profiles, their virulence factors, and their role in pathogenicity. In addition, an experimental study was conducted to determine the minimum inhibitory concentration (MIC) of the isolates using the M27-A3 microdilution method described by the Clinical Laboratory and Standards Institute. Clinical isolates of Candida spp. studied showed in vitro susceptibility to both fluconazole and clotrimazole, the latter having greater antifungal activity due to its lower MIC50. Statistically significant differences were found between the MICs obtained for fluconazole and clotrimazole, with the latter showing the highest in vitro activity. Therefore, the clinical use of clotrimazole is recommended, as is the ongoing need for this type of analysis to monitor changes in susceptibility profiles over time.

Acta Microbiologica Hellenica doi: 10.3390/amh71010001

Authors: Nikolaos P. Tzavellas Natalia Atzemoglou Petros Bozidis Konstantina Gartzonika

The emergence and dissemination of antimicrobial resistance (AMR) are driven by complex, interconnected mechanisms involving microbial communities, environmental factors, and human activities, with climate change playing a pivotal and accelerating role. Rising temperatures, altered precipitation patterns, and other environmental disruptions caused by climate change create favorable conditions for bacterial growth and enhance the horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs). Thermal stress and environmental pressures induce genetic mutations that promote resistance, while ecosystem disturbances facilitate the stabilization and spread of resistant pathogens. Moreover, climate change exacerbates public and animal health risks by expanding the range of infectious disease vectors and driving population displacement due to extreme weather events, further amplifying the transmission and evolution of resistant microbes. Livestock agriculture represents a critical nexus where excessive antibiotic use, environmental stressors, and climate-related challenges converge, fueling AMR escalation with profound public health and economic consequences. Environmental reservoirs, including soil and water sources, accumulate ARGs from agricultural runoff, wastewater, and pollution, enabling resistance spread. This review aims to demonstrate how the Mediterranean’s strategic position makes it an ideal living laboratory for the development of integrated “One Health” frameworks that address the mechanistic links between climate change and AMR. By highlighting these interconnections, the review underscores the need for a unified approach that incorporates sustainable agricultural practices, climate mitigation and adaptation within healthcare systems, and enhanced surveillance of zoonotic and resistant pathogens—ultimately offering a roadmap for tackling this multifaceted global health crisis.

Acta Microbiologica Hellenica doi: 10.3390/amh70040047

Authors: Kapka Mancheva Georgi Atanasov

The European catfish (Silurus glanis, Linnaeus 1758), commonly known as the wels catfish, is one of the largest freshwater fish in Europe and an ecologically and economically important species in both natural ecosystems and aquaculture. Its broad native distribution, together with the rapid growth of farming practices, increases concerns about pathogen dissemination and their potential impact on biodiversity, animal health, and potential risks to human healthcare. This review is based on a structured literature search following PRISMA recommendations for narrative reviews and summarizes current knowledge on the main pathogen groups affecting S. glanis—viruses (ranaviruses, alloherpesviruses), bacteria (Aeromonas spp., Edwardsiella spp.), protozoan and metazoan parasites (Ichthyophthirius multifiliis, Thaparocleidus spp., Eustrongylides spp., Contracaecum larvae), and oomycetes (Saprolegnia spp., Branchiomyces spp.). Within the One Health approach, particular attention is given to zoonotic pathogens such as Aeromonas spp., Edwardsiella tarda, and helminths like Eustrongylides and Contracaecum, which may cause risks to human health through contaminated water or consumption of raw or undercooked fish. The review integrates findings from field surveys, regional case studies such as those from the Danube basin, and data from the authors’ doctoral research. Because the wels catfish is increasingly cultivated and serves as an apex predator in natural habitats, its effective disease management is critical for both aquaculture and wild populations, and also for the food chains at all. Strengthened surveillance, health monitoring, and biosecurity measures are essential preventing the introduction and spread of pathogens into new hosts and habitats. Through the underlining of major catfish pathogen groups, this review highlights key challenges within the One Health approach and underscores the need for integrated health monitoring, biosecurity, and environmental management strategies.

Acta Microbiologica Hellenica doi: 10.3390/amh70040046

Authors: Laura Trovato Maddalena Calvo Andrea Marino Pasqua Maria Lucia Betta Carmine Loretta Mattia Guido Scalia

Malassezia spp. has been recognized among neonatal intensive care unit (NICU) patients’ commensals and pathogens, accounting for a significant number of invasive fungal infections. The Random Amplified Polymorphic DNA (RAPD) may be used for Malassezia spp. strains typing from clinical isolates, demonstrating high resolution and specificity. Herein, we propose a retrospective analysis of Malassezia spp. isolates, aiming to investigate their identity and transmission pathways. Moreover, we documented Malassezia spp. prevalence within the University Hospital Policlinico of Catania, Italy. The analysis collected a total number of 16 M. pachydermatis and categorized them into four different clusters, hypothesizing a horizontal transmission. Although the essential role of microbiological sample cultures, our data suggested further environmental surveillance protocols to prevent NICU patients’ colonization due to the Malassezia spp. persistence and adhesion within healthcare surfaces.

Acta Microbiologica Hellenica doi: 10.3390/amh70040045

Authors: Meiji Soe Aung Noriko Urushibara Mitsuyo Kawaguchiya Nobuhide Ohashi Thida San Win Kalayar Kyaw Mina Hirose Masako Osada Masahiko Ito Nobumichi Kobayashi

Linezolid (LZD) is an oxazolidinone antibiotic effective in the treatment of infection with Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). The decline in susceptibility to linezolid is a concern for antimicrobial chemotherapy. In this study, the prevalence of the LZD minimum inhibitory concentration (MIC) of 2 mg/L (LZD-MIC2), which represents a slightly high value within a range of susceptibility for S. aureus (≤4 mg/L), was investigated retrospectively for staphylococcal species from different sources. We collected the records of LZD MIC of Staphylococcus/Mammaliicoccus that had been obtained in our previous studies on isolates from patients, healthy individuals, and foodstuff. Prevalence of isolates showing LZD-MIC2 was analyzed depending on the type of staphylococcal species and S. aureus clones. In clinical isolates, methicillin-susceptible S. aureus (MSSA) and S. argenteus showed significantly higher LZD-MIC2 rates (20.0% and 21.5%, respectively) than MRSA (7.3%). Among clinical and colonizing isolates of MSSA, LZD-MIC2 was more commonly found in CC1 (ST188, ST2990, etc.), CC8, CC15, ST30, ST97, and ST121 than other lineages. In S. argenteus isolates, which were mostly methicillin-susceptible, there was no significant difference in the LZD-MIC2 prevalence among the three genotypes. The LZD-MIC2 was detected in 18.3% of coagulase-negative staphylococci (CoNS), with S. saprophyticus, S. pasteuri, and M. sciuri showing higher prevalence (30–57%) than other species. The present study revealed that the prevalence of the LZD-MIC2 is different depending on staphylococcal species/types, as they are more common in specific MSSA lineages and some CoNS species.

Acta Microbiologica Hellenica doi: 10.3390/amh70040044

Authors: Andrea Marino Ermanno Vitale Antonino Maniaci Luigi La Via Vittoria Moscatt Serena Spampinato Paola Senia Emmanuele Venanzi Rullo Vincenzo Restivo Bruno Cacopardo Giuseppe Nunnari

West Nile Virus (WNV), a mosquito-borne flavivirus first identified in Uganda in 1937, has emerged over the past quarter century as a major global public health threat. Since its introduction into North America in 1999, WNV has become the leading cause of arboviral neuroinvasive disease, with recurrent outbreaks continuing across Europe, Africa, and the Americas. This review provides a comprehensive overview of the microbiology, epidemiology, and clinical impact of WNV. We discuss the molecular biology of the virus, highlighting its genomic organization, replication strategies, and the structural and non-structural proteins that underpin viral pathogenesis and immune evasion. The complex enzootic transmission cycle, involving Culex mosquitoes and diverse avian reservoir hosts, is examined alongside ecological and climatic determinants of viral amplification and spillover into humans and equines. The clinical spectrum of WNV infection is outlined, ranging from asymptomatic seroconversion to West Nile fever and life-threatening neuroinvasive disease, with particular emphasis on risk factors for severe outcomes in older and immunocompromised individuals. Current approaches to diagnosis, supportive management, and vector control are critically reviewed, while challenges in vaccine development and the absence of effective antiviral therapy are underscored. Finally, we address future research priorities, including therapeutic innovation, predictive outbreak modeling, and genomic surveillance of viral evolution. WNV exemplifies the dynamics of emerging zoonotic diseases, and its persistence underscores the necessity of a coordinated One Health approach integrating human, animal, and environmental health. Continued scientific advances and public health commitment remain essential to mitigate its enduring global impact.

Acta Microbiologica Hellenica doi: 10.3390/amh70040043

Authors: Francesco Coletta Angela Sinagoga Martina Mariani Giuseppe Napolitano Pasquale Rinaldi Alessandro Perrella Francesca Schettino Crescenzo Sala Tiziana Ascione Ilaria Mataro Carlo Petroccione Maria Rosaria Cavezza Antonio Tomasello Raffaele Annunziata Romolo Villani

Severely burned patients are at high risk of local and systemic infections due to skin barrier loss. Their clinical management is complex and requires coordinated intensive care and infection prevention strategies. Diagnosing infective endocarditis (IE) in this population is particularly difficult due to overlapping symptoms and limited diagnostic specificity. Common pathogens include Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii. We conducted a retrospective cohort study on 543 patients with burns affecting >18% of total body surface area (TBSA), admitted to our Burn Intensive Care Unit (BICU) from 2019 to 2024. The incidence of infective endocarditis was 1.47%, involving aortic (75%), mitral (12.5%), and tricuspid (12.5%) valves. Pathogens identified included S. aureus, Klebsiella pneumoniae, A. baumannii, and P. aeruginosa. This incidence is significantly higher than that in the general population. Mortality reached 50%, with an overall 3-month mortality of 75%. The literature on IE in burn patients is scarce, and the role of antibiotic prophylaxis remains controversial. Infective endocarditis in burn patients, although rare, represents a severe complication with high mortality. Early diagnosis and coordinated multidisciplinary care are essential to improve patient outcomes.

Acta Microbiologica Hellenica doi: 10.3390/amh70040042

Authors: Alessia Catalano

The COVID-19 pandemic resulted in high morbidity and mortality, as well as severe social and economic disruption globally. Since the pandemic began in 2019, the severe acute respiratory syndrome, coronavirus 2, has undergone numerous changes, resulting in the emergence of new variants and subvariants. The emergence of new variants of the virus poses a challenge to scientists. There is currently no SARS-CoV-2 variant meeting the criteria of variants of concern, whereas the only variant of interest is JN.1, and there are six variants under monitoring: LP8.1, NP1.8.1, XEC, KP.3, KP.3.1.1 and the latest, XFG (Stratus). Although the latter appears to be more transmissible than the others, genomic evidence indicates that it is less aggressive than some recent variants. Nevertheless, continuous genomic surveillance of COVID-19 is still important to detect any new variants that could threaten public health. Numerous therapeutic strategies, such as drugs, vaccines, and nutritional supplements, are being used to treat COVID-19. This narrative review is an overview of COVID-19 and its various facets, from the number of cases to the therapies used, the current variants, and the ongoing clinical trials, specifically focusing on the most recent studies.

Acta Microbiologica Hellenica doi: 10.3390/amh70040041

Authors: Muharrem Okan Cakir Melis Selek Betul Yilmaz Mustafa Ozdogan Gholam Hossein Ashrafi

Genome editing technologies, including CRISPR/Cas9, TALENs, and ZFNs, offer promising approaches to disrupt HPV oncogenes E6 and E7, thereby restoring tumor-suppressor pathways. In this review, we summarize recent preclinical findings demonstrating selective apoptosis and tumor regression in HPV-positive cell and animal models, as well as early-phase clinical studies exploring local CRISPR-based therapies. We also compare the relative strengths and limitations of major editing platforms, discuss delivery strategies, and highlight their potential integration with immunotherapy and conventional treatments. While preclinical studies show encouraging efficacy (e.g., up to 60% tumor regression in xenograft models and marked reactivation of p53/pRb pathways), translation into routine practice remains limited by challenges such as efficient delivery, minimizing off-target effects, long-term safety, cost, and ethical considerations. Continued optimization of high-fidelity nucleases, tissue-specific delivery systems, and genotype-tailored guide RNAs will be essential. Genome editing therefore represents a potential future addition to the therapeutic landscape of HPV-related diseases, but substantial barriers must be addressed before clinical implementation.

Acta Microbiologica Hellenica doi: 10.3390/amh70040040

Authors: Olamilekan Gabriel Banwo Olalekan Chris Akinsulie Ridwan Olamilekan Adesola Olalekan Taiwo Jeremiah

Dermatophilosis, caused by the Gram-positive, filamentous bacterium Dermatophilus congolensis, is an important skin disease that adversely affects cattle health and productivity. It also affects other domestic and wild animals and occasionally humans. This review provides a detailed overview of the molecular characteristics and resistome profile of D. congolensis, highlighting recent advances in genomic research. We examine the bacterium’s genome architecture, including its genome size, GC content, gene composition, and phylogenetic placement within the Actinomycetales. Key virulence factors are discussed, including proteolytic enzymes, hyphal invasion, zoospore motility, and the gene products of nasp and agac, emphasizing their roles in tissue invasion, pathogenesis, and diagnostic detection. Furthermore, we analyze resistome, focusing on identified antibiotic resistance genes, diverse resistance mechanisms such as efflux pumps and beta-lactamases, and the contribution of mobile genetic elements to horizontal gene transfer. The implications of these molecular insights for accurate diagnosis, effective treatment, and antibiotic stewardship in cattle production are critically evaluated. Finally, we highlight future research priorities aimed at deepening our understanding of D. congolensis biology and improving strategies for disease control. This review underscores the importance of integrating molecular surveillance with antimicrobial monitoring to safeguard cattle health and promote sustainable livestock management.

Acta Microbiologica Hellenica doi: 10.3390/amh70040039

Authors: Amit Patnaik Titirsha Kayal Soumya Basu

Worldwide, polymicrobial infections (PMIs) account for an estimated 20–50% of severe clinical infection cases, with biofilm-associated and device-related infections reaching 60–80% in hospitalized patients. This review discusses the clinical burden of major infections in which PMIs are almost inevitable, such as diabetic foot infections, intra-abdominal infections, pneumonia, and biofilm-associated device infections. Globally, the PMI landscape is diverse; however, the Indian subcontinent is a PMI hotspot where high comorbidities, endemic antimicrobial resistance, and underdeveloped diagnostic capacity elevate the risks of poor outcomes. Existing diagnostic like culture-based methods, PCR panels, sequencing, and biomarker-based assays are constrained by sensitivity, turnaround times (TATs), and high costs. Vulnerable populations, particularly neonates, the elderly, immunocompromised patients, and socioeconomically marginalized groups, show case-fatality rates 2-fold higher than monomicrobial infections in similar settings. Emerging diagnostic solutions include CRISPR-based multiplex assays, artificial intelligence-based metagenomic platforms, and sensitive biosensors with point-of-care applicability. These technologies show potential in reducing the TAT (<2 h) with high accuracy (>95%). However, their translation to real-world settings depends critically on affordability, integration into healthcare pathways, and supportive policy. This will provide equitable diagnostic access, particularly in low- and middle-income countries (LMICs).

Acta Microbiologica Hellenica doi: 10.3390/amh70040038

Authors: Amina Belboul Mohamed El Mohtadi Abdulmannan Fadel Jessica Mcloughlin Ayman Mahmoud Caitlin O’Malley Jason Ashworth

Age-related impaired wounds often become infected with bacteria, leading to substantial mortality and morbidity in the elderly. The decline in androgen levels with increasing age is believed to exacerbate inflammation during wound infections. Despite its well-documented anti-inflammatory activities in wound repair, little is known about the effect of age-related androgen deprivation on bacterial phagocytosis in impaired chronic wounds. The aim of this study was to investigate the effect of age-related testosterone deprivation on the phagocytic functions of THP-1 monocyte-derived macrophages to eliminate Gram-positive and Gram-negative bacteria in vitro. Host–pathogen interaction experiments were conducted to quantify the macrophage-mediated clearance of two common wound-associated bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, under in vitro environments that model testosterone levels representative of those found in elderly males, healthy young adults and testosterone replacement therapy (TRT). Testosterone and its metabolite 5α-dihydrotestosterone (DHT) significantly dampened the macrophage-mediated phagocytosis of both MRSA and P. aeruginosa in a dose-dependent manner (p < 0.05). Blockade of the androgen receptor (AR) using enzalutamide confirmed that testosterone mediates bacterial clearance through binding to the AR. Blocking the conversion of testosterone to DHT through stimulation of macrophages with the 5-α-reductase inhibitor finasteride reversed the testosterone-mediated effects on bacterial clearance, which confirmed that testosterone could potentially dampen the innate phagocytic responses in macrophages through conversion to DHT. Novel findings in this study suggest that the selective manipulation of the AR and/or blockade of testosterone–DHT conversion may provide effective therapeutic treatments to combat wound infections in the elderly.

Acta Microbiologica Hellenica doi: 10.3390/amh70030037

Authors: Melda Payaslioğlu Reyhan Başkiliç Esra Kazak Halis Akalin

Stenotrophomonas maltophilia is a nosocomial pathogen that is resistant to many broad-spectrum antibiotics. This study aimed to evaluate the in vitro synergy of trimethoprim/sulfamethoxazole (SXT) combined with levofloxacin (LEV) or ceftazidime (CAZ) using checkerboard and gradient diffusion methods. Between 2016 and 2021, 20 S. maltophilia strains (five SXT-resistant and 15 SXT-susceptible strains) were collected from various clinical settings. Their susceptibility to SXT, LEV, and CAZ was assessed using both checkerboard and gradient diffusion synergy tests. The gradient diffusion method was performed using commercial strip-based tests (Liofilchem®). It should be noted that the gradient diffusion method has not been standardized by the Clinical and Laboratory Standards Institute (CLSI) for synergy testing and is considered for research purposes only. In the checkerboard method, the SXT + LEV combination showed synergy in one strain and an additive effect in 19 strains; the SXT + CAZ combination exhibited synergy in eight strains and an additive effect in 12 strains. In the gradient diffusion method, the SXT + LEV combination showed synergy in one strain and an additive effect in 19 strains; the SXT + CAZ combination exhibited synergy in five strains, an additive effect in 14 strains, and antagonism in one strain. A correlation between the two methods was observed in 90% of SXT + LEV combinations and 65% of SXT + CAZ combinations. Both checkerboard and gradient diffusion methods yielded similar results, indicating their reliability in determining antibiotic combinations. Given the observed synergy, CAZ combinations may be effective for treating SXT-resistant strains.

Acta Microbiologica Hellenica doi: 10.3390/amh70030036

Authors: Enoch Chi Ngai Lim Chi Eung Danforn Lim

Microbiome-targeted therapies are redefining gastroenterology by delivering precision interventions that align with the body’s natural microbial ecosystem. This narrative review evaluates evidence for established approaches, probiotics, prebiotics, fecal microbiota transplantation (FMT), and postbiotics, and examines emerging innovations such as engineered probiotics, bacteriophage therapy, and metabolite-based interventions. Cure rates for recurrent Clostridium difficile infection in randomized trials range from 67% to 94%, depending on route and donor protocol, while multi-strain probiotics provide moderate benefits in inflammatory bowel disease. New modalities, including engineered bacteria and defined bacterial consortia, have progressed to Phase 3 trials, with several granted FDA breakthrough therapy designation. Approvals of Rebyota and Vowst mark a pivotal milestone, creating validated regulatory pathways for microbiome therapeutics. Despite progress, challenges remain in protocol standardisation, patient selection, cost-effectiveness, and clinical integration. Over 200 active trials and growing pharmaceutical investment signal a robust pipeline, with applications expanding to oncology, metabolic disorders, and immune modulation. Continued progress depends on validated biomarkers and personalized strategies guided by microbiome profiling. International regulatory harmonization will also be required to ensure safe and equitable adoption. The field is shifting toward working with, rather than against, the body’s microbial ecosystem, offering substantial potential for personalized gastrointestinal disease management.

Acta Microbiologica Hellenica doi: 10.3390/amh70030035

Authors: Nika Vlahović Vlašić Lada Zibar Petra Smajić Luka Švitek Domagoj Drenjančević

Background: Pancreatic stone protein (PSP) has emerged as a promising biomarker for the early diagnosis of sepsis, infectious diseases, and chronic inflammatory conditions, including cancer, diabetes, and inflammatory bowel disease. This review evaluates the role of PSP as a biomarker and functional protein, emphasizing its diagnostic and prognostic value. Methods: This review was conducted through a comprehensive literature search using the PubMed database, covering publications from the discovery of PSP in the 1980s up to 2025. The information was gathered into thematic sections to provide a comprehensive and structured review of PSP as a biomarker and functional protein in health and disease. Results: A total of 256 articles were reviewed and critically assessed, with 80 meeting the inclusion criteria and forming the basis of this review. The reviewed literature underscores PSP as a multifaceted protein involved in inflammation, immune modulation, tissue regeneration, and systemic infection. PSP shows promise as an early biomarker in critically ill patients. Conclusions: PSP is a clinically promising but not yet fully validated biomarker. To enable its routine clinical application, standardized diagnostic cutoffs, validation through multicenter trials, and integration with existing biomarker panels are required. Further research is warranted to fully establish its diagnostic and prognostic potential across diverse clinical settings.

Acta Microbiologica Hellenica doi: 10.3390/amh70030034

Authors: David Badenas-Alzugaray Alexander Tristancho-Baró Juan Manuel García-Lechuz Natalia Burillo-Navarrete Sara Sanz-Sanz Ana María Milagro-Beamonte Ana Isabel López-Calleja Antonio Rezusta-López

Aeromonas is a genus of Gram-negative, facultatively anaerobic bacteria commonly found in aquatic environments and increasingly recognized as opportunistic pathogens. Among them, Aeromonas dhakensis stands out for its high virulence and antimicrobial resistance, but it is often misidentified due to its phenotypic similarity with A. hydrophila and A. caviae. In this study, a microorganism was isolated from the peritoneal fluid of a patient with signs of intra-abdominal infection. MALDI-TOF MS initially suggested A. hydrophila or A. caviae, but the identification was confirmed with high confidence only after further molecular analyses and the use of genome-based tools, which identified the organism as A. dhakensis. This was further supported by phylogenomic and ANI analysis. Resistome analysis revealed intrinsic resistance genes, including a chromosomal class C β-lactamase and an imiH-type carbapenemase, consistent with the observed carbapenem resistance. No plasmid-mediated carbapenemases were found. These findings underscore the limitations of MALDI-TOF in identifying Aeromonas species in certain cases and highlight the value of genomic approaches for accurate species determination and resistance profiling, especially for isolates from sterile body fluids.

Acta Microbiologica Hellenica doi: 10.3390/amh70030033

Authors: Sara Occhipinti Carla Ettore Giosuè Giordano Incognito Chiara Gullotta Dalila Incognito Roberta Foti Giuseppe Nunnari Giuseppe Ettore

Sexually transmitted infections (STIs) are a significant global health concern, affecting millions of people worldwide, particularly sexually active adolescents and young adults. These infections, caused by various pathogens, including bacteria, viruses, parasites, and fungi, can have profound implications for women’s reproductive health and fertility. This review explores the role of vaginal and uterine infections in women’s infertility, focusing on the most common pathogens and their impact on reproductive outcomes. Bacterial infections, such as those caused by intracellular bacteria (Mycoplasma, Ureaplasma, and Chlamydia), Neisseria gonorrhoeae, and bacterial vaginosis, are among the most prevalent causes of infertility in women. Studies have shown that these infections can lead to pelvic inflammatory disease, tubal occlusion, and endometrial damage, all of which can impair fertility. Mycobacterium tuberculosis, in particular, is a significant cause of genital tuberculosis and infertility in high-incidence countries. Viral infections, such as Human papillomavirus (HPV) and Herpes simplex virus (HSV), can also affect women’s fertility. While the exact role of HPV in female infertility remains unclear, studies suggest that it may increase the risk of endometrial implantation issues and miscarriage. HSV may be associated with unexplained infertility. Parasitic infections, such as trichomoniasis and schistosomiasis, can directly impact the female reproductive system, leading to infertility, ectopic pregnancy, and other complications. Fungal infections, such as candidiasis, are common but rarely have serious outcomes related to fertility. The vaginal microbiome plays a crucial role in maintaining reproductive health, and alterations in the microbial balance can increase susceptibility to STIs and infertility. Probiotics have been proposed as a potential therapeutic strategy to restore the vaginal ecosystem and improve fertility outcomes, although further research is needed to establish their efficacy. In conclusion, vaginal and uterine infections contribute significantly to women’s infertility, with various pathogens affecting the reproductive system through different mechanisms. Early diagnosis, appropriate treatment, and preventive measures are essential to mitigate the impact of these infections on women’s reproductive health and fertility.

Acta Microbiologica Hellenica doi: 10.3390/amh70030032

Authors: Sara Boulmaiz Ammar Ayachi Widad Bouguenoun

This study assessed microbiological contamination in street-sold meat products, focusing on Enterobacterales and coagulase-negative staphylococci (CoNS) species and their antibiotic resistance. Chicken and mutton street foods like shawarma and brochettes were tested for bacterial load, species distribution. and resistance profiles. The results showed significant contamination, with Enterobacter cloacae (5.38 Log 10 CFU/g). Staphylococcus lentus and Staphylococcus xylosus were also common, reaching 6.23 Log 10 CFU/g in some samples. Contamination levels varied significantly by food type, with chicken shawarma showing the highest risk. Antimicrobial susceptibility testing revealed high multidrug resistance, particularly among E. cloacae and Staphylococcus species. Biofilm formation an indicator of resistance was observed mainly in staphylococci and enhanced under fed-batch culture. These findings highlight public health concerns tied to poor hygiene and undercooking in street food environments. The study emphasizes the need for improved hygiene practices, standardized cooking methods, and systematic food safety monitoring to reduce contamination and antibiotic resistance risks.

Acta Microbiologica Hellenica doi: 10.3390/amh70030031

Authors: Patience B. Tetteh-Quarcoo Joana Twasam John Ahenkorah Bismarck Afedo Hottor Nicholas T. K. D. Dayie Stephen Opoku-Nyarko Peter Ofori Appiah Emmanuel Afutu Fleischer C. N. Kotey Eric S. Donkor Emilia Asuquo Udofia Nii Koney-Kwaku Koney Benjamin Arko-Boham Kevin Kofi Adutwum-Ofosu

Syphilis, which is caused by Treponema pallidum, remains one of the most common congenital infection worldwide and has tremendous consequences for the mother and her developing foetus if left untreated. The complexity of the exposure to this pathogen extends beyond the well-established clinical manifestations, as it can profoundly affect placental histomorphology. This study aimed to compare T. pallidum-exposed placental villi structures with healthy placentae at term to evaluate the histomorphological differences using stereology. In this case-control study conducted at term (38 weeks ± 2 weeks), 78 placentae were collected from the hospital delivery suites, comprising 39 cases (T. pallidum-exposed) and 39 controls (non-exposed), who were gestational age-matched with other potential confounders excluded. Blood samples from the umbilical vein and placental basal plate were tested for syphilis, using rapid diagnostic test (RDT) kits for T. pallidum (TP) antibodies (IgG and IgM) to classify placentae as exposed to T. pallidum (cases) and non-exposed (controls). Tissue sections were prepared and stained with haematoxylin and eosin, and the mean volume densities of syncytial knots, foetal capillaries, syncytial denuded areas, and intervillous spaces were estimated using stereological methods. Statistical analysis was performed to compare the mean values between the case and control groups. Stereological assessment revealed significant differences between the T. pallidum-exposed and non-exposed groups with regard to syncytial knots (p < 0.0001), syncytial denudation (p < 0.0001), and foetal capillaries (p < 0.0001), but no significant difference in the intervillous space was found (p = 0.1592). Therefore, our study shows, for the first time, that the histomorphology of human placental villi appears to be altered by exposure to T. pallidum. It will, therefore, be interesting to determine whether these changes in the placental villi translate into long-term effects on the baby.

Acta Microbiologica Hellenica doi: 10.3390/amh70030030

Authors: Tuhina Das Arkaprava Das Neha Das Rittika Mukherjee Mousumi Saha Dipanwita Das Agniswar Sarkar

The excessive use of antimicrobials drives the emergence of multidrug resistance (MDR) in bacterial strains, which harbor resistance genes to survive under diverse drug pressures. Such resistance can result in life-threatening infections. The predominance of MDR Pseudomonas spp. poses significant challenges to public health and environmental sustainability, particularly in ecosystems affected by human activities. Characterizing MDR Pseudomonas spp. is crucial for developing effective diagnostic tools and biosecurity protocols, with broader implications for managing other pathogenic bacteria. Strains were diagnosed through 16S rRNA PCR and sequencing, complemented by phylogenetic analysis to evaluate local and global evolutionary connections. Antibiotic susceptibility tests revealed extensive resistance across multiple classes, with MIC values surpassing clinical breakpoints. This study examined the genetic diversity, resistance potential, and phylogenetic relationships among Pseudomonas aeruginosa strain DG2 and Pseudomonas fluorescens strain FM3, which were isolated from solid waste dump sites (n = 30) and dairy farms (n = 22) in West Bengal, India. Phylogenetic analysis reveals distinct clusters that highlight significant geographic linkages and genetic variability among the strains. Significant biofilm production under antibiotic exposure markedly increased resistance levels. RAPD-PCR profiling revealed substantial genetic diversity among the isolates, indicating variations in their genetic makeup. In contrast, SDS-PAGE analysis provided insights into the protein expression patterns that are activated by stress, which are closely linked to MDR. This dual approach offers a clearer perspective on their adaptive responses to environmental stressors. This study underscores the need for vigilant monitoring of MDR Pseudomonas spp. in anthropogenically impacted environments to mitigate risks to human and animal health. Surveillance strategies combining phenotypic and molecular approaches are essential to assess the risks posed by resilient pathogens. Solid waste and dairy farm ecosystems emerge as critical reservoirs for the evolution and dissemination of MDR Pseudomonas spp.

Acta Microbiologica Hellenica doi: 10.3390/amh70030029

Authors: Lazaros Tsoukalas Constantine M. Vassalos Nikos Gkitsakis Panagiota Gkotzamani Eleni Gkoumalatsou Konstantia Bakalianou Eleftheria Palla Stavroula Baka Constantina Skanavis Evdokia Vassalou

Trichomonas vaginalis infection (TVI) is the most common curable sexually transmitted infection (STI). In this study, we aimed to assess the performances of different tests for TVI diagnosis in symptomatic Greek women, evaluating the TVI prevalence rate (PR) in Greece and comparing the latter with TVI-PR estimates from Europe. A laboratory-based cross-sectional analysis and a meta-analysis were conducted. Of 399 symptomatic Greek women, 17 had TVI, corresponding to a TVI-PR of 4.3%. The commercial nucleic acid amplification test (NAAT) achieved a sensitivity of 94.1%, which was 6% higher than the sensitivity of the culture method, 35% higher than that of the wet mount test, and 59% higher than that of the Giemsa stain test. The wet mount test achieved the lowest positive predictive value of 76.9%. All the tests had high specificity levels and negative predictive values. Data from 34 European TVI-PR studies in symptomatic women were pooled. The TVI-PR established in our study was similar to the TVI-PR estimates of 4.8% in Europe and 4.5% in Greece, with the second being higher than those of 2.1% in Northwestern Europe and 1.5% in Southern Europe but closer to that of 6.7% in Türkiye. In Greece, a European country with a relatively high TVI-PR among symptomatic women, the highly sensitive and specific, automated, point-of-care NAAT would facilitate rapid, accurate TVI diagnosis and the treatment of this target population to meet the WHO’s goal of ending STI epidemics by 2030.

Acta Microbiologica Hellenica doi: 10.3390/amh70030028

Authors: Wahyu Siswandari Dyahayu Nisa Arini Ali Taqwim Shinta Prima Ardinas Dwi Utami Anjarwati Lantip Rujito

Beta-thalassemia major is an inherited disorder that requires lifelong blood transfusions, with the risk of complications including poor oral health and dental caries. The objective of this study was to compare the oral microbiome diversity and composition in transfusion-dependent thalassemia patients and relate it to oral hygiene and dental caries. A cross-sectional analysis of 35 patients of beta-thalassemia major aged 6–18 years was performed. The status of oral hygiene was examined through the Oral Hygiene Index—Simplified (OHI-S) and Decayed, Missing, and Filled Teeth (DMFT) index. Saliva was taken for DNA extraction, followed by the 16S rRNA sequencing of V3-V4 hypervariable regions. The bioinformatics pipeline in QIIME2 was utilized for analyzing the comparison of microbial composition and diversity in groups of varying oral hygiene status and severity of caries. Metagenomic analysis revealed 3334 Amplicon Sequence Variants (ASVs), of which the most prevalent genera were Streptococcus, Haemophilus, Veillonella, Rothia, and Prevotella. High-oral-hygiene groups presented increased levels of cariogenic bacteria, while moderate-oral-hygiene groups presented an equilibrated microbiome. No statistically significant differences in microbial diversity were found between the study groups (p > 0.05). This study sheds light on the critical importance of oral hygiene in microbiome diversity in patients with beta-thalassemia major.

Acta Microbiologica Hellenica doi: 10.3390/amh70030027

Authors: Shirajum Monira K. A. N. K. Karunarathna Mohammad Ezazul Hoque Iqubal Md Abu Sayeed Tazrina Rahman Md Kaisar Rahman Shahneaz Ali Khan Philip P. Mshelbwala John I. Alawneh Mohammad Mahmudul Hassan

Dengue virus infection (DVI), a mosquito-borne arboviral infection, is prevalent in tropical and subtropical regions, including Bangladesh, where incidence has surged over the past three decades—particularly in urban and peri-urban areas. This study investigates the factors influencing DVI seropositivity among clinically suspected patients admitted to the selected hospitals of Savar, Dhaka, and Chattogram. Data were collected from 850 clinically suspected patients admitted to two hospitals in Savar, Dhaka, and two in Chattogram during 2019. Questionnaire responses and laboratory test results (NS1, IgM, and IgG) were analyzed using descriptive statistics, chi-square tests, and logistic regression. Out of 450 admissions in Savar, 330 tested positive, while Chattogram reported 145 positives from 400 cases. No significant differences were observed between regions in relation to hospital type, season, gender, or household preventive measures. In Savar, DVI status was significantly associated with season, mosquito net use, and patient contact. In Chattogram, household repellent use and patient contact were key factors. Diagnostic tests varied in detection capability. These findings can inform targeted intervention strategies and public health messaging, such as promoting personal protection measures and community awareness campaigns, particularly in high-incidence urban settings. However, further research across diverse geographic and socio-ecological contexts is needed to enhance the generalizability and policy relevance of these results.

Acta Microbiologica Hellenica doi: 10.3390/amh70030026

Authors: Vinh Xuan Le Kieu Thi Nguyen Minh Van Nguyen Tram ThiHoang Ho Tuyen ThiThanh Tran Cong Phi Dang Van Cao Thuy Thi Le

Vaginitis is a major health concern among women, with inadequate treatment potentially leading to reproductive complications. This study aimed to assess vaginitis prevalence, identify predominant pathogens, and evaluate associated risk factors among female patients at Da Nang Dermato-Venereology Hospital. A prospective study of 796 female patients undergoing physical examinations was conducted, with demographic, clinical, and microbiological data collected. Vaginitis was diagnosed in 180 (22.6%) of 796 female patients, predominantly caused by Candida spp. (66.1%) and bacterial pathogens (31.7%), with no Trichomonas vaginalis detected, and was most prevalent in women aged 20–30 years. Poor hygiene practices, including infrequent sanitary pad changes (OR = 5.01, p < 0.001) and routine vaginal douching (OR = 6.77, p < 0.001), were significantly associated with vaginitis. The Amsel criteria showed high specificity (99.1%) for bacterial vaginosis diagnosis. The absence of T. vaginalis suggests a potential shift in the epidemiology of vaginal infections. The Amsel criteria are a practical diagnostic tool in resource-limited settings. Our findings highlight the need for targeted hygiene education to reduce vaginitis prevalence in Vietnam.

Acta Microbiologica Hellenica doi: 10.3390/amh70020025

Authors: Paulo Afonso Luís Cardoso Ana Sofia Soares Manuela Matos Hélder Quintas Ana Cláudia Coelho

Talaromyces marneffei is a zoonotic dimorphic pathogen endemic to Southeast Asia and reported in 33 countries, with an estimated 17,300 human cases and 4900 deaths annually. We aimed to identify the best available evidence regarding the epidemiological and clinical features and the prevalence of T. marneffei reported in companion animals, wildlife, and humans in Europe. A systematic literature review was conducted by searching three databases under PRISMA guidelines for “Talaromyces marneffei” or “talaromycosis” in Europe or the equivalent. References from the obtained publications were also checked to identify additional papers that met the inclusion criteria. The search was not limited by language or year. Studies published until 30 April 2025 were included. Due to the limited number of publications on animals, the geographic scope was expanded to a global level. Of the 915 studies identified, 33 were eligible and categorised according to the subject they addressed: talaromycosis in humans (n = 26), talaromycosis in companion animals (n = 4), and talaromycosis in wildlife (n = 3). Talaromycosis has been reported 28 times in 11 different European countries among humans. Additionally, one case of T. marneffei in wildlife has been documented in Europe. There is a potential liaison host between bamboo rats and humans. Talaromycosis is an emerging planetary neglected disease. Confusion with other diseases and potential misdiagnosis leads to delayed diagnosis and unnecessary risk to lives. Immunocompromised and HIV-positive patients should be screened for talaromycosis. The unexplained worldwide reports in atypical species and locations prompt a call to action for a more proactive search for T. marneffei in other domestic and wild animals, as well as in soil, to fully understand its hosts and transmission, which must incorporate the Stockholm Paradigm and Planetary Health perspectives.

Acta Microbiologica Hellenica doi: 10.3390/amh70020024

Authors: Úrsula-Eva Eñeso Efuá Silvia Herrera-León Fátima Patabobe Pascual Erasmo Owono Agustín Benito

Acute diarrhoeal disease caused by antibiotic-resistant diarrhoeagenic bacteria is a significant global public health issue, particularly in low- and middle-income countries. This study provides the first molecular characterisation of antimicrobial resistance profiles, including the detection of CTX-M-15 and CTX-M-55 extended-spectrum beta-lactamases (ESBLs), among diarrhoeagenic Enterobacterales in Bioko Island, Equatorial Guinea, offering novel epidemiological insights into an understudied region. This study investigated the antibiotic resistance profiles of pathogenic bacteria isolated from diarrhoeal samples on Bioko Island. A total of 153 clinical isolates were collected between 1 February and 30 May 2014, and antimicrobial susceptibility testing was performed at Loeri Comba Polyclinic (Malabo) using the Kirby–Bauer method. The molecular characterisation of β-lactamase-associated genes was performed on different isolates of diarrhoeagenic pathotypes—144 Escherichia coli, 7 Salmonella enterica, and 2 Shigella flexneri—at the National Centre for Microbiology (Majadahonda, Spain). High resistance rates were detected against ampicillin (98%), tetracycline (93.5%), sulfonamides (94.8%), sulfamethoxazole–trimethoprim (88.2%), and cefotaxime (78.8%), while moderate rates of resistance were noted for ciprofloxacin (26.7%), and all isolates remained susceptible to imipenem. Of the isolates, 107 (69.9%) produced either single or multiple β-lactamases. Among these, 73 (68.2%) harbored classical β-lactamases, specifically TEM and OXA-1 types, representing 47.7% of the total sample. Additionally, 34 (31.8%) of the isolates were identified as producers of extended-spectrum β-lactamases (ESBLs), specifically CTX-M enzymes. Sequencing identified CTX-M-15 and CTX-M-55 variants. The predominant ESBL-producing bacteria were enteroaggregative Escherichia coli (56.2%), followed by enteropathogenic and enterotoxigenic E. coli. These findings confirm the circulation of multidrug-resistant diarrhoeagenic Enterobacterales in Equatorial Guinea, raising concerns about limited treatment options due to widespread resistance to multiple antibiotic classes, including third-generation cephalosporins and quinolones. The most important conclusion drawn from this study is that a high percentage of diarrhoeagenic bacteria have an antibiotic resistance and multi-resistance profile, especially to beta-lactams and other groups of antibiotics such as tetracyclines and sulphonamides. There is also a moderate prevalence of isolates carrying ESBLs on Bioko Island, Equatorial Guinea, which could indicate the inappropriate use of antimicrobials.

Acta Microbiologica Hellenica doi: 10.3390/amh70020023

Authors: Thuy Thi Le Trinh ThiDoan Nguyen Ngan DangThu Nguyen Hoang Huy Nguyen Hoa ThiMinh Hoang Lam ThiKieu Bui Minh Van Nguyen Cong Phi Dang Van Cao

Sexually transmitted infections (STIs) remain a global issue, causing health problems and financial burdens. This study aimed to provide an update on the invasive pathogens and analyze any associated factors in patients visiting Da Nang Dermato-Venereology Hospital who were diagnosed with genital tract infections in males and lower genital tract infections in females; 535 participants underwent clinical examinations and microbiological tests to identify the invasive microorganisms, before we analyzed previously gathered laboratory results and associated risk factors. The rate of infection was 37.6% amongst 535 participants. Treponema pallidum infection accounted for the highest rate of 21.3%, followed by HSV, standing at 6%. The prevalence of syphilis infection was highest in the 20–29 age group, standing at 51.7%. There was a positive correlation between age under 20 and infected conditions (OR = 3.78, 95% CI: 1.41–10.11, p = 0.008). Having multiple sexual partners was identified as a risk factor for infection, as those with three or more sexual partners showed a high correlation (OR = 3.19, 95% CI: 1.44–7.05, p = 0.004). The high syphilis prevalence among young adults and teenagers underscores the need for improved STI education and screening programs in Vietnam.

Acta Microbiologica Hellenica doi: 10.3390/amh70020022

Authors: Lorenzo Ippoliti Federica Crivaro Luca Coppeta Giuseppina Somma Filippo Lecciso Gianmarco Manili Viola Giovinazzo Margherita Iarossi Cristiana Ferrari Antonio Pietroiusti Andrea Magrini

Hepatitis B and C (HBV and HCV) infections persist as significant public health concerns. Specific occupational groups, such as waste collectors, continue to face elevated risk due to exposure to contaminated materials. Research studies have underscored heightened infection rates, notably from needle prick injuries. The present study aspires to re-evaluate the prevalence of HBV and HCV among waste collectors and to scrutinize associated risk factors, thereby contributing to the development of effective public health and occupational safety strategies. The study analyzed data from 116 Italian waste collectors who were undergoing regular occupational visits, examining demographics, health conditions, HBV immunization, and annual blood tests for the HBsAg, HBsAb, and HCVAb. The HBsAb was detected in 66 individuals (56.9%), while the HCVAb was found in 4 (3.4%). Logistic regression showed HBV immunization and longer job experience to be significant factors associated with HBsAb presence. Waste collection may increase HBV infection risk due to occupational exposure, unlike HCV, which requires blood-to-blood contact. Preventive strategies, including education, protective equipment, and HBV vaccination, are essential. Ensuring vaccination coverage among waste collectors could reduce infection risk. Further research should assess the occupational risks and the effectiveness of preventive measures.

Acta Microbiologica Hellenica doi: 10.3390/amh70020021

Authors: Pitakthai Chamtim Nachon Raethong Roypim Thananusak

Antimicrobial resistance (AMR) is a growing concern in laboratory animals, where antibiotic use can disrupt the gut microbiome and promote resistant strains. Rabbits, commonly used in biomedical research, are particularly susceptible to gut dysbiosis, increasing the risk of infection and subsequent antibiotic use. This study used 16S rRNA amplicon sequencing and PICRUSt2 to predict resistance-related functions in rabbits under standard laboratory conditions. Among 2427 amplicon sequence variants, 42 functional classes were identified, with AMR comprising 1.55% of the predicted functions, including beta-lactam, vancomycin, and cationic antimicrobial peptide resistance. These AMR functions were associated with commensal genera such as Bacteroides and Ruminococcus, while no associations were observed with pathogens such as Escherichia or Salmonella. The study provides functional evidence of intrinsic AMR in the rabbit gut microbiome and underscores the importance of antimicrobial stewardship in laboratory animal research.

Acta Microbiologica Hellenica doi: 10.3390/amh70020020

Authors: Sofia Chiletzari Anastasia Barbouni Konstantinos Kesanopoulos

Surgical site infections (SSIs) are one of the most common causes of hospital-acquired infections worldwide, with significant clinical and economic implications. The aim of this review was to summarize the latest body of evidence on associations between microbial air load and SSIs. The systematic review was conducted using the revised Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA, 2020) method. Pubmed and Scopus databases were searched for the period 2014–2024. English language articles were searched for their reports on the microbial burden of operating room air and its association with surgical site infections. The present review includes a total of 36 articles related to microbial air load as an aggravating factor to air quality in the operating room and its association with SSIs. A direct correlation between microbial air load and the occurrence of SSIs was established through sampling methods and genetic analysis. A lack of consensus on the effectiveness of laminar air flow (LAF) systems was underlined, while temperature-controlled air flow seemed a promising alternative. One study found that each additional person in the operating room increases the number of bacterial colonies by 4.93 CFU/m3 while another did not find significant changes in air quality. More than 20 air changes per hour (ACH) appeared to have better results in improving the quality of the air in the operation room. Airborne microbial contamination is multifactorial, and for some of those factors, a revision of the guidelines seems necessary. Artificial Intelligence (AI) and Next-Generation Sequencing methods show great promise for improving air quality in the future. This review calls for the implementation of international guidelines regarding air contamination limits in operating rooms and standardized air sampling methods, as well as further research for the efficacy assessment of air flow systems and emerging technologies based on AI in order to reduce the burden of SSIs and improve patient outcomes.

Acta Microbiologica Hellenica doi: 10.3390/amh70020019

Authors: Alejandro Borrego-Ruiz Juan J. Borrego

The vaginal microbiome can be perturbed by various intrinsic and extrinsic factors, resulting in a state of dysbiosis that decreases the abundance of commensal lactobacilli and often leads to pathological conditions such as bacterial vaginosis, yeast infections, sexually transmitted infections, and other vaginal disorders. This narrative review explores the molecular and pathophysiological mechanisms of several microbial diseases associated with the dysbiosis of the vaginal microbiome, as well as the efficacy of therapeutic tools for these conditions, such as antibiotic treatment and the use of live biotherapeutic products. A non-systematic, narrative approach was employed. Searches and data extraction were performed using the PubMed and Scopus databases between January and February 2025. All reviewed studies reported vaginal microbiome dysbiosis, with microbial pathogens inducing a specific immune response in the host. Current treatments for vaginal microbiota dysbiosis-related pathologies often result in high relapse and recurrence rates, suggesting microbial resistance and the need for alternative therapeutic strategies. In turn, live biotherapeutic products have demonstrated beneficial effects, restoring microbial balance in dysbiotic conditions. While these findings suggest promising potential for live biotherapeutic products, further rigorous clinical studies are necessary to gain a deeper understanding of the female genital tract ecosystem and to identify novel biomarkers along with their associated health implications. Moreover, the development of new diagnostic and management strategies will facilitate personalized therapeutic approaches. Ultimately, a comprehensive perspective on vaginal care is pivotal, taking into account both microbial and immune dynamics to enhance women’s health outcomes.

Acta Microbiologica Hellenica doi: 10.3390/amh70020018

Authors: Jean Demarquoy

The human microbiota plays a crucial role in maintaining host health through its considerable influence on immune function, nutrient metabolism, and overall homeostasis. While trace metals such as cobalt, lithium, and nickel are essential micronutrients at low concentrations, their increasing environmental accumulation presents emerging risks for microbial dysbiosis and related systemic health effects. This review examines the dual role of these trace metals as both beneficial nutrients and potential disruptors of microbial balance. Specifically, cobalt supports microbial diversity through its role in vitamin B12 synthesis, but excessive exposure can lead to dysbiosis. Lithium, beneficial at therapeutic concentrations by enhancing beneficial microbial populations, adversely affects gut barrier integrity by promoting inflammation and epithelial damage at higher concentrations. Similarly, nickel participates in essential enzymatic activities but promotes dysbiosis and inflammatory responses at elevated exposures. Furthermore, the growing environmental contamination by these metals poses risks to food systems and various microbial communities in the environment. Highlighting these environmental concerns, this review calls for sustainable management and multidisciplinary research to mitigate health risks to mitigate health risks associated with trace metal exposure.

Acta Microbiologica Hellenica doi: 10.3390/amh70020017

Authors: Md. Maidul Islam Md Ahosanul Haque Shahid K. H. M. Nazmul Hussain Nazir

In developing countries like Bangladesh, livestock is one of the main sources of income. Among several infectious diseases, the Gram-positive bacterium Bacillus anthracis causes a zoonotic disease named anthrax. Animal anthrax outbreaks are a frequently occurring problem in Bangladesh. Our present study aims to molecularly identify and characterize B. anthracis from three districts of Bangladesh by 16S rRNA gene sequencing. B. anthracis was confirmed in soil, meat, and blood samples using PCR. Anthrax-affected soil (n = 128), blood (n = 1), and meat (n = 2) samples were analyzed using PCR. One of the positive samples was randomly chosen for sequencing, and MEGA5 software was used to generate the phylogenetic tree from the sequencing result. A total of 21 (16.40%) soil samples and all of the blood and meat samples were positive for the presence of bacteria, confirmed by PCR. The 16S rRNA gene of B. anthracis Sirajganj-1 was identical to that of other strains. To fulfill the Sustainable Development Goals, it is important to control zoonotic diseases. Our results may help discover the virulent genes of B. anthracis for future investigation and control this zoonotic disease. Also, a proper awareness of vaccination and effective surveillance system is important to eradicate any kind of zoonotic disease in developing nations.

Acta Microbiologica Hellenica doi: 10.3390/amh70020016

Authors: Sarah Parfaite Ambourouet Franck Mounioko Patrice Makouloutou-Nzassi Monique Nzale Barthelemy Ngoubangoye Larson Boundenga

The present study investigates the prevalence and diversity of Plasmodium and Trypanosoma infections in Allochrocebus solatus, a vulnerable primate species native to Gabon. Using molecular techniques like nested PCR and phylogenetic analysis, we found 34.0% infection rate for malaria parasites infection, 21.3% for Trypanosoma spp., and 12.8% co-infections. Additionally, Hepatocystis was exclusively detected among malaria parasites, while Trypanosoma brucei brucei, T. vivax, and T. congolense were identified. These results underscore the complex host–parasite interactions influenced by captivity and the ecological and immunological consequences of such infections, particularly the increased susceptibility associated with captivity-induced stress. This preliminary study highlights the need for ongoing surveillance to mitigate health risks in primates and prevent potential zoonotic spillovers, providing critical data for conservation efforts.

Acta Microbiologica Hellenica doi: 10.3390/amh70020015

Authors: Alkmena Kafazi Eleni Apostolopoulou Eymorfia Andreou Alexandra Gavala Evagelos Stefanidis Fwteini Antwniadou Christos Stylianou Theodoros Katsoulas Pavlos Myrianthefs

Device-associated infections (DAIs) are a significant public health concern because of their attributable mortality, along with the extra length of stay and cost. This two- year prospective surveillance study aimed to assess the incidence of DAIs and their clinical impact on four Greek adult medical-surgical Intensive Care Units (ICUs). Centers for Disease Control and Prevention (CDC) definitions were used to diagnose DAIs. Of the 500 patients hospitalized for 12,624 days, 254 (50.8%) experienced 346 episodes of DAIs. The incidence of DAIs was 27.4 episodes per 1000 bed-days. The incidence of ventilator-associated events (VAEs), central line-associated bloodstream infections (CLABSIs), and catheter-associated urinary tract infections (CAUTIs) was 20.5 episodes per 1000 ventilator-days, 8.6 episodes per 1000 central line-days, and 2.5 episodes per 1000 catheter-days, respectively. The most common pathogens isolated were Acinetobacter baumannii (35.7%) and Klebsiella pneumoniae (29.9%). All gram-negative pathogens were carbapenem-resistant. The ICU’s mortality was 44.9% for patients with DAIs and 24.8% for patients without a DAI (attributable mortality 20.1%, p < 0.001), while the mean ICU length of stay was 34.5 days for patients with DAIs and 15.6 days for patients without a DAI (attributable length of stay 18.9 days, p < 0.001). The high incidence of multidrug-resistant pathogens and the attributable length of stay and mortality of DAIs emphasize the need to establish an organized antimicrobial surveillance program and implement a care bundle for DAI prevention in ICUs with personnel educational training, monitoring, and feedback.

Acta Microbiologica Hellenica doi: 10.3390/amh70020014

Authors: Aikaterini Sakagianni Christina Koufopoulou Petros Koufopoulos Georgios Feretzakis Athanasios Anastasiou Nikolaos Theodorakis Pavlos Myrianthefs

Antibiotic resistance is a global health crisis exacerbated by the misuse of antibiotics in healthcare, agriculture, and the environment. In an intensive care unit (ICU), where high antibiotic usage, invasive procedures, and immunocompromised patients converge, resistance risks are amplified, leading to multidrug-resistant organisms (MDROs) and poor patient outcomes. The human microbiome plays a crucial role in the development and dissemination of antibiotic resistance genes (ARGs) through mechanisms like horizontal gene transfer, biofilm formation, and quorum sensing. Disruptions to the microbiome balance, or dysbiosis, further exacerbate resistance, particularly in high-risk ICU environments. This study explores microbiome interactions and antibiotic resistance in the ICU, highlighting machine learning (ML) as a transformative tool. Machine learning algorithms analyze high-dimensional microbiome data, predict resistance patterns, and identify novel therapeutic targets. By integrating genomic, microbiome, and clinical data, these models support personalized treatment strategies and enhance infection control measures. The results demonstrate the potential of machine learning to improve antibiotic stewardship and predict patient outcomes, emphasizing its utility in ICU-specific interventions. In conclusion, addressing antibiotic resistance in the ICU requires a multidisciplinary approach combining advanced computational methods, microbiome research, and clinical expertise. Enhanced surveillance, targeted interventions, and global collaboration are essential to mitigate antibiotic resistance and improve patient care.

Acta Microbiologica Hellenica doi: 10.3390/amh70020013

Authors: Chen Hazout Mona Saif Shalom Ben-Shimol Moshe Shmueli Oren Ziv Zvi H. Perry Daniel Yafit

Cervical lymphadenitis in children, often caused by bacterial infections, may require surgical drainage if initial antibiotic treatment fails. Identifying factors associated with surgical intervention may aid in treatment decision-making and improve patient outcomes. We assessed the demographic, clinical, and laboratory factors associated with the need for surgical drainage in children diagnosed with cervical lymphadenitis. We conducted a retrospective cohort study of children diagnosed with cervical lymphadenitis or abscesses between 2015 and 2021. Data collected included demographics, clinical presentation, laboratory results, imaging findings, and treatment outcomes. Surgical intervention was compared to the conservative treatment group to identify predictors for drainage. Overall, 201 children were included; 87 (43%) underwent surgical drainage, while 114 (57%) received conservative treatment. In univariate analysis, young age (<3 years), leukocytosis (>15,000/mm3), and longer hospitalization duration (5.6 vs. 3.2 days, p < 0.001) were associated with surgical intervention. Methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) were the most common pathogens isolated from abscess cultures. In multivariate analysis, factors associated with surgical drainage included large lymph node size (>3 cm), erythema, and fluctuance in the physical examination and imaging (ultrasound) findings of abscess or phlegmon. Surgical intervention in pediatric cervical lymphadenitis was found to be associated with young age, large lymph nodes, erythema, and abscesses on imaging. Early assessment and recognition of these factors can guide the timely initiation of appropriate treatment, including surgery, when indicated.

Acta Microbiologica Hellenica doi: 10.3390/amh70020012

Authors: Rim Abbas Ali Salami Ghassan Ghssein

Tuberculosis (TB) is an infectious disease caused by bacteria that primarily target the lungs. The transmission of this disease occurs through the air in the form of droplet nuclei. Unfortunately, there has been an emergence of resistance to strains of such infections, such as multidrug- as well as extensively drug-resistant strains. Healthcare workers (HCWs) are particularly vulnerable to contracting TB due to their direct contact with patients. This study aims to evaluate the knowledge, attitude, and practices among Lebanese healthcare workers towards TB and its resistant forms, particularly multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). This study is a cross-sectional, descriptive, questionnaire-based research study that was conducted on HCWs in Lebanon. A total of 517 HCWs were included in this study. The findings displayed that 48.52% of HCWs had good knowledge of TB and MDR-TB/XDR-TB, 49.52% had average knowledge, and 2.13% had bad knowledge. Moreover, only 16.25% had a good attitude, 71.92% had an average attitude, and 11.8% had a bad attitude. Furthermore, only 14.7% had good practices, 54.74% had average practices, and 30.56% had bad practices. Having a history of testing for TB was found to be related to increased attitude. Also, the history of having TB-infected family members was found to be linked to both increased attitude and practice scores. Moreover, this study highlights the idea that high knowledge scores do not mean high attitude or high practices scores. On the same note, acceptable attitude scores do not inflict acceptable practice scores. The findings of this study showed that there is an overall good knowledge regarding TB, MDR-TB, and XDR-TB, average attitude, and average-to-bad practices. Gaps are seen in all sectors, even knowledge, especially with matters related to the diagnosis of MDR-TB/XDR-TB and its treatment duration. Also, the attitude section revealed a gap in the understanding of the modes of transmission of such an infection.

Acta Microbiologica Hellenica doi: 10.3390/amh70020011

Authors: Esteban Zavaleta-Monestel Carolina Rojas-Chinchilla Adriana Anchía-Alfaro Diego Quesada-Loría Jonathan García-Montero Sebastián Arguedas-Chacón Georgia Hanley-Vargas

Laboratory-acquired infections (LAIs) pose significant risks to laboratory personnel, public health, and the environment, despite the implementation of biosafety measures. This study provides a comprehensive analysis of global LAIs reported from 1974 to 2024, identifying trends, causes, and pathogen distributions to address gaps in biosafety knowledge. A systematic literature review was conducted using databases such as PubMed, Cochrane, Google Scholar, and the American Biological Safety Association (ABSA). A total of 234 studies meeting strict inclusion criteria were analyzed. Bacterial pathogens accounted for 58.6% of reported incidents, followed by viruses at 36.1%. Procedural errors and accidents were the predominant causes of LAIs, with Brucella spp. being the most frequently reported pathogen, primarily in China. Temporal trends indicated a decline in incidents coinciding with the implementation of international biosafety regulations. However, disparities in incident reporting and compliance remain evident across countries. This study underscores the urgent need for a global regulatory framework, mandatory biosafety audits, a centralized incident database, and standardized training for high-containment laboratory personnel. Enhancing global collaboration, transparency in research, and adherence to ethical standards will further reduce LAI risks and strengthen public health security worldwide.

Acta Microbiologica Hellenica doi: 10.3390/amh70010010

Authors: Tsvetelina Velikova Hassan Ali Latchezar Tomov Tzvetan Velinov Snezhina Lazova

Since the nasopharynx serves as an ecological niche for Streptococcus pneumoniae, Corynebacterium spp., Haemophilus influenzae, Moraxella catarrhalis, etc., colonization is influenced by antimicrobial treatments, host immune responses, viral infections, and vaccines, often leading to local and systemic infections. We aimed to investigate the patterns of nasopharyngeal colonization and antimicrobial susceptibility of bacterial isolates in Bulgarian individuals under 20 years of age presenting with acute, protracted, and chronic cough. We analyzed 1383 samples using conventional culture methods, MALDI-TOF MS, antimicrobial susceptibility testing, and genetic analyses for Bordetella pertussis and Mycoplasma spp. Among 896 isolates, H. influenzae was the most prevalent (26.23%), followed by M. catarrhalis (23.55%), S. pneumoniae (22.54%), and S. pyogenes causing 7.59% of infections. In children (0–10 years), M. catarrhalis (198 isolates) and H. influenzae (142 isolates) were the most common pathogens, followed by S. pneumoniae (73 isolates), while in those aged 10–20 years, S. pneumoniae was the most common isolate (129), followed by H. influenzae (93) and M. pneumoniae (21). Colonization in children and young adults serves as a reservoir for pathogen transmission to adults, highlighting its significant public health implications. Monitoring bacterial colonization and resistance patterns remains essential to inform targeted prevention and treatment strategies.

Acta Microbiologica Hellenica doi: 10.3390/amh70010009

Authors: Hindol Ray Chana Weis Chioma Nwaeze Vincent Zhou Paramita Basu Arindam Mitra

Diabetic foot ulcers (DFUs) are a multifactorial pathophysiologic condition that occurs in patients with diabetes mellitus (DM). Approximately 9.1 to 26.1 million people are affected by DFUs annually. This condition can lead to progressive foot infections and, ultimately, foot amputation. Various microbes contribute to DFUs, including methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli can form biofilms composed of complex matrices that create a protective shield around the microorganisms, enhancing their survival and resistance to treatment. Biofilm formation is a critical virulence factor directly associated with the onset and persistence of DFUs. It not only complicates the clinical management of these ulcers but also facilitates antibiotic resistance, necessitating a comprehensive approach to treatment. Effective management strategies must therefore target biofilm formation, and the virulence factors associated with these pathogens. By addressing these elements, conventional antibiotics can be rendered more effective in treating diabetic foot ulcers. This approach aims not only to promote wound healing but also to address underlying causes and prevent further complications. This article seeks to highlight the significance of biofilm formation in DFUs, explore methodologies for studying this condition, as well as discuss demographic considerations and treatment options.

Acta Microbiologica Hellenica doi: 10.3390/amh70010008

Authors: Kyung-A Hyun Kyung-Hwan Boo Chang-Gu Hyun

In our previous study, Lentzea sp. JNUCC 0626 was isolated from Hwasun Gotjawal on Jeju Island, and its melanogenic effects were confirmed in B16F10 melanoma cells through the identification of 1-acetyl-β-carboline. In this study, we conducted a comprehensive taxonomic characterization of Lentzea sp. JNUCC 0626, including enzymatic activities, carbohydrate metabolism, growth conditions, and cellular composition. Major fatty acids identified were iso-C16:0, iso-C15:0, and C15:0 anteiso, with polar lipids such as diphosphatidylglycerol, phosphatidylethanolamine, and several unidentified lipids. Ubiquinone Q-9 was determined as the predominant respiratory quinone. Enzymatic activity analysis (API ZYM) showed alkaline phosphatase, esterase (C4), esterase lipase (C8), and leucine arylamidase activities, while carbohydrate metabolism analysis (API 50CHB) indicated acid production from esculin alone. Complete genome sequencing revealed a 10,602,950 bp linear chromosome and a 177,940 bp plasmid. This plasmid encodes essential plasmid-related genes, including a Type IV secretion system and ParA proteins critical for plasmid transfer and stability. These findings suggest that the plasmid in Lentzea sp. JNUCC 0626 could be utilized for developing host–vector systems to facilitate the combinatorial biosynthesis of novel bioactive compounds. Comparative genomic analysis identified Lentzea pudingi CGMCC 4.7319 as the closest relative, but significant genetic divergence (dDDH 46.7%, ANI 88.02%) strongly supports the classification of Lentzea sp. JNUCC 0626 as a novel species. AntiSMASH analysis revealed 34 biosynthetic gene clusters (BGCs), highlighting the strain’s capacity to produce diverse bioactive compounds. Finally, the JNUCC 0626 extract exhibited concentration-dependent NO inhibition in LPS-stimulated RAW 264.7 cells, demonstrating significant anti-inflammatory activity. This suggests that the secondary metabolites inferred from genomic analysis may contribute to these observed bioactivities.

Acta Microbiologica Hellenica doi: 10.3390/amh70010007

Authors: Andrea Fidanza Valeria Marinucci Lorenzo Vitale Giuseppina Poppa Ilaria Giusti Stefano Necozione Giandomenico Logroscino

One of the most dangerous and difficult side effects to treat after total hip arthroplasty (THA) is periprosthetic or superficial site infection. Blood and synovial fluid biomarkers have recently come into focus in addition to conventional systemic indicators of inflammation in order to assess their potential utility in the diagnosis of infections. Long pentraxin 3 (PTX3) appears to be a sensitive biomarker of acute-phase inflammation. The purpose of this study is to determine plasma PTX3 in patients undergoing THA and compare its trend with other common serum markers, such as CRP, D-dimer, procalcitonin, and ESR up to 30 days post-operatively. Patients with hip arthritis or avascular necrosis of the femoral head were consecutively enrolled in a single-center study. Each patient underwent blood testing for ESR, CRP, procalcitonin, D-dimer, and PTX3 levels before surgery and at 1, 3, 5, 15, and 30 days after THA. PTX3 was measured using the ELISA method. Other markers’ values and trends were compared with PTX3’s. A total of 50 patients met our inclusion criteria. When different trends were evaluated, PTX3 was found to have a trajectory and sensitivity comparable to other inflammatory markers. Notably, PTX3 changed more quickly than the other markers, with a sharp increase immediately post-operatively, followed by normalization at the 5-, 15-, and 30-day follow-ups, corresponding to the resolution of the inflammatory condition. However, 30 days post surgery, no patients exhibited signs or symptoms of early prosthetic infection. PTX3 is confirmed as a reliable and promising serum biomarker for tracking the level of inflammation in patients undergoing total hip replacements. Blood PTX3 values rise even more rapidly than CRP and procalcitonin and then quickly return to normal values when the inflammatory process resolves. One of the primary barriers to PTX3’s inclusion in routine studies on early periprosthetic infections is the waiting period for PTX3 sample analysis.

Acta Microbiologica Hellenica doi: 10.3390/amh70010006

Authors: Arpita Arsmika Sahu Somya Sephalika Nirmal Kumar Mohakud Bikash Ranjan Sahu

Non-typhoidal Salmonella (NTS) infection poses a significant public health challenge globally, particularly in developing countries like India. NTS, predominantly represented by S. enterica serovars, is a major cause of intestinal and extra-intestinal infections. This review provides a comprehensive overview of longitudinal analyses of the prevalence of NTS in different regions of India encountered in the last 20 years and their antimicrobial resistance patterns. We followed several research investigations published during 2000–2024 to examine the incidence and prevalence of different serovars of NTS in several parts of India and followed published articles on NTS showing resistance to different antibiotics. We pointed out NTS serovars, which are predominantly isolated in various human and non-human sources, as observed in several investigations conducted in different regions of India. Our analysis revealed that, among serovars detected from various sources, S. Typhimurium is the most predominant one occurring across both human and non-human sources, followed by S. Enteritidis and S. Weltevreden. The occurrence of similar serovars of Salmonella in both human and non-human sources may be due to zoonotic transmission between animals and humans. Extensive research conducted across many geographic locations reveals that NTS isolates exhibit resistance to several antibiotics, with multidrug-resistance (MDR) being more common. These MDR strains basically show resistance to three or more classes of antibiotics, including critically important antimicrobials such as nalidixic acid, ciprofloxacin, and third-generation cephalosporins. Temporal trends suggest an alarming increase in resistance to these antibiotics, particularly in serovars such as S. Typhimurium and S. Enteritidis. Overall, the current article sheds light on the urgent need for surveillance, judicious antibiotic use, and the development of alternative treatment strategies to combat the rising tide of antibiotic-resistant NTS strains.

Acta Microbiologica Hellenica doi: 10.3390/amh70010005

Authors: Qutaibah Oudat Anas Okour

The rising global prevalence of obesity and its associated metabolic disorders highlights the urgent need for innovative, sustainable interventions. Probiotics, as modulators of gut microbiota, have emerged as promising agents in weight management by influencing metabolic health. This mini-review explores the role of probiotics in modulating gut microbiota to support energy metabolism, appetite regulation, and fat storage. Evidence underscores the strain-specific benefits of probiotics, such as Lactobacillus gasseri SBT2055, Bifidobacterium breve B-3, and Akkermansia muciniphila, in reducing visceral fat, improving glucose metabolism, and mitigating obesity-related inflammation. The mechanisms underlying these effects include short-chain fatty acid (SCFA) production, modulation of appetite-regulating hormones, and improvements in gut barrier integrity. While the findings are promising, variability in outcomes highlights the importance of tailored probiotic interventions and underscores the need for standardized methodologies in future research. By addressing these challenges, probiotics can serve as integral components of personalized nutrition strategies, advancing both metabolic health and public health objectives.

Acta Microbiologica Hellenica doi: 10.3390/amh70010004

Authors: Kendall Winn-Swanson Lauren Kostich Mackenzie Castañeda-Childress Isiah Solis Jade Remillard Avaleen Agustin Demitri Gonzalez Víctor D. Carmona-Galindo

Microbial succession on urban masonry surfaces is a critical yet understudied aspect of environmental microbiology, with implications for public health within the One Health framework. This study investigated how building age, orientation, and vegetative cover influence microbial diversity on masonry, metal, and glass substrates at the University of La Verne, California. Biophysical characterizations were conducted, and microbial communities were analyzed using morphospecies richness and DNA sequencing. Significant variation in microbial species richness (χ2 = 20.3882, p = 0.0011) and diversity (Fisher’s LSD, p < 0.05) was observed. Masonry surfaces exhibited the highest microbial diversity, with a mean richness of 23 morphospecies compared to 14 on metal and 12 on glass. Penicillium fungi dominated masonry sites, comprising 45% of colonies, while Pseudomonas and Klebsiella were more prevalent on metal and glass surfaces (35% and 28%, respectively). Microbial succession did not follow a linear progression but showed non-sequential shifts influenced by local conditions. The abundance of Penicillium, known for antibiotic production, raises concerns about spreading antibiotic resistance genes. Opportunistic pathogens further highlight potential health risks. These findings underscore the importance of understanding primary successional processes in urban environments to manage microbial communities and mitigate public health risks.

Acta Microbiologica Hellenica doi: 10.3390/amh70010003

Authors: Cecilia Salzillo Andrea Marzullo

The COVID-19 pandemic has highlighted several cardiovascular complications, including myocarditis, which can be a significant cause of sudden cardiac death in young people. SARS-CoV-2 infection can cause cardiac muscle inflammation through direct mechanisms, such as viral invasion of myocardial cells, and indirect mechanisms, such as the systemic inflammatory response. Myocarditis can lead to life-threatening electrical dysfunctions and arrhythmias. Although post-infection myocarditis is more common, rare cases of post-vaccination myocarditis have also been reported, especially with mRNA vaccines. However, these post-vaccination cases tend to be mild and self-limiting, with a good response to treatment. Despite the associated risks, the benefits of vaccination far outweigh the risks, significantly reducing the incidence and severity of COVID-19 infections and related heart complications. It is crucial to continue surveillance and research to better understand the association between COVID-19, myocarditis and sudden cardiac death in the young and improve prevention and intervention strategies. In this literature review, we analyzed the pathogenetic mechanisms and histological features of myocarditis associated with COVID-19 and its vaccination, and focused on the correlation with sudden cardiac death.

Acta Microbiologica Hellenica doi: 10.3390/amh70010002

Authors: Eugene Y. H. Yeung

The safety precautions required for certain pathogens are different in clinical laboratories and patient-facing healthcare settings, causing confusion for laboratorians and infection preventionists. The current review aims to summarize information from reputable Government of Canada guidance commonly used in clinical laboratories in Canada, including the Government of Canada Human Pathogens and Toxins Act and Regulations, the ePATHogen—Risk Group Database, biosafety directives and advisories, Transportation of Dangerous Goods Regulations, and the Canadian Biosafety Standard (2022). Guidelines from the Centers for Disease Control and Prevention’s (CDC) Biosafety in Microbiological and Biomedical Laboratories (2020), Clinical and Laboratory Standard Institution’s (CLSI) M29 Protection of Laboratory Workers from Occupationally Acquired Infections (2014), and Association of Public Health Laboratories’s Biothreat Agent Bench Cards for the Sentinel Laboratory (2018) were also used to supplement specific details. In comparison, information regarding infection prevention and control practices in patient-facing healthcare settings was summarized: Public Health Agency of Canada: Routine Practices and Additional Precautions for Preventing the Transmission of Infection in Healthcare Settings (2017) and CDC Infection Control Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings (2007). Contrasting levels of precautions exist between laboratories and patient-facing settings, especially for endemic fungi and certain security-sensitive biological agents. Acknowledging this contrast may facilitate risk communication relative to the counterparts to minimize the threat and disease effects and ensure public confidence.

Acta Microbiologica Hellenica doi: 10.3390/amh70010001

Authors: Leda Viegas de Carvalho Filipe Soares Nogueira Francisco Vale Patrícia Nazaré Elisa Pereira Bárbara Gaspar Daniel Gomes Pinto

Cervical tuberculosis is a rare form of genital tuberculosis. A case of a 73-year-old woman who presented with cervical wall thickening on magnetic resonance imaging, suggesting an invasive malignant neoplasm, is documented. Cervical cone excision was performed for histopathological study. Microscopy showed epithelioid granulomas, without appreciable caseous necrosis, in the wall of the uterine cervix, associated with erosion of the overlying cervical mucosa. Histochemical stains for microorganisms (Ziehl–Neelsen, Grocott, and Warthin–Starry) were negative. Immunohistochemistry for Treponema pallidum revealed scarce, spiral-shaped bacilli, which raised the diagnostic possibility of secondary syphilis. The serological study for syphilis was negative, however. Polymerase chain reaction (PCR) tests for Mycobacterium tuberculosis and Treponema pallidum were performed in the formaldehyde-fixed, paraffin embedded tissue and resulted positive for Mycobacterium tuberculosis and negative for Treponema pallidum, confirming the diagnosis of cervical tuberculosis. Our objective was to report a rare case of cervical tuberculosis, discussing the advantages and limitations of complementary techniques used in the pathological diagnosis of infectious agents and highlighting diagnostic pitfalls. In conclusion, correct microbiological diagnosis requires the implementation of integrated workflows employing complementary techniques in a multidisciplinary setting to improve the accuracy of histopathological examination in infectious diseases.

Acta Microbiologica Hellenica doi: 10.3390/amh69040029

Authors: Anna Papa

Viruses transmitted by arthropods (arboviruses) pose a global public health threat. Sporadic cases or outbreaks caused by West Nile virus, Crimean–Congo haemorrhagic fever virus, tick-borne encephalitis virus, and phleboviruses are often reported in Europe. Recently, they expanded their distribution in geographic areas where they had never been observed before, while tropical viruses, like Dengue, Chikungunya, and Zika, started to cause autochthonous cases and outbreaks following the return of viraemic travellers from endemic countries. The primary or secondary vectors of these viruses are established in Europe, and the incidence of arboviral diseases is expected to increase due to several anthropogenic and/or environmental factors (mainly climate change, which affects the survival and amplification of the arthropod vectors). This is an update on the emerging arboviruses in Europe, associated challenges, and future perspectives.

Acta Microbiologica Hellenica doi: 10.3390/amh69040028

Authors: Aicha Essalhi Kaotar Nayme Fakhreddine Maaloum Abderrahmane Errami Khalid Zerouali Ahmed Aziz Bousfiha Assiya El Kettani

Community-acquired urinary tract infections (UTIs) represent a significant public health issue, primarily due to the increasing antibiotic resistance among uropathogens. This study assesses the resistance status of uropathogenic community Enterobacterales to various antibiotics, particularly aminoglycosides, and determines the prevalence of aminoglycoside-modifying enzyme (AME) genes, while investigating the coexistence of 16S rRNA methylating enzymes. We analyzed 628 clinical isolates of Enterobacterales obtained from 4282 cytobacteriological urine examinations at the Pasteur Institute Casablanca, Morocco, collected from October 2018 to December 2021. Identification and antibiotic susceptibility testing were conducted using the VITEK 2® COMPACT system, following CA-SFM guidelines. DNA extraction utilized the heat shock method, and subsequent PCR was performed. Gram-negative bacteria accounted for 85% of isolates, with Enterobacterales representing 91% of this group. E. coli (73%) and Klebsiella pneumoniae (20%) were the most common species among Enterobacterales. Resistance was particularly high for ampicillin (76.7%) and amoxicillin-clavulanate (58%). Among aminoglycosides, gentamicin and tobramycin resistance rates were 33.5% and 35%, respectively, while amikacin resistance was observed in 21.3% of isolates. High frequencies of AME genes were detected, with AAC(3′)-IIa (27.7%) and AAC(6′)-Ib (25.9%) being the most prevalent. Notably, no 16S rRNA methylation genes (rmtA, rmtB, rmtC, rmtD) were found. All tested strains exhibited biofilm-forming capacity, with K. pneumoniae demonstrating intense biofilm production. The study highlights a concerning trend of antibiotic resistance among uropathogenic Enterobacterales in the community setting, correlating genotype with resistance phenotype and emphasizing the need for enhanced surveillance and targeted treatment strategies.

Acta Microbiologica Hellenica doi: 10.3390/amh69040027

Authors: Melvin Mensah-Bonsu Christopher Doss Clay Gloster Perpetua Muganda

Ebola virus (EBOV) causes Ebola virus disease (EVD), a severe and often fatal hemorrhagic fever. Although much research has focused on host miRNA expression during EBOV infection, it has been discovered that EBOV itself also produces miRNAs. However, further studies are needed to fully comprehend the role of these EBOV-encoded miRNAs in infection and disease development. This study aimed to identify known and novel EBOV-encoded miRNAs and their potential functions in the pathogenic mechanisms of EBOV. We reanalyzed previously available small RNASeq data to identify the miRNAs and predict their cellular targets and functions. We identified four EBOV-encoded miRNAs—EBOV-mir-M1 (4390–4414), EBOV-mir-M4, EBOV-mir-M2 (8288–8309), and EBOV-mir-M3 (9885–9906)—expressed specifically in Ebola-infected human adult retinal pigment epithelial (ARPE) cells. EBOV-mir-M1 (4390–4414) was expressed up to 19 times more than the other three miRNAs. The identified miRNAs were predicted to target genes associated with pathways such as calcium signaling, MAPK signaling, type I interferon signaling, and cytokine-mediated signaling, which play critical roles in Ebola infection and pathogenesis. This study contributes to our understanding of the role of EBOV-encoded miRNAs in infection and pathogenesis by demonstrating the expression of these miRNAs in human ARPE cells, providing insights into the mechanisms underlying EBOV pathogenesis.

Acta Microbiologica Hellenica doi: 10.3390/amh69040026

Authors: Prodromos Sakaloglou Petros Bozidis Konstadina Kourou Charilaos Kostoulas Athanasia Gouni Eleni Tsaousi Despoina Koumpouli Sofia Argyropoulou Petros Oikonomidis Helen Peponi Ioannis Sarantaenas Eirini Christaki Ioannis Georgiou Konstantina Gartzonika

In early 2020, Greece was affected by the SARS-CoV-2 epidemic, and since then, the continuous emergence of fast-spreading variants has caused surges of new SARS-CoV-2 infections. In this study, we performed genomic, phylogenetic, and epidemiological analyses to investigate the SARS-CoV-2 epidemic in northwestern Greece. From March 2020 to February 2022, nasopharyngeal samples obtained from patients suspected to have COVID-19 were tested for SARS-CoV-2 detection. Complete SARS-CoV-2 genomic sequences were generated from selected positive samples. Northwestern Greece experienced four distinct waves of the epidemic following the first wave, which was mainly observed in Attica and other parts of Greece. The positivity index was rising throughout the pandemic waves in several geographical units, with the highest levels recorded in prominent tourist destinations characterized by high agricultural density. The phylogenetic analyses revealed 34 different lineages, with B.1, B.1.1, B.1.1.305, B.1.1.318, B.1.177, B.1.1.7, B.1.617.2, AY.43, and BA.1 being the most prevalent lineages in the region. Although multiple lineages were co-circulating, each pandemic wave was dominated by a different lineage. The SARS-CoV-2 epidemic in northwestern Greece was characterized by the successive introduction of new lineages, resulting in surges of new SARS-CoV-2 infections.

Acta Microbiologica Hellenica doi: 10.3390/amh69040025

Authors: Francesco Gambilonghi Valeria Fichera Vincenzo Sortino Patrizia Grassi Ausilia Desiree Collotta Marco Simone Vaccalluzzo Alfredo Pulvirenti Silvia Marino Martino Ruggieri Salvatore Castiglione Raffaele Falsaperla

The cycle threshold (Ct) value of PCR, used to detect SARS-CoV-2 viral load, has been associated with disease severity in adults, but few studies have examined these relationships in pediatric patients. The aim of this study was to evaluate the relationship between the Ct value at hospital admission and the duration of fever, length of hospital stay, and the need for medical interventions in pediatric patients with COVID-19. We conducted a retrospective study of 124 pediatric patients with a positive nasopharyngeal swab for SARS-CoV-2 between April 2020 and March 2022. A negative correlation was observed between the Ct value and the duration of fever (p = 0.012), with a similar trend for length of hospital stay (p = 0.25). A low Ct value was also associated with the development of MIS-C (p = 0.026) and the need for respiratory support and steroid therapy (p = 0.036). The Ct value may be useful in stratifying pediatric patients with COVID-19, helping to predict the duration of fever and hospital stay, as well as the need for medical interventions.

Acta Microbiologica Hellenica doi: 10.3390/amh69040024

Authors: Oyibo Joel Enupe Christiana Micah Umar Manbyen Philip Emmanuel Musa Victor Baba Oti Asif Khaliq

Biofilms are bacterial communities on surfaces within an extracellular matrix. Targeting biofilm-specific bacteria is crucial, and natural compounds with reported antibiofilm activity have garnered significant interest. The study evaluated the antibacterial and antibiofilm activity of Erythrina senegalensis leaf extract against multidrug-resistant (MDR) Gram-negative bacteria, including Salmonella Typhimurium, S. Typhi, S. Enteritidis, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The leaf extract was prepared using aqueous and ethanol solvents, and qualitative phytochemical screening revealed the presence of various bioactive compounds such as tannins, saponins, cardiac glycosides, flavonoids, terpenoids, alkaloids, anthraquinone, reducing sugar, and ketones. A Kirby–Bauer disc diffusion assay was performed to test the susceptibility of antibiotics, and the antibacterial efficacy of the aqueous and ethanol extracts of E. senegalensis was determined using the cup-plate method, while the antibiofilm activities were determined using the crystal violet titer-plate method. The aqueous and ethanol extracts of E. senegalensis revealed the presence of tannins, saponins, cardiac glycosides, flavonoids, terpenoids, alkaloids, anthraquinone, reducing sugar, and ketones. The study found that the Gram-negative bacteria isolates that were MDR were S. Typhimurium, S. Enteritidis, and P. aeruginosa, while K. pneumoniae was resistant to beta-lactam and fluoroquinolones, and S. Typhi was susceptible to all antibiotics tested. Statistically, susceptibility to antibiotics had an inverse, weak, and significant relationship with biofilm production (r = −0.453, −0.106, −0.124, −0.106, −0.018, n = 10, p < 0.05). The aqueous extract showed good biofilm inhibition against K. pneumoniae and P. aeruginosa, and poor biofilm inhibition against S. Enteritidis, while S. Typhimurium and S. Typhi exhibited no biofilm inhibition. The ethanol extract did not demonstrate any antibiofilm activity against the tested Gram-negative pathogens. The study suggests that the Gram-negative bacteria’s capacity to form biofilms is negatively associated with their antibiotic resistance phenotypes, and the aqueous extract of E. senegalensis exhibited moderate antibiofilm activity against K. pneumoniae, P. aeruginosa, and S. Enteritidis.

Acta Microbiologica Hellenica doi: 10.3390/amh69040023

Authors: Aimilios Pliatsikas Georgia Vrioni Joseph Papaparaskevas Constantinos Tsiamis Athanasios Tsakris

Tuberculosis has had a long-standing prevalence in Greece over the last century, going hand in hand with the country’s overall socioeconomic situation. The current study explores aspects of tuberculosis in Greece since the interwar period and up to the present. Apparently, ignorance of the nature of the disease coupled with false medical perceptions sealed the fate of patients while unwittingly influencing public opinion and making societies hostile toward patients. Such paradigms are of great and timeless value for the cohesion and functioning of societies, not excluding modern ones. Although the present-day situation in Greece is utterly different from that in the previous century, considering the limited number of cases and minimal impact of the disease, new challenges have emerged, such as the under-reporting of cases, the emergence of multidrug-resistant tuberculosis, latent tuberculosis or the management of large refugee flows in the Eastern Mediterranean involving citizens from countries with a high prevalence of the disease. On the other hand, the study of tuberculosis is nowadays more urgent than ever, given the global concerns regarding the future of the disease in the midst of the COVID-19 pandemic, which has put enormous pressure on national health systems.

Acta Microbiologica Hellenica doi: 10.3390/amh69040022

Authors: Ayodele T. Adesoji Osaro Mgbere Charles Darkoh

The United States Centers for Disease Control and Prevention (CDC) has categorized Clostridioides difficile infection (CDI) as a significant concern in extended-care facilities, hospitals, and outpatient clinics. However, little is known about CDI in low- and middle-income countries. This study determined CDI prevalence and impact in outpatient adults presenting with diarrhea in Nigeria. Toxigenic culture and PCR were used to detect and validate C. difficile. Prior antibiotic use, medical history, and demographic data were also obtained. Descriptive and inferential statistics were used for data analysis. The patient demographics were 35.48% (22/62) for the 18–24 years age group and 32.26% (20/62) for both the 25–30 years age group and the 31+ years group, with an average age of 29.7 years. Forty-eight percent of the patients (30/62) tested positive for CDI, and the prevalence increased with age. Most patients (86.67%, 52/60) reported moderate/severe cases of diarrhea and 67.7% had no knowledge of antibiotics. The results showed that 62.30% of the cases were hospitalized with the duration of diarrhea being significantly associated (r = 0.98, p ˂ 0.001) with the length of hospitalization. These results suggest that C. difficile is common among diarrhea patients in this population and that Nigerian hospitals’ infection prevention and control measures must include this pathogen.

Acta Microbiologica Hellenica doi: 10.3390/amh69040021

Authors: Luka Švitek Mihaela Zlosa Barbara Grubišić Kristina Kralik Nora Perić Bernarda Berišić Dubravka Lišnjić Sanja Mandić

Neutrophil gelatinase-associated lipocalin (NGAL) is a protein secreted by activated neutrophils and certain tissues. The aim of this study was to investigate the prognostic role of urinary neutrophil gelatinase-associated lipocalin (uNGAL) in hospitalized COVID-19 patients with regard to mortality. The prospective observational cohort study involved 86 hospitalized adult COVID-19 patients. Patients’ urine samples were collected upon admission and 48–72 h after admission. General anamnesis and clinical status information were obtained from medical records. Within 24 h of sample collection, urine aliquots were centrifuged, the supernatant was separated, and samples were frozen at −80 °C until uNGAL concentration measurement, which was performed within two years of sample collection. The patients were categorized into groups based on disease outcome (survived/deceased). Data analysis was performed to identify predictive factors and diagnostic indicators for the unfavorable outcome group using logistic regression and ROC curve methods. Logistic regression associated age, cardiomyopathy, invasive mechanical ventilation, and uNGAL concentration (follow-up sampling) with mortality. ROC analysis identified uNGAL concentration (follow-up sampling) as an indicator of mortality, with a cut-off value of >23.8 ng/mL. This study concludes that there is an association between disease outcome and uNGAL concentration in COVID-19 patients. However, understanding the dynamics of uNGAL concentration during COVID-19 remains limited, which is crucial for its effective clinical application.

Acta Microbiologica Hellenica doi: 10.3390/amh69040020

Authors: Teferi Degefa Mahlet Birehanu Demise Mulugeta Henok Ferede Endalkachew Girma Anberber Alemu Dassalegn Muleta Abebe Mengesha Aga Debebe Shimeket Dereje Nigussie Woldemichael Mirtneh Akalu Fanos Tadesse Woldemariyam

Newcastle disease, which affects poultry and is endemic in many nations across the world, is caused by Avian Paramyxovirus-1 (APMV-1). This experimental study was conducted from January to June 2021 at the National Veterinary Institute (NVI) to evaluate the virus viability and antibody titer of Newcastle disease vaccines (Hichner’s B1, Lasota, and ThermostableI2) stored at different temperature storage conditions. Chickens (12 treatment groups and 1 control group) were vaccinated and challenged with the virulent ND virus (0.5 × 106.5 embryonic lethal dose fifty (ELD50)). The immune responses (antibody titers) of chickens were evaluated using hemagglutination (HA) and hemagglutination inhibition (HI) assays. The Newcastle disease vaccines (Hachiner’s B1 (ND-HB1), ND-Lasota, and ND-Thermostable I2) stored at +4 °C HI-induced antibody titers of 151 (±103.3), 136 (±53.4), and 145 (±91) on day 14, respectively, whereas on day 21, they increased to 160 (±82) for ND-HB1 and 144 (±74.5) for ND-Lasota. ND-Thermostable I2 showed a decrement to 133 (±44.8). All three vaccines stored at different temperature storage conditions (+4, +23, and +30 °C) used in this experiment induced antibody titers greater than 128 on day 28 post-vaccination, except the Newcastle disease vaccine Thermostable I2 stored at +30 °C. The vaccines collected from private veterinary drugstores (customer vaccines Hachiner’s B1 and ND-Thermostable I2) used in this experiment induced very low antibody titers, less than 128 antibody titers, from days 14 to 21. Statistically significant induced mean antibody titers were observed for chickens that received vaccines stored at different temperature storage conditions for 72 h (p < 0.05), except for the ND-HB1 mean HI-induced antibody titer at days 7 and 28. Further, vaccine protection was confirmed by inoculation of both the vaccinated (treatment groups) and control groups by the virulent ND virus, where the control group started dying three days post-challenge but all chicks that received the vaccines survived. Overall, this study showed the impact of temperature storage conditions on the antibody titer and their effect on the titer of the viable virus in the vaccine, and thereby its protective capacity, warranting appropriate cold chain management of the vaccines along the value chain.

Acta Microbiologica Hellenica doi: 10.3390/amh69030019

Authors: Tahne Vongsavath Magnus Chun Kyaw Min Tun Vignan Manne

Hepatic abscesses (HAs) are suppurative cavities caused by the infiltration of liver parenchyma by microbes. The etiology of HAs can include biliary disease, intra-abdominal infections, bile duct ischemia following pancreaticoduodenectomy, liver transplantation, and rarely septicemia, among others. While HA of a bacterial origin is rare, intra-abdominal biliary infections can be seen after appendicitis or proctitis. Empiric treatment generally involves antibiotic coverage and percutaneous drainage. Due to a high health care association, Clostridioides difficile infection (CDI) is becoming more frequent and has increasing antibiotic resistance. While generally limited to the gastrointestinal tract, extra intestinal CDIs are generally related to bacteremia, and related HAs are even rarer, with their prognostic courses not well described. A literature search was performed evaluating case reports and manuscripts relating to CDI-related HA. Articles with relevant information were analyzed for quality. Those fitting predetermined selection criteria and the level of evidence were included in this study. While most affected patients reported recent hospitalization and significant comorbidities, some of them reported no apparent risk factors at all. While all included individuals had HA, only 33.3% had CD-related bacteremia. Treatment of HA was managed with drainage as well as antibiotics and was generally successful, with one death. As CDI becomes more prevalent, studies such as this will be needed to address the management of associated HA.

Acta Microbiologica Hellenica doi: 10.3390/amh69030018

Authors: Marc Ohlhausen Christopher D. Conrady

Gene therapy is an emerging field of medicine that can target and treat previously untreatable blinding or lethal diseases. Within the field of ophthalmology, gene therapy has emerged to treat retinal degenerative disorders, but its exact role is in its infancy. While this exciting frontier is rapidly expanding, these typically viral-based gene therapy vectors trigger a host immune response. Thus, a better understanding of the host immune response to gene therapies is critical, in that harnessing immunity to these vectors may improve treatment efficacy and reduce the risk of vision loss from inflammation. As such, we will discuss innate and adaptive immunity to gene therapy vectors, and avenues through which this response may be harnessed to improve visual outcomes.

Acta Microbiologica Hellenica doi: 10.3390/amh69030017

Authors: Alfredo A. Hinay Nelyn Mae T. Cadotdot Marilou V. Tablizo Aprilyn F. Francisco

The search for effective inhibitors of HIV-1 replication remains a critical research area of research in virology and immunology. Natural products have emerged as promising candidates for antiviral therapies. In the present study, we assessed the potential inhibitory activity of Philippine crocodile serum at both pre- and post-infection stages of the HIV-1 replication cycle. Freshly collected crocodile serum samples were used in a cell culture-based assay with peripheral blood mononuclear cells. HIV-1 reverse transcriptase activity in the treated cell culture system was assessed using colorimetric enzyme immunoassay. The crocodile serum at 0.5% and 0.25% vol/vol concentrations showed an inhibitory activity against HIV-1 replication both in pre-infection interactions (68.61 ± 1.67% and 69.95 ± 2.24%, respectively) and post-infection interactions (65.68 ± 2.93% and 69.92 ± 0.45%, respective). These findings suggest that Philippine crocodile serum may have potential as a natural inhibitor of HIV-1 replication and warrant further investigation into its therapeutic use.

Acta Microbiologica Hellenica doi: 10.3390/amh69030016

Authors: Ahmed Elfadadny Rokaia F. Ragab Manar A. Abou Shehata Medhat R. Elfadadny Ahmed Farag Ayman H. Abd El-Aziz Hazim O. Khalifa

Bacteriophages, or phages, are microscopic viruses that specifically infect and replicate within bacterial hosts. Their unique ability to target and control bacterial populations makes them valuable tools with applications ranging from human medicine and agriculture and environmental management to biotechnology. In this comprehensive review, we explore the diverse and promising medical and non-medical applications of bacteriophages, highlighting their pivotal role across various niches. From safeguarding food production through pathogen control to their innovative utilization in wastewater treatment, bacteriophages prove to be versatile agents. To achieve applications of phages on a larger scale, it is necessary to make the legal framework more suitable and flexible, create special approval programs (e.g., for novel antimicrobial drugs), and promote targeted research and development activities on phages. Additionally, a more intensive exchange between academia, industry, regulatory authorities, and stakeholders in the health system should be pursued.

Acta Microbiologica Hellenica doi: 10.3390/amh69030015

Authors: Henry Sutanto

Malaria remains a leading cause of morbidity and mortality worldwide, with significant efforts directed towards developing effective vaccines to curb its impact. The One Health concept, recognizing the interconnectedness of human, animal, and environmental health, offers a comprehensive approach to understanding and combating this disease. This review examines the development of malaria vaccine through the lens of the One Health framework, highlighting the integration of human, vector, and environmental factors in the fight against malaria. We discuss the current landscape of malaria vaccine development, including the deployment of the RTS,S/AS01 vaccine and the progress of other candidates such as the R21/Matrix-M and PfSPZ vaccine. The challenges posed by the complex lifecycle of the malaria parasite, its genetic diversity, and the environmental factors influencing transmission are explored. This review also discusses emerging technologies and innovations that could enhance vaccine efficacy and delivery. Additionally, we consider ethical, social, and economic factors critical to the successful implementation of vaccination programs. In concluding, this review underscores the importance of adopting a One Health approach to malaria vaccine development, advocating for integrated efforts to address the multifaceted challenges of malaria control and eradication.

Acta Microbiologica Hellenica doi: 10.3390/amh69030014

Authors: Yang Xu Xuhui Liang Chang-Gu Hyun

A potential biocontrol agent for American foulbrood (AFB), the Paenibacillus bacteriophage phJNUCC32, was isolated from Baengnokdam in Halla Mountain. This study aimed to investigate its genomic characteristics through whole-genome sequencing. The genome of phJNUCC32 was found to be 62,871 base pairs in length, with a G + C content of 51.98%. Phylogenetic analysis classified phJNUCC32 within the unclassified Caudoviricetes bacteriophage category. The genome prediction confirmed the absence of virulence factors and antibiotic-resistance genes, ensuring its genetic safety. A total of 63 coding DNA sequences were identified, revealing a modular arrangement. Notably, the annotation of gene function indicates that phJNUCC32 harbors the holin/lysin system, suggesting significant potential for controlling bacterial infections in AFB and agriculture.

Acta Microbiologica Hellenica doi: 10.3390/amh69030013

Authors: Athanasios Tsakris

The COVID-19 pandemic has challenged the resilience of public health sectors worldwide [...]

Acta Microbiologica Hellenica doi: 10.3390/amh69020012

Authors: Gabor Kiss Daniel Corken Rebecca Hall Alhassan Ibrahim Salissou Moutari Frank Kee Gillian Armstrong Declan Bradley Maeve Middleton Lynsey Patterson Felicity Lamrock

The number of confirmed positive tests of various sexually transmitted infections has grown recently in the United Kingdom. The objective of this study is to propose a deterministic compartmental model to investigate gonorrhoea spread in Northern Ireland between 2012 and 2022. The differential equation based model includes both symptomatic and asymptomatic spread, spontaneous recovery and treatment compartments. After fitting our model to the monthly number of new positive tests, we found that the basic reproduction number is approximately 1.0030. In addition, we derive the endemic equilibrium of the model, which exists if and only if R0>1. The sensitivity analyses of the basic reproduction number and the endemic values of the compartments of treated individuals indicate that infection spreading time can have a significant impact on gonorrhoea spread.

Acta Microbiologica Hellenica doi: 10.3390/amh69020011

Authors: Eleni Makri Ekatherina Charvalos Elisavet Stavropoulou Constantina Skanavis Areti Lagiou Anastasia Barbounis

Vaccination has emerged as the most effective tool in the battle against COVID-19. To optimize vaccination protocols, a deeper understanding of the immune response to vaccination, including influential factors and its duration, is essential. This study aimed to assess the humoral response in vaccinated individuals with or without prior SARS-CoV-2 infection. A prospective observational study was conducted across 14 private healthcare structures in Greece. Anti-spike IgG titers were measured at different timepoints following the initial vaccination and booster doses of the BNT162b2, mRNA-1273, ChAdOx1 nCoV-19, and Ad26.COV2.S vaccines. A total of 505 participants were included in the first phase, evaluating the humoral response after the initial vaccination, and 311 participants were involved in the second phase, assessing the effects of booster vaccination. All vaccines elicited high anti-S IgG titers initially, followed by a subsequent decline that was addressed by the booster vaccination. The humoral response was sustained up to one year after the booster vaccination. mRNA vaccines induced higher anti-S IgG titers compared to vector vaccines, with mRNA-1273 eliciting higher titers than BNT162b2. Vaccination resulted in higher antibody titers than natural infection alone; however, convalescent patients who received vaccination had significantly higher anti-S IgG titers compared to those who received the booster vaccine without previous SARS-CoV-2 infection. Lower antibody titers were observed in men and older patients (>51.5 years old), as well as smokers, although the decline rate was lower in these subgroups. These results underscore the importance of booster doses and reveal the potential influence of age, gender, smoking habits, and vaccine type on varying humoral responses. Long-term monitoring of antibody persistence, evaluation of cellular immune responses, and assessment of vaccine efficacy against emerging variants should be considered to enhance our understanding of immunity dynamics and inform vaccine development and deployment strategies.

Acta Microbiologica Hellenica doi: 10.3390/amh69020010

Authors: Georgia Vrioni Theodoros A. Peppas

Our intention was to trace the origins of names that every microbiologist comes to pronounce or write down in her/his daily practice and, particularly, to elucidate the etymological debt of this medical field to the two great languages of classical antiquity, Greek and Latin. According to the system of binomial nomenclature established by Linnaeus in the 1750s to give a unique name to each species, consisting of two terms, the name of the genus and the name of the species, combinations were based on Greek and Latin. The two major cocci consist of a literally classical example. Streptococci, named so by Bilroth from the Greek word “στρεπτόν—strepton” (necklace), and staphylococci, baptised by Ogston from “staphyli—σταφύλι” (grape), were both so named due to their appearance under microscopy. Two well-known species of these genera bear Latin names denoting colour, greenish for S. viridans and golden for S. aureus. Other bacteria display the discovering scientist like, E. coli for Escherich, Brucella from Bruce, or Pasteurella from Louis Pasteur. Similar pathways also exist for viruses, even back to Hippocrates, like Herpesviruses from “έρπης—herpes” (creeping) or Arenaviruses from “arena—sand”, and fungi, as mycology itself originates from “μύκης—myces”, Greek for fungus, and Aspergillus from the verb “aspergo” (to sprinkle).

Acta Microbiologica Hellenica doi: 10.3390/amh69020009

Authors: Amalia Papanikolopoulou Louisa Vini Athina Stoupis Dimitra Kalimeri Anastasia Pangalis Genovefa Chronopoulou Nikos Pantazis Panagiotis Gargalianos-Kakolyris Maria Kantzanou

Carbapenem-resistant Klebsiella pneumoniae (CRKP) remains a significant public health threat, given the associated increased healthcare burden and mortality rate. The objective of the current study was to investigate the association between the incidence of CRKP bacteremia, antibiotic consumption, and infection control measures in a tertiary-care hospital spanning the years 2013–2018. The analyzed indices included the incidence of CRKP bacteremia, antibiotic consumption, the use of hand hygiene solutions, and isolation rates of multidrug-resistant (MDR) carriers. In the total hospital, the incidence of CRKP bacteremia exhibited an absolute decrease during the study period, although this decrease did not reach statistical significance. Antibiotics used to treat CRKP infections, including carbapenems, colistin, tigecycline, and fosfomycin, as well as all classes of antibiotics, correlated positively with an increased incidence of CRKP bacteremia. On the contrary, increased use of scrub disinfectant solutions correlated negatively with a decreased incidence of CRKP bacteremia (IRR: 0.74, 95%CI: 0.59–0.93, p-value: 0.008) in the Adults ICU. Additionally, increased isolation rates of MDR carrier patients correlated negatively with a decreased incidence of CRKP bacteremia (IRR: 0.35, 95%CI: 0.13–0.97, p-value: 0.044). In conclusion, the implementation of multimodal infection control measures in our hospital contributed to the containment of CRKP, particularly in specific hospital sectors. However, the study suggests the need for additional strategies to overcome the endemic plateau.

Acta Microbiologica Hellenica doi: 10.3390/amh69020008

Authors: Mehdi Aghamohammadi Samad Ghodrati Milad Etemadi Sh Mohammad Soroush Sehat Javad Alizargar

The COVID-19 pandemic has led to an unprecedented surge in respiratory illness cases worldwide. Although uncommon, pulmonary cavitation has been reported as a potential complication of COVID-19. This case series report describes four cases of COVID-19 patients with lung cavities, highlighting the various causes and clinical manifestations of this complication, and a review of the literature on the presence of lung cavities in COVID-19 patients. In two cases, the cavities were most likely due to secondary bacterial superinfections, with one case being complicated by multi-drug-resistant bacteria. Another case developed cavities secondary to a fungal infection, while the third case was directly caused by SARS-CoV-2 invasion in the lungs. The presence of cavities with or without air-fluid level or pneumothorax in COVID-19 patients should be considered as a potential complication of this infection, especially in those with respiratory symptoms. Physicians should remain vigilant for the development of pulmonary cavitation in COVID-19 patients, particularly those receiving high doses of steroids. Additionally, spontaneous pneumothorax should be considered an alarming sign in COVID-19 patients.

Acta Microbiologica Hellenica doi: 10.3390/amh69020007

Authors: Diamantis Klimentidis Georgios Pappas

Urinary tract infections (UTIs) cause a significant infectious burden in the community and demand a coordinated approach from all first-line health professionals. Uncomplicated UTIs refer to infections in non-pregnant females without any underlying localized or generalized pathology, diagnosed through history by the presence of specific local symptoms and in the absence of systemic ones like fever. Uncomplicated UTIs are usually caused by Escherichia coli species; thus, empirical antibiotic treatment can be immediately initiated. A percentage of patients can experience a resolution of symptoms without therapy; however, this “wait and observe” approach is supported only by the relevant British guidelines. There are limited quality studies in the literature on adjuvant treatment options; these can include BNO 145, a phytotherapeutic medicine, and XHP, a medical technology product. Despite being licensed by the European Medicines Agency on the basis of traditional use, there is inadequate support in the medical literature for the use of cranberry extracts and Arctostaphylos uva-ursi extracts. The use of antibiotics is associated with higher response rates and urine culture sterilization as well as lower recurrence/relapse rates; on the other hand, side effect rates are also higher. In choosing the proper empirical antibiotic therapy, one has to take into account individual patient characteristics and community resistance patterns as well as the antimicrobial resistance pressure exerted by the wide use of a specific antibiotic. There is a need for a common framework through which all frontline health practitioners should operate when faced with a case of uncomplicated UTI. In Greece, there are three different guidelines for UTI treatment, developed by the Ministry of Health, the National Organization for Medicines, and the Hellenic Society for Infectious Diseases. The authors of the present study aim at synthesizing these guidelines as well as relevant guidelines from international scientific or other national regulatory organizations while taking into account local resistance patterns. The authors propose the first-line use of either fosfomycin, nitrofurantoin, or pivmecillinam. The use of trimethoprim/sulfamethoxazole is discouraged due to increased resistance of Greek community E. coli isolates. Fluoroquinolone use should be avoided due to high E. coli community resistance (exceeding 20% for Greece), along with their unfavorable benefit/side effect balance in uncomplicated UTIs, as well as the overall community resistance pressure exerted by their use. A 5-day regimen remains superior to a 3-day one; the latter may be suitable for certain, not yet adequately characterized, patients.

Acta Microbiologica Hellenica doi: 10.3390/amh69010006

Authors: Spyridon-Andreas Papatheodorou Dimitra Houhoula Sotirios Magoulas Andreas G. Tsantes Efstathia Tsakali Simen Akkermans Jan Van Impe Panagiotis Halvatsiotis Argyrios E. Tsantes

Traditional methods of detecting foodborne pathogens take several days to produce the required results. Furthermore, various molecular techniques (e.g., PCR) that also produce reliable results in the detection of pathogenic bacteria have been introduced, but the cost–time ratio required does not allow them to be considered a substantial solution to this specific problem. Three-dimensional (3D) printing technology provides the ability to design and manufacture microfluidic analytical devices using conventional 3D printers, which, in combination with colorimetric loop-mediated isothermal amplification (LAMP), may further simplify the process. The overall reduction in time and cost may provide the opportunity to upscale this diagnostic modality. Moreover, unlike most microfluidic analytical devices, this technique is simpler and more user-friendly, as it does not require any expertise or additional equipment apart from a conventional oven. A 3D-printed microfluidic analytical device in combination with LAMP was developed and tested for the simultaneous detection of foodborne pathogens in food samples. A total of 150 commercial food specimens (50 milk, 50 chicken, 50 lettuce samples) were analyzed for possible contamination with Salmonella typhimurium, Listeria monocytogenes and Escherichia coli. The 3D-printed microfluidic device was 100% precise for both negative (80 samples) and positive samples (7 samples were positive for S. typhimurium, 28 for L. monocytogenes, and 35 for E. coli) for all pathogens. Overall, the amount of data analyzed led to a high level of confidence in the precision of this device. As such, this new 3D device in combination with LAMP provides a precise detection method for food pathogens with a low detection limit.

Acta Microbiologica Hellenica doi: 10.3390/amh69010005

Authors: John Ahenkorah Stephen Opoku-Nyarko Kevin Kofi Adutwum-Ofosu Bismarck Hottor Joana Twasam Emmanuel Afutu Clement Nyadroh Fleischer C. N. Kotey Eric S. Donkor Nicholas T. K. D. Dayie Edem M. A. Tette Patience B. Tetteh-Quarcoo

Retroviral and hepatitis B infections can be potential threats to foetomaternal health through inducing distortions of the architecture and structure of the placenta. Improved insights into the effects of these infections on placental morphology would be integral to our understanding of maternal and neonatal health. Aim: To histomorphologically and stereologically investigate selected placental structures in virus-infected (HIV [human immunodeficiency virus] and hepatitis B virus [HBV]) and uninfected women at term. Method: This cross-sectional study involved the screening of 237 placentae collected at term (38 ± 2 weeks) from the maternity delivery units and surgical theatres of the LEKMA and Weija/Gbawe Municipal Hospitals in Accra. Venous blood samples from the umbilical vein and placenta basal plate blood were screened for HIV, HBV, and hepatitis C virus (HCV) using serological test kits (RDT). A total of 34 placentae were selected, comprising 20 cases and 14 controls that were gestational age-matched. Using stereology and a systematic random sampling technique with test point and intersection counting of photomicrographs, the mean volume densities of syncytial knots, syncytial denudations, foetal capillaries, and intervillous spaces of the placentae were estimated on a total of 2720 photomicrographs. Results: On stereological assessment, there was a statistically significant difference in the mean volume densities of syncytial knots (HIV-infected = 0.562 ± 0.115, HBV-infected = 0.516 ± 0.090, control group = 0.171 ± 0.018, p = 0.001), syncytial denudations (HIV-infected = 0.121 ± 0.022, HBV-infected = 0.111 ± 0.016, control group = 0.051 ± 0.00, p = 0.004), and foetal capillaries (HIV-infected = 0.725 ± 0.152, HBV-infected = 0.902 ± 0.078, control group = 0.451 ± 0.064, p = 0.006) among the different groups of placentae (control) at term. A statistically significant decrease in intervillous space (p = 0.022) was recorded in HBV-infected placentae compared to the control (from 15.450 ± 1.075 to 11.32 ± 0.952). Conclusion: Placental viral infections might lead to significant increases in syncytial knots, foetal capillaries, and syncytial denuded areas of the chorionic villi and a significant decrease in intervillous spaces. This finding could signify evidence of advanced gestation, placental malperfusion, hypermaturity of the placenta, and a possible vertical transmission of the viral antigen to the foetus, which may be crucial in understanding perinatal outcomes.

Acta Microbiologica Hellenica doi: 10.3390/amh69010004

Authors: Panagiota Foteinidou Maria Exindari Dimitrios Chatzidimitriou Georgia Gioula

The endometrial cavity was considered sterile until the second half of the 20th century. Through modern technological advances and the sequencing of the bacterial 16S rRNA gene, it was proven that the area possesses its own unique microbiome, which can be categorised into two types, Lactobacillus-dominant (LD, with a Lactobacillus spp. abundance percentage greater than 90%) and non-Lactobacillus-dominant (non-LD, with a Lactobacillus spp. abundance percentage smaller than 90%), with other species like Bifidobacterium, Gardnerella, Prevotella, and Streptococcus also being prominent. The aim of this study was to investigate the possible correlation of the endometrial microbiome to female infertility, through the identification and appraisal of studies published in the databases PubMed, Web of Science, and Scopus. Moreover, 12 studies met the research criteria, including the analysis of endometrial fluid or tissue samples from infertile women through PCR, culturomics-based, or NGS methods. According to most of these studies, a eubiotic LD-type microbiome seems to be best for maximising endometrial receptivity and pregnancy chances, whereas a dysbiotic non-LD-type microbiome, with increased α-diversity and a higher number of pathogens, has a harmful effect. There were few studies that presented contradictory results without, however, a satisfactory explanation. Thus, more time and a greater number of studies are required to clarify contradictions and achieve more certain results.

Acta Microbiologica Hellenica doi: 10.3390/amh69010003

Authors: Shan Chen Yuanzhao Ding

Biofilms exert a profound impact on various facets of human life. Positive instances of biofilm usage involve their capacity to immobilize pollutants such as heavy metals, while adverse cases result in infections like urinary tract infections. Therefore, the study of biofilm engineering emerges as crucial. Employing a bibliographic research approach, this paper delves into biofilm engineering, identifying key species like Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, among others. The investigation also unveils major research subjects and corresponding institutions dedicated to biofilm research. A comprehensive understanding of biofilm engineering holds profound implications for advancing knowledge in this domain.

Acta Microbiologica Hellenica doi: 10.3390/amh69010002

Authors: Maria Fotiou

Acta Microbiologica Hellenica was launched in 1956 as the official bimonthly journal of the Hellenic Society for Microbiology, aiming to provide a constant educational platform for biopathologists, clinical microbiologists, and every scientist involved in laboratory and clinical medicine [...]

Acta Microbiologica Hellenica doi: 10.3390/amh69010001

Authors: Athanasios Tsakris

The first issue of Acta Microbiologica Hellenica, a bimonthly journal in Greek, was published in 1956 by the Hellenic Society for Microbiology, one of the oldest and most respected scientific Greek medical societies, founded in 1932 [...]