Acta Microbiol. Hell., Volume 70, Issue 2 (June 2025) – 8 articles

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article