Search Results (752)

Tuberculosis (TB) is an ancient and re-emerging granulomatous infectious disease that continues to challenge public health. Early diagnosis and prompt effective treatment are crucial for preventing disease progression and reducing both morbidity and mortality. These steps play a vital role in infection control and in lowering death rates at both individual and population levels. Although diagnostic methods have improved sufficiently in recent decades, TB can still present with ambiguous laboratory and imaging features. This ambiguity can lead to diagnostic pitfalls and potentially disastrous outcomes due to delayed diagnosis. In this article, we present a case of TB that was difficult to diagnose. The disease had invaded the mediastinum, right atrium, right coronary artery, and inferior vena cava (IVC), resulting in Budd–Chiari syndrome. This rare presentation created clinical, laboratory, and radiological confusion, resulting in a diagnostic dilemma that ultimately led to open cardiac surgery. The patient initially presented with progressive shortness of breath on exertion and fatigue, which suggested possible heart disease. This suspicion was reinforced by computed tomography (CT) imaging, which showed infiltrative mass lesions predominantly in the right side of the heart, invading the right coronary artery and IVC, with imaging features mimicking angiosarcoma. Although laboratory findings revealed an exudative effusion with lymphocyte predominance and elevated adenosine deaminase (ADA), the Gram stain was negative for bacteria, and an acid-fast bacilli (AFB) smear was also negative. These findings contributed to diagnostic uncertainty and delayed the confirmation of TB. Open surgery with excisional biopsy and histopathological analysis ultimately confirmed TB. We conclude that TB should not be ruled out solely based on negative Mycobacterium bacteria in pericardial effusion or AFB smear. TB can mimic aggressive tumors such as angiosarcoma or lymphoma with invasion of the surrounding tissues and blood vessels. Awareness of the clinical presentation, imaging findings, and potential diagnostic pitfalls of TB is essential, especially in endemic regions. Full article

Cystic fibrosis produces viscous mucus in the lung that increases bacterial invasion, causing persistent infections and subsequent inflammation. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most common infections in cystic fibrosis patients that are resistant to antibiotics. One antibiotic approved to treat these infections is levofloxacin (LVX), which functions to inhibit bacterial replication but can be further developed into tailorable particles. Nanoparticles are an emerging inhaled therapy due to enhanced targeting and delivery. The extracellular matrix (ECM) has been shown to possess pro-regenerative and non-toxic properties in vitro, making it a promising delivery agent. The combination of LVX and ECM formed into nanoparticles may overcome barriers to lung delivery to effectively treat cystic fibrosis bacterial infections. Our goal is to advance CF care by providing a combined treatment option that has the potential to address both bacterial infections and lung damage. Two hybrid formulations of a 10:1 and 1:1 ratio of LVX to ECM have shown neutral surface charges and an average size of ~525 nm and ~300 nm, respectively. The neutral charge and size of the particles may suggest their ability to attract toward and penetrate through the mucus barrier in order to target the bacteria. The NPs have also been shown to slow the drug dissolution, are non-toxic to human airway epithelial cells, and are effective in inhibiting Pseudomonas aeruginosa and Staphylococcus aureus. LVX-ECM NPs may be an effective treatment for pulmonary CF bacterial treatments. Full article

The role of rhizosphere bacteria in facilitating plant invasion is increasingly acknowledged, yet the influence of specific microbial functional traits remains insufficiently understood. This study addresses this gap by isolating two bacterial strains, Bacillus sp. ScRB44 and Pseudomonas sp. ScRB22, from the rhizosphere of the invasive weed Solidago canadensis. We assessed their nitrogen utilization capacity and indoleacetic acid (IAA) production capabilities to evaluate their ecological functions. Our three-stage experimental design encompassed strain promotion, nutrient stress, and competition phases. Bacillus sp. ScRB44 demonstrated robust IAA production and significantly improved the nitrogen utilization efficiency, significantly enhancing S. canadensis growth, especially under nutrient-poor conditions, and promoting a shift in biomass allocation toward the roots, thereby conferring a competitive advantage over native species. Conversely, Pseudomonas sp. ScRB22 exhibited limited functional activity and a negligible impact on plant performance. These findings underscore that the ecological impact of rhizosphere bacteria on invasive weeds is closely linked to their specific growth-promoting functions. By enhancing stress adaptation and optimizing resource allocation, certain microorganisms may facilitate the establishment of invasive weeds in adverse environments. This study highlights the significance of microbial functional traits in invasion ecology and suggests novel approaches for microbiome-based invasive weed management, with potential applications in agricultural soil health improvement and ecological restoration. Full article

Background/Objectives: The main objective of the study is to assess the clinical utility of microbial cell-free DNA (mcfDNA) in neutropenic patients diagnosed with acute myeloid leukemia (AML) undergoing chemotherapy in the outpatient setting. Neutropenia is a common complication in this patient cohort and enhances the risk of fatal opportunistic bacterial and fungal infections. Accurate and timely diagnosis of these infections in outpatient asymptomatic individuals is critical. Methods: Fourteen patients were studied in this prospective observational case series. Traditional blood cultures (BCs) were obtained when clinically indicated and blood samples were collected for plasma mcfDNA metagenomic sequencing up to two times a week at outpatient oncology appointments. Results were compared in identifying potential infectious agents. Results: BCs identified pathogens in only two patients, despite several cases where infection was suspected. In contrast, mcfDNA testing detected pathogens in 11 of the 14 patients, including bacteria, such as Staphylococcus aureus, and invasive fungi, such as Candida and Aspergillus species, and Pneumocystis jirovecii. Conclusions: In the outpatient setting, mcfDNA surveillance offers a more reliable method for detecting pathogens. This approach identified actionable microbiologic results in immunocompromised individuals who did not meet standard clinical criteria for suspicion of infection. Further research is required to confirm the potential of mcfDNA surveillance in an outpatient setting to guide more accurate treatment decisions, reduce extensive clinical investigations, and improve neutropenic patient outcomes. Full article

Bloodstream infections are a significant cause of morbidity and mortality among hemodialysis patients. These infections primarily involve Gram-positive bacteria and, less frequently, Gram-negative bacilli. Raoultella ornithinolytica is a Gram-negative bacillus which is known to be a rare opportunistic pathogen. It is found only occasionally in human infections; however, it has been noted as an emerging pathogen. Sepsis caused by this microorganism is very rare. A few cases have been reported among immunocompromised patients or those undergoing invasive procedures. Cases involving urinary catheters or port catheters have also been reported, as well as a single case of a patient on peritoneal dialysis. Here, we present a novel case of Raoultella ornithinolytica bloodstream infection in a patient with chronic renal failure undergoing hemodialysis who was successfully treated. We discuss the microbiology and clinical features of such infections, and consider aspects of treatment. Full article

Background: Splenectomy remains necessary in selected oncologic and hematologic indications but is associated with significant postoperative morbidity and mortality. The data on outcomes in this high-risk population remain limited, particularly in mixed cohorts. Methods: We conducted a retrospective cohort study including all patients undergoing splenectomy for oncologic or hematologic causes between 2009 and 2022 at a cancer referral center. The primary outcomes were the occurrence of major complications at day 90 and the 1-year all-cause mortality. Multivariate logistic regression was used to identify independent predictors. Results: Among the 8503 ICU admissions from surgical wards, 204 splenectomies were performed; 179 patients were analyzed. The median age was 64 years, and 100 patients (55.9%) were female. Splenectomy was performed for hematologic malignancies in 76 cases (42.5%) and for oncologic causes in 103 cases (57.5%). Laparotomy was used in 154 cases (86.0%), and metastasectomy was performed in 54 patients (30.2%). At day 90, 86 patients (48.0%) developed a major complication: 12 deaths (6.7%), 44 surgical complications (24.6%), and 71 episodes of sepsis (39.7%). In a multivariate analysis, weight loss (OR 3.39, 95% CI [1.32–8.70], p = 0.011), laparotomy (OR 4.38 [1.09–17.60], p = 0.038), and a higher SAPS II score (OR 1.08 per point [1.03–1.13], p = 0.003) were associated with complications, while metastasectomy was protective (OR 0.23 [0.08–0.67], p = 0.007). At one year, the mortality reached 22.4%. Independent predictors of death were sepsis at one year (OR 5.04, 95% CI [1.30–25.96], p = 0.029), the Charlson Comorbidity Index (OR 1.30 per point, 95% CI [1.04–1.68], p = 0.030), invasive mechanical ventilation (OR 14.94, 95% CI [2.83–118.93], p = 0.003), and a performance status >1 (OR 7.84, 95% CI [2.38–27.75], p < 0.001). Encapsulated bacteria were not isolated; sepsis was mainly due to Gram-negative and enterococcal organisms. Conclusions: Splenectomy in onco-hematologic patients is associated with high rates of sepsis and mortality. In addition to surgical factors, frailty, immune status, and infection independently contribute to the patients’ outcomes. These results support risk-adapted perioperative strategies and long-term infectious surveillance in immunocompromised patients. Full article

A key feature that differentiates Gram-positive and Gram-negative bacteria is the outer membrane, an asymmetric membrane composed of lipopolysaccharides, phospholipids, lipoproteins and integral proteins, including the outer-membrane proteins (OMPs). By being in direct contact with the extracellular milieu, the outer membrane and OMPs participate in multiple functions in Gram-negative bacteria, including controlling nutrient and molecule access to the cytoplasm, membrane vesicle formation and resistance to environmental stresses. OMPs have a characteristic barrel shape formed by antiparallel β-strands, with or without channels that allow diffusion of substrates through the outer membrane. The marine bacterium Vibrio cholerae is responsible for non-invasive gastroenteritis and cholera disease by consumption of contaminated water or food. Its OMPs, besides having a porin function, contribute to resistance to osmotic pressure and antimicrobial agents, intracellular signaling, adhesion to host cells and biofilm formation, amongst other functions. In this review, in addition to quickly reviewing the general structure of the outer membrane, the OMPs and how they reach the outer membrane, the functions attributed to these proteins are compiled. The mechanisms used by each of the described OMP to accomplish these functions in the marine pathogenic bacterium V. cholerae are discussed. Potential clinical and bioengineering applications of OMPs, such as diagnostic tools, vaccine development, and targeted antimicrobial or anti-virulence strategies are presented. What is known about the OMPs of V. cholerae is presented below. Full article

The lung microbiota is integral to maintaining microenvironmental homeostasis, influencing immune regulation, host defense against pathogens, and overall respiratory health. The dynamic interplay among the lung microbiota emphasizes their significance in shaping the respiratory milieu and potential impact on diverse pulmonary affections. This investigation aimed to identify the effects of invasive mechanical ventilation on the lung microbiome. Materials and Methods: A systematic review was conducted with registration number CRD42023461618, based on a search of PubMed, SCOPUS, and Web of Science databases, in line with the PRISMA guidelines. To achieve this, “(mechanical ventilation) AND (microbiota)” was used as the search term, replicable across all databases. The closing date of the search was 12 March 2025, and the evidence was scored using the MINORS scale. Results: A total of 16 studies were included, with patients aged 13.6 months to 76 years, predominantly male (64.2%). Common ICU admission diagnoses requiring invasive mechanical ventilation (IMV) included pneumonia, acute respiratory failure, and COVID-19. IMV was associated with reduced lung microbiota diversity and an increased prevalence of pathogenic bacteria, including Prevotella, Streptococcus, Staphylococcus, Pseudomonas, and Acinetobacter. The most frequently used antibiotics were cephalosporins, aminoglycosides, and penicillins. IMV-induced pulmonary dysbiosis correlated with higher infection risk and mortality, particularly in pneumonia and COVID-19 cases. Factors such as antimicrobial therapy, enteral nutrition, and systemic inflammation contributed to these alterations. Conclusions: Invasive mechanical ventilation has been associated with the development of alterations in the respiratory microbiome, resulting in reduced diversity of lung microorganisms. Full article

Background/Objectives: Polycystic ovary syndrome (PCOS) is one of the most frequently diagnosed endocrine and metabolic disorders in women of reproductive age before menopause. It is associated with excess androgens and ovarian dysfunction, reduced fertility, the presence of obstetric disorders, but also metabolic disorders, and, among others, insulin resistance, obesity and type II diabetes. Its close relationship with changes in the diversity of the vaginal microbiome, vaginal inflammation and changes in the vaginal microenvironment, which can pave the way for pathogenic microorganisms, is emphasized. Methods: The research in the presented paper focuses on a group of women with PCOS (n = 490) of reproductive age (26–43 years), in whom the frequency of infections of the reproductive system caused by atypical pathogens, Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma spp., were analyzed, and then the immune system response was assessed in terms of the level of serum proinflammatory cytokines, IL-1β, IL-6 and TNF-α. Results: Our results showed a 40% infection rate in the studied group of patients with PCOS, with C. trachomatis being the most common pathogen (17.7%), followed by Ureaplasma spp. (10%) and M. hominis (4.9%). In some cases, co-infections such as Mycoplasma and Ureaplasma were also observed in 3.1% or all three atypical bacteria, M. hominis, Ureaplasma spp. and C. trachomatis, in 4.3% of patients with PCOS. In our study, in women with PCOS and confirmed infection with any atypical pathogen (n = 196), we analyzed the levels of proinflammatory cytokines, IL-1 β a, IL-6 and TNF-α. The results were compared with a control group (control group A) consisting of patients with the same underlying disease, i.e., PCOS (n = 39), who did not experience infection with atypical pathogens or symptoms of gynecological infection. Additionally, a control group B (n = 28) consisting of healthy women (without PCOS and without infection) was introduced. The results regarding the levels of cytokines studied in this work (IL-1β, IL-6, TNF-α) may suggest that the presence of intracellular C. trachomatis in the infection will play a dominant role in the immune system response. In the infections with atypical pathogens analyzed in this study in patients with PCOS, no characteristic clinical features were observed, apart from indications in the form of an increase in the number of leukocytes in the assessment of the vaginal biocenosis, suggesting cervicitis and reported reproductive failure or lower abdominal pain. An additional problem is the inability to detect the presence of atypical pathogens in routine microbiological tests; therefore, confirmation of such etiology requires referral of the patient for targeted tests. Conclusions: Invasion of host cells by atypical pathogens such as C. trachomatis and infections with “genital mycoplasmas” can disrupt the function of these cells and lead to many complications, including infertility. The immune response with the production of proinflammatory cytokines such as TNF-α, IL-1β, and IL-6, observed in response to infection with C. trachomatis, M. hominis, and Ureaplasma spp., induces or amplifies inflammation by activating immune cells or controlling infection, but may lead to the facilitation of the survival of pathogenic microorganisms and irreversible damage to fallopian tube tissues. Especially in the case of the proinflammatory cytosine TNF-α, there seems to be a close correlation with infections with atypical pathogens and a marked immune response, as well as with increased IL-1β and IL-6 values compared with the absence of infection (both in the presence and absence of PCOS). The presented study may suggest the importance of extended diagnostics to include atypical pathogens in the case of PCOS and the importance of research in this area also from the point of view of the immune response. Full article

Photodynamic therapy (PDT) is a non-invasive therapeutic method with over a century of medical use, especially in dermatology, ophthalmology, dentistry, and, notably, cancer treatment. With an increasing number of clinical trials, there is growing demand for innovation in PDT. Despite being a promising treatment for cancer and bacterial infections, PDT faces limitations such as poor water solubility of many photosensitizers (PS), limited light penetration, off-target accumulation, and tumor hypoxia. This review focuses on chlorins—well-established macrocyclic PSs known for their strong activity and clinical relevance. We discuss how nanotechnology addresses PDT’s limitations and enhances therapeutic outcomes. Nanocarriers like lipid-based (liposomes, micelles), polymer-based (cellulose, chitosan, silk fibroin, polyethyleneimine, PLGA), and carbon-based ones (graphene oxide, quantum dots, MOFs), and nanospheres are promising platforms that improve chlorin performance and reduce side effects. This review also explores their use in Antimicrobial Photodynamic Therapy (aPDT) against multidrug-resistant bacteria and in oncology. Recent in vivo studies demonstrate encouraging results in preclinical models using nanocarrier-enhanced chlorins, though clinical application remains limited. Full article

The aim of this study was to examine the genetic characteristics that could be associated with the virulence characteristics of Escherichia coli collected from clinical samples. A collection of 100 non-repetitive E. coli isolates was analyzed. All isolates were typed by MLST. String production, biofilm formation and serum resistance were examined for all isolates. Twenty E. coli isolates were completely sequenced Illumina platform. The results showed that the majority of E. coli isolates (87%) produced significant levels of biofilm, while none of the isolates were positive for string test and resistance to serum. Additionally, the presence of CRISPR/Cas systems (type I-E or I-F) was found in 18% of the isolates. Analysis of WGS data found that all sequenced isolates harbored a variety of virulence genes that could be implicated in adherence, invasion, iron uptake. Also, WGS data confirmed the presence of a wide variety of resistance genes, including ESBL- and carbapenemase-encoding genes. In conclusion, an important percentage (87%) of the E. coli isolates had a significant ability to form biofilm. Biofilms, due to their heterogeneous nature and ability to make microorganisms tolerant to multiple antimicrobials, complicate treatment strategies. Thus, in combination with the presence of multidrug resistance, expression of virulence factors could challenge antimicrobial therapy of infections caused by such bacteria. Full article

The Asian tiger mosquito Aedes albopictus is a highly invasive species capable of transmitting human pathogens. For population management, the sterile insect technique (SIT) is considered an effective and sustainable alternative to conventional methods, such as insecticides and reducing or eliminating breeding sites. The use of symbiotic bacteria to improve the application of SIT or design combined SIT/incompatible insect technique (IIT) approaches is currently considered. In this context, exploring the microbiota of local mosquito populations is crucial for identifying interesting components. This study employed 16S rRNA sequencing and microbiological methods to characterize the diversity of laboratory and wild Ae. albopictus in Greece. Differences were recorded between wild and lab-reared mosquitoes, with laboratory samples exhibiting higher diversity. Laboratory treatment, sex, and developmental stage also resulted in variations between communities. Populations reared in the same facility developed mostly similar bacterial profiles. Two geographically distant wild populations displayed similar bacterial profiles, characterized by seasonal changes in the relative abundance of Pantoea and Zymobacter. Wolbachia was dominant in most groups (63.7% relative abundance), especially in field-caught mosquitoes. It was identified with two strains, wAlbA (21.5%) and wAlbB (42.2%). Other frequent taxa included Elizabethkingia, Asaia, and Serratia. Blood feeding favored an increase in Serratia abundance. Various Enterobacter, Klebsiella, Aeromonas, and Acinetobacter strains were isolated from larval and adult mosquito extracts and could be further characterized as diet supplements. These findings suggest that the microbiota of local populations is highly variable due to multiple factors. However, they retain core elements shared across populations that may exhibit valuable nutritional or functional roles and could be exploited to improve SIT processes. Full article

The FIC domain-containing protein Sofic has recently been shown to provide robust protection to bacteria against phage infection. Sofic acts as a toxic protein, inducing abortive infection through the AMPylation of target proteins during phage invasion. However, the molecular mechanisms regulating Sofic’s toxic activity remain elusive. In this study, we identified a small gene encoding a short protein located downstream of Sofic in the genome, named AS1 (anti-Sofic1), which functions as an antitoxic protein to counteract Sofic’s toxicity. The crystal structure of Sofic revealed that the protein functions as a dimer in solution, with dimerization being indispensable for its toxic activity. Importantly, structural analysis indicated that ATP binding induces a conformational change in the C-terminal domain (CTD) of Sofic, underscoring the critical role of the CTD in mediating its toxic effects. In vitro colony-forming assays confirmed that the interaction between the CTD and the Amylase domain is crucial for Sofic’s toxic activity. Overall, our results provide molecular insights into the regulatory mechanisms of Sofic in antiviral immunity. Full article

Defensins, one of the members of the antimicrobial peptide family, play a vital role in resisting microbial invasion and immune regulation. Porcine β-defensin 2 possesses excellent stability, making it an ideal antibiotic alternative for feed additives. In this study, a total of 15 piglets were used to investigate the effects of supplementing diets with 2.5 mg/kg (LP group) and 5 mg/kg (HP group) of pBD2 to weaned piglets. The results revealed that pBD2 significantly increased the total weight gain and average daily weight gain (p < 0.05), the contents of T-AOC, SOD, IgM, and IL-10 in serum (p < 0.05), the villus-to-crypt ratios, and the expression of tight-junction proteins ZO-1 and claudin-1 (p < 0.05) in the small intestine. Furthermore, pBD2 increased the abundance of beneficial bacteria related to nutrient and energy metabolism while decreasing the abundance of harmful bacteria associated with intestinal inflammation and diarrhea. Alterations in the gut microbiota were closely associated with the levels of T-AOC, SOD, IgM, and IL-10 in serum. pBD2 primarily enhanced the health of weaned piglets by influencing antioxidant capacity, intestinal barrier function, and the intestinal microbiota. Our research provides a novel perspective for addressing the issue of antibiotic residues in feed. Full article

Antinutritional Factors (ANFs) are compounds produced by plants as defense mechanisms, and in high concentrations, they inhibit nutritional properties. Reducing these ANFs increases the presence of proteins, antioxidants, and vitamins, which is crucial for optimizing animal feed, particularly in developing countries where traditional methods may be costly. Solid-state fermentation (SSF) has the potential to improve the nutritional quality of animal feed derived from cereals and legumes cultivated and non-commercially cultivated by reducing antinutrients and enhancing nutrient availability. This review also considers the potential of non-native species, including those exhibiting invasive behavior and taxonomic similarity to cultivated varieties, as alternative substrates for SSF. Additionally, SSF highlights the biological properties of ANFs when extracted and utilized for technological and industrial advancements. Solid-state fermentation with lactic acid bacteria could be an effective and straightforward method for reducing these antinutritional factors while simultaneously enriching protein content. The aim is to present solid-state fermentation as a biotechnological tool to reduce antinutritional factors and enhance the nutritional content of legumes and cereals that are not cultivated for animal feed. This perspective contributes to expanding the range of raw materials considered for SSF by including taxonomically related but underutilized and ecologically problematic plant resources. Full article