Pathogens最新文献

Enteritis is a common and recurrent disease in shrimp aquaculture, causing significant economic losses and management challenges. However, its specific causative pathogen remains unclear. Here, a pathogen strain, Vibrio parahaemolyticus VSP1, was directly isolated from shrimp with enteritis, and its pathogenicity and genomic characteristics were analyzed. Diseased shrimp exhibited lethargy, empty gut, hepatopancreatic atrophy, and severe intestinal damage. The gut bacterial community of diseased shrimp differed significantly from healthy shrimp (PERMANOVA, p < 0.05), with a 129% increase in Vibrio relative abundance. Nine Vibrio operational taxonomic units (OTUs) were enriched in diseased shrimp, and the dominant OTU1 shared 100% 16S rRNA identity with VSP1. VSP1 grew rapidly, utilized diverse carbon sources, and induced enteritis symptoms in over 90% of challenged shrimp. Genome analysis revealed 98.34% average nucleotide identity with V. parahaemolyticus ATCC 17802 and identified 156 putative virulence-related genes, mainly related to adherence, motility, and secretion systems. Unlike the strain ATCC 17802, VSP1 lacks thermostable direct hemolysin (TDH) and type III secretion system 2 (T3SS2), but contains alternative virulence factors such as Yersinia-like type IV pili and lipooligosaccharides, suggesting a distinct virulence strategy. This study identifies the pathogen responsible for shrimp enteritis and provides a foundation for targeted control strategies in aquaculture.

Introduction: This study was designed to determine the differences between brucellosis patients whose standard tube agglutination test (SAT) titers decreased or not after successful treatment. Methods: This retrospective study included patients with a course of antibiotic therapy at least 6 weeks for acute brucellosis or 12 weeks for osteoarticular involvement, and whose post-treatment clinical findings improved. Results: The mean age of the 276 patients was 45.2 years, and 50.7% were female. The SAT titer decreased in 166 patients (60%). No significant differences were found in terms of demographical and epidemiological characteristics between the groups. Patients with decreased SAT titers exhibited an elevated pre-treatment erythrocyte sedimentation rate (ESR) and the lymphocytosis was more prevalent. In the non-decreased SAT group, liver enzymes such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values after treatment were higher. The initial SAT titer of 1/160 and the pre-treatment rates of anaemia and thrombocytopenia were significantly higher in patients whose SAT titers became negative. Among patients whose SAT titers remained positive, the initial SAT titer was more frequently ≥1/320, and the post-treatment AST value was higher. Conclusions: This study showed that a serological response can be obtained with a high ESR and lymphocytosis prior to treatment. It should be noted that SAT negativity cannot be observed immediately in patients with pre-treatment SAT titers ≥ 1/320. The healthcare providers are advised to consider the complete clinical picture without relying solely on serological results.

The Journal retracts the article "Rapid Generation of Coronaviral Immunity Using Recombinant Peptide Modified Nanodiamonds" [...].

Feline calicivirus (FCV) is widespread in multi-cat environments and typically causes acute upper respiratory tract disease (URTD). FCV also causes outbreaks of virulent systemic disease (VSD), mainly in adults, with multiple organ involvement. In this study, an FCV-VSD infection was described in a less-one-month-old Maine Coon kitten originating from a cattery where an outbreak of FCV-URTD had previously been reported. After spontaneous death, post-mortem examination as well as histopathological, immunohistochemical, bacteriological and virological investigations were carried out. Pathological findings were consistent with severe pneumonia and cutaneous oedema of the footpads. No concomitant bacterial infection was detected. FCV RNA was detected in several organs and the highest amount of viral RNA was observed in the lung sample, in which the presence of the FCV antigen was confirmed by immunohistochemistry. With the same immunohistochemical technique, the IBA-1 antibody detected sparse alveolar macrophages, the main viral target cell and pulmonary replication site. The nucleotide sequences of the viral ORF2 gene amplified from all positive tissues were identical with each other and phylogeny confirms that highly virulent FCV strains are not distinguishable from FCV-URTD phenotypes. Our findings reinforce the hypothesis that VSD outbreaks can occur even in small populations, due to the high genetic variability of FCV.

Antimicrobial resistance in healthcare-associated infections represents one of the greatest threats to global health. The COVID-19 pandemic disrupted infection control and antimicrobial stewardship, potentially affecting the prevalence of pathogens and the development of resistance. This study aimed to investigate the prevalence, antimicrobial resistance, and clonal dissemination of ESKAPE pathogens isolated from bloodstream infections during the second year of the COVID-19 pandemic in four tertiary-care hospitals in Mexico. A total of 926 isolates were analyzed: Staphylococcus aureus (22.4%), Klebsiella pneumoniae (22%), Acinetobacter baumannii (21.5%), Pseudomonas aeruginosa (12.5%), Enterobacter cloacae (9.4%), Enterococcus faecalis (8.4%), and Enterococcus faecium (3.8%). High rates of multidrug resistance were observed in A. baumannii (70.9% XDR) and K. pneumoniae (71% XDR plus MDR with 79% ESBL). P. aeruginosa and E. cloacae showed the highest susceptibility rates (53% and 48%, respectively) to all antimicrobials. The main β-lactamases involved in resistance were bla_SHV, bla_CTX-M, and bla_TEM in K. pneumoniae, while the predominant carbapenemases were bla_OXA-24, bla_OXA-23 in A. baumannii, bla_NDM in K. pneumoniae, and bla_VIM in P. aeruginosa. Among Gram-positives, methicillin-resistant S. aureus accounted for 33.8% of isolates, and vancomycin resistance was higher in E. faecium (28%) than in E. faecalis (1.3%). Pulsed-field gel electrophoresis revealed endemic circulation of A. baumannii clones (Pulsotypes 1AC, 2AM), persistent for over a decade, and interhospital dissemination of S. aureus and K. pneumoniae clones. These findings underscore the epidemiological relevance of MDR ESKAPE pathogens during the COVID-19 pandemic and highlight the urgent need to optimize empirical therapy and maintain continuous genomic surveillance to enhance infection control in Mexican hospitals.

Rheumatic heart disease (RHD) remains a major cause of preventable morbidity in low- and middle-income countries. As the most serious sequel of acute rheumatic fever (ARF) caused by Streptococcus pyogenes, RHD arises from molecular mimicry that drives autoimmune damage of cardiac valves. We systematically reviewed human studies (1977-2025) following PRISMA to clarify systemic immune signatures associated with valvular pathology. Searches of PubMed, LILACS, ScienceDirect, and Web of Science found 29 studies: 22 RHD and 7 ARF. In ARF, elevations in IL-6, IL-8, IL-17F, GM-CSF, TNF-a, and CXCL10 occurred alongside increased activity of CD4⁺ Th1 and MAIT cells. In RHD, a consistent inflammatory-fibrotic profile emerged with raised IL-17, IFN-γ, TNF-a, TGF-β1, Tenascin-C, and prothymosin alpha (ProTα) in blood and valve tissue. CD4⁺ and CD8⁺ T cells were implicated in valve injury; ProTα correlated with cytotoxic activity of circulating CD8⁺ T cells. Several mediators (IL-6, TNF-a, IL-8, CXCL10, CCL2, CCL19) were identified in RHD studies as being associated with inflammation, cell recruitment, and clinical severity. Systemic dysregulation mirrored local valve inflammation, suggesting circulating molecules may index ongoing cardiac damage. These findings underscore a central role for T cells and pro-inflammatory cytokines in RHD and highlight candidate prognostic markers and therapeutic targets to inform translational studies and trials.

Borrelia garinii is a spirochete associated with Lyme borreliosis and is widely distributed across Eurasia. Although its genomic features have been well characterized in Europe, genomic data from East Asian isolates remain limited. Two B. garinii strains, HN13 and HN18, were isolated from a wild rodent (Apodemus agrarius) in South Korea and subjected to whole-genome sequencing and comparative genomic analysis. Their genomic features were compared with those of a tick-derived Korean strain 935 and additional global reference genomes. Phylogenetic analyses revealed that B. garinii strain HN18 clustered closely with French strains CIP103362 and 20047, whereas B. garinii strain HN13 showed high chromosomal similarity to the Korean strain 935. Both rodent-derived strains harbored plasmids carrying virulence-associated genes, including vlsE and vls silent cassettes, which were absent in B. garinii strain 935. This study provides new genomic insights into B. garinii circulating in East Asia and reveals host-associated plasmid variation linked to virulent potential. This study also suggests possible trans-Eurasian gene flow and underscores the need for continued genomic surveillance to better understand the evolution and epidemiology of Borrelia species.

Salmonella species isolated from chicken meat pose an increasing threat to public health. According to ECDC data, salmonellosis cases have shown a significant upward trend in many European countries between 2019 and 2023, almost reaching pre-pandemic levels. EFSA reported 77,486 confirmed human cases in the EU in 2023. This corresponds to a notification rate of 18 cases per 100,000 people, compared to 15.4 cases per 100,000 in 2022. This study evaluated the prevalence of Salmonella spp., antimicrobial resistance (AMR) profiles, and the effectiveness of natural biological preservatives in raw chicken meat obtained from retail outlets in Southeast Turkey. Among 100 samples analyzed according to ISO 6579-1:2017, suspicious colonies were detected after selective enrichment in XLD and n = 3 isolates were confirmed to be Salmonella enterica subsp. enterica serovar Infantis by real-time PCR. Disk diffusion tests performed in accordance with EUCAST showed that all isolates were resistant to beta-lactam, tetracycline, trimethoprim, sulfonomid and aminoglycoside groups. All isolates were classified as multidrug-resistant. PCR detected blaTEM-1 (all isolates), aphA1-IAB (all isolates), aadA1 (two isolates), and sul1 (all isolates), while tetA/tetB genes were not detected. Among the natural compounds tested, carvacrol showed the strongest antimicrobial activity (MIC 1.56 µL/mL; MBC 3.125-6.25 µL/mL; inhibition zones 32-35 mm). Eugenol showed moderate effects with higher MIC/MBC values (3.125-6.25 µL/mL/12.25 µL/mL), while α-terpineol was effective only at higher concentrations. These findings are consistent with the global increase in Salmonella Infantis and AMR, supporting carvacrol followed by eugenol and α-terpineol as promising natural alternatives for controlling MDR Salmonella spp. in food safety applications.

Bacterial liver abscess (BLA), accounting for approximately 80% of all liver abscesses, is a severe suppurative infection of the liver. Although gut microbiota dysbiosis has been implicated in BLA pathogenesis, causal evidence remains limited. Here, we integrate Mendelian randomization (MR) and clinical cohort studies to systematically evaluate the causal role of gut microbiota in BLA. Using summary-level genetic data from MiBioGen, GWAS Catalog, and the Pan-UK Biobank, we identified several causal microbial taxa: Coprococcus, Veillonellaceae (including Dialister), and Klebsiella were positively associated with BLA risk, whereas Bacteroides and Bifidobacterium appeared protective. Clinical validation confirmed significant enrichment of Veillonella, Dialister, and Streptococcus in the gut and oral microbiota of BLA patients, contrasting with the predominance of Bacteroides and Bifidobacterium in healthy controls. Klebsiella was the most abundant genus in abscess pus, and gut microbial metabolic profiling revealed marked upregulation of glycolytic pathways in BLA patients. These results indicate that gut dysbiosis exacerbates BLA development through microenvironmental disruption and metabolic reprogramming. Our findings provide mechanistic insights into BLA etiology and suggest microbiota-targeted interventions as promising strategies for prevention and treatment.