Salmonella Saintpaul is a foodborne pathogen of public health relevance. This study characterised 79 S. Saintpaul isolates from human clinical and food sources collected in Singapore from 2015 to 2017. Isolates belonged to ST3602 (91.1%, n = 72), ST27 (6.33%, n = 5), ST49 (1.27%, n = 1) or ST50 (1.27%, n = 1). ST3602 predominated in both human (92.5%) and food (89.7%) isolates. Human and food isolates showed the highest resistance to penicillins and beta-lactam/beta-lactamase inhibitor combinations. The analysis identified beta-lactam resistance genes (blaCTX-M-1, blaTEM-1D), aminoglycoside resistance genes (aph(4)-Ia, aac(3)-IVa, aadA), and fluoroquinolone resistance genes (qnrS) as the most prevalent. Notably, 31.6% of isolates identified as extended-spectrum beta-lactamase (ESBL)-producing and all ESBL-positive isolates exhibited multidrug resistance. Plasmids were predicted in 75.9% (n = 60) of the isolates, with IncI1-I(Alpha) being the most common incompatibility group and showing a strong association with blaCTX-M-1 (Fisher’s exact test, p < 0.001; Φ = 0.913). Single-nucleotide polymorphism (SNP) analysis revealed close genetic relatedness between chicken and human isolates at relatively low SNP distances (0–16 SNPs), suggesting potential shared transmission pathways. This study provides epidemiological insights and antimicrobial resistance landscape of S. Saintpaul in Singapore, informing strategies for food safety and public health surveillance.
Hepatitis A virus (HAV) infection remains a global public health concern in both developing and developed countries. In the present study, we identified anti-HAV drugs, using AutoDock Vina Modeling software, and evaluated the compounds in vitro. Following cytotoxicity for Huh7 cells, 5 out of 10 compounds were selected. We evaluated effective HAV 3C protease inhibitors with activity against both HAV genotype IB HM175/18f and HAV genotype IIIA HA11-1299-infected human hepatoma cells. Among the five compounds, we identified only one (KCN-A-12), which had an inhibitory effect on both HAV genotype IB HM175/18f and HAV genotype IIIA HA11-1299 replication in human hepatoma Huh7 cells. KCN-A-12 has more effective inhibitory effects on the replication of HAV genotype IB HM175/18f than that of HAV genotype IIIA HA11-1299. This difference may be attributable to the fact that our discovery system depends on crystal structures from HAV 3C protease based on the HAV genotype IB HM175 strain. In conclusion, we observed that KCN-A-12 was able to inhibit HAV replication. In silico screening for HAV 3C protease inhibitors may be useful for further discovery of anti-HAV drugs.
Gonococcal and chlamydial conjunctivitis and keratoconjunctivitis are potentially sight-threatening ocular manifestations of sexually transmitted infections. Recent epidemiological data indicate rising rates of gonorrhoea and chlamydia infections worldwide, raising concerns about a possible increase in associated ocular infections. This retrospective single-center study analyzed the frequency and temporal trends of laboratory-confirmed gonococcal and chlamydial ocular infections in adults treated at the University Hospital Zurich between January 2005 and July 2025. Clinical characteristics, treatment, complications, and outcomes were additionally assessed for gonococcal cases. We identified 17 gonococcal and 121 chlamydial conjunctivitis or keratoconjunctivitis cases over the past approximately 20.5 years. A marked increase in gonococcal cases was observed between 2021 and 2025 (p < 0.0001), during which 70.6% of all cases were diagnosed. Complications occurred in 41.1% of gonococcal infections, including one corneal perforation requiring keratoplasty. Although gonococcal conjunctivitis and keratoconjunctivitis remain rare, their recent increase and risk of severe ocular complications highlight the importance of early recognition and prompt treatment. In contrast, chlamydial conjunctivitis was more common, affected a younger population, and showed a significant declining trend, with an average annual decrease of 5% (p = 0.0015).
Background: Aircraft wastewater (AWW) provides a composite environmental matrix reflecting passengers from diverse geographic origins and may serve as a surveillance tool for AMR monitoring. Objectives: To characterize microbial community composition, antimicrobial resistance genes (ARGs), virulence factor genes (VFGs), and genome-resolved features of AWW. Methods: Samples (N = 10) were collected from long-haul flights arriving in the UAE between October 2024 and February 2025. Shotgun metagenomic sequencing and high-throughput quantitative PCR (HT-qPCR) were performed. Metagenome-assembled genomes (MAGs) were reconstructed. Results: Shotgun metagenomics identified 752 bacterial species dominated by gut-associated families, including Lachnospiraceae and Ruminococcaceae. A total of 345 ARGs were detected, with tetracycline resistance genes being most abundant. Regional variation in resistome composition was supported by permutational multivariate analysis of variance (PERMANOVA, p = 0.010), and principal coordinate analysis indicated separation by flight-origin region. MAG reconstruction recovered 1012 genomes, with 85.4% resolved to species level. MAG-based annotation identified 280 VFGs corresponding to 116 non-redundant virulence genes. HT-qPCR confirmed the widespread presence of key ARG classes and mobile genetic elements across samples, in keeping with metagenomic findings. Conclusions: AWW contains diverse microbial communities and AMR determinants. Genome-resolved analysis provided organism-level context for resistome and virulome characterization, confirming AWW as an environmental matrix for monitoring transboundary AMR dynamics.
Osteoporosis is one of the most prevalent metabolic bone diseases worldwide, and current pharmacological options are limited by adverse effects and are poorly suited to long-term use, underscoring the need for novel therapeutic targets. Bifidobacterium, one of the most representative beneficial bacterial genera in the human gut, has been linked to bone mineral density, and supplementation with specific strains improves bone metabolic parameters in animal models of osteoporosis. This narrative review examines the molecular mechanisms through which Bifidobacterium may protect bone via the gut–bone axis, encompassing four interconnected dimensions: reinforcement of the intestinal barrier, modulation of the immune network, remodeling of the gut microbiota, and production of bone-protective metabolites. The review makes three principal contributions. First, it establishes a four-tier mechanistic framework of Bifidobacterium-mediated regulation of osteoporosis in which the evidence is stratified into three categories—direct evidence from Bifidobacterium-specific studies, indirect evidence from other probiotics, and general mechanisms of gut microbiota-regulated bone metabolism—thereby strengthening the rigor of each argument and explicitly distinguishing evidence derived from Bifidobacterium-specific studies from that based on other probiotics or general gut-microbiota mechanisms throughout the review. Second, it systematically compares the osteoprotective efficacy of different Bifidobacterium strains (Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium adolescentis, etc.), highlighting the central importance of strain specificity. Third, it evaluates the strength of the evidence and identifies knowledge gaps for each mechanistic pathway. Most current evidence derives from cross-sectional studies and animal models; causal relationships await validation in large-scale prospective cohort studies and randomized controlled trials. In addition, functional disparities among strains and heterogeneity across clinical studies remain the core bottleneck in translating these fundamental findings into clinical practice.
This study investigated the adaptive mechanisms of Shigella sonnei ATCC25931 in response to gamma irradiation stress (0.5 and 1 kGy), with a specific focus on the involvement of fatty acids (FAs) in membrane lipid composition remodeling, adherence, and extracellular proteins. The results demonstrated a notable enhancement in cell hydrophobicity and adherence to KB cells following irradiation, although the invasion rate exhibited a decline from 14% to 2.35% at 1 kGy. Furthermore, gamma irradiation induced notable alterations in fatty acid (FA) composition, characterized by a pronounced reduction in the unsaturated/saturated FA ratio. Additionally, the plasmid profiles revealed the loss of several original plasmids after gamma irradiation. The alterations in extracellular proteins were observed through SDS-PAGE, which demonstrated a reduction in expression at 1 kGy. Furthermore, a molecular docking analysis indicated that fatty acids play a role in inhibiting VirF, a key regulator of Shigella virulence. The least effective inhibitor was capric acid, while linoleic and gamma-linolenic acids formed the most stable inhibitory complexes, which prevented VirF from activating the virulence system. These alterations in fatty acids, plasmids, and extracellular proteins constitute adaptive responses to irradiation-induced stress.
In the post-pandemic era, identifying children who are most susceptible to severe illness and COVID-19-related mortality is essential for guiding public health policies. This study examined the risk factors for COVID-19-related severe illness and mortality from 2023 to mid-2025. We conducted a population-based cohort study using nationwide Brazilian data from patients aged <18 years with laboratory-confirmed SARS-CoV-2 infection between January 2023 and June 2025. The primary outcomes were COVID-19-related severity and death. Separate binary multivariable logistic regression models were developed for each of the outcomes. Among 465,689 children, 1.3% (n = 5963) developed severe illness, and 0.18% (n = 847) died. Factors associated with an increased risk of severe illness included age < 2 years, presence of comorbidities, Indigenous ethnicity, and lack of vaccination. Neurological disorders conferred the highest risk among the clinical conditions (adjusted odds ratio [aOR] = 34.1; 95% CI: 27.9–41.8). Regional differences were also observed; the North and Northeast regions showed higher mortality (aOR = 2.3; 95% CI: 1.8–3.0) than the Central-West region. Compared with White ethnicity, non-White ethnicities had higher mortality: Indigenous (aOR = 23.5; 95% CI: 13.5–39.3), Black (aOR = 1.95; 95% CI: 1.29–2.92), and Brown (aOR = 1.43; 95% CI: 1.18–1.73) ethnicities. Lack of any vaccine dose was associated with a significantly increased risk of severe illness (aOR = 1.39; 95% CI: 1.15–1.67. p < 0.001) and death (aOR = 2.1; 95% CI: 1.3–3.5; p < 0.001). In the post-pandemic era, younger age, comorbidities, sociodemographic disparities, and lack of vaccination were associated with an increased risk of severe illness and COVID-19-related death in the pediatric population.
Extremophilic exopolysaccharides (EPSs) from extreme-environment microorganisms exhibit multifunctional and specific properties relevant to food, pharmaceutical, and environmental applications. This study reports the physicochemical characteristics of a novel EPS secreted by the marine actinobacterium Janibacter limosus (JlEPS) isolated from the Tyrrhenian Sea. The biopolymer was characterized for its molecular mass, monosaccharide composition, functional groups, rheological, and thermal behavior. JlEPS was found as an acidic heteropolysaccharide composed of eight sugar monomers. Neutral and acidic sugars predominate, with glucose (36.60 ± 0.46 mol%), rhamnose (23.62 ± 0.15 mol%), and galacturonic acid (16.54 ± 0.18 mol%). Amino sugars were also detected, including galactosamine (8.70 ± 0.01 mol%) and glucosamine (4.00 ± 0.10 mol%). Arabinose (7.8 ± 0.76 mol%), galactose (1.35 ± 0.01 mol%), and fucose (1.42 ± 0.06 mol%) were present in minor amounts. The average molecular weight (Mw) of the biopolymer was 1.60 × 106 Da, with a polydispersity index of 1.022, indicating a relatively homogeneous population. FT-IR indicated uronic acids and glycosidic linkages, while TGA demonstrated stability up to 250 °C. JlEPS solutions behaved as pseudoplastic fluids, and the flow curves were fitted with the Carreau model (R2 = 0.96–0.99). The zero-shear viscosity increased from 0.542 ± 0.187 Pa·s (0.5%) to (5.01 ± 0.91) × 104 Pa·s, while the flow index decreased from 0.368 ± 0.032 to 0.100 ± 0.028, confirming strong pseudoplasticity and extensive molecular entanglements. JlEPS is a complex with a defined composition and high viscosity, supporting its potential for multiple applications.
Rumen development and microecological homeostasis are critical for post-weaning health in lambs; however, effective nutritional strategies combining probiotics and antimicrobial peptides remain underexplored. This study investigated the effects of graded doses of a combined additive (Candida utilis + antimicrobial peptide (AMP)) on rumen development and microecology in weaned Hu lambs. Forty healthy pre-weaning male lambs (initial body weight: 15.77 ± 1.25 kg; age: 42.98 ± 1.80 d) were randomly assigned to four groups (n = 10): a control group (CK, fed milk/basal diet), and three treatment groups receiving the same milk/basal diet supplemented with graded doses of the combined additive, based on feed intake (LCB: AMP 0.05 g/kg + C. utilis 0.1 g/kg, MCB: AMP 0.05 g/kg + C. utilis 0.8 g/kg, HCB: AMP 0.05 g/kg + C. utilis 1.5 g/kg) over a 40-day period starting from day 6. At the end of the trial, six lambs per group were randomly selected for sampling for analyses of rumen morphology, fermentation parameters, 16S rRNA amplicon sequencing, and untargeted metabolomics. Results showed that, compared with CK, (1) MCB and HCB increased papilla height, and HCB also increased papilla width (p < 0.05); papilla width and muscular layer thickness showed significant linear increases with increasing additive dose (p < 0.05). (2) All treatments linearly reduced ruminal pH (p < 0.05), although all values remained within the normal physiological range; meanwhile, all treatment groups showed elevated levels of microbial protein (MCP), butyrate, valerate, and isovalerate; MCP also increased linearly with dose (p < 0.05); LCB decreased the acetate-to-propionate ratio(A:P), and this ratio exhibited a significant quadratic trend across treatment groups (p < 0.05). (3) HCB increased the α-diversity indices and reduced Methanobacteriota abundance; LCB elevated Bacillota; and all treatments decreased Spirochaetota, Synergistota, and Cyanobacteriota but increased Actinomycetota, Verrucomicrobiota, and Thermodesulfobacteriota (p < 0.05). (4) The number of differential metabolites and KEGG pathway enrichments gradually increased with increasing doses of the combined additive, with HCB exerting the most extensive modulatory effects on signaling and neural pathways. (5) Volatile fatty acids, Bacteroidota, and Xylanibacter were positively correlated with rumen development parameters (p < 0.05). Collectively, dietary supplementation with the combined additive improved rumen fermentation, microbial community structure, and metabolic profiles, with the high-dose (HCB) regimen showing the most effects on select parameters, whereas the low-dose (LCB) regimen exhibited advantages in specific fermentation traits. These findings provide preliminary evidence for the potential application of this combined additive in post-weaning lamb diets.
This retrospective, descriptive study examined the microbial distribution and antibiotic resistance profiles of predominant pathogens in chronic wounds among patients presenting to a regional hospital’s chronic wound outpatient clinic between July and November 2025, with the aim of informing empirical antibiotic therapy and regional antibiotic stewardship programs. Among the 105 patients included (mean age 62.69 ± 17.14 years, 60% male), diabetic foot ulcer was the most common wound type (49.5%). Of the isolates obtained, 70.2% (n = 73) were Gram-negative and 29.8% (n = 31) were Gram-positive microorganisms, with Escherichia coli and Pseudomonas aeruginosa being the most frequently isolated pathogens (16.3% each), followed by Staphylococcus aureus (15.4%). S. aureus predominated in diabetic foot ulcers, whereas P. aeruginosa predominated in peripheral artery disease, though no statistically significant association was found between wound type and bacterial group (p = 0.055). A multidrug-resistant phenotype was detected in 16.3% (17/104) of isolates. No significant differences emerged between Gram-negative and Gram-positive groups regarding HbA1c, WBC, and CRP levels (p > 0.05), although WBC and CRP showed a moderate positive correlation (ρ = 0.396, p < 0.001). These findings highlight the predominance of Gram-negative microorganisms and considerable antibiotic resistance in chronic wound infections, emphasizing that culture-based diagnosis remains essential since laboratory parameters cannot reliably predict the causative microbial group, and that empirical therapy should be guided by local resistance patterns.
Oilfield microbiome studies have extensively characterized microbial community composition or isolated individual hydrocarbon degraders, but integrated exploration of cultivable functional bacteria from paired crude-oil and produced-water environments remains limited, particularly for strains combining hydrocarbon utilization with stress-tolerance and biosurfactant-related traits. In this study, paired crude-oil and produced-water samples from the Huoshaoshan Oilfield were investigated by combining 16S rRNA amplicon sequencing with culture-dependent isolation and functional screening. A total of 135 bacterial isolates representing 22 genera were recovered, of which 70 showed hydrocarbon-utilizing potential in primary screening. The collection also included isolates capable of growth at 10% NaCl and up to 55 °C. Comparison of sequencing and cultivation revealed marked differences between environmental abundance and recoverable functional resources. Representative isolates showed distinct removal profiles toward n-tetracosane (C24), naphthalene, phenanthrene, and fluoranthene under saline conditions, with Halomonas nitritophilus Ff1 and Halomonas sp. Fc15 showing particularly strong performance. Sequence-confirmed alkB and PAH-RHDα fragments provided additional molecular support for the observed hydrocarbon-removal phenotypes. A three-strain consortium composed of Sphingomonas sp. Fa24, Halomonas nitritophilus Ff1, and Stutzerimonas stutzeri Ff2 achieved 87.4% C24 removal, exceeding the corresponding monocultures. These findings link oilfield microbial community profiling with cultivable functional resource mining and provide candidate strains for saline petroleum bioremediation.
Cyclospora cayetanensis is a foodborne parasite that causes the human diarrheal disease cyclosporiasis. Multiple outbreaks of C. cayetanensis have been linked to Mexican-style dishes containing uncooked cilantro. The Bacteriological Analytical Manual (BAM) Chapter 19b method for the detection of C. cayetanensis has been validated in cilantro, but not in complex foods containing cilantro, such as fresh salsa/pico de gallo. In a previous study, specific modifications of the BAM method were performed in fresh salsa/pico de gallo for optimal detection of C. cayetanensis. In the present study, further evaluation of those modifications in fresh salsa/pico de gallo were performed using the updated BAM Chapter 19b mitochondrial-based qPCR (Mit1C qPCR). Six FDA laboratories analyzed six blind-coded salsa/pico de gallo test samples each. These samples included two unseeded samples, three samples seeded with five oocysts, and one sample seeded with 200 oocysts. All laboratories performed the updated washing and DNA extraction modification steps. The overall C. cayetanensis detection rates across laboratories for fresh salsa/pico de gallo samples inoculated with 200 oocysts, five oocysts, and un-inoculated samples were 100% (6/6), 100% (18/18), and 0% (0/12), respectively. The method showed extremely high sensitivity and high reproducibility across all laboratories. Un-inoculated samples were all negative for each laboratory, indicative of high C. cayetanensis specificity. This is the first evaluation of the performance of detection of C. cayetanensis using the updated BAM Chapter 19b (Mit1C qPCR) in a complex matrix, e.g., fresh salsa/pico de gallo. A second study evaluated the presence of the parasite in a long-term study in fresh salsa/pico de gallo samples inoculated with C. cayetanensis and analyzed up to three weeks after inoculation. Samples were positive for the detection of the parasite at each time-point of the study, indicating that the method could be used to detect the parasite in leftovers of fresh salsa/pico de gallo up to three weeks old in outbreak investigations. Evaluation and deploying effective methods to detect C. cayetanensis in high-risk fresh produce and prepared dishes are critical to monitor and respond to active outbreaks.
Tuberculosis (TB) remains one of the most significant global public health challenges, as it represents the world’s leading infectious cause of death. The clinical efficacy of currently available anti-TB drugs is increasingly compromised due to the growing prevalence of antibiotic-resistant strains, side effects, and prolonged treatment times. This scenario highlights the urgent need to identify new anti-TB drugs with alternative mechanisms of action and improved anti-TB activity and bioavailability. In this context, natural products derived from microorganisms represent a key source of chemical diversity for drug discovery. Actinomycetes, fungi, and other environmental microbes produce a wide range of secondary metabolites with broad antimicrobial activity. These compounds can interfere with essential bacterial structures and processes, including membrane integrity, redox homeostasis, protein synthesis, and DNA replication. This review aims to evaluate new microbial natural products for their antibacterial activity, focusing on their efficacy, mechanisms of action, chemical nature, and potential clinical applications, with the aim of informing the development of new anti-TB agents.
The specific differences, unique characteristics, and functional linkages of rumen microbiota and their metabolic pathways across different ruminant species remain poorly understood. To investigate these cross-species relationships, 16 Holstein cows, 28 Simmental crossbred cattle, and 15 Boer goats were fed under standardized conditions for 97 days. Rumen microbial composition and function were evaluated using 16S rRNA gene sequencing and PICRUSt. Results revealed distinct, host-specific microbial architectures. Holstein cows exhibited an overall enrichment of the phylum Proteobacteria and ABC transporter pathways. Notably, their micro-ecosystem was dominated by the Succinivibrionaceae_UCG-001 flora type, which is computationally associated with propionate synthesis for milk production and is predicted to potentially contribute to altered methane metabolism. In contrast, Simmental cattle were characterized by Succinivibrionaceae_UCG-002 and computationally upregulated glycolysis/gluconeogenesis pathways, which are associated with volatile fatty acid conversion for energy deposition. Furthermore, Boer goats harbored a unique fiber-adapted ecosystem exclusively enriched with the norank_f_Bacteroidales_BS11_gut_group and Lachnospiraceae_ND3007_group, correlating with butyrate production and maintaining a classic acetate-type fermentation profile, while exhibiting an elevated predicted genomic potential for methane production based on functional profiling. This study demonstrates that rumen microbiota, metabolic pathways, and fermentation parameters form a highly coordinated network shaped by host phylogeny, energy allocation, and specific diets, providing a theoretical basis for targeted microbiome modifications to improve animal health and feed utilization.
Tea quality is largely determined by the accumulation of specialized metabolites in fresh leaves, yet the effects of the propagation method on tea quality and its belowground ecological basis remain insufficiently understood. In this study, sexually propagated (SR) and asexually propagated (AR) tea plants were compared by integrating soil physicochemical analysis, leaf quality and physiological measurements, widely targeted metabolomics, and rhizosphere metagenomic profiling. Compared with AR, SR plants exhibited more favorable rhizosphere nutrient conditions, with soil organic matter, total nitrogen, alkali-hydrolyzable nitrogen, and available phosphorus increasing by 23.1%, 18.2%, 27.8%, and 161.5%, respectively, although available potassium decreased by 24.4%. SR leaves also contained higher dry matter, tea polyphenol, and soluble sugar contents, which increased by 11.5%, 58.8%, and 8.6%, respectively. In addition, superoxide dismutase, peroxidase, and indole-3-acetic acid oxidase activities were 30.4%, 92.0%, and 21.7% higher under SR, whereas hydrogen peroxide content remained unchanged. Metabolomic profiling revealed marked differences in leaf metabolic composition between the two propagation types, with differentially accumulated metabolites mainly enriched in flavonoid biosynthesis, phenolic acid metabolism, caffeine metabolism, carotenoid biosynthesis, plant hormone signaling, and α-linolenic acid metabolism. Rhizosphere metagenomic analysis further showed that SR was characterized by higher relative abundances of Actinomycetota, Pseudomonadota, Planctomycetota, Alphaproteobacteria, and Streptomycetales, together with distinct microbial functional profiles related to glycolysis, the tricarboxylic acid cycle, and pyruvate metabolism. Significant correlations were identified between several SR-enriched microbial taxa and quality-related metabolites, particularly flavonoids and phenolic acids. Overall, under the present field conditions, sexual propagation was more favorable than asexual propagation for tea quality formation, as reflected by improved nitrogen and phosphorus availability, greater accumulation of quality-related metabolites, higher antioxidant enzyme activities, and distinct rhizosphere microbial carbon-metabolic potential. These findings provide an integrated soil–microbiome–metabolome perspective for understanding propagation-related differences in tea quality.
The yak is an iconic ruminant of the Qinghai-Tibet Plateau, yet segment-specific variation in its intestinal microbial functional potential and bile acid profiles under different feeding systems remains insufficiently characterized. Six healthy adult male yaks with similar body weights (320 ± 30 kg) were assigned to grazing (G) or stall-feeding (S) systems, with three animals per group, for a 90-day trial comprising a 10-day adaptation period and an 80-day formal experimental period. The individual yak was considered the experimental unit, and intestinal segments sampled from the same animal were treated as repeated observations. Liver tissue and digesta from the duodenum, ileum, cecum, and colon were analyzed using targeted bile acid metabolomics and shotgun metagenomics. Principal coordinate analysis based on Bray-Curtis dissimilarities showed segment-associated clustering of microbial communities, with PCo1 and PCo2 explaining 65.5% and 18.9% of the total variation, respectively. ANOSIM identified a significant intestinal-segment effect on microbial community composition (R = 0.2208, BH-FDR = 0.0144), whereas the overall feeding-system effect was not significant (R = 0.3747, BH-FDR = 0.1200). No statistically significant feeding-system differences were detected in Shannon, Simpson, Chao1, or ACE indices within individual intestinal segments (BH-FDR ≥ 0.800), and PERMDISP detected no significant differences in within-group dispersion (BH-FDR ≥ 0.1682). Bacillota and Bacteroidota were the dominant phyla. Descriptive functional profiling showed higher mean ileal abundances of GH2 (0.0035 vs. 0.0026), GH3 (0.0029 vs. 0.0024), and GH43 (0.0021 vs. 0.0013) in grazing yaks, whereas the starch-associated GH13 family showed its highest mean abundance in the colon of stall-fed yaks. These metagenomic patterns represent predicted genomic functional potential rather than gene expression, enzyme activity, or metabolic flux. Cecal total bile acid concentration showed a nominal between-group difference (unadjusted Welch’s p = 0.0109), but this difference did not remain significant after correction across the five anatomical sites (BH-FDR = 0.0545). In the colon, stall-fed yaks had a lower conjugated-to-unconjugated bile acid ratio and a higher secondary-to-primary bile acid ratio than grazing yaks (BH-FDR < 0.05). Feeding-system-associated descriptive patterns were observed in predicted microbial functional profiles, whereas statistically supported between-group differences were limited mainly to selected colonic bile acid ratios. Given the limited animal-level replication, these findings should be considered exploratory.
Feline calicivirus (FCV) is a highly heterogeneous pathogen and a major cause of feline upper respiratory tract disease, highlighting the need for continuous surveillance of its genetic diversity and pathogenic characteristics. In this study, we isolated and comprehensively characterized a newly isolated FCV strain, HN/ZZ/2025, from cats at a feline trading market in Zhengzhou, China, and systematically evaluated its molecular features, in vitro replication characteristics, physicochemical properties, and pathogenicity in cats. Phylogenetic analysis classified HN/ZZ/2025 as genotype GI. The isolate replicated efficiently in CRFK, F81, and Fc3Tg cells, reaching peak titers of 107.18, 107.50, and 105.89 TCID50/0.1 mL, respectively, and exhibited typical calicivirus-like particles with diameters of 35–40 nm. Complete genome analysis showed that HN/ZZ/2025 shared the highest nucleotide and amino acid sequence identities of 85.7% and 62.8%, respectively, with the closely related Chinese FCV strain CH-JL4, and revealed distinct amino acid variations within the hypervariable E region of the VP1 capsid protein. Experimental infection of cats (n = 3/group) resulted in pyrexia, with rectal temperatures reaching 39.8–40.2 °C, weight loss, oral ulceration, and persistent viral RNA shedding from 1 to 21 days post-infection. Viral RNA and VP1 antigen were detected in the lungs, trachea, kidneys, and spleen, indicating systemic dissemination and broad tissue distribution. Although no mortality occurred during the observation period, the observed clinical signs, viral dissemination, and histopathological lesions indicate that HN/ZZ/2025 is capable of causing clinically evident disease in experimentally infected cats. These findings provide useful insights into the molecular epidemiology, tissue tropism, and host–virus interactions of circulating FCV strains and establish HN/ZZ/2025 as a useful isolate for future studies of FCV genetic diversity and pathogenesis.
Enterotoxigenic Escherichia coli (ETEC) is a leading cause of bacterial diarrheal illness in low- and middle-income countries and among travelers to endemic regions, impacting morbidity and mortality and impairing childhood development. Despite its significant importance in public health, the propensity of ETEC diarrhea in endemic settings is influenced by complex interactions among epidemiological, immunological, environmental, and pathogen-related factors. This review aims to provide a comprehensive understanding of ETEC diarrhea in endemic regions by examining epidemiological trends, host immune responses, environmental determinants, and progress in current ETEC vaccine development. We discuss disease burden, seasonality, age-specific susceptibility, toxin and colonization factor diversity, and their relation to diarrheal disease severity at the community level and in hospitalized patients. In addition, we summarize current knowledge on natural immunity, including mucosal and systemic immune responses induced in ETEC-infected diarrheal patients. The review further highlights advances in ETEC vaccine development, focusing on candidate vaccines, safety, immunogenicity, protective efficacy, and challenges associated with implementation in resource-limited settings. By integrating clinical, microbiological, immunological, environmental, and public health perspectives, this review provides a multisectoral framework to better understand ETEC pathogenesis and prevention. It also highlights future research priorities, vaccine strategies, and policy interventions to reduce the burden of ETEC-associated diarrhea in endemic settings.
Paper mulberry (Broussonetia papyrifera) is a high-protein forage, but its high buffering capacity and low water-soluble carbohydrate (WSC) content hinder silage fermentation. This study evaluated the effect of tea tree (Melaleuca alternifolia) essential oil (TTO) as a natural additive for paper mulberry silage. TTO was added at 0 (CK), 500 (CSD), and 1000 mg/kg (CSG) fresh weight, with samples collected on days 7, 15, 30, and 90. After 90 days, CSD had the lowest pH and the highest lactic acid content. NH3-N/TN was significantly lower than in CK (p < 0.05), and the retention of dry matter, crude protein and water-soluble carbohydrate was improved (p < 0.05). Compared with CK, CSD exhibited the highest lactic acid bacteria (LAB) counts, along with the lowest mold and aerobic bacterial counts (p < 0.05). However, CSG did not further improve fermentation quality, and most of the indicators were not significantly different from CSD (p > 0.05). The in vitro gas production test showed that CSD significantly increased the theoretical maximum gas production and the maximum gas production rate (p < 0.05). Additionally, 16S rRNA sequencing revealed a distinct bacterial succession in CSD, which enriched beneficial lactic acid bacteria (LAB) such as Pediococcus while outcompeting less competitive taxa. This microbial reshaping redirected the community toward acidification and nutrient retention. Collectively, these results demonstrate that TTO at 500 mg/kg is a promising natural additive for improving paper mulberry silage quality through selective reshaping of the bacterial community.
Identifying the causative pathogen of paediatric osteoarticular infections (OAIs) is essential for guiding management. Kingella kingae infections are generally milder than pyogenic infections, which may have more severe and lasting consequences. Because standard inflammatory markers have limited discriminatory value, we assessed whether complete blood count-derived immune–inflammatory biomarkers (IIBs) could provide a simple, low-cost diagnostic aid. We retrospectively reviewed children younger than 5 years admitted to a tertiary hospital with confirmed OAIs. K. kingae cases were included from 2007 to 2025 and pyogenic cases from 1997 to 2025. Admission clinical data, conventional inflammatory markers, and six IIBs—NLR, MLR, PLR, SII, SIRI, and PIV—were analysed. The cohort included 118 K. kingae and 39 pyogenic OAIs. Pyogenic infections were associated with higher admission temperature and CRP levels and lower lymphocyte counts. All six IIBs were significantly increased in pyogenic infections and showed excellent univariable discrimination, with AUCs of 0.92–0.94. In a common complete-case cohort, the clinical model incorporating age, admission temperature, and CRP achieved an optimism-corrected AUC of 0.848. Adding lymphocyte count or an individual IIB increased corrected AUCs to 0.951–0.962; apparent AUCs were significantly higher than that of the clinical model after Holm adjustment. The abnormal-IIB-count model achieved the highest corrected AUC of 0.970; apparent sensitivity and specificity at the Youden-optimal threshold were 97.3% and 90.3%, respectively, but it did not significantly outperform the model with lymphocyte count alone. Routine CBC-derived IIBs may improve early differentiation between K. kingae and pyogenic OAIs, although external validation is required before clinical implementation.
