To investigate the prevalence and pathogenic characteristics of avian reovirus (ARV) in the Xinjiang region of China, this study collected suspected joint tissue samples from broiler farms across different areas of the Taikun Group. The samples were subjected to virus isolation, RT-PCR analysis, sequence analysis, in vitro replication assays, and pathogenicity assessments in specific pathogen-free (SPF) chicken embryos and chickens. The results revealed the isolation of a chicken-derived ARV epidemic strain, designated as ARV xj-1.1. The virus-induced cytopathic effects (CPEs) in LMH cells and the time required to observe CPEs significantly decreased with serial blind passages. Pathogenicity testing demonstrated that ARV xj-1.1 is highly virulent to SPF chicken embryos and chickens. Inoculation of SPF chicken embryos resulted in a 100% mortality rate, while inoculation of 1-day-old SPF chicks caused significant swelling of the footpads. In conclusion, this study successfully isolated an epidemic strain of avian reovirus, providing a valuable theoretical basis for understanding the genetic evolution and epidemiology of ARV variants in the Xinjiang region.

Avian reovirus (ARV) causes a range of diseases in poultry and results in significant economic losses for the poultry industry. To address the epidemic of ARV infection in yellow-feathered broilers in Xinjiang, this study conducted genetic and evolutionary analyses of a chicken-origin ARV field strain, designated ARV xj-1.1. The σC gene of this strain was expressed in vitro using both Escherichia coli and Pichia pastoris systems to compare expression characteristics and immunogenicity. Phylogenetic analysis revealed that ARV xj-1.1 belongs to genotype IV. The σC gene was successfully cloned and efficiently expressed in both prokaryotic and eukaryotic systems. After purification by nickel affinity chromatography, recombinant proteins pET-σC and GS115/pPIC9K-σC were obtained. Post-translational modification analysis indicated that neither recombinant protein exhibited glycosylation; however, phosphorylation levels differed, with values of 5.9% and 21.7%, respectively. Immunogenicity evaluation showed that both recombinant proteins induced high antibody titers in mice (1:51,200 for pET-σC and 1:102,400 for GS115/pPIC9K-σC). In immunized chicks, antibody levels peaked in the third week post-vaccination, and neutralizing antibody titers were significantly higher than in the control group (P < 0.01). Challenge experiments confirmed that vaccinated chicks exhibited no clinical symptoms or gross lesions, whereas the challenged controls displayed classic signs such as depression, swollen footpads, and visceral hemorrhage. These results demonstrate that the σC protein possesses strong potential as a subunit vaccine antigen. Although the eukaryotically expressed protein exhibited higher phosphorylation, the prokaryotically expressed σC protein induced a stronger neutralizing antibody response. This study provides a theoretical and experimental foundation for the development of regional ARV subunit vaccines and has important implications for controlling ARV infections among poultry in Xinjiang.

The objective of this study was to evaluate the physiological mechanisms and health resilience of Duroc pigs reared in an outdoor system compared to a conventional indoor system. A total of 24 Duroc pigs (approximately 3 months of age) were randomly assigned to either an indoor (IN, n = 12) or an outdoor (OUT, n = 12) rearing system for a 45-day trial. Growth performance (body weight and ADG) and spleen organ index were not significantly different between the two rearing systems (p > 0.05). Hematological profiles, including leukocyte and erythrocyte indices, showed no significant differences (p > 0.05), although plateletcrit tended to decrease in the OUT group (p = 0.08). For serum biochemical parameters, pigs in the OUT group exhibited significantly higher concentrations of total protein, triglycerides, calcium, and sodium compared to those in the IN group (p < 0.05). Additionally, serum albumin and glucose levels tended to be higher in the OUT group (p < 0.01). No significant differences were observed in liver and muscle enzyme activities (AST, ALP, GGT, CK) between the treatments (p > 0.05). In conclusion, outdoor rearing did not compromise growth performance or induce chronic physiological stress or tissue damage in Duroc pigs. Instead, it promoted active energy and lipid mobilization, enhanced protein metabolism, and improved mineral homeostasis, demonstrating the robust physiological adaptability of the Duroc breed to outdoor environments.

Neonatal meningitis-associated Escherichia coli (NMEC) is a formidable pathogen in veterinary medicine. The emergence of atypical, multidrug-resistant (MDR) variants complicates disease control. An Escherichia coli (E. coli) strain was isolated from the brain tissue of a deceased calf with acute meningitis. Comprehensive characterizations were performed, including whole-genome sequencing (WGS), multi-locus sequence typing (MLST), antimicrobial susceptibility testing (AST), murine pathogenicity assays, and RT-qPCR evaluation of neuroinflammatory cytokines. Results: The isolate (O18ab:H14) was identified as a capsule-deficient NMEC strain belonging to phylogroup A and sequence type ST1434. WGS showed that the genome size of this strain is 5.1 Mb, containing 73 strictly defined antimicrobial resistance genes and 202 virulence factors. These may be involved in the compensatory mechanism for capsule deficiency, and further functional verification is required. Phenotypically, it exhibited a robust MDR profile. In the murine model, the strain demonstrated high lethality, and induced severe multi-organ lesions characteristic of both meningitis and systemic sepsis. While intraperitoneal injection bypasses natural colonization routes, the brain-specific bacterial persistence and neuronal pathology imply neurotropic potential. Furthermore, RT-qPCR confirmed a severe neuroinflammatory response, marked by the significant upregulation of IL-1β, IL-6, and TNF-α in the infected brains. This study characterizes a novel, highly virulent, and MDR capsule-deficient NMEC/SEPEC hybrid strain. The findings emphasize the urgent need for continuous genomic surveillance of atypical E. coli pathotypes in livestock.

This study aimed to investigate the antimicrobial resistance, virulence gene profile, and pathogenicity of Enterococcus faecium isolated from a large-scale cattle farm in Xinjiang, China, to provide a scientific basis for the prevention and control of E. faecium infections in the region. Nineteen rectal swabs were aseptically collected from diarrheic calves for bacterial isolation. Isolates were identified through morphological observation, biochemical characterization, and PCR amplification. Homology analysis was conducted using 16S rRNA gene sequencing. Antimicrobial susceptibility was evaluated by the disk diffusion method, and key virulence genes were detected using PCR. Pathogenicity was assessed through intraperitoneal inoculation of mice, followed by histopathological examination. Three isolates were identified as E. faecium, consistent with morphological and molecular results. Biochemical tests indicated that the strains could metabolize sucrose, maltose, lactose, melibiose, and raffinose, but not sorbitol. Phylogenetic analysis revealed that isolates SCQ3 and SCQ4 shared 99.3% homology with E. faecium strain MF678878.1, while SCQ11 showed 91% similarity to strain JP2. Antimicrobial susceptibility testing indicated that SCQ11 was resistant to vancomycin. PCR analysis identified the presence of multiple virulence genes, including psaA, hyp, asal, sprE, nuc, cbh, srtA, hyl, scm, and agg. In vivo pathogenicity testing demonstrated that the vancomycin-resistant strain exhibited strong virulence in mice, with gross lesions observed in the liver, spleen, and intestines. Histopathological examination confirmed varying degrees of tissue damage, particularly in the liver and spleen. All three E. faecium isolates exhibited multidrug resistance, with one strain showing vancomycin resistance and harboring a high number of virulent genes. This strain demonstrated significant pathogenicity in vivo. These findings highlight the potential public health threat posed by multidrug-resistant E. faecium in livestock and provide essential data for regional prevention and control strategies.

This study aimed to classify Escherichia coli phages using bioinformatics analysis systematically and to establish corresponding PCR and qPCR detection methods for rapid molecular typing and identification. Based on 419 complete E. coli phage genomes available in NCBI, phylogenetic and pan-genomic analyses were conducted to classify the phages at the family, subfamily, and genus levels and to identify highly conserved core genes. Specific primers targeting these core genes were designed, and their specificity, sensitivity, and reproducibility were verified using conventional PCR and dye-based qPCR. A total of 357 phages were successfully classified, encompassing 10 families, 20 subfamilies, and 67 genera. Pan-genomic analysis identified type-specific core genes within 16 taxa, including Ackermannviridae and Demerecviridae, for which 16 pairs of primers were designed. Validation using bacteriophages isolated from Xinjiang cattle farms showed distinct single PCR bands with high specificity, and the qPCR assay achieved a sensitivity of up to 10⁻⁵ µg/µL. This study established an efficient and broad-spectrum molecular typing and detection method for E. coli phages, providing a powerful preliminary screening tool for phage selection.