Bacterial pathogens in Jiangxi poultry (2023-2024): Prevalence and antimicrobial resistance profiles.

Poultry-associated bacterial infections cause substantial economic losses and exacerbate antimicrobial resistance, which poses significant threats to food safety and public health. We conducted epidemiological surveillance of bacterial pathogens isolated from poultry flocks in Jiangxi Province between 2020 and 2022. This study extends that monitoring for a two-year period (2023-2024), continuing the prevalence tracking and antimicrobial resistance surveillance of avian bacterial pathogens across the province. During this surveillance period, 547 tissue and fluid samples were collected from clinically diseased poultry (ducks, geese, and chickens), with a bacterial isolation rate of 50.5% (276/547). Among all 311 bacterial isolates, the most prevalent pathogens were Avian Pathogenic Escherichia coli (APEC) (53.1%), Riemerella anatipestifer (15.8%), and Salmonella spp. (14.1%). APEC exhibited the highest mean prevalence (35.1%) throughout the five-year investigation. Antimicrobial susceptibility testing was performed on all bacterial isolates using 20 antimicrobial agents from 11 drug classes. The APEC strains demonstrated high resistance rates (>80%) to the following agents: erythromycin, tilmicosin, tiamulin, amoxicillin, enrofloxacin, ampicillin, chlortetracycline, sulfadiazine, ceftiofur, and florfenicol. Multidrug resistance was prevalent among the tested isolates, with the highest rates observed in Salmonella (100.0%) and Enterococcus (100.0%), followed by APEC (99.4%), R. anatipestifer (98.0%). Our findings provide detailed insights into the current status of bacterial infections and antimicrobial resistance in Jiangxi Province's poultry industry, offering evidence-based guidelines for veterinarians to combat bacterial diseases.