Whole-Genome Sequencing Uncovers Chromosomal and Plasmid-Borne Multidrug Resistance and Virulence Genes in Poultry-Associated

Background: Broad and unregulated antibiotic use in livestock production, particularly poultry farming, has increased the development and persistence of multidrug-resistant (MDR) bacterial strains in animals. These resistant pathogens and their antibiotic resistance genes (ARGs) can spread to humans through environmental exposure and the food chain, posing serious public health risks. Whole-genome sequencing (WGS), alongside phenotypic antimicrobial susceptibility testing (AST), enables a comprehensive understanding of resistance mechanisms and informs antimicrobial stewardship strategies, particularly in resource-limited settings. Aim: This study aimed to characterize the phenotypic and genotypic antimicrobial resistance profiles, plasmid content, and virulence factors of an MDR Methods: Results: Phenotypic testing revealed extensive resistance, with complete resistance to six of seven tested antibiotics (cefotaxime, ampicillin, erythromycin, gentamicin, ciprofloxacin, and doxycycline). MICs exceeded clinical breakpoints for multiple classes, confirming an MDR phenotype. Genome analysis indicated a 5.33 Mb genome distributed across five contigs, including one chromosome and four plasmid-associated contigs. The strain harboured numerous ARGs, including Conclusion: This study highlights the significant role of poultry-associated bacteria as reservoirs of AMR genes, particularly those harboured on mobile plasmids with potential for HGT.