Characterisation of Antimicrobial Resistance Patterns in Poultry-Associated Bacteria in Southwest Nigeria: Implications for Public Health

This study characterises antimicrobial resistance patterns in bacteria isolated from commercial poultry farms and retail chicken meat in South West Nigeria, assessing the public health implications of resistance gene dissemination. Antimicrobial resistance in food-animal production systems is a global health emergency, and Nigeria's rapidly growing commercial poultry sector, with its widespread antibiotic use, represents a significant potential source of resistant bacteria affecting human health. This study collects 480 samples from broiler farms, abattoirs, and retail markets in Lagos, Ogun, and Oyo States. Samples include cloacal swabs, litter, abattoir surfaces, and retail chicken meat. Standard culture-based methods isolate Salmonella, Campylobacter, Escherichia coli, and Staphylococcus aureus. Antibiotic sensitivity testing uses Kirby-Bauer disc diffusion against 12 antibiotic classes following CLSI guidelines. Extended spectrum beta-lactamase-producing and methicillin-resistant Staphylococcus aureus isolates are characterised by polymerase chain reaction for resistance genes. Findings reveal that multidrug resistance, defined as resistance to three or more antibiotic classes, is detected in 68 percent of E. coli isolates and 52 percent of Salmonella isolates. ESBL-producing E. coli is present in 34 percent of retail chicken meat samples, indicating contamination with clinically significant resistance determinants. Fluoroquinolone resistance exceeds 58 percent in Campylobacter isolates, particularly concerning given the critical importance of this class for human campylobacteriosis treatment. The study contributes original Nigerian poultry AMR data and recommends immediate implementation of prescription-only antibiotic access policies and surveillance coordination between veterinary and human health sectors.

Keywords: antimicrobial resistance, poultry, public health, ESBL, South West Nigeria.