Abstract

Escherichia coli remains a leading aetiology of bacterial disease in poultry and food-borne illness in humans, worldwide. There are reports on the changing trends in antimicrobial resistance pattern of animal pathogens with very limited information available on E. coli isolates from free-range chickens in Ibadan. This study was therefore designed to investigate the characteristics and antibiogram of E. coli from indigenous chickens in Live Bird Markets (LBMs) in Ibadan, Nigeria. In a cross-sectional survey, 100 cloacal swabs were obtained from indigenous chicken from three LBMs in Ibadan, namely Oje (n = 34), Moniya (n = 34) and Bode (n = 32). E. coli was isolated using standard procedures. Initial identification of E. coli was by morphological, biochemical, and gram staining characteristics. PCR amplification of the 16S rRNA gene of E. coli was done using standard primers. Sequences were analysed, deposited in the Genbank and Phylogenetic trees were constructed using MEGA 11.0 software. Antibiotic susceptibility pattern of the isolates was investigated utilizing the disc diffusion technique and interpreted according to CLSI 2020 guidelines. Data were analysed using descriptive statistics at P < 0.05. E. coli colonised 43% of the samples with a higher frequency of isolation from male chickens (46%), and those from Oje market (52.9%). There was close phylogenetic relatedness with other strains from Egypt, Portugal and Iraq. Several strains were multi-drug resistant with leading resistance to Metronidazole (100%), Doxycycline (81.40%) and Streptomycin (76.74%) and in various combinations. Isolates were mostly sensitive to Enrofloxacin (100%) and Gentamicin (88.37%). Free-range indigenous chickens in Ibadan harbor multi-drug resistant E. coli strains which may be a source of food contamination. Improved hygiene while handling indigenous chickens is recommended.