Antimicrobial Activity of Oxytetracycline on Escherichia Coli Isolated from Chicken in Sokoto, Nigeria

This study explored the prevalence and pattern of antimicrobial activity of Oxytetracycline on Escherichia coli (E. coli) isolated from chicken presented with cases of diarrhoea at the Avian Clinic of the Veterinary Teaching Hospital, Usmanu Danfodiyo University, Sokoto. Cloacal swab samples were taken from 50 chicken of various types and age groups with suspected Colibacillosis. Bacterial culture and identification was carried out, 72% of the isolates were presumed to be E. coli, with 40% confirmed after biochemical characterization. Distribution analysis indicated highest prevalence of the organism in layers (8 isolates), followed by broilers (7), local chicken (2), cockerels (2), and lastly noilers (1). No statistical significant differences were found among types of chicken using Chi square with P > 0.05%. Regarding age, 40% of the isolates were from young chicken, and 60% were from adult ones, with no statistical significant difference observed among them (P > 0.05%). Additional investigations, including polymerase chain reaction (PCR) analysis, were conducted to further confirm the isolates. Oxytetracycline susceptibility test to elucidate antibiotic resistance in these E. coli isolates revealed 30% sensitivity and a concerning 70% resistance, indicating a challenge in managing E. coli infections in chicken in Sokoto using oxytetracycline. E. coli isolated from commercial (exotic) chicken were found to be more resistant to oxytetracycline than the ones isolated from local chicken (77.8% and 0% respectively). E. coli isolates from adult chicken were found to be more resistant to oxytetracycline than the ones isolated from young chicken (75% and 62.5% respectively). In conclusion; this study identifies the substantial presence of oxytetracycline-resistant E. coli strains in chicken in Sokoto. Vigilant monitoring and judicious antibiotic use are crucial to curb further antibiotic resistance spread in poultry through creation of awareness among farmers and veterinary drug vendors about dangers associated with antibiotic resistance. Further in vivo studies should be undertaken to correlate the in vitro susceptibility results to help validate the findings and guide future treatment protocols