Detection and antibiotic sensitivity pattern of avian pathogenic Escherichia coli strains among rural chickens in the arid region of north-eastern Nigeria

Abstract

Aim: To know the prevalence of avian pathogenic Escherichia coli (APEC) strains among adult apparently healthy rural chickens slaughtered in Maiduguri, north-eastern Nigeria. Materials and Methods: Cloacal swabs were examined by Gram staining, biochemical tests such as indole, methyl red, Voges-Proskauer and citrate (IMVC) tests and serotype by standard slide agglutination test with antisera against somatic antigen using six monospecific “O” antisera to E. coli belonging to the avian pathogenic E. coli group namely O1, O2, O26, O78, O86 and O141. The sensitivity of the isolated APEC strains to 10 antibiotics of human and veterinary use was also determined. Results: Out of a total of 510 samples examined, 356 (69.8%) were positive for E. coli. Of this number 20 (5.6%) samples were positive for O1, 20 (5.6%) for O2, 0 (0%) for O26, 25 (7.0%) for O78, 25 (7.0%) for O86 and 24 (6.7%) for O141 serotypes. The remaining 242 (68.0%) E. coli isolates were non typable with the 6 sera of avian pathogenic E. coli strains used for the study. The sensitivity profile of the isolates showed complete resistance of all the isolates against ampicillin, tetracycline, nalidixic acid and cefuroxime, while on the other hand all the isolates showed very high susceptibility to oxofloxacin followed by ciprofloxacin and gentamycin. The result of this study suggests that multiple-antimicrobial-resistant APEC isolates are present in rural chickens in Maiduguri, north-eastern Nigeria. In addition to animal health problems created by the resistant strains, there may also be potential danger posed to human health because these strains could easily infect humans through the food chain. Conclusion: The result of this study suggests that multiple-antimicrobial-resistant APEC isolates are present in rural chickens in Maiduguri, north-eastern Nigeria. Consequently, introduction of surveillance programs to monitor antimicrobial resistance of pathogenic bacteria is strongly recommended in Nigeria.