Objective: This is to investigate the implication of fluoroquinolone usage in veterinary practice and the food chain system.
Subjects and Methods: Five hundred isolates of commensal E coli were recovered from the faeces of apparently healthy cattle in Ado-Ekiti, Nigeria. The susceptibility of the bacteria was tested using standard laboratory procedures. Polymerase chain reaction (PCR) was carried out to detect the presence of qnrA and qnrB genes, which were selected on the basis of their fluoroquinolone-resistant patterns.
Results: The agar disc diffusion technique revealed that the representative isolates showed multiple fluoroquinolone-resistance and this formed the basis for their selection for PCR amplification. The PCR revealed that ten of the 17 quinolone-resistant representative isolates showed distinct bands which are specific for the qnrB gene; in addition, only one strain of the 20 representative isolates of commensal E coli carried plasmids on which the qnrA gene was detected.
Conclusion: This study has confirmed that plasmid-mediated quinolone resistance is a possible mechanism among the fluoroquinolone-resistant commensal E coli isolated from faeces of apparently healthy cattle in the study location.