Plasmid-Mediated Quinolone Resistance Genes Associated With Ciprofloxacin Resistance in Salmonella Typhimurium from Cattle Faeces from Abattoir in Keffi, Nasarawa State, Nigeria

The development of antimicrobial resistance by members of the genus Salmonella has a significant impact on the antibiotic treatment of Salmonella infections. This study investigated the plasmid-mediated quinolone resistance (PMQR) genes associated with Ciprofloxacin resistance in Salmonella typhimurium (S. typhimurium) from cattle faeces from abattoir in Keffi, Nasarawa State, Nigeria. A total of Four hundred (400) samples of cattle faeces were collected from abattoir and S. typhimurium were isolated and identified using standard microbiological methods. Antimicrobial susceptibility of the isolates was tested and interpreted in accordance with the Clinical and Laboratory Standards Institute (CLSI) protocol. Plasmid-Mediated Quinolone Resistance (PMQR) genes in ciprofloxacin resistant isolates were screened for using polymerase chain reaction (PCR) method. Of the 400 samples, the occurrence of S. typhimurium was 46 (11.5%). The isolates were more susceptible to gentamicin (87.1%), chloramphenicol (78.3%), streptomycin (69.6%) and ciprofloxacin (67.4%). The occurrence of multi-drug resistance (MDR) isolates was 46 (100%). The order of occurrence of PMQR genes in the ciprofloxacin resistant isolates was: aac (6′)-Ib-cr (66.7%) > oqxAB and qnrB (26.7%) > qnrS (20.0%). Gentamicin, chloramphenicol, streptomycin and ciprofloxacin, were the most effective antibiotics against the isolates. All the isolates were MDR and the most common PMQR gene detected in the ciprofloxacin resistant isolates was aac (6′)-Ib-cr. Further studies on the molecular diversity of PMQR S.typhimurium isolates from the study location should be carried out.