Molecular Detection of Plasmid-Mediated Quinolone Resistance in Salmonella Typhi Isolated from Stool of Patients Attending Selected Primary Health Centres in Kaduna Metropoilis, Nigeria

Fluoroquinolones have been the drug of choice for the treatment of Salmonellla infections in humans and animals. The emergence of fluoroquinolone resistant Salmonella strains has posed significant treatment challenges worldwide. This research is aimed at detecting the Plasmid mediated quinolone resistant genes of Salmonella typhi isolated from stool samples of patients attending selected Primary Health Centres in Kaduna metropolis. Methodology: A total of 200 stool samples were randomly collected from patients with suspected Typhoid fever using standard protocols. Salmonella typhi was isolated from the samples using standard culture and microbiological techniques. Antibiotics susceptibility testing was done using the disc diffusion method to investigate the ability of Salmonella typhi to resist the tested antibiotics. The bacterial genome was extracted and resistant genes were detected using PCR. Results. Out of the 200 stool samples, 61(30.5%) Salmonella typhi was isolated. Out of the 61 isolates, 44 (72.1%) carried resistant genes of which 6 of the isolates carried the Ciprofloxacin resistance genes. The genes that were discovered mainly were QnrB, aac(6’)-Ib-cr-R and QepA. Conclusion: The antibiotic susceptibility testing of Salmonella typhi in this study showed an increasing trend of plasmid mediated quinolone resistance (PMQR). The allele B of qnr gene was found to be the predominant cause of PMQR in this study.