Molecular Epidemiology of Fluoroquinolones Resistance Genes among Non-typhoidal Salmonella Species from Humans and Poultry Faeces in Ido-Ekiti, Ekiti State

Abstract

Non-typhoidal Salmonella (NTS) strains are among the most common bacterial pathogens associated with antimicrobial resistance (AMR) where animals are known to be the major reservoir of NTS despite improvements in hygiene and sanitation. This study aimed to investigate the prevalence and basis of fluoroquinolone resistance genes in non-typhoidal Salmonella (NTS) recovered from human and poultry fecal samples in Ido Ekiti. The study used a total of 300 fecal samples,100 from humans and 200 from poultry sources. Faecal samples were cultured using Selenite F broth and XLD agar. Isolates were identified using morphology, biochemical tests, and molecular characterization. Antibiotic susceptibility were determined using disc diffusion test. Plasmid extraction and curing were done using alkaline lysis and Ethidium Bromide. Phylogenetic relatedness was determined using the Unweighted Pair Group Method with Arithmetic Mean. The results revealed that 10.7% of NTS were identified, with 9% from human and 11.5% from poultry sources. High resistance to ofloxacin (77.8%) was observed in both human and poultry samples. S. enteritidis from human sources had a concomitant presence of two qnr genes (qnrA and qnrS) at 20%, while only qnrS (60%) was detected from poultry sources. Statistically significant risk factors for NTS infection among human included the consumption of poultry products and the use of untreated poultry droppings. The study identified Qnr resistance gene in ESBL producing S. enteritidis from both human and poultry sources in Ido Ekiti and are plasmid borne, establishing the role of plasmids in the acquisition, and spread of antibiotic resistance of fluoroquinolones.