Simplex PCR Assay for Detection of blaTEM and gyrA Genes, Antimicrobial Susceptibility Pattern and Plasmid Profile of Salmonella spp. Isolated from Stool and Raw Meat Samples in Niger State, Nigeria

The global evolution of antibiotic resistance has threatened the efficacy of available treatment options with ravaging impacts observed in developing countries.As a result, investigations into the prevalence of antibiotic resistance and the role of plasmids are crucial.In this study, we investigated the presence and distribution of bla TEM and gyrA genes, plasmid profiles, and the antimicrobial susceptibility pattern of Salmonella strains isolated from raw meat and stool sources across Niger State, Nigeria.Ninety-eight samples, comprising 72 raw meat and 26 stool samples, were screened for Salmonella spp.The antimicrobial susceptibility of Salmonella isolates to 10 commonly used antimicrobial agents was determined using the Kirby-Bauer disc diffusion method.Isolates were further analyzed for plasmids, in addition to PCR amplification of beta-lactamase (bla TEM) and gyrA genes.A total of 31 Salmonella spp.were isolated, with 22 from raw meat (70.97%) and 9 from stool (29.03%).Salmonella spp. with multiple resistance patterns to ceftazidime, cefuroxime, ceftriaxone, erythromycin, ampicillin, cloxacillin, and gentamicin were detected.Ofloxacin and ciprofloxacin were found to be the most effective among the antibiotics tested, with 67.7% and 93.5% susceptible isolates, respectively.Nine (29.03%) isolates harbored plasmids with molecular sizes ranging between 6557 bp and 23137 bp.PCR amplification of gyrA was detected in 1 (3.23%) of the 31 isolates while 28 isolates (90.32%) were positive for bla TEM .This study shows the incidence of antibiotic resistance in Salmonella isolates and the possible role of plasmids; it also highlights the prevalence of ampicillin resistance in this local population.