Molecular characterization of quinolone resistance genes (qnr) in Salmonella ‎typhimurium isolated from food samples

Salmonellosis is an important disease in animals and human which is caused by different serovars of Salmonella ýenterica. Serovars Typhimurium is one of the most prevalent sorvars in humans. Quinolones and floroquinolones ýare the family of extended-spectrum antibiotics which are used in salmonellosis treatment. Qnr genes are the ýplasmid-mediated quinolones resistance which leads to resistance in Enterobacteiacea. The aim of this study is ýidentification of quinolone resistance genes qnr in Salmonella Typhimurium isolated from food samples. In this ýstudy, 60 Salmonella samples isolated from food was collected and confirmed by culture and biochemical tests. ýSerotyping was done by O and H antisera. Multiplex-PCRþ þý was performed to identify qnrA, qnrB and qnrS genes. ýAll of the 60 isolates were confirmed as Salmonella by culture and biochemical tests. The results of serotyping ýshowed all the 60 isolates were belonged to serogroup B and serovar Typhimurium. Multiplex-PCR test showed 5 ýsamples had the qnrB, 4 had the qnrS and 1 harboured qnrA gene. The results of this study shows the presence of ýqnr genes in Salmonella Typhimurium isolated from food samples which has a specific public health importance. ýTherefore, there should be sureveillance and montoring programs to prevent this quinolone resistance.ý