Molecular Survey of Quinolone Resistance in Salmonella spp. Isolated From Poultry Products in Karaj, Iran

Non-typhoidal salmonellae and serovars of Escherichia coli, Listeria, Shigella, and Campylobacter are among the most important food-borne bacterial agents. The aim of the present study was molecular detection of quinolone resistance in Salmonella spp. isolated from poultry products in Karaj, Iran, using polymerase chain reaction (PCR). Ninety samples of poultry products were collected from different brands and markets during September-December 2017. All samples were enriched in nutrient broth and Selenite F broth, and salmonellae were isolated by xylose lysine deoxycholate agar. The presence of specific genes of qnrA, qnrB, and qnrS was investigated employing PCR technique and subsequently, specific primers. None of the 30 egg yolk samples had bacterial growth in the culture medium. In total, 29 (48.33%) out of 60 raw chicken meat samples were determined to be contaminated with Salmonella using culture-based methods (i.e., 7 (35%) out of 20 drumstick, 15 (62.5%) out of 24 breast, and 7 (43.75%) out of 16 liver samples). In addition, the frequency of qnrA, qnrB, and qnrS genes in the samples was 10.34%, 68.96%, and 86.20%, respectively. The results of this study showed a high frequency of Salmonella contamination and qnr genes in the contaminated samples.