Distribution of TEM-1 Gene in Salmonella enterica Isolated from Poultry Carcasses in Iran

Abstract

Salmonella is one of the most important bacteria isolated from poultry and a major source of bacterial infection to human. The aim of present research was to study TEM-1 beta-lactamase gene in serovars of S. enterica subsp. enterica isolated from poultry carcasses samples in Iran. A total of 600 samples of poultry carcasses were collected and Salmonella was isolated from the samples using bacterial culture methods and genomic DNA was extracted using DNA extraction kit. For the final approval of Salmonella, identification of S. enterica subsp. enterica, S. enterica serovars and TEM-1 gene sequence-specific targets (16S rRNA, fliC, rfbJ, fljB and TEM-1 genes) were amplified using the PCR assay. Finally, antimicrobial resistance determination was carried out by standard Bauer-Kirby disk diffusion method. Out of the 600 poultry carcasses samples collected from big cities of Iran, 287 samples were positive for Salmonella spp. The results showed that 41.5% of the Salmonella spp. were positive for S. enterica subsp. enterica and the highest frequency of serovars was related to ser. Typhimurium (41.2%). Furthermore, 73.1% of the serovars were positive for TEM-1 gene. The results of present study showed a high prevalence of TEM-1 gene in the isolated Salmonella from poultry carcasses, also the highest frequency of serovars and TEM-1 gene significantly relating to S. Typhimurium (51.7%) and S. Enteritidis (31.0%). The highest rate of drug resistance and sensitivity were ampicillin (100%) and cefazolin (35%), respectively.