Virulence and antibiotic resistance gene profiles of Iranian Salmonella spp. isolates in various origins

The aim of this study was to determine virulence and antibiotic resistance gene profiles of Iranian Salmonella spp. isolated from poultry, human, and dairy products. For this purpose, sixty-eight isolates including twenty clinical cases, forty-two poultry, and six dairy product isolates were collected. Virulence gene profiles including spiC, misL, and pipD were detected by PCR, and antimicrobial susceptibility test was carried out by using 8 antibiotic disks. PCR was also used to confirm the resistances for tetracycline, sulfamethoxazole, ampicillin, enrofloxacin, and gentamicin. There was a high frequency of virulence genes detected (spiC and pipD 92.6%, misL 89.7%). According to antimicrobial susceptibility tests, among all the isolates, the highest resistance was observed to tetracycline at 25.3% resistance. Another notable antibiotic resistance was for cephalothin (26.5%) and ampicillin (20.6%). The most sensitive were isolates from human origin. In some of tetracycline sulfamethoxazole, ampicillin, enrofloxacin, and gentamicin, resistance was confirmed by PCR. The results showed a significant incidence of antibiotic resistance of Salmonella isolates from poultry and food product isolates, which were further confirmed by genetic and molecular methods.