THE GENETIC TYPING OF SALMONELLA ENTERITIDIS ISOLATED FROM ROSS 308 BROILER CHICKENS IN GUILAN PROVINCE, IRAN

Salmonella enteritidis is one of the most important foodborne pathogens known to infect human and a wide range of animals, including poultry as a food source. Surveillance for S. enteritidis infection in broiler chickens (Ross 308 lineage) was performed in Guilan province, Iran. Aim of this study was to improve understanding of prevalence, antimicrobial resistance and genetic diversity of S. enteritidis isolated from broiler chicken farms in Guilan province. Between May 2016 and November 2018, 700 specimens were obtained from different broiler chicken farms. Isolated bacteria were tested and confirmed by serotyping, antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE). The overall detection rate of S. enteritidis was 7.5% (n = 53), antibiotic susceptibility test performed and the highest antibiotic resistance was observed in penicillin, macrolide, fluoroquinolone and tetracyclin group of antibiotics, respectively. All the 53 S. enteritidis isolates were analyzed by PFGE using enzyme XbaI, which generated 16 different pulsotypes (PT1-PT16) with similarity indices ranged from 82% to 100%. The present study showed the genetic relatedness of S. enteritidis isolates in broiler chickens with respect to their antimicrobial resistance (AMR). The data provided in this study may help authorities to have a good vision on the molecular typing and increased drug resistance of S. enteritidis in broiler chicken flocks.