Detection of Salmonella enterica serovar Infantis in broiler flocks of Ardabil province and determination of its antibiotic resistance patterns

Salmonellosis is one of the most important zoonotic diseases in the world which caused by different Salmonella serotypes. In recent years, the prevalence of Salmonella serogroup C, especially S. Infentis has increased in poultry flocks. Therefore, The aim of this study was to detect S. Infentis in broiler flocks in Ardabil province and to determine their antibiotic resistance patterns to thirty the common antibiotics in Iranian Medical and Veterinary Centers. Five carcasses were randomly selected from 23 slaughtered broiler flocks and sampled from liver, skin, cecum and heart using sterile swabs. After culture and isolation of Salmonella, colonies were identified by biochemical and serological methods. Antibiotic susceptibility and resistance of the isolates were determined according to the standard method of disc diffusion. Out of 445 samples. 13 Salmonella isolates (2.92%) were recovered which belonged to three broiler flocks. From 13 Salmonella isolates, 11 isolates (84.62%) belonged to serogroup C and two isolates (15.38%) belonged to serogroup D. In serotyping tests of 11 serogroup C isolates, 10 isolates (90.9%) were identified as S. Infentis. Antibiograms test performed on S. Infentis isolates showed that the isolates were resistant to tetracycline, chlortetracycline, flomequine and nalidixic acid and were susceptible to ceftriaxone and cephaloselin. Multi-resistance was observed among S. Infentis isolates. Resistance at least to 4 drugs and up to 15 drugs. The results of this study showed that the presnce infection of S. Infentis in broiler flocks of Ardebil province, and also existence of drug resistance to common antibiotics in veterinary medicine field. These findings are important for public health concerns.