Determination of Antibiotic Resistance Patterns of Salmonella Serotypes Isolated from Broilers in Kermanshah Province

Objectives: The present study aimed to investigate the prevalence of Salmonella serotypes in slaughtered broilers in Kermanshah province and investigate the susceptibility of isolated Salmonella to antibiotics.Methods: In this cross-sectional, ۱۰ carcasses were randomly selected from each of ۲۵ slaughtered broiler flocks that were obtained from their cloacae. This study was conducted in ۲۰۱۴ in Kermanshah province. Samples were transferred into the Selenite F enrichment broth and incubated at ۴۳ °C for ۱۲-۱۸ h. Antibiotic susceptibility pattern of all isolates to be performed using the disk diffusion method. Also, the agglutination test on slide was performed on Salmonella isolates using the specific antisera to detect Salmonella serotypes.Findings: In the present study, ۲۵۰ (۳۳%) samples of Salmonella were isolated from ۷۵۰ cloacal samples of broilers. After serotyping, the most frequent serotype was as follow: Enteritidis serotype (۵۵.۲%), Infantis serotype (۳۸%) and Typhimurium serotype (۲۵.۶%). The results of antibiotic susceptibility pattern indicated that ۱۰۰% of strains were susceptible to gentamicin, enrofloxacin, imipenem and ceftriaxone; and the highest resistance was observed to nalidixic acid and nitrofurantoin. Furthermore, ۲۰۲ (۸۰%) out of ۲۵۰ Salmonella isolates had multiple resistance to three or more antibiotics and accounted as MDR isolates.Conclusion: According to the results of the present study, it is essential to detect pollution sources and pathogenic serotypes, the possibility of transferring Salmonella through poultry to humans and increasing the frequency of resistant isolates to antibiotics. It is strongly recommended to avoid the overuse of antibiotics without performing antibiotic susceptibility patterns.