Toxigenic Clostridium difficile in retail packed chicken meat and broiler flocks in northeastern Iran

This study was designed to evaluate the occurrence of Clostridium difficile in both broiler chicken farms and packed chicken parts sold at market places in Mashhad, the second most popular Islamic pilgrimage city after Mecca in northeastern Iran. The fresh faecal samples were obtained from broiler farms, while the chicken packs were purchased from retail outlets across the city at market places and samples were obtained from the necks, thighs, and wings. The selective culture was used for isolation of C. difficile. Out of 40 pooled fresh faecal and 65 packed chicken samples, 14 (35%) and 10 (15.3%) samples were positive, respectively. Some of the C. difficile isolates from chickens packs (7 out of 10, 70%) and faecal samples (5 out of 14, 36%) were detected as toxigenic (A, B and binary toxins) using molecular identification. From 14 isolates of the faecal samples, five isolates were tcdA and tcdB positive, and none was binary toxin positive. The results of the present study suggest that broiler chickens are a potential source of C. difficile, which may infect humans through contact or consumption of chicken meat, although the significance of food contamination is entirely unclear, the role of poultry products as a potential source of the infection should be investigated.