Isolation and identification of Campylobacter spp. and Campylobacter coli from poultry carcasses by conventional culture method and multiplex PCR in Mashhad, Iran

The genus Campylobacter is of great importance to public health because it includes several species that may cause diarrhoea. Poultry and poultry products are known as important sources of human campylobacteriosis. In this study, during the autumn months of 2005, a total of 100 samples from poultry carcasses, representing 20 broiler flocks were obtained by rinse test, after the chilling stage of processing. The samples were enriched in Preston broth, followed by streaking on selective media. Then, the suspected colonies were isolated on sheep blood agar and tested for morphology, motility and Gram-staining. Biochemical tests and hippurate hydrolysis activity were also performed. Concurrently, a multiplex PCR assay (m-PCR) with two sets of primers was employed for identification of Campylobacter genus and Campylobacter coli. The m-PCR assay was applied on bacterial cultures harvested from selective media plates. By conventional culture method, including hippurate hydrolysis test from suspected colonies, 76% of samples were positive for Campylobacter spp. and 2% for C. coli. In m-PCR assay 28% of the harvested cultures, were positive for Campylobacter genus but C. coli were not detected in any of the samples. According to this preliminary study, it seems that the contamination rate of poultry carcasses with other species of Campylobacter genus is higher than contamination with C. coli.