PCR شناسايي كامپيلوباكترهاي بيماريزاي روده اي در مدفوع مرغ ها با روش

Detecting enteropathogenic Campylobacters in chicken feces by PCR and comparing with culture method

At present Campylobacters are the main cause of the bacterial diarrhea worldwide. In human beings the disease is transmitted by consumption of contaminated water and foodstuff, especially poultry products. Diagnosis of this bacterium is difficult by the bacteriological tests due to the long incubation period and unavailability of suitable differential tests. Hence, other diagnostic procedures, other than culture, are very demanding. Rectal swabs of 116 chickens from the poultry farms of lsfahan were enriched for 12 to 18 hours in Campy-Thio medium, and cultured in the Campylobacter selective agar medium. Gram staining, oxidase, catalase and hypurate hydrolysis tests and evaluation of sensitivity to nalidixic acid and cephalothin were employed for diagnosis and typing of the samples. For molecular evaluation of the samples, after DNA extraction, PCR was performed using two sets of type specific primers for C.coli and C.jejuni. Using culture, 11 samples (9.5%) were found positive from which 8 were jejuni and 3 were coli. Using PCR, 27 samples (23.2%) were positive, from which 18 were jejuni and 9 were coli. Sensitivity and specificity of PCR procedure in comparison to the culture were 100 and 84.7 percent. respectively. According to the results, all the culture positive samples were diagnosed and genotyped correctly using the PCR procedure. Therefore in view of its considerable sensitivity and speed, PCR could be a very reliable substitute for the culture method in Campylobacter detection in poultry samples.