Genotyping of isolates of Clostridium perfringens from vaccinated and unvaccinated sheep

Enterotoxaemia vaccine is a polyvalence vaccine from different types of Clostridium perfringens, and C. septicum toxins that prevents various diseases, the most important one being enterotoxaemia in sheep. The aim of the present study was to evaluate the enterotoxaemia vaccine effects in reducing isolates of intestinal clostridia genus specifically C. perfringens. Sheep dung samples were randomly collected from 10 places in Kerman, Iran. The samples were taken from 90 vaccinated Kermani sheep against enterotoxaemia and 50 unvaccinated sheep of same age from flocks with similar management. Following processing and culture of the samples, colonies were identified applying morphological, gram stain and biochemical tests. Using these tests C. perfringens were isolated from 27 out of 50 unvaccinated sheep (54.0%) and from 2 out of 90 vaccinated sheep (2.2%). All of the clostridia isolates were analyzed by multiplex PCR. Genotyping of 2 strains isolated from the vaccinated sheep indicated that these strains were type D, while the strains isolated from the unvaccinated sheep were types A, B, C and D; 14.8% (4 out of 27), 22.2% (6 out of 27), 40.7% (11 out of 27) and 22.2% (6 out of 27), respectively. However, no isolate containing the iota gene (type E) was detected. Vaccination against enterotoxaemia had a significant effect (P < 0.01) on reducing C. perfringens isolates. Occurrence of the disease in the vaccinated and unvaccinated groups was 3.3% and 64.0% (P < 0.01), respectively.