Dr. P.T. RAMESHNITEESH KUMAR2021-01-212021-01-212016-07https://krishikosh.egranth.ac.in/handle/1/5810160488The present study was undertaken to determine the diagnosis of Clostridium perfringens type A in necrotic enteritis outbreaks in broilers. Necrotic enteritis in broilers was diagnosed based on clinical signs, necropsy lesions, culture examination and polymerase chain reaction. A total of 8 flocks with necrotic enteritis were selected and per flock 6 samples from diseased birds and 6 samples from healthy birds were taken. The intestinal contents or faecal sample was subjected for isolation and identification of the bacteria using cooked meat medium and perfringens agar. Fifty Clostridium perfringens isolates were obtained from 96 samples from diseased and healthy broiler birds. Out of 48 isolates, 37 (75 %) isolates were from diseased broiler chicken and from 48 isolates, 13 (25%) isolates were from healthy broiler chicken. These isolates of Clostridium perfringens were subjected to PCR and all the isolates produced the amplification for alpha toxin gene and typed as Clostridium perfringens type A. The morbidity and mortality rates varied between flocks, average morbidity rate was 25.9 per cent and mortality rate was 6.9 per cent. Antibiotic sensitivity testing was carried out using disc diffusion method on all isolates. Doxycycline showed maximum sensitivity followed by ceftriaxone, lincomycin and virginiamycin. It is concluded that, isolation of Clostridium perfringens was more in diseased birds than healthy birds and toxinotyping of isolates by PCR technique is sensitive and rapid.EnglishThesis