Pathology and molecular diagnosis of necrotic enteritis in chicken

The present research work was carried out with an aim to study the pathology of necrotic enteritis in chickens followed by isolation and molecular detection of C. perfringens. Total 320 numbers of samples were collected from 15 districts in Assam. Isolation and identification of C. perfringens by cultural, morphological characteristics and confirmation was done by detection of cpa gene of C. perfringens by PCR with virulence toxin genes of C. perfringens such as TpeL and NetB. The clinical signs shown by the birds were diarrhoea, dehydration, depression, reluctance to move, loss of appetite, ruffled feathers, drooping of wings and head and huddling. The gross lesions of intestine revealed haemorrhagic, eroded, detached dead mucosal tissues, diphtheritic membrane, and distention. Liver, kidneys and lungs showed congestion, haemorrhage and focal areas of necrosis. Histopathology of NE in chickens revealed congestion of blood vessels in the lamina propria and submucosa with vacuolation of epithelial cells of intestinal villi with necrosis, making the villi broader and shorter. Different developmental stages of coccidia were also seen in the mucosal epithelial cells in few birds during this study. Liver, kidneys, heart, lungs, spleen, bursa of Fabricius and brain showed variable nature of histopathological lesions like congestion, haemorrhage and focal areas of coagulative necrosis.