Diagnosis of Marek’s Disease through Histological, Immunohisto-Chemical and Molecular Applications: A Comparative Study Reddy Y. Vishnu Prasanth, Kumar A. Anand*, Amaravathi P. Department of Veterinary Pathology, College of Veterinary ScienceSri Venkateswara Veterinary University, Tirupati-517502, Andhra Pradesh, India *Address for Correspondence, Dr A. Anand Kumar, Department of Veterinary Pathology, College of Veterinary Science, Sri Venkateswara Veterinary University, Tirupati-517502, Andhra Pradesh, India, E-mail: 7aakumar@gmail.com
Online Published on 07 December, 2022. Abstract A total of 615 dead birds from various commercial poultry farms in and around Tirupati of Chittoor district of Andhra Pradesh were examined and among them 63 birds (10.24%) revealed suspected lesions for Marek’s disease. The gross and microscopic examination of the different tissues was carried out and further confirmed as Marek’s disease by immunohistochemical and molecular applications. Histologically, infiltration of the pleomorphic lymphoid cells was observed in the liver, heart, lung, kidney, ovary, spleen, thymus, pancreas, proventriculus, intestine, skin, skeletal muscle and sciatic nerve. Immunohistochemical staining revealed mild to moderate positive reactivity for MDV antigens in the cytoplasm of the infiltrating lymphocytes in all the organs. Mild positive reactivity for Marek’s disease was detected in the hepatocytes, tubular epithelial cells of the kidney, myocardial fibers and epithelial cells of the intestine. Molecular detection of the Meq gene of serotype 1 MDV in the tissue samples revealed an expected size of 1081 bp in PCR products in Marek’s disease - positive birds. The sequence showed 99.7% homology with that of different strains of serotype-1 specific Gallid Herpes virus 2 of Kerala and Ludhiana. The above studies indicated that the incidence of Marek’s disease among the vaccinated chicken flock was evident. The immunohistochemical studies revealed the distribution pattern of the Marek’s disease virus in internal organs and the PCR product was amplified on histologically diagnosed tissues. Top Keywords Diagnosis, Histological, Immunohistochemical, Marek’s disease, PCR. Top |