Diagnosis of bovine tuberculosis by immunohistochemistry and polymerase chain reaction-restriction fragment length poly-morphism

Bovine tuberculosis is a chronic, contagious, granulomatous disease of domestic as well as wild animals, caused by the member of Mycobacterium tuberculosis complex. The present study was carried out to diagnose bovine tuberculosis using Ziehl-Neelsen Staining, Histopathology, Immunohistochemistry and Polymerase Chain Reaction-Restriction Fragment Length Polymorphism. Twenty lung samples from animals suspected for tuberculosis were collected for the study. Grossly, circumscribed yellowish white calcified lesions of various sizes were observed and acid-fast bacilli were revealed in thirteen impression smears. Histopathologi- cally, the lung section showed tuberculous granulomatous lesions characterised by well-demarcated, multifocal areas of caseous necrosis with calcification and circumscribed fibrous encapsulation along with mononuclear cells. Immunohistochemically, Mycobacterium tuberculosis antigens were detected in the eleven lung granulomas and thereby diagnosed as bovine tuberculosis. Further the causative agent was confirmed as M. bovis by PCR-RFLP.