Tuberculosis in Cattle (M. caprae) in the Years 2009-2014: Pathomorphology and Histological Demonstration of Mycobacteria in Bovine Tuberculosis

Several outbreaks of bovine tuberculosis, caused by M. caprae, occurred in the years between 2009 and 2014 in some cattle flocks of Bavaria, Germany. The suspected cattle were investigated in context of the regulations of Germany. Following the culling, tissue samples including lung, liver, small intestine, their regional lymph nodes, and retropharyngeal lymph node were collected from 84 cattle for the further bacteriological and pathomorphological investigations. The organs were evaluated macroscopically and light microscopically. Furthermore, mycobacteria and mycobacterial antigens were demonstrated using acid-fast staining and immunohistochemistry, respectively. The ultrastructural demonstration of bacteria was carried out using semi-thin sections, in which the mycobacterial antigens were demonstrated by postembedding-immunohistochemistry.