Mycobacterium bovis Infection in a Farmed Elk in Korea

A case of tuberculosis is reported in an eight-year-old, male, elk (Cervus elaphus nelsoni). The elk showed severe coughing, respiratory distress, abdominal breathing, anorexia, and severe progressive emaciation in the elk farm. At necropsy, the elk appeared in poor body condition. Mild enlargement of retropharyngeal and submandibular lymph node was observed in the head. Diffuse fibrinous pleuritis and purple red lobar pneumonia were found in the thorax. Well demarcated numerous dark yellow discrete or confluent nodules from 0.3 to 2 cm in diameter were scattered in the whole lung. Bronchial and mediastinal lymph nodes were also enlarged. Histopathologically, lungs had typical classical tuberculous granulomas, multiple abscesses, and numerous macrophages and Langhans giant cells infiltration in alveolar lumen. In the lymph nodes, there were small clusters of necrosis and infiltration of numerous macrophages, epithelioid cells, and Langhans giant cells. With the acid-fast staining, numerous mycobacteria were revealed in the lung and lymph nodes. According to this study, there are differences of the histopathologic lesions and the numbers of acid-fast bacilli in the lesions between this elk and cattle. Mycobacterium bovis was confirmed as a causative agent in this elk using bacterial isolation, biochemical characteristics, and PCR technique. The isolate was negative for niacin test, nitrate reductase, and pyrazinamidase. This is a first report for bovine tuberculosis of farmed elk in Asia.

Phenotypic and functional analysis of bovine gammadelta lymphocytes

The studies have provided the first comprehensive comparison of the factors regulating activation and proliferation of WC1+ and WC1- gammadelta T cells. The investigation has shown that accessory molecules essential for activation and function of WC1+ and WC1- gammadelta T cells and the sources and roles of cytokines in activation of gammadelta T cells through the T cell receptor (TCR). The study has also shown that the role of cytokines in activation and function of gammadelta T cells activated indirectly through cytokines secreted by ab T cells, accessory cells and antigen presenting cells (APC). Cytokines were differentially produced by subpopulations of gammadelta T cells under different conditions of activation. The investigation obtained in this study has revealed that factors account for activation and proliferation of gammadelta T cells in cultures designed to study MHC-restricted responses to antigens. Evidence obtained here has shown there is biological relevance to activation under these culture conditions that points to potential regulatory and effector functions of gammadelta T cells. The investigations have also provided the information needed to begin identifying and characterizing antigens recognized by the TCR repertoires of WC1+ and WC1- gammadelta T cells. Finally, the investigations have provided the information needed to begin analysis of the mechanisms by which gammadelta T cells modulate MHC restricted immune responses to pathogens and derived vaccines.