Studies on the prevention of tuberculosis in pet dogs 1. The effects of BCG pretreatment in pet dogs inoculated experimentally with Mycobacterium bovis

Kang, Jong-koo; Kim, Chang-ki

Korean Journal of Veterinary Research 1992;32(1):117-125.

Jong-koo Kang, Chang-ki Kim

Department of Veterinary Medicine, College of Agriculture Chung-Buk National University

애완견의 결핵예방에 관한 연구 1. Mycobacterium bovis를 실험적으로 접종한 애완견에 있어서 BCG의 전처치 효과

강종구, 김창기

충북대학교 농과대학 수의학과

Abstract

Dogs were divided into 3 groups of two each; Bacillie Calmette-Guerin(BCG) pretreatment, M bovis only treatment and uninfected control group. BCG were vaccinated intradermally with 0.2ml before 3weeks of M bovis intraperitoneal infection. Infection at necropsy 4months later was readily in the both treated dogs. Histopathologically, the BCG pretreated dogs produce the moderate accumulation of macrophages and focal granuloma formation in the lung, whereas the M bovis only treared dogs produce the accumulation of predominantly macrophages, occasionaly polymorphonuclear cells and the more larger granuloma Bronchoalveolar lavage(BAL) was obtained and total and differential cell counts were examined. Total number of BAL cells harvested from uninfected dogs is lower compared with those of the both treated groups. The total cell number of M bovis only treated dogs were singificantly higher 1.8 times than that of the BCG pretreated dogs. The Fe receptor activity and the growth of organism in alveolar macrophages obtained from BCG pretreated dogs were compared with that in macrophages from M bovis only treated dogs. BCG vaccination resulted in substantial macrophage activation, measured as increased Fc receptor mediated phagocytosis and rosette formation, as wells as the inhibition of intracellular mycobacteria multiplication. However, actibated macrophages taken from BCG pretreated dogs are incapable of killing the M bovis. Thus, these results suggest that BCG pretrearment in the dog may produce a protective effect against tuberculosis because active alveolar macrophages have acquired antituberculous immunity, although few mycobacteria within the lung remain in a metabolically active state.

Key Words: BCG, M bovis, alveolar macrophages, Fc receptor activity, protective effect