[Frontiers in Bioscience 3, d525-531, June 8, 1998] |
MECHANISM OF MYCOBACTERIUM AVIUM COMPLEX PATHOGENESIS
Department of Medicine, University of Illinois at Chicago, Rm 864, M/C 735, 808 S.Wood st., Chicago, IL 60612
Received 5/4/98 Accepted 5/8/98
Infection may be considered as persistence and multiplication of a pathogen within the host, whereas significant damage to the host due to infection is considered as disease. A parasite to be successful, has to gain access to the host, colonize the host's tissue microenvironment and invade the tissues by overcoming protective mechanisms of the host. Normally, the host has innate as well as acquired mechanisms of prevention of colonization, by eliminating those microorganisms that gain access to different parts of the body. Gaining foot-hold in the host's tissues is an important prerequisite for invasion. To achieve these ends, the parasite devises various means to overcome protective barriers and undermines host's killing mechanisms. The parasite evades or subverts the host's surveillance mechanisms operating at various levels by producing different virulence factors. Opportunistic pathogens on the other hand, with inadequate virulence mechanisms, cause infections in immunodeficient individuals.