The African Tuberculosis Situation including Mycobacteria outside the TB complex species

摘要

The mycobacteria are a group of microorganisms of over 130 species(1). Commonly encountered in the environment (2-4), some are obligate pathogens, some are opportunistic pathogens, and some are not known to be pathogenic. Environmental niches includewater, soil, protozoans, domestic and wild animals, invertebrates, milk and food products. They can be grouped into a number of basic types, depending on what criteria are used: for example, the fast growing species are usually not pathogenic, whilst slow growers are. Alternatively one may classify them into the MTBC group (Mycobacterium tuberculosis complex, which includes M tuberculosis, M bovis, BCG, M canettii, M africanum, M pinnipedii, M microti, M caprae, the dassie and the oryx bacillus, and therecently discovered M mungi (5)) (see fig 1) and "the rest" or non-tuberculous mycobacteria (NTM). This does not imply that NTMs cannot cause TB-like disease however.