Journal of medical microbiology
-
The Mycobacterium avium complex (MAC) is the most frequently isolated species among non-tuberculous mycobacteria (NTM) clinical isolates. Physicians pay attention to the differential diagnosis of the disease caused by MAC from tuberculosis because of their similar clinical presentations. Expression of the macrophage-induced gene (mig) is one of the virulence phenotypes in MAC, but it has not been determined whether the presence of the mig gene itself has any relationship with clinical disease or whether it is merely a marker for MAC. ⋯ The mig PCR results were 100 % positive for the MAC isolates studied, irrespective of their species, sequevar or disease-causing properties. However, following bootstrap analysis of the mig sequences, we observed definite grouping between M. avium and M. intracellulare. Thus the mig gene is a species-specific marker with distinct sequence diversity between the two species M. avium and M. intracellulare, but there is poor correlation between disease-causing properties and specific mig sequences.