Molecular characterization of Mycobacterium intracellulare-related strains based on the sequence analysis of hsp65, internal transcribed spacer and 16S rRNA genes

We investigated the molecular epidemiological features of 94 Mycobacterium intracellulare-related strains, isolated from Korean patients, using sequence analysis targeting 3 independent chronometer molecules, hsp65, the internal transcribed spacer 1 region and the 16S rRNA gene. By collective consideration of these three gene-based approaches, the 94 strains were divided into 5 groups (INT1, INT2, IN13, INT4 and INT5). The frequencies of genotype INT1, 2, 3, 4 and 5 in the 94 isolates were 57.4% (54), 27.7% (26), 6.4% (6), 5.3% (5) and 3.2% (3), respectively. When correlations between genotypes and clinical parameters (age, sex, radiological type and the presence of a cavity) were analysed in 78 patients with non-tuberculous mycobacteria pulmonary diseases, no relationships were observed with respect to age, sex and radiological type, but genotype and the presence of a cavity tended to be related (P=0.051).