Clinical significance of mycobacterial genotyping in Mycobacterium avium lung disease in Korea.

SETTING:A recent study in Japan found that mycobacterial genotyping was associated with disease progression and susceptibility to certain drugs in Mycobacterium avium lung disease. However, it is not known whether this association is true in other populations. OBJECTIVE:To investigate the association between mycobacterial genotype, clinical characteristics and the progression of M. avium lung disease in Korean patients. DESIGN:A total of 102 M. avium clinical isolates were genotyped using M. avium tandem repeats-variable number of tandem repeats (MATR-VNTR). RESULTS:MATR-VNTR typing demonstrated a high discriminatory power and genetic diversity for molecular epidemiological studies of M. avium. In the phylogenetic tree, the M. avium clinical isolates were divided into three major clusters: A, B and C. Cluster A was observed most frequently (64/102, 63%), whereas cluster C was found in a minor proportion of the isolates (8/102, 8%). However, there was no association between the clinical characteristics, disease progression and drug susceptibility and the phylogenetic tree based on VNTR genotyping. CONCLUSIONS:MATR-VNTR genotyping may be useful for epidemiological studies of M. avium lung disease; however, no association was found between the specific VNTR genotypes of M. avium and the clinical characteristics of Korean patients.