Non-tuberculous mycobacteria in China

Infection with non-tuberculous mycobacteria (NTM) is relatively rare in areas that are high-endemic for tuberculosis. We identified 126 strains of NTM in respiratory specimens collected by the Chinese Nationwide Survey in 2000, the Beijing Tuberculosis and Thoracic Tumour Institution, and the Guangzhou Thoracic Hospital. Species diagnosis was attained by sequencing of 16S-rDNA complemented by phenotypic characterization when necessary. Mycobacterium avium-intracellulare-complex - well known as a potential pulmonary pathogen - was diagnosed in all 3 surveys. Potentially pathogenic rapid growing strains of M. abscessus, M. chelonae and M. fortuitum were also detected. Moreover, species non-pathogenic in the airways such as M. nonchromogenicum, M. terrae and M. gordonae were encountered. Also, single strains of rare NTM species were isolated. Thus, several potentially pathogenic species of NTM were isolated from pulmonary specimens in China, and molecular techniques made possible exact species diagnosis.