Identification of clinical Mycobacterium isolates in Zigong, Sichuan province, 2011–2018

ObjectiveTo investigate Mycobacterial species characteristics of pulmonary Mycobacterium infection in Zigong, Sichuan province, China for providing a scientific basis of the clinical diagnosis and treatment, and effective control strategy of Mycobacterial diseases.

MethodsThe of acid-fast stain positive cultures collected from clinical patients suspected with pulmonary tuberculosis from 2011 to 2018 were identified to Mycobacterium tuberculosis (MTB) and nontuberculosis Mycobacterium (NTM) by differential culture method with Nitrobenzene acid(PNB) and Thiophene -2- carboxylic acid hydrazine (TCH) (PNB/TCH method). Then, the strains of NTM were identified to species levelby multilocus sequence analysis (MLSA) with rpoB and hsp65 gene sequences.

ResultsA total of 2 751 clinical Mycobacterium isolates were collected and identified with PNB/TCH method and multi loci PCR, of which there were 2 647 strains (96.22%) of MTB, 32(1.16%) M. africanum Ⅰ, and 72(2.62%) NTM. A total of 11 species were identified from 72 NTM strains.

ConclusionThe vast majority of pulmonary Mycobacterial infectionwere caused by MTB and there were lots of pathogenic NTM species caused pulmonary infectious disearses, of which the majoring species is M. abscessus, M. intracellulare, M. kansasii and M. avium in Zigong.