IDENTIFICATION OF MYCOBACTERIUM SPECIES BY SEQUENCING METHODS

Objective: To discriminate and describe the prevalence between MTBC and NTM in the mycobacteria isolates at National Lung Hospital from the August of 2019 to the August of 2020, of which MPT64 cannot be detected by TBc ID. Methods: Identification mycobacteria isolates to the species level by analysis several target genes, including 16S rRNA, gyrB, rpoB, hsp65 and ITS. Results: Overall, there are 105 (100%) TBc ID negative strains, including 56 MTBC strains (53,3%) and 49 NTM strains (46,7%). Looking closely to species level identification, of all 56 MTBC strains, there are 55 M. tuberculosis strains (98,2%) and solely 1 M. bovis strains (1,8%). Within 49 NTM strains, the highest frequency is M. abscessus/ M. chelonae (27 strains- 55,1%), the second is MAC (8 strains- 16,3%) and other 13 NTM species take some small portions. Conclusion: Some strains of MTBC cannot be detected by TBc ID, including M. tuberculosis and M. bovis. The predominant NTM species related to pulmonary disease in Vietnam are M. abscessus/ M. chelonae and MAC. Keywords: Mycobacteria, MTBC, NTM, TBcID, sequencing