Species identification of 267 Mycobacterium clinical isolates in Sichuan province by multi-locus PCR

Objective To understand the species of Mycobacteria isolated from TB patients in Sichuan. Methods Multi-locus PCR was conducted to amplify 7 specific DNA fragments of 16S rRNA, Rv0577, IS1561, Rv1510, Rv1970, Rv3877/8 and Rv3120 in the genome of 267 Mycobacterium strains which had been identified by PNB/TCH previously. Their species were verified by PRA-rpoB. identification and hsp65 sequencing. Results The multi-locus PCR results showed that 262 strains belonged to Mycobacterium tuberculosis complex (MTBC), 3 belonged to Mycobacterium africanum type Ⅰ and 2 were non-tuberculosis mycobacterium (NTM) strains, and by PRA-rpoB identification and hsp65 sequencing, 2 NTM strains were Mycobacterium avium and Mycobacterium septicum respectively While PNB/TCH result showed that 266 strains belonged to MTBC, 1 was NTM. The result of multi-locus PCR was consistent with that of rpoB-PRA identification and hsp65. sequencing Conclusion Multi-locus PCR is a rapid and effective method for the species identification of Mycobacterium and can be used in molecular epidemiology research and clinical diagnosis.