The novel gene mtb192 is a candidate marker for the detection of multidrug-resistant Mycobacterium tuberculosis strains.

BACKGROUND: Multi-drug resistant tuberculosis (TB) is one of the most main threats to the global TB control work at present. And it's very difficult to detect. From a screen of differentially expressed genes in multidrug-resistant tuberculosis (MDR-TB) strains, we identified a new gene, mtb192. In the present study, we verified the association of mtb192 with TB drug resistance by detecting its expression in clinical isolates from paediatric TB patients.

MATERIALS AND METHODS: The homology of mtb192 was analysed by gene blasting in GenBank. The drug resistance of clinical TB isolates was tested, and mtb192 gene expression was compared using reverse transcription polymerase chain reaction (RT-PCR) and quantitative PCR.

RESULTS: Gene homology suggested that mtb192 is a new gene sequence. Among the 120 clinical isolates, 14 were positive for mtb192, including 12 in the MDR group, 2 in the single drug-resistant group, 1 in the poly-resistant group, and 1 in the sensitive group. The mtb192 positive expression rate was significantly higher in the MDR group than all other groups, and the mtb192 mRNA expression level was significantly higher in the MDR group than in the non-MDR group.

CONCLUSIONS: The new gene mtb192 showed significantly higher expression in MDR-TB strains and could be related to the development of MDR in Mycobacterium tuberculosis, highlighting it as a new genetic marker in the detection of MDR-TB.