MPT64 gene mutation of MPT64-negative mycobacterium tuberculosis in Guangdong

Abstract

Objective To investigate the characteristics of mpt64 gene mutation of MPT64-negative mycobacterium tuberculosis in Guangdong. Methods 17 MPT64-negative and 186 MPT64-positive clinical isolates of mycobacterium tuberculosis which were stored in Mycobacterium Strain Culture Collection of Guangzhou District were cultured and proliferated. The genes of mpt64 were sequenced and analyzed. Results Mutations were found in 16 MPT64-negative strains; among which, 14 got 63-bp deletion at 196-258, 1 had a single nucleotide substitution of G to C at 173, and another strain had a nucleotide of A insertion at 353 meanwhile. 4 MPT64-positive strains had point substitution mutations, such as C to G at 323, G to A at 127, C to A at 477, and C to T at 654. Conclusion The deletion of 196-258 bases of mpt64 gene may be the molecular mechanism for mycobacterium tuberculosis of non-MPT64 secretory in Guangdong. Key words: Pulmonary tuberculosis; Mycobacterium tuberculosis; MPT64; Gene mutation