TITLE:
Molecular characterization of the rpoB gene mutations of Mycobacterium tuberculosis isolated from China
AUTHORS:
Shengfen Wang, Bing Zhao, Yuanyuan Song, Yang Zhou, Yu Pang, Xichao Ou, Qiang Li, Hui Xia, Yanlin Zhao
KEYWORDS:
Rifampicin; Resistance; Beijing Genotype
JOURNAL NAME:
Journal of Tuberculosis Research,
Vol.1 No.1,
June
20,
2013
ABSTRACT: Objective: To analyze characterization of the rpoBgene mutations of Mycobacterium tuber- culosis isolated from China and to explore the association of specific mutations conferring rifampicin (RIF) resistance with Beijing genotype strains. Methods: Genotypic analysis of 3479M. tuberculosis isolatesincluding 402 RIF-resistantand 3077 RIF-susceptible isolated from the na- tional drug-resistant tuberculosis baseline survey was performed. Results: DNA sequencing analysis of the 81-bp RIF resistance determining region (RRDR) of the ropB
gene revealed that 98.01% of RIF-resistant strains showedrpoBgene mutation, isolates with mutations at codon rpoB531, rpoB 526 and rpoB 516 were the most frequently. Analysis of the rpoB gene of 3077 RIF-susceptible strains revealed that 98.96% of the strains had no
mutation. The distribution of mutation frequency at differentcritical codons in different regions of China was statistically significant (p = 0.001). There was no significant difference in the occurrence of mutations at critical codons between the rifampicin-resistant Bei-jing and non-Beijing isolates.Conclusion: About 98% of RIF-resistant strains isolated from China carry mutations in RRDR ofrpoB gene.Mutation profiles in RIF-resistantM. tuberculosis clinical isolates are variable depending on the different geographical regionsof China. The results provide valuable information in adopting new molecular methods for diagnosis of TB in China.