Author(s)

Shengfen Wang, Bing Zhao, Yuanyuan Song, Yang Zhou, Yu Pang, Xichao Ou, Qiang Li, Hui Xia, Yanlin Zhao

National Tuberculosis Reference Laboratory, National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.

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.

Rifampicin; Resistance; Beijing Genotype

Wang, S. , Zhao, B. , Song, Y. , Zhou, Y. , Pang, Y. , Ou, X. , Li, Q. , Xia, H. and Zhao, Y. (2013) Molecular characterization of the rpoB gene mutations of Mycobacterium tuberculosis isolated from China. Journal of Tuberculosis Research, 1, 1-8. doi: 10.4236/jtr.2013.11001.