title: Molecular characterization of drug-resistant mycobacterium tuberculosis isolates from Sichuan Province in china.
abstract: Tuberculosis is still a severe public health issue in eastern Asia, and Sichuan is the key area for tuberculosis control in China. To determine the phenotypic and mutation patterns of drug resistance in Mycobacterium tuberculosis isolates from Sichuan, the drug susceptibility of 198 clinical isolates was examined. Among these isolates, 76 drug-resistant and 20 susceptible isolates were analyzed for the rpoB, embB, and katG and inhA regulatory regions. These are mutations believed to associate with rifampin (RIF), ethambutol (EMB), and isoniazid (INH) resistance, respectively. Of the 60 RIF-resistant isolates, 54 (90.0%) carried mutations on the amplified fragment of the rpoB gene, and the most common one (64.8%, 35/54) was at codon 531. Two new mutation patterns were recognized: one isolate harbored three mutations at codons 511, 516, and 518, and the other carried the dual mutation GAChACC at codon 516. A total of 30 INH-resistant isolates (60.0%, 30/50) had mutations at codon 315, whereas 4 (8.0%) had mutations at the inhA regulatory region. Among the 46 EMB-resistant isolates, 22 harbored the Met306 mutation. The results showed geographical variation in the mutation types of drug-resistant genes in M. tuberculosis isolates from Sichuan; this finding is valuable for the development of targeted and rapid molecular diagnostic methods suitable for specific regions.
authors.affiliation: College of Life Sciences, Sichuan University, Sichuan, PR China.
authors.forename: J H
authors.initials: JH
authors.lastname: Guo
authors.forename: W L
authors.initials: WL
authors.lastname: Xiang
authors.forename: Q R
authors.initials: QR
authors.lastname: Zhao
authors.forename: T
authors.initials: T
authors.lastname: Luo
authors.forename: M
authors.initials: M
authors.lastname: Huang
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: J
authors.initials: J
authors.lastname: Zhao
authors.forename: Z R
authors.initials: ZR
authors.lastname: Yang
authors.forename: Q
authors.initials: Q
authors.lastname: Sun
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002374:Catalase / Q000235:genetics; D002681:China / Q000453:epidemiology; D003062:Codon / Q000235:genetics; D012321:DNA-Directed RNA Polymerases; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D010641:Phenotype; D012293:Rifampin / Q000494:pharmacology
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D003062:Codon; C505805:rpoB protein, Mycobacterium tuberculosis; D002374:Catalase; C480353:katG protein, Mycobacterium tuberculosis; D012321:DNA-Directed RNA Polymerases; D007538:Isoniazid; D012293:Rifampin