中国天津耐多药北京家族分枝杆菌分离株的分子特征。

Molecular characterization of drug-resistant Beijing family isolates of Mycobacterium tuberculosis from Tianjin, China.

机构信息

Tianjin Medical University, Tianjin, China.

出版信息

Biomed Environ Sci. 2010 Jun;23(3):188-93. doi: 10.1016/S0895-3988(10)60051-7.

DOI:10.1016/S0895-3988(10)60051-7

PMID:20708497

Abstract

OBJECTIVE

Tuberculosis remains a severe public health issue, and the Beijing family of mycobacterium tuberculosis (M. tuberculosis) is widespread in East Asia, especially in some areas in China, like Beijing and Tianjin. This study aimed at determining the mutation patterns of drug-resistant Beijing strains of M. tuberculosis isolated from Tianjin, China.

METHODS

A total of 822 M. tuberculosis isolates were screened for drug resistance by an absolute concentration method and the genotype was identified by PCR. 169 drug-resistant isolates of the Beijing family were analyzed for the potential mutations in the rpoB, katG, inhA promoter region and in rpsL, rrs and embB genes, which are associated with resistance to rifampin (RFP), isoniazid (INH), streptomycin (SM) and ethambutol (EMB) respectively by PCR and DNA sequencing.

RESULTS

Fifty-eight out of 63 RFP-resistant isolates were found to carry the mutations within the 81-bp RFP resistance determining region (RRDR) of the rpoB gene and the most frequent mutations occurred at codon 531 (44.4%), 526 (28.6%), and 516 (7.9%) respectively. 16 mutation patterns affecting 12 different codons around the RRDR of rpoB were found. Of 116 INH-resistant isolates, 56 (48.3%) had the mutation of katG 315 (AGC-->ACC) (Ser-->Thr), 3 (2.6%) carried S315N (AGC-->AAC) and 27 (16.0%) had the mutation of inhA-15A-->T. 84 out of 122 SM-resistant isolates (68.9%) displayed mutations at the codons 43 or 88 with AAG-->AGG (Lys-->Arg) of the rpsL gene and 22 (18.0%) with the mutations at positions 513A-->C, 516C-->T or 905 A-->G in the rrs gene. Of 34 EMB-resistant isolates, 6 had mutation with M306V (ATG-->GTG), 3 with M306I (ATG-->ATT), 1 with M306I (ATG-->ATA), 1 with D328Y (GAT-->TAT), 1 with V348L (GTC-->CTC), and 1 with G406S (GGC-->AGC) in the embB gene.

CONCLUSION

These novel findings extended our understanding of resistance-related mutations in the Beijing strains of M. tuberculosis and may provide a scientific basis for development of new strategies for diagnosis and control of tuberculosis in China and other countries where Beijing strains are prevalent.

摘要

目的

结核病仍是一个严重的公共卫生问题，北京家族分枝杆菌（M. tuberculosis）广泛存在于东亚，尤其是在中国的一些地区，如北京和天津。本研究旨在确定从中国天津分离的耐多药北京家族分枝杆菌的突变模式。

方法

采用绝对浓度法对 822 株分枝杆菌进行耐药性筛选，采用 PCR 法鉴定基因型。对 169 株北京家族耐多药株进行 rpoB、katG、inhA 启动子区和 rpsL、rrs 和 embB 基因的潜在突变分析，这些基因分别与利福平（RFP）、异烟肼（INH）、链霉素（SM）和乙胺丁醇（EMB）的耐药性相关，采用 PCR 和 DNA 测序法进行分析。

结果

63 株 RFP 耐药株中，58 株发现 rpoB 基因 81bp RFP 耐药决定区（RRDR）内存在突变，最常见的突变发生在密码子 531（44.4%）、526（28.6%）和 516（7.9%）。在 rpoB 的 RRDR 周围的 12 个不同密码子中发现了 16 种影响模式。在 116 株 INH 耐药株中，56 株（48.3%）存在 katG 315（AGC-->ACC）（Ser-->Thr）突变，3 株（2.6%）存在 S315N（AGC-->AAC）突变，27 株（16.0%）存在 inhA-15A-->T 突变。122 株 SM 耐药株中，84 株（68.9%）在 rpsL 基因的密码子 43 或 88 处出现 AAG-->AGG（Lys-->Arg）突变，22 株（18.0%）在 rrs 基因的 513A-->C、516C-->T 或 905A-->G 处发生突变。在 34 株 EMB 耐药株中，有 6 株存在 M306V（ATG-->GTG）突变，3 株存在 M306I（ATG-->ATT）突变，1 株存在 M306I（ATG-->ATA）突变，1 株存在 D328Y（GAT-->TAT）突变，1 株存在 V348L（GTC-->CTC）突变，1 株存在 G406S（GGC-->AGC）突变。