耐多药结核分枝杆菌基因突变分析

目的对临床分离的耐多药结核分枝杆菌株进行基因突变分析。方法对耐多药结核分枝杆菌临床分离菌株进行耐药基因的PCR检测，利用基因序列测定方法分析耐药基因突变情况。结果从耐多药结核病（MDR-TB）患者临床分离菌株中快速检测到rpoB、katG、rpsL、embB基因及其突变。耐多药菌株、全耐及单耐利福平分离菌株均检测rpoB基因点突变，突变位点主要为第516、526和531常见密码子，1例MDR-TB出现第479位和第531位密码子同时突变。耐多药菌、全耐菌及单耐异烟肼的菌株均检测有katG基因点突变，突变位点均为第2066位碱基C突变为Go全耐菌和对乙胺丁醇（EMB）耐药的耐多药菌株均检测有embB基因点突变，突变位点均为第306位密码子ATG突变为ACG。全耐菌和对链霉素（SM）耐药的MDR-TB菌株均检测有rpsL基因点突变，突变密码子为CCT突变为CTT，其中从1株对SM敏感的MDR-TB中也检测到突变。全敏感株、标准株及利福平（RIF）、异烟肼（INH）或EMB敏感的耐药株均无rpoB、katG或embB基因突变。结论PCR及基因序列测定可快速检测耐多药结核基因，结核分枝杆菌耐多药性与多个基因突变相关。

Gene mutation analysis of multidrug-resistant Mycobacterium tuberculosis

Objective To analyze the mutation of multidrug-resistant Mycobacterium tuberculosis gene from clinical isolates. Methods Multidrug-resistant M. tuberculosis genes of clinical isolates were detected by polymerase chain reaction. Gene mutation was analyzed by gene sequence detection. Results rpoB,katG,rpsL or embB gene and their mutation of M. tuberculosis from clinical isolates of muhidrug-resistant tuberculosis patients were rapidly detected. Spot mutation was found from multidrug-resistant, all drug-resistant and single rifampin（RIF）-resistant isolates in M. tuberculosis strains. Codon 531, 516 and 526 had higher mutational frequency in our RIF-resistant isolates. One multidrug-resistant i- solate presented a double mutation at two eodons, 531 and 479. Spot mutation was also detected from multidrug-resistant, all drugs-resistant or single INH-resistant strains in M. tuberculosis strains. Nucleotide C at 2 066 was mutated to G. Spot mutation was detected from multidrug-resistance including EMB resistance or all drugs-resistant strain of M. tuber-culosis strains. ATG at Codon 306 was mutated to ACG. Spot mutation was found from all drugs-resistant strains and multidrug-resistant strains of M. tuberculosis strains including SM-resistance. Codon CCT was mutated to eodon CTT. Spot mutation from one multidrug resistant but a SM susceptible isolate strain was meanwhile detected. No mutation of rpoB, katG, or embB in standard strains, all drugs-susceptible isolates, EMB/INH/RIF susceptible isolates was detected. Conclusion MDR-TB could be rapidly diagnosed by polymerase chain reaction. Multidrug-resistance to M. tubercu-losis strains was related with the mutation of multiple genes.