2017-2019年贵州省结核分枝杆菌多位点序列分析及与耐药的相关性

目的了解贵州省2017-2019年结核分枝杆菌分离株的等位基因型别特征及其与耐药的相关性,为贵州省结核病的防治提供科学依据。方法收集贵州省毕节市、安顺市、仁怀市和威宁县4个国家级结核病耐药监测点2017-2019年分离的52株结核分枝杆菌,采用基于7个管家基因位点(recX、rpsl、rmlC、rpmG1、mprA、gcvH、ideR)的MLSA技术进行ST分型。选用异烟肼(INH)、链霉素(SM)、乙胺丁醇(EMB)、利福平(RFP)、卡那霉素(KAM)和氧氟沙星(OFX)6种抗结核药物对52株结核分枝杆菌进行药敏试验,分析菌株耐药与ST型别的相关性。结果52株结核分枝杆菌经MLSA分为11个ST型,其中优势ST型为ST11型(占32.7%)、ST1(占23.1%)和ST5型(占15.4%)。药敏试验显示,52株结核分枝杆菌总耐药率为42.3%(22/52),其中单耐药率为15.4%(8/52),耐多药率为19.2%(10/52),多耐药率为3.8%(2/52)。基于7个管家基因位点的聚类分析和最小间距图分析结果显示,ST2、ST4和ST6型菌株全部为敏感菌株,ST7和ST8型菌株均为多耐药菌株,ST9型菌株均为耐多药菌株,其余ST型由耐药和敏感菌株构成。结论贵州省2017-2019年结核分枝杆菌以ST11、ST1和ST5型为主,ST型呈现多样性。菌株以单耐药和耐多药为主,ST型与耐药具有一定的相关性。

Multilocus sequence genotyping and drug resistance analysis of Mycobacterium tuberculosis isolated in Guizhou province from 2017 to 2019

Objectives To use multilocus sequence analysis(MLSA)to genotype Mycobacterium tuberculosis strains isolated in Guizhou Province from 2017 to 2019 to understand its characteristics by genotype and its relationship to drug resistance in order to provide a scientific basis for the prevention,control,and treatment of tuberculosis.Methods Fifty-two isolates of M.tuberculosis were collected from 4 national drug-resistant TB monitoring sites distributed in Bijie,Anshun,Renhuai,and Weining in Guizhou Province from 2017 to 2019.MLSA based on 7 house-keeping gene loci(recX,rpsl,rmlC,rpmG1,mprA,gcvH,and ideR)was used to genotype selected M.tuberculosis strains.In order to further understand the drug resistance of the M.tuberculosis strains,isoniazid(INH),streptomycin(SM),ethambutol(EMB),rifampicin(RFP),kanamycin(KAM),and ofloxacin(OFX)were used in a drug sensitivity test and the correlation between the drug resistance and STs were analyzed.Results According to MLSA analysis,52 strains were divided into 11 STs,and the dominant STs were ST11(32.7%),ST1(23.1%),and ST5(15.4%).The drug sensitivity test indicated that the 52 strains of M.tuberculosis had an overall resistance of 42.3%(22/52);15.4%of strains(8/52)had single drug resistance,19.2%(10/52)had extensive drug resistance,and 3.8%(2/52)had multi-drug resistance.Cluster analysis and minimum spanning tree analysis based on the 7 housekeeping gene loci indicated that all of the ST2,ST4,and ST6 strains were sensitive to the selected drugs,while all of the ST7 and ST8 strains were extensively drug-resistant,and ST9 strains were multidrug-resistant.The rest of the ST strains consisted of drug-resistant and sensitive strains.Conclusion The ST diversity of M.tuberculosis in Guizhou from 2017 to 2019 has been revealed.ST11,ST1,and ST5 were the dominant STs.The resistant strains were mainly resistant to a single drug or extensively drug-resistant.There is some correlation between STs and drug resistance.