安顺地区结核分枝杆菌基因分型及耐药性分析

Genotyping and drug resistance analysis of Mycobacterium tuberculosis in Anshun region

目的研究贵州省安顺地区结核分枝杆菌(MTB)主要基因分型及耐药性。方法采用RD105基因缺失法和双重PCR法对安顺地区152株MTB临床分离株进行基因分型、药物敏感试验分析耐药性,采用基因测序技术对北京型MTB利福平耐药基因RNA聚合酶β亚基(rpoB)进行测序。结果152株MTB中,122株(80.26%)为北京型、30株(19.74%)为非北京型;108株MTB对抗结核药物敏感,44株对16种抗结核药物耐药,总耐药率为28.95%;44株MTB耐药菌株中31例对利福平耐药,占70.45%,北京型MTB对利福平耐药率显著高于非北京型(χ^(2)=6.896,P=0.009),非利福平耐药结核菌株共13株、占耐药结核菌株的29.55%;北京型MTB利福平耐药rpoB基因测序结果表明,相关位点突变共15株,其中最显著的突变位点是rpoB450、为Ser450Leu,共7株(7/15,46.67%)。结论贵州省安顺地区MTB主要为北京型,主要对利福平耐药,耐药基因rpoB的突变位点为Ser450Leu。

Objective To study the main genotypes distribution and drug resistance of Mycobacterium tuberculosis(MTB)in Anshun region in Guizhou province.Methods RD105 gene deletion and duplex PCR were used to genotype 152 strain MTB clinical isolates of in Anshun region.Drug resistance was analyzed by drug sensitivity test.Gene sequencing technique was used to sequence RNA polymeraseβsubunit(rpoB),an indicator of Beijing rifampicin resistant MTB.Results Among 152 strain MTB isolates,there were 122 strains with Beijing genotype(80.26%)and 30 strains with non-Beijing genotype(19.74%).There were 108 strains sensitive to anti-tuberculosis drugs and 44 strains resistant to 16 anti-tuberculosis drugs.Among 44 MTB resistant strains,31 strains were resistant to rifampicin,accounting for 70.45%.Beijing genotype MTB had a significantly higher resistance rate to rifampicin than non-Beijing genotype MTB(χ^(2)=6.896,P=0.009).There were 13 non-rifampicin resistant tuberculosis strains,accounting for 29.55% of the drug-resistant tuberculosis strains.The sequencing results of the rpoB gene for rifampicin resistance in Beijing genotype MTB showed that there were 15 strains with relevant site mutations in rpoB,among which,7 stains had the most significant mutation site was Ser450Leu in rpoB,accounting for 46.67%(7/15).Conclusions The prevalent genotype of MTB in Anshun region is Beijing genotype.The main drug-resistance type is rifampicin resistance.The mutation site of the resistance gene rpoB is Ser450Leu.