贵州省结核分枝杆菌临床分离株的基因分型及耐药性分析

Genotyping and analysis of the drug resistance of clinical isolates of Mycobacterium tuberculosis in Guizhou

目的了解贵州省结核分枝杆菌临床分离株的基因分型及耐药情况。方法收集2014年贵州省结核分枝杆菌临床分离株260株,采用比例法进行药敏试验;以16SrRNA基因和MTP40基因为对照,通过PCR检测RD105基因进行北京型鉴定;采用NTF分析法对北京家族菌株进行古典型和现代型分型。结果 260株结核分枝杆菌临床分离株中北京家族菌株259株（99.6%）,非北京家族菌株1株（0.4%）,其中北京家族古代型占96.9%（251/259）,现代型占3.1%（8/259）。北京家族菌株古代型对异烟肼、利福平、链霉素和乙胺丁醇的耐药率分别为33.9%、30.3%、31.8%和21.1%,耐多药率为29.5%;北京家族菌株现代型未检出耐多药菌株,与北京家族菌株古代型的耐多药率比较,差异有统计学意义（χ~2=14.07,P〈0.05）。结论贵州省结核分枝杆菌主要流行株为北京家族古代型,北京家族古代型耐多药率高于现代型。

Objectives To genotype Mycobacterium tuberculosis isolated in Guizhou Province and to ascertain its drug resistance. Methods Two hundred and sixty strains of M.tuberculosis were isolated in Guizhou Province in 2014.Drug susceptibility was determined by the proportion method,and strains with the Beijing genotype were identified using an RD105 deletion test.Ancient and modern subtypes were subdivided on the basis of NTF locus analysis. Results Of the isolates,259（99.6%）were identified as the Beijing genotype while 1（0.4%）were identified as some other genotype.Of the 259 isolates that were the Beijing genotype,96.9%（251/259）were the ancient subtype and 3.1%（8/259）were the modern subtype.Strains of the Beijing genotype had resistance to isoniazid of 33.9%,resistance to rifampin of 30.3%,resistance to streptomycin of 31.8%,and resistance to ethambutol of 21.1%.Only 1strain of the modern Beijing genotype was resistant to ethambutol,and the other 7strains were all susceptible to the four anti-tuberculosis drugs.Strains of the ancient Beijing genotype had multidrug resistance（MDR）of 29.5%.There were no multidrug-resistant strains among the strains of the modern Beijing genotype,and the MDR of the strains of the modern Beijing genotype differed significantly from that of the strains of the ancient Beijing genotype（χ~2=14.07,P〈0.05）. Conclusion Strains of M.tuberculosis that were prevalent in Guizhou Province were the ancient Beijing genotype.Strains of the ancient Beijing genotype had a higher level of MDR than did strains of the modern Beijing genotype.