甘肃省临床分离结核分枝杆菌MLVA分型初步研究

目的随机选取2005-2007年间甘肃省肺科医院临床分离结核分枝杆菌菌株,通过多位点可变数目串联重复序列(Multiple locus variable numbers of tandemrepeats analysis,MLVA)分型,了解甘肃结核分枝杆菌流行菌株基因型情况。方法选择标化的15个VNTR位点,对临床分离菌株DNA进行检测,DNA指纹图谱使用Bio Numerics4.5软件进行统计分析,得出聚类分析结果。结果 228株结核分枝杆菌被分为4大基因群,7个大基因类型,分别包含13(5.7%)、3(1.3%)、7(3.1%)、1(0.4%)、171(75%)、31(13.6%)、2(0.9%)个株菌;在株水平基因分型上,93(40.8%)株为单菌株基因型;其余菌株基因型分别包含2-10株结核分枝杆菌,共构成132个基因簇。结论甘肃结核分枝杆菌菌株存在丰富的基因多态性,ML-VA方法具有较高的基因分型能力,可以满足结核分枝杆菌株水平DNA分型的需要。甘肃省结核分枝杆菌流行株主要为北京家族基因型菌株。

Characterization of Mycobacterium tuberculosis isolates from patients in Gansu by multiple locus variable numbers of tandem repeats

To analyze the genotype of epidemic Mycobacterium tuberculosis strains by multiple-locus variable-number tandem repeat analysis（MLVA）in Gansu from 2004 to 2006,15 standardized VNTR loci were selected to type the clinical isolated M.tuberculosis strains.Results were analyzed by BioNumerics 4.5 and the dendrogram was summarized from finger printings.Result of MLVA showed that the 228 strains of M.tuberculosis were classified into 4 major genetic groups and 7 main genotypes,which including strains of 13（5.7%）,3（1.3%）,7（3.1%）,1（0.4%）,171（75%）,31（13.6%）and 2（0.9%）,respectively.Furtherly,228 strains were divided into 132 geno-clusters,among which there were 93 strains belonged to unique genotype.Results indicate that the bacterial strains of M.tb in Gansu are rich in genetic polymorphism and MLVA is very useful for typing the genotype of M.tuberculosis strains.Beijing family was the dominant genotype in Gansu.