不同可变数目串联重复序列组合鉴定结核分枝杆菌临床菌株分型的效果

摘要

Objective To identify a variable number of tandem repeats (VNTR) typing method that is suitable for molecular epidemiological study of tuberculosis in China.Methods We systematically evaluated the commonly used VNTR typing methods,including 4 methods (MIRU-12,VNTR-15/VNTR-24 and VNTR "24 + 4") proposed by foreign colleagues and 2 methods (VNTR-L15 and VNTR"9 + 3 ") developed by domestic researchers using population-based collection of 891 clinical isolates from 5 provinces across the country.Results The order(from high to low) of discriminatory power for the 6 VNTR typing methods was VNTR"24 + 4",VNTR"9 + 3",VNTR-24,VNTR-15,VNTR-L15 and MIRU-12.The discriminatory power of VNTR"9 + 3" was comparable with VNTR"24 + 4" and higher than that of VNTR15/24.The concordance for defining clustered and unique genotypes between VNTR"9 + 3" and VNTR "24 +4"was 96.59％.Condusions Our results suggest that VNTR"9 + 3" is a suitable method for molecular typing of M.tuberculosis in China by considering its high discriminatory power,high consistency with VNTR"24 +4" and relative small number of VNTR locus.%目的 探讨不同可变数目串联重复序列(VNTR)组合鉴定MTB临床菌株分型的效果并在全国推广使用.方法 连续收集国内5个区县的891株MTB菌株样本,通过计算不同VNTR组合的分辨力指数(HGI),系统评估目前常用的VNTR分型组合,包括国外推荐的12个散在分布重复单位(MIRU)位点组合(MIRU-12)、15/24 VNTR位点组合(VNTR-15/VNTR-24)、24 VNTR位点加4个高变位点组合(VNTR“24+4”)以及国内吕冰等建立的15位点组合(VNTR-L15)和本课题组筛选的VNTR“9+3”组合.结果 分辨力由高至低依次为VNTR“24+4”(0.999 2)、VNTR“9+3”(0.998 9)、VNTR-24 (0.992 9)、VNTR-15 (0.988 4)、VNTR-L15 (0.970 9)、MIRU-12(0.924 8).VNTR“9+3”的分型能力不仅超过VNTR-15,且高于VNTR-24,与分辨力最高的VNTR“24 +4”组合分型结果一致的菌株数为822株,一致率达到96.6％ (822/851).结论 VNTR“9+3”的分辨力和分型结果均与VNTR“24+4”相当,且具有位点数少、工作量小,易于推广的优点.建议将VNTR“9+3”组合作为我国MTB基因型分型的推荐方案推广应用.