National Microbiology Laboratory, 1015 Arlington Avenue, Winnipeg, Manitoba R3E 3R2, Canada.
Tuberculosis (Edinb). 2010 Jan;90(1):31-8. doi: 10.1016/j.tube.2009.12.003. Epub 2010 Jan 6.
The current gold standard for Mycobacterium tuberculosis complex (MTBC) genotyping is insertion sequence (IS) 6110 restriction fragment length polymorphism (RFLP) as it provides the highest discriminatory power of all available MTBC genotyping methods. However, RFLP is labour intensive and the interpretation of data from this method can be susceptible to errors. In 2001 a rapid, reproducible variable number of tandem repeat (VNTR) based typing method using 12 mycobacterial interspersed repetitive units (MIRU) was developed. Despite this advancement, this method lacked the discriminatory power of IS6110-RFLP. More recently a set of 24 MIRU-VNTR loci was reported to have greater discriminatory power than the original 12 locus system and may exceed that of RFLP when combined with spoligotyping. We compared the 24 locus method to the 12 locus method in order to improve surveillance of tuberculosis in Canada. A random sample of 650 MTBC isolates from British Columbia, Saskatchewan, Manitoba and Quebec Canada was genotyped using the 24 MIRU loci. Comparison of the data for the 12 and 24 MIRU loci showed an increase of the Hunter-Gaston discriminatory index (HGDI) from 0.895 (12 loci) to 0.920 (24 loci). The implementation of the 24 locus MIRU-VNTR methods offers improvement in discriminatory power over the traditional 12 locus method. For long-term surveillance of MTBC within Canada, the use of 24 MIRU-VNTR loci will provide rapid, highly discriminatory molecular epidemiology information.
目前，分枝杆菌复合群（MTBC）基因分型的金标准是插入序列（IS）6110 限制片段长度多态性（RFLP），因为它提供了所有可用的 MTBC 基因分型方法中最高的区分能力。然而，RFLP 劳动强度大，并且该方法的数据解释可能容易出错。2001 年，开发了一种快速、可重复的基于可变数串联重复（VNTR）的分枝杆菌插入序列重复单位（MIRU）分型方法，该方法使用 12 个分枝杆菌插入序列重复单位（MIRU）。尽管有了这一进步，但这种方法缺乏 IS6110-RFLP 的区分能力。最近，报道了一套由 24 个 MIRU-VNTR 位点组成的系统，其区分能力大于原始的 12 个位点系统，并且当与 spoligotyping 结合使用时，其区分能力可能超过 RFLP。我们比较了 24 个位点方法和 12 个位点方法，以改善加拿大的结核病监测。对来自加拿大不列颠哥伦比亚省、萨斯喀彻温省、马尼托巴省和魁北克省的 650 株 MTBC 分离株进行了 24 个 MIRU 位点的随机抽样，使用 24 个 MIRU 位点对数据进行了比较。比较 12 个和 24 个 MIRU 位点的数据显示，Hunter-Gaston 区分指数（HGDI）从 0.895（12 个位点）增加到 0.920（24 个位点）。24 个 MIRU-VNTR 方法的实施提高了传统 12 个位点方法的区分能力。对于加拿大境内 MTBC 的长期监测，使用 24 个 MIRU-VNTR 位点将提供快速、高度区分的分子流行病学信息。
