The Foundation for Medical Research, 84-A, R.G. Thadani Marg, Worli, Bombay 400018, India.
Tuberculosis (Edinb). 2013 Mar;93(2):250-6. doi: 10.1016/j.tube.2012.10.004. Epub 2012 Dec 5.
We performed 12 loci MIRU-VNTR on 327 Mycobacterium tuberculosis (Mtb) isolates belonging to three major spoligotypes MANU1, CAS1_Delhi and Beijing from Mumbai, western India and two proximal rural locations. Complete allele and drug susceptibility data was available for 232 isolates. These included 143 MANU1 (ST100), 65 CAS1_Delhi (ST26) and 24 Beijing (ST1) isolates. Of the 232 isolates, 26 were rural consisting 6 CAS1_Delhi and 20 MANU1 isolates. Using eBURST multi-locus sequence typing (MLST), cluster analyses was performed for each of the spoligotypes and drug susceptibility profiles. MANU1 MLST consisted of 90 related isolates (clustered and grouped) and 53 singletons; CAS1_Delhi MLST consisted of 44 related isolates and 21 singletons; Beijing MLST consisted of 10 related isolates and 14 singletons. Although the number of related isolates were different in MANU1 (63%), CAS1_Delhi (68%) and Beijing (42%) clusters, it was not statistically significant. Furthermore, it was observed that while MANU1 and CAS1_Delhi singletons (n = 74) had only 12 (16%) MDR isolates, the Beijing MLST had 8/14 (57%) MDR singleton isolates. Phylogenetic ananlysis using minimum spanning tree (MST) and a UPGMA radial tree revealed MANU1 had the largest number of nodes as compared to the CAS1_Delhi and Beijing spoligotypes. Additionally the CAS isolates were more homogeneous than the MANU1 isolates. The 12 loci MIRU-VNTR was used to provide greater discrimination than spoligotyping, but 6 of the 12 loci provided less than 50% discriminatory power. The highest discrimination was achieved using locus 26 (80%). Our results concur with recent reports that the most discriminatory MIRU-VNTR combination varied across different lineages. The results also highlight the need for more robust genetic markers for studying the transmission of Mtb in endemic regions like India.
我们对来自印度西部孟买及其附近两个农村地区的 327 株结核分枝杆菌（Mtb）分离株进行了 12 个基因座的 MIRU-VNTR 分析，这些分离株属于三个主要的 spoligotype 类型：MANU1、CAS1_Delhi 和 Beijing。对于 232 株分离株，我们获得了完整的等位基因和药敏数据。这些分离株包括 143 株 MANU1（ST100）、65 株 CAS1_Delhi（ST26）和 24 株 Beijing（ST1）。在这 232 株分离株中，有 26 株来自农村，其中包括 6 株 CAS1_Delhi 和 20 株 MANU1 分离株。采用 eBURST 多位点序列分型（MLST）对每个 spoligotype 类型和药敏谱进行聚类分析。MANU1 MLST 由 90 个相关分离株（聚类和分组）和 53 个单倍型组成；CAS1_Delhi MLST 由 44 个相关分离株和 21 个单倍型组成；Beijing MLST 由 10 个相关分离株和 14 个单倍型组成。尽管 MANU1（63%）、CAS1_Delhi（68%）和 Beijing（42%）聚类中的相关分离株数量不同，但差异无统计学意义。此外，观察到 MANU1 和 CAS1_Delhi 单倍型（n=74）中只有 12 株（16%）为耐多药分离株，而 Beijing MLST 中有 8/14（57%）单倍型耐多药分离株。最小生成树（MST）和 UPGMA 径向树的系统发生分析表明，与 CAS1_Delhi 和 Beijing spoligotypes 相比，MANU1 具有最多的节点。此外，CAS 分离株比 MANU1 分离株更同质。12 个基因座的 MIRU-VNTR 比 spoligotyping 提供了更高的分辨率，但其中 6 个基因座的分辨率低于 50%。使用 26 个基因座（80%）获得了最高的分辨率。我们的结果与最近的报告一致，即最具分辨力的 MIRU-VNTR 组合因不同谱系而异。这些结果还强调需要更强大的遗传标记来研究印度等流行地区结核分枝杆菌的传播。
