Curry International Tuberculosis Center, Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, San Francisco, CA 94110, USA.
Int J Tuberc Lung Dis. 2013 Jul;17(7):885-91. doi: 10.5588/ijtld.12.0960.
Mycobacterium tuberculosis is classified into six phylogenetic lineages, each of which can be divided into sublineages. Sublineages of the same lineage have phenotypic differences, including their capacity to cause disease (pathogenicity).
We included TB cases caused by lineage 4 strains from our community-based study in San Francisco. Sublineage was determined by regions of difference. Genotypic clustering was determined by insertion sequence 6110 and polymorphic guanine-cytosine-rich sequence. Associations between sublineages and patient characteristics were evaluated with adjusted and unadjusted analyses.
The most frequent sublineage was H37Rv-like. In the adjusted analysis, sublineage 183 was associated with clustering and homelessness. We found that strains from different sublineages had convergent spoligotype and MIRU types.
Sublineage 183 is associated with genotypic clustering, evidence of its being more able to cause secondary cases than the other lineage 4 sublineages. This finding suggests that bacterial factors contribute to the pathogenesis of TB. Spoligotype and MIRU type cannot be used to infer sublineage.
结核分枝杆菌被分为六个系统发育谱系，每个谱系又可进一步分为亚谱系。同一谱系的亚谱系具有表型差异，包括致病能力（致病性）。
1）检验以下假设：引起美国大部分结核病（TB）的谱系 4 的不同亚谱系，通过基因型聚类（致病性的替代指标）确定其导致继发感染的能力存在差异；2）确定 spoligotype 和分枝杆菌间重复单位（MIRU）分型是否可以推断亚谱系。
我们纳入了来自旧金山社区研究中由谱系 4 菌株引起的 TB 病例。通过差异区域确定亚谱系。通过插入序列 6110 和多态性鸟嘌呤-胞嘧啶丰富序列确定基因型聚类。通过调整和未调整分析评估亚谱系与患者特征之间的关联。
最常见的亚谱系是 H37Rv 样。在调整分析中，亚谱系 183 与聚类和无家可归有关。我们发现来自不同亚谱系的菌株具有趋同 spoligotype 和 MIRU 类型。
亚谱系 183 与基因型聚类相关，表明其比其他谱系 4 亚谱系更有能力引起继发感染。这一发现表明细菌因素有助于结核病的发病机制。 spoligotype 和 MIRU 类型不能用于推断亚谱系。
