A novel pathogenic taxon of the Mycobacterium tuberculosis complex, Canetti: Characterization of an exceptional isolate from Africa
A novel pathogenic taxon of the Mycobacterium tuberculosis complex, Canetti: Characterization of an exceptional isolate from Africa
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DOI：
10.1099/00207713-47-4-1236
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发表时间：
1997-10-01
期刊：
影响因子：
--
通讯作者：
vanEmbden，JDA
中科院分区：
文献类型：
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作者：
vanSoolingen，D;Hoogenboezem，T;vanEmbden，JDA
在试图表征一个不寻常的分枝杆菌菌株分离自2岁的索马里患者淋巴结炎，我们采用了各种分子方法，以前没有用于分枝杆菌的分类学分类。该分离株命名为So93，在生化试验和16S rRNA序列中与结核分枝杆菌没有区别，但产生光滑和有光泽的菌落，这是该物种的高度例外。这种光滑的表型是不稳定的，并且以低频率不可逆地转换为粗糙的菌落形态。两种菌落类型对豚鼠的毒性相同，表现出典型的结核病。两种形态型的世代时间都比M短。结核参考实验室菌株H37Rv和M.结核病和牛分枝杆菌。此外，So93分离物不同于所有M。迄今为止描述的结核病复合菌菌株仅具有插入序列IS 1081的单拷贝、同向重复簇的不寻常组成以及特征性酚糖脂和脂寡糖。这种糖脂以前只在M的光滑分离物中观察到。1969年由法国的Canetti发现。对Canetti菌株的分析表明，它几乎具有So93的所有遗传特性，将这两种菌株与已知菌株区分开来。tuberculosiscomplex taxa，M.结核分枝杆菌、非洲分枝杆菌、M.牛分枝杆菌和田鼠分枝杆菌。本文所述细菌群的天然宿主、宿主范围和传播方式目前尚不清楚。这项研究，部分是基于以前没有使用的分子标准，支持的想法，建立成员内的M。tuberculosiscomplex和新描述的Canetti分组应被视为一个单一的物种，可能将被命名为“M.肺结核”。
In an attempt to characterize an unusual mycobacterial strain isolated from a 2-year-old Somali patient with lymphadenitis, we applied various molecular methods not previously used for the taxonomic classification of mycobacteria. This isolate, designated So93, did not differ fromMycobacterium tuberculosisin the biochemical tests and in its 16S rRNA sequence, but produced smooth and glossy colonies, which is highly exceptional for this species. This smooth phenotype was unstable and switched nonreversibly to a rough colony morphology with a low frequency. The two colony types were equally virulent for the guinea pig, exhibiting characteristic tuberculous disease. Both morphotypes had shorter generation times than theM. tuberculosisreference laboratory strain H37Rv and clinical isolates ofM. tuberculosisandMycobacterium bovis. Furthermore, the So93 isolate differed from allM. tuberculosiscomplex strains described thus far by having only a single copy of insertion sequence IS1081, an unusual composition of the direct repeat cluster, and a characteristic phenolic glycolipid and lipooligosaccharide. This glycolipid had previously been observed only in a smooth isolate ofM. tuberculosisobtained in 1969 by Canetti in France. Analysis of the Canetti strain showed that it shared virtually all genetic properties characteristic of So93, distinguishing these two strains from the knownM. tuberculosiscomplex taxa,M. tuberculosis, Mycobacterium africanum, M. bovis, andMycobacterium microti. The natural reservoir, host range, and mode of transmission of the group of bacteria described in this paper are presently unknown. This study, partly based on not previously used molecular criteria, supports the idea that the established members within theM. tuberculosiscomplex and the newly described Canetti grouping should be regarded as a single species, which likely will be designated “M. tuberculosis”.