van Soolingen D, Hoogenboezem T, de Haas P E, Hermans P W, Koedam M A, Teppema K S, Brennan P J, Besra G S, Portaels F, Top J, Schouls L M, van Embden J D
Diagnostic Laboratory for Infectious Diseases and Perinatal Screening, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
Int J Syst Bacteriol. 1997 Oct;47(4):1236-45. doi: 10.1099/00207713-47-4-1236.
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 from Mycobacterium tuberculosis in 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 the M. tuberculosis reference laboratory strain H37Rv and clinical isolates of M. tuberculosis and Mycobacterium bovis. Furthermore, the So93 isolate differed from all M. tuberculosis complex 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 of M. tuberculosis obtained 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 known M. tuberculosis complex taxa, M. tuberculosis, Mycobacterium africanum, M. bovis, and Mycobacterium 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 the M. tuberculosis complex and the newly described Canetti grouping should be regarded as a single species, which likely will be designated "M. tuberculosis".
为了鉴定从一名患有淋巴结炎的2岁索马里患者身上分离出的一株不寻常的分枝杆菌菌株，我们应用了各种以前未用于分枝杆菌分类的分子方法。这一分离株命名为So93，在生化测试及其16S rRNA序列方面与结核分枝杆菌没有差异，但产生光滑有光泽的菌落，这对该物种来说非常罕见。这种光滑表型不稳定，会以低频率不可逆地转变为粗糙菌落形态。这两种菌落类型对豚鼠的毒性相同，表现出典型的结核病症状。两种形态型的代时均短于结核分枝杆菌参考实验室菌株H37Rv以及结核分枝杆菌和牛分枝杆菌的临床分离株。此外，So93分离株与迄今为止描述的所有结核分枝杆菌复合群菌株不同，它只有一个插入序列IS1081拷贝、直接重复簇的组成异常，以及具有特征性的酚糖脂和脂寡糖。这种糖脂以前仅在1969年法国卡内蒂获得的一株光滑结核分枝杆菌分离株中观察到。对卡内蒂菌株的分析表明，它几乎具有So93所有的遗传特性，这将这两种菌株与已知的结核分枝杆菌复合群分类单元、结核分枝杆菌、非洲分枝杆菌、牛分枝杆菌和微小分枝杆菌区分开来。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。这项部分基于以前未使用的分子标准的研究支持了这样一种观点，即结核分枝杆菌复合群中的既定成员和新描述的卡内蒂类群应被视为一个单一物种，可能会被命名为“结核分枝杆菌”。
