Chun J, Goodfellow M
Department of Microbiology, Medical School, Newcastle upon Tyne, United Kingdom.
Int J Syst Bacteriol. 1995 Apr;45(2):240-5. doi: 10.1099/00207713-45-2-240.
Partial sequences of the 16S rRNA genes of the type strains of nine species of the genus Nocardia were determined following the isolation and cloning of the amplified genes. These sequences were aligned with the sequences of representatives of the genera Corynebacterium, Gordona, Mycobacterium, Rhodococcus, and Tsukamurella, and phylogenetic trees were inferred by using the Fitch-Margoliash and neighbor-joining methods. The genus Nocardia formed a distinct clade that was most closely associated with the genus Rhodococcus. The average level of sequence similarity found among the type strains of the Nocardia species was 97.2 +/- 0.7%. Two sublines were recognized within the Nocardia clade; one encompassed Nocardia asteroides and related species, and the other encompassed Nocardia otitidiscaviarum and allied taxa. Separation of the two sublines is based on differences in helix 37-1. The results of isoprenoid quinone analyses provided evidence that nocardiae can be distinguished from all other actinomycete taxa on the basis of their characteristic menaquinone profiles. Nocardiae typically contain hexahydrogenated menaquinones with eight isoprene units in which the two end units are cyclized.
在对扩增基因进行分离和克隆后，测定了诺卡氏菌属9个种模式菌株的16S rRNA基因部分序列。将这些序列与棒状杆菌属、戈登氏菌属、分枝杆菌属、红球菌属和冢村氏菌属代表菌株的序列进行比对，并采用Fitch-Margoliash法和邻接法构建系统发育树。诺卡氏菌属形成了一个独特的分支，与红球菌属关系最为密切。诺卡氏菌属各菌种模式菌株之间的平均序列相似性水平为97.2±0.7%。在诺卡氏菌分支内可识别出两个亚系；一个包括星形诺卡氏菌及相关菌种，另一个包括耳炎诺卡氏菌及相关分类单元。两个亚系的分离基于螺旋37-1的差异。类异戊二烯醌分析结果表明，诺卡氏菌可根据其特征性的甲基萘醌谱与所有其他放线菌分类单元区分开来。诺卡氏菌通常含有具有八个异戊二烯单元的六氢化甲基萘醌，其中两个末端单元是环化的。
