Knox C L, Giffard P, Timms P
Centre for Molecular Biotechnology, School of Life Sciences, Queensland University of Technology, Brisbane, Australia.
Int J Syst Bacteriol. 1998 Oct;48 Pt 4:1323-31. doi: 10.1099/00207713-48-4-1323.
Sequencing of mba gene fragments of reference strains of Ureaplasma urealyticum serovars 1, 3, 6, 14 and 8, in addition to 33 clinical U. urealyticum isolates is reported. A phylogenetic tree deduced from alignment of these sequences clearly demonstrates two major clusters (confidence limit 100%), which equate to the parvo and T960 biovars, and five types, which have been designated mba 1, 3, 6, 8 and X. These relationships are supported by bootstrap analysis. Polymorphisms within the mba fragment of types mba 1, 3 and 6 were used to define nine subtypes (mba 1a, 1b, 3a, 3b, 3c, 3d, 3e, 6a and 6b), thus facilitating high resolution typing of U. urealyticum. Inclusion of reference strains for serovars 1, 3, 6 and 8 in the mba typing scheme showed that the results of this analysis are broadly consistent with currently accepted serotyping. In addition, a ure gene fragment from nine of the clinical isolates was amplified and sequenced. Comparisons of the sequences clearly distinguished the two biovars of U. urealyticum; however, this fragment was invariant within the parvo biovar. This study has shown that the mba sequence can reveal the fine details of the relationships between U. urealyticum isolates and also supports the significant evolutionary gap between the two biovars.
本文报道了解脲脲原体血清型1、3、6、14和8参考菌株以及33株临床解脲脲原体分离株的mba基因片段测序结果。根据这些序列比对推导的系统发育树清楚地显示出两个主要聚类（置信限度100%），分别对应细小生物变种和T960生物变种，以及五种类型，已命名为mba 1、3、6、8和X。这些关系得到了自展分析的支持。利用mba 1、3和6型mba片段内的多态性定义了九个亚型（mba 1a、1b、3a、3b、3c、3d、3e、6a和6b），从而便于对解脲脲原体进行高分辨率分型。在mba分型方案中纳入血清型1、3、6和8的参考菌株表明，该分析结果与目前公认的血清分型大致一致。此外，对九株临床分离株的ure基因片段进行了扩增和测序。序列比较清楚地区分了解脲脲原体的两个生物变种；然而，该片段在细小生物变种内是不变的。本研究表明，mba序列可以揭示解脲脲原体分离株之间关系的细微细节，也支持了两个生物变种之间显著的进化差距。
