Yabuki M, Nakao M, Fukunaga M
Laboratory of Molecular Microbiology, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Hiroshima, Japan.
Microbiol Immunol. 1999;43(12):1097-102. doi: 10.1111/j.1348-0421.1999.tb03366.x.
Unfed adult Ixodes persulcatus ticks were collected from four locations of Nagano and Hokkaido in Japan. Infected Borrelia garinii were investigated by PCR-RFLP of the ospA and ospB gene sequences. The primer set amplified an approximately 1.6-kb DNA fragment (0.7-kb in some strains), and BsrI, BstYI, or NlaIII digestion of the product resulted in six distinctively different PCR-RFLP groups and two independent borrelial strains. The representatives in each PCR-RFLP group and individuals from the borrelial strains were sequenced, and their deduced amino acid sequences were aligned. A neighbor-joining phylogenetic analysis showed that the B. garinii OspA or OspB sequences were each divided into three major clusters including isolates from both the Nagano and Hokkaido locations. There was no local difference in OspA/B sequences between Nagano and Hokkaido. The osp gene of Borrelia burgdorferi sensu lato is highly heterogeneous, and this was also confirmed by our sequence analysis. Some strains of the different PCR-RFLP groups had closely related OspA sequences, while the OspB sequences of these strains were quite different. These findings suggested intraspecies gene exchange and recombination events between the two genes in B. garinii.
未进食的成年全沟硬蜱采自日本长野和北海道的四个地点。通过对ospA和ospB基因序列进行PCR-RFLP分析来研究感染的伯氏疏螺旋体。引物组扩增出一个约1.6kb的DNA片段（某些菌株中为0.7kb），对产物进行BsrI、BstYI或NlaIII酶切，产生六个明显不同的PCR-RFLP组和两个独立的疏螺旋体菌株。对每个PCR-RFLP组的代表菌株以及疏螺旋体菌株的个体进行测序，并对推导的氨基酸序列进行比对。邻接法系统发育分析表明，伯氏疏螺旋体OspA或OspB序列各自分为三个主要簇，包括来自长野和北海道地点的分离株。长野和北海道之间的OspA/B序列没有局部差异。伯氏疏螺旋体狭义种的osp基因高度异质，我们的序列分析也证实了这一点。不同PCR-RFLP组的一些菌株具有密切相关的OspA序列，而这些菌株的OspB序列则有很大差异。这些发现表明伯氏疏螺旋体中两个基因之间存在种内基因交换和重组事件。
