Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom.
Infect Genet Evol. 2013 Mar;14:147-55. doi: 10.1016/j.meegid.2012.11.014. Epub 2012 Dec 5.
The Lyme borreliosis (LB) group of spirochaetes currently comprises 18 named species that vary in their geographic distribution, host specificity and ability to cause disease in humans. In Europe three species are most abundant, Borrelia afzelii, Borrelia garinii and Borrelia valaisiana but only two of these (B. garinii and B. afzelii) are regularly found in Asia as well. A recently published study has shown that Borrelia species associated with birds, such as B. garinii, showed limited geographic structuring between European countries while, the rodent associated species, B. afzelii, showed extensive spatial structuring in Europe. Here, we use multilocus sequence analysis to show that when the wider, inter-continental, distribution is considered, there is evidence of spatial structuring even in the bird-associated species B. garinii. Furthermore, our investigations into historical LB populations provided evidence for range expansions of B. garinii and B. afzelii populations in Europe in the distant past. We propose that the expansion of B. afzelii in Europe may be linked to rodent population expansions after the last glacial maximum.
莱姆病螺旋体（LB）组目前包括 18 个命名种，它们在地理分布、宿主特异性和引起人类疾病的能力上有所不同。在欧洲，三种物种最为丰富，即伯氏疏螺旋体、伽氏疏螺旋体和瓦氏疏螺旋体，但其中只有两种（B. garinii 和 B. afzelii）也在亚洲经常发现。最近的一项研究表明，与鸟类相关的伯氏疏螺旋体等物种在欧洲国家之间的地理结构有限，而与啮齿动物相关的物种 B. afzelii 在欧洲则表现出广泛的空间结构。在这里，我们使用多位点序列分析表明，当考虑更广泛的洲际分布时，即使在与鸟类相关的物种 B. garinii 中，也有空间结构的证据。此外，我们对历史上 LB 种群的调查为伯氏疏螺旋体和 B. afzelii 种群在欧洲的远古时期的扩张提供了证据。我们提出，B. afzelii 在欧洲的扩张可能与末次冰盛期后啮齿动物种群的扩张有关。
