Margos Gabriele, Gatewood Anne G, Aanensen David M, Hanincová Klára, Terekhova Darya, Vollmer Stephanie A, Cornet Muriel, Piesman Joseph, Donaghy Michael, Bormane Antra, Hurn Merrilee A, Feil Edward J, Fish Durland, Casjens Sherwood, Wormser Gary P, Schwartz Ira, Kurtenbach Klaus
Departments of Biology and Biochemistry and Mathematical Sciences, University of Bath, Bath BA2 7AY, United Kingdom.
Proc Natl Acad Sci U S A. 2008 Jun 24;105(25):8730-5. doi: 10.1073/pnas.0800323105. Epub 2008 Jun 23.
Lyme borreliosis, caused by the tick-borne bacterium Borrelia burgdorferi, has become the most common vector-borne disease in North America over the last three decades. To understand the dynamics of the epizootic spread and to predict the evolutionary trajectories of B. burgdorferi, accurate information on the population structure and the evolutionary relationships of the pathogen is crucial. We, therefore, developed a multilocus sequence typing (MLST) scheme for B. burgdorferi based on eight chromosomal housekeeping genes. We validated the MLST scheme on B. burgdorferi specimens from North America and Europe, comprising both cultured isolates and infected ticks. These data were compared with sequences for the commonly used genetic markers rrs-rrlA intergenic spacer (IGS) and the gene encoding the outer surface protein C (ospC). The study demonstrates that the concatenated sequences of the housekeeping genes of B. burgdorferi provide highly resolved phylogenetic signals and that the housekeeping genes evolve differently compared with the IGS locus and ospC. Using sequence data, the study reveals that North American and European populations of B. burgdorferi correspond to genetically distinct populations. Importantly, the MLST data suggest that B. burgdorferi originated in Europe rather than in North America as proposed previously.
莱姆病螺旋体病由蜱传播的伯氏疏螺旋体引起，在过去三十年里已成为北美最常见的媒介传播疾病。为了解这种动物流行病传播的动态并预测伯氏疏螺旋体的进化轨迹，关于该病原体种群结构和进化关系的准确信息至关重要。因此，我们基于八个染色体管家基因开发了一种用于伯氏疏螺旋体的多位点序列分型（MLST）方案。我们在来自北美和欧洲的伯氏疏螺旋体标本上验证了该MLST方案，这些标本包括培养的分离株和受感染的蜱。将这些数据与常用遗传标记核糖体RNA小亚基-核糖体RNA大亚基基因间间隔区（IGS）和编码外膜蛋白C（ospC）的基因的序列进行了比较。该研究表明，伯氏疏螺旋体管家基因的串联序列提供了高度解析的系统发育信号，并且与IGS位点和ospC相比，管家基因的进化方式不同。利用序列数据，该研究揭示北美和欧洲的伯氏疏螺旋体种群对应于基因上不同的种群。重要的是，MLST数据表明伯氏疏螺旋体起源于欧洲，而不是如先前所提出的起源于北美。
