Swanson Katherine I, Norris Douglas E
The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
Vector Borne Zoonotic Dis. 2008 Jun;8(3):397-405. doi: 10.1089/vbz.2007.0222.
White-footed mice (Peromyscus leucopus) serve as the principal reservoir for Borrelia burgdorferi and have been shown to remain infected for life. Complex infections with multiple genetic variants of B. burgdorferi occur in mice through multiple exposures to infected ticks or through exposure to ticks infected with multiple variants of B. burgdorferi. Using a combination of cloning and single strand conformation polymorphism (SSCP), B. burgdorferi ospC variation was assessed in serial samples collected from individual P. leucopus during a single transmission season. In individuals with ospC variation, at least seven ospC variants were recognized at each time point. One to four of these variants predominated at each time point; however, the predominant variants seldom remained consistent in an individual mouse throughout the entire sampling period. These results confirmed that mice in southern Maryland were persistently infected with multiple variants of B. burgdorferi throughout the transmission season. However, the presence of multiple ospC variants and the fluctuations in the frequency of these variants indicates that either new ospC variants are regularly introduced to this mouse population and predominate while the existing infections are cleared, or that the variation detected in the genetic profile at different time points reflects a complex mixture of B. burgdorferi populations whose relative frequencies may continually change.
白足鼠（白足鼠属）是伯氏疏螺旋体的主要宿主，并且已被证明会终身感染。白足鼠通过多次接触受感染的蜱虫或接触感染了多种伯氏疏螺旋体变体的蜱虫，从而发生多种伯氏疏螺旋体基因变体的复合感染。利用克隆和单链构象多态性（SSCP）相结合的方法，在单个传播季节从个体白足鼠采集的系列样本中评估了伯氏疏螺旋体ospC变异情况。在具有ospC变异的个体中，每个时间点至少识别出7种ospC变体。其中1至4种变体在每个时间点占主导地位；然而，在整个采样期间，单个小鼠中占主导地位的变体很少保持一致。这些结果证实，马里兰州南部的小鼠在整个传播季节持续感染多种伯氏疏螺旋体变体。然而，多种ospC变体的存在以及这些变体频率的波动表明，要么新的ospC变体定期引入该小鼠群体并在现有感染被清除时占主导地位，要么在不同时间点检测到的基因谱变异反映了伯氏疏螺旋体群体的复杂混合，其相对频率可能不断变化。
