USC INRA Bipar, Bartonella et Tiques, Maisons-Alfort, France.
PLoS One. 2013 Jul 24;8(7):e68956. doi: 10.1371/journal.pone.0068956. Print 2013.
Host-specificity is an intrinsic feature of many bacterial pathogens, resulting from a long history of co-adaptation between bacteria and their hosts. Alpha-proteobacteria belonging to the genus Bartonella infect the erythrocytes of a wide range of mammal orders, including rodents. In this study, we performed genetic analysis of Bartonella colonizing a rodent community dominated by bank voles (Myodes glareolus) and wood mice (Apodemus sylvaticus) in a French suburban forest to evaluate their diversity, their capacity to recombine and their level of host specificity. Following the analysis of 550 rodents, we detected 63 distinct genotypes related to B. taylorii, B. grahamii, B. doshiae and a new B. rochalimae-like species. Investigating the most highly represented species, we showed that B. taylorii strain diversity was markedly higher than that of B. grahamii, suggesting a possible severe bottleneck for the latter species. The majority of recovered genotypes presented a strong association with either bank voles or wood mice, with the exception of three B. taylorii genotypes which had a broader host range. Despite the physical barriers created by host specificity, we observed lateral gene transfer between Bartonella genotypes associated with wood mice and Bartonella adapted to bank voles, suggesting that those genotypes might co-habit during their life cycle.
宿主特异性是许多细菌病原体的固有特征，这是细菌与其宿主之间长期共同适应的结果。α-变形菌属的巴尔通体属感染范围广泛的哺乳动物目红细胞，包括啮齿动物。在这项研究中，我们对法国郊区森林中一个以林姬鼠（Myodes glareolus）和黑线姬鼠（Apodemus sylvaticus）为主的啮齿动物群落中定植的巴尔通体进行了遗传分析，以评估其多样性、重组能力和宿主特异性水平。在分析了 550 只啮齿动物后，我们检测到了 63 种与 B. taylorii、B. grahamii、B. doshiae 和一种新的类似 B. rochalimae 的物种相关的独特基因型。调查最具代表性的物种时，我们发现 B. taylorii 菌株多样性明显高于 B. grahamii，表明后者可能经历了严重的瓶颈效应。大多数回收的基因型与林姬鼠或黑线姬鼠强烈相关，除了三种具有更广泛宿主范围的 B. taylorii 基因型。尽管宿主特异性造成了物理屏障，但我们观察到与黑线姬鼠相关的巴尔通体基因型和适应林姬鼠的巴尔通体之间存在水平基因转移，表明这些基因型可能在其生命周期中共存。
