Coxiella symbiont in the tick Ornithodoros rostratus (Acari: Argasidae)
Coxiella symbiont in the tick Ornithodoros rostratus (Acari: Argasidae)
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DOI：
10.1016/j.ttbdis.2012.02.003
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发表时间：
2012-01-01
影响因子：
3.2
通讯作者：
Labruna, Marcelo B.
中科院分区：
文献类型：
--
作者：
Almeida, Aliny P.;Marcili, Arlei;Labruna, Marcelo B.
在本研究中，通过分子检测确定了来自巴西潘塔纳尔地区的喙缘鸟蜱（成虫、若虫和卵）中是否存在与蜱相关的细菌和原生动物。在这些蜱中，没有检测到来自巴贝虫属和肝虫属的原生动物以及来自立克次体、疏螺旋体、无形体和埃利希体属的细菌的DNA。相反，所有测试的蜱 (100%) 均产生 3 个柯克斯体基因（16S rRNA、pyrG、cap）的 PCR 产物。对 3 个扩增基因（16S rRNA、pyrG、cap）进行的 PCR 和系统发育分析表明，感染 rostratus 蜱的病原体是柯克斯体属的成员。该生物体与其他软蜱物种（Argasidae）的柯克斯体共生体分组，并具有不同的 C. burnetii 分离株作为姐妹群，并且这两个群体形成一个进化枝，该进化枝与包含硬蜱物种（Ixodidae）的柯克斯体共生体的另一个进化枝分组。对蜱线粒体 16S rRNA 基因数据库的分析表明，蜱及其柯克斯体共生体具有系统发育一致性，该数据库主要由先前显示含有柯克斯体共生体的蜱物种组成。此外，这些结果表明蜱虫和柯克斯体共生体之间经历了很长一段时间的共同进化，并表明最初的感染可能发生在两个主要蜱科Argasidae（软蜱）和Ixodidae（硬蜱）的共同祖先中。然而，这种进化关系必须通过对其他蜱种和扩大的种群进行更广泛的测试来证实。 (c) 2012 年爱思唯尔有限公司。版权所有。
In the present study, the presence of tick-associated bacteria and protozoa in Ornithodoros rostratus ticks (adults, nymphs, and eggs) from the Pantanal region of Brazil were determined by molecular detection. In these ticks, DNA from protozoa in the genera Babesia and Hepatozoon, and bacteria from the genera Rickettsia, Borrelia, Anaplasma, and Ehrlichia were not detected. Conversely, all tested ticks (100%) yielded PCR products for 3 Coxiella genes (16S rRNA, pyrG, cap). PCR and phylogenetic analysis of 3 amplified genes (16S rRNA, pyrG, cap) demonstrated that the agent infecting O. rostratus ticks was a member of the genus Coxiella. This organism grouped with Coxiella symbionts of other soft tick species (Argasidae), having different isolates of C. burnetii as a sister group, and these 2 groups formed a clade that grouped with another clade containing Coxiella symbionts of hard tick species (Ixodidae). Analysis of tick mitochondrial 16S rRNA gene database composed mostly of tick species previously shown to harbor Coxiella symbionts suggests a phylogenetic congruence of ticks and their Coxiella symbionts. Furthermore, these results suggest a very long period of coevolution between ticks and Coxiella symbionts and indicates that the original infection may have occurred in an ancestor common to the 2 main tick families, Argasidae (soft ticks) and Ixodidae (hard ticks). However, this evolutionary relationship must be confirmed by more extensive testing of additional tick species and expanded populations. (c) 2012 Elsevier GmbH. All rights reserved.