Purpose

Coxiella burnetii is known for its potential as veterinary and human bacterial pathogen. The bacteria have been described in ticks, but their role in transmission of Q fever in humans is considered low. Coxiella endosymbionts closely related to C. burnetii have been also isolated from an extensive range of tick species and evidence is growing that these endosymbionts could be linked to human bacteremia. The aim of this study was to get new information on the presence of Coxiella species in ticks infesting wild and domestic hosts in Sardinia, Italy.

Methods

Here, 138 ticks collected from the study area were analyzed for the presence of C. burnetii and Coxiella-like bacteria by polymerase chain reaction (PCR), sequencing and philogenetic analyses using a set of primers targeting the 16S rRNA gene.

Results

DNA of Coxiella species was detected in 69% of the total ticks examined. Based on phylogenetic analysis, the 16S rRNA Coxiella genotypes identified in this study grouped in strongly supported monophyletic clades with identified reference sequences of CLEs detected from Rhipicephalus, Dermacentor, Haemaphysalis and Ornithodoros species and with Coxiella burnetii strains isolated worldwide.

Conclusion

This study reports the molecular detection of a high diversity of Coxiella-like bacteria in Sardinian ticks and confirms also the presence of C. burnetii in tick species previously identified in the island. The role that Coxiella-like endosymbionts play in Sardinian ticks and in their vertebrate hosts needs to be explored further.

中文翻译：

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来自意大利撒丁岛的人类、家养和野生宿主蜱中的 Coxiellaceae：类 Coxiella 内共生体的高度多样性

目的

Coxiella burnetii以其作为兽医和人类细菌病原体的潜力而闻名。已经在蜱中描述了这种细菌，但它们在人类 Q 热传播中的作用被认为很低。贝氏密切相关的共生贝氏柯克斯体已经从粗放蜱物种的范围也被分离和证据越来越多，这些共生细菌可能与人类菌血症。这项研究的目的是获得关于在意大利撒丁岛感染野生和家养宿主的蜱中存在Coxiella物种的新信息。

方法

在这里，使用一组针对 16S rRNA 基因的引物，通过聚合酶链反应 (PCR)、测序和系统发育分析，分析了从研究区域收集的 138 只蜱中是否存在C.burnetii和Coxiella样细菌。

结果

在 69% 的被检查的蜱中检测到了Coxiella物种的DNA 。基于系统发育分析，本研究中鉴定的 16S rRNA Coxiella基因型被归入强烈支持的单系进化枝中，其中 CLE 的参考序列从Rhipicephalus、Dermacentor、Haemaphysalis和Ornithodoros物种以及世界范围内分离的Coxiella burnetii菌株中检测到。

结论

这项研究报告了在撒丁岛蜱中高度多样性的类Coxiella细菌的分子检测，并证实了先前在该岛发现的蜱种中存在C.burnetii。该角色贝氏般的内共生菌在撒丁岛蜱，并在其脊椎动物宿主需求方面发挥有待进一步探讨。