Department of Entomology, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel.
Appl Environ Microbiol. 2013 Jul;79(14):4246-52. doi: 10.1128/AEM.00721-13. Epub 2013 May 3.
Bacteria in the genus Rickettsiella (Coxiellaceae), which are mainly known as arthropod pathogens, are emerging as excellent models to study transitions between mutualism and pathogenicity. The current report characterizes a novel Rickettsiella found in the leafhopper Orosius albicinctus (Hemiptera: Cicadellidae), a major vector of phytoplasma diseases in Europe and Asia. Denaturing gradient gel electrophoresis (DGGE) and pyrosequencing were used to survey the main symbionts of O. albicinctus, revealing the obligate symbionts Sulcia and Nasuia, and the facultative symbionts Arsenophonus and Wolbachia, in addition to Rickettsiella. The leafhopper Rickettsiella is allied with bacteria found in ticks. Screening O. albicinctus from the field showed that Rickettsiella is highly prevalent, with over 60% of individuals infected. A stable Rickettsiella infection was maintained in a leafhopper laboratory colony for at least 10 generations, and fluorescence microscopy localized bacteria to accessory glands of the female reproductive tract, suggesting that the bacterium is vertically transmitted. Future studies will be needed to examine how Rickettsiella affects host fitess and its ability to vector phytopathogens.
里克特氏菌属（柯克斯体科）中的细菌主要作为节肢动物病原体而被人们所熟知，目前它们正作为研究共生关系和致病性之间转变的优秀模型而兴起。本报告介绍了一种在叶蝉 Orosius albicinctus（半翅目：叶蝉科）中发现的新型里克特氏菌，O. albicinctus 是欧洲和亚洲植原体病的主要载体。变性梯度凝胶电泳（DGGE）和焦磷酸测序用于调查 O. albicinctus 的主要共生体，除了里克特氏菌外，还揭示了专性共生体 Sulcia 和 Nasuia，以及兼性共生体 Arsenophonus 和 Wolbachia。叶蝉里克特氏菌与在蜱虫中发现的细菌有关。从野外筛选 O. albicinctus 表明，里克特氏菌的感染率非常高，超过 60%的个体受到感染。在叶蝉实验室群体中至少维持了 10 代稳定的里克特氏菌感染，荧光显微镜将细菌定位到雌性生殖道的附属腺，表明该细菌是垂直传播的。未来的研究将需要检查里克特氏菌如何影响宿主适应性及其作为植物病原体载体的能力。
