Küchler Stefan Martin, Kehl Siegfried, Dettner Konrad
Department of Animal Ecology II, University of Bayreuth, Universitätsstrasse 30, Bayreuth, Germany.
FEMS Microbiol Ecol. 2009 May;68(2):201-11. doi: 10.1111/j.1574-6941.2009.00665.x.
In the present study, Rickettsia sp. was detected in four water beetles of the genus Deronectes (Dytiscidae) for the first time. Rickettsiae were found in 100% of examined specimens of Deronectes platynotus (45/45), 39.4% of Deronectes aubei (28/71), 40% of Deronectes delarouzei (2/5) and 33.3% of Deronectes semirufus (1/3). Analysis of 16S rRNA gene sequences revealed a phylogenetic relationship with rickettsial isolates of Limonia chorea (Diptera), tentatively classified as members of the basal ancestral group. Phylogenetic analysis of the gltA (citrate synthase) gene sequences showed that Deronectes symbionts were closest to bacterial symbionts from spiders. Ultrastructural examinations revealed typical morphological features and intracellular arrangements of rickettsiae. The distribution, transmission and localization of Rickettsia sp. in D. platynotus were studied using a diagnostic PCR assay and FISH. Eggs from infected females of D. platynotus were all Rickettsia-positive, indicative of a vertical transmission.
在本研究中，首次在4只龙虱属（龙虱科）水甲虫中检测到立克次氏体属细菌。在100%的扁龙虱（45/45）检测标本、39.4%的奥氏龙虱（28/71）、40%的德拉鲁龙虱（2/5）和33.3%的半红棕色龙虱（1/3）中发现了立克次氏体。对16S rRNA基因序列的分析揭示了与舞蹈家大蚊（双翅目）立克次氏体分离株的系统发育关系，暂定归类为基础祖先组的成员。对gltA（柠檬酸合酶）基因序列的系统发育分析表明，龙虱共生菌与蜘蛛的细菌共生菌关系最为密切。超微结构检查揭示了立克次氏体的典型形态特征和细胞内排列。利用诊断性PCR检测和荧光原位杂交技术研究了扁龙虱中立克次氏体属细菌的分布、传播和定位。扁龙虱感染雌虫所产的卵均为立克次氏体阳性，表明存在垂直传播。
