Isolation of Rickettsia, Rickettsiella, and Spiroplasma from Questing Ticks in Japan Using Arthropod Cells
Isolation of Rickettsia, Rickettsiella, and Spiroplasma from Questing Ticks in Japan Using Arthropod Cells
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使用节肢动物细胞从日本探寻蜱中分离立克次体、立克次体和螺原体
DOI：
10.1089/vbz.2018.2373
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发表时间：
2019
影响因子：
2.1
通讯作者：
Nakao Ryo
中科院分区：
文献类型：
--
作者：
Thu May June;Qiu Yongjin;Kataoka-Nakamura Chikako;Sugimoto Chihiro;Katakura Ken;Isoda Norikazu;Nakao Ryo
蜱是吸血的体外寄生虫，可将人畜共患病原体传播给人类和动物。蜱类不仅携带病原微生物，还携带内共生菌。虽然已知一些蜱内共生体对蜱的生存至关重要，但它们在蜱中的作用仍然知之甚少。本研究的主要目的是利用来自肩突硬蜱胚胎（ISE 6）和白纹伊蚊幼虫（C6/36）的两个节肢动物细胞系从野外采集的蜱中分离和鉴定蜱传微生物。将源自日本收集的15种不同蜱种属的共计170份蜱匀浆接种至各细胞系中。通过PCR扩增真细菌的16 S核糖体DNA（rDNA）来证实细菌生长。在8周观察期内，分别使用ISE 6和C6/36细胞在14份和4份样本中确认了细菌分离。16 SrDNAPCR产物的序列分析表明，它们分别属于立克次体属、立克次体属和螺原体属，包括亚洲立克次体（2例）、瑞士立克次体（3例）、摩纳哥立克次体（2例）和田村立克次体（3例），以及一个未知基因型立克次体。LON（n= 2）。其中4个分离株与已鉴定的分离株相似性最高，分别是从北美蜱中分离的硬蜱螺原体和螺旋体。Bratislava 1与欧洲的蓖麻硬蜱分离株同源性为100%;在冰岛的格里姆西岛发现的。据我们所知，这是首次从蜱中成功分离立克次体的报道。本研究中获得的分离株可以进一步分析，以评估其在动物中的致病潜力及其作为蜱中共生体的作用。
Ticks are blood-sucking ectoparasites that transmit zoonotic pathogens to humans and animals. Ticks harbor not only pathogenic microorganisms but also endosymbionts. Although some tick endosymbionts are known to be essential for the survival of ticks, their roles in ticks remain poorly understood. The main aim of this study was to isolate and characterize tick-borne microorganisms from field-collected ticks using two arthropod cell lines derived fromIxodes scapularisembryos (ISE6) andAedes albopictuslarvae (C6/36). A total of 170 tick homogenates originating from 15 different tick species collected in Japan were inoculated into each cell line. Bacterial growth was confirmed by PCR amplification of 16S ribosomal DNA (rDNA) of eubacteria. During the 8-week observation period, bacterial isolation was confirmed in 14 and 4 samples using ISE6 and C6/36 cells, respectively. The sequencing analysis of the 16S rDNA PCR products indicated that they were previously known tick-borne pathogens/endosymbionts in three different genera:Rickettsia,Rickettsiella, andSpiroplasma.These included four previously validated rickettsial species namelyRickettsia asiatica(n= 2),Rickettsia helvetica(n= 3),Rickettsia monacensis(n= 2),andRickettsia tamurae(n= 3) and one uncharacterized genotypeRickettsiasp. LON (n= 2). Four isolates ofSpiroplasmahad the highest similarity with previously reportedSpiroplasmaisolates:Spiroplasma ixodetisobtained from ticks in North America andSpiroplasmasp. Bratislava 1 obtained fromIxodes ricinusin Europe, while two isolates ofRickettsiellashowed 100% identity withRickettsiellasp. detected fromIxodes uriaeat Grimsey Island in Iceland. To the best of our knowledge, this is the first report on successful isolation ofRickettsiellafrom ticks. The isolates obtained in this study can be further analyzed to evaluate their pathogenic potential in animals and their roles as symbionts in ticks.