Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, United States of America.
Department of Biological Sciences, Old Dominion University, Norfolk, VA, United States of America.
PLoS One. 2022 Dec 6;17(12):e0278582. doi: 10.1371/journal.pone.0278582. eCollection 2022.
Bacterial endosymbionts are abundantly found in both hard and soft ticks. Occidentia massiliensis, a rickettsial endosymbiont, was first identified in the soft tick Ornithodoros sonrai collected from Senegal and later was identified in a hard tick Africaniella transversale. In this study, we noted the presence of Occidentia species, designated as Occidentia-like species, in a soft tick O. turicata americanus. Sequencing and phylogenetic analyses of the two genetic markers, 16S rRNA and groEL confirmed the presence of Occidentia-like species in O. turicata americanus ticks. The Occidentia-like species was noted to be present in all developmental stages of O. turicata americanus and in different tick tissues including ovaries, synganglion, guts and salivary gland. The levels of Occidentia-like species 16S rRNA transcripts were noted to be significantly higher in ovaries than in a gut tissue. In addition, Occidentia-like species groEL expression was noted to be significantly higher in tick synganglion than in ovaries and gut tissues. Furthermore, levels of Occidentia-like species 16S rRNA transcripts increased significantly upon O. turicata americanus blood feeding. Taken together, our study not only shows that Occidentia-like species is present in O. turicata americanus but also suggests that this bacterium may play a role in tick-bacteria interactions.
细菌内共生体在硬蜱和软蜱中都大量存在。奥西登西亚菌（Occidentia massiliensis）是一种立克次氏体内共生体，最初在塞内加尔采集的软蜱 Ornithodoros sonrai 中被鉴定出来，后来在硬蜱 Africaniella transversale 中也被鉴定出来。在这项研究中，我们注意到在软蜱 O. turicata americanus 中存在奥西登西亚菌（Occidentia massiliensis），被指定为类似奥西登西亚菌的物种。对两个遗传标记，16S rRNA 和 groEL 的测序和系统发育分析证实了 O. turicata americanus 蜱中存在类似奥西登西亚菌的物种。类似奥西登西亚菌的物种存在于 O. turicata americanus 的所有发育阶段以及不同的蜱组织中，包括卵巢、神经节、肠道和唾液腺。类似奥西登西亚菌的 16S rRNA 转录本水平在卵巢中明显高于肠道组织。此外，类似奥西登西亚菌的 groEL 表达在蜱神经节中明显高于卵巢和肠道组织。此外，类似奥西登西亚菌的 16S rRNA 转录本水平在 O. turicata americanus 吸血后显著增加。总之，我们的研究不仅表明类似奥西登西亚菌的物种存在于 O. turicata americanus 中，还表明这种细菌可能在蜱菌相互作用中发挥作用。
