Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Science, Novosibirsk, Russia.
Omsk Research Institute of Natural Focal Infections, Omsk, Russia.
Ticks Tick Borne Dis. 2020 Jul;11(4):101440. doi: 10.1016/j.ttbdis.2020.101440. Epub 2020 Apr 9.
Wild animals are reservoir hosts for a number of tick-transmitted agents, and long-term persistence of the agents is a key factor for their effective transmission from animal hosts to ticks. To study the persistence of Anaplasmataceae in rodents, 59 adult Myodes spp. voles (M. rutilus, M. rufocanus, and M. glareolus) were captured in Omsk Province, Asian Russia, freed from all ectoparasites, and kept in individual cages. Their blood samples were regularly analyzed for the presence of DNA of Anaplasma phagocytophilum, Ehrlichia muris, and "Candidatus Neoehrlichia mikurensis". Anaplasma phagocytophilum, E. muris, and mixed infections were found in 29 (49 %), 17 (29 %), and 14 (24 %) voles, respectively. DNA of "Candidatus N. mikurensis" was not identified. Long-term persistence of A. phagocytophilum and E. muris in naturally infected Myodes spp. was shown for the first time. Thus, 12 animals with A. phagocytophilum were found infected for more than three months and four of them carried the bacterium throughout 22-55 weeks of observation. Four voles were infected with E. muris for 26-40 weeks. Fragments of groESL operon were sequenced for genotyping A. phagocytophilum and E. muris. In voles with A. phagocytophilum, the determined sequences belonged to two phylogenetic clusters. Most sequences were identical or closely related to those found in small mammals and Ixodes trianguliceps ticks from Western Siberia and European countries; one sequence was previously identified in rodents and Ixodes persulcatus and Ixodes pavlovskyi ticks from Asian Russia. Sequences of groESL fragments from E. muris were close to those determined previously in small mammals and I. persulcatus ticks from Siberia. In addition, a new groESL sequence of E. muris was identified in one vole and the sequence substantially differed from all known corresponding E. muris sequences (≥ 14 mismatches).
野生动物是许多蜱传病原体的储存宿主，病原体的长期存在是其从动物宿主有效传播到蜱的关键因素。为了研究 Anaplasmataceae 在啮齿动物中的持久性，从俄罗斯亚洲奥姆斯克省捕获了 59 只成年 Myodes spp. 田鼠（M. rutilus、M. rufocanus 和 M. glareolus），清除了所有外寄生虫，并将其饲养在单独的笼子中。定期分析它们的血液样本，以检测是否存在嗜吞噬细胞无形体、鼠埃立克体和“候选新立克次体”的 DNA。在 29 只（49%）、17 只（29%）和 14 只（24%）田鼠中分别发现了嗜吞噬细胞无形体、鼠埃立克体和混合感染。未鉴定出“候选新立克次体”的 DNA。首次证明了天然感染的 Myodes spp. 中嗜吞噬细胞无形体和鼠埃立克体的长期存在。因此，在 12 只感染嗜吞噬细胞无形体的动物中发现其感染超过三个月，其中 4 只在 22-55 周的观察期间携带该细菌。4 只田鼠感染鼠埃立克体长达 26-40 周。对 groESL 操纵子片段进行测序，以对嗜吞噬细胞无形体和鼠埃立克体进行基因分型。在感染嗜吞噬细胞无形体的田鼠中，确定的序列属于两个系统发育群。大多数序列与在西伯利亚和欧洲国家的小型哺乳动物和三突伊氏革蜱中发现的序列相同或密切相关；一个序列以前在俄罗斯亚洲的啮齿动物和三突伊氏革蜱中被发现。鼠埃立克体 groESL 片段的序列与以前在西伯利亚的小型哺乳动物和三突伊氏革蜱中确定的序列非常接近。此外，在一只田鼠中发现了鼠埃立克体的一个新 groESL 序列，该序列与所有已知的相应鼠埃立克体序列（≥ 14 个错配）明显不同。
