Division of Experimental Animal Diseases, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan
School of Veterinary Medicine, Rakuno-Gakuen University, Hokkaido, Japan.
Appl Environ Microbiol. 2018 Mar 19;84(7). doi: 10.1128/AEM.02491-17. Print 2018 Apr 1.
Parasites of the Asia lineage, which are closely related to in Europe and sp. strain MO1 in the United States, were recently reported in sika deer () in eastern Japan. To identify the tick vector(s) for this parasite, we conducted a field survey in Hokkaido, Japan, where the infection rate in sika deer is the highest in the country. A specific PCR system which detects and discriminates between lineages within and between those lineages and showed that (11/822), but not sympatric (0/595) or sp. (0/163) ticks, carried Asia lineage. Genomic DNA was archived from salivary glands of partially engorged females and three isolates of Asia lineage were newly described. The 18S rRNA gene sequence of the isolates formed the Asia lineage cluster with those previously described in sika deer isolates. One salivary gland also contained parasites of U.S. lineage, which were subsequently isolated in a hamster (strain Etb5) was also detected in one tick. The 18S rRNA sequence of Etb5 was 99.7% identical to that of (AY046575) and was phylogenetically positioned in a taxon composed of isolates from Europe, China, and Russia. The geographical distribution of is consistent with that of in sika deer in Japan. These results suggest that is a principal vector for in Japan and Eurasia, where is predominantly distributed. The Asia lineage of parasites closely related to in Europe and sp. MO1 in the United States was recently reported in in eastern Japan. In this study, specific PCR for the Asia lineage identified 11 positives in 822 host-seeking ticks, a principal vector for many tick-borne disease agents. Gene sequences of three isolates obtained from DNA in salivary glands of female ticks were identical to each other and to those in We also demonstrate the coinfection of Asia lineage with U.S. lineage in a tick salivary gland and, furthermore, isolated the latter in a hamster. These results suggest that is the principal vector for as well as for , and both parasites may be occasionally cotransmitted by This report will be important for public health, since infection may occur through transfusion.
亚洲谱系寄生虫与欧洲的 密切相关，与美国的 sp. MO1 株在美国也有关联，最近在日本东部的梅花鹿（）中被发现。为了确定这种寄生虫的蜱虫媒介（），我们在日本北海道进行了实地调查，那里的梅花鹿感染率是全国最高的。一种特定的 PCR 系统可以检测和区分 和谱系内以及这些谱系与 之间的差异，结果表明，只有（11/822）而不是同域的（0/595）或 sp.（0/163）蜱携带亚洲谱系。从部分饱食的雌性唾液腺中提取了基因组 DNA，并新描述了三个亚洲谱系分离株。分离株的 18S rRNA 基因序列与以前在梅花鹿分离株中描述的亚洲谱系聚类。一个唾液腺还含有美国谱系的寄生虫，随后在仓鼠（Etb5 株）中也分离出了这种寄生虫。Etb5 的 18S rRNA 序列与 （AY046575）的序列 99.7%相同，并且在由欧洲、中国和俄罗斯的 分离株组成的分类群中具有系统发育位置。的地理分布与日本梅花鹿中的分布一致。这些结果表明，在日本和欧亚大陆，是主要的寄生虫媒介，而在那里则广泛分布。最近在日本东部的梅花鹿中发现了与欧洲的 密切相关的亚洲谱系寄生虫以及美国的 sp. MO1。在这项研究中，针对亚洲谱系的特定 PCR 鉴定出 822 只宿主寻找蜱中 11 个阳性，这是许多蜱传疾病病原体的主要媒介。从雌性蜱虫唾液腺中的 DNA 获得的三个分离株的基因序列彼此相同，与我们还证明了在蜱虫的唾液腺中同时感染了亚洲谱系和美国谱系，并且在仓鼠中分离出了后者。这些结果表明，是许多蜱传疾病病原体的主要媒介，并且这两种寄生虫可能偶尔会通过 共同传播。该报告对于公共卫生非常重要，因为感染可能通过输血发生。
