Abstract:
Babesia spp. and Theileria spp. are tick-borne protozoan parasites with veterinary importance. In China, epidemiological and genetic investigations on many Babesia and Theileria species were still absent in many areas and many tick species. From Aug 2021 to May 2023, 645 ticks were collected from the body surface of domestic animals (camels, goats, sheep, and cattle) using tweezers in seven counties in three provinces including Xinjiang (Qitai, Mulei, Hutubi, and Shihezi counties), Chongqing (Youyang and Yunyang counties), and Qinghai (Huangzhong county). Three tick species were morphologically and molecularly identified (334 Hyalomma asiaticum from Xinjiang, 245 Rhipicephalus microplus from Chongqing, and 66 Haemaphysalis qinghaiensis from Qinghai). A total of three Babesia species and two Theileria species were detected targeting the 18S gene. The COI and cytb sequences were also recovered from Babesia strains for further identification. In R. microplus from Chongqing, Babesia bigemina, the agent of bovine babesiosis, was detected. Notably, in H. asiaticum ticks from Xinjiang, a putative novel genotype of Babesia caballi was identified (0.90%, 3/334), whose COI and cytb genes have as low as 85.82% and 90.64-90.91% nucleotide identities to currently available sequences. It is noteworthy whether the sequence differences of its cytb contribute to the drug resistance of this variant due to the involvement of cytb in the drug resistance of Babesia. In addition, Theileria orientalis and Theileria annulata were detected in R. microplus from Chongqing (12.20%, 31/245) and H. asiaticum from Xinjiang (1.50%, 5/334), respectively. These results suggest that these protozoan parasites may be circulating in domestic animals in these areas. The pathogenicity of the novel genotype of B. caballi also warrants further investigation.
摘要:
巴贝西亚。和Theileriaspp.是tick虫传播的原生动物寄生虫,具有兽医重要性。在中国,在许多地区和许多tick虫物种中,仍然没有对许多Babesia和Theileria物种进行流行病学和遗传调查。从2021年8月到2023年5月,从家畜的身体表面收集了645只蜱(骆驼,山羊,绵羊,和牛)在新疆(奇台,穆雷,呼图比,和石河子县),重庆(阜阳和云阳县),和青海(陇中县)。对三种蜱进行了形态学和分子鉴定(来自新疆的334个Hyalommaasiaticum,245来自重庆的微小根孢,和来自青海的66名青海红血丝)。总共检测到针对18S基因的三个巴贝虫物种和两个Theileria物种。还从巴贝虫菌株中回收COI和cytb序列用于进一步鉴定。在来自重庆的R.microplus,babesiabigemina,牛babesiosis的代理人,被检测到。值得注意的是,在来自新疆的H.siaticum蜱中,鉴定出一种推定的新基因型巴贝斯虫(0.90%,3/334),其COI和cytb基因与目前可用的序列具有低至85.82%和90.64-90.91%的核苷酸同一性。值得注意的是,由于cytb参与了巴贝虫的耐药性,因此其cytb的序列差异是否有助于该变体的耐药性。此外,在重庆的R.microplus中检测到东方Theileriaornulata(12.20%,31/245)和来自新疆的积雪草(1.50%,5/334),分别。这些结果表明,这些原生动物寄生虫可能在这些地区的家畜中循环。新基因型B.caballi的致病性也值得进一步研究。