背景:东南亚被认为是ixodid蜱多样性的热点。在这个地理区域,越南延伸到温带和热带气候区,因此有各种各样的蜱栖息地。然而,这个国家尚未报道过对ixodid蜱物种的分子系统发育研究。
方法:在本研究中,从牛身上收集了1788只ixodid蜱,越南北部三个省的10个地点的水牛和一只狗。滴答物种在形态上被鉴定出来,根据细胞色素c氧化酶亚基I(cox1)和16SrRNA基因对代表性标本进行分子分析。还根据该地区的典型寄主对越南本土的59种tick虫物种进行了审查。
结果:从牛和水牛中取出的大多数蜱被鉴定为Rhipicephalusmicroplus,包括所有的发展阶段。在1月至7月之间发现了幼虫和若虫,但直到12月才发现成虫。从牛中鉴定出的其他物种是Rhipicephaluslinnaei,血吸虫,完整的弱球和赤霉病。有趣的是,后三个物种仅由成年人代表,收集在一个省:儿子拉。7月,这只狗被若虫和R.linnaei的成虫感染。系统发育,来自越南的R.microplus属于这个物种的进化枝A,在中国,与以此名称识别的蜱虫分开聚集,台湾和巴基斯坦。来自越南的Amblyomma整合体属于Amblyommasp的单倍型系统发育组。缅甸报道。来自Shimog的H.cornigera的单独聚类获得了中等支持。
结论:三种蜱种(R.linnaei,A.integum和H.cornigera)在越南首次报道,因此,土著蜱物种的数量增加到62种。R.microplus的分化枝A和至少Rlinnaei来自Rhipicephalussanguineussensulato组。有多种系统发育证据表明,在南亚和东亚以R.haemphysaloides的名称报告的蜱中可能存在不同的物种。这是A.integrum在东南亚的第一份报告。
BACKGROUND: Southeast Asia is regarded as a hotspot for the diversity of ixodid ticks. In this geographical region, Vietnam extends through both temperate and tropical climate zones and therefore has a broad range of tick habitats. However, molecular-phylogenetic studies on ixodid tick species have not been reported from this country.
METHODS: In this study, 1788 ixodid ticks were collected from cattle, buffalos and a dog at 10 locations in three provinces of northern Vietnam. Tick species were identified morphologically, and representative specimens were molecularly analyzed based on the cytochrome c oxidase subunit I (cox1) and 16S rRNA genes. Fifty-nine tick species that are indigenous in Vietnam were also reviewed in the context of their typical hosts in the region.
RESULTS: Most ticks removed from cattle and buffalos were identified as Rhipicephalus microplus, including all developmental stages. Larvae and nymphs were found between January and July but adults until December. Further species identified from cattle were Rhipicephalus linnaei, Rhipicephalus haemaphysaloides, Amblyomma integrum and Haemaphysalis cornigera. Interestingly, the latter three species were represented only by adults, collected in one province: Son La. The dog was infested with nymphs and adults of R. linnaei in July. Phylogenetically, R. microplus from Vietnam belonged to clade A of this species, and R. haemaphysaloides clustered separately from ticks identified under this name in China, Taiwan and Pakistan. Amblyomma integrum from Vietnam belonged to the phylogenetic group of haplotypes of an Amblyomma sp. reported from Myanmar. The separate clustering of H. cornigera from Haemaphysalis shimoga received moderate support.
CONCLUSIONS: Three tick species (R. linnaei, A. integrum and H. cornigera) are reported here for the first time in Vietnam, thus increasing the number of indigenous tick species to 62. Clade A of R. microplus and at least R. linnaei from the group of Rhipicephalus sanguineus sensu lato occur in the country. There is multiple phylogenetic evidence that different species might exist among the ticks that are reported under the name R. haemaphysaloides in South and East Asia. This is the first report of A. integrum in Southeastern Asia.