东非侵袭性牛蜱：在乌干达东南部发现 Rhipicephalus microplus 的形态学和分子确认。
Invasive cattle ticks in East Africa: morphological and molecular confirmation of the presence of Rhipicephalus microplus in south-eastern Uganda.
机构信息
College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, P.O. Box 7062, Kampala, Uganda.
ClinVet International (Pty) Ltd, P.O. Box 11186, Universitas, 9321, Bloemfontein, South Africa.
出版信息
Parasit Vectors. 2020 Apr 3;13(1):165. doi: 10.1186/s13071-020-04043-z.
BACKGROUND
Rhipicephalus microplus, an invasive tick species of Asian origin and the main vector of Babesia species, is considered one of the most widespread ectoparasites of livestock. The tick has spread from its native habitats on translocated livestock to large parts of the tropical world, where it has replaced some of the local populations of Rhipicephalus decoloratus ticks. Although the tick was reported in Uganda 70 years ago, it has not been found in any subsequent surveys. This study was carried out to update the national tick species distribution on livestock in Uganda as a basis for tick and tick-borne disease control, with particular reference to R. microplus.
METHODS
The study was carried out in Kadungulu, Serere district, south-eastern Uganda, which is dominated by small scale livestock producers. All the ticks collected from 240 cattle from six villages were identified microscopically. Five R. microplus specimens were further processed for phylogenetic analysis and species confirmation.
RESULTS
The predominant tick species found on cattle was Rhipicephalus appendiculatus (86.9 %; n = 16,509). Other species found were Amblyomma variegatum (7.2 %; n = 1377), Rhipicephalus evertsi (2.3 %; n = 434) and R. microplus (3.6 %; n = 687). Phylogenetic analysis of the 12S rRNA, 16S rRNA and ITS2 gene sequences of R. microplus confirmed the morphological identification.
CONCLUSIONS
It is concluded that R. microplus has replaced R. decoloratus in the sampled villages in Kadungulu sub-county, since the latter was not any longer found in this area. There is currently no livestock movement policy in force in Uganda, which could possibly limit the further spread of R. microplus ticks. Future surveys, but also retrospective surveys of museum specimens, will reveal the extent of distribution of R. microplus in Uganda and also for how long this tick has been present on livestock without being noticed.
背景
亚洲起源的侵袭性蜱种 Rhipicephalus microplus 是巴贝斯虫属的主要传播媒介，被认为是家畜最广泛的外寄生虫之一。这种蜱已从其原生栖息地（被转移的牲畜）传播到热带世界的大部分地区，在那里它取代了一些当地的 Rhipicephalus decoloratus 蜱种群。尽管这种蜱在 70 年前就已在乌干达被报道，但在随后的调查中并未发现。本研究旨在更新乌干达家畜的 tick 物种分布，作为 tick 和 tick 传播疾病控制的基础，特别是针对 R. microplus。
方法
该研究在乌干达东南部 Serere 区的 Kadungulu 进行，该地区以小型牲畜生产者为主。从六个村庄的 240 头牛中采集的所有蜱都进行了显微镜鉴定。进一步处理了 5 个 R. microplus 标本进行系统发育分析和物种确认。
结果
在牛身上发现的主要 tick 物种是 Rhipicephalus appendiculatus（86.9%；n=16509）。其他发现的物种包括 Amblyomma variegatum（7.2%；n=1377）、Rhipicephalus evertsi（2.3%；n=434）和 R. microplus（3.6%；n=687）。R. microplus 的 12S rRNA、16S rRNA 和 ITS2 基因序列的系统发育分析证实了形态学鉴定。
结论
结论是，R. microplus 已在 Kadungulu 分区的采样村庄中取代了 R. decoloratus，因为后者在该地区已不再存在。乌干达目前没有实施牲畜流动政策，这可能会限制 R. microplus 蜱的进一步传播。未来的调查，以及对博物馆标本的回顾性调查，将揭示 R. microplus 在乌干达的分布范围，以及这种 tick 在未被注意到的情况下在牲畜身上存在了多长时间。
Zotero 插件