Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK.
Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, AL9 7TA, UK.
Vet Parasitol. 2018 Oct 15;262:42-46. doi: 10.1016/j.vetpar.2018.09.008. Epub 2018 Sep 18.
Angiostrongylus vasorum is a nematode parasite of the pulmonary arteries and heart that infects domestic and wild canids. Dogs (Canis familiaris) and red foxes (Vulpes vulpes) are the most commonly affected definitive hosts. Recent studies suggest that angiostrongylosis is an emerging disease, and that red foxes may play an important role in the epidemiology of the parasite. Genetic analyses of parasites collected from dogs and foxes throughout Europe have shown that the same parasite haplotypes are commonly shared between different host species. However, the extent of genetic diversity within local A. vasorum populations and individual hosts is unknown. The objective of the present study was to assess the occurrence of genetic diversity among A. vasorum (a) recovered from different foxes within the Greater London area (a localised population, single worm per fox dataset); and (b) hosted within single foxes (multiple worms per fox dataset). During 2016, A. vasorum worms were collected from foxes culled for other purposes in London. DNA was extracted from each parasite and a partial fragment of the mitochondrial cytochrome oxidase subunit 1 (mtCOI) gene was amplified and sequenced. Sequences from the single worm dataset were compared with those published elsewhere. Combined, 19 haplotypes were described of which 15 were identified from foxes found in London, indicating that considerable genetic diversity can be detected within a local geographic area. Analysis of the multiple worm dataset identified 22 haplotypes defining worms recovered from just six foxes, emphasising the relevance of wild canines as reservoirs of genetic diversity. This is the first study to explore the genetic complexity of individual fox-hosted A. vasorum populations.
血管圆线虫是一种寄生在肺动脉和心脏的线虫寄生虫，感染了家养和野生犬科动物。犬（Canis familiaris）和赤狐（Vulpes vulpes）是最常受影响的终末宿主。最近的研究表明，血管圆线虫病是一种新兴疾病，赤狐可能在寄生虫的流行病学中发挥重要作用。对来自欧洲各地的犬和狐寄生虫的基因分析表明，相同的寄生虫单倍型在不同的宿主物种中经常共享。然而，尚不清楚当地血管圆线虫种群和单个宿主内的遗传多样性程度。本研究的目的是评估（a）从大伦敦地区不同狐狸中回收的血管圆线虫（每只狐狸一个寄生虫样本，数据集中每只狐狸只有一个寄生虫）和（b）单个狐狸中（每只狐狸多个寄生虫样本，数据集中每只狐狸有多个寄生虫）的遗传多样性。在 2016 年，从伦敦因其他目的而被扑杀的狐狸中收集了血管圆线虫蠕虫。从每个寄生虫中提取 DNA，并扩增和测序线粒体细胞色素氧化酶亚基 1（mtCOI）基因的部分片段。将单虫数据集的序列与其他地方发表的序列进行比较。共描述了 19 个单倍型，其中 15 个是从伦敦发现的狐狸中鉴定出来的，这表明在一个局部地理区域内可以检测到相当大的遗传多样性。对多虫数据集的分析确定了 22 个单倍型，这些单倍型定义了从仅 6 只狐狸中回收的蠕虫，这强调了野生动物作为遗传多样性的重要储存库。这是首次探索个体狐宿主血管圆线虫种群遗传复杂性的研究。
