Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.
Wildlife Veterinary Unit, Department of National Parks and Wildlife, Chilanga, Zambia.
Parasit Vectors. 2020 Nov 30;13(1):599. doi: 10.1186/s13071-020-04475-7.
Piroplasms are vector-borne intracellular hemoprotozoan parasites that infect wildlife and livestock. Wildlife species are reservoir hosts to a diversity of piroplasms and play an important role in the circulation, maintenance and evolution of these parasites. The potential for likely spillover of both pathogenic and non-pathogenic piroplasm parasites from wildlife to livestock is underlined when a common ecological niche is shared in the presence of a competent vector.
To investigate piroplasm diversity in wildlife and the cattle population of the greater Kafue ecosystem, we utilized PCR to amplify the 18S rRNA V4 hyper-variable region and meta-barcoding strategy using the Illumina MiSeq sequencing platform and amplicon sequence variant (ASV)-based bioinformatics pipeline to generate high-resolution data that discriminate sequences down to a single nucleotide difference.
A parasite community of 45 ASVs corresponding to 23 species consisting of 4 genera of Babesia, Theileria, Hepatozoon and Colpodella, were identified in wildlife and the cattle population from the study area. Theileria species were detected in buffalo, impala, hartebeest, sable antelope, sitatunga, wild dog and cattle. In contrast, Babesia species were only observed in cattle and wild dog. Our results demonstrate possible spillover of these hemoprotozoan parasites from wildlife, especially buffalo, to the cattle population in the wildlife-livestock interface.
We demonstrated that the deep amplicon sequencing of the 18S rRNA V4 hyper-variable region for wildlife was informative. Our results illustrated the diversity of piroplasma and the specificity of their hosts. They led us to speculate a possible ecological cycle including transmission from wildlife to domestic animals in the greater Kafue ecosystem. Thus, this approach may contribute to the establishment of appropriate disease control strategies in wildlife-livestock interface areas.
梨形虫是一种经媒介传播的、感染野生动物和家畜的细胞内血原虫寄生虫。野生动物是多种梨形虫的储存宿主,在这些寄生虫的传播、维持和进化中发挥着重要作用。当存在有媒介传播能力的媒介时,野生动物和家畜共享一个共同的生态位,这突显了来自野生动物的病原性和非病原性梨形虫寄生虫向家畜溢出的可能性。
为了调查大卡富埃生态系统中的野生动物和牛群中的梨形虫多样性,我们利用 PCR 扩增 18S rRNA V4 超可变区,并采用 Illumina MiSeq 测序平台和基于扩增子序列变异 (ASV) 的生物信息学管道进行元条形码策略,生成能够区分到单个核苷酸差异的高分辨率数据。
在研究区域的野生动物和牛群中,共鉴定出 45 种 ASV,对应 23 个种,包括 4 个属的巴贝斯虫、泰勒虫、肝孢子虫和柯氏巴贝斯虫。在水牛、黑斑羚、角马、薮羚、捻角羚、野狗和牛中检测到泰勒虫。相比之下,只在牛和野狗中观察到巴贝斯虫。我们的结果表明,这些血原虫寄生虫可能从野生动物,特别是水牛,向野生动物与家畜的交界处的牛群溢出。
我们证明了对野生动物的 18S rRNA V4 超可变区进行深度扩增子测序是有信息的。我们的结果说明了梨形虫的多样性及其宿主的特异性。它们使我们推测在大卡富埃生态系统中可能存在包括从野生动物到家畜的传播的生态循环。因此,这种方法可能有助于在野生动物与家畜的交界处建立适当的疾病控制策略。