Abstract：
The genetic variability of apicomplexan parasite Babesia species is a principal strategy used by piroplasma to evade their hosts\' immune responses. The purpose of this review was to evaluate our current knowledge on global haplotype distribution and phylogeography of Babesia ovis derived from sheep, goat, horse and ixodid (hard) ticks. Bibliographic English databases were searched from 2017 to 2023, identifying a total of 11 publications. The 18S ribosomal RNA (18S rRNA) sequences of B. ovis from Asia, Europe, and Africa were retrieved and subjected to estimate the genetic diversity and phylogenetic assessment. A haplotype network indicated a total of 29 haplotypes being classified into two distinct geographical haplogroups I and II including Nigeria and Uganda-derived B. ovis isolates. A moderately high level of genetic diversity was characterized in sheep/tick-derived B. ovis isolates originating from Iraq (Haplotype diversity: 0.781) and Turkey (Hd: 0.841). Based on the cladistic phylogenetic tree, two geographically different lineages of A and B were genetically differentiated except for Turkish isolates, indicating haplotype migration occurred between various geographical clades. In addition, the topology of UPGMA tree indicated that B. ovis population has a distinct clade compared to the rest clades of ovine babesiosis (B. crassa and B. motasi). The present results strengthen our knowledge to evaluate the evolutionary paradigms and transmission dynamics of B. ovis in different regions of the world; also it will provide groundwork for public health policy to control ovine babesiosis.
摘要：
顶复体寄生虫巴贝斯虫物种的遗传变异性是piroplasma用来逃避其宿主免疫反应的主要策略。这篇综述的目的是评估我们目前对来自绵羊的Babesiaovis的全球单倍型分布和系统地理学的了解，山羊,马和ixodid（硬）蜱。从2017年到2023年检索了书目英语数据库，共确定了11种出版物。来自亚洲的B.ovis的18S核糖体RNA（18SrRNA）序列，欧洲,对非洲进行了检索，并进行了遗传多样性估计和系统发育评估。单倍型网络表明，总共有29个单倍型被分为两个不同的地理单倍型I和II，包括尼日利亚和乌干达衍生的念珠菌分离株。在源自伊拉克（单倍型多样性：0.781）和土耳其（Hd：0.841）的绵羊/tick衍生的双歧杆菌中，具有中等高度的遗传多样性。根据分类系统发育树，除土耳其分离株外，A和B的两个地理上不同的谱系进行了遗传分化，表明单倍型迁移发生在各个地理进化枝之间。此外,UPGMA树的拓扑结构表明，与绵羊巴贝斯虫病的其余进化枝相比，Ovis种群具有不同的进化枝（B.克拉萨和B.motasi)。目前的结果加强了我们的知识，以评估世界不同地区的B.Ovis的进化范式和传播动态；它还将为控制绵羊巴贝斯虫病的公共卫生政策奠定基础。
