Common occurrence of Theileria annulata and the first report of T. ovis in dairy cattle from Southern Xinjiang, China

Bovine theileriosis is a common tick-born disease infected by Theileria spp. causing loss of beef and dairy cattle worldwide, therefore, the aim of this study was to determine the prevalence and genetic diversity of Theileria spp. in Southern Xinjiang Uyghur Autonomous Region, China. We screened 493 dairy cattle blood samples from Southern Xinjiang to detect Theileria spp. by PCR. The overall prevalence of Theileria spp. was 23.5% (116/493). The most frequent Theileria sp. was Theileria annulata 22.5% (111/493), followed by T. orientalis (0.6%, 3/493) and T. ovis (0.2%, 1/493). Additionally, one sample was co-infected with T. annulata and T. orientalis. Phylogenetic analysis showed that the 11 T. annulata Tams1 sequences grouped into three sequence clusters that belonged to group 2 (Asia group) and shared 96.4% to 99.9% identity with to each other. Furthermore, our results revealed the presence of several T. orientalis MPSP genotypes (types 1, 2, and 5) in this region. In this study, T. annulata was found to be the most prevalent Theileria species in dairy cattle from Southern Xinjiang. Theileria ovis was detected in one DNA sample of a free-grazing dairy cow from China for the first time.