First report on the occurrence of Theileria sp. OT3 in China

- A newly isolated Theileria sp. OT3 in China was identified based on the 18S rDNA gene.
- First to amplify the internal transcribed spacers of Theileria sp. OT3
- The phylogenetic tree of Babesia and Theileria species was analyzed based on the ITS.
- Species-specific diagnostic method was developed.
- Potential transmission vectors of Theileria sp. OT3 were detected.

Theileria sp. OT3 was firstly detected and identified from clinically healthy sheep in Xinjiang Uygur Autonomous Region of China (XUAR) through comparing the complete 18S rDNA gene sequences available in GenBank database and the phylogenetic status based on the internal transcribed spacers (ITS1, ITS2) as well as the intervening 5.8S coding region of the rRNA gene by the methods of a partitioned multi-locus analysis in BEAST and Maximum likelihood analysis in PhyML. Moreover, the findings were confirmed by the species-specific PCR for Theileria sp. OT3 and the prevalence of Theileria sp. OT3 was 14.9% in the north of XUAR. This study is the first report on the occurrence of Theileria sp. OT3 in China.