Molecular detection of blood protozoa in ticks collected from cattle in the buffer zone of Sai Yok National Park, Thailand

Abstract

Ixodid ticks transmit many pathogens to both animals and humans. This study was carried out to detect tick-borne protozoa (Theileria and Babesia) in ticks collected from cattle in the buffer zone of Sai Yok National Park, Thailand. A total of 30 cattle were examined for tick infestation. Of these, 10 (33.3%) were infested with ticks. A total of 85 ticks were collected and identified as Rhipicephalus (Boophilus) microplus. The collected ticks were separated into 50 tick pools by sex and life stage. These pools were examined for Theileria and Babesia species by polymerase chain reaction (PCR) for amplification of a fragment of the 18S ribosomal RNA (rRNA) gene. Of the 50 tick pools examined, 9 (18%) were infected with the Theileria species; of this group, 8 (88.9%) shared 100% identity with the unidentified Theileria sp., whereas 1 (11.1%) shared 99% identity with T. orientalis/sergenti/buffeli. In the phylogenic tree, unidentified Theileria sp. was closely related to T. sinensis and was clearly separated from other Theileria species. This study is the first report of R. microplus infected with the bovine Theileria species in Thailand conducted using molecular identification techniques.