Real-time PCR for detection of Theileria equi and Babesia caballi parasites in ticks

Abstract

The tick, Dermacentor reticulatus is a vector for Babesia caballi and Theileria equi which cause equine babesiosis and theileriosis respectively. This study aimed to develop a real-time PCR screening test for Babesia caballi and Theileria equi in ticks. Adult D. reticulatus were collected from De Panne, Belgium. Nested PCR was used with B. caballi and T. equi specific adjacent hybridisation FRET probes to develop a qualitative real-time PCR. The test was used to screen DNA extracts from collected ticks. Probe sequences were based on differences in the 18S rRNA gene of the pathogens. DNA extracts from known Theileria and Babesia spp. were used as positive controls. Using melting curve analysis probes were able to detect and distinguish the B. caballi and T. equi positive controls. None of the tick samples tested positive for T. equi and B. caballi but one sample was positive for T. parva. This test is suitable for application in epidemiological surveillance of equine babesiosis and theileriosis.

Keywords: Dermacentor reticulatus; Babesia caballi; Theileria equi; real-time PCR; FRET probe