Molecular detection and characterisation of Theileria in hard ticks of small ruminants in Zarrin Dasht County, Southern Iran

BACKGROUND: Ticks are important ectoparasites of small ruminants in tropics and subtropics including Iran. They transmit serious zoonotic pathogens such as Babesia and Theileria. These parasites cause major burden on small ruminants jeopardising livelihoods of rural people in Zarrin Dasht County. OBJECTIVES: This study was carried out to investigate the diversity and distribution of hard ticks of small ruminants and their piroplasm infection in a bid to contribute to Theileria and/or Babesia detection and control in Zarrin Dasht County of Fars province, Iran. METHODS: We examined 751 sheep and goats from 10 sites of the County during four seasons for hard tick infestation. The collected hard ticks (994) were taxonomically identified before being separately confined in microtubes coded to indicate their species and host animals as well as site and date of collection. In total 50 pooled samples were analysed by PCR technique for Theileria and Babesia infection. RESULTS: The identified ticks included Hyalomma marginatum 994/362); 36.4%), Rhipicephalus turanicus 994/352); 35.51%), Hyalomma anatolicum 994/264); 26.6%), Hyalomma dromedarii 994/14); 1.41%) and Hyalomma asiaticum 994/2) 0.2%). Molecular analyses showed that 7 out of 50 pooled sample were infected with piroplasm genome in ticks shared by Theileria ovis (6:50) and Theileria lestoquardi (1:50). Babesia was absent in collected hard ticks. CONCLUSIONS: This is the first report on the presence of piroplasm infection in hard ticks of small ruminants in Zarrin Dasht County. Theileria ovis was more prevalent than Theileria lestoquardi but Babesia was absent. Piroplasm infection was detected in Hyalomma marginatum, Hyalomma anatolicum and Rhipicephalus turanicus. Hyalomma marginatum appears to be more competent to vector Theileria spp. This study may contribute to risk assessment and prevention of epizootic theileriosis in the County.