Identification of Theileria Species in Sheep and Vector Ticks Using PCR Method in Zabol, Eastern Iran

BACKGROUND: Theileria is a protozoal parasite that belongs to the phylum Apicomplexa. Theileriosis is an important tick-borne disease caused by various species of Theileria. Among these species, T. lestoquardi (T. hirci) is highly pathogenic, while other species such as T. ovis make Subclinical and mild infections in small ruminant. Therefore, the precise identification of the species and the vector ticks are very essential for epidemiological studies and the design of control programs. METHODS: This research was conducted with the aim of molecular study to identify Theileria species and vectors in Zabol, eastern Iran in 2015. The presence of Theileria in 80 blood samples and vector ticks was evaluated using PCR method. RESULTS: Of 80 blood samples, PCR analysis showed that 50 samples (62.5%) were infected with Theileria. The evaluation of the first phase PCR with Nested PCR showed that infections with Theileria ovis and Theileria lestoquardi were 67.45% and 32.55% cases respectively. Overall, 110 ticks (78 males and 32 females) were collected and generally two genera and six species including Rhipicephalus bursa (9.1%), Rh. sanguineus (29.1%), Rh. turanicus (10.9%) Hyalomma asiaticum asiaticum (23.63%), Hy. excavatum (10.9%), Hy. anatolicum (16.37%) were detected. After evaluating ticks infection by PCR method, three species of Rh. turanicus, Rh. sanguineus and Hy. asiaticum asiaticum, were infected. CONCLUSION: Theileria ovis has a high prevalence among the sheep of zabol and Hy. asiaticum asiaticum, Rh. sanguineus and Rh. turanicus may be the main vectors of Theileria species in this area.