EN
The presence of potential vectors, ticks, and susceptible hosts of bovine malignant theileriosis in all parts of Iran pose a real threat to food animal industry. The present study was conducted to determine the infection rate of ticks collected from naturally occurring bovine theileriosis in West and North-West Iran. Two hundred and thirty seven cattle suspected of suffering from theileriosis were investigated for the presence of Theileria annulata in the blood smears and any tick species on their body. In this study, 402 ticks were obtained from 99 cattle. The examination of 402 ticks by polymerase chain reaction (PCR) using primers derived from the gene encoding heat shock protein70 (Hsp70) revealed that 39.9% of Hyalomma anatolicum anatolicum, 3.5% of H. asiaticum asiaticum, and 18.2% H. anatolicum excavatum, were infected with T. annulata. The results suggest that H. a. anatolicum may play a major role in transmission of T. annulata infection in Iran. Finally, digestion of the PCR products of T. annulata with two different restriction enzymes produced only a single pattern.