Diagnosis of theileria annulata from suspected bovine with theileriosis in Qazvin province using microscopic examination and PCR

Bovine theileriosis is one of the most important parasitic diseases in Iran which causes severe economic losses through decreasing weight, milk production and increased mortality. The causative agent, Theileria annulata, is transferred by the ticks of genus Hyalomma. Diagnosis of theileriosis is based on clinical signs, microscopic examination. Nowadays, molecular biology methods like PCR are used for detection. Given the importance of bovine theileriosis, the aim of this study was diagnosis of T. annulata from suspected bovine with theileriosis in Qazvin province using microscopic examination and PCR. Out of 68 dairy cattle with clinical symptoms were taken from blood samples. Then the blood smear was prepared and stained with Giemsa dye. Positive samples were incorporated for molecular studies. DNA of blood was extracted using phenol/chloroform/isoamyl alcohol and performed PCR using specific primers of Tams1 and 18S rRNA genes. Then, the PCR product of one sample was sequenced. Based on the obtained results, out of 68 in 28 (41.18%) blood samples was observed Theileria annulata by light microscopy, whereas all of the samples were positive by PCR.  BLAST analyses based on the 18S rRNA gene sequence of the Iranian isolate determined the 99.1% identity. Based on the obtained results, T. annulata had a high frequency in cattle of Qazvin province. It is suggested that further studies be conducted in this field in order to obtain more accurate estimates of disease in Iran.