Molecular detection of Theileria annulata and Theileria orientalis in cattle of Shahreza city, the south region of Isfahan province, Iran

Theileria are important hemoprotozoan parasites of cattle, transmitted by ixodid ticks leading to diseases which range from mild in apparent reactions to highly fatal diseases. This study aimed to determine the variety of Theileria species among cattle of Shahreza city, the south part of Isfahan Province. A total of 253 blood samples were randomly collected via the ear vein and jugular vein from healthy cattle for microscopy and molecular examination, respectively. The extracted DNA from blood cells was amplified by Theileria-all primers, which amplify an approximately 400bp DNA fragment from the region of the 18S rRNA gene from various members of the genus Theileria. All cattle positive samples were further analysed for the presence of Theileria annulata and Theileria orientalis by specific semi-nested PCR. T. annulata and T. orientalis were identified by specific semi-nested PCR in 54.9% and 47% of cattle blood samples, respectively. Chi-square (x2) tests were used to compare molecular prevalence values relative to Season, Farm, Type, Hygiene, Vectors, Age, and Milk Yield. T. orientalis prevalence was significantly higher in cattle in summer as compared to those in other seasons (p < 0.05). The prevalence rates of T. orientalis in different seasons, hygiene levels, and vectors were significantly different (p < 0.05). T. orientalis prevalence was higher in spring, farms with tick vectors and normal level of Hygiene. The examination of 50 microscopic fields showed 14.39% sensitivity and 99.12% specificity compared to molecular examination. The Kappa coefficient between molecular and microscopy (50 fields) techniques indicated a poor level of agreement (Kappa= 0.124). This study is the first molecular detection of Theileria species from cattle in the south of Isfahan province, Iran.