Determination of infestation rate of Ixodidae ticks to Theileria annulata in Urmia region by polymerase chain reaction (PCR)

Abstract

Theileriosis is one of the most important protozoan parasitic diseases in Iran that causes economic losses and mortality in livestock. The disease is transmitted by Ixodid ticks and is characterized by fever, anemia, anoxia and eventually death. Diagnosis of the disease was previously based on staining of blood and lymph node samples by Giemsa method. The use of molecular methods is preferred over previous methods due to their high sensitivity and specificity. Due to the fact that Ixodid ticks that can carry the disease are found in many traditional Iranian farms, it is very important to identify and introduce these ticks. The aim of this study was molecular identification of Theileria annulata infection in ticks isolated from cows in Urmia region. A total of 100 ticks from herds with a history of Theileria annulata infection in the area were collected and transferred to the laboratory. Ticks were identified using diagnostic keys. Salivary glands of ticks were separated and analyzed by PCR after isolation using Theileria annulata specific primer (N516, N517). Out of 100 ticks, ten genera and species including Hyalomma anatolicum anatolicum (33%), Hy. detritum (16%), Boophylus anulatus (16%), Dermacentor marginatum (14%), Rhipicephalus bursa (9%), Hy. anantolicum excavatum (7%), D. niveus (4%) and Haemaphysalis punctate (1%) were identified. The predominant tick was identified as Hyalomma anatolicum anatolicum. PCR test showed the presence of 721 bp specific band on agarose gel in 62% of tick samples. The high rate of infection in vector mites in the area indicates their high potential for infection of cows with the agent of Theileria annulata.

Keywords

• cattle
• pcr
• theileria annulata
• tick
• urmia