Molecular detection of Theileria annulata in dairy cattle and vector ticks in the Herat area , Afghanistan

Document Type: Original Articles

Authors

Department of pathobiology, Faculty of Vetrinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran

Abstract

Theileriosis is one of the most important diseases in tropical and subtropical regions and is caused to annual economic losses such as the reduction of dairy products and casualties. Despite observe the clinical form of bovine theileriosis in Afghanistan, no comprehensive study has been conducted on this issue. From June 2015 to September 2016, a molecular survey was done for identification Theileria annulata and tick vector in dairy cattle in the Herat area, Afghanistan. A total of 100 dairy cattle were clinically examined and collected blood smears, EDTA blood samples, and ixodid ticks. The blood samples were transported to the laboratory, then prepared the blood smears and stained with the Giemsa method. The collected ticks were identified at the species level using the identification key. The collected ticks were separated into 70 tick pools according to their species. Then, the salivary glands were dissected out in 0.85% saline under a stereomicroscope. DNA of blood and salivary glands was extracted using a commercial kit and analyzed by PCR. The ring form of Theileria spp infection was observed in 22 (22%) of blood smears, while 74 % of blood samples were T.annulata positive by using PCR. Among collected ticks, the number of male and female ticks was 219 ticks and 130 ticks, respectively. The frequency of tick species was followed by Hyalomma annatolicum (73.9%), Hyalomma excavatum (22.3 %), Hyalomma asiaticum (1.1%), Hyalomma marginatum (1.7%), Hyalomma rufipes (0.75%) and Hyalomma nymph spp (12%). The PCR results showed that seven pools belong to salivary glands of H. anatolicum were infected with T.annulata. Based on the obtained results, it is concluded that T.annulata had a high frequency in dairy cattle and H.anatoloicum was identified such as the vectors of T.annulata in the Herat area, Afghanistan.n.

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