Epidemiological Survey Of Tick Borne Bovine Theileriosis From Three Farm Of Bazhou Yak

Tropical theileriosis is a tick-borne hemozoon disease characterized by Theileria annulata of Theileriidae,Theileria attacks erythrocytes,lymphocyte and macrophagocyte in bovine.The infection rate is as high as 35～60% in some pastures and the mortality rate is 46.4 %,which is seriously restricts the development of local economy.In this paper,suspected pathogenic yak blood samples(anticoagulant sample N=304,serum sample N=304)and ticks(N=1782)were collected from three research sites(yak farm in Wulasitai village,Bayanbulak village,Hoxud county)in Bazhou,the main produce area of yak.With the help of the stereoscopic microscope,the species identification of media tick was finished based on morphological character and gene sequencing to identified molecular biological,and the dominance of ticks and the tick index were statistically analyzed.The blood samples were detected by PCR and ELISA,and the epidemic situation of the disease was analyzed.The results will provide scientific basis for the comprehensive prevention and control of vector ticks and their transmitted diseases in yak main produce areas.(I)In this experiment,1782 Ixodes were collected from above mentioned three experimental areas,and observed by morphological microscope(stereoscopic microscope)and identified by morphology.The specific primers were synthesized by PCR amplification and sequencing by the tick COI gene,and molecular biological identification was carried out.The results showed that 1782 Ixodes were collected and 5 species of ticks belong to 2 genera,Dermacentor nuttalli 424,Dermacentor niveus 499 and Dermacentor silvarum 324;Hyalomma detritum 209 and Hyalomma anatolicum 326.Based on the PCR amplification of COI gene,the target band of 700 bp was amplified,and Gen Bank logged-in Dermacentor nuttalli,Dermacentor niveus,Dermacentor silvarum,Hyalomma detritum and Hyalomma anatolicum(Sequence ID: KU594271.1,JQ737080.1,JQ737078.1,EU827695.1,KM235701.1)COI gene sequence homology of 99.00%,99.00%,99.00%,99.00%,99.00%;The relative dominance of Dermacentor niveus was 28.00%;the tick index of Dermacentor nuttalli,Dermacentor niveus,Dermacentor silvarum,Hyalomma detritum and Hyalomma anatolicum,were 35.33,41.58,27.00,17.42 and 27.17 respectively.Yak infected with Dermacentor nuttalli,Dermacentor niveus,Dermacentor silvarum,Hyalomma detritum and Hyalomma anatolicum were 92.00%,92.00%,83.00%,50.00% and 75.00% respectively.during the investigation,it was found that yak pasture in the experimental site was grassland grazing type,which was interlaced with other domestic animals(sheep,cattle and horses)and frequently contacted,which provided favorable conditions for species richness and diversity of local yak parasite-vector tick community.(II)In this study,304 blood samples(304 blood samples for anticoagulant and 304 serum samples for each)were collected,according to Tams1 gene,specific primers were synthesized to detected anticoagulant by PCR,serum samples were detected by Bovine T.annulata ELISA KIT,and positive blood samples were screened and analyzed.The results showed that the positive rate of PCR was 25.00%(76/304),and ELISA was 25.66%(78/304).The coincidence rate of the two test methods was 97.43%,it shows that these two detection methods are suitable for the detection of yak tropical theileriosis.The positive rates of ELISA were 26.85%,27.00% and 22.92%,respectively,at the three experimental sites of yak farm in Wulasitai village,yak farm in Ba Yin village,yak farm of Hoxud county.The shrubs in the local area are suitable for quail breeding,staggered grazing,etc.,making it easily to spread the T.annulata,the yak pastures in Wulasitai village and the yak pastures in Bayanbulak village are high.