Infection Investigation And Molecular Identification Of Sarcocystis From Diaphragm Of Tibetan Sheep In Parts Of Qinghai Province

Using the tabletting microscopy to examine the Sarcocystis infection in 181 Tibetan sheep diaphragm from eight country of Qinghai province, including Zeku, Wulan, Gonghe, Guinan, Haiyan, Huzhu and Hualong County. The results showed that 141 sheep were positive for cysts of Sarcocystis species. The highest infection rate was found in Wulan and Huzhu County(100%). The highest infection intensity was368(14~1296)per gram tissue,the the lowest infection intensity was 4(2~6) per gram tissue. The average cysts size was 0.35(0.15~1.20)mm×0.05(0.04~0.13)mm. These findings suggest that attention should be paid to prevention and treatment of Sarcocystis in Tibetan sheep from Qinghai province.The cyst shape was spindle~shaped by HE staining. Using scanning electron microscope to observe cyst ultrastructure. It is like spindle~shaped by rip cutting, like pea~shape by crosscut. The cyst wall, about 5μm, is consisting of primary cyst wall and secondary cyst wall. The primary cyst wall is smooth whereas the secondary cyst wall is roughness. The cyst cavity was divided into many rooms which contains banana~shaped bradyzoite by separation which strech from ground substance. It is identified as Sarcocystis cystiformis according these features.PCR method based on 18 S r RNA gene was used to amplify different Sarcocystis positive samples, the obtained sequences were aligned and analysed to further verify which species of Sarcocystis were in these examined sheep. The results of phylogenetic relationship analysis confirmed that Sarcocystis tenella was present in herds of sheep in some areas of Qinghai province.