Investigation On Five Intestinal Protozoa Infection In Tibetan Sheep In Qinghai Province And Its Population Structure Analysis

Tibetan sheep,one of the three primitive sheep species in China,is mainly distributed in the Qinghai-Tibetan Plateau.Its fur,milk,and meat are of high economic values,and are an important source of income for local herdsmen.In Qinghai Province,Tibetan sheep are usually raised in the way of house feeding and semi free-range.The local herdsmen generally drive the livestock to the alpine grassland when the natural grassland can provide sufficient forage for livestock.However,the feces on the grassland are not dealt with in a timely manner,making mutual infection of intestinal parasite among Tibetan sheep highly possible.Parasitoids parasitic protozoa tend to colonize in the intestines of human and various animals.The clinical symptoms of infected animals,therefore,are generally anorexia,anemia,diarrhea,and progressive emaciation.Parasitoids parasitic protozoa seriously affects the health of animals and becomes a key factor leading to the decline of animal growth and productivity.So,it is of great significance to understand the infection and population structure of various parasitoids protozoa in Tibetan sheep in Qinghai Province for the prevention and control of intestinal parasite infection.Based on PCR and nested PCR technology,a total of 761 samples were collected from seven places including Xining City,Haibei Tibetan Autonomous Prefecture,Hainan Tibetan Autonomous Prefecture,Haixi Tibetan Autonomous Prefecture,Haungnan Tibetan Autonomous Prefecture,Golog Tibetan Autonomous Prefecture,and Yushu Tibetan Autonomous Prefecture(hereinafter referred to as Xining,Haibei,Hainan,Haixi,Huangnan,Golog,and Yushu)to examine the prevalence of five parasitoids protozoa,and the phylogenetic relationship of the protozoa was analyzed on the basis of population structure,respectively.The results were as follows:1.The prevalence of Blastocystis in Tibetan sheep from Qinghai province was 10.12%(77/761),only four locations(Haungnan,Haixi,Yushu,and Haibei)were detected positive samples.Among them,the highest infection rate was in Haixi(62.75%),and the lowest in Haibei(2.34%),with highly significant difference(P<0.01).By seasons,positive samples were only detected in summer and autumn,with the infection rate being 31.13% and 4.20%,respectively,and the difference was highly significant(P<0.01).Three different subtypes were detected,ST14(33/77),ST10(15/77),and ST12(9/77).The rest 20 sequences had relatively low similarity(90%～82%)to existing subtypes,so it was failed to identify the subtypes.Among them,the ST14 was the dominant subtypes of Blastocystis in Qinghai Tibetan sheep.2.The prevalence of Cryptosporidium in Tibetan sheep from Qinghai was 3.68%(28/761),positive samples were detected in only four regions(Xining,Haibei,Hainan,and Huangnan),the highest infection rate was in Haibei(6.13%),and the lowest in Huangnan(2.80%),without statistical difference between different locations(P>0.05).By seasons,the highest infection rate was in summer(7.56%),and the lowest was in autumn(1.53%),with highly significant difference between four seasons(P<0.01).Four species were detected,C.xiaoi(13/28),C.ubiquitum(8/28),C.bovis(6/28),and C.ryanae(1/28).Among them,the C.xiaoi was the dominant species of Cryptosporidium in Qinghai Tibetan sheep.3.The prevalence of G.duodenalis in Tibetan sheep from Qinghai was 1.58%(12/761).Xining,Haibei,and Hainan were three places where positive samples were detected.The highest infection rate was in Xining(3.05%),and the lowest was in Hainan(1.61%),without statistically significant difference between those locations(P>0.05).By seasons,the highest infection rate was in spring(4.92%),while the lowest in winter(0),and highly significant difference was observed(P<0.01).Assemblage E(10/12)and Assemblage A(2/12)were detected,and the Assemblage E was the dominant genotypes of G.duodenalis in Qinghai Tibetan sheep.4.The prevalence of E.bieneusi in Tibetan sheep from Qinghai was 6.44%(49/761).Positive samples were detected in those places other than Golog,among which,the highest infection rate was in Xining(13.21%),and the lowest in Yushu(1.92%),with significant difference between different locations(P<0.01).By seasons,E.bieneusi was detected positive during all four seasons,the infection rates ranged between 13.21% and 0.96%,with highly significant difference(P<0.01).Five genotypes were detected,BEB6(21/46),COS-Ⅰ(14/46),CHS3(11/46),CGS1(2/46),and PIG EBITS5(1/46),of which the BEB6 was the dominant genotypes of E.bieneusi in Qinghai Tibetan sheep.5.The prevalence of Entamoeba in Tibetan sheep from Qinghai was 26.28%(200/761).Positive samples were detected in all of the seven locations,with the highest rate in Golog(58.82%)and the lowest in Hainan(16.13%).There was highly significant difference between different locations(P<0.01).As for seasons,the highest infection rate was in summer(37.74%),and the lowest was in winter(10.58%),with extremely significant difference between four seasons(P<0.01).Four species were detected,E.bovis(135/200),Entamoaba sp.MG107/BEL(54/200),Entamoaba sp.RL1(6/200),and Entamoaba sp.RL2(5/200).Among them,the E.bovis was the dominant species of Entamoeba in Qinghai Tibetan sheep.To sum up,this study elucidates the species and genotypes(subtypes)distribution of Blastocystis,Cryptosporidium,G.duodenalis,E.bieneusi,and Entamoeba in different regions of Qinghai province and different seasons,providing basic data for related research.