Molecular Detection And Identification Of Cryptosporidium Of Sheep In Some Large-scale Farms In Southern Xinjiang

Cryptosporidium spp.is a zoonotic diarrhea pathogen that is widely spread in the world.As an important storage and transmission host of Cryptosporidium,Sheep are caused by diarrhea,growth and production performance decline after infection.Sheep even death in severe cases.Studies indicate that,previous studies have confirmed a risk of zoonotic infection of sheep Cryptosporidium.Sheep breeding is one of the pillar economic industries in southern Xinjiang.However,there are less data on the epidemiology of Cryptosporidium in this region and,the risk of Cryptosporidium transmission from sheep can not be effectively assessed.In this paper,the infection of Cryptosporidium in sheep in large-scale farms in some areas of southern Xinjiang was detected and identified by nested PCR.To provide the theoretical basis for the prevalence and genotype distribution of Cryptosporidium in sheep in Xinjiang.(1)Based on the SSU r RNA gene locus of Cryptosporidium,1,252 fecal samples of sheep from 10 large-scale sheep farms in southern Xinjiang were detected,and 100 samples were positive for Cryptosporidium,with a total infection rate of 7.99 %(100/1252).Cryptosporidium was positive in 9 of 10 large-scale sheep farms,and the infection rate ranged from 3.33 %(3/90)to 18.4 %(23/125).The infection rate of Cryptosporidium in sheep at different ages was negatively correlated with their age.Among them,the infection rate of Cryptosporidium in lambs weaned at less than 3 months of age was the highest 20.27 %(61/301).The infection rate of Cryptosporidium in lambs weaned at 3-6 months of age was 10.33 %(34/329).The infection rate of Cryptosporidium in Sheep in their youth aged 6-12 months and sheep in the adult stage aged more than 12 months was 0.92 %(3/327)and 0.68 %(2/295),respectively.The infection rate of Cryptosporidium in sheep of different ages was significantly different(χ~2= 107.897,P = 0.000).By sequencing,there were three species of Cryptosporidium in 100 positive samples,which were Cryptosporidium xiaoi(n = 61),Cryptosporidium parvum(n = 22),and Cryptosporidium ubiquitum(n = 17).Based on the gp60 gene subtype analysis,Cryptosporidium parvum contains two subtypes,IId A15G1(n = 1)and IId A19G1(n = 21).All Cryptosporidium ubiquitum positive samples were XIIa.The results showed that Cryptosporidium infection was common in sheep in some large-scale farms in southern Xinjiang,and there were zoonotic species and subtypes of Cryptosporidium infection.(2)Based on six microsatellite and microsatellite loci(DZ-HRGP,RPGR,MSC6-7,Mucin-1,MSC6-5,ZPT)of Cryptosporidium parvum,multilocus sequence analysis(MLST)was performed on 22 Cryptosporidium parvum positive samples,and 16,15,15,15,and 16 positive samples were amplified from each gene locus.gene loci formed 3,3,2,2,3,and 1 genotypes were formed at the above gene loci,and 7 polymorphic genotypes(MLGs,MLGs1-MLGs7)were obtained by sequence tandem analysis.The results suggest that the multilocus typing of Cryptosporidium has a higher resolution than gp60 locus typing,and there is a genetic diversity of Cryptosporidium parvum in southern Xinjiang.In conclusion,this study found that Cryptosporidium infection in sheep is common in large-scale farms in southern Xinjiang,and there are zoonotic species and subtypes.Cryptosporidium parvum is characterized by intraspecific genetic differentiation.The results of this study will provide basic data for the epidemiological study of sheep Cryptosporidiosis in China.