Studies On Coccidial Species And Molecular Characterization Of Cryptosporidium Andersonf In Qinchuan Cattle In Guanzhong Area

Coccidia and Cryptosporidium can cause diarrhea, weight loss and even death, which aretwo of the most important worldwide parasitic protozoa. Cryptosporidium is gastrointestinalprotozoan of various animals, including livestock, birds, and wild animals. Cryptosporidiumis a significant factor of chronic lethal diarrhea, and humans, especially children andimmunocompromised people. Human can aquire Cryptosporidium infection through severalroutes, such as direct contact with infected person (person-to-person transmission) or animalsand ingestion of contaminated food and water. Cryptosporidiosis is parastic a zoonosis,causing huge economic loss in animal husbandry. But currently, there is no effective drug orvaccine for the disease. Grasping of the epidemiology of bovine cryptosporidiosis will helpcontrolling the breakout of the disease. Therefor, the prevalences of bovine coccidiosis andthe cryptosporidiosis and the species identification of Cryptosporidium from molecular levelwere investigated in the presnt study.1Fecal samples were examined by flotation technique using saturated saline. Theinfection rates of coccidial oocysts were45.61%and41.38%for dairy cattle and Qinchuancattle. The highest was found in weaned calves (3～12months), and the lowest occurred ingroup of pre-weaned calves. There is significant difference in coccidial infection in differentage groups.12Eimeria speciese (namely, E. subspherica, E. ellipsoidalis, E. zurnii, E. pellita,E. bovis, E. canadensis, E. bukidnonensis, E. cylindrica, E. auburnensis, E. brasiliensis, E.bombayansis, E. alabamensis) and one Isospora species (only found in Qinchuan cattle) wereidentified. The predominant species is E. bovis.2Sheather’s sugar flotation technique was used to detect the Cryptosporidium oocysts infeces of Qinchuan cattle. Microscopic examination showed that the average infection rate ofCryptosporidium spp. was4.2%(33/783). The highest infection rate was found in3-12months-old calves, and the lowest occurred in group of above2-year-old。There issignificant difference in Cryptosporidium infection in different ages of cattle, but there is nodifference in areas, or seasons. Cryptosporidium samples were identified as C. andersoni byPCR and restriction fragment length polymorphism (PCR-RFLP). The18S rDNA sequencingresults showed that the homology reached100%compared with corresponding sequences inGenBank. C. andersoni is the predominant Cryptosporidium spp. in Qinchuan cattle, Guanzhong area. Subtyping of C. andersoni was conducted by multilocus sequence typing(MLST) techque based on minisatellite sequences of MS1, MS2, MS3and MS16genes, andthe MLST subtype （3,4,4,1）was the predominant subtype of C. andersoni in Qinchuancattle. The single species and subtype showed that C. andersoni in Guanzhong area had a lowgenetic polymorphism.