Investigation And Genetic Evolution Analysis Of Cryptosporidium Isolated From Birds In Zoos

Cryptosporidium is a kind of parasite protozoa which is distributed all over the world.It can infect human and many other vertebrates to threaten their health.Oocysts of Cryptosporidium can be transmitted through direct contact with infected people,animals or through polluted water and food,resulting in Cryptosporidiosis characterized by diarrhea,which poses a great threat to human health.So far,there is no effective drug for Cryptosporidiosis,so it is very important to study Cryptosporidium.Heilongjiang is the province with one of the largest land area and population in China.Beijing is an economically developed city with a large population flowing.However,there are relatively few studies on Cryptosporidiosis in these two areas.Therefore,this experiment intends to study Cryptosporidiosis in Harbin North Forest Zoo and Beijing Zoo.It provides theoretical basis for the control of Cryptosporidiosis of birds in China.In this study,45 species of birds from the Harbin North Forest Zoo and Beijing Zoo were selected as the research objects,and the infection,identification and genetics of Cryptosporidium were analyzed.In this study,the oocysts of birds' feces were floated by Sheather's solution and observed by microscope;the 18SrRNA gene of Cryptosporidium was amplified by nested PCR and sequenced.In 263 birds' feces samples,6 samples from Grus leucogeranu(4)and Phoenicopterus roseus(2)were positive,the positive rate was 2.28%(6/263).The infection rate of Cryptosporidium was 0%(0/69)in Harbin North Forest Zoo,3.09%(6/194)in Beijing Zoo,1.03%(2/194)in Phoenicopterus roseus,and 2.06%(4/194)in Grus leucogeranu.The sequence of Cryptosporidium obtained was analyzed with DNA Star,and the phylogenetic tree was constructed with Mega 6.0 after the comparison of clustal 2.0.Six Cryptosporidium strains(p 1,P 2,G 3,G 4,G 5,G 6)obtained from six positive samples of the phylogenetic tree were Cryptosporidium parvum.For the first time,this study found that Grus leucogeranu and Phoenicopterus roseus can infect Cryptosporidium parvum,which provides an important reference for understanding the biological characteristics,molecular epidemiology and genetic evolution of Cryptosporidium parvum in birds,and enriches the database of Cryptosporidium parvum infection in birds.