Molecular Characteristics And Phylogenetic Relationship Of Cryptosporidium And Giardia Isolates From Dogs In Some Areas Of SiChuan Province

Cryptosporidiosis and Giardiasis are important opportunistic pathopoiesis protozoan parasites, which are serious threats to human beings and animals, they are also prevalent in the world. Cryptosporidium can infect at least 260 species of vertebrate, it mainly cause diarrhea of human beings and animals, especially in people who suffered immune-deficiency and hypoimmunity,the worst can lead to death.The Giardia, distributed in worldwaid, is frequent pathogency of diarrhea.It had been popular in the international travelers, so it known as "traveler's diarrhea" and it is one of the world's 10 kinds of major parasitic diseases which threated to human beings in the world. Both of the Cryptosporidium and the Giardia can spread and infect by many ways. We usually know food and water are major source of infection that is polluted by oocyst and cyst.The companion-animals are easy to carry and spread these pathogens, which have a potential threat to human beings.Based on the study of Molecular characterization of Cryptosporidium, dogs can be infected with C.canis, C.parvum, C.muris and C.meleagridis, which are the extremely potential to infect human beings and animals.many research showed that dogs are easy to infect giardia and can carry different assemblage of giardia. There is apparent positive correlation of infection rate between Giardia canis and people in a family. Following the economic development of society, there are more and more direct or indirect contact between people and companion-animals and the pathogen of amphixenosis is a potential threat to human beings'health. In order to understand the infected information of dogs'cryptozoite and giardia, estimate its significance of public health, the study carry out an investigation on dogs'intestinal parasites in some areas of Sichuan, using molecular biology methods to identify and anylysis insect species and genes of cryptozoite and giardia. 1. The 494 Specimens, which got from three dogs field, two animal hospital, one rescue shelter and one Experimental animals room of jianyang, Chengdu, Jian yang and ya'an in Sichuan province, were collected and examined by microscope of iodine wet mount smears and concentrated, sucrose density gradient centrifugation and formalin-acetidin cntrifagal precipitation methodwe found 182positive samples, the parasites'total infection rate was 36.8%. Dogs' coccidian infection rate was the highest,which was 26.9%,the infection rate of dogs'Cryptosporidium, Giardia, ascarid, flukes, strongyld, hookworms, whipworm, and tapeworm was 4.3%,17.4%,9.7%,1.8%, 8.9%,6.3%,0.4% and 6.5% respectively. The investigation provided reference to protect and control parasitosis of pet and stray dogs.2. Amplifing 18S rRNA PCR-based gene to recover a length of approximately 830bp fragment, using Sspl and VspI enzymes to RFLP-PCR analyze, choosing 4 isolation strains to procee sequence and using biology software to compare with sequence,builded cladogram and analyzed homology by Clustal X1.81, phylip 3.67, DNAstar4.0 and so on. The result of digestion suggested that the 19 isolation strains were C.canis, the result of sequence analysis suggested that the homology of 4 isolation strains and C.canis which was downloaded from GenBank that was 100%.3. Based on the TPI gene, we amplified 86 isolation strains of giardia and received 530bp purpose fragment.choosing 12 isolation strains to procee sequence, the result of sequences'comparison suggested that was giardia C of separated giardia.4. The study investigated the infection's information of dogs' cryptosporidium and giardia in some areas of Sichuan province, and used molecular biology method to analyze molecule's hereditary feature and identified genotype of cryptosporidium and giardia.Cryptosporidium was amphixenosis and giardias' genotype was unique to dogs,these showed that dogs were potential threat to human beings'health, we should strengthen the prevention and control of amphixenosis. The study initial master the epidemic dynamic stste and molecular hereditary feature of dogs'cryptosporidium and giardia in some areas of Sichuan Province, which established basis for a further study.