Genotyping Of Toxoplasma Gondii From Pig In Some Areas Of Henan Province And The Culture Of T.gondii Rh Strain In Vitro

Toxoplasmosis is caused by Toxoplasma gondii that is an obligate intracelular protozoan pathogen. T. gondii can infect various animals, including humans,especially is of the high morbidity and mortality in swine.Toxoplasmosis has complicated clinical symptoms because T. gondii can infect different tissues,which causes inconvenience in diagnosis and prevention in early phases.Therefore, it is important to develop a more effective method to diagnose Toxoplasmosis.T. gondii has a widely hosts, and it shows different biology characteristics in different hosts. Therefore,the study on genetics and epidemiology of T. gondii is of importance for prevention and treatment. In the past, the determination of genotypes of T. gondii strains based on pathogenicity in mice which discriminated virulent strains from avirulent strains.With the rapid development of molecular genetics, genetic typing methods of T. gondii strains have been extensively performed in the recent years. Typing,virulence and distribution of different T. gondii strains in the level of molecular genetics divides all strains into multiplex genotypes and makes us know the regular pattern of genotypes with different districts and hosts.The diagosis for T. gondii in the molecular genetics will provide effective steps to prevent it.1. In order to find positive strain of Toxoplasma gondii in Henan Province, the author randomly collected some samples from different districts and the application of my laboratory established nested PCR method to investigate molecular epidemiology, through the PCR method to find positive cases. The results showed that 31 samples was positive in collected 1647 samples,and the avergage positive rate of T. gondii were 1.88% in some areas of Henan province.2. The efficient culture of T. gondii in vitro is necessary for futher study on this pathogen, and provide a powerful tool for investigation of the invasion of T. gondii and its mechanism of immune evasion, and the diagnosis of T. gondii in breed diseases. MDCK cells were used to culture tachyzoites of T. gondii. After inoculation 12h, various stages of T. gondii and MDCK cells on the coverslip in a Petri dish were treated with xylene and Giemsa stain to check the growing status of the parasites, and then were observed under the microscope and taken Photographs. The results demonstrated that T. gondii was able to effectively infect MDCK cells.3. In order to understand the genotype of the isolates, a multiplex PCR assay was designed for genotyping of T. gondii strains based on polymorphism of five microsatellite markers:TuB2, W35, TgM-A, B18 and B17. Results indicated that RH strains was genotype I, which is identical with the result previously reported. While other 31 isolates from Henan province were novel genotype.