The Virulence And Difference Of The ROP5 And ROP18 Protein Sequence Of The Dominant Genotype Toxoplasma Gondii In China

Objective To analyze the differences in protein sequences between the dominant gene Chinese 1,Toxoplasma gondii WH3 strain,Wh6 strain,ROP5 and ROP18 related virulence factors,so as to lay the foundation for studying their pathogenic mechanism.Methods The recovery will be kept in this laboratory respectively WH3 and RH strains of Toxoplasma gondii were inoculated with 4-6w Kunming mice.After acute onset,the ascites were collected and the WH3 and RH strains were purified respectively.Wh6 and PRU strains of Toxoplasma gondii cysts were isolated from the brain of Kunming mice raised in this room,respectively.After inoculation of 4-6w age Kunming mice,the ascites were collected and the tachyonus of WH6 and PRU strains were purified after acute onset.The above 4 strains of 1*103 tachycolonies were infected with 40 SPF BALB/c mice and 40 Kunming mice,respectively.The survival time and survival rate were observed.Analyze the strength of virulence.The total RNA of these 4 Toxoplasma gondii was extracted and transcribed to c DNA,and PCR was used to amplify the ROP5 and ROP18 length of Toxoplasma gondii protein family.The sequence of PCR products was sequenced,and the sequence was transformed from nucleotide sequence to amino acid sequence,and the difference of genetic sequence of the protein level was analyzed and compared.Results 4 strains of Toxoplasma gondii strains,toxicity to both BALB/c and Kunming mice strong Chinese 1 genotype WH3 strains and genotype I RH strains in BALB/c mice infected with WH3 strain and RH strain were 100% death after 5-7 d,and Kunming mice survived slightly longer than BALB/c mice(?2 = 17.75,p < 0.0001,?2 = 18.04,p < 0.0001),but also to were all dead until the 12 d from infection of T.gondii;After infected WH6 and PRU strains,BALB/c mice and Kunming mice did not appear the phenomenon of illness and death,two mice at 45 d after infection were 100% in survival,and cysts detected in the brain.After infection with T.gondii Wh3 strain and RH strain in BALB/c mice and Kunming mice,there was no significant difference in virulence between two insect strains in the same strain mice(?2 = 0.4303,p = 0.5118,?2 = 1.511,p = 0.2191).PCR amplification of ROP5 gene and ROP16 gene sequences were obtained,and the expected results of the same size fragment sequencing and nucleotide sequences into amino acid sequence alignment showed that Chinese 1 genotype WH3 strain and Wh6 strain and PRU strain(II strain)and the difference is small,and the virulence of type RH insect strong strain(I type strain difference).Conclusion The virulence of the dominant genotype Chinese 1 of Toxoplasma gondii WH3,was equivalent to the RH strain of the genotype I,and the virulence of Wh6 strain was the same as that of the PRU strain of the genotype II.The virulence related molecules ROP 5 and ROP18 of the Chinese 1 genotypes Toxoplasma gondii were different from the traditional genotype I and II strain.Two strains of WH6 strain had high homology with II strain(PRU strain),and WH3 strain II strain(PRU strain)had little difference,which was different from virulent I strain(RH strain).The homology of virulence related molecules between Chinese 1 genotypes and Toxoplasma gondii strains is inconsistent with virulence differences,suggesting that more effective molecules are involved in virulence.