In Vitro Virulence Contrast of Seven Genetically Distinct Toxoplasma gondii Isolates After Rejuvenation In Vivo

Background In the past for more than 100 years at least 300 genotypes of Toxoplasma gondii were recorded and several traditional isolates such as RH, GT1, ME49, PRU and VEG were used repeatedly to clarify the pathogenic mechanisms and the epidemiological significance to human, but for if their virulence was mutative post-iterative passages it remains confused. Objective Therefore, in the study, seven genetically distinct T. gondii including C7 and PYS previously discovered in China were reidentified by sequencing the head of hsp40 locus to distinguish their virulence in vitro post-rejuvenation in vivo . Results Our data showed the nucleotides were different in 18 positions and 7 of them can be used to type T. gondii isolates. Total 634 plaques of T. gondii without two or more overlaps indicated that RH and GT1 tachyzoites possess stronger power than other five isolates in vitro ( p