Genotypes and Mouse Virulence of Toxoplasma gondii Isolates from Animals and Humans in China

Abstract

BackgroundRecent population structure studies of T. gondii revealed that a few major clonal lineages predominated in different geographical regions. T. gondii in South America is genetically and biologically divergent, whereas this parasite is remarkably clonal in North America and Europe with a few major lineages including Types I, II and III. Information on genotypes and mouse virulence of T. gondii isolates from China is scarce and insufficient to investigate its population structure, evolution, and transmission.Methodology/Principal FindingsGenotyping of 23 T. gondii isolates from different hosts using 10 markers for PCR-restriction fragment length polymorphism analyses (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) revealed five genotypes; among them three genotypes were atypical and two were archetypal. Fifteen strains belong to the Chinese 1 lineage, which has been previously reported as a widespread lineage from swine, cats, and humans in China. Two human isolates fall into the type I and II lineages and the remaining isolates belong to two new atypical genotypes (ToxoDB#204 and #205) which has never been reported in China. Our results show that these genotypes of T. gondii isolates are intermediately or highly virulent in mice except for the strain TgCtwh6, which maintained parasitemia in mice for 35 days post infection although it possesses the uniform genotype of Chinese 1. Additionally, phylogenetic network analyses of all isolates of genotype Chinese 1 are identical, and there is no variation based on the sequence data generated for four introns (EF1, HP2, UPRT1 and UPRT7) and two dense granule proteins (GRA6 and GRA7).Conclusion/SignificanceA limited genetic diversity was found and genotype Chinese 1 (ToxoDB#9) is dominantly circulating in mainland China. The results will provide a useful profile for deep insight to the population structure, epidemiology and biological characteristics of T. gondii in China.

Analysis Concentration of <i>Toxoplasma gondii</i> on Anti-Toxoplasma IgG-IgM Antibody Levels, and the Outcomes of Pregnancy in Mice Balb/c

“…There are three forms of T. gondii, they are tachyzoite (proliferative forms), cysts (containing bradizoit), and oocysts (containing sporozoite) [1] [2] [3] [4]. T. gondii consists of three types (type I, II and III) and two types from recombination (types IV and V) and has a different pathogenicity.…”

“…Nowadays, there are at least more than 120 genetic markers that have been developed and used for the determination of T gondii type [5] [6]. Toxoplasmosis is a zoonotic disease caused by T. gondii [4]. Toxplasmosis is an important zoonotic disease caused by protozoan parasite T. gondii.…”

Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections in stray and pet cats (Felis catus) in northwest China: co-infections and risk factors

“…Epidemiological data are necessary to define preventive, management, and therapeutical measures for stray, feral, and domestic cats. Although several studies have reported the T. gondii prevalence in cats in various regions in China (Dubey et al 2007;Chen et al 2011;Qian et al 2012;Wang et al 2013;Tian et al 2014), including Lanzhou (Wu et al 2011), little is known of the genotypes of T. gondii in cats in northwest China. Here, we investigated the genotypes of T. gondii in cats in northwest China for the first time.…”

Toxoplasmosis, zoonosis parasitaria prevalente en Chile: recuento y desafíos

“…La variación genética entre estos linajes es entre 1 y 3%, y la variación dentro de un linaje es muy baja (< 0,01) 40 . Las cepas con combinaciones atípicas se han aislado en presentaciones clínicas inusuales en humanos 41 , principalmente en Sudamérica (SA) 37 y en Asia 43 . Son desconocidas las causas por la cual estas cepas se encuentran confinadas sólo en ciertas zonas geográficas (SA).…”