title: Genotypes and mouse virulence of Toxoplasma gondii isolates from animals and humans in China.
abstract: BACKGROUND
  Recent 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.
  
  
  RESULTS
  Genotyping 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).
  
  
  CONCLUSIONS
  A 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.
authors: Department of Parasitology, Provincial Laboratory of Microbiology & Parasitology, Anhui Medical University, Hefei, Anhui, China.
authors: Lin
authors: L
authors: Wang
authors: He
authors: H
authors: Chen
authors: Daohua
authors: D
authors: Liu
authors: Xingxing
authors: X
authors: Huo
authors: Jiangmei
authors: J
authors: Gao
authors: Xiaorong
authors: X
authors: Song
authors: Xiucai
authors: X
authors: Xu
authors: Kaiquan
authors: K
authors: Huang
authors: Wenqi
authors: W
authors: Liu
authors: Yong
authors: Y
authors: Wang
authors: Fangli
authors: F
authors: Lu
authors: Zhao-Rong
authors: ZR
authors: Lun
authors: Qingli
authors: Q
authors: Luo
authors: Xuelong
authors: X
authors: Wang
authors: Jilong
authors: J
authors: Shen
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D002415:Cats; D002681:China / Q000453:epidemiology; D016054:DNA, Protozoan / Q000145:classification / Q000235:genetics*; D005819:Genetic Markers; D014644:Genetic Variation; D005838:Genotype; D060005:Genotyping Techniques; D006801:Humans; D051379:Mice / Q000469:parasitology*; D008875:Middle Aged; D010802:Phylogeny; D058974:Phylogeography; D012150:Polymorphism, Restriction Fragment Length; D013552:Swine; D014122:Toxoplasma / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D014124:Toxoplasmosis, Animal / Q000469:parasitology*; D014126:Toxoplasmosis, Ocular / Q000453:epidemiology / Q000469:parasitology; D014774:Virulence
chemical_list: D016054:DNA, Protozoan; D005819:Genetic Markers