title: [Biological characteristics of the Korean isolate KI-1 of Toxoplasma gondii].
abstract: OBJECTIVE
  To study the biological characteristics of newly isolated Toxoplasma gondii Korean isolate-1 (KI-1).
  
  
  METHODS
  The morphology and infectivity of KI-1 were observed by transmission electron microscopy and animal inoculation. Both RH and KI-1 antigens were detected by an anti-T. gondii monoclonal antibody (mAb), Tg563, and an anti-Neospora caninum mAb, 12B4. The genotype was determined by PCR-RFLP analysis of SAG2 locus. The sequence heterogeneity of the SAG1, ROP1 gene coding regions of the RH and KI-1 was detected by an automated sequencer.
  
  
  RESULTS
  The morphology and infectivity of KI-1 were similar to those of RH strain. Both RH and KI-1 antigens reacted with Tg563, not with 12B4. In comparison to RH strain, the KI-1 showed a difference of seven positions of nucleotide substitutions and six positions of amino acid substitutions in both SAG1 and ROP1 gene coding regions.
  
  
  CONCLUSIONS
  KI-1 is an isolate of T. gondii with strong virulence. Compared with RH strain, certain genetic differences exist.
authors.affiliation: Laboratory Center, Wenzhou Medical College Affiliated Taizhou Hospital, Linhai 317000, China. aifenlin@yaoo.com
authors.forename: Ai-fen
authors.initials: AF
authors.lastname: Lin
authors.forename: Eun-hee
authors.initials: EH
authors.lastname: Shin
authors.forename: Jae-hwan
authors.initials: JH
authors.lastname: Park
authors.forename: Eun-taek
authors.initials: ET
authors.lastname: Han
authors.forename: Jong-yil
authors.initials: JY
authors.lastname: Chai
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000302:isolation & purification; D015153:Blotting, Western; D016054:DNA, Protozoan / Q000302:isolation & purification; D007723:Korea; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL / Q000469:parasitology*; D016133:Polymerase Chain Reaction; D011897:Random Allocation; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*
chemical_list: D000953:Antigens, Protozoan; D016054:DNA, Protozoan