[Biological characteristics of the Korean isolate KI-1 of Toxoplasma gondii].
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.
Lin
Ai-fen
AF
Laboratory Center, Wenzhou Medical College Affiliated Taizhou Hospital, Linhai 317000, China. aifenlin@yaoo.com
Shin
Eun-hee
EH
Park
Jae-hwan
JH
Han
Eun-taek
ET
Chai
Jong-yil
JY
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*
D000953:Antigens, Protozoan; D016054:DNA, Protozoan