K24 T. gondii isolate is a hybrid and has the virulence of lineage I isolates.
A permanently high virulence was found in tachyzoites of T. gondii K24 after serial passage in mice (90 passages during 324 days). Virulence tests revealed that a single tachyzoite of the 50th passage represented LD100 for mice. Analysis of genotype of K24 isolate was done by PCR/RFLP with ROP1/Ddel, SAG1/Ddel, 850/Rsal and IGS/Rsal and by RFLP/DNA with TGR1E sequence and Pstl enzyme. K24 isolate had an atypical genotype, with an association of type II (for ROP1, SAG1 genes and TGR1E sequence) and type I (for 850 gene) alleles, and a new pattern observed for IGS. All tested PCR/RFLP did not change through 2, 10, 20, 28, 40, 50, 60, 70, 81 and 90 tested passages. In RFLP/DNA with Pstl enzyme and TGR1E probe, K24 isolate produced a pattern with seven fragments of the size ranging from one to 23 kb and did not change through 7, 56, 70 and 83 tested passages. K24 T. gondii isolate is a hybrid and has the virulence of lineage I isolates.
Bártová
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Department of Biology and Wildlife Diseases, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic. bartovae@vfu.cz
Literák
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D000818:Animals; D016054:DNA, Protozoan / Q000032:analysis*; D005838:Genotype; D007928:Lethal Dose 50; D051379:Mice; D008970:Molecular Weight; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D015800:Protozoan Proteins / Q000235:genetics*; D011897:Random Allocation; D012692:Serial Passage; D014122:Toxoplasma / Q000235:genetics* / Q000472:pathogenicity*; D014124:Toxoplasmosis, Animal / Q000469:parasitology*; D014774:Virulence / Q000235:genetics
D016054:DNA, Protozoan; D015800:Protozoan Proteins