Sunday, June 29, 2008

Genotyping studies of Toxo isolates from Africa revealed that the archetypal clonal lineages predominate as in North America and Europe

Vet Parasitol. 2008 May 10. [Epub ahead of print]

Genotyping studies of Toxoplasma gondii isolates from Africa revealed that the archetypal clonal lineages predominate as in North America and Europe

Velmurugan GV, Dubey JP, Su C.

United States Department of Agriculture, Agricultural Research Service, Animal and Natural Resources Institute, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, MD 20705-2350, USA.

Until recently, Toxoplasma gondii was considered to be clonal with very little genetic variability. Recent studies indicate that T. gondii isolates from Brazil are genetically and biologically different from T. gondii isolates from USA and Europe. However, little is known of the genetics of T. gondii strains from Africa. In this study, we genotyped 19 T. gondii isolates from chickens from six African countries (Egypt, Kenya, Nigeria, Congo, Mali, and Burkina Fasco) using 10 PCR-RFLP markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The results revealed four genotypes. Thirteen isolates belong to the Type III lineage, five isolates have Type II alleles at all loci except apico and they belong to the Type II lineage. One isolate from Nigeria had atypical genotype. In general, these isolates were mostly clonal Type III and II strains that predominate in North American and European. DNA sequencing at several loci for representative isolates confirmed the results of PCR-RFLP genotyping. Taken together with recent studies of T. gondii isolates from Africa, it is clear that the three clonal lineages (Types I, II and III) predominate not only in North America and Europe, but also in Africa.

PMID: 18583059 [PubMed - as supplied by publisher]

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