Cat-rodent Toxoplasma gondii Type II-variant circulation and limited genetic diversity on the Island of Fernando de Noronha, Brazil

Research on the UNESCO-listed Fernando de Noronha Island reveals limited genetic diversity of Toxoplasma gondii, with strains primarily clustering into Type II, III, and Caribbean 1 groups. Unlike mainland Brazil, where T. gondii strains show high pathogenicity to mice and genetic variability, isolates from Fernando de Noronha—derived from cats and rodents—were non-pathogenic to outbred mice. Genetic analysis suggests recent introduction of a few founding strains, likely via imported cats, with minimal evidence of mainland-derived strain transmission. The study used 11 PCR-RFLP and 15 microsatellite markers to characterize isolates, highlighting the island's unique epidemiological profile.

Silva, J. C. R., Ferreira, F., Dias, R. A., Ajzenberg, D., Marvulo, M. F. V., Magalhães, F. J. R., Filho, C. D. F. L., Oliveira, S., Soares, H. S., Feitosa, T. F., Aizawa, J., Alves, L. C., Mota, R. A., Dubey, J. P., Gennari, S. M., & Pena, H. F. J. (2017). Cat-rodent Toxoplasma gondii Type II-variant circulation and limited genetic diversity on the Island of Fernando de Noronha, Brazil. Parasites & Vectors, 10(1). https://doi.org/10.1186/s13071-017-2150-4