Rare case of acute toxoplasmosis in a domestic rabbit (Oryctolagus cuniculus) in Brazil associated with the type BrIII Brazilian clonal lineage of Toxoplasma gondii.

Toxoplasmosis is a widely distributed disease that infects birds and mammals, including humans. Acute clinical course of toxoplasmosis is considered to be rare among domestic rabbits (Oryctolagus cuniculus). The aim of this study was to present the first report of fatal acute disease caused by Toxoplasma gondii type BrIII genotype, a typical Brazilian clonal lineage, in a domestic rabbit. T. gondii was identified in histological sections of spleen and liver tissue, and these tissues were also immunohistochemically positive for T. gondii. After the histopathological and immunohistochemical confirmation of T. gondii, the genotype of this pathogen was determined via PCR-RFLP with 11 markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, and CS3) and via microsatellite (MS) analysis with 15 markers (TUB2, W35, TgMA, B18, B17, M33, IV.1, X1.1, M48, M102, N60, N82, AA, N61, and N83). This study shows that type BrIII genotype, circulating in Brazil in different hosts, can cause acute disease in a naturally infected animal host. The described case also involves the first reported occurrence of the 291 allele for the typing marker TUB2 in a type BrIII strain, emphasizing the genetic diversity of T. gondii in Brazil.