Toxoplasma gondii is a parasite with high importance to animal production and public health, involving fetal alterations and abortions in humans and animals, being an important opportunistic pathogen in immunocompromised patients too. It has a populational structure with predominant lineages type I, II and III. The transmission of the parasite by food has been characterized as high risk to the human health. The world consumption and commercialization of meat products from ostriches have shown high increase, but with low studies related to toxoplasmosis, representing a potential risk of infection by food for man. In this way, soil and cat feces will be collected three times per year, in one year, in the commercial farms that supply animals to the slaughter in the slaughterhouses from Laranjal Paulista e Boituva-SP. In the slaugherhouses, blood, brain, diaphragm and heart samples of the same ostriches will be collected. After to obtain the sera samples, the sera samples will be submitted to serological tests, as modified agglutination test, with methanol-fixed (MAT-AF) or formalin-fixed antigen (MAT-AM), to differentiate the stages of Toxoplasma infection, and to indirect fluorescent antibody test (RIFI) to research IgM and IgG. Tissue samples from seropositive animals will be macerated and digested by pepsin action, and bioassayed in mice for the isolation of the parasite. The research of oocysts in the soil will be performed by centrifuge-flutuation method in Sheater's sugar fluctuation solution. Genotyping of the samples isolated from ostriches, cat feces and soil will be performed by multiplex-PCR, nested-PCR and the restriction fragment length polymorphism (RFLP-PCR) in 12 loci (SAG1, 5'-3'SAG2, aSAG2, SAG3, BTUb, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3), besides the association of the virulence obtained in bioassay with the profiles obtained in ROPD18Del and ROP18UPS markers. The results of the genotyping will be analyzed by the determination of the phylogeny in the SplitsTree program. Thus, this study is aimed to isolate T.gondii of tissues from ostriches slaughtered for human consumption, and in soil and cat feces from commercial farms; to detect the stage of the infection at the moment of the slaughter by the comparison of serological tests; to compare the genotyping profiles obtained in RFLP-PCR for 12 genetic markers and perform the phylogenetic analysis of the isolates to determine the phylogenetic relationship among these.
News published in Agência FAPESP Newsletter about the scholarship: