Techniques of genotyping for molecular epidemiology and population study of Toxoplasma gondii

• Grant number: 19/05581-8
• Support type: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): January 15, 2020
• Effective date (End): December 30, 2020
• Field of knowledge: Biological Sciences - Immunology - Immunogenetics
• Principal researcher: Luiz Carlos de Mattos
• Grantee: Geraldo Magela de Faria Junior
• Supervisor abroad: Chunlei Su
• Home Institution: Faculdade de Medicina de São José do Rio Preto (FAMERP). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). São José do Rio Preto , SP, Brazil
• Research place: University of Tennessee (UT), United States
• Associated to the scholarship: 18/09448-8 - Expression of miRNAs in ocular Toxoplasmosis, BP.DR

Abstract

Toxoplasma gondii is an obligate intracellular protozoan with a worldwide distribution, affecting all warm-blooded animals and humans. One-third of the human population is assumed to be infected with T. gondii and this infection may result in various morbidities in humans and animals, as ocular, congenital, cerebral toxoplasmosis, abortion, and fetal death.The number and genetic diversity of this parasite play an important role in pathogenesis of T. gondii infection. Identifying the genotypes of T. gondii using molecular techniques is invaluable in epidemiological studies. These techniques include multilocus polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP), microsatellite analysis, random amplified polymorphic (RAPD), multilocus sequence typing (MLST) and high-resolution melting (HRM). The first studies in genotyping of T. gondii strains in France and in the United States of America demonstrated a clonal population structure with three main lineages, type I, II and III. Studies showed that in Brazil, a wide diversity of strains of T. gondii are presented, and the aspects related to the infection between host and pathogen is still not clear for these strains this way, more research are needed to understand the infection of T. gondii in Brazil. In the current PhD proposal, I will check the expression of microRNAs (miR 712-3p, miR 511-5p, miR 217-5p and miR-9-2) in the plasma of patients with ocular toxoplasmosis. As these microRNAs were detected in T. gondii infected animal models and the authors verified that they had a high plasma concentration, our hypothesis is that they may be associated with the occurrence of ocular disease resulting from T. gondii infection, these way, I will investigate the immunological behavior of the host in the susceptibility and resistance of T. gondii infection, and also the understanding of the development of the ocular disease caused by this parasite. Therefore, the identification of the types of T. gondii strains and the understanding of the interaction between host and parasite will contribute to the knowledge of the pathophysiology of the disease.