Genetic Characterization of Toxoplasma gondii Revealed Highly Diverse Genotypes for Isolates from Newborns with Congenital Toxoplasmosis in Southeastern Brazil

Abstract

e Recent studies of Toxoplasma gondii isolates from animals in Brazil have revealed high genetic diversity. Many of these isolates are virulent to mice. It is speculated that these isolates may also be virulent to humans. However, there is very limited data regarding T. gondii strains from human infection. Therefore, it is not clear whether there is any association between parasite genotypes and disease phenotypes. In this study, a total of 27 T. gondii strains were isolated from humans with congenital toxoplasmosis in Minas Gerais state, Brazil. The genetic variability was assessed by restricted fragment length polymorphism in 11 loci (SAG1, 5= plus 3= SAG2, alternative [alt.] SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Genetic analysis of 24 strains revealed 14 different genotypes, including 7 previously identified from animals and 7 new types. The widespread genotype BrII accounted for 29% (7/24) of the isolates and was the dominant genotype involved in this study. This is the first report of genotyping of T. gondii isolates obtained from blood samples from newborns with congenital toxoplasmosis. Genotypic characterization of these isolates suggests high genetic diversity of T. gondii in this human population in Brazil. Future studies are needed to determine the source of contamination of this human population.

Adaptive and genetic evolution of Toxoplasma gondii: a host-parasite interaction

“…The observations documented by the author concerning the clinical manifestations in humans, has been reported not just in Rio Grande do Norte, but also in newborns 1 and AIDS patients 2,3 from Minas Gerais and Sao Paulo, and many other places in South America, indicating a high genetic diversity that includes atypical genotypes. In veterinary medicine, many different genotypic profiles have also been reported in a wide range of domestic and wild intermediate hosts, some of which are considered sources of infection for humans, and others, just sentinels 1,4-6 .…”

“…Rodrigo Costa da Silva [1] , Helio Langoni [2] and Jane Megid [2] [1]. Setor de Veterinária e Produção Animal, Centro de Ciências Agrárias, Universidade Estadual do Norte do Paraná, Bandeirantes, PR, Brasil.…”

An atypical Toxoplasma gondii genotype in a rural Brazilian dog co-infected with Leishmania (Viannia) braziliensis

“…In the same way, samples positive for T. gondii were also typed by RFLP-PCR using 11 markers for genotype identifi cation (10) . All three tissue samples were confi rmed to contain T. gondii by genotyping, and demonstrated an atypical genotype (Table 3) reported in the scientifi c literature to cause human congenital toxoplasmosis, TgCTBr5 (4) . All amplifi cations were performed in a MasterCycler ep gradient (Eppendorf, USA).…”

“…Felids are the defi nitive hosts, while most warm-blooded animals are intermediate hosts (1) . Dogs are considered sentinels for human infection; they are infected by ingesting raw or poorly cooked meat containing tissue cysts and by ingesting sporulated oocysts present in the contaminated feces of cats (2) (3) (4) .…”

Análise do controle da toxoplasmose gestacional e ocular nos serviços de atenção primária da 15ªRegional de Saúde do Paraná

“…Este protozoário pode atravessar a placenta e causar morte intrauterina, retardamento mental, coriorretinite, cegueira, meses ou anos após o nascimento 2 . O desfecho da transmissão congênita é influenciado por fatores tais como cepa, virulência e genótipo do T. gondii, tamanho do inóculo, tempo de duração na gestação, estado imune da gestante, parasitemia materna, idade gestacional no momento da infecção e tratamento quimioterápico 3,4,5 .…”