Characterization of Toxoplasma gondii isolates from herds of sheep in southern Brazil reveals the archetypal type II genotype and new non-archetypal genotypes.

Recent studies have demonstrated that, in Brazil and South America, strains of Toxoplasma gondii are often genotypically and biologically different from those found in countries on other continents. The objective of this study was to genotypically characterize T. gondii isolates from naturally infected sheep in herds in the southern region of the state of Rio Grande do Sul, Brazil, by means of the polymerase chain reaction with restriction fragment length polymorphism (PCR-RFLP). Five T. gondii isolates obtained from sheep in five municipalities in the state of Rio Grande do Sul were used. Application of multilocus PCR-RFLP multilocus using 12 genetic markers (SAG1, 5'3' SAG2, alt. SAG2, SAG3, BTUB, c22-8, c29-2, GRA6, L358, PK1, APICO and CS3) revealed four different genotypes in the five isolates studied: clonal type II (TgOvBrRS4), type BrIV (TgOvBrRS2 and TgOvBrRS3) and two new non-archetypal genotypes, ToxoDB-RFLP#270 and #271 (TgOvBrRS1 and TgOvBrRS5, respectively). The genotype structure found in the T. gondii isolates from naturally infected sheep in the southern region of Brazil was revealed to have high diversity. This study confirms the presence of rare circulation of the clonal type II genotype in Brazil.

First report of typical Brazilian Toxoplasma gondii genotypes from isolates of free-range chickens (Gallus gallus domesticus) circulating in the state of Paraíba, Northeast Brazil.

This study evaluated, for the first time, the genetic diversity of Toxoplasma gondii isolates from free-range chickens from the state of Paraíba, Northeast Brazil. Tissue samples from 33 chickens from properties in five municipalities of Paraíba (Esperança, Olho d'Água, Malta, Monteiro, and Patos) were bioassayed in mice. The brains of mice infected with T. gondii cysts were used for DNA extraction and genotyping. Genotyping was performed using 11 PCR-RFLP markers and 15 microsatellite (MS) markers. Complete genotyping results were obtained for 29 isolates, with nine genotypes detected by RFLP and 15 genotypes identified by MS. Three genotypes (#273, #274, and #277) have only been recently identified from pigs in the region. Brazilian clonal types BrII and BrIII were identified from one isolate each. Clonal types I, II, and III were not detected by RFLP. Genotype #13 (Caribbean 1), detected in 48.3% (14/29) of isolates from four of the five municipalities investigated, was the most prevalent genotype in the state of Paraíba. However, the MS analysis showed that of these 14 isolates, only four were unique genotypes, and considering the distance between the municipalities from where they were collected, it is possible that only seven are independent isolates while the others are clones. The other genotypes were restricted to different microregions. The results indicate that the Caribbean 1 lineage of T. gondii is circulating widely in Northeast Brazil. The genotypic diversity of T. gondii in the state of Paraíba is high, and microsatellite analysis revealed this diversity with higher resolution than PCR-RFLP.

First study on seroepidemiology and isolation of Toxoplasma gondii in free-range chickens in the semi-arid region of Paraíba state, Brazil.

The aim of this study was to investigate the seroprevalence and isolation of Toxoplasma gondii in free-range chickens in the state of Paraíba, northeastern Brazil. For this, blood samples were collected from 483 chickens in five municipalities in the state of Paraíba. The indirect immunofluorescence assay for anti-T. gondii antibodies was performed. The seropositive birds were slaughtered, and their brains and hearts were collected in order to perform a bioassay in mice. An epidemiological questionnaire was applied on the smallholdings visited, and univariable and multivariable logistic regressions were used to evaluate risk factors. The prevalence of chickens seropositive for T. gondii was found to be 31.5 % (152/483), and 86.1 % (56/65) of the smallholdings were positive. Among the 71 chickens subjected to bioassaying in mice, isolates of T. gondii were obtained from 33 (46.5 %). The isolates were named TgCkBrPB1 to 33. It was observed that the higher the chickens' antibody titer was, the greater the chance of isolating the parasite also was. Sixteen of the 33 isolates (48.5 %) were lethal for all the mice inoculated until 30 days post-inoculation. The risk factors for infection with T. gondii among these free-range chickens were extensive and semi-extensive rearing systems, smallholdings located in urban areas, and presence of cats. The results indicate that the prevalence of T. gondii among chickens in the state of Paraíba is high. Many parasites remained viable in the tissues of the birds studied, and presence of the protozoan was directly related to the management of these birds.

Genotyping of Toxoplasma gondii isolates from free range chickens in the Pantanal area of Brazil.

The aim of this paper was to genetically characterize Toxoplasma gondii isolates from free range chickens in regions of Brazilian territory in the state of Mato Grosso do Sul (MS) where T. gondii strains have never been studied. In total, T. gondii isolates from 22 free range chickens were included in this study. Fifty chickens from Eldorado, thirty from Rio Verde and ten from Aquidauana were sampled between January and April 2007. In relation to the genetic diversity of T. gondii isolates from chickens in MS, the magnitude of the diversity in the isolates sampled in this study was comparable to the overall diversity in a composite data set. These 22 isolates in MS revealed 11 genotypes, whereas the 321 isolates ever genotyped in Brazil have revealed 95 genotypes. The values of Simpson's Diversity Index for the whole population of T. gondii isolates in Brazil, the whole population of T. gondii isolates from chickens in Brazil and the population surveyed in this study were 0.97, 0.95 and 0.90, respectively. Seven of the 11 genotypes revealed from chicken isolates from MS are newly described genotypes and six of them each have a single isolate. In conclusion, the results obtained from isolates in MS corroborate previous studies on T. gondii isolates in Brazil, thus confirming their diversity and atypicality. Nonetheless, the applicability of PCR-RFLP markers for epidemiological inferences remains controversial.