Regiane Trigueiro Vicente

The IFN-³+874T/A gene polymorphism is associated with retinochoroiditis toxoplasmosis susceptibility

Toxoplasmosis is a worldwide zoonosis that generally produces an asymptomatic infection. In some cases, however, toxoplasmosis infection can lead to ocular damage. The immune system has a crucial role in both the course of the infection and in the evolution of toxoplasmosis disease. In particular, IFN-gamma plays an important role in resistance to toxoplasmosis. Polymorphisms in genes encoding cytokines have been shown to have an association with susceptibility to parasitic diseases. The aim of this work was to analyse the occurrence of polymorphisms in the gene encoding IFN-gamma (+874T/A) among Toxoplasma gondii seropositive individuals, including those with ocular lesions caused by the parasite, from a rural population of Santa Rita de Cássia, Barra Mansa, state of Rio de Janeiro, Brazil. Further, we verified which of these polymorphisms could be related to susceptibility to the development of ocular toxoplasmosis. This study included 34 individuals with ocular toxoplasmosis (ocular group) and 134 without ocular lesions (control group). The differences between A and T allele distributions were not statistically significant between the two groups. However, we observed that a higher frequency of individuals from the ocular group possessed the A/A genotype, when compared with the control group, suggesting that homozygocity for the A allele could enhance susceptibility to ocular toxoplasmosis in T. gondii infection.

Soroprevalência de anticorpos anti-Toxoplasma gondii em bovinos e funcionários de matadouros da microrregião de Pato Branco, Paraná, Brasil

In order to determine the role of bovine meat in the epidemiology of toxoplasmosis, 348 serum samples were collected from cattle and 64 serum samples from slaughterhouse workers at four plants in the region of Pato Branco, Parana state, southern Brazil. Cattle sera were examined by the indirect fluorescent antibody test (IFAT), showing an IgG-seropositivity of 41.4%. The most frequently titer found was 64 (92.4%). Maximum titer found was 1024. There was no significant difference concerning sex, age and origin of positive sera. Human sera were tested by the IFAT and enzyme-linked immunosorbent assay (ELISA), showing 67.2% and 84.4% of IgG-seropositivity, respectively. No significant difference was observed between prevalences and age, sex, duration of employment at slaughterhouse, contact with cats and eating raw or undercooked meat. Results suggest that bovine meat may be a possible source of toxoplasmosis in the region.

Toxoplasma gondii: estudo soro-epidemiológico de suínos da região Sudoeste do Estado do Paraná

This study evaluated the seroprevalence of toxoplasmosis in pigs bred and slaughtered for human consumption. The frequency of the antibody anti-Toxoplasma gondii was investigated in 408 animals from distinct piggeries of 25 cities in the southwestern region of the state of Parana, Brazil. Serum samples were examined for IgG antibodies specific for T. gondii through the indirect fluorescent antibody test (IFAT). A frequency of 25.5% of serum samples tested positive for dilutions equal to or greater than 1:64. Statistically significant were not observed in relation to sex and age of the animals. The highest antibody level observed was 4,096 (3.0%) and the most frequent was 64 (74%), suggesting that a chronic infection occurred in the population. The high prevalence of the infection found in the swine herds of this region suggests that these herds can be a source of infection for individuals who typically consume this type of raw or badly cooked meat.

Occurrence of infection with Toxoplasma gondii and factors associated with transmission in broiler chickens and laying hens in different raising systems

Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii. The aim of the present study was to determine the occurrence and identify the risk factors associated with transmission of T. gondii to chickens raised in different systems (free-ranged and conined) to produce eggs or meat. The 810 animals were allocated in two experimental groups according to the production system purpose: 460 broiler chickens (Group 1) and 350 layer chickens (Group 2). In order to analyze the possible factors involved in T. gondii infection in the chickens, an epidemiological questionnaire was developed for all properties.The serological detection of anti-Toxoplasma gondii antibodies was performed by Indirect Immunoluorescence (IFAT) and by Enzime Linked Imunossorbent Assay (ELISA). Since the agreement index (kappa) between these two serological techniques was considered high, 21.2% of the 810 animals were considered reactive. In Group 1, 12.2% (56/460) were positive, while in the Group 2 the positivity rate was 33.1% (116/350). The production system may be inluencing the seropositivity of the animals in both groups. However, only in Group 2 it was possible to notice a statistically signiicant relationship between the breeding system and the frequency of positive sera. This result indicates that, at least for laying hens, the production system is directly involved in T. gondii infection. The contact with cats in Group 1 did not inluence the distribution of seroreactive animals, but in Group 2 a signiicant relationship was observed. The occurrence of anti-T. gondii antibodies was high in both groups (broiler and posture chickens). Free-ranged chickens raised for egg production proved to be the most exposed group to the T. gondii infection. This can be related to the fact that these animals stay for longer periods in the farms, in direct contact with possibly contaminated soil by the presence of domestic cats. INDE.

Toxoplasmosis in squirrel monkeys: histological and immunohistochemical analysis

Necropsy findings in three cases of naturally occurring toxoplasmosis in squirrel monkeys (Saimiri sciureus) obtained as wild catches from the Amazon region were described. Histopathological evaluation of the liver, spleen, kidneys and mesenteric lymph nodes showed multiple foci of inflammation and necrosis. Typical, well-defined morphologic Toxoplasma gondii cysts and free forms of the parasite were found by immunoperoxidase staining within inflammatory infiltrates. The presence of T. gondii in the studied colony could severely influence the results of experiments performed in the animals.

Seroprevalence of Toxoplasma gondii infection in swine matrices in Nova Mutum and Diamantino, Mato Grosso, Brazil

This report aimed to assess the seroprevalence of Toxoplasma gondii infection in 708 swine matrices in Nova Mutum and Diamantino in the state of Mato Grosso, Central-West Brazil. Serum samples were examined by indirect fluorescent antibody test (IFAT). It was found a seroprevalence of 12.8%, considering titers ≥ 64. Therefore, the data reinforce the need for appropriate management of swine raising to minimize the risk of infection of pigs with T. gondii.