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Toxoplasma gondii infection can cause abortions or congenital infection for a vast number of domestic animals and humans, leading to economic loss in veterinary sciences, as well as severe consequences for immunocompromised patients. Bidens pilosa Linné has been used in ethnopharmacology for treatment of diseases, as malaria, diabetes and hepatitis, in addition to its use as antioxidant, antiallergic, anti-inflammatory, and antiviral. The components of this plant have never been studied before for treatment of toxoplasmosis, and the conventional drugs currently used to treat this disease have high degree of toxicity. Thus, the aim of this study was to evaluate the effect of B. pilosa against T. gondii, by analyzing a total extract of this plant in parallel with a fraction obtained by precipitation in acetone. Also, it was assessed if the acetonic fraction could present lectinic activity, followed by its identification by mass spectrometry. It was observed with the experimental models designed that both total extract and acetonic fraction of B. pilosa were able to control T. gondii infection by in vitro and in vivo experiments, in addition to their low toxicity to host cells. Both total extract and acetonic fraction of this plant display capacity to impair replication of T. gondii tachyzoites. Interesting, the B. pilosa acetonic fraction treatment for 10 days after infection decreases significantly the number of T. gondii brain cyst in comparison with controls. The protein isolated from B. pilosa acetonic fraction was characterized as a novel lectin identified as maturase K. Taken together, these findings open new perspectives to treat patients infected by T. gondii. Future studies will be necessary to investigate the precise mechanism underlying the control of T. gondii infection to impair the replication of this parasite in the host cells after treatment with B. pilosa maturase K.

Hymenoptera venoms constitute an interesting source of natural toxins that may lead to the development of novel therapeutic agents. The present study investigated the enzymatic and biological characteristics of the crude venom of the ant Odontomachus bauri. Its crude venom presents several protein bands, with higher staining for six proteins with gelatinolytic activity (17, 20, 26, 29, 43 and 48 kDa). The crude venom showed high proteolytic activity on azocasein at optimal pH 8.0 and 37 °C. In the presence of protease inhibitors as aprotinin, leupeptin and EDTA, the azocaseinolytic activity was reduced by 45%, 29% and 9%, respectively, suggesting that the enzymes present in the crude venom belong to the three classes of proteases, with the serine proteases in greater intensity. The crude venom degraded the fibrinogen α-chain faster than the β-chain, while the fibrinogen γ-chain remained unchanged. In biological assays, O. bauri venom showed hemolytic and coagulant activity in vitro, and defibrinating activity in vivo. In addition, the venom showed antimicrobial activity against Staphylococcus aureus and Escherichia coli as well as antiparasitic activity on Toxoplasma gondii infection in vitro. In that sense, this study sheds perspectives for pharmacological applications of O. bauri venom enzymes.

Considerando a importância da neosporose interferindo na produtividade animal, avaliou-se a frequência de anticorpos anti-Neospora caninum em amostras de soros de bovinos leiteiros da Região Sudoeste do Estado de Mato Grosso, Brasil, complementando-se com amostras sorológicas colhidas de cães e de humanos que conviviam nas mesmas propriedades rurais amostradas. Um total de 1.036 amostras de soros foram analisadas, sendo 932 de fêmeas bovinas leiteiras, 37 de cães e 67 de humanos, provenientes de 24 propriedades e examinados por meio da reação de imunofluorescência indireta (RIFI). As amostras de soros humanos reagentes foram testadas novamente por Western-blotting para confirmação dos resultados. Anticorpos anti-N. caninum foram encontrados em 499 bovinos (53,5%), em pelo menos um animal positivo por propriedade, em 25 caninos (67,6%) e em sete humanos (10,5%). Não houve diferença significativa no número de bovinos positivos por faixa etária. Os resultados obtidos indicam uma ampla disseminação de N. caninum na região estudada.Considering the importance of neosporosis in the animal health and production, the frequency of antibodies to Neospora caninum was evaluated in dairy cattle of the Southwestern region of Mato Grosso State, Brazil, in addition to serum samples obtained from dogs and humans living in the farms. A total of 1036 serum samples were analyzed, from which 932 were from dairy bovine females, 37 from dogs and 67 from humans, from 24 farms and examined by the indirect fluorescent antibody test (IFAT). Reactive human serum samples were retested by Western-blotting to confirm the results. Antibodies to N. caninum were found in 499 cattle sera (53.5 %), with at least one positive in each farm, 25 dog sera (67.6 %) and seven human sera (10.5 %). There was no significant difference in the number of positive cattle sera according to age group. The results indicate a wide dissemination of N. caninum in the studied region.

IgE antibody response in human strongyloidiasis was evaluated by enzyme-linked immunosorbent assay (ELISA) and immunoblotting (IB) using Strongyloides ratti saline extract as heterologous antigen. A total of 50 serum samples of patients who were shedding S. stercoralis larvae in feces (group I, copropositive), 38 of patients with other intestinal parasites (group II), and 38 of subjects with negative results in three parasitologic assays (group III, copronegative) were analyzed. Levels of IgE anti-Strongyloides expressed in ELISA Index (EI) were significantly higher in patients of group I (1.32) than in group II (0.51) and group III (0.81), with positivity rates of 54%, 0%, and 10.5%, respectively. Fifteen S. ratti antigenic components were recognized in IB-IgE by sera of group I, with frequency ranging from 8% to 46%. In group II, only two antigenic bands (101, 81 kDa) were detected in a frequency of 10% and no reactivity was found in group III. Sera with EI values > 1.5 recognized five from 13 specific antigenic bands (70, 63, 61, 44, 7 kDa). It can be concluded that these five antigenic components recognized by IB-IgE using S. ratti antigen might be employed as an additional tool for improving the immunodiagnosis in human strongyloidiasis.

Strongyloides ratti larval extract was used for the standardization of ELISA to detect genus-specific IgE in human strongyloidiasis. Forty serum samples from monoinfected patients shedding S. stercoralis larvae (Group I), 40 from patients with other intestinal parasites (Group II), and 40 from copronegative healthy subjects (Group III) were analyzed. Genus-specific IgE levels (ELISA Index: EI) were significantly higher in the group I (EI = 1.43) than groups II (EI = 0.70) and III (EI = 0.71), showing positivity rates of 55%, 2.5% and 0%, respectively. Similarly, sera from copropositive patients had significantly higher levels of total IgE (866 IU/mL) as compared to those from group II (302 IU/mL) and III (143 IU/mL). A significant positive correlation was found between levels of Strongyloides specific-IgE and total IgE in sera from patients with strongyloidiasis. In conclusion, S. ratti heterologous extract showed to be a useful tool for detecting genus-specific IgE by ELISA, contributing for a better characterization of the immune response profile in human strongyloidiasis.Extrato contendo larvas de Strongyloides ratti foi usado na padronização de um ELISA para detecção de IgE gênero-específica na estrongiloidíase humana. Foram analisadas 40 amostras de soro de pacientes monoinfectados que estavam eliminando larvas de S. stercoralis nas fezes (Grupo I), 40 de pacientes com outros parasitos intestinais (Grupo II), e 40 indivíduos copronegativos (Grupo III). Níveis de IgE gênero-específica (índice ELISA: EI) foram significativamente maiores no Grupo I (EI = 1,43) do que no II (EI = 0,70) e III (EI = 0,71), mostrando positividade de 55%, 2,5% e 0%, respectivamente. Similarmente, soros dos pacientes copropositivos (Grupo I) apresentaram níveis significativamente maiores de IgE total (866 IU/mL) quando comparados com os soros dos Grupo II (302 IU/mL) e III (143 IU/mL). Uma significativa correlação positiva foi encontrada entre os níveis de IgE específica a Strongyloides sp. e IgE total nos soros de pacientes com estrongiloidíase. Em conclusão, extrato heterólogo de S. ratti mostrou ser uma ferramenta útil para detecção de IgE gênero-específica por ELISA, desta forma contribuindo para melhor caracterização do perfil da resposta imune na estrongiloidíase humana.