Objective: The present study aimed to evaluate the presence of helminthes and intestinal protozoa... more Objective: The present study aimed to evaluate the presence of helminthes and intestinal protozoa in vegetables commercialized in Diamantina, a municipality located at Jequitinhonha Valley, one of the poorest regions of the world. Methods: A total of 108 specimens, including lettuce, green onion and rocket, were monthly collected from the most popular open street market, green grocery and supermarket of the municipality. The samples were processed by a concentration method and evaluated by light microscopy for parasitological identification. Results: The percentage of contamination was 50.9% (55/108), with predominance of nematode larvae (36.5%), cysts of Entamoeba coli (26.0%) and eggs of hookworms/Strongyloides spp. (12.9%). Lettuce showed greater contamination rate (61.1%) and samples from the open street market were more contaminated (77.8%). Information collected at each point of sale pointed the field cultivation as the critical step for such contaminations. Conclusion: Vegeta...
Doencas alergicas e infeccoes produzidas por helmintos parasitos induzem uma resposta imune predo... more Doencas alergicas e infeccoes produzidas por helmintos parasitos induzem uma resposta imune predominantemente Th2, estimulando o aumento e ativacao de eosinofilos, basofilos, mastocitos e altos niveis de IgE circulantes. No caso da esquistossomose, a resposta Th2 e estimulada com o inicio da ovipostura e geralmente e acompanhada por aumento de IL-10, resultando em uma infeccao cronica modulada que persiste por anos. Alguns estudos epidemiologicos tem relatado associacoes inversas entre alergia e helmintoses, propondo que a exposicao frequente do sistema imune a agentes infecciosos pode levar ao desenvolvimento de uma resposta imune modulada, evitando, em parte, o desenvolvimento de doencas inflamatorias. Entretanto, a maioria dos trabalhos publicados tem sido realizados em areas com alta carga parasitaria, situacao que tem sido alterada em muitas areas endemicas brasileiras nos ultimos anos devido ao impacto dos programas de controle. Com o intuito de esclarecer alguns destes aspect...
Wild rodent species are naturally infected by Schistosoma mansoni; however, the genetic character... more Wild rodent species are naturally infected by Schistosoma mansoni; however, the genetic characterization of the parasite, its parasitological features, and its role in human schistosomiasis are poorly understood. In this study, we isolated and characterized Schistosoma from naturally infected Holochilus sciureus, called HS strain, collected from a schistosomiasis endemic region in Maranhão State, Brazil. To isolate the parasite, miracidia obtained from the livers of H. sciureus were used to infect Biomphalaria glabrata of sympatric (called SB) and allopatric (called BH) strains, and the produced cercariae were subcutaneously inoculated into hamsters and/or BALB/c mice. Parasitological kinetics in experimentally infected hosts were evaluated, and the 16S and cox 1 regions of mtDNA from isolated worms were amplified and sequenced. Only miracidia obtained from infected mice, but not from hamsters, were capable of infecting B. glabrata, allowing maintenance of the isolated parasite. Cox...
Schistosomiasis and Leishmaniasis are chronic parasitic diseases with high prevalence in some tro... more Schistosomiasis and Leishmaniasis are chronic parasitic diseases with high prevalence in some tropical regions and, due to their wide distribution, a risk of co-infections is present in some areas. Nevertheless, the impact of this interaction on human populations is still poorly understood. Thus, the current study evaluated the effect of previous American Tegumentary Leishmaniasis (ATL) on the susceptibility and immune response to Schistosoma mansoni infection in residents from a rural community in Northern of Minas Gerais state, Brazil, an area endemic for both parasitic infections. The participants answered a socioeconomic questionnaire and provided stool and blood samples for parasitological and immunological evaluations. Stool samples were examined by a combination of parasitological techniques to identify helminth infections, especially S. mansoni eggs. Blood samples were used for hemograms and to measure the serum levels of cytokines and chemokines. Reports on previous ATL wer...
The severity of chronic schistosomiasis has been mainly associated with the intensity and extensi... more The severity of chronic schistosomiasis has been mainly associated with the intensity and extension of the inflammatory response induced by egg-secreted antigens in the host tissue, especially in the liver and intestine. During acute schistosomiasis, eosinophils account for approximately 50% of the cells that compose the liver granulomas; however, the role of this cell-type in the pathology of schistosomiasis remains controversial. In the current study, we compared the parasite burden and liver immunopathological changes during experimental schistosomiasis in wild-type (WT) BALB/c mice and BALB/c mice selectively deficient for the differentiation of eosinophils (ΔdblGATA). Our data demonstrated that the absence of eosinophil differentiation did not alter the S. mansoni load or the liver retention of parasite eggs; however, there were significant changes in the liver immune response profile and tissue damage. S. mansoni infection in ΔdblGATA mice resulted in significantly lower liver concentrations of IL-5, IL-13, IL-33, IL-17, IL-10, and TGF-β and higher concentrations of IFN-γ and TNF-α, as compared to WT mice. The changes in liver immune response observed in infected ΔdblGATA mice were accompanied by lower collagen deposition, but higher liver damage and larger granulomas. Moreover, the absence of eosinophils resulted in a higher mortality rate in mice infected with a high parasite load. Therefore, the data indicated that eosinophils participate in the establishment and/or amplification of liver Th-2 and regulatory response induced by S. mansoni, which is necessary for the balance between liver damage and fibrosis, which in turn is essential for modulating disease severity.
The plasma level of the chemokine CCL3 is elevated in patients with chronic severe schistosomiasi... more The plasma level of the chemokine CCL3 is elevated in patients with chronic severe schistosomiasis mansoni. We have previously shown that CCL3 −/− mice with experimental infection showed diminished pathology and worm burden compared to those of wild-type (WT) mice. To elucidate further the role of CC chemokines during schistosomiasis mansoni infection, we evaluated the course of infection in C57BL/6J mice deficient in CCR5, one of the receptors for CCL3. The CCR5 deficiency proved to be remarkably deleterious to the host, since mortality rates reached 70% at 14 weeks postinfection in CCR5 −/− mice and 19% in WT mice. The increased lethality was not associated with an increased parasite burden, since similar numbers of eggs and adult worms were found in mice from both groups. Liver granulomas of chronically infected CCR5 −/− mice were larger and showed greater numbers of cells and collagen deposition than liver granulomas from WT mice. This was associated with higher levels of produc...
Objective: The present study aimed to evaluate the presence of helminthes and intestinal protozoa... more Objective: The present study aimed to evaluate the presence of helminthes and intestinal protozoa in vegetables commercialized in Diamantina, a municipality located at Jequitinhonha Valley, one of the poorest regions of the world. Methods: A total of 108 specimens, including lettuce, green onion and rocket, were monthly collected from the most popular open street market, green grocery and supermarket of the municipality. The samples were processed by a concentration method and evaluated by light microscopy for parasitological identification. Results: The percentage of contamination was 50.9% (55/108), with predominance of nematode larvae (36.5%), cysts of Entamoeba coli (26.0%) and eggs of hookworms/Strongyloides spp. (12.9%). Lettuce showed greater contamination rate (61.1%) and samples from the open street market were more contaminated (77.8%). Information collected at each point of sale pointed the field cultivation as the critical step for such contaminations. Conclusion: Vegeta...
Doencas alergicas e infeccoes produzidas por helmintos parasitos induzem uma resposta imune predo... more Doencas alergicas e infeccoes produzidas por helmintos parasitos induzem uma resposta imune predominantemente Th2, estimulando o aumento e ativacao de eosinofilos, basofilos, mastocitos e altos niveis de IgE circulantes. No caso da esquistossomose, a resposta Th2 e estimulada com o inicio da ovipostura e geralmente e acompanhada por aumento de IL-10, resultando em uma infeccao cronica modulada que persiste por anos. Alguns estudos epidemiologicos tem relatado associacoes inversas entre alergia e helmintoses, propondo que a exposicao frequente do sistema imune a agentes infecciosos pode levar ao desenvolvimento de uma resposta imune modulada, evitando, em parte, o desenvolvimento de doencas inflamatorias. Entretanto, a maioria dos trabalhos publicados tem sido realizados em areas com alta carga parasitaria, situacao que tem sido alterada em muitas areas endemicas brasileiras nos ultimos anos devido ao impacto dos programas de controle. Com o intuito de esclarecer alguns destes aspect...
Wild rodent species are naturally infected by Schistosoma mansoni; however, the genetic character... more Wild rodent species are naturally infected by Schistosoma mansoni; however, the genetic characterization of the parasite, its parasitological features, and its role in human schistosomiasis are poorly understood. In this study, we isolated and characterized Schistosoma from naturally infected Holochilus sciureus, called HS strain, collected from a schistosomiasis endemic region in Maranhão State, Brazil. To isolate the parasite, miracidia obtained from the livers of H. sciureus were used to infect Biomphalaria glabrata of sympatric (called SB) and allopatric (called BH) strains, and the produced cercariae were subcutaneously inoculated into hamsters and/or BALB/c mice. Parasitological kinetics in experimentally infected hosts were evaluated, and the 16S and cox 1 regions of mtDNA from isolated worms were amplified and sequenced. Only miracidia obtained from infected mice, but not from hamsters, were capable of infecting B. glabrata, allowing maintenance of the isolated parasite. Cox...
Schistosomiasis and Leishmaniasis are chronic parasitic diseases with high prevalence in some tro... more Schistosomiasis and Leishmaniasis are chronic parasitic diseases with high prevalence in some tropical regions and, due to their wide distribution, a risk of co-infections is present in some areas. Nevertheless, the impact of this interaction on human populations is still poorly understood. Thus, the current study evaluated the effect of previous American Tegumentary Leishmaniasis (ATL) on the susceptibility and immune response to Schistosoma mansoni infection in residents from a rural community in Northern of Minas Gerais state, Brazil, an area endemic for both parasitic infections. The participants answered a socioeconomic questionnaire and provided stool and blood samples for parasitological and immunological evaluations. Stool samples were examined by a combination of parasitological techniques to identify helminth infections, especially S. mansoni eggs. Blood samples were used for hemograms and to measure the serum levels of cytokines and chemokines. Reports on previous ATL wer...
The severity of chronic schistosomiasis has been mainly associated with the intensity and extensi... more The severity of chronic schistosomiasis has been mainly associated with the intensity and extension of the inflammatory response induced by egg-secreted antigens in the host tissue, especially in the liver and intestine. During acute schistosomiasis, eosinophils account for approximately 50% of the cells that compose the liver granulomas; however, the role of this cell-type in the pathology of schistosomiasis remains controversial. In the current study, we compared the parasite burden and liver immunopathological changes during experimental schistosomiasis in wild-type (WT) BALB/c mice and BALB/c mice selectively deficient for the differentiation of eosinophils (ΔdblGATA). Our data demonstrated that the absence of eosinophil differentiation did not alter the S. mansoni load or the liver retention of parasite eggs; however, there were significant changes in the liver immune response profile and tissue damage. S. mansoni infection in ΔdblGATA mice resulted in significantly lower liver concentrations of IL-5, IL-13, IL-33, IL-17, IL-10, and TGF-β and higher concentrations of IFN-γ and TNF-α, as compared to WT mice. The changes in liver immune response observed in infected ΔdblGATA mice were accompanied by lower collagen deposition, but higher liver damage and larger granulomas. Moreover, the absence of eosinophils resulted in a higher mortality rate in mice infected with a high parasite load. Therefore, the data indicated that eosinophils participate in the establishment and/or amplification of liver Th-2 and regulatory response induced by S. mansoni, which is necessary for the balance between liver damage and fibrosis, which in turn is essential for modulating disease severity.
The plasma level of the chemokine CCL3 is elevated in patients with chronic severe schistosomiasi... more The plasma level of the chemokine CCL3 is elevated in patients with chronic severe schistosomiasis mansoni. We have previously shown that CCL3 −/− mice with experimental infection showed diminished pathology and worm burden compared to those of wild-type (WT) mice. To elucidate further the role of CC chemokines during schistosomiasis mansoni infection, we evaluated the course of infection in C57BL/6J mice deficient in CCR5, one of the receptors for CCL3. The CCR5 deficiency proved to be remarkably deleterious to the host, since mortality rates reached 70% at 14 weeks postinfection in CCR5 −/− mice and 19% in WT mice. The increased lethality was not associated with an increased parasite burden, since similar numbers of eggs and adult worms were found in mice from both groups. Liver granulomas of chronically infected CCR5 −/− mice were larger and showed greater numbers of cells and collagen deposition than liver granulomas from WT mice. This was associated with higher levels of produc...
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