Papers by Silmara Allegretti
Scientia Plena, Apr 1, 2015
A bovinocultura é um dos principais destaques do agronegócio brasileiro no cenário mundial. O obj... more A bovinocultura é um dos principais destaques do agronegócio brasileiro no cenário mundial. O objetivo deste trabalho foi verificar a ocorrência de parasitas em vacas e bezerros no período de amamentação correlacionando com o peso dos mesmos, além de fazer a identificação das espécies de Eimeria spp. das amostras estudadas. Para tanto, as amostras fecais foram processadas por sedimentação e flutuação em solução salina saturada para quantificação dos ovos e oocistos por grama de fezes. Constatou-se a presença de Moniezia expansa, além das prevalências de 66% e 33% dos bovinos parasitados por helmintos e coccídeos respectivamente. A prevalência encontrada nas amostras dos bezerros foi maior que nas vacas com 46,6% para infecções concomitantes. Palavras-chave: bovinos, parasitas e período de lactação. Occurrence of gastrointestinal parasites in dairy cattle and their calves during the nursing period, at Fazenda São Paulinho, Municipality of Itapicuru / BA The cattle is one of the highlights of Brazilian agribusiness on the world stage. The aim of this study was to measure the weight and identify parasites in cows and calves during the nursing period correlating the weight for them, besides making the identification of species of Eimeria spp. of the studied samples. Fecal analyzes were processed by sedimentation and flotation in saturated saline solution for quantification of eggs and oocysts per gram of feces. The results showed presence of Moniezia expansa, prevalence of 66% and 33% of the animals infected with helminths and coccidia, respectively. Calves animals showed highest occurrence for 46,6% concomitant infections.
À Deus que sempre esteve presente, tornando superáveis os momentos difíceis e transformando os mo... more À Deus que sempre esteve presente, tornando superáveis os momentos difíceis e transformando os momentos de felicidade em inesquecíveis e por todas as oportunidades concedidas durante este percurso na minha vida. À minha querida mãe, Maria Aparecida Duart por todo amor, dedicação, confiança, conselhos, paciência e fé. A senhora sabe o quanto é grande o meu amor e o quanto é importante na minha vida! Aos meus padrinhos, Luiz Carlos Matthes In memorian e Neuza Matthes, vocês foram sem dúvida, as pessoas mais importantes na minha formação pessoal e profissional. v AGRADECIMENTOS Á Profª. Silmara Marques Allegretti, pela amizade, oportunidade, confiança, orientação, dedicação, incentivo e apoio durante todo este período de mestrado. E sem dúvida, por ter despertado desde a graduação o interesse e paixão pela parasitologia. Muito obrigada! Aos professores que fizeram parte do exame prévio deste trabalho: Marlene Tiduko Ueta, Luiz Augusto Magalhães, Mara Cristina Pinto, que com suas sugestões e análises críticas contribuíram valorosamente para o desenvolvimento deste trabalho. Ao Prof. Arício Xavier Linhares, pelo auxílio nas análises estatísticas.
v À Profa. Dra. Silmara Marques Allegretti, pela orientação, dedicação, disponibilidade e paciênc... more v À Profa. Dra. Silmara Marques Allegretti, pela orientação, dedicação, disponibilidade e paciência ao longo do mestrado e principalmente pela amizade e carinho que sempre demonstrou desde a minha chegada ao Departamento. À Coordenação da subcomissão de Pós Graduação em Parasitologia, na pessoa da Profa. Dra. Regina Maura Bueno Franco, pelo auxílio prestado. Aos membros da banca de exame prévio Profa.
Frontiers in Tropical Diseases
Schistosomiasis is a chronic neglected tropical disease saddling millions of people in the world,... more Schistosomiasis is a chronic neglected tropical disease saddling millions of people in the world, mainly children living in poor rural areas. Praziquantel (PZQ) is currently the only drug used for the treatment and control of this disease. However, the extensive use of this drug has brought concern about the emergence of PZQ-resistance/tolerance bySchistosoma mansoni. Studies ofSchistosomaspp. genome, transcriptome, and proteome are crucial to better understand this situation. In thisin vitrostudy, we compare the proteomes of aS. mansonivariant strain stably resistant to PZQ and isogenic to its fully susceptible parental counterpart, identifying proteins from male and female adult parasites of PZQ-resistant and PZQ-susceptible strains, exposed and not exposed to PZQ. A total of 60Schistosomaspp. proteins were identified, some of which present or absent in either strain, which may putatively be involved in the PZQ-resistance phenomenon. These proteins were present in adult parasites ...
O programa extensionista “Ciencia e Arte nas Ferias” vem acontecendo ha 12 anos na Universidade E... more O programa extensionista “Ciencia e Arte nas Ferias” vem acontecendo ha 12 anos na Universidade Estadual de Campinas (UNICAMP – Campinas/SP), durante os meses de ferias escolares de verao. A proposta visa promover a vivencia de alunos do ensino medio da rede publica de ensino de Campinas-SP e regiao com o ambiente universitario e laboratorios de pesquisa. Ao longo de nove anos, os projetos desenvolvidos no laboratorio de helmintologia promoveram atividades de pesquisa individuais e em grupo (oficinas) com os estudantes, com o objetivo de conscientizar e incentivar os alunos a serem disseminadores de informacoes sobre parasitoses/helmintiases no ambiente escolar e fora dele. Este artigo, portanto, se trata de um relato de experiencia do laboratorio, ressaltando a importância do programa extensionista no tratamento de parasitoses, uma vez que o “Ciencia e Arte nas Ferias” aliou a informacao e conscientizacao dos alunos a disseminacao desses conhecimentos para a sociedade.
Antimicrobial Agents and Chemotherapy, 2020
Praziquantel is currently the only drug available to treat schistosomiasis, a disease of enormous... more Praziquantel is currently the only drug available to treat schistosomiasis, a disease of enormous public health significance caused by a blood fluke of the genus Schistosoma . Diminazene, a drug approved by the FDA, has been successfully used to treat diseases caused by blood protozoan parasites. In this study, we evaluated the antiparasitic properties of diminazene against Schistosoma mansoni ex vivo and in mice harboring either chronic or early S. mansoni infections.
Data da defesa: 06/08/2009 Programa de Pós-Graduação: Parasitologia. iii iv Às mulheres da minha ... more Data da defesa: 06/08/2009 Programa de Pós-Graduação: Parasitologia. iii iv Às mulheres da minha vida: Fátima, esposa amada, dedicada e compreensiva, e Grazielle, mais que filha e amiga, um presente de Deus. v AGRADECIMENTOS -A Deus, o Autor da existência, por meio de quem "...vivemos, e nos movemos e existimos..." (Atos dos Apóstolos 17:28 / RA). -Aos meus pais, João Baptista Presotto e Itália Provasi Presotto que não só me legaram a vida e valores éticos e morais, mas também por terem me permitido percorrer o maravilhoso caminho da ciência. -À Universidade Estadual de Campinas (UNICAMP), por sua contribuição ao conhecimento, através do ensino, pesquisa e formação acadêmica, e também por disponibilizar aperfeiçoamento científico e profissional, através de programas de Pós-Graduação de alto nível e acessíveis aos profissionais que estão inseridos no mercado de trabalho. -À Professora Silmara Marques Allegretti, minha orientadora e mestre, por sua paciência, dedicação e incentivo, bem como por sua atitude sempre positiva e serena frente às dificuldades encontradas durante a realização deste estudo. -Ao Biólogo Rubens Riscala Madi, do Departamento de Biologia Animal, por sua contribuição na análise estatística dos dados deste estudo. -Aos demais professores do Departamento de Biologia Animal, por sua dedicação à pesquisa e ao ensino da parasitologia, disciplina tão importante para o bem da humanidade.
Interfaces Científicas - Saúde e Ambiente, 2017
Os trematódeos são helmintos que parasitam todas as classes de vertebrados e utilizam moluscos co... more Os trematódeos são helmintos que parasitam todas as classes de vertebrados e utilizam moluscos como hospedeiros intermediários. Esses parasitas apresentam fases aquáticas sendo possível encontrá-los em coleções de água-doce. Este trabalho teve por objetivo determinar as espécies de moluscos que atuam como hospedeiros intermediários de trematódeos em uma lagoa urbana no município de Campinas-SP. Foram realizadas coletas mensais entre maio e setembro de 2008, por meio de arrasto vertical do lodo, com auxílio de concha de captura em cinco pontos localizados na região central e margem da lagoa Chico Mendes. Foram coletados moluscos de quatro Gêneros: os Bivalves Corbicula sp. (Corbiculiidae) e Anodonta sp. (Mycetopodidae), e os Gastropodas Lymnaea sp. (Lymnaeidae) e Pomacea sp. (Ampullariidae). Apenas os gêneros Lymnaea sp. e Pomacea sp. apresentaram resultado positivo para a eliminação de cercárias dos tipos equinóstoma e anfístoma, respectivamente. O conhecimento dos ciclos biológicos...
Journal of Drug Delivery Science and Technology, 2020
Praziquantel (PZQ) is an anthelmintic drug, being the first choice for the treatment of schistoso... more Praziquantel (PZQ) is an anthelmintic drug, being the first choice for the treatment of schistosomiasis. Its high hydrophobic character and its low water solubility are the main limitations to the development of liquid formulations for the oral administration of the drug. The aim of this work was to develop Solid Lipid Nanoparticles (SLN) for the loading of PZQ for the treatment of S. mansoni infections. PZQ-SLN were produced by hot high shear homogenization. The obtained SLN exhibited a mean size of ~300 nm, with a polydispersity index of ~0.20, zeta potential of ~-28 mV and encapsulation efficiency of 92.31%. Thermal analysis demonstrated that the production process reduced the lipid crystallinity of the SLN matrices, which displayed a spherical morphology by scanning electron microscopy (SEM). The mathematical fitting of the release profile demonstrated that PZQ followed the Weibull model whereas PZQ-loaded SLN the Peppas model. PZQ-loaded SLN were more effective in inducing S. mansoni death than PZQ alone. The increased drug solubility did not exhibit toxicity against human fibroblast cell lines (L929). PZQ-loaded SLN demonstrated great parasiticidal properties, being an improved alternative to the classical treatment of schistosomiasis.
The extensive use of Praziquantel (PZQ), the only drug available to treat schistosomiasis, has br... more The extensive use of Praziquantel (PZQ), the only drug available to treat schistosomiasis, has brought concern about the emergence of PZQ-resistance/tolerance bySchistosomaspp., thus reaffirming an urge for the development of new treatment alternatives. Therefore, it is imperative and urgent to study this phenomenon trying to understand what is involved in its occurrence. Studies ofSchistosomaspp. genome, transcriptome and proteome are crucial to better understand this situation. By stepwise drug pressure from a fully susceptible parasite strain, our group selected aS. mansonivariant strain stably resistant to PZQ and isogenic to its fully susceptible parental counterpart, except for the genetic determinants of PZQ-resistance phenotype. Based on this, the objective of this study was to compare the proteomes of both strains, identifying proteins from male and female adult worms of PZQ-resistant and PZQ-susceptible strains, exposed and not exposed to PZQ, which were separated by high-...
PloS one, 2018
Schistosomiasis is a disease caused by parasites of the genus Schistosoma, currently affecting mo... more Schistosomiasis is a disease caused by parasites of the genus Schistosoma, currently affecting more than 200 million people. Among the various species of this parasite that infect humans, S. mansoni is the most common. Pharmacological treatment is limited to the use of a single drug, praziquantel (PZQ), despite reports of parasite resistance and low efficacy. It is therefore necessary to investigate new potential schistosomicidal compounds. In this study, we tested the efficacy of epiisopilosine (EPIIS) in a murine model of schistosomiasis. A single dose of EPIIS (100 or 400 mg/kg) administered orally to mice infected with adult S. mansoni resulted in reduced worm burden and egg production. The treatment with the lower dose of EPIIS (100 mg/kg) significantly reduced total worm burden by 60.61% (P < 0.001), as well as decreasing hepatosplenomegaly and egg excretion. Scanning electron microscopy revealed morphological changes in the worm tegument after treatment. Despite good activ...
Frontiers in Pharmacology, 2016
Schistosomiasis is a parasitic disease caused by several species of trematode worms and it is bel... more Schistosomiasis is a parasitic disease caused by several species of trematode worms and it is believed that more than 261 million people are affected worldwide. New drug development has become essential because there is a risk of the parasite becoming resistant to Praziquantel, the only drug available for this infection. This study evaluated parasitological, immunological and histological parameters in mice infected with Schistosoma mansoni and treated with an herbal commercial medicine. This drug consists of menthol (30-55%) and menthone (14-32%). A 60 day treatment regimen with the herbal medicine decreased the number of S. mansoni eggs in the feces, liver, and intestine and reduced the number of hepatic granulomas. We observed a reduction of 84% in blood eosinophilia and a decrease in the IL-4 and IL-10 blood levels after treatment. Therefore, we propose that schistosomiasis treatment with this herbal medicine for 60 days has an immunomodulatory and anti-inflammatory action in this animal model for schistosomiasis thus contributing to the decrease in physio pathological effects caused by S. mansoni infection.
Frontiers in Microbiology, 2016
Schistosomiasis is one of the most common human parasitic diseases whose socioeconomic impact is ... more Schistosomiasis is one of the most common human parasitic diseases whose socioeconomic impact is only surpassed by malaria. Praziquantel (PZQ) is the only drug commercially available for the treatment of all schistosome species causing disease in humans. However, there has been stronger evidences of PZQ-resistance on Schistosoma mansoni and thus it is very important to study the phenotypic characteristics associated with it. The aim of this study was to evaluate morphological alterations in S. mansoni PZQ-resistant adult worms and eggs, by comparing a PZQ-resistant strain obtained under PZQ drug pressure with a PZQ-susceptible strain. For this, scanning electronic microscopy was used to assess tegumental responsiveness of both strains under PZQ exposure, and optical microscopy allowed the monitoring of worms and eggs in the presence of the drug. Those assays showed that PZQ-susceptible worms exposed to the drug had more severe tegumental damages than the resistant one, which had only minor alterations. Moreover, contrary to what occurred in the susceptible strain, resistant worms were viable after PZQ exposure and gradually regaining full motility after removal of the drug. Eggs from resistant strain parasites are considerably smaller than those from susceptible strain. Our results suggest that there might be a difference in the tegument composition of the resistant strain and that worms are less responsive to PZQ. Changes observed in egg morphology might imply alterations in the biology of schistosomes associated to PZQ-resistance, which could impact on transmission and pathology of the disease. Moreover, we propose a hypothetical scenario where there is a different egg tropism of the S. mansoni resistant strain. This study is the first comparing two strains that only differ in their resistance characteristics, which makes it a relevant step in the search for resistance determinants.
Revista de Patologia Tropical, 2015
Interdisciplinary Perspectives on Infectious Diseases, 2012
The increased pathogenesis of theSchistosoma mansoniBH strain compared with the SJ strain has bee... more The increased pathogenesis of theSchistosoma mansoniBH strain compared with the SJ strain has been attributed to the number of granulomas formed in experimental infections, which increase the mortality in definitive hosts. The aim of the present study was to investigate the development of granulomas around the eggs of theS. mansoniBH and SJ strains and to determine whether this host reaction was strain specific. Four experimental groups were analyzed. Two groups contained mice inoculated in the caudal vein with eggs from theS. mansoniBH or SJ strains and the other two contained mice that were infected with cercariae of the BH strain prior to being inoculated with eggs. The number of granulomas per tissue area in the lungs and liver, as well as the size of the granulomas, was analyzed to characterize the response to schistosome infection. The largest granulomatous responses were observed around eggs of the BH strain. Granulomas covered a larger area in the lungs of mice that were pre...
Revista Brasileira de Parasitologia Veterinária, 2011
Twenty horses naturally infected with nematodes were included in a blind, controlled field study ... more Twenty horses naturally infected with nematodes were included in a blind, controlled field study on efficacy and safety of an oral 2% ivermectin formulation at a dose of 0.2 mg.kg-1. Horses were divided into treated and non-treated (control) groups with ten animals each based on preliminary counts of eggs per gram of feces (EPG). Stool samples were collected after treatment for identification of nematode species. Clinical evaluations and EPG counts were performed on days 0, +5, +14 and +19. Nineteen nematode species were identified: Coronocyclus ulambajari, Craterostomum acuticaudatum, Cyathostomum catinatum, Cyathostomum pateratum, Cylicocyclus brevicapsulatus, Cylicocyclus insigne, Cylicocyclus leptostomum, Cylicocyclus nassatus, Cylicocyclus ultrajectinus, Cylicocyclus spp., Cylicostephanus calicatus, Cylicostephanus longibursatus, Cylicostephanus poculatus, Habronema muscae, Habronema spp., Parascaris equorum, Poteriostomum imparidentatum, Oxyuris equi and Triodontophorus spp. T...
Brazilian Journal of Biology, 2009
The behaviour of the albino and melanic variants of Biomphalaria glabrata of Belo Horizonte (MG. ... more The behaviour of the albino and melanic variants of Biomphalaria glabrata of Belo Horizonte (MG. Brazil) was studied comparatively, in terms of their respective susceptibilities to infection by Schistosoma mansoni of the same origin, through observation of the elimination of cercariae for a three-month period and the calculation of mortality and infection rates, in control and in infected snails. The number of amoebocytes, granulocytes and hyalinocytes in the circulating hemolymph during different periods of infection was analyzed. The evolution of the infection in the tissues was observed by means of histological cross-sections. The melanic variant showed greater susceptibility to infection and a higher mortality rate. The albino variant showed a higher number of circulating amoebocytes, both granulocytes and hyalinocytes. A higher number of degenerated sporocysts were seen in the histological cross-sections of the albino variant. The results suggest that the melanic variant of B. ...
Revista de Patologia Tropical, 2013
Different strains of Schistosoma mansoni can respond differently to conventional and experimental... more Different strains of Schistosoma mansoni can respond differently to conventional and experimental treatments. Therefore, the responses to potential schistosomicidal drugs must be checked with different parasite strains. This work aimed to analyze changes caused by different concentrations of artemisinin or artesunic acid administered on different days in the teguments of adult S. mansoni belonging to two Brazilian strains (BH and SJ), using scanning electron microscopy (SEM). Infected mice were treated with 300 or 500 mg/kg of artemisinin and artesunic acid, 30 or 45 days post infection. Fifteen days after treatment, worms were examined by SEM. Altered teguments were observed in males and females on both days of treatment with both compounds, but the injury with artesunic acid was more intense. The treatment utilizing 500 mg/kg of artesunic acid against the BH strain 30 days after the infection proved to be particularly effective, resulting in erosion, peeling, sensory structure damage, and vesicle formation on the tegument of males and females. It is concluded that artemisinin and artesunic acid showed qualitatively similar tegumentary changes in both genders of the BH and SJ parasite strains. However, changes induced by artesunic acid were more severe for the BH strain, which demonstrates greater susceptibility of this strain to this experimental treatment.
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Papers by Silmara Allegretti