In vitro and in silico evaluation of the schistosomicidal activity of eugenol derivatives using biochemical, molecular, and morphological tools

Background Eugenol shows both antibacterial and antiparasitic activities, suggesting that it might be evaluated as an option for the treatment of praziquantel-resistant schistosome. Methods The in vitro activities of three eugenol derivatives (FB1, FB4 and FB9) on adult worms from Schistosoma mansoni were examined by fluorescence and scanning electron microscopy to analyze effects on the excretory system and integument damage, respectively. Biochemical tests with verapamil (a calcium channel antagonist) and ouabain (a Na+/K+-ATPase pump inhibitor) were used to characterize eugenol derivative interactions with calcium channels and the Na+/K+-ATPase, while in silico analysis identified potential Na+/K+-ATPase binding sites. Results The compounds showed effective doses (ED50) of 0.324 mM (FB1), 0.167 mM (FB4), and 0.340 mM (FB9). In addition, FB4 (0.322 mM), which showed the lowest ED50, ED90 and ED100 (p < 0.05), caused the most damage to the excretory system and integument, according to both fluorescence and scanning electron microscopy analysis. The death of adult worms was delayed by ouabain treatment plus FB1 (192 versus 72 hours) and FB9 (192 versus 168 hours), but the response to FB4 was the same in the presence or absence of ouabain. Besides, no changes were noted when all of the eugenol derivatives were combined with verapamil. Moreover, FB1 and FB9 inhibited Na+/K+-ATPase activity according to in silico analysis but FB4 did not show a time-dependent relationship and may act on targets other than the parasite Na+/K+-ATPase. Conclusion Eugenol derivatives, mainly FB4 when compared to FB1 and FB9, seem to act more effectively on the integument of adult S. mansoni worms.(AU)

Seroepidemiological aspects of human infection by Strongyloides stercoralis in Alfenas, southern Minas Gerais, Brazil

Abstract INTRODUCTION: In most Strongyloides stercoralis infected individuals, nematoidosis occurs asymptomatically, but in immunocompromised patients, it can cause hyperinfection. Serological techniques seem to be a good alternative for detecting this parasite. METHODS The frequency of seropositivity for strongyloidiasis in Alfenas, MG, was estimated using the enzyme linked immunosorbent assay on blood samples, between May and August of 2015. RESULTS: Out of 258 samples tested, 53.9% were positive, and the frequency of seropositive individuals was higher in the peripheral districts of the municipality. CONCLUSIONS: The results indicate high seropositivity rates for strongyloidiasis among the residents of Alfenas city.

Prevalence and risk factors for intestinal parasitic infections in children attending daycare centers in Alfenas, southern Minas Gerais, Brazil

Intestinal parasitic infections are common among pre-school children in developing countries and they are often associated with gastrointestinal morbidity such as chronic diarrhea and malnutrition. Their circulation is mainly associated with lack of personal hygiene and environmental sanitation, as well as limited housing and food conditions. As the diagnosis of intestinal parasites is not a simple procedure, especially in population studies, due to difficulties encountered in strategies to obtain fecal samples, reliable prevalence data are scarce. Indeed, the epidemiological data on the prevalence of these parasites in different locations are important for the development of appropriate control measures. This study aimed to investigate the prevalence and risk factors associated with intestinal parasitic infection in children attending three public municipal daycare centers in Alfenas, MG. Three fecal samples from each child were collected on alternate days and processed by the spontaneous sedimentation technique and also through the commercially available centrifugal concentration technique, known as the TF-Test® (TFT). Information on the biological, social and physical environment, in which the children lived, were obtained through the application of a socio-epidemiological questionnaire to the parents or guardians and daycare staff. Giardia duodenalis was the parasite species most frequently detected among the children, with a positive rate of 27.8% (77/277). Entamoeba coli was detected in one of the daycare centers studied, with positivity rate of 43.7%, (7/16); and helminth infection in only two children. The present study showed that children of municipal daycare centers in Alfenas could be at risk of infection by intestinal parasites.

Aspectos epidemiológicos da esquistossomose em área dosudoeste de Minas Gerais, Brasil / Epidemiological aspects of schistosomiasis in area at the southwest of Minas Gerais, Brazil

Este estudo foi desenvolvido com o objetivo de contribuir com a vigilância da esquistossomose,no âmbito da Superintendência Regional de Saúde de Alfenas, MG, na mesorregião Sul/Sudoestedo estado, considerada não endêmica para a esquistossomose, ao contrário de outras áreas ao norte e nordeste do estado. Durante o ano de 2015, os escolares e migrantes de dois municípios dessa região, Arceburgo e Guaranésia, foram submetidos aos inquéritos parasitológico esorológico. No inquérito parasitológico, nenhum caso de esquistossomose foi detectado emArceburgo. Em Guaranésia, ovos de S. mansoni foram detectados entre os migrantes, com taxa de positividade de 13,6% (9/66), e em um único estudante. Sete membros da família, classificadacomo moradora de Guaranésia, mas determinada como oriunda de Timbaúba, PE quando investigada pela vigilância epidemiológica, foram também positivos para S. mansoni. No inquéritosorológico, a positividade para esquistossomose foi de 18,5% entre os migrantes de Guaranésia.Em relação às demais parasitoses, as taxas de positividade variaram de 12,5% a 32,3%. Os resultados sugerem diferenças em relação ao risco de exposição a S. mansoni e a importância da vigilância epidemiológica, mesmo em áreas não endêmicas, com foco nos migrantes, quando estes são oriundos de regiões endêmicas para esquistossomose.

This study was developed aiming at contributing to the schistosomiasis surveillance, within the scope of the Regional Health Superintendence of Alfenas, MG, in the South/Southwestmesoregion of the state, considered not endemic for schistosomiasis, unlike North and Northeast areas of the state. During the year of 2015, schoolchildren and migrants from two municipalitiesof this region, Arceburgo and Guaranésia, underwent parasitological and serological surveys.In the parasitological survey, no case of schistosomiasis was detected in Arceburgo. In Guaranésia, S. mansoni eggs were detected among the migrants, with a positivity rate of 13.6% (9/66),and in only one schoolchild. Seven members of his family, who were classified as residents of Guaranésia, but were determined as coming from Timbaúba, PE, when investigated by theepidemiological surveillance, they were also positive for S. mansoni. In the serological survey, the positivity for schistosomiasis was 18.5% among migrants from Guaranésia. Concerningthe other intestinal parasites, the positivity rates ranged from 12.5% to 32.3%. The results suggest differences in the risk of exposure to S. mansoni and the importance of epidemiologicalsurveillance, even in non-endemic areas, with a focus on migrants when they come from endemic regions for schistosomiasis.

Aspectos epidemiológicos da esquistossomose em área do sudoeste de Minas Gerais, Brasil / Epidemiological aspects of schistosomiasis in area at the southwest of Minas Gerais, Brazil

This study was developed aiming at contributing to the schistosomiasis surveillance, within the scope of the Regional Health Superintendence of Alfenas, MG, in the South/Southwest mesoregion of the state, considered not endemic for schistosomiasis, unlike North and Northeast areas of the state. During the year of 2015, schoolchildren and migrants from two municipalities of this region, Arceburgo and Guaranésia, underwent parasitological and serological surveys. In the parasitological survey, no case of schistosomiasis was detected in Arceburgo. In Guaranésia, S. mansoni eggs were detected among the migrants, with a positivity rate of 13.6% (9/66), and in only one schoolchild. Seven members of his family, who were classified as residents of Guaranésia, but were determined as coming from Timbaúba, PE, when investigated by the epidemiological surveillance, they were also positive for S. mansoni. In the serological survey, the positivity for schistosomiasis was 18.5% among migrants from Guaranésia. Concerning the other intestinal parasites, the positivity rates ranged from 12.5% to 32.3%. The results suggest differences in the risk of exposure to S. mansoni and the importance of epidemiological surveillance, even in non-endemic areas, with a focus on migrants when they come from endemic regions for schistosomiasis.

Este estudo foi desenvolvido com o objetivo de contribuir com a vigilância da esquistossomose, no âmbito da Superintendência Regional de Saúde de Alfenas, MG, na mesorregião Sul/Sudoeste do estado, considerada não endêmica para a esquistossomose, ao contrário de outras áreas ao norte e nordeste do estado. Durante o ano de 2015, os escolares e migrantes de dois municípios dessa região, Arceburgo e Guaranésia, foram submetidos aos inquéritos parasitológico e sorológico. No inquérito parasitológico, nenhum caso de esquistossomose foi detectado em Arceburgo. Em Guaranésia, ovos de S. mansoni foram detectados entre os migrantes, com taxa e positividade de 13,6% (9/66), e em um único estudante. Sete membros da família, classificada como moradora de Guaranésia, mas determinada como oriunda de Timbaúba, PE quando investigada pela vigilância epidemiológica, foram também positivos para S. mansoni. No inquérito sorológico, a positividade para esquistossomose foi de 18,5% entre os migrantes de Guaranésia. Em relação às demais parasitoses, as taxas de positividade variaram de 12,5% a 32,3%. Os resultados sugerem diferenças em relação ao risco de exposição a S. mansonie a importância da vigilância epidemiológica, mesmo em áreas não endêmicas, com foco nos migrantes, quando estes são oriundos de regiões endêmicas para esquistossomose.