Mariana Drummond Costa Ignacchiti

Efeito moluscicida do óleo essencial de Cymbopogon winterianus Jowitt (Poaceae) sobre Lymnaea columella (Say, 1817) e Biomphalaria tenagophila(D’Orbigny, 1835)

Conventional molluscicides have been employed to control of planorbids vectors and are an important tool in order to control the hepatic fascioliasis and schistosomiasis. Thus, these substances have been showinggreat relevance for both Veterinary and Livestock Services as well as for Epidemiology and Disease Surveillance. On the other hand, the process of drug pressure for the selection of resistant snails to such components and their low selectivity have stimulated the search for new substances. Since researches on new drugs are the starting point to assist on themolluscs control, this work was developed in order to evaluate the effect of Cymbopogon winterianus Jowitt essential oil on L. columella and B. tenagophila, intermediate hosts of Fasciola hepatica and Schistosoma mansoni, respectively. The essential oil was obtained from fresh leaves by hydrodistillation using a Clevenger apparatus. A qualitative analysis was performed by gas chromatography together with a mass spectrometry one (GC/MS) and the chemical constituent content was determined by gas chromatography with a flame ionization detector (GC/FID). The molluscicidal effect was evaluated through the use of six snails of each species and C. winterianus essential oil at 10, 20, 30, 40, 60, 80 and 100 ppm. The result of the gas chromatographic analysis for the essential oil showed geraniol (28.62%), citronellal (23.62%) and citronellol (17.10%) as the major chemical components . The DL100 and DL50 values for L. columella and B. tenagophila species were, respectively, 60 and 40 ppm; 80 ppm and 60 ppm. L. columella had demonstrated more sensitivity to this essential oil than theB. tenagophila species. The C. winterianus essential oil proved to be a promising alternative for the control of these molluscs being the L. columella species the most sensitive of them.

Comparação de kits ELISA® comerciais para anticorpos no soro e leite com um teste coproparasitológico em bovinos naturalmente infectados por Fasciola hepatica

A fasciolose e uma enfermidade causada por um trematoda que acomete o figado principalmente de ruminantes domesticos, podendo parasitar o homem e seu diagnostico e realizado rotineiramente por exames coproparasitologicos. O objetivo do presente estudo foi comparar kits comerciais de ELISA para anticorpos no soro e leite com um teste coproprarasitologico em bovinos naturalmente infectados por Fasciola hepatica. Foram coletadas amostras de fezes (92) sangue (92) e leite (43) de bovinos provenientes de propriedades de gado leiteiro do municipio de Jeronimo Monteiro, sul do Estado do Espirito Santo. As amostras de fezes coletadas foram processadas pela tecnica de sedimentacao fecal para ovos de F. hepatica, utilizada como padrao ouro para as analises. Amostras de sangue e de leite foram processadas segundo a orientacao do fabricante dos respectivos Kits ELISA comerciais testados. Utilizou-se o c2 de McNemar para comparacao estatistica e calcularam-se a sensibilidade e especificidade, valores preditivos e kappa. Os resultados obtidos mostraram que as frequencias de positividade pelo uso dos kits ELISA comerciais de soro e de leite diferiram significativamente (p<0,0001) em relacao ao exame coproparasitologico. A sensibilidade dos Kits foi de 100%, porem possuiram baixa especificidade, 42,85 e 30% para o soro e leite respectivamente. O coeficiente de kappa mostrou concordância sofrivel para os testes de soro (0,33) e de leite (0,21). Os valores preditivos positivos dos kits para soro e leite foram, respectivamente, 44,61 e 38,23% e, os valores preditivos negativos de 100% para ambos os testes. Apesar da maior sensibilidade dos kits ELISA comerciais e, destes apresentarem diferenca em relacao ao exame coproparasitologico na deteccao dos animais positivos para F. hepatica, a escolha de um teste diagnostico deve considerar o custo beneficio. Quando se trata da presenca de parasitismo em rebanhos, o tratamento e aplicado em todos os animais e, assim, o exame coproparasitologico para o diagnostico da doenca tem maior eficiencia, ja que e menos oneroso e de facil execucao.

Kit comercial de ELISA® para a detecção de coproantígenos e exame coproparasitológico em bovinos com fígados condenados por fasciolose

The aim of this study was to compare a commercial ELISA kit for detection on coproantigen examination and fecal sedimentation using as gold standard inspection diagnosis of bovine livers at slaughter. In addition, we evaluated the correlation between the measured intensity of infection by counting eggs in the feces and the parasites in bovine livers. Feces were collected and evaluated macroscopically of 81 cattle livers, 45 of which had livers condemned by liver flukes and in these livers parasites were counted. Two fractions of stool samples collected were separated and one stored in freezer for further ELISA and other one processed according to sedimentation technique for diagnosis Fasciola hepatica. The Spearman correlation and McNemar chi-square were used, adopting the significance of 5%. In eight bovine livers condemned by the characteristic lesions of fascioliasis parasite were not found. The stool examinations and ELISA testing for detection coproantigen, respectively, had sensitivity of 51.11% and 75.55%, specificity of 100% and 91,66%, predictive positive value was 100% and 91.89%, predictive negative value 62% and 75% and kappa 0.48 and 0.65. The results obtained by commercial® ELISA kit did not differ (P=0,06) obtained at slaughterhouse, but the stool examinations differed (P<0.0001) in the detection of the positive animals. The correlation between the number of parasites in the liver and the number of eggs in the feces was moderate (rs=0.5757, P<0.0001). The commercial ELISA kit® was more sensitive than the fecal test, althought this one shoud not be discarded because of their efficiency.