Evidence of Fasciola spp. resistance to albendazole, triclabendazole and bromofenofos in water buffaloes (Bubalus bubalis)

Fasciolosis caused by Fasciola spp. is considered the most important helminth infection of ruminants in tropical countries. Anthelmintic resistance has become a global concern. This study compared the efficacy of the commonly used anthelmintics, determined the toxicity level and any indication of resistance. Thirty two water buffaloes naturally-infected with Fasciola spp. were used to determine the efficacy of triclabendazole (TBZ), albendazole (ABZ), and bromofenofos (BRO) using Fecal Egg Count Reduction Test (FECRT). To test the toxicity of the drugs given, serum glutamic-pyruvic transaminase (SGPT) was evaluated before and within one week after treatment. One dose administration of ABZ registered an efficacy of 79.17%, 73.33% for TBZ and 70.83% for BRO. Efficacy in two dosetreatment group was 83.33% for both BRO and ABZ, and 90.00% for TBZ. Two dose-treatment was effective for TBZ (90%), ineffective for BRO and ABZ. SGPT levels were not significantly different between pre-treatment and posttreatment across all treatments. Giving one or two doses of anthelmintics, at one month interval, does not increase the efficacy of the three drugs tested. The study also implies that anthelmintic resistance may have developed in the animals

Development and application of a quantitative real-time PCR for the diagnosis of Surra in water buffaloes

Trypanosoma evansi (T. evansi) causes the disease called Surra in domestic animals, which is of great economic importance in South Asian countries. In order to improve the diagnosis of Surra, we endeavored to develop a real-time PCR assay for the detection and quantification of parasites in water buffaloes using specific primers for the T. evansi Rode Trypanozoon antigen type (RoTat) 1.2 Variable Surface Glycoprotein (VSG) gene, which is a known diverse DNA region in trypanosomes. The quantitative detection limit of the assay was 102 trypanosomes per mL of blood, and the identity of the amplicon was confirmed in all assays by melting curve analysis. To evaluate the clinical applicability of this procedure, detection and estimation of parasitemia in blood samples obtained from water buffaloes and horses were conducted. T. evansi was detected in 17/607 (2.8%) blood samples, with parasitemia levels ranging from >101 to 107 parasites per mL of blood. Interestingly, out of the 17 PCR positive animals, 3 had previously received trypanocidal treatment and 1 had abortion history. These data indicate that real-time PCR for the estimation of putative parasitemia levels is a quantitatively and objectively applicable technique for clinical diagnosis of Surra, and could help to understand disease stage and risk of transmission of T. evansi

Diet of a catfish before and after damming of the salto caxias reservoir, iguaçu river

This study evaluated the diet of Pimelodus sp., before and after damming of Salto Caxias, (waterfall in the Iguaçu river), as well spatial and ontogenetic diet shift. Surveys were carried out from March 1997 to February 1998 (before damming) and from April 1999 to January 2000 (after damming) inside the reservoir and adjacent tributaries. Stomach contents analysis of 682 specimens revealed omnivory with high degree of trophic opportunism to this species. Analysis of variance (three way ANOVA) for scores produced from Detrended Correspondence Analysis (DCA) yielded a significant interaction between the damming phases and size of the individuals (juveniles and adults) (F = 4.68; P = 0.04). After damming, adults exploited mainly fish, whereas the juveniles fed mostly on plants, dipterans larvae and scales at different sites. From significant differences in the ordination among the factors considered, it could be inferred that the diet of Pimelodus sp. was influenced by the formation of the reservoir and this depended on the life stage considered. Position of the sites (feeding grounds) did not lead to significant alterations in diet.<br>Esse estudo avaliou a dieta de Pimelodus sp., antes e após o represamento de Salto Caxias, no rio Iguaçu, bem como variações espaciais e ontogenéticas na dieta da espécie. As amostragens foram realizadas antes do represamento (março/97 a fevereiro/98) e no período posterior (abril/99 a janeiro/00), no corpo principal do reservatório e tributários adjacentes. A análise de conteúdos estomacais de 682 exemplares revelou que esta espécie é onívora com elevado oportunismo trófico. Após o represamento, indivíduos adultos exploraram principalmente peixes, enquanto que os juvenis consumiram especialmente plantas, larvas de Diptera e escamas em diferentes locais de coleta. A análise de variância (ANOVA trifatorial) aplicada sobre os escores da análise de correspondência com remoção do efeito do arco (DCA), mostrou uma interação significativa (F = 4.68; P = 0.04) entre as fases de represamento e o tamanho dos indivíduos (juvenis e adultos). Uma vez determinada as diferenças significantes na ordenação entre os fatores considerados, nós podemos inferir que a dieta de Pimelodus sp. foi influenciada pela formação do reservatório e isso dependeu do tamanho dos indivíduos. As análises por locais de coleta não mostraram diferenças significantes na dieta