In vitro studies for evaluation of dosage-effect relationships for benzimidazoles in Parascaris equorum
Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
One of the most pathogenic internal parasites of horses is the large roundworm, Parascaris equroum, which mainly infects foals and young horses. The roundworm infection is treated with anthelmintic drugs, but due to the extensive usage of anthelmintics for several decades, this parasite has developed resistance and the only anthelmintic class that still shows 100% effect against P. equorum is the benzimidazoles.
In this study, P. equorum eggs from different studs were exposed to rising concentrations of thiabendazole (TBZ), a model substance of benzimidazoles. The influence of TBZ on the development from egg to larvae was studied, dose-effect relationships were established, and the EC50 values were calculated to analyze the sensitivity to benzimidazole drugs. In addition, influence of TBZ on the development from egg to larvae was also studied in different temperatures and DMSO concentrations.
The statistical analysis showed that there were no significant differences in the EC50 values between the different studs, and the conclusion is that no resistance against benzimidazoles could be observed in these studs.
The results showed that there were numerical differences between the EC50 values obtained from exposures with 0.5% DMSO, as these were lower than in 1% DMSO. This indicates that DMSO could have a protecting effect on the eggs. The optimal temperature for this study was between 20 and 25°C, since dose-effect relationships could be observed at these temperatures. 15°C was too low for development to occur, and in 37°C all eggs exposed to TBZ stopped developing. This could implicate that higher temperatures potentiate the effect of TBZ.
Place, publisher, year, edition, pages
2013. , 36 p.
Parascaris equorum, anthelmintic resistance, benzimidazoles, thiabendazole, dosage-effect relationship
Pharmacology and Toxicology
IdentifiersURN: urn:nbn:se:uu:diva-203243OAI: oai:DiVA.org:uu-203243DiVA: diva2:635844
Section for Parasitology, Department of Biomedical Sciences and Veterinary Public Health, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences
Subject / course
Master of Science Programme in Pharmacy
Tydén, Eva, PhDHöglund, Johan, Professor in Parasitology
Roman, Erika, PhD, Associate Professor in Behavioral Neurobiology and Pharmacology