ALVAREZ Luis Ignacio
The egg hatch test: A useful tool for albendazole resistance diagnosis in Fasciola hepatica
CEBALLOS, LAURA; CANTON, CANDELA; PRUZZO, CESAR; SANABRIA, RODRIGO; MORENO, LAURA; SANCHIS, JAIME; SUAREZ, GONZALO; ORTIZ, PEDRO; FAIRWEATHER, IAN; LANUSSE, CARLOS; ALVAREZ, LUIS; VALLADARES, MARÍA MARTINEZ
ELSEVIER SCIENCE BV
Año: 2019 vol. 271 p. 7 - 13
In the current study, the egg hatch test (EHT) has been evaluated as an in vitro technique to detect albendazole(ABZ) resistance in Fasciola hepatica. The intra- and inter-assay variations of the EHT were measured by means ofthe coefcient of variation in diﬀerent ﬂuke isolates and over time; then, the results of the EHT were comparedwith the ?gold standard? controlled efcacy test, which assesses the in vivo anthelmintic efcacy. The EHT wasused later to evaluate the intra-herd variability regarding the level of ABZ resistance in calves infected by thesame ﬂuke isolate. Finally, several factors of the initial protocol were modifed to improve the simplicity of theassay, including the incubation time of eggs with the drug and the use of eggs collected from faeces. The greatestuniformity between results within the assay and over time until 8 weeks after gallbladder collection (thedeadline proposed for egg analysis) was obtained with an ABZ concentration of 0.5 μM. The length of exposureto ABZ was shown to be critical, as prolonged incubation (15 days) led to a change of ovicidal activity. The ABZconcentration of 0.5 μM is suggested as a possible discriminating dose to predict ABZ resistance, due to the closeagreement between the results of the EHT at an ABZ concentration of 0.5 μM and those of the in vivo assays.