Testing albendazole resistance in Fasciola hepatica: validation of an egg hatch test with isolates from South America and the United Kingdom.

CANEVARI, J; CEBALLOS, L; SANABRIA, R; ROMERO, J; OLAECHEA, F; ORTIZ, P; CABRERA, M; GAYO, V; FAIRWEATHER, I; LANUSSE, C; ALVAREZ, L

JOURNAL OF HELMINTHOLOGY

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2013 vol. 19 p. 1 - 7

0022-149X

The main goal of the current work was to develop and validate an in vitro fluke egg hatch test, as a method for the detection of albendazole (ABZ) resistance in the liver fluke, Fasciola hepatica. Fluke eggs (200/ml, n ¼ 5) from six different isolates were used in the current experimental work. They were obtained from different geographical locations and named Cullompton (UK), CEDIVE (Chascomus, Argentina), INTA-Bariloche (Bariloche, Argentina), Rubino (Uruguay), Cajamarca (Peru´ ) and Rı´o Chico (Catamarca, Argentina). The fluke eggs were incubated (258C) for a 12-h period in the presence of either ABZ or its sulphoxide metabolite (ABZ.SO) (5, 0.5 or 0.05 nmol/ml). Untreated eggs were incubated as a control. Incubated eggs (with or without drug present) were kept in darkness at 258C for 15 days. Afterwards, the trematode eggs were exposed to daylight over a 2-h period. Hatched and unhatched eggs were evaluated using an optical microscope, and the ovicidal activity was assessed for each fluke isolate. A very low ovicidal activity (#13.4%) was observed in the ABZ-resistant CEDIVE isolate for both ABZ and ABZ.SO. Conversely, in the INTA-Bariloche and Rı´o Chico isolates, which are suspected to be susceptible to ABZ, ovicidal activities $ 70.3% were observed after incubation with ABZ at the lowest concentration tested (0.05 nmol/ml). This finding correlates with that previously