title: Testing albendazole resistance in Fasciola hepatica: validation of an egg hatch test with isolates from South America and the United Kingdom.
abstract: 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= 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 (Perú) and Río Chico (Catamarca, Argentina). The fluke eggs were incubated (25 °C) 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 25 °C 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 Río 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 described for the ABZ-susceptible Cullompton. Finally, the Cajamarca and Rubino isolates behaved as ABZ resistant, since no ovicidal activity was observed after eggs were incubated with ABZ at 0.5 nmol/ml. Considering the specific results obtained for each isolate under assessment, the egg hatch test described here may be a suitable method for detection of ABZ resistance in F. hepatica.
authors.affiliation: Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET, Facultad de Ciencias Veterinarias, UNCPBA, Campus Universitario,7000Tandil,Argentina.
authors.forename: J
authors.initials: J
authors.lastname: Canevari
authors.affiliation: Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET, Facultad de Ciencias Veterinarias, UNCPBA, Campus Universitario,7000Tandil,Argentina.
authors.forename: L
authors.initials: L
authors.lastname: Ceballos
authors.affiliation: Centro de Diagnóstico e Investigaciones Veterinarias (CEDIVE), Facultad de Ciencias Veterinarias, Universidad Nacional de la Plata,7130Chascomús,Argentina.
authors.forename: R
authors.initials: R
authors.lastname: Sanabria
authors.affiliation: Centro de Diagnóstico e Investigaciones Veterinarias (CEDIVE), Facultad de Ciencias Veterinarias, Universidad Nacional de la Plata,7130Chascomús,Argentina.
authors.forename: J
authors.initials: J
authors.lastname: Romero
authors.affiliation: Grupo de Salud Animal, INTA Bariloche,Rio Negro, CC 277,8400Bariloche,Argentina.
authors.forename: F
authors.initials: F
authors.lastname: Olaechea
authors.affiliation: Facultad de Ciencias Veterinarias, Universidad Nacional de Cajamarca,Cajamarca,Perú
authors.forename: P
authors.initials: P
authors.lastname: Ortiz
authors.affiliation: Facultad de Ciencias Veterinarias, Universidad Nacional de Cajamarca,Cajamarca,Perú
authors.forename: M
authors.initials: M
authors.lastname: Cabrera
authors.affiliation: Instituto DILAVE, 'Miguel C. Rubino',Montevideo,Uruguay.
authors.forename: V
authors.initials: V
authors.lastname: Gayo
authors.affiliation: Parasite Therapeutics Research Group,School of Biological Sciences, Medical Biological Centre, The Queen's University of Belfast,97 Lisburn Road,BelfastBT97BL,United Kingdom.
authors.forename: I
authors.initials: I
authors.lastname: Fairweather
authors.affiliation: Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET, Facultad de Ciencias Veterinarias, UNCPBA, Campus Universitario,7000Tandil,Argentina.
authors.forename: C
authors.initials: C
authors.lastname: Lanusse
authors.affiliation: Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET, Facultad de Ciencias Veterinarias, UNCPBA, Campus Universitario,7000Tandil,Argentina.
authors.forename: L
authors.initials: L
authors.lastname: Alvarez
mesh_terms: D015766:Albendazole / Q000494:pharmacology*; D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology*; D004351:Drug Resistance; D005210:Fasciola hepatica / Q000187:drug effects* / Q000502:physiology; D021261:Parasitic Sensitivity Tests / Q000379:methods; D011817:Rabbits; D013020:South America; D013696:Temperature; D013997:Time Factors; D006113:United Kingdom; D015053:Zygote / Q000187:drug effects* / Q000502:physiology
chemical_list: D000871:Anthelmintics; D015766:Albendazole