title: Identification of a field isolate of Fasciola hepatica resistant to albendazole and susceptible to triclabendazole.
abstract: The experiments described here were designed to characterize the status of susceptibility/resistance to albendazole (ABZ) and triclabendazole (TCBZ) of a Fasciola hepatica isolate (named CEDIVE isolate) recovered from infected sheep (Gualeguay, Argentina) and maintained under laboratory conditions. Two separate clinical efficacy experiments were performed on sheep artificially infected with the CEDIVE isolate. Experiment 1: sheep were randomly distributed either in an untreated control group or in an ABZ (7.5 mg/kg) treated group (n=4 each). Additionally, the systemic exposure of ABZ metabolites was assessed in those ABZ-treated infected animals. In Experiment 2, an untreated control group and a TCBZ (10 mg/kg) treated group was included (n=4 each). The fluckicidal efficacy of ABZ and TCBZ was assessed by the comparison of the number of flukes recovered from untreated and treated sheep at 15 days post-treatment. The efficacy against the CEDIVE isolate of F. hepatica was 29% (ABZ) and 100% (TCBZ). The plasma drug exposure (expressed as AUC and C(max)) observed in the ABZ treated animals (Experiment 1) was in agreement with data obtained in the previous studies, which indicate that the low ABZ efficacy was not related to the quality of the pharmaceutical product and/or to a low systemic availability of the active drug/metabolite. The results reported here clearly show that the CEDIVE isolate of F. hepatica behaves as resistant to ABZ and susceptible to TCBZ.
authors.affiliation: Centro de Diagnóstico e Investigaciones Veterinarias (CEDIVE), Facultad de Ciencias Veterinarias, Universidad Nacional de la Plata, 7130 Chascomús, Argentina.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Sanabria
authors.forename: Laura
authors.initials: L
authors.lastname: Ceballos
authors.forename: Laura
authors.initials: L
authors.lastname: Moreno
authors.forename: Jorge
authors.initials: J
authors.lastname: Romero
authors.forename: Carlos
authors.initials: C
authors.lastname: Lanusse
authors.forename: Luis
authors.initials: L
authors.lastname: Alvarez
mesh_terms: D015766:Albendazole / Q000494:pharmacology*; D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology; D019540:Area Under Curve; D001118:Argentina / Q000453:epidemiology; D001562:Benzimidazoles / Q000494:pharmacology*; D004351:Drug Resistance; D005210:Fasciola hepatica / Q000187:drug effects*; D005211:Fascioliasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D006207:Half-Life; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000469:parasitology*; D000077682:Triclabendazole
chemical_list: D000871:Anthelmintics; D001562:Benzimidazoles; D000077682:Triclabendazole; D015766:Albendazole