Absence of mutations associated with resistance to benzimidazole in the beta-tubulin gene of ascaris suum

Abstract

Introduction: Benzimidazoles are commonly used for the control of veterinary nematodes. Resistance to benzimidazoles has been associated with three single nucleotide polymorphisms in the β-tubulin gene of common nematodes. However, these mutations are infrequent in the genus Ascaris spp. Methods: In order to determine mutations associated with benzimidazole resistance in Ascaris suum, worms were collected from slaughtered pigs and a partial region of the β-tubulin gene was sequenced. Results: All parasites showed the wildtype genotype for codons 167, 198, and 200 of the β-tubulin gene. Conclusions: This is the first report of genetic sequences associated with benzimidazole resistance in A. suum.