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.