Screening of benzimidazole resistance in cattle gastrointestinal nematodes using faecal egg count reduction test, nemabiome metabarcoding, and β-tubulin sequencing

CANTON C.; MATÉ M. L.; REDMAN ELIZABETH; DOMINGUEZ P.; MORIONES L.; BALLENT M.; LANUSSE C.; ALVAREZ L.; GILLEARD J; LIRON JP.

Chennai

Congreso; 29th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP); 2023

WAAVP

Methods for anthelmintic resistance (AR) detection most currently used for diagnosis are based on phenotype, so resistance typically only being detected once its development is already high. Benzimidazole (BZ) resistance in gastrointestinal (GI) nematodes was evaluated in beef cattle using a combination of faecal egg count reduction test (FECRT), nemabiome metabarcoding and deep amplicon sequencing. BZs efficacies were evaluated using the in vivo FECRT on 8 commercial cattle farms from Argentina. Calves naturally infected with GI nematodes resistant to ivermectin were treated with ricobendazole, albendazole or oxfendazole. ITS-2 and β-tubulin deep amplicon sequencing were applied to L3 obtained from pooled coprocultures pre- and post-treatment to quantify the species composition and determine the frequency of the known BZ resistance associated SNPs for the GI nematodes species. BZ resistance defined by overall FECR 90% on the field, demonstrating the potential of β-tubulin amplicon sequencing to screen for the emergence of AR mutations, encouraging parasite control strategies to minimize the development and spread of BZ-resistance.