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Research article - Peer-reviewed, 2020

Assessment of the F200Y mutation frequency in the beta tubulin gene of Haemonchus contortus following the exposure to a discriminating concentration of thiabendazole in the egg hatch test

Baltrusis, Paulius; Komaromyova, Michaela; Varady, Marian; von Samson-Himmelstjerna, Georg; Hoglund, Johan


The ruminant livestock production sector is under threat due to the infections with gastrointestinal nematode parasites and the subsequent development of anthelmintic resistance. One of most common and pathogenic species in small ruminants is Haemonchus contortus. The ability to control the infections with this and other gastrointestinal nematodes relies heavily on the use of anthelmintic drugs. Although resistance to all major classes of anthelmintics has been shown in H. contortus, the precise mechanism of resistance acquisition is only known for benzimidazoles. F200Y (TAC) is a common point mutation in the isotype 1 beta tubulin gene which is associated with an effective increase in the resistance towards benzimidazole drugs. Here, we show the utility of using this mutation as a marker in a droplet digital PCR assay to track how two H. contortus laboratory strains, characterized by different resistance levels, change with respect to this mutation, when subjected to increasing concentrations of thiabendazole. Additionally, we wanted to investigate whether exposure to a discriminating dose of thiabendazole in the egg hatch test resulted in the death of all H. contortus eggs with a susceptible genotype. We found the MHco5 strain to maintain an overall higher frequency of the F200Y mutation (80-100%) over all drug concentrations, whilst a steady, gradual increase from around 30%-60% was observed in the case of the MHco4 strain. This is further supported by the dose-response curves, displaying a much higher tolerance of the MHco5 strain (LD50 = 0.38 mu g/ml) in comparison to the MHco4 strain (LD50 = 0.07 mu g/ml) to the effects of thiabendazole. All things considered, we show that the F200Y mutation is still a viable and reliable marker for the detection and surveillance of benzimidazole drug resistance in H. contortus in Europe.


Droplet digital PCR; Haemonchus contortus; beta tubulin; F200Y; Anthelmintic resistance; Benzimidazole

Published in

Experimental Parasitology
2020, volume: 217, article number: 107957

Authors' information

Baltrusis, Paulius
Swedish University of Agricultural Sciences, Department of Biomedical Science and Veterinary Public Health
Komaromyova, Michaela
Slovak Academy of Sciences
Varady, Marian
Slovak Academy of Sciences
von Samson-Himmelstjerna, Georg
Free University of Berlin

Sustainable Development Goals

SDG3 Good health and wellbeing

UKÄ Subject classification

Clinical Science

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