Frequency of Resistance to Benzimidazoles of Haemonchus contortus Helminths from Dairy Sheep, Goats, Cattle and Buffaloes in Greece.

Konstantinos Arsenopoulos,George Fthenakis,Elias Papadopoulos,Styliani Minoudi,Alexandros Triantafyllidis,Angeliki Katsafadou,Daphne Lianou,Isaia Symeonidou

doi:10.3390/pathogens9050347

Konstantinos Arsenopoulos, George Fthenakis + Show 6 more

Open Access

https://doi.org/10.3390/pathogens9050347

Copy DOI

Abstract

The study investigated the presence of resistance to benzimidazoles in Haemonchus contortus helminths from ruminant species in Greece through the detection of the Phe/Tyr polymorphism in the amino acid at position 200 of the β-tubulin protein. In total, 288 adult female H. contortus helminths collected from the abomasum of various ruminant animals in Greece were tested. Of these, 96 were collected from sheep, 96 from goats, 48 from cattle, and 48 from buffaloes. The frequencies of the homozygous and heterozygous resistant genotypes at the position 200 of the β-tubulin gene of helminths recovered from sheep were 96.9% and 3.1%, respectively. The frequencies of the homozygous and heterozygous resistant genotypes, respectively, were 100.0% and 0.0% in helminths from goats, 25.0% and 75.0% in helminths from cattle and 8.3% and 91.7% in helminths from buffaloes. In all parasitic populations, no homozygous susceptible genotypes were detected. The present study highlighted, for the first time, the emergence of benzimidazole-resistant H. contortus in goats, cattle, and buffaloes in Greece, using an allele-specific PCR. It is postulated that benzimidazole-resistant alleles were transferred from sheep or goats to cattle and buffaloes at the commonly grazing pastures in Greece.

Highlights

Gastrointestinal nematodes (GIN) lead to a significant decrease of productivity in grazing ruminants worldwide [1,2,3]
Of the 288 H. contortus helminths evaluated during the study, 205 (71.2%) were found to be homozygous benzimidazole-resistant, and 83 (28.8%) were found to be heterozygous benzimidazole-resistant
Differences in frequencies between helminths recovered from sheep or goats and cattle or buffaloes were always significant (P < 0.001), whilst differences in frequencies between helminths recovered from sheep and goats and between cattle and buffaloes were not (P > 0.052)

Summary

Introduction

Gastrointestinal nematodes (GIN) lead to a significant decrease of productivity in grazing ruminants worldwide [1,2,3]. E.g., Haemonchus spp., Teladorsagia circumcincta and Trichostrongylus spp. lead to severe constraints in ruminant production, as the respective infections cause a reduction in milk and meat production, incur veterinary expenses, and may lead to the death of the affected animals during severe infections [4,5,6]. Among GIN, helminths of the genus Haemonchus are considered (along with Teladorsagia spp.) to be the most pathogenic parasites of ruminants due to their blood feeding activity [7,8]. H. contortus infects predominantly grazing sheep and goats, while H. placei has been detected mainly in large ruminants, e.g., cattle and buffaloes.

Methods

Results

Conclusion