A real-time PCR approach to identify anthelmintic-resistant nematodes in sheep farms

Abstract

Resistance to fenbendazole, ivermectin, and moxidectin was explored by a fecal egg count reduction test in four meat sheep flocks in southwestern France where anthelmintic resistance was suspected. The FECR test results of the present study confirmed the presence of benzimidazole resistance in three out of the four farms and the presence of ivermectin resistance in one flock. In addition, a suspicion of moxidectin resistance was shown in this latter farm. Both conventional morphological and molecular identifications were performed on larval cultures before and after the treatment in the studied farms. A high positive correlation was found between the number of larvae counted under binocular microscope and the number of larvae estimated by the qPCR analysis (R 2 = 0.88) and a high Cohen's Kappa value (0.91) in the detection of strongylid larvae in larval cultures. According to qPCR results, Trichostrongylus species demonstrated high levels of BZ resistance and Teladorsagia circumcincta was involved in the IVM resistance in one farm. The molecular procedures used in this study have the potential to be beneficial for anthelmintic resistance surveillance in sheep industry.

PCR-RFLP screening of polymorphisms associated with benzimidazole resistance in Necator americanus and Ascaris lumbricoides from different geographical regions in Brazil

“…A wide range of molecular techniques may be employed for the analysis of these SNPs. Methodologies based on qPCR and sequencing have been described for analysis of SNPs in the beta-tubulin gene [ 19 , 21 ]. Rashwan and colleagues [ 8 ] developed a genotyping assay of SNPs on the N .…”

The use of ITS-2 rDNA nemabiome metabarcoding to enhance anthelmintic resistance diagnosis and surveillance of ovine gastrointestinal nematodes

“…Consequently, a simple percentage strongyle egg count reduction has limited sensitivity and accuracy for detection of anthelmintic resistance when the parasite populations consists of a mixture of resistant and susceptible species. The methods available to identify nematode species include coproculture combined with L3 morphology and morphometry, conventional PCR, real-time PCR, droplet digital PCR ( Elmahalawy et al, 2018 ) and pyrosequencing ( Álvarez-Sánchez et al, 2005 ; Roeber et al, 2011 , 2017 ; Milhes et al, 2017 ). Each of these approaches have different limitations.…”

High Endemicity of Soil-Transmitted Helminths in a Population Frequently Exposed to Albendazole but No Evidence of Antiparasitic Resistance

“…Although this limited efficacy may be due to several factors, concerns have been raised that genetic resistance to BZ may be involved in the prevalence of T. trichiura . These concerns are founded on unambiguous biological evidence and clinical experience from the field of veterinary medicine, [14,15,16] where three amino acid substitutions in codons 167, 198, and 200 of the β-tubulin gene of Haemonchus contortus have been associated with BZ resistance [17,18,19].…”