ArticleParasites & vectors2020
Teladorsagia circumcincta beta tubulin: the presence of the E198L polymorphism on its own is associated with benzimidazole resistance.
Article in Parasites & vectors, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
15 citing papers in PubMed, 37 citations in OpenAlex.
- Evaluating beta-tubulin variants as predictors of benzimidazole resistance across Caenorhabditis nematodes.PLoS pathogens · 2026Article
- The occurrence of cross-host species soil-transmitted helminth infections in humans and domestic/livestock animals: A systematic review.PLOS global public health · 2025Article
- Sustainable worm control in ruminants in Europe: current perspectives.Animal frontiers : the review magazine of animal agriculture · 2024Article
- Secretory IgA as Biomarker for Gastrointestinal Nematodes Natural Infection in Different Breed Sheep.Animals : an open access journal from MDPI · 2023Article
- Variation in allele frequencies in benzimidazole resistant and susceptible isolates of Haemonchus contortus during patent infection in lambs.Scientific reports · 2023Article
- Revealing novelFrontiers in veterinary science · 2023Article
- Microbial community in resistant and susceptible Churra sheep infected by Teladorsagia circumcincta.Scientific reports · 2022Article
- Article
- Benzimidazole and aminoalcohol derivatives show in vitro anthelmintic activity against Trichuris muris and Heligmosomoides polygyrus.Parasites & vectors · 2022Article
- Absence of Polymorphisms in Codons 167, 198 and 200 of All Seven β-Tubulin Isotypes of Benzimidazole Susceptible and ResistantPathogens (Basel, Switzerland) · 2022Article
- Phenotypic and genotypic analysis of benzimidazole resistance in reciprocal genetic crosses of Haemonchus contortus.International journal for parasitology. Drugs and drug resistance · 2022Article
- Occurrence of Strongylid Nematode Parasites on Horse Farms in Berlin and Brandenburg, Germany, With High Seroprevalence ofFrontiers in veterinary science · 2022Article
- Improving stool sample processing and pyrosequencing for quantifying benzimidazole resistance alleles in Trichuris trichiura and Necator americanus pooled eggs.Parasites & vectors · 2021Article
- Comparative evaluation of different molecular methods for DNA extraction from individual Teladorsagia circumcincta nematodes.BMC biotechnology · 2021Article
- Susceptible trichostrongyloid species mask presence of benzimidazole-resistant Haemonchus contortus in cattle.Parasites & vectors · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
9 authors at 4 institutions in 2 countries.
Funding
Abstract
backgroundBenzimidazole resistance is associated with isotype-1 β-tubulin gene F200Y, E198A and F167Y SNPs. In this study, the recently described polymorphism E198L was reported and analysed in Teladorsagia circumcincta.
methodsThe benzimidazole phenotypic resistance was measured by the faecal egg count reduction test (FECRT) and the egg hatch test (EHT) using a discriminating dose (DD) in 39 sheep flocks. Around 1000 larvae collected before and after treatment were used for DNA extraction. The resistant species identified in all flocks was T. circumcincta. The resistance alleles frequencies were measured for F200Y and E198A. A 371-bp fragment of the isotype-1 β-tubulin gene was analysed, including the three codons of interest, and a new pyrosequencing assay was designed for testing E198L.
resultsThe percentage of resistant flocks was 35% by FECRT or 26% by EHT; however, F200Y and E198A SNPs were absent in T. circumcincta. The amplification of a 371-bp fragment confirmed the absence of F167Y and F200Y in 6 resistant flocks. Regarding codon 198, all samples after treatment carried a leucine (CTA). A pyrosequencing assay analysed the allele frequencies for the first two bases at codon 198 independently, G/C and A/T. The correlation between C and T frequencies was almost 1 (r = 0.929, P < 0.0001) and the mean value of both was calculated to measure the leucine frequency; this value ranged between 10.4-80.7% before treatment, and 82.3-92.8% after treatment. High and similar correlations were reported between the genotypic variables (C frequency, T frequency or mean of both frequencies) and phenotypic resistance (r > 0.720, P < 0.0001), although negatively associated with the FECRT and positively with the EHT. According to multivariate linear regression analysis, the T frequency was the most significant variable influencing the phenotypic resistance (FECRT or EHT; P < 0.0001). In the EHT, 67.1% of the phenotypic variability is associated with the T frequency but in the FECRT only 33.4%; therefore, the EHT using a DD seems to detect the genotypic resistance more accurately than the FECRT.
conclusionsThe E198L polymorphism can confer BZ resistance on its own in T. circumcincta.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.