scholarly journals Anthelmintic Resistance and Its Mechanism: A Review

2021 ◽  
Vol Volume 14 ◽  
pp. 5403-5410
Author(s):  
Workye Fissiha ◽  
Mebrie Zemene Kinde
Author(s):  
Noorzaid Muhamad ◽  
Syahirah Sazeli ◽  
Resni Mona ◽  
Jannathul Firdous

The anthelmintic resistance has limited the control of gastrointestinal nematodes of small ruminants and thus has awakened interest in the study of plants extract as a source of anthelmintics. These experiments were carried out to evaluate the in vitro efficacy of Jatrophacurcas latex extract against Haemonchuscontortus larval motility. To evaluate the larvicidal activity, H.contortus L3 were incubated with the extracts with varying concentration of 5 mg/mL, 10 mg/mL, 15 mg/mL and 20 mg/mL at 27°C for 48, 72 and 96 hrs. The results were subjected to the Kruskal-Wallis test (P less than 0.05). The extracts showed dose-dependent larvicidal effects. These results suggest that J.curcas can be used to control gastrointestinal nematodes of small ruminants.


2019 ◽  
Vol 65 (1) ◽  
pp. 118-127
Author(s):  
Fernanda Ramos ◽  
Camila Balconi Marques ◽  
Caroline Zamperete Reginato ◽  
Patricia Bräunig ◽  
Vanessa Osmari ◽  
...  

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 335-335
Author(s):  
Alexa C Johnson ◽  
Amy S Biddle

Abstract Arbitrary administration of anthelmintics to control equine gastrointestinal worms has led to increased resistance to the three broad-spectrum drug classes; benzimidazoles, tetrahydropyrimidines, and macrocyclic lactones. With little promise of new drug classes to target cyathostomins being introduced to the market in the near future, anthelmintic drugs must be administered judiciously to prevent complete anthelmintic parasite resistance. The objective of this study is to determine the reemergence rate of cyathostomins following three commercial horse dewormers during summer. Nine horses housed at two locations were enrolled to the study and was repeated June–September through 2017–2019. Horses were removed from the study if sequencing failed due to low egg recovery for more than 50% of the timepoints. Ivermectin (macrocyclic lactones; n = 6), Moxidectin (macrocyclic lactones; n = 8) and Strongid (pyrantel pamoate; n = 8) were administered to horses and fecal samples were collected every 14d for 98d. Samples were tested using fecal egg counts with a modified McMaster technique and 18S rRNA profiling of the V5.8 and ITS1 regions. Sequences were clustered and taxonomy was assigned against a custom NCBI Blast+ database with the aligned sequences of 19 cyathostomins. Data were analyzed using presence/absence methods in R studio. Treatment and Day significantly impacted the average number of species present (P < 0.001). Moxidectin had the lowest number of species present followed by Strongid then Ivermectin (7.14, 10.17, 11.09, respectively). Equine shedder status had no effect on the average number of species present (P > 0.05). Six species, CO. labiatus, CS. catinatum, CY. auriculatus, CY. elongatus, CT. goldi and CT. longibursatus, showed resistance to the three treatments (P > 0.05). Moxidectin was the most effective at eradicating cyathostomins infestations (P < 0.05). Identifying resistance patterns at the species level will enable mechanistic molecular approaches to determine anthelmintic resistance in cyathostomins.


Author(s):  
Livio M. Costa-Junior ◽  
Umer N. Chaudhry ◽  
Philip J. Skuce ◽  
Seamus Stack ◽  
Neil D. Sargison

AbstractDevelopment of sustainable gastrointestinal nematode (GIN) control strategies depends on the ability to identify the frequencies of drug-susceptible and resistant genotypes in GIN populations arising from management practices undertaken on individual farms. Resistance to BZ drugs in GINs has been shown to be conferred by the presence of defined SNPs in the isotype 1 β-tubulin locus. Loop-mediated isothermal amplification (LAMP) assays are amenable to use on a range of DNA templates and are potentially adaptable to use in practical, cost-effective, pen-side diagnostic platforms that are needed to detect anthelmintic resistance in the field. In this study, we designed primers and examined LAMP assays to detect each of the three major isotype 1 β-tubulin SNPs conferring genetic susceptibility to BZ drugs. We used artificial pools of synthetic DNA, containing different proportions of susceptible and resistant SNPs to determine reproducibility of the assays. We demonstrated the detection of each of the isotype 1 β-tubulin SNPs conferring susceptibility to BZ drugs using the optimal LAMP assay. Isotype 1 β-tubulin SNP typing was effective in detecting BZ susceptibility, but the accuracy was reduced in samples with less than 60 % susceptible DNA. Our results show the potential for LAMP SNP typing to detect genetic susceptibility or resistance to anthelmintic drugs in livestock GINs, and some of the limitations in our approach that will need to be overcome in order to evaluate this assay using field samples.


2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Cynthia Machín ◽  
Yolanda Corripio-Miyar ◽  
Julia N. Hernández ◽  
Tara Pérez-Hernández ◽  
Adam D. Hayward ◽  
...  

AbstractDue to increased anthelmintic resistance, complementary methods to drugs are necessary to control gastrointestinal nematodes (GIN). Vaccines are an environmentally-friendly and promising option. In a previous study, a Teladorsagia circumcincta recombinant sub-unit vaccine was administered to two sheep breeds with different levels of resistance against GIN. In the susceptible Canaria Sheep (CS) breed, vaccinates harboured smaller worms with fewer eggs in utero than the control group. Here, we extend this work, by investigating the cellular and humoral immune responses of these two sheep breeds following vaccination and experimental infection with T. circumcincta. In the vaccinated CS group, negative associations between antigen-specific IgA, IgG2 and Globule Leukocytes (GLs) with several parasitological parameters were established as well as a higher CD4+/CD8+ ratio than in control CS animals, suggesting a key role in the protection induced by the vaccine. In the more resistant Canaria Hair Breed (CHB) sheep the vaccine did not significantly impact on the parasitological parameters studied and none of these humoral associations were observed in vaccinated CHB lambs, although CHB had higher proportions of CD4+ and CD8+ T cells within the abomasal lymph nodes, suggesting higher mucosal T cell activation. Each of the component proteins in the vaccine induced an increase in immunoglobulin levels in vaccinated groups of each breed. However, levels of immunoglobulins to only three of the antigens (Tci-MEP-1, Tci-SAA-1, Tci-ASP-1) were negatively correlated with parasitological parameters in the CS breed and they may be, at least partially, responsible for the protective effect of the vaccine in this breed. These data could be useful for improving the current vaccine prototype.


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