Observations on the fumarate reductase system in Haemonchus contortus and their relevance to anthelmintic resistance and to strain variations of energy metabolism

1983 ◽  
Vol 7 (4) ◽  
pp. 281-292 ◽  
Author(s):  
Chris Bryant ◽  
Eva-Maria Bennet
Keyword(s):  
Energy Metabolism ◽  
Haemonchus Contortus ◽  
Anthelmintic Resistance ◽  
Fumarate Reductase

Effect of Jatropha curcas Latex on L3 Haemonchus contortus Larval Motility

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Noorzaid Muhamad ◽  
Syahirah Sazeli ◽  
Resni Mona ◽  
Jannathul Firdous
Keyword(s):  
Larvicidal Activity ◽  
Jatropha Curcas ◽  
Haemonchus Contortus ◽  
Anthelmintic Resistance ◽  
Small Ruminants ◽  
Gastrointestinal Nematodes ◽  
Dose Dependent ◽  
Plants Extract

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.

scholarly journals Frequency of benzimidazole resistance inHaemonchus contortus populations isolated from buffalo, goat and sheep herds

2013 ◽  
Vol 22 (4) ◽  
pp. 548-553 ◽  
Author(s):  
Ronaldo Luiz Nunes ◽  
Livia Loiola dos Santos ◽  
Eduardo Bastianetto ◽  
Denise Aparecida Andrade de Oliveira ◽  
Bruno Santos Alves Figueiredo Brasil
Keyword(s):  
Haemonchus Contortus ◽  
Significant Variation ◽  
Genetic Basis ◽  
Anthelmintic Resistance ◽  
Allelic Frequency ◽  
Molecular Diagnostic ◽  
Economic Losses ◽  
Diagnostic Tools ◽  
Ruminant Species ◽  
Benzimidazole Resistance

Anthelmintic resistance is an increasing problem that threatens livestock production worldwide. Understanding of the genetic basis of benzimidazole resistance recently allowed the development of promising molecular diagnostic tools. In this study, isolates of Haemonchus contortus obtained from goats, sheep and buffaloes raised in Brazil were screened for presence of the polymorphism Phe200Tyr in the β-tubulin 1 gene, which confers resistance to benzimidazole. The allelic frequency of the mutation conferring resistance ranged from 7% to 43%, and indicated that resistance to benzimidazole could be found in nematodes isolated from all the ruminant species surveyed. Although significant variation in the frequency of the F200Y mutation was observed between different herds or host species, no significant variation could be found in populations isolated from animals within the same herd. These findings suggest that screening of samples from a few animals has the potential to provide information about the benzimidazole resistance status of the entire herd, which would enable a considerable reduction in the costs of diagnosis for the producer. Molecular diagnosis has practical advantages, since it can guide the choice of anthelmintic drug that will be used, before its application in the herd, thus reducing the economic losses driven by anthelmintic resistance.

scholarly journals 26 Copper oxide wire particles to complement control of gastrointestinal nematodes with levamisole and/or albendazole in lambs

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 73-73
Author(s):  
Joan M Burke ◽  
James E Miller ◽  
Mohan Acharya ◽  
Erin Wood
Keyword(s):  
Copper Oxide ◽  
Haemonchus Contortus ◽  
Repeated Measures ◽  
Mixed Model ◽  
Anthelmintic Resistance ◽  
Gastrointestinal Nematodes ◽  
High Prevalence ◽  
The Mean ◽  
Further Development

Abstract Due to high prevalence of anthelmintic resistance (AR), complementary approaches to anthelmintic use to control gastrointestinal nematodes (GIN) in sheep are necessary. Copper oxide wire particles (COWP) are effective against Haemonchus contortus but not other GIN, and FAMACHA aids to minimize further development of AR. The objective was to determine the efficacy of COWP alone or in combination with levamisole, albendazole, or a 3-way combination to control GIN known to have AR to these anthelmintics. Naturally infected Katahdin lambs were selectively dewormed based on FAMACHA© and/or packed cell volume (PCV). If FAMACHA© scores were 3, 4, or 5, lambs received 1 g COWP alone (n = 120), COWP and levamisole (n = 47) or albendazole (n = 6), or a 3-way combination (n = 10), respectively. Untreated lambs were included (CON; n = 31). Feces and blood were collected on days 0 (day of deworming) and 14 for determination of fecal egg counts (FEC) and FEC reduction (FECRED) and PCV. Data were analyzed using repeated measures in a mixed model. The mean FECRED was greater for the combination of levamisole and COWP than COWP alone (P < 0.001). In a mixed GIN population, COWP in combination with levamisole increased the efficacy of FECRED of H. contortus and other GIN genera present, offering greater GIN management in the presence of resistance to these anthelmintics.

scholarly journals Comparison of two in vitro methods for the detection of ivermectin resistance in Haemonchus contortus in sheep

2016 ◽  
Vol 53 (2) ◽  
pp. 120-125 ◽  
Author(s):  
M. Urda Dolinská ◽  
A. Königová ◽  
M. Babják ◽  
M. Várady
Keyword(s):  
Drug Resistance ◽  
Haemonchus Contortus ◽  
Anthelmintic Resistance ◽  
Economic Losses ◽  
Parasitic Nematodes ◽  
Migration Inhibition ◽  
In Vitro Methods ◽  
Parasitic Helminths

SummaryGastrointestinal parasitic nematodes in sheep cause severe economic losses. Anthelmintics are the most commonly used drugs for prophylaxis and therapy against parasitic helminths. The problem of drug resistance has developed for all commercially available anthelmintics in several genera and classes of helminths. In vitro and in vivo tests are used to detect anthelmintic resistance. Two in vitro methods (larval migration inhibition test and micromotility test) for the detection of ivermectin (IVM) resistance were compared using IVM-resistant and IVM-susceptible isolates of Haemonchus contortus. The degree of resistance for each test was expressed as a resistance factor (RF). The micromotility test was more sensitive for quantitatively measuring the degree of resistance between susceptible and resistant isolates. The RFs for this test for IVM and eprinomectin ranged from 1.00 to 108.05 and from 3.87 to 32.32, respectively.

scholarly journals Complementary Approaches to Understand Anthelmintic Resistance Using Free-Living and Parasitic Nematodes

2020 ◽  
Author(s):  
Janneke Wit ◽  
Clayton Dilks ◽  
Erik Andersen
Keyword(s):  
Haemonchus Contortus ◽  
Parasitic Nematode ◽  
Anthelmintic Resistance ◽  
Nematode Species ◽  
The Other ◽  
Parasitic Nematodes ◽  
Mechanisms Of Resistance ◽  
Free Living ◽  
Sustained Efficacy ◽  
Modes Of Action

Anthelmintic drugs are the major line of defense against parasitic nematode infections, but the arsenal is limited and resistance threatens sustained efficacy of the available drugs. Discoveries of the modes of action of these drugs and mechanisms of resistance have predominantly come from studies of a related non-parasitic nematode species, Caenorhabditis elegans, and the parasitic nematode Haemonchus contortus. Here, we discuss how our understanding of anthelmintic resistance and modes of action came from the interplay of results from each of these species. We argue that this “cycle of discovery”, where results from one species inform the design of experiments in the other, can use the complementary strengths of both to understand anthelmintic modes of action and mechanisms of resistance.

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