scholarly journals Does the in vitro egg hatch test predict the failure of benzimidazole treatment in Haemonchus contortus?

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 62
Author(s):  
Michal Babják ◽  
Alžbeta Königová ◽  
Michaela Urda Dolinská ◽  
Tomas Kupčinskas ◽  
Jaroslav Vadlejch ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Gastrointestinal Parasites ◽  
Resistant Isolate ◽  
Egg Hatch ◽  
Larval Stages ◽  
Tubulin Isotype ◽  
Faecal Egg Count ◽  
Egg Hatch Test

Considerable research has been directed towards optimising in vitro tests that can diagnose resistance in pre-parasitic stages of parasites. The objective of this study was to compare the in vivo faecal egg count reduction test (FECRT), the in vitro egg hatch test (EHT), and the molecular determination of the frequency of a codon 200 allele of β-tubulin isotype 1 associated with benzimidazole resistance in larval stages of Haemonchus contortus obtained from infected goats. Animals were infected with composite infective doses representing 10, 20, 30, 40, 60, and 80% resistant alleles. Faecal samples for the EHT were collected on 28, 33, and 35 days post-infection. The results of the in vivo FECRT indicated that albendazole treatment reduced infections consisting of composite doses of 10, 20, 30, 40, 60, and 80% larvae of the resistant isolate by 91.3, 78.0, 63.3, 48.4, 36.5, and 41.4%, respectively. The drug concentration at which 50% of the eggs were prevented from developing hatching larvae (ED50) in the in vitro EHT varied from 0.09 ± 0.01 to 15.63 ± 12.10 μg/mL thiabendazole. The results of the in vitro EHT indicated that the test could estimate in vivo resistance well. The EHT could thus accurately estimate the in vivo efficacy of the drug and percentage of the resistance allele in the population using hatching parameters in delineation doses. This finding was also supported by comparing the FECRT data to the hatching percentages in the EHT on 30 goat farms in Slovakia with natural mixed infections of gastrointestinal parasites.

scholarly journals Comparative anthelmintic efficacy of Arundo donax, Areca catechu, and Ferula assa-foetida against Haemonchus contortus

2021 ◽  
Vol 30 (2) ◽  
Author(s):  
Syed Nadeem Badar ◽  
Zafar Iqbal ◽  
Muhammad Sohail Sajid ◽  
Hafiz Muhammad Rizwan ◽  
Muhammad Shareef ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Haemonchus Contortus ◽  
Anthelmintic Activity ◽  
Parasitic Nematodes ◽  
Egg Hatch ◽  
Faecal Egg Count ◽  
Areca Catechu ◽  
Better Than

Abstract In the present study, anthelmintic activities of Arundo (A.) donax L., Areca (Ar.) catechu L., and Ferula (F.) assa-foetida L. were determined. Leaves of A. donax L., latex of F. assa-foetida L. and seeds of Ar. catechu L. in different solvent fractions were subjected to in vitro (egg hatch assay; EHA, and adult motility assay; AMA) and in vivo (faecal egg count reduction test; FECRT) tests of anthelmintic activity using Haemonchus contortus model. In the AMA, crude aqueous methanol extracts (CAME) and ethyl acetate fractions of F. assa-foetida at 10 hr post-treatment showed maximum mortality of H. contortus at 12.5-50 mg mL-1. In the EHA, CAME of F. assa-foetida was identified as a potent ovicide based on its low LC50 (16.9 µg mL-1), followed in order by Ar. catechu and A. donax. Results from the FECRT also showed the extract of F. assa-foetida L. to be more effective than those of Ar. catechu L. and A. donax L., against the gastrointestinal parasitic nematodes. Chloroform and ethyl acetate fractions showed better anthelmintic activities against the adult worms in vitro, while CAME of these plants were better than their crude powders in vivo. It is recommended to document and investigate indigenous knowledge of possible medicinal plants to plan scientific trials that may justify their endorsement.

Effect of selection pressure for thiabendazole resistance on fitness of Haemonchus contortus in sheep

Parasitology ◽  
1990 ◽  
Vol 100 (2) ◽  
pp. 327-335 ◽  
Author(s):  
N. Maingi ◽  
M. E. Scott ◽  
R. K. Prichard
Keyword(s):  
Haemonchus Contortus ◽  
Selection Pressure ◽  
Egg Hatch ◽  
Worm Recovery ◽  
Per Capita ◽  
Egg Hatch Assay ◽  
Severe Pathology ◽  
Larval Establishment

SUMMARYA Strain ofHaemonchus contortusshowing moderate levels of resistance to thiabendazole (TBZ) (egg hatch assay LC50 2.1 μM) was subjected, in alternating sequence, to 5 in vitro and 4 in vivo selections with TBZ. This resulted in a significant increase in resistance (egg hatch assay LC50 2.8 μM). The isolates obtained after each combined in vitro and in vivo selection were compared in terms of egg hatch assay, establishment, net egg output, per capita egg output and degree of pathology caused in infected hosts. The increase in resistance was accompanied by a significant increase in larval establishment sheep (22 %) and was associated with more severe pathology, higher egg count and worm recovery 3 months post- infection.

Comparative in vitro efficacy of kefir produced from camel, goat, ewe and cow milk on Haemonchus contortus

2018 ◽  
Vol 93 (04) ◽  
pp. 440-446
Author(s):  
D. Alimi ◽  
M. Rekik ◽  
H. Akkari
Keyword(s):  
Haemonchus Contortus ◽  
Therapeutic Potential ◽  
Small Ruminants ◽  
Gastrointestinal Parasites ◽  
Camel Milk ◽  
Alternative Methods ◽  
Cow Milk ◽  
Egg Hatching

AbstractOne of the great challenges of veterinary parasitology is the search for alternative methods for controlling gastrointestinal parasites in small ruminants. Milk kefir is a traditional source of probiotic, with great therapeutic potential. The objective of this study was to investigate the anthelmintic effects of kefir on the abomasal nematode Haemonchus contortus from sheep. The study used camel, goat, ewe and cow milk as a starting material, to produce camel, goat, cow and ewe milk kefir. All kefirs showed a significant concentration-dependent effect on H. contortus egg hatching at all tested concentrations. The highest inhibition (100%) of eggs was observed with camel milk kefir at a concentration 0.125 mg/ml. In relation to the effect of kefirs on the survival of adult parasites, all kefirs induced concentration-dependent mortality in adults, with variable results. The complete mortality (100%) of adults of H. contortus occurred at concentrations in the range 0.25–2 mg/ml. The highest inhibition of motility (100%) of worms was observed after 8 h post exposure with camel milk kefir at 0.25 mg/ml. These findings indicate that kefir can be considered a potential tool to control haemonchosis in sheep. Further investigations are needed to assess the active molecules in kefir responsible for its anthelmintic properties and to investigate similar in vivo effects.

Anthelmintic evaluation of Cucurbita pepo againstgastrointestinal nematodes of sheep

2017 ◽  
Author(s):  
Ambalathaduvar Meenakshisundaram ◽  
Tirunelveli Jayagopal Harikrishnan ◽  
Thavasi Anna
Keyword(s):  
Larval Development ◽  
Anthelmintic Activity ◽  
Gastrointestinal Nematodes ◽  
Migration Inhibition ◽  
Egg Hatch ◽  
Larval Migration ◽  
Faecal Egg Count ◽  
Ethanolic Extracts

The study was aimed at to investigate the anthelmintic efficacy of aqueous and ethanolic extracts of Cucurbita pepo against gastrointestinal nematodes of sheep by scientifically validated in vitro and in vivo tests. In vitro anthelmintic activity was determined by egg hatch assay, larval migration inhibition assay and larval development assay against eggs and larvae of mixed gastrointestinal nematodes of sheep. The extracts which were found to be effective in in vitro assays were further evaluated by in vivo faecal egg count reduction test against mixed species of sheep gastrointestinal nematodes with 3 different doses (125, 250 and 500 mg kg-1). Haematological and serum parameters were estimated before and after treatment to determine the impact of plant extracts on health of the animal. Aqueous extract of C. pepo demonstrated significant inhibition of egg hatch at 40 and 80 mg/ml. The ED50 value of egg hatch inhibition was 3.51mg/ml. In larval migration inhibition assay, both aqueous and ethanolic extracts of C. pepo demonstrated inhibition of larval migration and the LM50 was 1.75 and 0.32 mg/ml respectively. However, in larval development assay, both aqueous and ethanolic extracts showed only marginal inhibition of larval development at all concentrations tested. In faecal egg count reduction test (FECRT), aqueous extracts of C. pepo at 500 mg/kg caused significant reduction in eggs per gram (96.61 per cent) the reduction being higher than the result obtained with albendazole, the positive control (93.25 per cent). There was a significant difference in EPG reduction between sheep treated with albendazole and C. pepo. Haematological and serum parameters were not affected in both the treated and untreated sheep indicating that the extracts did not cause toxic effects. Based on the results obtained in this study, the aqueous extract of C. pepo possesses anthelmintic activity and could offer an alternative source for the control of gastrointestinal nematodes of sheep.

scholarly journals Weak phenotypic reversion of ivermectin resistance in a field resistant isolate of Haemonchus contortus by verapamil

2011 ◽  
Vol 31 (9) ◽  
pp. 731-736 ◽  
Author(s):  
Fernando A. Borges ◽  
Julhiano B. Rossini ◽  
Patrícia P. Velludo ◽  
Carolina Buzzulini ◽  
Gustavo H. Costa ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Field Isolate ◽  
Resistant Isolate ◽  
High Concentration ◽  
Vitro Assay ◽  
Migration Assay ◽  
First Results ◽  
Phenotypic Reversion

Recent advances in anthelmintic resistant phenotype reversion by Pgp modulating drugs in ruminant nematodes indicate that this can be a useful tool to helminth control. The aim of the present study was to evaluate the efficacy of ivermectin (IVM) in combination with verapamil (VRP), in oil or water-based vehicle, against an IVM-resistant field isolate of Haemonchus contortus through a larval migration assay and experimental infection trial. In the in vitro assay was observed a phenotypic reversion of H. contortus resistance to ivermectin at a high concentration of VRP, increasing IVM efficacy from 53.1% to 94.3. In the in vivo trial, IVM + VRP demonstrated 36.02% efficacy compared to the 7.75% of IVM alone. The vehicle formulation showed no influence in efficacy. These are the first results demonstrating the effect of VRP as a partial IVM-resistance phenotype reverser in a field isolate of IVM-resistant H. contortus experimentally inoculated in sheep.

scholarly journals Benzimidazoles Pharmacodynamics in Equine Strongyles

2016 ◽  
Vol 73 (2) ◽  
pp. 360
Author(s):  
Laura Catana ◽  
Csongor Olah ◽  
Raul Catana ◽  
Mihai Cernea
Keyword(s):  
Larval Development ◽  
Treatment Protocol ◽  
Average Intensity ◽  
Egg Hatch ◽  
Maximum Value ◽  
Limited Effectiveness ◽  
Faecal Egg Count ◽  
Comparative Risk

Our research aimed to assess the effectiveness of four benzimidazoles: albendazole, fenbendazole, mebendazole and thiabendazole against equine strongyles. The tests were performed between March 2015 and May 2016, on samples collected from 20 horses and 8 donkeys living in Harghita County. In vivo, Faecal Egg Count Reduction Test (FECRT) was used to evaluate fenbendazole pharmacodynamics. In vitro, Egg hatch assay (EHA) and Larval development assay (LDA) were used to evaluate the effectiveness of albendazole, fenbendazole, mebendazole and thiabendazole. The predominance of small strongyle species was observed, mostly Cyathostomum type A. In the horse group, before treatment, the average intensity was 1595.5 EPG, the maximum value being 4000, and extensivity 55%. Tested again at 14 days after treatment, all samples were negative. In the donkey group, before treatment, the total number was 6550 EPG, intensity of 935.7 and extensivity of 87.5%. 14 days after treatment, the average intensity was 150 and the extensivity 50%. In the horse group, EHA proved the efficacy of fenbendazole (0.0192%), albendazole (0.3740%) and thiabendazole (11.62%) and a major risk of inducing adaptive phenomena for mebendazole (Y parameter 1009.92). In the donkey group, all benzimidazoles had limited effectiveness: thiabendazole (73.93%), mebendazole (87.51%), fenbendazole (94.05%), albendazole (111.67%). All benzimidazoles inhibited larval development. For all tested benzimidazoles, the resistance induction predictive comparative risk analysis highlighted the benefit of their use, provided that the treatment protocol allows sufficient contact time.

scholarly journals Piper aduncum against Haemonchus contortus isolates: cross resistance and the research of natural bioactive compounds

2016 ◽  
Vol 25 (4) ◽  
pp. 383-393 ◽  
Author(s):  
Yousmel Alemán Gaínza ◽  
Rafaela Regina Fantatto ◽  
Francisco Celio Maia Chaves ◽  
Humberto Ribeiro Bizzo ◽  
Sérgio Novita Esteves ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Steam Distillation ◽  
Resistant Isolate ◽  
Cross Resistance ◽  
Egg Hatch ◽  
Susceptible Isolate ◽  
Piper Aduncum ◽  
Eggs And Larvae ◽  
Larval Development Test

Abstract The anthelminthic activity of the essential oil (EO) of Piper aduncum L. was tested in vitro on eggs and larvae of resistant (Embrapa2010) and susceptible (McMaster) isolates of Haemonchus contortus. The EO was obtained by steam distillation and its components identified by chromatography. EO concentrations of 12.5 to 0.02 mg/mL were used in the egg hatch test (EHT) and concentrations of 3.12 to 0.01 mg/mL in the larval development test (LDT). Inhibition concentrations (IC) were determined by the SAS Probit procedure, and significant differences assessed by ANOVA followed by Tukey’s test. In the EHT, the IC50 for the susceptible isolate was 5.72 mg/mL. In the LDT, the IC50 and IC90 were, respectively, 0.10 mg/mL and 0.34 mg/mL for the susceptible isolate, and 0.22 mg/mL and 0.51 mg/mL for the resistant isolate. The EO (dillapiole 76.2%) was highly efficacious on phase L1. Due to the higher ICs obtained for the resistant isolate, it was raised the hypothesis that dillapiole may have a mechanism of action that resembles those of other anthelmintic compounds. We further review and discuss studies, especially those conducted in Brazil, that quantified the major constituents of P. aduncum-derived EO.

Efficacy of the cyclooctadepsipeptide PF1022A againstHeligmosomoides bakeri in vitroandin vivo

Parasitology ◽  
2011 ◽  
Vol 138 (9) ◽  
pp. 1193-1201 ◽  
Author(s):  
UZOMA NWOSU ◽  
MIREILLE VARGAS ◽  
ACHIM HARDER ◽  
JENNIFER KEISER
Keyword(s):  
Worm Burden ◽  
Anthelmintic Activity ◽  
Gastrointestinal Nematodes ◽  
Laboratory Model ◽  
Egg Hatch ◽  
Larval Stages ◽  
Nematocidal Activity ◽  
Heligmosomoides Bakeri

SUMMARYThe cyclooctadepsipeptide PF1022A derived from the fungus,Mycelia sterilia, is characterized by a broad spectrum of activity against different parasitic gastrointestinal nematodes of livestock. In the present work the anthelmintic activity of PF1022A againstHeligmosomoides bakeri, a widely used laboratory model was studied. Albendazole, ivermectin and levamisole served as reference.In vitro, PF1022A showed low activity on embryonation but significantly inhibited egg hatch (10 and 100μg/ml), whereas albendazole (10 and 100μg/ml) revealed statistically significant inhibitions of both embryonation and egg hatch. PF1022A (1–100μg/ml) completely inhibited larval movement at most examination points. Comparable significant anthelmintic activity on the larval stages ofH. bakeriwas observed with levamisole (48–100%), while slightly lower activities were observed with ivermectin (20–92%) and albendazole (0–87%) at 1–100μg/ml. PF1022A and levamisole significantly inhibited motility and egg release of adult worms, while albendazole and ivermectin failed to demonstrate activity. Significant worm burden reductions were achieved with PF1022A, levamisole and ivermectinin vivo. For example, at 0·125 mg/kg PF1022A a worm burden reduction of 91·8% was observed. The use of drug combinations did not further enhance thein vitroandin vivoactivity of PF1022A. In conclusion, further investigations are warranted with PF1022A, as the drug is characterized by significant larvicidal and nematocidal activityin vitroandin vivo.

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