Levels of benzimidazole resistance in Haemonchus contortus and Trichostrongylus colubriformis recorded from an egg hatch test procedure

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.

Download Full-text

The effects of benzimidazole resistance and route of administration on the uptake of fenbendazole and thiabendazole by Haemonchus contortus and Trichostrongylus colubriformis in sheep

Veterinary Parasitology ◽

10.1016/0304-4017(78)90051-1 ◽

1978 ◽

Vol 4 (3) ◽

pp. 243-255 ◽

Cited By ~ 31

Author(s):

R.K. Prichard ◽

J.D. Kelly ◽

H.G. Thompson

Keyword(s):

Haemonchus Contortus ◽

Route Of Administration ◽

Trichostrongylus Colubriformis ◽

Benzimidazole Resistance

Download Full-text

Standardization of the egg hatch test for the detection of benzimidazole resistance in parasitic nematodes

Parasitology Research ◽

10.1007/s00436-009-1466-1 ◽

2009 ◽

Vol 105 (3) ◽

pp. 825-834 ◽

Cited By ~ 71

Author(s):

Georg von Samson-Himmelstjerna ◽

Gerald C. Coles ◽

Frank Jackson ◽

Christian Bauer ◽

Fred Borgsteede ◽

...

Keyword(s):

Parasitic Nematodes ◽

Egg Hatch ◽

Benzimidazole Resistance ◽

Egg Hatch Test

Download Full-text

Essential oils from Ocimum basilicum cultivars: analysis of their composition and determination of the effect of the major compounds on Haemonchus contortus eggs

Journal of Helminthology ◽

10.1017/s0022149x21000080 ◽

2021 ◽

Vol 95 ◽

Author(s):

A.I.P. Sousa ◽

C.R. Silva ◽

H.N. Costa-Júnior ◽

N.C.S. Silva ◽

J.A.O. Pinto ◽

...

Keyword(s):

Essential Oils ◽

Haemonchus Contortus ◽

Anthelmintic Activity ◽

Gastrointestinal Nematodes ◽

Ocimum Basilicum ◽

Alternative Methods ◽

Egg Hatch ◽

Plant Essential Oils ◽

Methyl Chavicol ◽

The Individual

Abstract The continuous use of synthetic anthelmintics against gastrointestinal nematodes (GINs) has resulted in the increased resistance, which is why alternative methods are being sought, such as the use of natural products. Plant essential oils (EOs) have been considered as potential products for the control of GINs. However, the chemical composition and, consequently, the biological activity of EOs vary in different plant cultivars. The aim of this study was to evaluate the anthelmintic activity of EOs from cultivars of Ocimum basilicum L. and that of their major constituents against Haemonchus contortus. The EOs from 16 cultivars as well the pure compound linalool, methyl chavicol, citral and eugenol were used in the assessment of the inhibition of H. contortus egg hatch. In addition, the composition of three cultivars was simulated using a combination of the two major compounds from each. The EOs from different cultivars showed mean Inhibition Concentration (IC50) varying from 0.56 to 2.22 mg/mL. The cultivar with the highest egg-hatch inhibition, Napoletano, is constituted mainly of linalool and methyl chavicol. Among the individual compounds tested, citral was the most effective (IC50 0.30 mg/mL). The best combination of compounds was obtained with 11% eugenol plus 64% linalool (IC50 0.44 mg/mL), simulating the Italian Large Leaf (Richters) cultivar. We conclude that different cultivars of O. basilicum show different anthelmintic potential, with cultivars containing linalool and methyl chavicol being the most promising; and that citral or methyl chavicol isolated should also be considered for the development of new anthelmintic formulations.

Download Full-text

Identification and quantification of benzimidazole resistance polymorphisms in Haemonchus contortus isolated in Northeastern Brazil

Veterinary Parasitology ◽

10.1016/j.vetpar.2013.11.006 ◽

2014 ◽

Vol 199 (3-4) ◽

pp. 160-164 ◽

Cited By ~ 32

Author(s):

Jessica Maria Leite dos Santos ◽

Jomar Patrício Monteiro ◽

Wesley Lyeverton Correia Ribeiro ◽

Iara Tersia Freitas Macedo ◽

Ana Lourdes Fernandes Camurça-Vasconcelos ◽

...

Keyword(s):

Haemonchus Contortus ◽

Northeastern Brazil ◽

Benzimidazole Resistance ◽

Identification And Quantification

Download Full-text

Bacterial Culture Filtrates Antinematode Activity of Abomasum Bacterial Culture Filtrates against Haemonchus contortus in Small Ruminants

Animals ◽

10.3390/ani11061843 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1843

Author(s):

Asfa Nazish ◽

Fozia ◽

Baharullah Khattak ◽

Taj Ali Khan ◽

Ijaz Ahmad ◽

...

Keyword(s):

Haemonchus Contortus ◽

Bacterial Culture ◽

Small Ruminants ◽

Adult Mortality ◽

Comamonas Testosteroni ◽

Bacterial Isolates ◽

Egg Hatch ◽

Nematode Parasites ◽

Culture Filtrates ◽

Nematode Mortality

Haemonchosis is a parasitic disease of small ruminants that adversely affects livestock production. Haemonchus contortus is one of the most prevalent nematode parasites that infect the abomasum of small ruminants. This parasite reduces milk production, overall growth and sometimes causes the death of the infected animals. The evaluation of the biocontrol potential of some abomasum bacterial isolates against H. contortus is investigated in this study. Out of which, three isolates—Comamonas testosteroni, Comamonas jiangduensis, Pseudomonas weihenstephanesis—show significant effect against the nematode L3, adult, and egg hatch inhibition assays. Various concentrations of metabolites from these bacteria are prepared and applied in different treatments compared with control. In the case of adult mortality assay, 50% metabolites of C. testosteroni and P. weihenstephanesis show 46% adult mortality, whereas C. jiangduensis shows 40% mortality. It is observed that decreasing the concentration of bacterial metabolite, lowers nematode mortality. The minimum nematode mortality rate is recorded at the lowest filtrates concentration of all the bacterial isolates. The same trend is observed in egg hatch inhibition assay, where the higher concentration of bacterial culture filtrates shows 100% inhibition of H. contortus egg. It is concluded that the effect of bacterial culture filtrates against H. contortus is dose-dependent for their activity against nematode L3, adult, and inhibition of egg hatchment.

Download Full-text