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.

Measuring the effect of avermectins and milbemycins on somatic muscle contraction of adult Haemonchus contortus and on motility of Ostertagia circumcincta in vitro

Parasitology ◽  
2014 ◽  
Vol 141 (7) ◽  
pp. 948-956 ◽  
Author(s):  
JANINA DEMELER ◽  
GEORG VON SAMSON-HIMMELSTJERNA ◽  
NICHOLAS C. SANGSTER
Keyword(s):  
Muscle Contraction ◽  
Haemonchus Contortus ◽  
Anthelmintic Resistance ◽  
Parasitic Nematodes ◽  
Response Curves ◽  
Drug Potency ◽  
The Right ◽  
Sites Of Action

SUMMARYThe mechanism of anthelmintic resistance against the widely used macrocyclic lactones (MLs) is still not fully understood. Pharyngeal, somatic body muscles and the ovijector have been proposed as putative sites of action as well as resistance. In the present study the effects of three avermectins and three milbemycins on adult parasitic nematodes were evaluated in vitro. The Muscle Transducer system was used to investigate the effects of MLs on muscle contraction in female Haemonchus contortus and effects on motility were measured in Ostertagia (Teladorsagia) circumcincta using the Micromotility Meter. Concentration-response curves for all substances in both systems shifted to the right in the resistant isolates. Resistance was present to ivermectin (IVM) and its components IVM B1a and IVM B1b, suggesting that both components are involved in the mode of action and resistance. No consistent patterns of potency and resistance of the substances were observed except that milbemycins generally showed lower resistance ratios (RRs) than IVM. IVM and IVM B1b were the most potent inhibitors of contraction and motility in both susceptible isolates and also showed the highest RR in both species. Low RRs for milbemycins recorded in vitro for highly resistant isolates in vivo suggest that other factors such as pharmacokinetics influence drug potency in vivo.

scholarly journals Anthelmintic activity of Cymbopogon citratus against Haemonchus contortus

2015 ◽  
Vol 24 (3) ◽  
pp. 268-275 ◽  
Author(s):  
Iara Tersia Freitas Macedo ◽  
Lorena Mayana Beserra de Oliveira ◽  
Wesley Lyeverton Correia Ribeiro ◽  
Jessica Maria Leite dos Santos ◽  
Kaline das Chagas Silva ◽  
...  
Keyword(s):  
Essential Oil ◽  
Haemonchus Contortus ◽  
Anthelmintic Activity ◽  
Meriones Unguiculatus ◽  
Parasitic Nematodes ◽  
Control Group ◽  
Cymbopogon Citratus ◽  
Egg Hatching

Parasitic nematodes are of major economic importance in livestock. An alternative for the control of parasites is phytotherapy. This study evaluated the efficacy of Cymbopogon citratus decoction (CcD), C. citratus essential oil (CcEo) and citral against Haemonchus contortus using in vitro egg hatch test (EHT) and larval development test (LDT) and an in vivo test using a Meriones unguiculatus (gerbil) model. The effect of 800 mg/kg CcEo was evaluated in gerbils that had been artificially infected with 5,000 third-stage H. contortus larvae. The effective concentrations required to inhibit 50% (EC50) of egg hatching were 0.46, 0.14 and 0.13 mg/mL for CcD, CcEo and citral, respectively. The EC50 values in the LDT were 5.04, 1.92 and 1.37 mg/mL for CcD, CcEo and citral, respectively. H. contortus population in the group treated with C. citratus essential oil was reduced by 38.5% (P< 0.05) in comparison to the control group. These results suggest that it may be possible to use C. citratusessential oil to control of H. contortus parasite of small ruminant.

scholarly journals Worm-control practices and prevalence of anthelmintic resistance using in vivo FECRTs on smallholder sheep farms in Lithuania

2016 ◽  
Vol 53 (1) ◽  
pp. 24-30 ◽  
Author(s):  
T. Kupčinskas ◽  
I. Stadalienė ◽  
A. Šalomskas ◽  
P. Trusevičius ◽  
M. Varady ◽  
...  
Keyword(s):  
Anthelmintic Resistance ◽  
Gastrointestinal Nematodes ◽  
Parasitic Nematodes ◽  
Future Studies ◽  
Faecal Samples ◽  
Two Samples ◽  
Faecal Egg Count ◽  
Worm Control

SummaryThis study determined the prevalence of anthelmintic resistance (AR) in parasitic nematodes on smallholder sheep farms in Lithuania from April to November 2014. Faecal samples were collected from two groups of 10-15 sheep treated with fenbendazole (FBZ) or ivermectin (IVM) on 18 sheep farms. Two samples were collected from each group: on day zero (T1) and 10-14 days after treatment. Faecal egg counts (eggs per gramme, EPG) were determined using a modified McMaster technique. Animals with < 140 EPG on day zero were removed from the analysis. The prevalence of AR was estimated using the in vivo faecal egg count reduction test. AR to FBZ was detected on three of 15 farms where FBZ was used (20 %) and was suspected on one farm (6.7 %). AR to IVM was detected on two of 16 farms where IVM was used (12.5 %). The main species of resistant gastrointestinal nematodes (GINs) identified after treatment were Teladorsagia spp. and Trichostrongylus spp. A questionnaire surveying 71 sheep farmers estimated that 71.8 % of sheep farmers used anthelmintics against GINs. IVM was the most frequently (68.6 %) applied anthelmintic, and 62.7 % of the respondents reported treating their animals twice a year. This study confirmed the presence of AR to GIN infections on sheep farms in Lithuania. Future studies should assess the prevalence of AR to GIN infection using in vitro methods.

scholarly journals Characterization of a Rhodanese Homologue from Haemonchus Contortus and its Immune-Modulatory Effects on Goat Immune Cells in Vitro

2020 ◽  
Author(s):  
Yujian Wang ◽  
Muhammad Ehsan ◽  
Jianmei Huang ◽  
Kalibixiati Aimulajiang ◽  
RuoFeng Yan ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Mononuclear Cells ◽  
Small Ruminants ◽  
Parasitic Nematodes ◽  
Dependent Manner ◽  
Peripheral Blood Mononuclear ◽  
Nematode Parasites ◽  
Wide Range

Abstract Background: Suppression and modulation of the immune response of the host by nematode parasites have been reported widely. Rhodaneses or thiosulfate: cyanide sulfurtransferases are present in a wide range of organisms, such as archea, bacteria, fungi, plants and animals. Previously, it was reported that a rhodanese homology could bind by goat peripheral blood mononuclear cells (PBMCs) in vivo.Results: In the present study, we cloned and produced recombinant rhodanese protein originated from Haemonchus contortus (rHCRD), which was one of the parasitic nematodes of small ruminants. The effect of this protein on modulating the immunity of goat PBMC and monocyte was studied in the current work. The predominant localization of the natural HCRD protein was verified as the bowel wall and body surface of worms, according to the immunohistochemical tests. It was proved in this study that the serum produced by artificially infecting goats with H. contortus successfully recognized rHCRD which conjugated goat PBMCs. The rHCRD was co-incubated with goat PBMCs to observe the immunomodulatory effect on proliferation, apoptosis and secretion of cytokines exerted by HCRD. The results showed that the interaction of rHCRD suppressed proliferation of goat PBMCs stimulated by ConA but did not induce the apoptosis of goat PBMCs. After rHCRD exposure, the production of TNF-α and IFN-γ were significantly decreased, however, it significantly increased the secretion of IL-10 and TGF-β1 in goat PBMCs. Phagocytotic assay by FITC-dextran internalization showed that rHCRD inhibited the phagocytosis of goat monocytes. Moreover, rHCRD could down-regulate the expression of MHC-II on goat monocytes in a dose-dependent manner. Conclusions: These discoveries proposed a possible target as immunomodulator, which was potentially beneficial to illuminate the interaction between parasites and hosts in the molecular level and hunt for innovative protein species as candidate targets of drug and vaccine.

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.

scholarly journals Nanoparticles as Alternatives for the Control of Haemonchus contortus: A Systematic Approach to Unveil New Anti-haemonchiasis Agents

2021 ◽  
Vol 8 ◽  
Author(s):  
Rehman Ali ◽  
Nisar Ahmad ◽  
Sakina Mussarat ◽  
Abdul Majid ◽  
Sultan F. Alnomasy ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Anthelmintic Resistance ◽  
Small Ruminants ◽  
Gastrointestinal Nematode ◽  
Future Research ◽  
Cymbopogon Citratus ◽  
Toxicological Effects ◽  
Nano Emulsion

Haemonchus contortus is an infectious gastrointestinal nematode parasite of small ruminants. This study addresses the in vitro/in vivo anti-haemonchiasis potential, toxicological effects, and mechanism of action of nanoparticles. Online databases were used to search and retrieve the published literature (2000 to 2021). A total of 18 articles were selected and reviewed, out of which, 13 (72.2%) studies reported in vitro, 9 (50.0%) in vivo, and 4 (22.2%) both in vitro/in vivo efficacy of different nanoparticles. Mostly, organic nanoparticles (77.7%) were used including polymeric (85.7%) and lipid nanoparticles (14.3%). The highest efficacy, in vitro, of 100% resulted from using encapsulated bromelain against eggs, larvae, and adult worm mortality at 4, 2, and 1 mg/ml, respectively. While in vivo, encapsulated Eucalyptus staigeriana oil reduced worm burden by 83.75% and encapsulated Cymbopogon citratus nano-emulsion by 83.1%. Encapsulated bromelain, encapsulated Eucalyptus staigeriana oil, and encapsulated Cymbopogon citratus nano-emulsion were safe and non-toxic in vivo. Encapsulated bromelain damaged the cuticle, caused paralysis, and death. Nanoparticles could be a potential source for developing novel anthelmintic drugs to overcome the emerging issue of anthelmintic resistance in H. contortus. Studies on molecular effects, toxicological consequences, and different pharmacological targets of nanoparticles are required in future research.

Molecular detection of benzimidazole resistance in Haemonchus contortus using real-time PCR and pyrosequencing

Parasitology ◽  
2009 ◽  
Vol 136 (3) ◽  
pp. 349-358 ◽  
Author(s):  
G. von SAMSON-HIMMELSTJERNA ◽  
T. K. WALSH ◽  
A. A. DONNAN ◽  
S. CARRIÈRE ◽  
F. JACKSON ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Haemonchus Contortus ◽  
Anthelmintic Resistance ◽  
Allele Frequencies ◽  
Detection Methods ◽  
Resistance Testing ◽  
Β Tubulin

SUMMARYBenzimidazoles (BZ) are widely used to treat parasitic nematode infections of humans and animals, but resistance is widespread in veterinary parasites. Several polymorphisms in β-tubulin genes have been associated with BZ-resistance. In the present study, we investigated β-tubulin isotype 1 sequences of 18 Haemonchus contortus isolates with varying levels of resistance to thiabendazole. The only polymorphism whose frequency was significantly increased in the resistant isolates was TTC to TAC at codon 200. Real-time PCR (using DNA from 100 third-stage larvae, L3s) and pyrosequencing (from DNA from 1000–10 000 L3s) were used to measure allele frequencies at codon 200 of these isolates, producing similar results; drug sensitivity decreased with increasing TAC frequency. Pyrosequencing was also used to measure allele frequencies at positions 167 and 198. We showed that such measurements are sufficient to assess the BZ-resistance status of most H. contortus isolates. The concordance between real-time PCR and pyrosequencing results carried out in different laboratories indicated that these tools are suitable for the routine diagnosis of BZ-resistance in H. contortus. The molecular methods were more sensitive than the ‘egg hatch test’, and less time-consuming than current in vivo- or in vitro-anthelmintic resistance detection methods. Thus, they provide a realistic option for routine molecular resistance testing on farms.

Pharmacology of anthelmintic resistance

Parasitology ◽  
1996 ◽  
Vol 113 (S1) ◽  
pp. S201-S216 ◽  
Author(s):  
N. Sangster
Keyword(s):  
Acetylcholine Receptors ◽  
Anthelmintic Resistance ◽  
Cross Resistance ◽  
Parasitic Nematodes ◽  
Parasitic Helminths ◽  
Nematode Parasites ◽  
Neuromuscular Systems ◽  
Free Living Nematode ◽  
Molecular Aspects

SUMMARYAnthelmintic resistance has compromised the control of nematode parasites in several animal-based industries. Studies of resistance have not only improved our understanding of this phenomenon but also shed light on physiological systems of parasitic helminths. In addition, research on molecular aspects of anthelmintic resistance may provide selectable markers for use in future transfection studies with helminths. Several anthelmintics act on helminth neuromuscular systems. Drugs such as levamisole are cholinergic agonists and, based on pharmacological studies, levamisole-resistant nematodes appear to have altered acetylcholine receptors. It is likely that anticholinesterase anthelmintics share cross resistance with levamisole. Ivermectin appears to be a glutamate agonist.In vitrostudies of ivermectin-resistant nematodes suggest that IVM receptors are located on pharyngeal and somatic muscle. The free-living nematodeCaenorhabditis elegansmay provide a model for anthelmintic resistance. It has been useful in cloning drug receptors from parasites but differences between its life history and habitat compared with parasitic nematodes may limit its usefulness for studying resistance in these parasites.

scholarly journals Anthelmintic resistance of Haemonchus contortus from sheep flocks in Brazil: concordance of in vivo and in vitro (RESISTA-Test©) methods

2021 ◽  
Vol 30 (2) ◽  
Author(s):  
Yousmel Alemán Gainza ◽  
Isabella Barbosa dos Santos ◽  
Amanda Figueiredo ◽  
Leonardo Aparecido Lima dos Santos ◽  
Sérgio Novita Esteves ◽  
...  
Keyword(s):  
Larval Development ◽  
Haemonchus Contortus ◽  
Anthelmintic Resistance ◽  
Perfect Agreement ◽  
Fecal Egg Count ◽  
And Control ◽  
Total Agreement ◽  
Larval Development Test

Abstract This study evaluated the resistance status of Haemonchus contortus from sheep flocks in the state of São Paulo, Brazil, through comparison between the fecal egg count reduction test (FECRT) and the larval development test (LDT). For the FECRT, 35 sheep were selected in each of five flocks and divided into groups treated with: benzimidazole, levamisole, ivermectin, monepantel and control. Feces were collected for EPG and fecal cultures. The LDT was performed using thiabendazole (TBZ), levamisole (LEV), ivermectin aglycone (IVM-A) and Zolvix (ZLV). Resistance to all drugs was detected using FECRT in 100% of the flocks, except in relation to ZLV (40% resistant and 20% suspected of resistance). LDT indicated resistance to TBZ and IVM-A in all flocks, to LEV in 80% of flocks and to ZLV in 10%. Total agreement was obtained between the two tests for TBZ and IVM (k = 1.0), while for LEV (k = 0.8) and ZLV (k = 0.9), substantial and almost perfect agreement were obtained, respectively. The concordance between the tests was significant, thus showing that it is possible to use the outcome of the LDT to predict the FECRT, and hence validating the former as a fast diagnostic test for use by sheep farmers in Brazil.

scholarly journals Acyl-CoA oxidase ACOX-1 interacts with a peroxin PEX-5 to play roles in larval development of Haemonchus contortus

2021 ◽  
Vol 17 (7) ◽  
pp. e1009767
Author(s):  
Hengzhi Shi ◽  
Xiaocui Huang ◽  
Xueqiu Chen ◽  
Yi Yang ◽  
Zhao Wang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Larval Development ◽  
Haemonchus Contortus ◽  
Developmental Regulation ◽  
Tissue Expression ◽  
Parasitic Nematodes ◽  
Acid Oxidation ◽  
Oxidation Activity

Hypobiosis (facultative developmental arrest) is the most important life-cycle adaptation ensuring survival of parasitic nematodes under adverse conditions. Little is known about such survival mechanisms, although ascarosides (ascarylose with fatty acid-derived side chains) have been reported to mediate the formation of dauer larvae in the free-living nematode Caenorhabditis elegans. Here, we investigated the role of a key gene acox-1, in the larval development of Haemonchus contortus, one of the most important parasitic nematodes that employ hypobiosis as a routine survival mechanism. In this parasite, acox-1 encodes three proteins (ACOXs) that all show a fatty acid oxidation activity in vitro and in vivo, and interact with a peroxin PEX-5 in peroxisomes. In particular, a peroxisomal targeting signal type1 (PTS1) sequence is required for ACOX-1 to be recognised by PEX-5. Analyses on developmental transcription and tissue expression show that acox-1 is predominantly expressed in the intestine and hypodermis of H. contortus, particularly in the early larval stages in the environment and the arrested fourth larval stage within host animals. Knockdown of acox-1 and pex-5 in parasitic H. contortus shows that these genes play essential roles in the post-embryonic larval development and likely in the facultative arrest of this species. A comprehensive understanding of these genes and the associated β-oxidation cycle of fatty acids should provide novel insights into the developmental regulation of parasitic nematodes, and into the discovery of novel interventions for species of socioeconomic importance.

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