A new simplified assay for larval migration inhibition

Wagland, B.M.; Jones, W.O.; Hribar, Lawrence J.; Bendixsen, Tuan; Emery, D.L.

doi:10.1016/0020-7519(92)90040-r

Cited by 61 publications

(35 citation statements)

References 9 publications

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“…Inhibitory effects were measured using a larval migration inhibition assay. This assay has been successfully used to test the inhibitory effects of proprietary anthelmintic drenches (Wagland et al 1992, Rabel et al 1994, Lorimer et al 1996.…”

Section: Discussionmentioning

confidence: 99%

“…The larval migration inhibition (LMI) bioassay procedure developed by Wagland et al (1992) and modified by Rabel et al (1994) was used to determine the inhibiting effect of purified CT against T. colubriformis. The method involved preparation of test solutions with CT and of L3 larvae which were combined and incubated in the wells of tissue culture plates (Costar, Cambridge, MA).…”

Section: Experimental Designmentioning

confidence: 99%

See 1 more Smart Citation

The effect of condensed tannins from seven herbages on Trichostrongylus colubriformis larval migration in vitro

Molan¹,

Waghorn²,

Min³

et al. 2000

FOLIA PARASIT

141

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Abstract. The effects of condensed tannins (CT) extracted from seven forages on the motility of the economically important nematode, Trichostrongylus colubriformis (Giles, 1892), were evaluated by using a larval migration inhibition (LMI) assay. The assay involved incubation of third stage (L3) exsheathed T. colubriformis larvae with CT extracted from Lotus pedunculatus, Lotus corniculatus, sulla (Hedysarum coronarium), sainfoin (Onobrychis viciifolia), Dorycnium rectum, Dorycnium pentaphyllum and dock (Rumex obtusifolius) and measurement of larval migration through nylon mesh with a 20µm pore size. At 100 µg ml -1 , CT from L. pedunculatus, L. corniculatus, sulla, sainfoin, D. rectum, D. pentaphyllum and dock inhibited 20%, 10%, 15%, 25%, 28%, 32% and 27% of the larvae, respectively from passing through the sieves compared to controls (no CT added). At 1000 µg CT ml -1 , CT purified from D. pentaphyllum had the highest inhibitory activity (63%) against 1-month old larvae followed by sainfoin (59%), L. pedunculatus (57%), D. rectum (53%), dock (50%), sulla (40%) and L. corniculatus (37%). Seven-month old larvae were more sensitive to the action of CT than 1-month old larvae (P < 0.001). Addition of 2 µg polyethylene glycol ([PEG] per µg CT; to remove the effect of CT) eliminated 81-93% of the CT activity (P < 0.001) compared to incubations without PEG. The impact of CT on larval migration suggests a possible role for these plants in ruminant diets as a means to reduce dependence upon proprietary anthelmintics.

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Section: Discussionmentioning

confidence: 99%

Section: Experimental Designmentioning

confidence: 99%

The effect of condensed tannins from seven herbages on Trichostrongylus colubriformis larval migration in vitro

Molan¹,

Waghorn²,

Min³

et al. 2000

FOLIA PARASIT

141

View full text Add to dashboard Cite

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“…Generally, sheathed or exsheathed larvae can be used for this test (Wagland et al 1992). In this study, larvae were exsheathed as described by Samson-Himmelstjerna et al (1998) in sodium hypochlorite solution (0.15 %), washed three times with saline by means of centrifugation (3 min, 51 g) and the supernatant removed.…”

Section: Exsheathment Of Larvaementioning

confidence: 99%

Effects of Emodepside on Egg Hatching, Larval Development and Larval Motility in Parasitic Nematodes

et al. 2007

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The effects of the two anthelmintics PF1022A and emodepside were examined at the egg and free-living larval stages of several species of gastrointestinal nematodes. The in vitro assays used herein address the possible inhibitory effects of the cyclooctadepsipeptides (CODs) on egg hatching, larval development and larval motility. The egg hatch assay (EHA) and the larval development assay (LDA) were carried out using stages of Haemonchus contortus and cyathostomins of the horse. In the larval motility inhibition test (LMIT) only emodepside was used. The LMIT was performed with larval stages from Cooperia oncophora, Ostertagia ostertagi, H. contortus, Ancylostoma caninum and cyathostomins. To comparatively assess the effects of CODs and other anthelmintics, levamisole (LEV) and ivermectin (IVM) were also investigated. Ovicidal effects of the COD in the EHA were not observed even at the highest concentrations possible. The LDA showed the inhibitory activity of emodepside on larval development, which differed only slightly between the species tested. The LMIT demonstrated the inhibitory effects of emodepside on larval migration, with similar EC50 values across all species tested. The most susceptible species was A. caninum, the least susceptible was H. contortus. For all drugs tested a clear order of potency was observed: IVM was the most potent anthelmintic, LEV the least potent. With EC50 values of 2.25-8.28 µM, emodepside ranged between the two. In the present study the LDA and LMIT have been successfully established to monitor the activity of emodepside.

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“…Another potential alternative that is still being studied for the detection of resistant parasites is the larval migration tests (LMT). The LMT has being used for the detection of drug resistance for IVM, MOX and the benzimidazoles in sheep, goats and cattle nematodes (Wagland et al 1992, Rabel et al 1994, Molento & Prichard 2001, Gatongi et al 2003, Kaplan et al 2007, Demeler et al 2010, Almeida et al 2012. The development of IVM resistance and also the concomitant loss of sensitivity to MOX is an ongoing debate (Conder et al 1993, Shoop et al 1993, Molento et al 1999, Ranjan et al 2002, De Graef et al 2012.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of resistance in a selected field strain of Haemonchus contortus to ivermectin and moxidectin using the Larval Migration on Agar Test

et al. 2013

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Haemonchus contortus is one of the most common and economically significant causes of disease in small ruminants worldwide, and the control programs of parasitic nematodes -including H. contortus -rely mostly on the use of anthelmintic drugs. The consequence of the use of this, as the sole sanitary strategy to avoid parasite infections, was the reduction of the efficacy of all chemotherapeutic products with a heavy selection for resistance. The widespread of anthelmintic resistance and the difficulty of its early diagnosis has been a major concern for the sustainable parasite management on farms. The objective of this research was to determine and compare the ivermectin (IVM) and moxidectin (MOX) effect in a selected field strain of H. contortus with a known resistance status, using the in vitro larval migration on agar test (LMAT). Third stage larvae of the selected isolate were obtained from faecal cultures of experimentally infected sheep and incubated in eleven increasing diluted concentrations of IVM and MOX (6, 12, 24, 48, 96, 192, 384, 768, 1536, 3072 and 6144µg/mL). The dose-response sigmoidal curves were obtained using the R 2 value of >0.90 and the lethal concentration (LC 50 ) dose for the tested anthelmintic drugs using a four-parameter logistic model. The LC 50 value for MOX was significantly lower than IVM (1.253µg/mL and 91.06µg/mL), identifying the H. contortus isolate as considerably less susceptible to IVM compared to MOX. Furthermore, the LMAT showed a high consistency (p<0.0001) and provided to be a useful diagnostic tool for monitoring the resistance status of IVM and MOX in H. contortus field isolate, as well as it may be used for official routine drug monitoring programs under the Ministry of Agriculture (MAPA) guidance. mais comuns e economicamente significativas de doença em produções de pequenos ruminantes em todo o mundo, e os programas de controle de parasitas nematoides -incluindo H. contortus -baseiam-se principalmente no uso de drogas anti-helmínticas. A consequência da utilização desses compostos, como sendo a única estratégia sanitária para evitar infecções por parasitas, tem sido a redução da eficácia de todos os produtos quimioterápicos, selecionando fortemente para resistência. O desenvolvimento generalizado da resistência anti-helmíntica e a dificuldade de seu diagnóstico precoce têm sido uma grande preocupação para o manejo sustentável de parasitas no campo. O obje- (6, 12, 24, 48, 96, 192, 384, 768, 1536, 3072 e 6144µg/mL). As curvas sigmoides de dose-resposta foram obtidas utilizando o valor de R 2 >0,90 e a dose de concentração letal (CL 50 ) para as drogas anti-helmínticas testadas, utilizando um modelo logístico de quatro parâ-metros. O valor de CL 50 para MOX foi significativamente menor do que para IVM (1,253µg/mL e 91,06µg/mL), identificando o isolado de H. contortus como consideravelmente menos suscetível à IVM em comparação à MOX. Além disso, o LMTA mostrou uma alta consistência (p<0,0001) e pode ser uma ferramenta útil de diagnóstico para monitorar o status de ...

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A new simplified assay for larval migration inhibition

Cited by 61 publications

References 9 publications

The effect of condensed tannins from seven herbages on Trichostrongylus colubriformis larval migration in vitro

The effect of condensed tannins from seven herbages on Trichostrongylus colubriformis larval migration in vitro

Effects of Emodepside on Egg Hatching, Larval Development and Larval Motility in Parasitic Nematodes

Evaluation of resistance in a selected field strain of Haemonchus contortus to ivermectin and moxidectin using the Larval Migration on Agar Test

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