Evaluation of in vitro methods of anthelmintic efficacy testing against Ascaridia galli

Feyera, Teka; Elliott, Timothy; Sharpe, Brendan; Ruhnke, Isabelle; Shifaw, Anwar; Walkden-Brown, Stephen W

doi:10.1017/S0022149X22000177

Author(s)

Feyera, Teka

Elliott, Timothy

Sharpe, Brendan

Ruhnke, Isabelle

Shifaw, Anwar

Walkden-Brown, Stephen W

Publication Date

2022-04-19

Abstract

To investigate methods for in vitro assessment of anthelmintic efficacy against the chicken nematode Ascaridia galli this study firstly evaluated sample preparation methods including recovery of eggs from excreta using different flotation fluids and induced larval hatching by the deshelling–centrifugation method and the glass-bead method with or without bile. It then evaluated two in vitro assays, the in-ovo larval development assay (LDA) and larval migration inhibition assay (LMIA), for anthelmintic efficacy testing against A. galli using fresh eggs and artificially hatched larvae, respectively. Four anthelmintics, thiabendazole (TBZ), fenbendazole (FBZ), levamisole (LEV) and piperazine (PIP) were employed using an A. galli isolate of known susceptibility. The results suggested that the LDA and LMIA could successfully be used to generate concentration response curves for the tested drugs. The LDA provided EC50 values for inhibition of egg embryonation of 0.084 and 0.071 μg/ml for TBZ and FBZ, respectively. In the LMIA, the values of effective concentration (EC50) of TBZ, FBZ, LEV and PIP were 105.9, 6.32, 349.9 and 6.78 × 107 nM, respectively. For such in vitro studies, a saturated sugar solution showed high egg recovery efficiency (67.8%) and yielded eggs of the highest morphological quality (98.1%) and subsequent developmental ability (93.3%). The larval hatching assays evaluated did not differ in hatching efficiency but the deshelling–centrifugation method yielded larvae that had slightly better survival rates. For final standardization of these tests and establishment of EC50 reference values, tests using isolates of A. galli of defined resistance status need to be performed.

Citation

Journal of Helminthology, v.96, p. 1-12

ISSN

1475-2697

0022-149X

Link

https://hdl.handle.net/1959.11/69018

Language

en

Publisher

Cambridge University Press

Rights

Attribution 4.0 International

Title

Evaluation of in vitro methods of anthelmintic efficacy testing against Ascaridia galli

Type of document

Journal Article

Entity Type

Publication

Author(s)	Feyera, Teka Elliott, Timothy Sharpe, Brendan Ruhnke, Isabelle Shifaw, Anwar Walkden-Brown, Stephen W
Publication Date	2022-04-19
Abstract	<p>To investigate methods for <i>in vitro</i> assessment of anthelmintic efficacy against the chicken nematode <i>Ascaridia galli</i> this study firstly evaluated sample preparation methods including recovery of eggs from excreta using different flotation fluids and induced larval hatching by the deshelling–centrifugation method and the glass-bead method with or without bile. It then evaluated two <i>in vitro</i> assays, the in-ovo larval development assay (LDA) and larval migration inhibition assay (LMIA), for anthelmintic efficacy testing against <i>A. galli</i> using fresh eggs and artificially hatched larvae, respectively. Four anthelmintics, thiabendazole (TBZ), fenbendazole (FBZ), levamisole (LEV) and piperazine (PIP) were employed using an <i>A. galli</i> isolate of known susceptibility. The results suggested that the LDA and LMIA could successfully be used to generate concentration response curves for the tested drugs. The LDA provided EC<sub>50</sub> values for inhibition of egg embryonation of 0.084 and 0.071 μg/ml for TBZ and FBZ, respectively. In the LMIA, the values of effective concentration (EC<sub>50</sub>) of TBZ, FBZ, LEV and PIP were 105.9, 6.32, 349.9 and 6.78 × 10<sup>7</sup> nM, respectively. For such <i>in vitro</i> studies, a saturated sugar solution showed high egg recovery efficiency (67.8%) and yielded eggs of the highest morphological quality (98.1%) and subsequent developmental ability (93.3%). The larval hatching assays evaluated did not differ in hatching efficiency but the deshelling–centrifugation method yielded larvae that had slightly better survival rates. For final standardization of these tests and establishment of EC<sub>50</sub> reference values, tests using isolates of <i>A. galli</i> of defined resistance status need to be performed. </p>
Citation	Journal of Helminthology, v.96, p. 1-12
ISSN	1475-2697 0022-149X
Link	https://hdl.handle.net/1959.11/69018
Language	en
Publisher	Cambridge University Press
Rights	Attribution 4.0 International
Title	Evaluation of in vitro methods of anthelmintic efficacy testing against Ascaridia galli
Type of document	Journal Article
Entity Type	Publication

Evaluation of in vitro methods of anthelmintic efficacy testing against Ascaridia galli

Files: