Miller, C.M.D., Howell, M.J., and Boray, J.C. (1994) Glutathione S-transferases as markers of salicylanilide resistance in isolates of Fasciola hepatica. International Journal for Parasitology, 24 (4). pp. 533-542.

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Abstract

A possible link between the level of glutathione S-transferase (GST, E.C. 2.5.1.18) activity and the development of salicylanilide resistance in Fasciola hepatica was investigated. Various isolates of F. hepatica with varying susceptibilities to salicylanilides were isolated and maintained in the laboratory. Individual flukes of these isolates were surveyed for their level of GST activity and a correlation between the level of GST activity and drug efficacy was found. In contrast to most other studies, a decrease in GST activity was associated with an increase in drug resistance. Evidence was collected to show that this may be a selective process since flukes which had survived exposure to rafoxanide and closantel in vivo (in sheep) had lower activity levels of GST than flukes from untreated sheep. Treatment with other flukicides (oxyclozanide, luxabendazole and triclabendazole) did not have this effect. Furthermore, in vivo treatment with closantel induced selection of particular isoenzymes in different isolates of F. hepatica having different degrees of susceptibility to closantel. However, no single isoenzyme or isoenzyme profile was associated with resistance and, in total, up to 8 different isoenzymes could be present in a single isolate. Thus, GST has some potential as a marker enzyme for salicylanilide resistance in F. hepatica. However, the precise role of GST in resistance is unclear and the extensive inter- and intra-isolate variation in activity levels and isoenzyme characteristics of this enzyme indicate the need for considerably more study before application in field situations.

Item ID:	34616
Item Type:	Article (Research - C1)
ISSN:	1879-0135
Keywords:	Fasciola hepatica; glutathione S-transferases; salicylanilide resistance; sheep
Funders:	Australian Wool Corporation
Date Deposited:	26 Aug 2014 04:54
FoR Codes:	07 AGRICULTURAL AND VETERINARY SCIENCES > 0702 Animal Production > 070205 Animal Protection (Pests and Pathogens) @ 50% 07 AGRICULTURAL AND VETERINARY SCIENCES > 0707 Veterinary Sciences > 070708 Veterinary Parasitology @ 50%
SEO Codes:	83 ANIMAL PRODUCTION AND ANIMAL PRIMARY PRODUCTS > 8303 Livestock Raising > 830311 Sheep - Wool @ 20% 97 EXPANDING KNOWLEDGE > 970107 Expanding Knowledge in the Agricultural and Veterinary Sciences @ 40% 97 EXPANDING KNOWLEDGE > 970106 Expanding Knowledge in the Biological Sciences @ 40%
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