Efficacy of nitroxynil against Fasciola hepatica resistant to triclabendazole in a naturally infected sheep flock

Abstract

The aim of this study was to compare the efficacy of triclabendazole (TCBZ) and nitroxynil against a TCBZ-resistant Fasciola hepatica strain in a naturally infected sheep flock. The efficacies were measured by the faecal egg count reduction test. The level of F. hepatica antigens was tested in faeces; and haematological indices such as total proteins (TP), albumin, hepatic enzymes and total IgG were also studied. The results confirmed the resistance of F. hepatica against TCBZ in the flock with an efficacy during the first month post-treatment between 59.4% and 73.8%. In the nitroxynil group, the efficacy during the same period ranged between 81.3% and 86%, likely because the efficacy of this drug against 7- to 9-week-old immature stages is only 50-90%. Anemia was showed in all groups and white blood cells were always higher than the reference range. The values of TP and albumin were within normal range in most of the sheep, and an increase in hepatic enzymes confirmed the liver damage. Regarding total IgG, some negative correlations were found with egg excretion, and in relation to the level of antigens in faeces, these ones decreased immediately after treatment. We conclude that nitroxynil could be an alternative in case of TCBZ resistance.

Purification and characterization of Taenia crassiceps cysticerci thioredoxin: insight into thioredoxin-glutathione-reductase (TGR) substrate recognition

“…At present, drug resistance has been documented in several trematode species, such as S. mansoni [62][63][64] and F. hepatica [65][66][67]. In contrast, resistance to anthelminthic drugs has not been recognized in cestodes, even through a variety of different responses to treatments are documented [68].…”

Bovine fasciolosis: Control strategies based on the location of Galba truncatula habitats on farms

“…Of the several strategies for the control of bovine fasciolosis described, in practice usually strategic anthelmintic control is used with flukicide treatment time and interval depending on the climatic zone (Armour, 1975;Boray, 1971Boray, , 1972Harris and Charleston, 1971;Schneider et al, 1975;Torgerson and Claxton, 1999;Whitehead, 1976). A variety of fasciolicides is available for the treatment of bovine fasiolosis: triclabendazole, albendazole, oxyclozanide, clorsulon, nitroxynil, rafoxanide or oxfendazole (Fairweather, 2011;Gomez-Puerta et al, 2012;Martínez-Valladares et al, 2010). Of all these agents, triclabendazole is the most effective against immature stages of the parasite, which makes it the drug of choice for the treatment of acute fasciolosis, which is more commonly seen in sheep than in cattle.…”

Research of nitroxynil residues in bovine milk following a single administration in the dry period by ultra-performance liquid chromatography tandem mass spectrometry

“…When compared with other fasciolicides, this compound shows high activity against both adult and immature liver flukes (Martínez-Valladares et al, 2010;McKinstry et al, 2009;Hutchinson et al, 2009). Recently the Commission Regulation (EU) No 201/2012(European Commission, 2012 has amended the Annex of the Regulation (EU) No 37/2010 (European Commission, 2010) on pharmacologically active substances and their classification regarding maximum residue limits in foodstuffs of animal origin and maximum residue limits (MRLs) for the marker residue NIT in bovine and ovine milk was established at 20 g/kg −1 .…”