Screening for anthelmintic resistance in equid strongyles (Nematoda) in Romania

Abstract

Resistance to anthelmintic medication of equid strongyles is a worldwide phenomenon and for this reason systematic investigations of resistant parasite populations are necessary. The purpose of the present study was to investigate the presence and distribution of equid strongyles resistant to the anthelmintics used in Romania, as well as the pre-treatment and post-treatment prevalence of species of strongylid nematodes. The Faecal Egg Count Reduction Test was performed between 2010 and 2013 on a total number of 588 horses and 23 donkeys from 26 locations (subgroups). Animals of the first group (I) consisting of subgroups no. 1-11 were treated with Albendazole (ABZ), those of the second group (II) consisting of subgroups no. 12-23 with Fenbendazole (FBZ), while Ivermectin (IVM) was used on animals of the third group (III) consisting of subgroups no. 24-26. Resistant strongyles have been found in 82% (average lower limit of the 95% confidence interval, LCL95%, was 65) of the total equids from the group treated with ABZ. In the group of horses treated with FBZ, resistant strongyles were identified in 75% of the subgroups (LCL95% = 44). No resistant strongyles have been identified in IVM-treated horse groups (LCL95% = 98). The pre-treatment prevalence of the species of the Strongylinae Müller, 1780 was 22%, whereas that with nematodes of the subfamily Cyathostominae Molin, 1861 78%. Post-treatment reduction of strongyline nematodes was observed (5%), which demonstrates the sensitivity of large strongyles to common anthelmintics. The post-treatment prevalence of cyathostomes was of 95%, which proves their resistance, especially to ABZ- and FBZ-based anthelmintics.

Investigating the Strongyle Populations, with Emphasis on Strongylus vulgaris (Nematoda: Strongylidae) in Romanian Horses, Based on Larval Cultures

“…Through larval culturing, this study revealed mixed strongyle populations, comprising a complex of cytostomin species, with the morphotype A as predominat, but also strongylin species, including S. vulgaris, S. edentatus, and S. equinus in working horses. These results are consistent also with previous studies carried out in Romania reporting a prevalence of 10.3% for S. vulgaris (Cernea et al, 2015). Different surveys showed that the S. vulgaris species is more commonly found in working horses, as it was in the present study, or in horses from farms where anthelmintic treatments are iregularly administered or with a lower intensity (Kyvsgaard et al, 2011).…”

In Vitro Pharmacodynamics of Benzimidazole and Tetrahydropyrimidine Derivatives in European Bison Gastro-Intestinal Nematodes

“…The results show that bison strongyle populations are still very sensitive to benzimidazoles and tetrahydropyrimidines, totally diferent, compared to strongyle populations in horsers, which already developed a wide resistance against benzimidazoles, especially against ABZ (Cernea et al, 2015).…”

“…From the EC 50 point of view, the maximum efficacy was recorded in MBZ and TBZ, the last being ABZ with a EC 50 of 0.326 mcg/ml. However, according to the standard interpretation of this test, in which the tested parasite population is considered to be resistant if the hatching percentage at the reference concentration (0.15 mcg/ml) is higher than 50% (Cernea et al, 2015;Coles et al, 1992), all tested benzimidazoles have been shown to present hatching percentages as low as 50%. From this point of view, the best efficacy was recorded with MBZ, followed by TBZ and ABZ.…”

“…If a poorly effective drug is used or if the efficient medication is underdosed, development of drug resistance occurs (Cernea et al, 2015, Woodbury et al, 2011. In order to be able to control these pathologies, it is important to monitor the dewormings and assess the effectiveness of the active ingredients used as antiparasitic medication (Cernea et al, 2005, Demiaszkiewicz et al, 2010, Krzysiak et al, 2015.…”

Effect of Spermine, Epibrassinolid and their interaction on inflorescence buds and fruits abscission of pistachio tree (Pistacia vera L.), “Ahmad–Aghai” cultivar

“…Carbohydrate content and soluble sugars are highly correlated to fruit abscission. BRs lead to a specific enhancement of leaf carbohydrate content [GOETZ et al, 2000, CERNEA, et al, 2015, BUTNARIU and GIUCHICI, 2011 . In this study, epibrassinolid treatments significantly increased the amount of carbohydrates in leaves while it reduced fruit and bud abscission.…”