Martin Frida, Höglund Johan, Bergström Tomas F, Karlsson Lindsjö Oskar, Tydén Eva
Swedish University of Agricultural Sciences, Department of Biomedical Sciences and Veterinary Public Health, Division of Parasitology, Uppsala, Sweden.
Swedish University of Agricultural Sciences, Department of Biomedical Sciences and Veterinary Public Health, Division of Parasitology, Uppsala, Sweden.
Vet Parasitol. 2018 Dec 15;264:69-73. doi: 10.1016/j.vetpar.2018.11.003. Epub 2018 Nov 10.
The aims of this study were to determine the species of Parascaris present in foals in Sweden and to establish whether anthelmintic resistance to pyrantel and fenbendazole is present on Swedish stud farms. Ascarid eggs collected from different regions in Sweden were karyotyped and were all identified as Parascaris univalens, characterized by one chromosomal pair. Faecal egg count reduction tests were performed on a total of 142 foals on 9 farms between September 2016 and May 2017. Healthy foals with at least 150 eggs per gram faeces (EPG) were included in the study and treated with oral pastes of pyrantel embonate or fenbendazole according to manufacturer instructions. The efficacy of the drugs was calculated by a Bayesian model using the R package "eggCounts". In accordance with the American Association of Equine Practitioners, parasites were classified as resistant to pyrantel if the reduction in EPG was ≤ 85% and to fenbendazole if the observed efficacy was ≤ 90%. Four of eleven groups treated with pyrantel had an observed efficacy of ≤ 85%, and as many as 43% of the foals treated with pyrantel excreted eggs 10-16 days after treatment. In contrast, one of the six groups treated with fenbendazole had an observed efficacy of ≤ 90%, and only 6% of all foals were excreting eggs 10-16 days after treatment. Since resistance to ivermectin has earlier been shown to be widespread in Parascaris spp. in Sweden it is likely that multiresistant populations are present on Swedish stud farms. This is the first study showing the existence of pyrantel-resistant Parascaris spp. in Europe, and the first ever study where anthelmintic resistance has been shown in P. univalens.
本研究的目的是确定瑞典马驹体内存在的副蛔虫种类，并确定瑞典种马场是否存在对噻嘧啶和芬苯达唑的驱虫抗性。对从瑞典不同地区收集的蛔虫卵进行了核型分析，所有卵均被鉴定为单子宫副蛔虫，其特征是有一对染色体。在2016年9月至2017年5月期间，对9个农场的142匹小马驹进行了粪便虫卵计数减少试验。研究纳入了每克粪便中至少有150个虫卵（EPG）的健康马驹，并根据制造商说明用恩波噻嘧啶或芬苯达唑口服糊剂进行治疗。使用R包“eggCounts”通过贝叶斯模型计算药物疗效。根据美国马医协会的标准，如果EPG降低≤85%，则寄生虫对噻嘧啶耐药；如果观察到的疗效≤90%，则对芬苯达唑耐药。用噻嘧啶治疗的11组中有4组观察到的疗效≤85%，用噻嘧啶治疗的马驹中有多达43%在治疗后10 - 16天排出虫卵。相比之下，用芬苯达唑治疗的6组中有1组观察到的疗效≤90%，所有马驹中只有6%在治疗后10 - 16天排出虫卵。由于此前已表明瑞典的副蛔虫属对伊维菌素广泛耐药，瑞典种马场可能存在多重耐药种群。这是欧洲第一项显示存在对噻嘧啶耐药的副蛔虫属的研究，也是首次在单子宫副蛔虫中显示驱虫抗性的研究。
