Swedish University of Agricultural Sciences, Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, P.O. Box 7036, Uppsala, Sweden.
Department of Biomedical Sciences and Veterinary Public Health (BVF), Swedish University of Agricultural Sciences (SLU) Box 7036. 750 07 Uppsala - Sweden.
Vet Parasitol Reg Stud Reports. 2020 Dec;22:100479. doi: 10.1016/j.vprsr.2020.100479. Epub 2020 Oct 7.
In this study, we describe for the first time monepantel (MOP) resistance in gastrointestinal nematodes (GIN) in a Swedish sheep flock. On the farm, which had recurrent problems with Haemonchus contortus infection, the efficacy of most available anthelmintics (AH) in Sweden (i.e. ivermectin, albendazole, levamisole and monepantel), was monitored. This was done with the faecal egg count reduction test (FECRT) on three different occasions between August 2017 and April 2020. Although, MOP was used in ewes for the first time in this herd in October 2018 and then demonstrated to be highly efficacious (100% reduction), MOP-resistant worms (52% reduction) appeared in lambs already in April 2020. Resistance was detected only after two further rounds of treatment of the lambs after weaning. It is assumed that a contributing factor to this extremely rapid development was related to the fact that ewes and lambs treated during the housing period were let out on clean pasture after treatment. The ewes were treated during the housing period 2018 and grazed a clean pasture the following spring. The same ewes were treated a second time after housing 2018. The lambs were grazed with these ewes in summer 2018 and after weaning they were treated and moved to another clean pasture during the fall 2018. Anthelmintic resistance was also confirmed on two occasions to different compounds of ivermectin and once to albendazole, but not to levamisole which was tested twice. In conclusion, this is the first description of triple resistance to AH drugs in GIN of sheep in Sweden.
在这项研究中，我们首次描述了瑞典绵羊群体中胃肠道线虫（GIN）对莫能菌素（MOP）的耐药性。在该农场，反复出现捻转血矛线虫感染问题，我们监测了大多数在瑞典可用的驱虫药（即伊维菌素、阿苯达唑、左旋咪唑和莫能菌素）的疗效。这是在 2017 年 8 月至 2020 年 4 月的三个不同时间点，通过粪便卵计数减少试验（FECRT）进行的。尽管 2018 年 10 月该羊群首次在母羊中使用莫能菌素，效果非常显著（减少 100%），但在 2020 年 4 月，羔羊中已经出现了耐药性线虫（减少 52%）。在对羔羊进行两轮断奶后治疗后，才检测到耐药性。据推测，导致这种极其迅速发展的一个因素是，在圈舍期间接受治疗的母羊和羔羊在治疗后被放到干净的牧场上。2018 年圈舍期间，母羊接受了治疗，第二年春天放牧在干净的牧场上。2018 年圈舍结束后，这些母羊又接受了第二次治疗。2018 年夏天，羔羊与这些母羊一起放牧，断奶后，它们在 2018 年秋季接受治疗并转移到另一个干净的牧场上。还两次证实了对伊维菌素的不同化合物和一次对阿苯达唑的驱虫药耐药性，但对左旋咪唑进行了两次测试，没有耐药性。总之，这是瑞典绵羊胃肠道线虫对驱虫药三重耐药性的首次描述。
