Anthelmintic resistance in cattle nematodes in the US
Anthelmintic resistance in cattle nematodes in the US
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DOI：
10.1016/j.vetpar.2014.03.017
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发表时间：
2014-07-30
影响因子：
2.6
通讯作者：
Gasbarre, Louis C.
中科院分区：
文献类型：
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作者：
Gasbarre, Louis C.
大约10年前，在美国发现了第一例牛胃肠道（GI）线虫大环内酯耐药病例。从那时起，驱虫药耐药性的发生率继续以惊人的速度增加。目前，在一半以上的检查手术中，已证实古柏属和/或血矛线虫属的寄生虫对通用或品牌大环内酯具有耐药性。这两种寄生虫属都能够通过降低食物摄入量和随后的动物生产力来造成经济损失。目前，还没有简单和快速的方法来检测抗驱虫剂的胃肠道线虫。识别身份需要杀牛。最常用的现场检测方法是粪便虫卵计数减少试验（FECRT）。该方法可适用于兽医和生产者的筛选剂，以确定驱虫治疗后寄生虫的清除率低于预期。进一步的研究可以确定鸡蛋数量持续存在的原因。抗蠕虫药耐药性的出现主要是由于开发了非常有效的线虫控制程序，这些程序显着提高了美国养牛业的生产力，但同时也对寄生虫基因组施加了高水平的选择压力。未来的挑战包括开发控制抗蠕虫线虫的程序，但同时导致更可持续的寄生虫控制。目标是保持高水平的生产力，但对寄生虫施加较少的选择压力。减缓耐药性发展的最有效手段之一是同时使用多种类型的驱虫药，每种驱虫药都有不同的作用模式。减少对寄生虫的选择性压力可以通过更有针对性的药物治疗方法来实现，其中生产者的需求通过选择性治疗不同类别的动物而不是在一个地点进行全面治疗来满足。这些计划的实施将因行业部门和个别地点而异。一般来说，饲养场将是最容易制定计划的部门，而堆料机/背景操作将提供最具挑战性的问题。必须解决的一个主要问题是，是否重要的是，寄生虫控制计划是可持续的超时，或者如果制药行业开发新的控制剂的速度足以使可持续性不重要。(C)2014由Elsevier B. V.出版
The first documented case of macrocyclic lactone resistance in gastrointestinal (GI) nematodes of cattle was seen in the US approximately 10 years ago. Since that time the increase incidence of anthelmintic resistance has continued at an alarming rate. Currently parasites of the genera Cooperia and/or Haemonchus resistant to generic or brand-name macrocyclic lactones have be demonstrated in more than half of all operations examined. Both of these parasite genera are capable of causing economic losses by decreasing food intake and subsequently animal productivity. Currently, there are no easy and quick means to detect anthelmintic resistant GI nematodes. Definitive identification requires killing of cattle. The most commonly used field detection method is the fecal egg count reduction test (FECRT). This method can be adapted for use as a screening agent for Veterinarians and producers to identify less than desired clearance of the parasites after anthelmintic treatment. Further studies can then define the reasons for persistence of the egg counts. The appearance of anthelmintic resistance is largely due to the development of very effective nematode control programs that have significantly improved the productivity of the US cattle industry, but at the same time has placed a high level of selective pressure on the parasite genome. The challenges ahead include the development of programs that control the anthelmintic resistant nematodes but at the same time result in more sustainable parasite control. The goal is to maintain high levels of productivity but to exert less selective pressures on the parasites. One of the most effective means to slow the development of drug resistance is through the simultaneous use of multiple classes of anthelmintics, each of which has a different mode of action. Reduction of the selective pressure on the parasites can be attained through a more targeted approach to drug treatments where the producer's needs are met by selective treatment of different classes of animals and not by blanket treatment at a location. The implementation of such programs will vary by the sector of the industry and the individual site. In general, the feedlot will be the easiest sector for developing of programs, while stocker/backgrounder operations will provide the most challenging problems. A major question that must be addressed is whether it is important that parasite control programs to be sustainable overtime, or if the pharmaceutical industry develop new control agents at a rate sufficient to render sustainability unimportant. (C) 2014 Published by Elsevier B.V.