阿维菌素在猪和鸡中的应用及多残留检测方法的研究进展

阿维菌素类药物由于其优异的驱虫活性和较高的安全性,被认为是目一类新型、广谱、高效、安全和用量小的兽用抗内、外寄生虫药。文章综述了阿维菌素类药物(包括阿维菌素、伊维菌素、多拉菌素、埃普菌素)在鸡、猪等经济动物中的应用,以及在其动物性食品中的残留检测方法。     

阿维菌素在猪和鸡中的应用及多碳留检测方法的研究进展

阿维菌素类药物由于其优异的驱虫活性和较高的安全性,被认为是目一类新型、广谱、高效、安全和用量小的兽用抗内、外寄生虫药。文章综述了阿维菌素类药物（包括阿维菌素、伊维菌素、多拉菌素、埃普菌素）在鸡、猪等经济动物中的应用,以及在其动物性食品中的残留检测方法。     

阿维菌素类药物简介

阿维菌素（Ａｖｅｒｍｅｃｔｉｎ,又称Ａｂａｍｅｃｔｉｎ）,是由阿佛曼链霉菌发酵产生的一种大环内酯类抗生素,加氢还原后的产物为伊维菌素（Ｉｖｅｒｍｅｃｔｉｎ）。继而,对阿维菌素主核进行改造,又合成了埃普利诺菌素（Ｅｐｒｉｎｏｍｅｃｔｉｎ）、多拉菌素（Ｄｏｒａｍｅｃｔｉｎ）。与阿维菌素相比,后三者比较稳定,并且毒副作用小,因此,主要用于动物驱虫,而阿维菌素主要用作植物杀虫剂。北京中农华威科技有限公司把阿维菌素类药物的研究列为公司的重点项目,集中开发,投入大量的人力和财力,对阿维菌素类药物的生产工艺、…     

液相色谱法测定猪组织中阿维菌素类药物残留量

动物组织中残留的阿维菌素、依维菌素和多拉菌素经乙腈提取,碱性氧化铝固相萃取柱净化后,与荧光衍生化试剂反应,产物用高效液相色谱(荧光检测器)进行检测,实现了阿维菌素类药物的残留分析.本方法在猪组织中测定阿维菌素类药物的检测限为1μg/kg;在猪组织中添加浓度为1、2、5μg/kg时的回收率为55%～75%.     

新型广谱抗生素类驱虫药——塞拉菌素的研究进展

阿维菌素类药物是由链霉菌发酵产生的一组大环内酯类药物,是目前世界上效果最优良、使用最广的一类广谱高效抗寄生虫药,其中已商品化的药物包括阿维菌素(AVM)、伊维菌素(IVM)、多拉菌素(DRM)、埃谱利诺菌素(EPR)及塞拉菌素(SEI)等.塞拉菌素是由基因重组的阿维链霉菌(Streptomyces avermitilis)新菌株发酵而成的一种阿维菌素类抗生素.现将新型广谱抗生素类驱虫药--塞拉菌素的研究进展综述如下.     

阿维菌素类药物在动物性食品中的残留检测研究概况

为了对动物性食品中阿维菌素类残留研究有更深入、全面的了解,并为我国开展阿维菌素类残留检测提供参考,文章综述了阿维菌素类药物(包括阿维菌素、伊维菌素、多拉菌素、依立菌素和莫西菌素)在动物性食品中的单残留和多残留检测方法,包括薄层色谱法、酶联免疫法、高效液相色谱法、液质联用法和液相色谱?质谱?质谱联用法。     

大环内酯类驱虫药物的耐药性

大环内酯类驱虫药物包括阿维菌素类（Avermectins）和杀螨菌素类（Milbemycins）药物。阿维菌素类药物包括阿维菌素（Avermectin）、伊维菌素（Ivermectin）、多拉菌素（Doramectin）和埃普菌素（Eprinomectin）。杀螨菌素类包括莫西菌素（Moxidectin）和杀螨菌素（Milbemycin）。这类药物由于具有广谱高效的驱虫活性和较高的安全性，被认为是20年来驱虫药物研究最杰出的成就。自1981年首次批准登记以来，以后其他同类药物也陆续批准上市。目前，本类药物已在世界多个国家使用，     

液相色谱-串联质谱法检测牛奶中4种阿维菌素类药物残留量的研究

建立了一种可同时检测牛奶中4种阿维菌素类药物(阿维菌素、伊维菌素、多拉菌素和埃谱利诺菌素)残留的液相色谱-串联质谱方法(LC-MS/MS)。牛奶样品经乙腈提取,高速离心去除蛋白质等杂质,C18柱净化。以0.1%甲酸水溶液和0.1%甲酸乙腈溶液为流动相进行洗脱,流速0.4 m L/min,采用基质匹配标准溶液外标法定量。结果表明:阿维菌素、伊维菌素、多拉菌素和埃谱利诺菌素在0.5~100 ng/m L浓度范围内均呈现良好的线性关系,相关系数(R2)均大于0.996;4种阿维菌素类药物的定量限均为0.5μg/kg。阿维菌素在0.5~5μg/kg添加浓度范围内,伊维菌素在0.5~20μg/kg添加浓度范围内,多拉菌素在0.5~30μg/kg添加浓度范围内,埃谱利诺菌素在0.5~40μg/kg添加浓度范围内,回收率为66.4%~120%;批内与批间相对标准偏差均小于20%。该方法具有简便快速、灵敏度高、定性准确,重复性好等特点,可以满足牛奶中4种阿维菌素类药物残留检测的要求。     

阿维菌素类药物的研究及应用

<正> 1 概述由美国默克公司发现并开发成功的阿维菌素(Avermectin)系列产品被誉为继青霉素之后生物类药物的又一次技术革命。阿维菌素是一种生物菌素,作为原药可用于人类医药、兽药、农药,被称为是"三位一体"的药物。其系列产品阿维菌素、伊维菌素的开发应用在国内外已较为普遍,农牧业不断     

埃谱利诺菌素注射剂对绵羊体内外寄生虫的驱杀效果试验

埃普利诺菌素(eprinomectin,EPR)是一种新型的阿维菌素类药物,EPR的抗虫活力及抗虫谱与其他阿维菌素类药物相似,对家畜的绝大多数线虫和螨、虱、蜱、蝇等节肢动物均有很强的杀灭作用,其显著之处为用于奶牛和肉牛时无需休药期。     

兽用阿维菌素类药物剂型研究进展

阿维菌素类药物是目前最优良的一类广谱高效兽用抗寄生虫药物。本文就该类药物的不同剂型及其在兽医临床上的应用和毒理学等方面的研究进展进行了综述     

米尔贝肟的研究进展

米尔贝肟是一种新型的半合成大环内酯类驱虫药,对体内外寄生虫均具有驱杀作用,是公认的具有广谱、高效、安全的驱虫药,特别是对一些伊维菌素敏感的犬相对更为安全。对其产生,理化性质,作用机理,临床应用,安全性及其常见的联合用药等方面进行了综述。     

The detection of anthelmintic resistance in nematodes of veterinary importance

Before revised World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines on the detection of anthelmintic resistance can be produced, validation of modified and new methods is required in laboratories in different parts of the world. There is a great need for improved methods of detection of anthelmintic resistance particularly for the detection of macrocyclic lactone resistance and for the detection of resistant nematodes in cattle. Therefore, revised and new methods are provided here for the detection of anthelmintic resistance in nematodes of ruminants, horses and pigs as a basis for discussion and with the purpose that they are evaluated internationally to establish whether they could in the future be recommended by the WAAVP. The interpretation of the faecal egg count reduction test has been modified and suggestions given on its use with persistent anthelmintics and continuous release devices. An egg hatch test for benzimidazole (BZ) resistance is described. A microagar larval development test for the detection of benzimidazole and levamisole resistance provides third stage larvae for the identification of resistant worms. The sensitivity of these two tests can be increased by using discriminating doses rather than LD(50) values. Details are given of a PCR based test for the analysis of benzimidazole resistance in strongyles of sheep and goats, horses and cattle. Although promising for ruminant trichostrongyles, quantitative determination of gene frequency using real time PCR requires further development before PCR tests will be used in the field. Apart from faecal egg count reduction tests there are currently no satisfactory tests for macrocylic lactone resistance despite the great importance of this subject. Except for treatment and slaughter trials there are no validated tests for fasciolicide resistance or for the detection of resistance in cestodes.     

新一代驱虫抗生素—莫西菌素

莫西菌素同伊维菌素一样 ,是一种目前广泛用于兽医临床的广谱、高效、新型大环内酯类驱虫抗生素 ,是美贝霉素家族中的一员。由于其独特的理化性质 ,在国外 ,已被广泛用于治疗奶牛、猪等动物体内外寄生虫病。文章对莫西菌素的理化特性、作用机制、药动学、制剂、药效、耐药性、毒性、残留等进行了较详细地综述 ,同时也介绍了减少耐药性产生的一些方法 ,为该药能在国内应用提供第一手资料 ,以求为兽医临床用药提供参考     

Anthelmintic resistance in non-strongylid parasites of horses

Since 2002, selected populations of Parascaris equorum in several countries have been reported to survive treatment with macrocyclic lactone (M/L) anthelmintics. Clinical treatment failures are characterized by negligible fecal egg count reduction, but M/L resistance has been confirmed in ascarids by controlled efficacy testing. Resistance was selected by current parasite control practices for foals, which often include exclusive and excessively frequent use of M/L dewormers, thereby minimizing refugia within the host and in the environment. Chemical control of M/L-resistant isolates can be accomplished with pyrimidine and/or benzimidazole anthelmintics, but a few M/L-resistant populations have recently exhibited resistance to pyrantel pamoate as well. Some specimens of Oxyuris equi regularly survive treatment with macrocyclic lactones, but it is uncertain whether this constitutes resistance or merely confirms the incomplete oxyuricidal efficacy of virtually all broad spectrum equine anthelmintics. Variations in other biological parameters of Oxyuris and Parascaris, specifically atypical infection of older hosts and shorter prepatent periods, have been reported anecdotally. These changes may represent genetic modifications that have evolved in parallel with resistance as a result of anthelmintic selection pressure.     

Resistance to moxidectin and abamectin in naturally acquired Ostertagia circumcincta infections in sheep

AIM: To investigate the occurrence of resistance to macrocylic lactone (ML) anthelmintics by Ostertagia circumcincta in lambs on a sheep and cattle property in the North Island of New Zea- land.

METHODS: Thirty lambs were randomly allocated to one of five equal-sized groups, consisting of an untreated control and four treatment groups. The treatments, which were administered at the manufacturer's recommended dose rates, included oral moxidectin, oral abamectin (both at 0.2 mg/kg), an albendazole-levamisole combination, and an albendazole-levamisole-ivermectin combination. Post mortem worm counts were undertaken 7 days after treatment to determine the efficacy of each anthelmintic.

RESULTS: The albendazole-levamisole and albendazole-levam-isole-ivermectin combinations both reduced O. circumcincta burdens to zero whereas for moxidectin and abamectin efficacies of only 72% and 29%, respectively, were recorded.

CONCLUSIONS: These results clearly demonstrated the occurrence of resistance to MLs by O. circumcincta. Although this is not the first occasion where resistance to this anthelmintic family has been detected in this parasite in sheep in New Zealand, it is the first instance that resistance to either moxidectin or abamectin has been reported.     

Moxidectin against ivermectin-resistant nematodes—a global view

SUMMARY Macrocyclic lactone endectocides include two chemically distinct compounds moxidectin, a milbemycin, and ivermectin, an avermectin. The significance of the chemical differences between these compounds in relation to nematode resistance remains to be established. Reported studies indicate that moxidectin at the recommended dose rate of 0.2 mg/kg controls identified strains of nematodes, isolated from sheep and goats, with demonstrated resistance to ivermectin. This reflects the significantly greater potency of moxidectin against the 3 genera of nematodes most commonly involved in anthelmintic resistance, Haemonchus, Ostertagia and Trichostrongylus. Moxidectin, in recommended strategic treatment programmes, should reduce the risk of further development of resistance to the macrocylic lactone endectocides.     

Trichostrongylus colubriformis: in vitro culture of parasitic stages and their use for the evaluation of anthelmintics

Approximately 50 per cent of fourth stage larvae of Trichostrongylus colubriformis taken from the gerbil, Meriones unguiculatus, on day 8 after infection, moulted to the young adult stage when cultured in a complex medium over a seven day period in vitro. Larvae at the late fourth stage of development were highly susceptible to certain benzimidazole, prebenzimidazole, imidazothiazole, pyrimidine, quaternary ammonium, organophosphorus and macrocyclic lactone anthelmintics when any of these were included at very low concentrations in the culture medium. However, few anthelmintics lacking activity against T colubriformis in vivo affected these larvae. An assay employing these larvae in vitro should offer a means for assessing the intrinsic activity of new compounds against T colubriformis in the absence of any complicating host pharmacokinetic factors, and could also be adapted for use as a high capacity preliminary screen. Thus it should now be possible to employ a target parasite at the earliest stages of a lead discovery programme obviating the need to use less relevant free-living nematodes or ones that are natural parasites of rodents.     

Resistance to macrocyclic lactone anthelmintics by Haemonchus contortus and Ostertagia circumcincta in sheep in New Zealand

AIM: To establish the efficacy of oral formulations of ivermectin and moxidectin against naturally acquired abomasal nematode infections on a North Island sheep farm. METHODS: Two controlled slaughter trials were undertaken. In the first, 30 sheep on pasture were randomly allocated on the basis of faecal egg count to 1 of 3 groups, comprising an untreated control group and 2 treatment groups. One treatment group was given a single oral dose of ivermectin and the other a single oral dose of moxidectin, both at the manufacturer's recommended dose rates of 0.2 mg/kg liveweight. Six days after treatment, all animals were slaughtered and their abomasa recovered for worm counting. The second trial, which involved 47 animals, was essentially the same as the first except that, as well as involving the slaughter of 30 sheep from all 3 groups, 6 days after treatment, it also included a further 8 untreated control animals and 9 moxidectin treated animals which were slaughtered 27 days after treatment. RESULTS: At 6 days after treatment, moxidectin was highly effective against all 3 of the abomasal nematodes present. While ivermectin was similarly effective against Trichostrongylus axei 6 days after treatment, it was not effective against either Ostertagia circumcinta or Haemonchus contortus, against which average efficacies of only 63.6% and 61.6%, respectively, were recorded. At 27 days after treatment, moxidectin, was also highly effective against T. axei (97.3% reduction) but not against either H. contortus (71.4% reduction) or O. circumcinta (61.0% reduction). CONCLUSIONS: These results provide the first record of macrocyclic lactone resistance in H. contortus in sheep or in any other host in New Zealand, and the first case where such resistance has been exhibited in more than one parasite species at a time. Although the therapeutic efficacy of moxidectin was high against these resistant H. contortus and O. circumcincta strains, resistance to moxidectin was indicated by its diminished prophylactic activity against them. It is suggested that this reduction in the prophylactic activity of moxidectin is also likely to reduce its apparent current high therapeutic efficacy. CLINICAL RELEVANCE: As well as providing further evidence that it can no longer be automatically assumed that macrocylic lactone anthelmintics will be effective on sheep farms in this country, these findings also present a warning that increasingly complex parasite control options may have to be faced in the future.     

Probable multigeneric resistance to macrocyclic lactone anthelmintics in cattle in New Zealand

AIM: To establish the efficacy of topical formulations of eprinomectin and abamectin against naturally acquired abomasal and small intestinal nematode infections in cattle purchased from a North Island bull-beef property. METHODS: A controlled slaughter trial, involving eighteen 6-8-month-old mixed breed calves, was conducted in May 2002.The animals were randomly allocated on the basis of faecal egg count to one of three equal-sized groups (n=6), consisting of an untreated control group and two treatment groups. One of the treatment groups was treated with a topical formulation of eprinomectin, the other with abamectin. Both anthelmintics were administered as a single topical treatment on an individual liveweight basis, at the manufacturer's recommended dose rates of 0.5 mg/kg. All calves were housed in separate groups with no access to pasture throughout the entire trial and were slaughtered 7-10 days after treatment. RESULTS: Both anthelmintic treatments were highly effective(worm count reduction >98%) against Ostertagia ostertagi, Trichostrongylus axei and Cooperia punctata, but were not effective at reducing worm counts significantly of either Cooperia oncophora or Trichostrongylus longispicularis. Against these latter two parasites, worm count reductions of only 72% and 79%, and 81% and 76%, respectively, were recorded following treatment with eprinomectin or abamectin, respectively (all p>0.05). CONCLUSIONS: These results demonstrate evidence of resistance to macrocyclic lactone anthelmintics by C. oncophora and probably T. longispicularis also. CLINICAL RELEVANCE: As well as perhaps providing the first record of resistance to any anthelmintic by T. longispicularis, the present findings may also represent the first case of resistance to macrocyclic lactone anthelmintics exhibited by more than one parasite species at a time in cattle in New Zealand. KEYWORDS: Eprinomectin, abamectin, macrocyclic lactone, anthelmintic resistance, cattle, Cooperia, Trichostrongylus.