Mortality in lambs due to enterotoxaemia associated with heavy infestations of Moniezia expansa

Abstract

Extract

Throughout the Hawke?s Bay area of the North Island of New Zealand Moniezia expansa, the common tapeworm of sheep, was extremely abundant in lambs at the end of 1955, following a milder and damper winter and earlier spring than is usual. The numbers of tapeworms were such that workers in the meat-freezing works remarked that they had never before seen so many. Examinations of pasture samples from properties where the lambs were severely infested revealed numbers of the oribatid mites, which are the intermediate hosts of Moniezia, far in excess of the numbers usually encountered. Paddocks at the Wallaceville Animal Research Station, from which pasture samples are examined each week throughout the year, were taken as standard.     

基于ITS基因分析扩展莫尼茨绦虫种系发育关系

为研究扩展莫尼茨绦虫分离株核糖体ITS序列的遗传变异情况,并利用ITS序列探讨扩展莫尼茨绦虫与其它带科绦虫的种群发育关系,本研究利用PCR对扩展莫尼茨绦虫分离株核糖体ITS序列进行扩增、测序及分析。结果表明:16株扩展莫尼茨绦虫分离株核糖体ITS序列长度一致,为1462~1473bP,且分离株与基因库扩展莫尼茨绦虫位于同一大分支,可以与其它带科绦虫有效鉴别。说明ITS序列种内较为保守,种间差异较大,可以作为扩展莫尼茨绦虫的种间遗传变异研究的分子标记。     

An improved drench for the treatment of the tapeworm,Moniezia expansa,in sheep

Extract

The treatment of sheep specifically for tapeworm infestation has generally not been advocated, most authorities maintaining that Moniezia expansa is rarely pathogenic when not associated with concurrent nematode infestations. Most sheep develop a good immunity to these parasites which are usually expelled within three months of the host contracting the infestation. On the other hand, there are numerous scattered references to loss of condition and occasionally to deaths attributed to Moniezia infestation in lambs.     

扩展莫尼茨绦虫引发酶蛋白基因的克隆和cDNA序列分析

分离和鉴定扩展莫尼茨绦虫(Moniezia expansa)新基因,为进一步研究该基因的功能奠定基础。构建扩展莫尼茨绦虫成虫cDNA文库,随机挑取重组阳性克隆进行测序,对部分序列进行引物步移法测序,获取其全长cDNA序列;采用生物信息学等分析技术对该cDNA序列进行开放阅读框(ORF)的寻找、编码氨基酸的推导、核苷酸和氨基酸同源性比较及蛋白质二级结构的初步预测。获得了1个扩展莫尼茨绦虫新基因——引发酶蛋白,全长1269 bp,编码422个氨基酸,属于AE_Prim_S家族。编码蛋白的理论分子质量为47.1598 ku,等电点为4.83。获得了扩展莫尼茨绦虫反应结合蛋白的全长cDNA序列,为该基因功能的试验性鉴定工作奠定基础。     

吡喹酮驱除家养林麝感染的四川莫尼茨绦虫

本文描述了为驱除家养林麝的四川莫尼茨绦虫应用吡喹酮15mg/kg,30mg/kg，服药后11-12小时排出虫体，1个月后虫卵转阴率100%。     

New potential intermediate host of Moniezia expansa Rudolphi, 1810, in Argentina

For the first time in Argentina, it has been shown that oribatids from the genus Ceratozetes Berlese, 1908 (Acarina:Ceratozetidae) have the potential to act as intermediate hosts of Moniezia expansa from sheep. Zygoribatula lata Hammer, 1961 (Acarina:Oribatulidae) was confirmed as a potential intermediate host of M. expansa. A comparative study of the potential effectiveness of both oribatid species as intermediate hosts of M. expansa from sheep was performed.     

扩展莫尼茨绦虫DAZ基因保守结构域所在片段的克隆及原核表达

为了克隆和表达编码扩展莫尼茨绦虫无精症缺失(DAZ)基因,试验根据GenBank中扩展莫尼茨绦虫DAZ基因cDNA序列(登录号为GH291478)设计1对特异性引物,以扩展莫尼茨绦虫组织总RNA为模板,RT-PCR扩增DAZ基因,并克隆到pMD19-T载体中进行序列测定,构建重组质粒pET28a-DAZ,转化BL21(DE3)大肠杆菌感受态细胞,以异丙基-β-D-硫代吡喃半乳糖苷(IPTG)进行诱导表达;利用非变性聚丙烯酰胺凝胶(SDS-PAGE)分析表达产物,通过螯合琼脂糖凝胶FF亲和层析柱对重组蛋白进行纯化。结果表明:重组DAZ基因在大肠杆菌中高效表达,表达的融合蛋白分子量约为14 ku。     

扩展莫尼茨绦虫烯醇化酶基因的原核表达及抗原性鉴定

为表达扩展莫尼茨绦虫(Moniezia expansa)的烯醇化酶(Enolase),本研究采用RT-PCR方法以M.expansa 组织总RNA为模板扩增enolase基因,将其克隆到原核表达栽体pET-28a中,并转化BL21 (DE3)感受态细胞,以IPTG进行诱导表达.SDS-PAGE结果显示表达的重组Enolase约为47 ku.Western blot分析表明,天然蛋白能够被重组表达产物免疫小鼠的血清识别,出现两条免疫印记条带,即天然蛋白以两种形式(约47 ku和40 ku)存在,并具有抗原性,为该蛋白功能研究奠定了基础.     

Tapeworm (Moniezia expansa) and its effect on sheep production: the evidence reviewed

Literature relating to the effects of the tapeworm Moniezia expansa on sheep is reviewed. While there are many claims of adverse effects by this organism, none of these withstand critical scrutiny. The balance of evidence indicates that M. expansa infections are generally harmless, even when the tapeworms are present in large numbers in young lambs, and that there is no justification for treating sheep for M. expansa on the basis of any likely benefit to the health or production of the animals. No published experimental results can be found to support claims that heavy M. expansa infections sometimes exacerbate losses from other causes. Anthelmintics for investigative use, and some aspects of the classification, life history and biology of M. expansa and of its intermediate host are also discussed.     

小尾寒羊扩展莫尼茨绦虫与大肠埃希氏杆菌混合感染的诊治

2005年4～10月,广东省湛江市某养殖场的小尾寒羊出现一种以极度贫血、衰弱、消瘦为主要症状的疾病。笔者通过流行病学调查、病理剖检、血液检验、寄生虫体鉴定及微生物学诊断,确诊为扩展莫尼茨绦虫（M．Expansa）及大肠埃希氏杆菌（E．coli）混合感染。经采取丙硫咪唑、环丙沙星治疗等综合防制措施后,病情得到了有效控制。     

Use of praziquantel to control platyhelminth parasites of fish

Fish are common definitive and intermediate hosts for a variety of parasitic flatworms. In unstressed wild populations, parasitic infections often go unnoticed and are perceived to represent a lesser threat to fish health. In contrast, platyhelminth parasitism of captive fish often results in decreased weight gain and increased mortality which often necessitates chemotherapeutic treatment. The presence of platyhelminth parasites in fish tissues is not only unappealing but in some cases also represents a threat to human health. In veterinary medicine, one of the most commonly used agents with anti‐flatworm activity is praziquantel; yet, no praziquantel products are labeled for use in fish in the United States. Veterinarians may use praziquantel preparations approved for other vertebrate species under the Animal Medicinal Drug Use Clarification Act (AMDUCA). However, such extra‐label use should be informed by scientific evidence including efficacy and tissue residue studies. Herein, we review studies testing the efficacy of praziquantel for treatment of platyhelminthes along with an assessment of routes of administration, pharmacokinetics, and toxicity information.     

Tapeworm (Moniezia expansa) in sheep: anthelmintic treatment studies to assess possible pathogenic effects and production loss in young infected animals in the field

Niclosamide and cupric acetoarsenite were both effective in removing tapeworm (Moniezia expansa) from unweaned lambs. In four trials there was no significant liveweight gain in niclosamide-drenched, compared with undrenched, animals. Post-mortem examination for tapeworm showed that although one lamb contained 200 ml (bulk volume) of strobila, 50% of 49 infected animals contained 50 ml or less. The greatest number of scoleces in one animal was 41, and 65% of lambs contained four or fewer. M. expansa is not indicated as a cause of diarrhoea in lambs.     

Use of praziquantel for treatment of Diphyllobothrium sp infection in a dog

Eggs of a tapeworm, Diphyllobothrium sp (probably D dendriticum), were detected in feces of a healthy, 5-month-old, Siberian Husky. The dog acquired its infection in northern Canada while consuming a diet that included raw salmonid fish. Such fish serve as intermediate hosts for Diphyllobothrium spp. The infection was successfully eliminated by oral administration of a single dose of praziquantel (7.5 mg/kg of body weight.