Specific and shared antigenic components of Taenia saginata oncospheres

Taenia saginata oncosphere components were analysed by double diffusion. Antigenic components in saline or detergent (Triton x-100) extracts of T saginata oncospheres were identified using a rabbit polyclonal serum directed against the oncosphere and compared with extracts prepared from the metacestodes and proglottids of T saginata and six other helminths commonly found in cattle. There were seven antigenic components found in the saline extract of the oncospheres, of which six were shared with the metacestodes and proglottids. None of these components was consistently different from those of the other six helminths. However, one of the four components in the detergent extract of the oncospheres was present in neither of the extracts of other stages of T saginata nor in extracts of other helminths. This may be of diagnostic significance.     

The lethal effect of some benzimidazoles on Taenia hydatigena in dogs

The lethal effect of some benzimidazoles on Taenia hydatigena infections in dogs have been compared. Fenbendazole, parbendazole and oxibendazole were more effective than cambendazole and thiabendazole, while coarsely ground mebendazole did not differ significantly from any of them.     

The importance of the New Zealand campaign against Echinococcus granulosus and Taenia hydatigena on the prevalence of Taenia ovis

Extract

An important aspect of the campaign in New Zealand directed against Echinococcus granulosus and Taenia hydatigena is its possible effect on the prevalence of Taenia ovis. The burying of offal to eliminate E. granulosus and T. hydatigena is recommended as being preferable to cooking it and feeding it to dogs. The drastic reduction in the number of European rabbits (Oryctolagus cuniculus) in many districts has also virtually eliminated an important dog-food. Consequently, in addition to commercial products, many farmers are relying on more sheep carcass-meat than previously as a source of dog-food. Other things being equal, conditions would seem ideal for an increase in the prevalence of. T. ovis. This is particularly significant to New Zealand which depends so much on a meat export trade. Damage to this on account of T. ovis could in turn pre- judice a campaign directed against E. granulosus and T. hydatigena.     

催产素和加压素在犬泡状绦虫的免疫组化定位和分布

应用免疫组化ＡＢＣ法研究了催产素和加压素在犬泡状绦虫的定位和分布。在犬泡状绦虫中枢神经系统的脑神经节、２条主要纵神经索和环神经内观察到大量阳性纤维和少量阳性细胞。周围神经系统可见阳性神经纤维在皮层和实质形成神经网。从纵神经索和环神经发出的阳性纤维向生殖器官和皮层的肌肉分布。顶突的小钩之间的肌肉存在阳性反应物,小钩周围有较明显的阳性反应环。生殖器官呈现着色深浅不同的阳性反应,以卵囊—梅氏腺复合体最为明显。结果表明,催产素和加压素的免疫反应物具有相同的分布,它们可能参与虫体的神经内分泌调节。     

Detection of Taenia hydatigena copro-antigens by ELISA in dogs

A sandwich-ELISA was developed for the detection of soluble Taenia hydatigena antigens in fecal samples of dogs. Affinity-purified polyclonal catching antibodies and alkaline phosphatase-conjugated detecting antibodies were employed, which had been obtained from rabbits hyperimmunized with excretory/secretory antigens derived from in vitro maintained adult Taenia hydatigena. The assay allowed the detection of 800 ng T. hydatigena antigen g-1 of feces as a lower limit. Six helminth-free dogs were each infected with 10 T. hydatigena cysticerci isolated from Swiss sheep. After prepatent periods ranging from 57 to 71 days, the dogs started to excrete Taenia eggs and/or proglottids. The ELISA detected Taenia antigens in all six dogs during the prepatent period starting individually between Day 18 and 45 post-infection (p.i.). Anthelmintic treatment of three dogs at Day 95 p.i. resulted in elimination of the cestodes and within the 5 following days in the disappearance of Taenia antigens from feces. The specificity of the assay was evaluated by testing crude antigens derived from helminths or bacteria. Four Taenia species showed cross-reactivity at concentrations of 5 micrograms protein ml-1. Conversely, no cross-reactions occurred with various antigen batches derived from Echinococcus granulosus, E. multilocularis, Dipylidium caninum, Mesocestoides corti, Diphyllobothrium sp., Toxocara canis and bacterial antigens (Salmonella and Escherichia). Moreover, fecal samples from dogs naturally infected with T. canis (n: 13), hookworms (n: 2), Trichuris vulpis (n: 13) and of 10 dogs with mixed infections with these three nematode groups were tested, and results confirmed the high degree of specificity. The Taenia antigens detectable by this ELISA remained immunologically stable in native feces stored at +25 degrees, +4 degrees or at -20 degrees C for at least 5 days.     

Countercurrent immunoelectrophoresis in the diagnosis of Taenia hydatigena cysticercosis in goats

The procedure of countercurrent immunoelectrophoresis in the diagnosis of Taenia hydatigena cysticercosis in goats was carried out for antemortem diagnosis of T. hydatigena cysticercosis in experimentally and naturally infected goats. The antigens of cyst fluid, scolex and membrane of T. hydatigena metacestodes were purified and compared. The sensitivity of the test in experimentally and naturally infected goats was 57.1 and 52.5%, respectively, whereas its specificity using antisera raised against T. solium cysticercosis, hydatid cyst and Fasciola gigantica was 66.7 and 83.4% with partially purified and fractionated antigens, respectively. Of all three antigens, the cyst fluid antigen was found to be most reactive. The test could be employed for antemortem diagnosis of T. hydatigena cysticercosis using purified antigen.     

Efficacy of praziquantel against ovine cysticercosis caused by Taenia hydatigena

Praziquantel was evaluated for its larvicidal activity against naturally or experimentally induced Taenia hydatigena infections in sheep. The major criterion used for assessing efficacy was an estimate of the dose rate required to free 90 per cent of the sheep from infection (ED90) together with a 95 per cent confidence interval. With both light and heavy infections of three-month-old T hydatigena in lambs up to 12 months old, many larvae were killed. The ED90 and 95 per cent confidence limits for six-month-old and aged organisms was estimated to be 13.1 (5.5 to 31.4) mg/kg and 6.1 (2.4 to 15.5) mg/kg, respectively. Equivalent data for the ED50 were 3.4 (1.4 to 8.3) mg/kg and 1.3 (0.3 to 5.4) mg/kg, respectively. It was established that one of the factors involved in the efficacy of praziquantel was associated with the age of the larvae at the time of treatment, the drug being markedly more effective against older than younger organisms.     

泡状带绦虫线粒体部分基因克隆及序列比对分析

采集甘肃兰州市区宠物犬体内两株泡状带绦虫,运用分子生物学方法对其线粒体部分基因进行克隆,并使用基因分析软件Larsergene V7.1进行序列分析,结果发现这两株虫体同源性达到99.6%,与国内的泡状带绦虫广东虫株和甘肃虫株同源性分别达到98.7%和98.4%,鉴定为泡状带绦虫;与其他带科绦虫同源性均高于85%,低于88%。其中,与国内牛带绦虫同源性最高,为88%;与国内巨颈带绦虫同源性最低,只有85.1%。推断不同带科绦虫的cox1基因种间差异明显,在带科绦虫的分类上意义较大。     

The effect of oxfendazole on Echinococcus granulosus and Taenia hydatigena infections in dogs

Trials with oxfendazole carried out on 120 dogs infected with either Echinococcus granulosus or Taenia hydatigena indicated that a single treatment significantly reduced the proportion of dogs infected with tapeworms. Diarrhoea occurred occasionally when the dose rate exceeded 20 mg/kg.     

The HP10 Taenia monoclonal antibody-based ELISA detects a similar protein in the vesicular fluid of Taenia hydatigena

Tropical Animal Health and Production - Diagnosis of Taenia solium cysticercosis in endemic rural communities depends on serological tests, as typically there is no access to imaging facilities....     

Factors regulating tapeworm populations: dispersion patterns of Taenia hydatigena eggs on pasture

Two grazing trials using 'sentinel' lambs were undertaken to measure changes in the availability of eggs within 30 metres of deposition by dogs infected with Taenia hydatigena. In the first trial the experimental pasture was divided into nine equal plots; in the second trial, each of the nine plots was divided into sub-plots. In each trial, infected dogs were placed on the pasture for 10 days. Lambs were then grazed for 10 days immediately, 36 days and 56 days after the dogs had been removed. Changes in the dispersion pattern of the eggs over time and space were assessed by examination of the lambs for cysts at autopsy. In both trials, eggs spread radially within the grazing zone within 10 days, but 36 days after the removal of the dogs, their availability to the lambs was markedly reduced. In the first trial at five weeks, the height of grass (between 3 cm and 15 cm) did not modify egg availability. In both trials, despite differences in rainfall affecting the growth of grass and associated factors similar egg losses occurred.     

Taenia hydatigena: a cause of persistent liver condemnations in lambs

A problem of high levels of liver condemnations which had affected bought-in lambs fattened on a North Yorkshire farm for several years was investigated. Because the farmer spread pig slurry on the land, migrating Ascaris suum larvae were initially suspected as a cause but the investigation eliminated this possibility. Migrating Taenia hydatigena larvae were found in tissue sections and isolated from livers. A combination of parasitological and serological evidence using oncospheral antigen in an ELISA suggested that infection was occurring immediately before the arrival of lambs on the farm, although a source of infection on the farm was also identified. Peak liver condemnations occurred in December-January. Possible reasons for this are suggested and the relevance of these findings to national liver condemnation losses are discussed.     

The effect of nitroscanate on Echinococcus granulosus and Taenia hydatigena infections in dogs.

Trials with nitroscanate carried out on 186 dogs infected with either Echinococcus granulosus or Taenia hydatigena indicated that a single treatment at a dose rate of 1000 mg/kg or two treatments at 250 mg/kg eliminated the former, but a single treatment at 64 mg/kg was sufficient to eliminate the latter. At this dosing schedule, vomiting and diarrhoea occurred, as well as a transient 'tranquillising' effect on some dogs.     

The effect of fospirate on Echinococcus granulosus and Taenia hydatigena infections in dogs.

Trials with fospirate carried out with 170 dogs infected with either Echinococcus granulosus or Taenia hydatigena indicated that a dose rate of 40 mg/kg given on three occasions and 10 mg/kg given on one occasion eliminated each species, respectively. Increasing the dose rat substantially above 40 mg/kg did not reduce the number of treatments required to eliminate all hydatid organisms. Vomiting was observed in some dogs.     

Treatment of Taenia hydatigena infections in dogs with-bunamidine hydroxynaphthoate incorporated in food

Abstract

Extract

Theoretically, the life-cycle of the sheep metacestodes with their strobilate phase in dogs permits combinations of at least three methods of control. These are the prevention of dogs gaining access to larval cestodes, the chemical elimination of the strobilate and or the larval stage in the appropiate hosts, and the immunization of either the definitive or intermediate hosts or both. The first approach using arecoline hydrobromide primarilv as a diagnostic agent has reduced the prevalence of Echinococcus granulosus (Gemmell, 1968 Gemmell, M. A. 1968. The Styx field-trial. A study on the application of control measures against hydatid disease caused by Echinococcus granulosus. Bull. Wld Hlth Org., 39: 73–100.  [Google Scholar]). However, it did not markedly reduce the prevalence rate of Taenia hydatigena and may have been indirectly associated with an increase in that of Taenia ovis.