Specificity of scolex and oncosphere antigens for the serological diagnosis of taeniid cestode infections in dogs

Groups of dogs raised free of helminths were monospecifically infected with the common nematodes Toxocara canis, Ancylostoma caninum and Trichuris vulpis. Serums from these dogs, and a group of dogs of unknown history but infected with Dirofilaria immitis and Dipylidium caninum, had levels of antibody to their homologous nematode antigens readily detectable by ELISA. No cross-reactions were apparent when these serums were tested by ELISA using oncosphere antigens of Taenia hydatigena, T. pisiformis and T. ovis, scolex excretory/secretory antigens of T. hydatigena, T. pisiformis and Echinococcus granulosus or protoscolex antigen of E. granulosus.     

Specific antibody responses to Taenia hydatigena, Taenia pisiformis and Echinococcus granulosus infection in dogs

Groups of dogs reared free of both nematodes and cestodes were infected with Taenia hydatigena, Taenia pisiformis or Echinococcus granulosus. After infections with the Taenia spp became patent, dogs were purged to remove the worms. They were later reinfected and the second infections again removed by purging after patency. A group of 3 uninfected worm free dogs was kept as age-matched controls. The dogs were bled at intervals of 5 days and their serums tested for antibodies using the enzyme-linked immunosorbent assay (ELISA) with excretory/secretory (ES) antigens collected during in vitro incubation of evaginated scoleces (scolex ES antigen) and oncosphere antigens. Antibodies to scolex ES antigen were detected by 3 weeks after infection with each cestode species whereas antibodies to oncosphere antigen were not detected until about one week after eggs were found in the faeces of the infected dogs. Antibody responses to both oncosphere and scolex ES antigens decreased rapidly following removal of the worms by purging. Uninfected control dogs were invariably negative to both oncospheral and scolex ES antigens. There were cross-reactions between the serums from dogs infected with T. pisiformis and T. hydatigena when tested with scolex ES antigens, but oncospheral antigens showed a high degree of species specificity. Scolex ES antigens from E. granulosus were compared with those prepared from T. hydatigena and T. pisiformis for their ability to discriminate between antibodies in serums collected from dogs 31 and 32 days after infection with 100,000 protoscoleces of E. granulosus or dogs infected with Taenia spp.(ABSTRACT TRUNCATED AT 250 WORDS)     

Efficacy of a drug combination of praziquantel, pyrantel embonate, and febantel against helminth infections in dogs.

Tablets containing praziquantel, pyrantel embonate, and febantel were tested for efficacy against helminths in dogs. A single treatment with this drug combination gave 100% reductions in Toxocara canis and Taenia hydatigena in experimentally induced infections in dogs. In dogs with naturally acquired infections, treatment gave > 97 to 98% reductions in fecal egg counts attributable to Toxascaris leonina, T canis, and Uncinaria stenocephala. Efficacy against Trichuris vulpis was > 92%.     

异源性抗原抗猪囊尾蚴感染的研究

本文报道了泡状带绦虫活化六钩蚴的超声裂解抗原可以诱导猪体产生抗猪带绦虫攻击感染的交叉保护作用。猪囊尾蚴匀浆抗原也使猪体产生了较强的抗猪带绦虫攻击感染的保护作用。泡状带绦虫六钩蚴超裂抗原免疫组与猪囊尾蚴匀浆抗原免疫组的保护情况是相似的,这表明异源免疫也可使猪体产生较好的抗猪囊尾蚴感染的免疫。由于制备异源性抗原的泡状带绦虫能够从狗的体内获得,因此在体外培养猪带绦虫未获成功之前可以解决从人体获取猪带绦虫的困难。     

犬泡状带绦虫潜在前期研究与PCR鉴定

为查明猪细颈囊尾蚴在犬体内发育为成虫后节片的最早排出时间（潜在前期）,将新鲜的猪细颈囊尾蚴经口感染6只无绦虫犬后,采用反复水洗沉淀法检测感染犬粪中排出的第1个绦虫节片,并用特异PCR方法鉴定其种属。结果显示,6只感染犬的潜在前期分别为60、63、65、69、72、73 d。同时,特异性PCR结果显示其序列与Genbank收录的泡状带绦虫序列的相似性为99%,确认犬排出的节片为泡状带绦虫。本研究为建立泡状带绦虫在宿主体内的发育模型提供了一定的基础资料。     

Haematological and serological data from dogs raised worm-free and monospecifically infected with helminths

Pups free from helminth infection were obtained by treating the bitch prior to parturition, and the bitch and her pups after whelping, with oxfendazole and praziquantel. They were then housed in an area free from contamination with helminth eggs. Freedom from infection was confirmed by necropsy examinations and by serological tests using the Enzyme Linked Immunosorbent Assay (ELISA). Groups of pups were infected with Toxocara canis, Echinococcus granulosus, Taenia ovis, T. pisiformis and T. hydatigena and bled at 5-day intervals. Haematological examinations and measurement of serum proteins were performed on blood samples obtained throughout 30 days of infection. Levels of serum proteins were not significantly altered in any infection. Pups infected with T. canis showed a marked increase in numbers of circulating eosinophils during the phase of larval migration through the liver and lungs; they also showed marked antibody responses to T. canis larval ES antigen. Haematological values were not significantly altered in any other pups.     

Comparative immunoelectrophoretic analysis of Echinococcus granulosus, Taenia hydatigena and Taenia pisiformis cyst fluid antigens by hyperimmune rabbit sera.

Cyst fluid antigens of Echinococcus granulosus, Taenia hydatigena and T pisiformis were examined by electrophoresis using homologous and heterologous hyperimmune rabbit sera to these antigens. While arc 5 forming antibodies were identified in sera from rabbits immunised with E granulosus and T hydatigena cyst fluids, antibodies responsible for forming precipitating antigen B band were detected in rabbit antisera to E granulosus, T hydatigena and T pisiformis antigens. T hydatigena cyst fluid appears to contain antigen similar to E granulosus antigen 5 and probably antigen B while T pisiformis cyst fluid has mainly an antigen close to hydatid antigen B.     

Cross-reactions between crude antigens of larval Taenia solium (Cysticercus cellulosae) and other helminths of pigs

A crude antigen extract of larval Taenia solium was shown by immunodiffusion (ID) and immunoelectrophoresis (IEP) to cross-react with rabbit antisera against pig serum proteins and larval T. hydatigena, and by enzyme-linked immunosorbent assay (ELISA) with antisera against pig serum proteins, Fasciolopsis buski, larval T. hydatigena, hydatid cyst, Hymenolepis diminuta and Dipylidium caninum. Immunoblotting demonstrated that the crude antigens extract contained epitopes of pig serum proteins of 48 and 66 kDa. The crude extract also contained a subunit of antigen B (95 kDa) which was also found in T. hydatigena and H. diminuta. Immunoperoxidase and indirect immunofluorescence studies showed that cross-reacting antigens were distributed mainly on the tegument of T. solium.     

A study on intestinal helminthes of dogs, foxes and jackals in the western part of Iran

Human infection especially with helminth parasites is an emerging health issue, as the human environment is increasingly shared with infected animals, either pets or wild life. In this survey, the intestinal content of 83 stray dogs, 22 red foxes and 10 golden Jackals collected from the West Azarbaijan, Kordestan and Kermanshah provinces in the west of Iran, were studied for the presence of helminth parasites. The percentage of different species recovered from these animals is listed as follows: From stray dogs: Toxocara canis (6.02%), Toxascaris leonina (32.53%), Ancylostoma caninum (3.61%), Oxynema sp. (1.35%), Rictularia affinis (12.05%), Taenia hydatigena (53.01%), Taenia ovis (7.23%), Taenia multiceps (4.82%), Echinococcus granulosus (13.25%), Dipylidium caninum (38.55%), Mesocestoides lineatus (26.50%) and Macracanthorhynchus hirudinaceus (4.82%). From red foxes: T. canis (4.54%), T. leonina (31.82%), A. caninum (4.54%), Uncinaria stenocephala (13.64%), Oxynema sp. (9.09%), R. affinis (54.54%), Strongyloides sp. (4.54%), Physaloptera sp. (4.54%), T. hydatigena (9.09%), E. granulosus (4.54%), D. caninum (9.09%), M. lineatus (81.82%), Joyeuxiella pasqalei (27.27%), Diplopylidium nolleri (4.54%), M. hirudinaceus (22.72%) and Macracanthorhynchus sp. (9.09%). From golden jackals: T. canis (10%), T. leonina (30%), R. affinis (50%), T. hydatigena (10%), D. caninum (20%), M. lineatus (70%), J. pasqalei (30%.), Alaria canis (10%), M. hirudinaceus (30%) and Macracanthomynchus sp. (10%).     

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.     

兰州市门诊宠物犬猫胃肠道寄生虫感染情况调查

为摸清兰州市宠物犬、猫胃肠道寄生蠕虫的感染情况,于2008年6月～2009年5月通过肛门直接收集,或采集自然排出的粪便,册沉淀法和漂浮法相结合对256只犬、57只猫进行了虫卵或虫体检查。结果显示,256只犬中有48Z犬感染胃肠道寄生虫,感染率18．75％,主要检出犬弓首蛔虫、泡状带绦虫、犬钩虫、犬复孔绦虫、细粒棘球绦虫、华支睾吸虫6种虫卵或／和虫体;57只猫中有14只感染胃肠道寄生虫,感染率24．56％,主要检出犬复孔绦虫、华支睾吸虫、泡状带绦虫3种虫卵或／和虫体。     

Estimation of canine intestinal parasites in Córdoba (Spain) and their risk to public health

The prevalence of gastrointestinal parasites in dogs was studied in the province of Córdoba (southern Spain), with special attention to those parasites that can be transmitted to man. The experiment was completed with the examination of soil samples from public parks and city gardens. The study was carried out over a population of 1800 animals entered in the Control Animal Centre (CECA) by coprological methods, and within this group, 300 dogs were sacrificed and necropsied. The prevalence of any intestinal parasitic infection was 71.33%. The following parasites of the gastrointestinal tract were recorded: Isospora canis (22%), Isospora (Cystoisospora) spp. (10.22%), Sarcocystis (2.5%), Hammondia/Neospora (1.94%), Giardia canis (1%), Dipylidium caninum (13.2%), Taenia hydatigena (7.66%), Taenia pisiformis (4%), Uncinaria stenocephala (33.27%), Toxascaris leonina (14.94%), Toxocara canis (17.72%) and Trichuris vulpis (1.66%). Related to public health, it is important to point out the presence of T. canis only in puppies younger than one year and Uncinaria, more frequent in adult dogs. Soil samples of parks revealed the presence of eggs of Toxocara, and it suggests the existence of real risk for human infection.     

Evaluation of an antigenic fraction of Taenia hydatigena metacestode cyst fluid for immunodiagnosis of bovine cysticercosis

An antigenic fraction (ThFAS) isolated from Taenia hydatigena metacestode cyst fluid was used in an ELISA to detect antibodies to T saginata in experimentally and naturally infected cattle. In 10 calves given 1,000 to 100,000 T saginata eggs (20% to 60% viability), IgG and IgM antibodies were detected in all the calves by post-inoculation week 3. Immunoglobulin G antibody values remained increased until calves were slaughtered at post-inoculation weeks 13 to 26. Six naturally infected calves (determined by postmortem examination) were considered positive, using the ELISA. Shared antigens were demonstrated between ThFAS and T saginata and T crassiceps; there were no shared antigens between ThFAS and Haemonchus contortus or Fasciola hepatica. Specific lectin binding to ThFAS indicated the presence of glycoconjugates. Immunoblot analysis indicated that a low molecular weight polypeptide (10,000 Mr) bears the immunodiagnostic antigen.     

Prevalence of helminth parasites of dogs in Lusaka,Zambia

Eighty-five dogs were examined and the numbers and types of helminth parasites found were recorded. Forty per cent of the dogs were infected with one or more helminth parasites. The most prevalent helminths were the cestodes Dipylidium caninum (24.7%) and Taenia hydatigena (17.64%). Infections were evenly distributed with sex of host. Juvenile dogs were more commonly infected with Toxocara canis than adults whereas all other helminths were found more in adult dogs.     

The survival in sheep and infectivity to dogs of Taenia hydatigena and T. ovis in sheep

Lambs were reared from birth to 3 months of age on pasture contaminated with the eggs of either Taenia hydatigena or Taenia ovis. They were necropsied at 3, 6, 9 or 12 months. Almost all larvae that were viable at 3 months continued to survive throughout the experiment. Larvae of T. hydatigena were infective to dogs at 3 months, whereas those of T. ovis required more than 3 months to reach the infective stage.     

Detection of Echinococcus granulosus coproantigens in faeces from naturally infected rural domestic dogs in south eastern Australia

OBJECTIVE: To investigate the occurrence of Echinococcus granulosus in rural domestic dogs in farming areas around Yass, New South Wales, and Mansfield and Whitfield, Victoria. DESIGN: Faeces were collected per-rectally from farm dogs voluntarily presented by their owners in four farming districts in New South Wales and two in Victoria. PROCEDURE: Faeces were collected in the field, an extract prepared from each sample and E granulosus coproantigens detected in an ELISA. Farmers were also questioned about their dog feeding and worming practices. RESULTS: Echinococcus granulosus coproantigens were detected in 99 of 344 dogs (29%) from 95 farms in south eastern New South Wales and 38 of 217 dogs (17.5%) from 43 farms in Victoria. Cross-reactions between E granulosus coproantigen trapping antibody and coproantigens in faeces from dogs monospecifically infected with other species of intestinal helminthes (Taenia ovis, T hydatigena, T pisiformis, Spirometra ericacei, Dipylidium caninum, hookworm, Toxocara canis, Trichuris vulpis) were not evident. Dietary and worming data revealed many owners fed raw meat and occasionally offal from domestic livestock and wildlife to their dogs and few owners wormed their dogs frequently enough to preclude the chance of patent E granulosus being present in their dogs. CONCLUSION: Echinococcus granulosus occurs commonly in rural dogs in south eastern Australia and an education program promoting the public health importance of responsible management of rural dogs is urgently needed.     

Risk of Toxocara canis eggs in stray and domestic dog hair in Egypt

The aim of the study was to assess whether the hair of stray and domestic dogs in Egypt was contaminated with the eggs of the zoonotic parasite Toxocara canis, and also to identify risk factors for T. canis for contamination. Paired samples of hair and feces were collected from 53 stray and 47 domestic dogs, and hair samples were obtained from a further 11 stray and 9 domestic dogs. All samples were examined to identify T. canis eggs and, if eggs were found, their maturation stage. Eggs were identified in 26.6% of stray and 10.7% of domestic dog's hair samples. A significantly increased risk of embryonated T. canis eggs in hair samples was found in stray dogs (p=0.04), stray dogs had 3.18 (95% CI: 1.04-9.74) times the odds of having T. canis eggs present compared with domestic dogs. There was also a significant difference (p=0.02) between the mean quantity of eggs per gram in stray (77.6±6.54) and domestic (48.7±6.65) dog's hair. Fecal examination found a T. canis egg prevalence of 35.8% and 21.3% in stray and domestic dogs, respectively. As no domestic dogs which were positive from hair samples had negative fecal samples, this indicates that the presence of T. canis eggs in hair is probably due to self contamination. Two stray dogs had positive hair samples but negative fecal samples indicating that contamination may also be environmental. As both non-embryonated and embryonated T. canis eggs were found in the hair of domestic dogs, direct contact with dogs may be a potential risk factor for transmission of T. canis eggs to humans.     

Evaluation of tongue inspection and serology for diagnosis of Taenia solium cysticercosis in swine: usefulness of ELISA using purified glycoproteins and recombinant antigen

Evaluation of serology using glycoproteins (GPs) purified by preparative isoelectric focusing (pH 8.8) and recombinant chimeric antigen (RecTs) of Taenia solium was carried out using (1) blood samples on filter papers from pigs infected with different doses of eggs of T. solium in Mexico, (2) serum samples from pigs found infected naturally in Vietnam and Ecuador and (3) serum samples from pigs suspected to be infected with T. solium by tongue inspection in Tanzania. Antibody responses (IgG) were detectable in experimentally infected pigs confirmed harbouring 16 or more cysts at necropsy from 30 days after egg inoculation. One of three pigs naturally infected and harbouring 2.5 cysts/kg muscle and most of pigs harbouring=5.0 cysts/kg were also seropositive by ELISA. Although pigs may be infected with other taeniid species such as Taenia hydatigena, pigs harbouring this parasite were negative in ELISA. Approximately, 76 and 78% of sera from pigs having nodule(s) in the tongue (positive tongue inspection) were serologically positive by both ELISA and immunoblot, respectively. Furthermore, approximately 34 and 18% of sera from pigs having no nodules in the tongue (negative tongue inspection) were also seropositive by ELISA and immunoblot, respectively. ELISA using the two antigens was more sensitive than immunoblot and reliable for differentiation of pigs infected with cysticerci of T. solium from those either uninfected or infected with other taeniid species. Pigs without nodule by tongue inspection should be checked serologically in endemic areas.     

Gastro-intestinal helminths of domestic dogs in the Republic of South Africa

Of the gastro-intestinal helminths found in 1 063 dogs from different parts of the country, Dipylidium caninum, the most prevalent cestode, occurred in 19,7% of the animals. Echinococcus granulosus was present in 10 dogs, 8 of which were from urban areas, and Taenia hydatigena in 69 dogs. Taemia multiceps was recovered from dogs only in the Cape Province and the Orange Free State. Toxocara canis was present in 81 of the necropsies carried out on 253 dogs from the Pretoria municipal area, while Ancylostoma spp. were present in 175 dogs. In the Pretoria area Ancylostoma caninum (11,9%) was more prevalent than Ancylostoma braziliense (6,2%).     

A survey of gastro intestinal helminth parasites of stray dogs in Zaria, Nigeria.

A survey of helminth parasites in stray dogs was carried out in the Zaria area. Out of 180 dogs examined 65.6 per cent (118/180) were found positive for Ancylostoma caninum, while Toxocara canis and Trichuris vulpis were detected in 41.1 per cent (74/180) and 13.9 per cent (25/180) respectively. Other helminth parasites found Taenia ovis 35 per cent (63/180) Taenia hydatigena 67.8 per cent (122/180), Echinococcus granulosus 0.006 per cent (1/180) and Dipylidium caninum 97.8 per cent (176/180).