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PubMed1998

[Iso-enzyme study of Echinococcus granulosus protoscoleces in Algeria].

The purpose of this study is to identity the strains of Echinococcus granulosus the causative agent of unilocular hydatid in Algeria--a high endemic area. For this, the authors established a simple and reproductible electrophoretic techniques for iso enzyme analysis of protoscoleces. The enzymatic extracts of protoscoleces from various hosts and localisations of hidatic cystic analysed by these electrophoretic techniques showed variable electrophoretic profils witness the existence of various strains.

Algeria↗
PubMedDate not supplied

[Efficacy evaluation of epsiprantel (Cestex) against Echinococcus mutilocularis in dogs and cats].

Helminth-free dogs and cats were experimentally infected with protoscoleces of Echinococcus multilocularis and used in controlled trials for efficacy evaluation of the cestodicide epsiprantel. In two separate trials each 4 dogs were treated at day 20 post infection (p.i.) with average oral dosages of 5.1 (4.9-5.3) and 5.4 (5.2-5.8) mg/kg body weight (b.w.) epsiprantel, respectively, and necropsied at day 24 p.i. Among each 4 dogs of the two untreated control groups all animals were infected and had high intestinal worm burdens with averages of 33.575 and 100.725 E. multilocularis specimens per animal (individual worm burdens in group Ib 59,500-149,800, group IIb 20,500-43,200); in the two groups of treated dogs the average worm burdens were reduced by 99.6 and 99.9%. Among 8 treated dogs 4 were helminth-free, the other 4 had residual worm burdens (10-70 in 3 dogs, 1480 in 1 dog). In each 5 cats single oral treatments with average doses of 2.7 (2.7-2.8) and 5.5 (5.5-5.5) mg/kg b.w. epsiprantel were 100% effective against E. multilocularis 20 days p.i. and eliminated the worm burdens from all 10 animals. In the untreated group of 5 cats the average worm burden was 2864 per animal (individual worm burdens 20-6830). Side effects of the drug treatment were not observed. The results of the study show that in single therapeutic dosages recommended by the producer (dogs 5.5 mg, cats 2.75 mg/kg b.w.) epsiprantel eliminates E. multilocularis to over 99% or completely, but residual worm burdens may persist in some animals.

Animals↗
PubMed2001

[Increase in the prevalence of Echinococcus multilocularis infection in red foxes in Lower Saxony].

Echinococcus multilocularis is a tapeworm having carnivores as final hosts, the red fox in particular, dog and cat less frequent. Its two host life cycle consists of a larval cycle which predominantly takes place in the liver of rodents such as mice but it can also develop in musk rats as intermediate hosts. Man can also be infected and serves as a wrong intermediate host. He develops an alveolar echinococcosis which usually ends lethal without medical treatment. The prevalence of E. multilocularis among 5.365 red foxes in Lower Saxony was monitored from 1991 to 1997. The data were analysed using spatial epidemiological methods. This evaluation is based on a significance test which was applied to the parameters of spatial autoregressive regression models (CAR) fitting to the data of two successive sampling periods from 1991-1994 and 1994-1997. The mean prevalence (spatial median) increased from 6% to 11%. The results of this epidemiological study which was restricted to Lower Saxony support for the first time the earlier reported assumption that the prevalence of foxes infected with E. multilocularis has risen in Europe in the last decade. The reasons for this development are still unknown.

Animals↗
PubMed2001

In vitro effects of isoprinosine and a dipeptide methyl ester on Echinococcus multilocularis protoscoleces.

A protoscoleces/vesicles in vitro maintenance test with assessment of viability by eosin exclusion was used to evaluate the quantitative and qualitative activities of isoprinosine, its active component inosine and the dipeptide methylester L-Phe-Phe-OMe on isolated protoscoleces of Echinococcus multilocularis for 24 and 48 h. Isoprinosine and inosine showed dose- and time-dependent activity, the latter displaying a more rapid effect than the former. A high activity was shown with L-Phe-Phe-OMe, when compared to praziquantel. Ultrastructural alterations were much more striking with L-Phe-Phe-OMe, with an effect similar to that of praziquantel, whereas the chemotherapeutic activity of inosine and isoprinosine appeared to be directed against a metabolic target, with a lethal effect not immediately visible at the ultrastructural level. Thus, the previously reported in vivo activities of these drugs result largely from a direct effect on the parasite.

Animals↗
PubMed1975

Isolation of the most immunoreactive antigenes of echinococcus granulosus from sheep hydatid fluid.

This paper describes a simplified procedure for obtaining purified Echinococcus granulosus antigens from sheep hydatid fluid by using affinity chromatography on concanavalin A-Sepharose. The presence of two "major" antigens (4 and 5) was confirmed. Antigen 5 was isolated by preparative polyacrylamide gel electrophoresis. Antigen 4, eluted by diffusion from the gel, was seen to be "contaminated" by antigen 5 and was isolated by using anti-5 Sepharose-linked serum. These two major antigens were then tested separately against the sera of hydatidosis patients by using very simple immunolgic tests. The best results were obtained in passive hemagglutination with antigen 4. Antigen 4 is the most immunoreactive parasitic antigen; antibodies against it were found in the sera of all hydatidosis patients showing positive reaction. Apart from the direct use of this antigen in serologic tests, it appears possible to standarize the most frequently used and commerically available antigenic materials by titrating this component.

Animals↗
PubMed2001

Comparison of the antigenicity of protoscoleces and microvesicles of Echinococcus multilocularis prepared from rats.

Rats are known to be relatively resistant to infection with Echinococcus multilocularis. However, when rats are inoculated with the parasite tissues, E. multilocularis proliferates slowly at first but after 6 months the cysts increase in size considerably and contain large numbers of protoscoleces. As rats survive for 18 months or longer, approximately 100 ml of packed protoscoleces can be produced from each rat. A comparison of the antigenicity of the protoscoleces and microvesicles by immunoblot methods showed that both Em18 and Em16 are shared components between both protoscoleces and microvesicles, although the latter have some additional antigenic components. In antigens prepared from protoscoleces, the banding patterns around Em18 were much simpler than those from microvesicles. Therefore, for serodiagnosis of E. multilocularis, antigens should be carefully prepared from protoscoleces rather than microvesicles from the rat.

Animals↗
PubMed2002

Prevalence and intensity of Echinococcus multilocularis in red foxes (Vulpes vulpes schrencki) and raccoon dogs (Nyctereutes procyonoides albus) in Otaru City, Hokkaido, Japan.

A survey was done in an attempt to investigate the epidemiological status of Echinococcus multilocularis in red foxes and raccoon dogs in Otaru city from June to September 1999. Sixty-seven red foxes (Vulpes vulpes schrencki) and 13 raccoon dogs (Nyctereutes procyonoides albus) were captured, and postmortem examinations were conducted with them. Thirty-eight red foxes (56.7%) and 3 raccoon dogs (23.1%) were found to be infected with E. multilocularis. The total biomass of E. multilocularis in all infected red foxes and raccoon dogs were 2,817,000 and 1,515 worms, respectively. Nine of the infected red foxes harboring more than 100,000 worms accounted for 90.6% of the total biomass. No significant differences in the prevalence were observed between male and female, and juvenile and adult. However, the worm burden was higher in juvenile than in adult foxes. In one of the infected raccoon dogs, mature worms and eggs of E. multilocularis were found in the intestine and fecal sample, respectively. This result suggested that the raccoon dogs are probably playing a small role in the egg contamination of the environment. The validity of coproantigen ELISA for diagnosis of foxes was confirmed by comparing the results of autopsy, egg examination and coproantigen ELISA using rectal fecal samples.

Animals↗
PubMed1998

[Comparative observation on experimental infection with Echinococcus multilocularis in Cricetulus Migratorius and Meriones meridianus].

AIM: To search for an animal model with higher susceptibility to Echinococcus multilocularis and shorter experimental period. METHODS: Cricetulus migratorius, Meriones meridianus and NIH mice were experimentally infected with protoscolices of E. multilocularis and were autopsed at different times after their infection. The development of E. multilocularis in these three species of rodents was observed and compared. RESULTS: The average wet cyst weight and the ratio of cyst weight to body weight on the 91st day after infection were 15.0 +/- 2.1 g and 32.3% for C. migratorius, 3.3 +/- 1.1 g and 6.9% for M. meridianus, 0.6 +/- 0.6 g and 2.4% for NIH mice; and the corresponding figures on the 188th day after infection were 11.8 +/- 2.7 g and 21.7% for C. migratorius, 8.1 +/- 5.1 g and 15.4% for M. meridianus and 8.4 +/- 8.3 g and 26.7% for NIH mice, respectively. On the 91st day, matured protoscolices were found in C. migratorius and M. meridianus, whereas NIH mice had matured protoscolices on the 188th day after infection. CONCLUSION: C. migratorius has higher sensitivity to E. multilocularis infection than the other two species of animals as manifested by high infection rate, well-developed vesicles and rapid growth speed. C. migratorius proved to be an ideal experimental animal for E. multilocularis.

Animals↗
PubMedDate not supplied

[The occurrence of Echinococcus multilocularis in red foxes in lower Saxony: identification of a high risk area by spatial epidemiological cluster analysis].

There is considerable interest in the spatial distribution of Echinococcus multilocularis in red foxes (Vulpes vulpes L.), because this parasite causes the zoonoses of alveolar echinococcosis which is potentially of high fatality rate. High risk areas are known from France, Switzerland and the Swabian Alb in Germany for a long time. In this work, the spatial scan statistic is introduced as an instrument for identification and localisation of high risk areas, so called disease clusters in spatial epidemiology. The use of the spatial scan statistic along with data about the distribution of the parasite in 5365 red foxes in Lower Saxony, that were collected during 1991 to 1997, led to the identification of another high risk area. The relative risk for this disease cluster is approximated by RR = 5.03 (CI0.95(RR) = [4.27; 6.58]) for the period of 1991 to 1994 and by RR = 4.45 (CI0.95(RR) = [3.53; 5.59]) for the period of 1994 to 1997, respectively.

Animals↗
PubMed2003

Short report: Echinococcus granulosus from Xinjiang, PR China: cDNAS encoding the EG95 vaccine antigen are expressed in different life cycle stages and are conserved in the oncosphere.

The EG95-based vaccine protects sheep from infection with the dog tapeworm Echinococcus granulosus. The EG95 encoding gene is a member of a multigene family, several members of which are expressed in the oncosphere, believed to be the target of immunity induced by the vaccine. E. granulosus exhibits extensive intraspecific (strain) variation, and variability of the eg95 gene in different isolates of E. granulosus may directly impact the effectiveness of the EG95-based vaccine. We analyzed the eg95 gene from E. granulosus collected in Xinjiang, in northwest China, where hydatid disease is hyperendemic. The gene is expressed in oncospheres, protoscoleces, and immature and mature adult worms, and the eg95 gene family was shown to comprise two basic sequence types. Very limited sequence variation was evident in the EG95 protein from oncospheres. This high degree of sequence conservation predicts that the vaccine will continue to be effective in China and elsewhere.

Amino Acid Sequence↗
PubMed2003

Isolation and characterization of microsatellites from the tapeworm Echinococcus granulosus.

The Echinococcus granulosus genome was searched for microsatellites using 8 different repeated oligonucleotides as probes (GT15, CT15, AT15, CG15, CAT10, CAA10, CGG10 and CATA10). Southern blot experiments revealed that DNA regions containing GT, CAA, CATA and CT repeats are the most frequent in the E. granulosus genome. AT and CG probes showed no hybridization signal. Two loci containing CA/GT (Egmsca1 and Egmsca2) and 1 locus containing GA/CT (Egmsga1) repeats were cloned and sequenced. The locus Egmsca1 was analysed in 73 isolates from Brazil and Argentina whose strains were previously characterized. Brazilian isolates from cattle strain and Argentinean isolates from camel strain were monomorphic and shared the allele (CA)7. Argentinean isolates of sheep and Tasmanian sheep strains shared 2 alleles [(CA)8 and (CA)10] with Brazilian isolates of sheep strain. The allele (CA)11 was found only in Brazilian isolates of sheep strain at a low frequency. The Brazilian and the Argentinean sheep strain populations were tested for the Hardy-Weinberg equilibrium, and only the former was in agreement with the expectations. No polymorphism was found among individual protoscoleces from a single hydatid cyst, validating the utilization of pooled protoscoleces from 1 cyst, grouped as an isolate, in population studies. This work describes for the first time the isolation and characterization of microsatellites from E. granulosus.

Animals↗
PubMed2003

[Study on the level of specific IgG, IgG1 and IgE during anaphylactic shock in sheep induced by Echinococcus granulosus].

OBJECTIVE: To investigate the change of specific antibodies IgG, IgG1 subclass and IgE in sheep infected with Echinococcus granulosus (E. g) during anaphylactic shock, and to observe antigen B reactivity against IgG antibody in E. g-infected sheep. METHODS: Antigen B and crude antigen were prepared with E. g cyst fluid (EgCF) from infected sheep. The enzyme-linked immunosorbent assay(ELISA) was used for detecting the level of specific IgG, IgG1 and IgE during anaphylactic shock in sheep induced by E. g. RESULTS: The level of specific IgG, IgG1 and IgE was significantly higher in the infected sheep after 6 months than that of the uninfected control group (P < 0.01). The IgE level decreased rapidly after anaphylactic shock induced, especially when the sheep was dying. Following an antigen challenge the sheep showed a general decrease in total IgG and IgG1 subclass. The total IgG showed a slight change at the beginning, followed by a decrease 1 h after challenge. The decrease of IgG1 subclass was more significant than the total IgG in 40 min after challenge injection. The positive rate was 91% for antigen B and 32% for crude antigen of EgCF against IgG antibody in E. g-infected sheep. CONCLUSION: The specific IgE plays a major role in the anaphylactic shock, while IgG and IgG1 antibodies are also important. Antigen B derived from sheep E. g cyst fluid appears to be useful in serodiagnosis of and monitoring on the infection status in sheep.

Anaphylaxis↗
PubMed1992

Immune response to Echinococcus multilocularis infection in the mouse model: a review.

Echinococcus multilocularis is a cestode helminth which, along with E. granulosus, E. oligarthus and E. vogeli is a causative agent of hydatid disease in man. In the intermediate host (including man), cysts formed by the metacestode (larval stage) develop in the internal organs, causing functional impairment which often leads to the death of the host. In this review larval E. multilocularis infection in mice, the most popular experimental intermediate host, is examined, and the immune response to the organism is described in detail. Evidence is presented which suggests that cell-mediated immunity (CMI) plays a large role in suppression of larval growth. Congenitally athymic nude mice, and mice treated to remove thymocytes had high susceptibility to infection, while mice strains assessed as having high helper T lymphocyte function showed resistance to infection. The degree of antibody response shown by the host does not correlate with the susceptibility to E. multilocularis. Infection with E. multilocularis is accompanied by immunosuppression, manifested by inhibition of effector cell chemotaxis and receptor expression, suppressor macrophage and lymphocyte activity, decline in helper T-lymphocyte activity and immune-complex deposition.

Animals↗
PubMed1992

[Effect of mebendazole on glucose uptake of Echinococcus granulosus cysts].

Mice infected with secondary cysts of Echinococcus granulosus were treated ig with mebendazole (Meb) 25 mg.kg-1.d-1 for 7-14 d. At 24 h after the last dose the endocysts in the treated mice were removed out for in vitro cultivation and exposed to [U-14C]glucose 11.1 kBq.ml-1 for 2 min, no apparent difference in radioactivity content in the cyst walls between the treated and control groups was observed. When [U-14C]glucose was given iv to the infected mice 24 h after they had been treated ig with Meb 25 mg.kg-1 or 50 mg.kg-1 daily for 14 d, the radioactivity content in the cyst wall and cyst fluid decreased significantly as compared to the corresponding control group. Nevertheless, no apparent change in the incorporation of radioactivity into the endogenous glycogen of the parasites was observed, although the glycogen in the cyst wall decreased markedly.

Animals↗
PubMed1992

Synthesis and in vitro activity of alkylaminoalkyloxy chromones on protoscoleces of Echinococcus multilocularis (Cestoda).

Twelve derivatives with alkylaminoalkyloxy chromone structures were synthesized and tested upon protoscoleces of Echinococcus multilocularis metacestode kept alive in vitro. Assays were performed with protoscoleces attached to the germinal layer in open and in closed vesicles. Compounds IVb and IIIe at the concentration of 0.1 mmol.L-1 killed 50% of the protoscoleces in open vesicles in 48 hours and compound IVb killed 100% of the protoscoleces in open vesicles within 96 hours at the same concentration. In closed vesicles after four days compound IVb killed all protoscoleces, compounds IIIe and IVd half of them, whereas in the controls all protoscoleces were alive. Trifluoperazine (TFP) was the reference compound; none of the new compounds showed better activity than TFP.

Animals↗
PubMed1992

Effects of mebendazole, albendazole, and praziquantel on alkaline phosphatase, acid phosphatase, and adenosine triphosphatase of Echinococcus granulosus cysts harbored in mice.

Mice infected with protoscoleces of Echinococcus granulosus for 12-14 months were treated ig with mebendazole (Meb) 25-50 mg.kg-1 x d-1 for 7-14 d, albendazole (Alb) 200 mg.kg-1 x d-1, cr praziquantel (Pra) 500 mg.kg-1 x d-1 for 14 d. The mice were killed 24 h after the last medication, and acid phosphatase (ACP), alkaline phosphatase (AKP), and adenosine triphosphatase (ATPase) including (Na, K, Mg)-ATPase, (Na, K)-ATPase, and (Mg)-ATPase were determined and compared with those of untreated control group. The results showed that ACP activities of cyst wall in treated groups were lower than the control group. Whereas AKP activity of cyst wall in Pra group increased markedly, this is not the case in Meb and Alb groups. Three ATPase activities of cyst wall were inhibited in both Meb and Alb groups, Meb being more potent. No apparent changes in the ATPase activities were seen in Pra group.

Acid Phosphatase↗
PubMed1992

[Observation on ultrastructure of sterile cysts of Echinococcus granulosus in mice].

The fine structure of sterile cysts of Echinococcus granulosus in mice was studied by TEM. The cyst wall consists of laminated layer and germinal membrane. At ultrastructural level, the laminated layer contains microfibrillate matrix and irregularly shaped electron-dense granules. The germinal membrane comprise of tegument and cell region. Plasmalemma invagination resembling the "pinocytotic vesicle" are seen between the microtriches of the tegument, and mitochondria are seen in the basal portion of the tegument. In the cell region, there are tegumental cells, muscle cells, and glycogen-containing cells. "Nucleolar channel system" can be observed in some of the glycogen-containing cells.

Animals↗