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PubMed1977

Comparative antigenic characterisation of Echinococcus granulosus and Taenia hydatigena cyst fluids by immunoelectrophoresis.

Hydatid cyst fluid from Echinococcus granulosus (HCF) and cyst fluid from Taenia hydatigena (TCF) cysts were compared in reciprocal immunoelectrophoresis (IEP) tests using homologous and heterologous antisera which were free of antibodies to host serum contaminants. The antigens for the E granulosus arc 5 were demonstrated in TCF. Antibody activity to these and other antigens common to HCF and TCF was removed from homologous antisera by absorptions with the heterologous antigenic preparation. Antigens not shared by the two metacestodes fluids were then demonstrated by IEP tests. These findings are discussed in terms of their significance to phylogenetic and immunodiagnostic studies of these parasites in their immediate hosts.

Animals↗
PubMed1981

Resistance to Echinococcus granulosus infection in lambs.

A high level of resistance of oral infection with Echinococcus granulosus eggs was stimulated in lambs by two or more subcutaneous injections of oncospheres given 14 days apart. The degree of resistance was significantly higher than that resulting from a single injection. Resistance was apparently stimulated by the activated oncosphere or a stage of cyst development prior to 14 days of age. Studies on oncospheres cultured in vitro in sera collected from animals during immunization or after oral challenge showed that most cysts were killed before 7 days of culture had elapsed. This confirmed the observation that resistance was stimulated by an early stage of cyst development. The in vitro test also showed that two injections of oncospheres resulted in a marked increase in the lethal effects of serum. These lethal effects decreased with time, providing circumstantial evidence that the high degree of resistance stimulated by two or more injections may only be transient.

Animals↗
PubMed1981

Comparison of suitability of dogs and cats as hosts of Echinococcus multilocularis.

The suitability of dogs and cats as hosts of Echinococcus multilocularis was studied in animals which had each been infected orally with approximately 15,000 protoscolices. Twenty-one days after injection, the mean number of immature worms recovered from 12 dogs was 874.7 and from 12 cats was 101.7. The mean length of the worms was 1.21 mm in dogs and 1.00 mm in cats. The number and length of worms recovered from dogs were significantly greater (alpha = 0.01).

Animals↗
PubMed1994

[The Echinococcus and complicated forms of hepatic echinococcosis--their surgical treatment].

A series of 137 patients presenting Echinococcus of which 132 (96.3 per cent) with hepatic location, operated in the clinic of hepatobiliary and pancreatic surgery over the period 1984 to 1994, are analyzed. Right-side location is documented in 59.1 per cent, left-side--in 26.5 per cent, and bilateral--in 14.4 per cent of the patients operated on. In 18.2 per cent it is a matter of a multiple process, and in 27.3 per cent--complicated course. Conservative operative procedures are used in 56.1 per cent, mixed--in 18.9 per cent, and radical--in 25 per cent. Overall mortality in the series amounts to 3.03 per cent; in patients subjected to radical operation--0 per cent, and in cases with serious postoperative complications requiring relaparotomy--similarly 3.03 per cent. Biliary fistulas as postoperative complications are noted in 4.5 per cent, and recurrences in the late postoperative period--in 1.5 per cent. The clinical relevance of the diagnostic methods used, and the indications for performing various operative procedures are discussed. The early and long-term postoperative results are assayed against the background of current literature reports on the issue.

Adolescent↗
PubMed1995

Effects of mebendazole, albendazole and praziquantel on alanine aminotransferase and aspartate aminotransferase of Echinococcus granulosus cyst wall harbored in mice.

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of Echinococcus granulosus cyst wall harbored in mice for 10-12 months was measured. The activities of the 2 enzymes were 3,430 +/- 1,370-4,160 +/- 1,790 and 1,560 +/- 840-2,890 +/- 1,470, respectively. When infected mice were treated ig with mebendazole (Meb) 25 mg.kg-1.d-1 for 7-14 d, or 50 mg.kg-1.d-1 for 7 d, the ALT activities of cyst walls of both collapsed and full cysts were inhibited significantly with average inhibition rates of about 50%. Another benzimidazole derivative, albendazole (Alb), also inhibited ALT activity of the cyst wall with an inhibition rate of 40.7%, but this was not the case in the treatment with praziquantel 500 mg.kg-1.d-1 of the infected mice for 14 d. When the infected mice were treated ig with the above mentioned drugs at the same regimens, no apparent effect on AST activities of the cyst wall was seen except for the group treated ig with Meb at a higher daily dose, the inhibition rates being 26% (collapsed cyst) and 43.9% (full cyst). The significance of the results has been discussed briefly.

Alanine Transaminase↗
PubMed1995

The first report of echinococcus multilocularis in domestic dogs in Zhang County of Gansu Province.

In Zhang County of Gansu Province, 13 human cases of alveolar hydatid disease were reported up to 1990. However, the causative organism has not yet been described in animal hosts. In July 1990, postmortem examinations were made on 59 dogs (Canis familiaris) from the Caotan region of Zhang County. Of them, 6 were found to be infected with the adult worms of Echinococcus multilocularis. The morphological characteristics of the adult were compared in detail with those reported from different parts of China. Our adult specimens were closely resembling those of E. multilocularis reported from Ningxia. The role of domestic dogs in the epidemiology of alveolar echinococcosis in Zhang County was discussed.

Animals↗
PubMed1995

Effects of mebendazole, albendazole, and praziquantel on glutathione S-transferase and superoxide dismutase of Echinococcus granulosus cyst wall harbored in mice.

AIM: To explore the existence of glutathione S-transferase (GST) and superoxide dismutase (SOD) in Echinococcus granulosus cyst, and the effect of anthydatid drugs on these 2 enzymes, mice infected with E granulosus protoscoleces for 10-12 months were used. METHODS: The activity of GST was measured by conjugation rate of 1-chloro-2,4-dinitrobenzene with glutathione (reduced form), while the activity of SOD was measured by a modified autoxidation of 1, 2, 3-trihydroxy-benzene method. RESULTS: Activities of both GST and SOD in the cyst wall were 12.3 +/- 4.3 to 13.5 +/- 4.8 mumol min-1/mg protein and 4.4 +/- 2.9 to 6.1 +/- 1.4 U min-1/mg protein, respectively. When infected mice were treated ig with mebendazole (Meb) 25 mg kg-1 d-1 for 14 d, the GST activity of both collapsed and full cyst walls were inhibited by 30.1% and 26.8%, respectively. Whereas SOD activity of the cyst walls were activated by 105%-163%. Albendazole 300 mg kg-1 d-1 for 14 d and praziquantel 500 mg kg-1 d-1 for 14 d had no apparent effect on both GST and SOD of E granulosus cyst wall. CONCLUSION: The results suggested that the inhibition of GST activity in the cyst wall induced by Meb might damage the defence system of the parasite.

Albendazole↗
PubMed1995

Echinococcus multilocularis (Cestoda), the causative agent of alveolar echinococcosis in humans: first record in Poland.

Echinococcus multilocularis, the causative agent of human alveolar echinococcosis, was found for the first time in Poland in 2 of 20 red foxes (Vulpes vulpes), originating from the area of Gdansk (northern Poland). This finding supports the hypothesis that the endemic area of this parasite in central Europe (Belgium, France, Luxembourg, Switzerland, Liechtenstein, Germany, and Austria) is not an isolated focus as previously anticipated but is connected with the large endemic zone in Russia.

Animals↗
PubMed1995

Idiotypic modulation of the antibody response of mice to Echinococcus granulosus antigens.

In this work we analysed the modulation of the antibody response to Echinococcus granulosus antigens via anti-idiotype (Ab2) administration. In a first set of experiments, we determined the antibody response to hydatid cyst fluid antigen (HCFA) of mice immunized with Ab2. Results showed that Ab2 elicited anti-HCFA antibodies in mice that had never been exposed to HCFA before. Moreover, that response was characterized by booster effect, avidity maturation and an inverse correlation between avidity and Ab2 dose. We infected these mice and measured the titre and avidity of anti-HCFA antibodies during 250 days of infection. Lack of avidity maturation was the most important feature observed, suggesting that the parasite (either protoscolex or cyst) could modulate the antibody response of its host. In a second set of experiments, we investigated the presence of regulatory anti-idiotypes in the Ab2 preparation. In this context we treated neonates with different doses of Ab2, immunized them with HCFA 12 weeks later and determined their anti-HCFA titres. A specific and Ab2 dose-dependent suppression of the response to HCFA was observed, suggesting the existence of regulatory anti-idiotypes in the Ab2 preparation. Although this Ab2 could be involved in the regulation of the anti-HCFA response, other anti-idiotypes could also be involved. Our results show that it may be possible to improve the avidity of the anti-HCFA response via the administration of the anti-idiotype Ab. However, the live parasite could successfully revert this effect by mechanisms not yet characterized.

Animals↗
PubMed1993

[RFLP analysis of DNA from Echinococcus granulosus collected from four provinces/autonomous region in China].

A fragment of the ribosomal RNA gene of Schistosoma mansoni pSM889 and two DNA fragments specific to Echinococcus granulosus pHD5 and pEG18 have been used as DNA probes to assess the extent of genetic variability within E. granulosus. The DNA analysis, including restriction endonuclease digestion and Southern blot hybridization with the probes, did not demonstrate any genetic variation among E. granulosus collected from sheep in Xinjiang, Qinghai, Gansu and Ninxia. Similarly, there was no genetic variation among E. granulosus isolates collected from yak in Qinghai and Gansu provinces. The authors deemed that the yak isolates and the sheep isolates of E. granulosus appear to belong to a same strain.

Animals↗
PubMed1994

Purification and characterization of the alkaline phosphatase from Echinococcus granulosus cyst membranes.

The purification to homogeneity and the characterization of Echinococcus granulosus alkaline phosphatase (AP; EC 3.1.3.1) from hydatid cyst membranes are described. After n-butanol extraction, the parasite enzyme was sequentially purified by affinity chromatography on concanavalin A-sepharose followed by gel filtration. The purified protein (210 kDa) had a tetrameric structure composed of 4 56-kDa subunits. Its isoelectric point (4.8) and its kinetic parameters were determined (Km = 0.24 +/- 0.05 mmol/L; Vm = 173 +/- 21 nmol/min/mg protein for p-nitrophenylphosphate). The parasite enzyme differed from the host liver enzyme in its thermal stability, optimum reaction temperature, optimum pH, and catalytic parameters, but not in its apparent molecular weight. Furthermore, sera from patients infected with E. granulosus recognized the parasite AP on immunoblots, whereas uninfected controls were negative. These results as well as the role of this enzyme in the host-parasite relationship emphasize its potential importance as a diagnostic and prognostic antigen in the monitoring of hydatid infection.

Alkaline Phosphatase↗
PubMed1994

Effects of benzimidazole compounds on mice infected with secondary cysts of Echinococcus granulosus.

The effects of mebendazole (Meb), albendazole (Alb) and albendazole sulfoxide (AlbSO) on metacestodes of Echinococcus granulosus have been studied. The results show that Meb and Alb exhibit less effect on protoscoleces in vitro, but in vivo the protoscolicidal effect of Meb is higher than that of Alb. Both Meb and Alb are efficacious in the treatment of mice infected with secondary cysts of E. granulosus. In terms of the minimal effective dose required, the occurrence of collapsed and shrunk cysts after treatment, the drug-induced damage on the germinal layer and the relationship between the drug content in the cyst wall and the damage of germinal layer, the effect of Meb on metacestodes of E. granulosus is higher than that of Alb. The results also indicated that lower drug absorption rate and thickening of the adventitia during longer disease course are the two major factors affecting the efficacy of Meb and Alb, hence suggesting that increase of Meb absorption may be expected to raise the therapeutic effect of the drug. Finally, Alb is not only metabolized to AlbSo and AlbSP in vivo, but also metabolized by the cysts exposed to Alb in vitro. Experimental chemotherapy showed that AlbSO is the major effective metabolite of Alb, and its curative dose is only one half of the parent compound.

Albendazole↗
PubMed1994

Effects of mebendazole, albendazole, and praziquantel on fumarate hydratase, pyruvate kinase, and phosphoenolpyruvate carboxykinase of Echinococcus granulosus cyst wall harbored in mice.

Echinococcus granulosus cyst wall exhibited activities of fumarate hydratase (FH), pyruvate kinase (PK), and phosphoenolpyruvate carboxykinase (PEPCK) with 911-1433, 151-215, and 54-98U, respectively. The ratio of PK/PEPCK was 2.2-2.7, indicating that glycolysis is the main pathway of carbohydrate metabolism in the cyst wall. When infected mice were treated ig with mebendazole, albendazole or praziquantel at the respective daily dose of 25-50, 300, and 500 mg.kg-1 for 7-14 d, no apparent change of FH activity in the cyst wall was found, while PK and PEPCK activities in the cyst wall were markedly inhibited by mebendazole and albendazole. The inhibition rates of PK and PEPCK activities in mebendazole group were 85-88% and 90-92%, respectively, while in albendazole group were 55.3 and 71.6%, respectively. The results suggest that PK or PEPCK in the cyst wall may the important site attacked by effective anti-hydatid drugs.

Albendazole↗
PubMedDate not supplied

[Experimental chemotherapy of echinococcosis. 13. The effect of mebendazole in combination with a vegetable oil on the larval cysts of Echinococcus multilocularis and the reaction of the infested host to long-term administration of the preparation].

The use of mebendazole as a suspension in vegetable oil enhanced the efficiency of treating experimental Echinococcus granulosus infection in outbred albino rats without increasing the dose of the drug. A sharp reduction in platelet count in the blood of the infected animals treated and untreated suggests that thrombohemorrhagic complications might be in echinococcosis. Thrombopenia in the treated animals appeared to be steady-state. A decrease in a rapid immune response in the mebendazole-treated rats, as compared to the untreated ones, is likely to be a consequence of a significant fall of antigenic immune stimulation due to suppression of the parasite's viability with the drug and to be an indicator of therapeutical efficiency.

Animals↗
PubMed1994

Comparative genetic analysis of Swiss and Spanish isolates of Echinococcus granulosus by southern hybridization and Random Amplified Polymorphic DNA technique.

Swiss and Spanish isolates of Echinococcus granulosus were compared using different molecular biological techniques: Genomic DNAs isolated from parasites originating from various intermediate hosts were subjected to Southern hybridization with different probes, the same source of DNA was used for DNA amplification using the Random Amplified Polymorphic DNA (RAPD) technique. With both methods the various isolates (metacestodes) of E. granulosus exhibited characteristic banding patterns which allowed us to assign them to the following groups of homologous profiles: (a) isolates of horse and donkey origin from Spain and Switzerland; (b) isolates of cattle origin from Switzerland; (c) isolates of sheep, cattle and human origin from Spain; (d) isolates of pig origin from Spain and Switzerland and of goat origin from Spain. By RAPD (Southern hybridization not examined) two isolates of human origin from Switzerland were showing banding patterns distinct from groups (a-d). The results provide further evidence that the morphological and biological differences of several strains of E. granulosus are also detectable on the genetic level using molecular biological techniques.

Animals↗
PubMed1993

Generation of CD8+ suppressor T cells by protoscoleces of Echinococcus multilocularis in vitro.

Addition of protoscoleces (PSC) of Echinococcus multiocularis suppressed proliferative responses in spleen cells stimulated with concanavalin A (Con A) on day 3 of culture. The suppression was not observed in the spleen cell population depleted of CD8+ cells but observed in the population depleted of CD4+ cells, suggesting the involvement of the CD8+ T cells in the apparent suppression. Indeed, flow cytometry analysis revealed that the proportion of CD8+ cells markedly increased in the Con A cultures containing PSC. Furthermore, when spleen cells were co-cultured with PSC alone, marked increase in the proportion of CD8+ cells as well as B220+ cells was observed. Addition of these increasing CD8+ cells suppressed the proliferative responses of fresh spleen cells stimulated with Con A. These findings suggest that the low responsiveness of spleen cells to Con A on day 3 of culture in the presence of PSC is attributable to an active suppressor mechanism including CD8+ T-suppressor cells generated by stimulation with PSC.

Animals↗
PubMed1993

Dose-dependent effects of hydatid fluid toxins from Echinococcus granulosus on mouse peritoneal macrophages.

Hydatid fluid (HF) from hydatid cysts of the cestode Echinococcus granulosus inhibited the phagocytosis of bacteria and yeast cells by host macrophages in vitro. Different assays were used to study the dose-dependent effect of partially purified HF toxins on peritoneal macrophages (PM phi) of the mouse. Trypan blue exclusion, as well as measuring the specific release of lactate dehydrogenase activity and 51Cr release of 51Cr-labelled PM phi, showed that incubation with HF toxins lead to the lysis of the target cells. By measuring the effect of the toxins on the reduction of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide by PM phi, and by experimental labelling using [3H]-uridine, a decrease in metabolic activity was seen. However, at non-lytic concentrations, the PM phi showed a peak of metabolic activity. The observations of the effects on macrophages by parasite-derived toxins may be related to a mechanism by which the parasite survives within an immunized host.

Animals↗
PubMed1994

Echinococcus granulosus (Taeniidae) and autochthonous echinococcosis in a North American horse.

We report the first documented case of autochthonous echinococcosis in a horse of North American origin. Three fully mature and viable unilocular hydatid cysts of Echinococcus granulosus (Batsch, 1786) were an incidental finding at necropsy in the liver of a 14-yr-old gelding thoroughbred that had been foaled in Virginia and raised in Maryland. Protoscolices were armed with 2 rows of 28-37 rostellar hooks; small hooks measured 23-30 microns; large hooks measured 26-33 microns. Morphologically, these were compatible with rostellar armature considered typical for the equine strain of E. granulosus currently known primarily from the United Kingdom. This horse had a history of fox hunting, and huntsman at some premises in the region are known to feed uncooked viscera from horse carcasses to their dogs. These factors would support maintenance of infection by E. granulosus in equine hosts. The putative introduction and establishment of the equine strain of E. granulosus and recognition of endemic equine hydatid disease in the eastern U.S.A. warrants monitoring and additional investigation.

Animals↗