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[Isoelectric focusing analysis of Echinococcus multilocularis protoscolex antigens].

OBJECTIVE: To understand the components of the crude antigens of Echinococcus multilocularis protoscoleces. METHODS: Isoelectric focusing was carried out to fractionate the protein components of E. multilocularis protoscoleces. The individual fractions were collected and subjected to SDS-PAGE, the gels were analyzed by a gel analysis system. RESULTS: The pI values of individual fractions varied from 4.0 to 8.5, while the molecule weights of main protein bands were 72/73, 62/63, 42/44, 35/36, 34 and 21/22 kDa. CONCLUSION: An alternative separation method of crude antigens of Echinococcus multilocularis was established.

Animals↗

[Experimental observation on anaphylaxis induced by Echinococcus infection in Meriones unguiculatus].

OBJECTIVE: To observe the anaphylaxis induced by Echinococcus granulosus or E. multilocularis (E. g. and E. m.) infection in Meriones unguiculatus. METHODS: 56 and 48 gerbils were intraperitoneally inoculated with E. g. protoscoleces and E. m. tissue homogenate. After three months, the anaphylactic responses initiated by intraperitoneal challenge injection with E. g. cystic fluids or partially purified antigen or E. m. metacestode homogenate antigen were observed. IgE antibody and direct eosinophilic leukocyte count (DELC) were detected at pre-postchallenge. RESULTS: The infection rates for E. g and E. m. in 56 and 48 gerbils were 89.3% and 97.9%, respectively. Among these groups, the lowest rate of anaphylaxis was 62.5%, the highest was 100%. The lowest rate of anaphylactic shock was 12.5%, and the highest 16.7%. After the gerbis were infected with E. g. and E. m., both IgE antibody and DELC increased gradually. At 60 min post challenge, IgE antibody level were significantly decreased, while DELC showed a sharp increase. CONCLUSION: Anaphylaxis could be induced in gerbils by Echinococcus infection followed by a challenge injection. Different antigens lead to different and degrees among the anaphylactic responses in the gerbils, however, there were no significant differences between E. g. and E. m. infections in gerbils.

Anaphylaxis↗

Sylvatic echinococcosis in Argentina. II. Susceptibility of wild carnivores to Echinococcus granulosus (Batsch, 1786) and host-induced morphological variation.

Domestic dogs and cats, 3 fox species, Dusicyon culpaeus (Molina,1782), D, griseus (Gray, 1837) and D. gymnocercus (Thomas, 1914), Geoffroy's cats, Felis geoffroyi (D'Orbigny and Gervais, 1843), and grisons, Galictus cuja (Molina, 1782) were fed larvae of Echinococcus granulosus (Batsch, 1786) from domestic sheep in Argentina. Dogs and the 3 species of foxes became infected. The susceptibility of D. culpaeus compared favorably to that of dogs. Most D. griseus and D. gymnocercus were less susceptible than dogs but gravid strobilae were recovered from some animals of both species. Eggs from strobilae in dogs and Dusicyon spp. were infective to CF1 mice. The mean strobilar length and the diameters of the rostellar pad and suckers of worms in foxes were significantly reduced when compared with previously reported data for strobilae from dogs. The potential significance of Dusicyon spp. as reservoir hosts of E. granulosus in Argentina is discussed as is the confusion surrounding the taxonomic identification of cestode infections previously reported from these wild carnivores. It is suggested that Echinococcus spp. reported from Argentine foxes are E. granulosus and that foxes become infected by killing and scavenging on sheep in localities where E. granulosus is endemic.

Animals↗

Short report: Identification of Echinococcus species from a yak in the Qinghai-Tibet plateau region of China.

The species identification of an echinococcal lesion in the liver of a yak in the Qinghai-Tibet plateau region of China, where both Echinococcus granulosus and E. multilocularis are present, was difficult to determine because of the atypical appearance of the lesion. Polymerase chain reaction-based mitochondrial genotyping allowed us to discriminate the Echinococcus species. Nucleotide sequences of the cytochrome c oxidase subunit 1 (cox1) and cytochrome b (cytb) genes amplified from the echinococcal lesion demonstrated that the yak was infected with the E. granulosus G1 genotype (sheep strain).

Animals↗

[The ecology of Echinococcus multilocularis (Leuckart, 1863) and E. granulosus (Batsch, 1786) on the Kamchatka Peninsula].

Some aspects of dwelling of Echinococcus multilocularis and E. granulosus populations in the Kamchatka Peninsula were considered. Transformation of their natural foci to natural synanthropic due to enrichment of mammalian fauna, increased human density and rural development was noticed. Main quantitative characteristics of infectivity of the worm definitive and intermediate hosts are presented using literature and the author's own data. A correlation was noted between host density and their infectivity with Echinococcus.

Animal Diseases↗

[Western blotting analysis of specific antigens from different components of Echinococcus metacestodes].

OBJECTIVE: To analyze antigens for searching specific antigenic components for immunodiagnosis of echinococcosis. METHODS: Fourteen crude antigens from different tissues (cyst fluid, protoscoleces, laminated layer and germinal layer) of Echinococcus granulosus and E. multilocularis metacestodes and other 4 species of cestodes were analyzed by Western blotting. The differences of protein bands were compared for the 14 crude antigens by reacting with pooled sera from cystic echinococcosis (CE) and alveolar echinococcosis (AE) patients. RESULTS: Eleven protein bands from the antigens reacted nonspecifically with sera from both CE and AE patients were Mr 130000, 100000, 94000, 80000, 75000, 66000, 62000, 52000, 38000, 32000, 24000. The highly specific protein bands recognized by AE sera were Mr 120000, 109000, 86000, 59000, 43000, 28000, 20000, 18000, and by CE sera were Mr 41000, 40000, 22000, 16000 and 12000. CONCLUSION: Different antigens shared by the two species of Echinococcus were examined and potential antigenic proteins specific for AE or CE sera were found, providing useful information for further identifying specific antigens for immunodiagnosis.

Animals↗

Short report: the use of a polymerase chain reaction to detect Echinococcus granulosus (G1 strain) eggs in soil samples.

Cystic echinococcosis is a re-emerging disease in central Asia. A total of 120 soil samples taken from 30 gardens of rural homesteads in southern Kazakhstan were analyzed for the presence of taeniid eggs using a concentration technique. Of these, 21 (17.5%) were shown to be contaminated with taeniid eggs. These isolated taeniid eggs were further analyzed using a polymerase chain reaction specific for the G1 (sheep) strain of the tapeworm Echinococcus granulosus, and five samples were shown to be positive. This study demonstrates the widespread contamination of the environment with E. granulosus eggs in an Echinococcus-endemic area and thus the potential for indirect transmission of E. granulosus to humans from such sources.

Animals↗

[Change of cytokines in mice with Echinococcus multilocularis infection].

OBJECTIVE: To observe the change of six cytokines in mice infected with Echinococcus multilocularis as part of the study on immunological mechanism in the infection. METHODS: Mice were infected by abdominal inoculation of echinococcus protoscoleces. The change of serum level of the cytokines IL-2, IFN-gamma, TNF-alpha, IL-4, IL-5 and IL-10 was determined by ELISA during the infection which lasted for 260 d. RESULTS: Compared with uninfected control, the levels of the cytokines all significantly increased in the 260 d. The level of IL-2 reached a peak after 80 d post-infection (p.i.), then decreased quickly after 140 d p.i., High level of TNF-alpha was detected after 40 d, compared to uninfected control, reached a peak at 100 d p.i., and decreased quickly after 140 d. The level of IFN-gamma reached a peak after 80 d p.i., and decreased slowly after 140 d p.i. The levels of IL-4, IL-5 and IL-10 remained lower before 80 d, and increased sharply after 100 days. The levels of IL-4 and IL-10 reached peaks at 100 d p.i., and that of IL-5 at 140 d p.i. CONCLUSION: The data suggest that the induction of Th2 antibody-mediated immunity (AMI) with a parallel expansion of Th1 cell-mediated inflammatory (CMI) responses are important mechanism of the host in defending against the metacestodes. Th1 CMI plays an important role at the early stage of infection, and Th2 AMI is important in the later stage of infection.

Animals↗

[Echinococcus granulosus infection (hydatid cyst): a case report].

Larval Echinococcus granulosus infection (hydatid cyst) was reported in a 10 years-old Ukranian girl. The clinical manifestations were slight since she only complained of frequent abdominal pain. The diagnosis was made by ultrasound and immunoenzymatic detection of antibodies to Echinococcus (ELISA). Antibody titers were 1/800. She was repeatedly treated with albendazol, and she managed to recover while the size of her cyst was reduced.

Animals↗

Histological preparation of the Echinococcus sp. tapeworms: staining affinity of the adult form.

Thirty specimens of Echinococcus sp. obtained by anti-helminthic treatment using arecoline hydrobromide from a dog from an Echinococcosis endemic region were fixed in 10% formalin. The material was processed histologically by a rapid manual method and stained using eleven different techniques. Green Trichrome staining as modified in the present study permitted the observation of large structures of Echinococcus sp. tapeworms.

Animals↗

[Construction of Echinococcus granulosus genomic library].

Using EMBL3 phage DNA as a vector, a perfect genomic library of Echinococcus granulosus from sheep from Xinjiang has been constructed, which contains 1.2 x 10(6) independent recombinants. The main procedure of construction comprised: 1. extraction of Echinococcus granulosus genomic DNA, 2. partial digestion of the extracted E. granulosus genomic DNA with restriction enzyme Sau3Al, 3. harvest of 15-23 kb DNA fragments by electric elution equipment, 4. preparation of EMBL3 phage vector DNA, 5. cleavage of EMBL3 vector DNA with two restriction enzymes Bam HI and Eco RI to remove the central fragment, 6. ligation of the harvested 15-23 kb E. granulosus genomic DNA and the cleavaged vector DNA with T4 DNA ligase, 7. the package reaction of ligated recombinant DNA in vitro with the package protein and with Q359 strain (Spi-) to screen recombinants, 8. identification of the genomic library, 9. hybridization in situ by pSM889 probe, obtaining 6 positive recombinant clones. It was estimated that the E. granulosus genome was about 1.5 x 10(8) bp. A perfect E.g. genomic library is expected to contain 4.6 x 10(4) independent recombinants at minimum. The constructed genomic library has enough independent recombinants (1.2 x 10(6)). This is the first time to establish an E. granulosus genomic library in China. Previous work showed that there existed differences in many aspects, including pathogenicity, among various isolates of E. granulosus from different hosts and areas. We plan to employ this library to screen the E. granulosus intraspecies DNA probe by hybridization in situ. This kind of probe is envisaged to be of advantage for epidemiological investigation of the hydatid disease in China. It also provides a base for researching E. granulosus at the molecular level.

Animals↗

[The ultrastructure of sterile larvocysts of Echinococcus granulosus from different hosts].

The sterile larvocysts of Echinococcus granulosus are characterized by host-dependent morphological variability. The distinctions reside in the intensity of germinative layer development, glycogen and lipid content, ultrastructure of the tegument distal cytoplasm. The larvocysts obtained from one host species in different geographic zones of the country are morphologically similar. The sterile Echinococcus granulosus larvocysts obtained upon experimental infection of mice demonstrate typical morphological signs of the strain used for infection.

Animals↗

Uniform strobilar development of Echinococcus multilocularis in vitro from protoscolex to immature stages.

The aim of this study was to obtain uniformity in strobilar development of Echinococcus multilocularis from protoscoleces in vitro. The isolate of E. multilocularis used was derived initially from a human case in France and subsequently maintained in the laboratory by intraperitoneal passage in Meriones unguiculatus. Protoscoleces used for culture were obtained using preparative procedures in which parasite tissue was disrupted gently with minimal exposure to pepsin and acidic conditions followed by immediate exposure to pancreatin in alkaline solution. Resultant cultures contained large numbers of evaginated, active, vermiform stages, which exhibited uniform strobilar development with formation of the first proglottid and segment and limited maturation of the first proglottid. All worms that exhibited proglottization subsequently segmented. Further proglottization did not occur and all worms degenerated within a few days following segmentation. The results are discussed in light of current knowledge of the relationships of somatic and germinal processes in Echinococcus. In view of these results, further studies should be encouraged to improve strobilar development of E. multilocularis in vitro.

Animals↗

[Effect of d-hydrastine on the ultrastructure of experimental Echinococcus granulosus cyst in mice].

The ultrastructural changes in the germinal membranes of Echinococcus granulosus cysts treated with d-hydrastine (3.75 mg/(kg.d), ig) for 20 d were studied. Cysts from d-hydrastine treated mice were shown by transmission electron microscope to have dissolution of the microtriches, disturbance of organelles in their arrangement, dilatation and disruption of microtubules, increase in size and number of lysosomes, a decrease in number of Golgi complexes and lessening in density and swelling of mitochondria. Under scanning electron microscope, many pits arising from the outer and inner surfaces of the germinal membrane were observed. It seems that d-hydrastine has a profound intracellular effect on experimental Echinococcus granulosus cysts in mice, and that it may be a promising drug for treating hydatidosis.

Alkaloids↗

Echinococcus vogeli Rausch and Bernstein, 1972, from the paca, Cuniculus paca L. (Rodentia: Dasyproctidae), in the Departamento de Santa Cruz, Bolivia.

Among approximately 2,000 mammals examined for helminths in various regions of Bolivia during 1983-1987, cysts of Echinococcus vogeli Rausch and Bernstein, 1972, were found in a single paca, Cuniculus paca L., collected at La Laguna, Departamento de Santa Cruz (lat. 16 degrees 36'W; long. 62 degrees 42'S). This record, the first from Bolivia, represents a considerable extension of the known geographic range of this species in South America. Upon analysis of the morphologic characteristics of the protoscoleces derived from the cysts, the sizes of rostellar hooks from the material from the paca were found to be well within the ranges reported in previous studies. Statistical analysis of frequency distributions of hook characteristics revealed some deviations from normality. These results indicate that parametric statistics should be applied with caution in analyses of inter-and intraspecific variation of morphologic characteristics of hooks of metacestodes of the genus Echinococcus.

Animals↗

Studies on sylvatic echinococcosis. V. Factors influencing prevalence of Echinococcus multilocularis Leuckart 1863, in red foxes from North Dakota, 1965--1972.

A total of 1,153 red foxes, Vulpes vulpes, was examined for strobilae of Echinococcus multilocularis from 2 geographic regions in North Dakota during 1965 through 1972. Echinococcus multilocularis was found in 184 (16%) of these foxes. The data including date and location of collection, age and sex of the host, and presence or absence of the cestode were used to assess the relative influence of collection interval (sampling period), climatic season, geographic location, and age and sex of the host on the prevalence of the adult cestode. The rate of infection varied significantly with collection interval, which was probably attributable to annual changes in the overall environment. Seasonally, the highest prevalences were observed during summer (32.4%) followed by spring (25.3%), autumn (13.7%) and winter (6.4%). Differences in prevalence between adult and juvenile foxes and that between male and female foxes were not significant. A 3-factor analysis of variance showed the order of importance of the significant variables to be collection interval, season, and the interaction of collection interval and season. A 4-factor ANOVA, which in addition to the above variables included geographic location, showed that the collection interval-location interaction had significant effects on prevalence. Also, evidence is presented that suggests that density of the definitive host may in part be responsible for annual fluctuation in prevalence.

Age Factors↗

Hydatid disease in the Turkana District of Kenya. III. The significance of wild animals in the transmission of Echinococcus granulosus, with particular reference to Turkana and Masailand in Kenya.

The results are given of a study on the role of wildlife in the transmission of Echinococcus granulosus in the Turkana and Narok Districts of Kenya. A total of 76 wild carnivores belonging to three separate species was examined from Turkana District. Echinococcus adults were found in 11 of 38 silver-backed jackals (Canis mesomelas) and in six of 22 golden jackals (Canis aureus). This is the first record of golden jackals being infected with this parasite in Kenya. None of 16 spotted hyaenas (Crocuta crocuta) harboured the parasite. Morphological features of the parasites obtained from the jackals were compared with material obtained from dogs in the same area. No morphological differences were recorded when this material was compared with data reported by others, hence the Turkana material belonged to the single species E. granulosus. Three silver-backed jackals and three puppies (Canis familiaris) were successfully infected with protoscolices obtained from a hydatid cyst surgically removed from a Turkana patient. Three spotted hyaenas fed the same material failed to become infected. None of 152 wild herbivores of five species examined in Turkana harboured hydatid cysts. The natural jackal infections in this District are thought to be incidental and dependent on the continuance of the domestic cycle. The role of the Turkana themselves in the perpetuation of the cycle is discussed. Twenty-six wild herbivores of six species were examined for hydatid cysts, in Narok District; hydatids were found in three wildebeest (Connochaetes taurinus) and a single topi (Damaliscus korrigum). The discovery of fertile cysts in wildebeest and the reported infections in lions (Panthera leo), Cape hunting dogs (Lycaon pictus) and silver-backed jackals, support previous evidence of the existence of a wildlife cycle in the Masailand and Serengeti regions of East Africa. The relationship of this cycle to the domestic cycle operating in the same area is unclear and requires further investigation.

Animals↗

[Serological cross-reactions between Echinococcus multilocularis and Dipetalonema viteae infected rodents (author's transl)].

Sera from 30 E. multilocularis infected NMRI-mice and 30 D. viteae infected golden hamsters were tested in the indirect fluorescent antibody (IFAT) and indirect hemagglutination (IHA) tests. In the IFAT there were cross-reactions with all sera, but there were differences between the average titres. While filarial antisera gave higher titres in the homologous system (1:640 against 1:80), it was the opposite with Echinococcus antisera (1:160 against 1:640). Other differences referred to the parasite structures which fluoresced: using Echinococcus antigen the homologous sera gave a bright fluorescence of the outer protoscolex layers including the hooks, while Dipetalonema antisera showed fluorescence of the protoscolex parenchyma only. Thus it is easy to distinguish between homologous and heterologous reactions. Corresponding differences could not be found when using Dipetalonema antigen. In the IHA tests with E. granulosus antigen, which showed an average titre of 1:640 witch E. multilocularis sera, there were few cross-reactions, only 4 out of 30 Dipetalonema antisera giving a positive result.

Animals↗