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PubMed2003

Echinococcus multilocularis (Cestoda, Taeniidae) in Red foxes (Vulpes vulpes) in northern Belgium.

The first record of the tapeworm Echinococcus multilocularis (Cestoda, Taeniidae) in Red foxes (Vulpes vulpes) in northern Belgium is described. Between 1996 and 1999, 237 dead foxes were examined for the presence of this tapeworm using the intestinal scraping technique. Four foxes (1.7%) were found to be infected with E. multilocularis and showed medium to very high parasitic burdens. Three infected foxes originated from the south of the study area and the fourth animal came from the north of the study area near the border with The Netherlands. These findings are discussed in relation to the high endemicity of E. multilocularis in southern Belgium and to the increased distribution of the Red fox (V. vulpes) in northern Belgium during the last two decades.

Animals↗
PubMed1999

Taenia solium cysticercosis: immunity in pigs induced by primary infection.

The present study demonstrates that pigs experimentally infected with Taenia solium eggs develop resistance to reinfection that lasts at least five months. Thirteen 2-month-old piglets were infected with eggs of Taenia solium. After 5 months, two pigs were euthanized and five were challenged with eggs from a second tapeworm. Nine months after the first infection, six pigs were challenged with a third tapeworm. All 11 challenged pigs were euthanized 2 months after reinfection. In order to confirm the infectivity of the eggs, several piglets were inoculated with each taenia. Two of the five pigs reinfected after 5 months did not develop metacestodes, two showed few caseous non-infective forms and in the fifth pig, 14% of the metacestodes were vesicular and 86% colloidal and caseous. In the six animals challenged 9 months after the first infection, three were heavily infected with vesicular metacestodes and the other three showed only colloid and caseous forms in muscles. All parasites found in brains were vesicular. We conclude that immunity due to primary infection lasts at least 5 months. At 2 months of infection antigens of 24 and 39-42 kDa were the most frequently recognised. In those pigs with only a few caseous cysts in muscles and/or vesicular ones in brains no antibodies were detected.

Animals↗
PubMed2001

Anthelmintic screening of Zimbabwean plants traditionally used against schistosomiasis.

Extracts of 23 plant species used popularly against schistosomiasis in Zimbabwe were screened for their anthelmintic effect. Schistosomules of the trematode Schistosoma mansoni and cysticercoids of the cestode Hymenolepis diminuta were studied in vitro. The material consisted of 58 plant extracts, of which 37 killed the newly excysted cysticercoids within an hour, when incubated in a culture medium. Lethal concentrations varied from 0.8 to 103 mg/ml. All plant extracts showed activity against the tapeworms after 24 h. Ten of the best extracts were also tested against schistosomules. Five of these extracts showed activity. Lethal concentrations varied from 0.6 to 33.8 mg/ml of dry plant material. Extracts of stem and root from Abrus precatorius (Fabaceae), of root bark and leaves from Ozoroa insignis (Anacardiaceae) and of root bark from Zizyphus mucronata (Rhamnaceae) gave the best results against tapeworms. The best results against schistosomules were obtained with stem and root extracts from Abrus precatorius (Fabaceae) and stem bark from Elephantorrhiza goetzei (Mimosaceae). Although the activity of root and root bark extracts commonly used in traditional medicine was verified in this study, our results showed that also extracts from leaf and stem can be effective anthelmintics.

Animals↗
PubMed2004

Immunization of rodents against Hymenolepis infections using non-viable homologous oncospheres.

Immunity to Taiwan Taenia infection in pigs can be stimulated using homologous or heterologous non-viable Taenia oncospheres. This study was designed to determine whether homologous non-viable oncospheres could stimulate immunity to Hymenolepis infection in rodents. Hatched oncospheres were prepared from eggs of Hymenolepis diminuta, Hymenolepis nana, and Hymenolepis microstoma and kept at -70 degrees C for more than 1 month. A mixture of 500 non-viable oncospheres of each tapeworm and complete Freund's adjuvant was injected subcutaneously in four groups of Sprague-Dawley rats or ICR mice one to four times at an interval of 1 week; controls were not immunized. After immunization, each rodent was orally inoculated with three fresh active cysticercoids of H. diminuta or H. microstoma or 500 fresh eggs of H. nana. The animals were then necropsied for adult tapeworms. No rats or mice immunized with non-viable oncospheres of H. diminuta or H. nana were infected by the challenge inoculation. However, 28 of 34 mice immunized with non-viable H. microstoma oncospheres were infected after inoculation with cysticercoids. This study demonstrated complete protection against infection by homologous parasites in rats or mice immunized with non-viable oncospheres of H. diminuta and H. nana, respectively. Repeated immunization may not be required if resistance is stimulated in rodent hosts.

Animals↗
PubMed1990

The pig as an intermediate host for Taiwan Taenia infection.

Eggs (1000-100,000/animal) of Taiwan Taenia were inoculated per os into 14 Small-Ear-Miniature (SEM), 19 Landrace-Small-Ear-Miniature (L-SEM), and 5 Duroc-Yorkshire-Landrace (DYL) pigs. These animals were sacrificed 7-107 days after infection. Thirty-four pigs were found to be infected with Taiwan Taenia cysticerci and the infection rates of SEM, L-SEM, and DYL were 86%, 89% and 100% respectively. The cysticerci recovery rates of SEM, L-SEM and DYL pigs were 27.2%, 1.7% and 0.27% respectively. Cysticerci were recovered only from the livers and none were found in muscles, viscera or other parts of the carcasses. More cysticerci were located in the liver parenchyma (71%) than on the liver surface (29%). Taiwan Taenia cysticerci were smaller than those of classical T. saginata or T. solium. Moreover, Taiwan Taenia cysticerci had 2 rows of rudimentary hooklets on the scolex. The results of this study indicate that young pigs are good intermediate hosts for Taiwan Taenia and that the SEM pig is a satisfactory host for experimental studies with this tapeworm. These results were similar to other studies with different geographic strains of the T. saginata-like tapeworm in the Far East. These strains appear to be the same and possibly a new species.

Animals↗
PubMed1995

Morphological description of Taenia saginata asiatica (Cyclophyllidea: Taeniidae) from man in Asia.

In order to clarify the taxonomic status of the Taenia saginata-like tapeworm in East Asia, the morphological characteristics of the adult and cysticercus of classical T. saginata (American, Swiss and Poland strains) and the Taiwan Taenia were compared in the present study. The morphologic characteristics of these two parasites are very similar. The protoscolex of cysticercus of the Taiwan Taenia has a sunken rostellum while that of classical T. saginata has only an apical pit. In addition, the rostellum of the Taiwan Taenia cysticercus is usually surrounded by two rows of rudimentary hooklets. However, this structure is rarely found in classical T. saginata. Based on the results of molecular studies and morphological characteristics, the T. saginata-like tapeworm in East Asia represents a subspecies of T. saginata, named T. saginata asiatica.

Animals↗
PubMed1990

Hymenolepis diminuta (Cestoda) liberates an inhibitor of proteolytic enzymes during in vitro incubation.

Hymenolepis diminuta liberated measurable amounts of 'Lowry-positive material' (LPM) and protein during incubation for 2 h in vitro. When tapeworms were incubated in the presence of bovine trypsin (BT), or when BT was added to the medium after removing the tapeworms, the enzyme's proteolytic activity was inhibited significantly. Centrifugation of the medium at 30,000 g yielded a pellet composed of tegumental elements, but this fraction did not inhibit BT. The 30,000 g supernatant fraction contained a chemical(s) that inhibited the proteolytic enzymes of the rodent host's intestinal contents (IC). The inhibitor(s) was stable following repeated freeze-thaw cycles, heat labile, and not degraded by BT or IC, and it inhibited the amidase activity of BT in a non-competitive manner.

Analysis of Variance↗
PubMed2004

An experimental field approach to parasitism and immune defence in voles.

The fox tapeworm Echinococcus multilocularis is typically perpetuated in a cycle with red foxes as definitive hosts and various rodent species as intermediate hosts. In this study, foxes were baited with a highly efficient drug against cestodes (praziquantel) in 5 blocks of 1 km2. Voles, Arvicola terrestris, the most abundant intermediate host species, were trapped in the 5 baited blocks and in 5 non-baited control blocks. Baiting the foxes reduced the prevalence of E. multilocularis in fox faecal samples in the baited blocks, but voles trapped in the two blocks did not differ in their infection rates. However, voles from the baited blocks had significantly smaller spleen masses and were more likely to be infested with mites than those from the control blocks, possibly reflecting different immunological activities. Our study suggests that the environmental contamination with E. multilocularis eggs, and perhaps those of other tapeworms, influences the immune system of the intermediate host species A. terrestris in the wild.

Animals↗
PubMed2005

Phylogeny, evolution and host-parasite relationships of the order Proteocephalidea (Eucestoda) as revealed by combined analysis and secondary structure characters.

In a manner similar to many other groups of organisms, the tapeworm order Proteocephalidea poses a difficult phylogenetic problem if treated on the basis of single-gene analysis. Since the biogeography and host distribution of proteocephalideans make these tapeworms a potentially interesting model for evolutionary and co-evolutionary studies, we tried to resolve their phylogenetic relationships by applying a multi-gene approach. The ITS2 sequences and V4 hypervariable loop of 18S rRNA were obtained for 43 and 35 proteocephalidean taxa, respectively, and combined with other sequences available in the GenBank. The phylogenetic analysis of the combined DNA set was confronted with characters derived from ITS2 secondary structures. Using this approach, a species-rich Neotropical lineage of proteocephalideans could be reliably resolved. The phylogenetic relationships within this group show a high degree of phylogeny-independent host distribution. The reconstruction of ITS2 secondary structure revealed a universal 4-domain arrangement, which is conserved across a wide range of Neodermata. Several motifs of the secondary structure could be mapped to the phylogenetic tree as possible clade synapomorphies.

Animals↗
PubMed1997

Phylogenetic relationships of three hymenolepidid species inferred from nuclear ribosomal and mitochondrial DNA sequences.

Three hymenolepidid tapeworms, Hymenolepis diminuta, H. nana and H. microstoma, are commonly maintained in laboratory rodents and used in many experimental model systems of tapeworm infections. We examined partial sequences from the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene and nuclear ribosomal internal transcribed spacer 2 (ITS2) sequences to infer phylogenetic relationships of the 3 hymenolepidid species. Parts of the CO1 gene and ITS2 were amplified by PCR and sequenced directly. The CO1 gene sequence obtained was the same in length (391 bp) among all specimens. In the case of ITS2, however, several insertions and deletions were detected (671-741 bp) not only among species but also between an American isolate and a Japanese isolate of H. diminuta. Percentage nucleotide differences between H. diminuta and H. microstoma, or H. diminuta and H. nana were 16.6-18.2% for the CO1 gene and 21.3-22.9% for ITS2. The differences in both sequences between H. microstoma and H. nana were about 14%. Phylogenetic trees inferred from both of the nucleotide sequences showed similar topology, and suggest that H. diminuta may have diverged from the common ancestral line the earliest, and that H. nana is closer to H. microstoma than to H. diminuta.

Amino Acid Sequence↗
PubMed2001

Two new species of Litobothrium Dailey, 1969 (Cestoda: Litobothriidea) from thresher sharks in the Gulf of California, Mexico, with redescriptions of two species in the genus.

As part of a survey of the metazoan parasites of elasmobranchs of the Gulf of California, Mexico, the spiral intestines of 10 pelagic thresher sharks Alopias pelagicus and one bigeye thresher shark A. superciliosus were examined for tapeworms. Eight of the A. pelagicus specimens examined were found to host Litobothrium amplifica and L. daileyi. Both tapeworm species are redescribed based on examination of this new material with light and scanning electron microscopy, and the ranges of most of the measurements for these species are expanded; scanning electron micrographs and detailed illustrations and measurements of their segment anatomy are presented for the first time. An argument is made that the identification of the original host specimens of these species was in error and that A. pelagicus is likely to be the correct original host. In addition, L. nickoli n. sp., a third species in the genus hosted by A. pelagicus, was found in three of the 10 individual hosts examined. This species differs from all six known Litobothrium species in the form of the pseudosegments of the scolex, the anterior two being essentially non-cruciform, while the latter three are distinctly cruciform. All other species possess either no non-cruciform or at most one non-cruciform segment anteriorly. The single specimen of A. superciliosus examined was found to host the new species, L. janovyi. This species differs from L. coniformis, L. gracile and L. amsichensis in its possession of four rather than three, three and five cruciform pseudosegments, respectively. It lacks the modificiations of the fourth pseudosegment seen in L. amplifica and lacks the anterior non-cruciform fifth pseudosegment found in L. daileyi. It most closely resembles L. alopias but differs among other features in its greater total length, greater number of segments and longer mature segments. SEM of the four species collected from the Gulf of California as well as material of L. amsichensis from the goblin shark Mitsukurina owstoni that hosted the type-specimens of this species show that all surfaces of the body of all five species bear a dense covering of long filiform microtriches. L. amplifica bears a single row of large spine-like structures throughout most of the posterior margins of the first and second cruciform pseudosegment only. L. daileyi possesses one to two rows of overlapping spine-like structures on the posterior margins of the first four pseudosegments with the exception of the medial projections. The fifth pseudosegment lacks these structures. L. janovyi n. sp. bears spine-like structures on the lateral margins of only the third and fourth pseudosegments. L. nickoli n. sp. bears spine-like structures throughout the posterior margins of the first and second pseudosegments, and throughout the posterior margins of the third and fourth pseudosegments with the exception of the medial projections; the fifth pseudosegment lacks these structures. L. amsichensis bears no structures that could be considered to be spine-like on any of its pseuosegments, but possesses a border of densely arranged larger microtriches on the posterior margin of all five pseudosegments. A key to the species is included.

Animals↗
PubMed2001

Two new species of Acanthobothrium Beneden, 1849 (Tetraphyllidea: Onchobothriidae) from horn sharks in the Gulf of California, Mexico.

Between 1993 and 1996, 26 individuals of two species of horn sharks were collected from the upper Gulf of California and their spiral intestines examined for onchobothriid tapeworms. Heterodontus francisci was found to host Acanthobothrium puertecitense n. sp. Based on the criteria of Ghoshroy & Caira (2001), this is a Category 4 species (with >15 mm total length, >50 proglottids, >80 testes and a symmetrical ovary). It differs from the four Category 4 species previously reported from either the western Atlantic or eastern Pacific Oceans, including A. bajaense (emend.) which was described from H. francisci, in hook-shape, total length, number of proglottids, number of testes and number of columns of vitelline follicles. H. mexicanus was found to host Acanthobothrium santarosaliense n. sp., which, based on the criteria of Ghoshroy & Caira (2001) is a Category 3 species (with >15 mm total length, >50 proglottids, >80 testes and an asymmetrical ovary). A. santarosaliense differs from the five Category 3 species previously reported from either the western Atlantic or eastern Pacific Oceans in its size, euapolytic nature, lack of dark matrix from the bases of the hooks, hook-shape, and distribution and number of testes. In addition to the difference in ovarian symmetry, A. puertecitense possesses fewer testes, fewer proglottids, is a shorter worm, possesses a more anterior genital pore and vitelline follicles which extend further forward anteriorly than in A. santarosaliense. This represents the first report of onchobothriids from H. mexicanus and the first report of onchobothriids from H. francisci in the Gulf of California. The apparent host-specificity of both new species should be viewed with caution until a greater sample of host individuals of both species can be examined. The fact that both new tapeworm species are known only from the Gulf is also considered to be a preliminary result, given the small sample of host individuals examined from these regions to date. This brings the total number of species of Heterodontus known to host Acanthobothrium to four and the total number of Acanthobothrium species described from heterodontiform sharks to five.

Animals↗
PubMed2002

Experimental studies on the lead accumulation in the cestode Hymenolepis diminuta and its final host, Rattus norvegicus.

It recently became clear that acanthocephalans parasitizing mammals can bioconcentrate several heavy metals to conspicuously higher concentrations than the tissues of their definitive hosts. As cestodes are more abundant in terrestrial animals than acanthocephalans, and thus potentially more useful in attempts toward passive as well as active biomonitoring, a very common tapeworm and its synanthropic mammalian host were selected for the present study. The tapeworm Hymenolepis diminuta and experimentally infected male Wistar rats of the CD-M-strain were investigated with respect to their lead accumulation. The worms were allowed to grow up for five weeks post infection followed by a five weeks oral lead exposure of the rats. After the exposure period the rats were killed and the metal levels were determined in muscle, liver, intestine, testes and kidney of the rats as well as in the parasites. Lead concentrations were found to be 17 times higher in the cestodes than in kidney, whereas metal levels in all other host tissues were below the detection limit. Thus, this study reveals that lead accumulation also occurs in cestodes parasitizing mammals. Due to a lack of adequate sentinel species in terrestrial habitats the host-parasite-system rat-H. diminuta appears to be a useful and promising bioindication system especially in urban ecosystems.

Animals↗
PubMed2004

Oribatid mites as intermediate hosts of Anoplocephala manubriata, cestode of the Asian elephant in India.

Anoplocephala manubriata (Cestoda: Anoplocephalidae) is a tapeworm that parasitizes both African (Loxodonta africana) and Asian (Elephas maximas) elephants. Its life cycle has not yet been completely elucidated nor have intermediate hosts been previously reported. Soil and substrate was collected in the Kodanadu Forest Range, Ernakulum District and Guruvayur Devaswom Temple grounds, Thrissur District, in Kerala, India. Oribatid mites (Acari: Oribatida) were collected from dung piles near captive elephants' bedding and examined for immature stages of the tapeworm. Five species of oribatids were found to contain at least one immature life stage of A. manubriata: Galumna flabellifera orientalis Hammer 1958, Scheloribates latipes (C.L. Koch 1844), S. praeincisus (Berlese 1913), Protoribates seminudus (Hammer 1971), and P. triangularis (Hammer 1971).

Animals↗
PubMed1989

Vaccination against ovine cysticercosis using a defined recombinant antigen.

Cysticercosis caused by larval tapeworms is a major public health problem and a cause of substantial economic losses in the farm-animal industries. Taenia ovis in sheep is a particularly important example. Immunity to reinfection with the larvae has a central role in regulating natural transmission of the parasites, and vaccination with antigens from the early larval oncosphere stage can induce complete protection against infection. As it is impractical to obtain enough oncospheres for a commercial vaccine against these tapeworms, an alternative approach is to use recombinant DNA methods to generate a cheap and plentiful supply of antigens. We report here the expression in Escherichia coli of complementary DNA encoding T. ovis antigens as fusion proteins with the Schistosoma japonicum glutathione S-transferase. Vaccination of sheep with these fusion proteins gave significant, although not complete, immunity against challenge infection with T. ovis eggs. Commercial development of a vaccine is being pursued.

Amino Acid Sequence↗
PubMed2002

Chemical structures and immunolocalization of glycosphingolipids isolated from Diphyllobothrium hottai adult worms and plerocercoids.

Glycosphingolipids (GSLs) were purified from adults and plerocercoids of the tapeworm Diphyllobothrium hottai, and their chemical structures were determined. Total lipid fractions prepared from chloroform/methanol extracts of whole tissues were fractionated successively on ion-exchange chromatography, silicic acid column chromatography, and preparative TLC. The purified GSLs were characterized by methylation analysis, TLC-immunostaining, liquid secondary ion MS, MALDI-TOF MS, and 1H-NMR. Ten GSLs were isolated from adult worms and four from plerocercoids, comprising mono-, di-, tri-, tetra-, and pentasaccharides. The GSL Gal beta 1-4(Fuc alpha 1-3)Glc beta 1-3Gal beta 1-Cer was found in adult worms but not in plerocercoids, whereas Ga lbeta 1-4 (Fuc alpha 1-3)Glc beta 1-3(Gal beta 1-6)Gal beta 1-Cer was found in both adult worms and plerocercoids. We previously found a similar series of GSLs in plerocercoids of the cestode Spirometra erinaceieuropaei, and termed them 'spirometosides'[Kawakami, Y. et al. (1996) Eur J. Biochem. 239, 905-911]. The core structure of spirometosides, Gal beta 1-4Glc beta 1-3 Gal beta 1-Cer, may have taxonomic significance, being characteristic of pseudophyllidean tapeworms. In the present study, GSL compositions were significantly different between adults and plerocercoids, and growth-dependent changes in composition were documented. We found a novel dihexosylceramide, Glc beta 1-3Gal beta 1-Cer, which is a possible precursor for spirometosides. Immunohistochemical examination showed that spirometoside GSLs are highly enriched in the inner surface of bothria, the major point of contact between the adult worm and the host's intestine. Our findings indicate that spirometosides are involved in host-parasite interaction.

Animals↗
PubMed1992

[Taenia crassiceps in the anterior chamber of the human eye. A case report].

An otherwise healthy 15-year-old girl developed an iridocyclitis in her right eye. A contractable living parasite measuring two millimeter could be detected in the anterior chamber, the other parts of the eye remained uninvolved. The patient had close contact with the young dog of the family. By using a viscoelastic substance the parasite could be removed alive without any complications. The tapeworm was found to be too young for having developed the characteristic scolex. Western-immunoblotting gave indirect evidence for infection with Taenia crassiceps, a dog's tapeworm. During an observation period of two years no evidence for any other ocular or general Taenia crassiceps infestations could be found.

Adolescent↗
PubMed1987

[Subretinal cysticercosis].

This paper communicates the history of a case of subretinal cysticercosis in the left eye of a 73-year-old female patient. The only subjective complaints were slightly blurred vision in the affected eye. Serological findings in the blood (Agar-Gel precipitation; IFAT; ELISA) and the aqueous humor were negative. However, according to the literature false-negative serological findings are not uncommon. A stool examination for worm eggs or tapeworm segments was also negative. The remaining lab findings, including hemogram and immunoelectrophoresis, were also normal. Neurocysticercosis was ruled out by clinical and roentgenologic (CCT) diagnosis. As the patient declined treatment with praziquantel, a modern treatment for tapeworm, photocoagulation of the cysticercus was performed at two sittings, first peripheral demarcation and subsequently central coagulation.

Aged↗