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PubMed2006

Prevalence of helminthes in adult dogs in Heilongjiang Province, the People's Republic of China.

The prevalence of helminthes in adult dogs was investigated in Heilongjiang Province, the People's Republic of China, between 1996 and 2004. A total of 178 adult farm dogs from representative geographical locations in Heilongjiang Province were killed and examined for the presence of helminthes using a helminthological approach. The worms were examined, counted, and identified to species according to existing keys and descriptions. A total of 17 species of helminthes were found to infect dogs, and they represented two phyla, three orders, 13 families, and 15 genera. All dogs were infected by more than one helminth species. Clonorchis sinensis (26.4%), Paragonimus westermani (7.9%), and Metagonimus yokogawai (6.2%) were the most common trematode species; Mesocestoides lineatus (20.2%), Taenia hydatigena (19.7%), and Dipylidium caninum (14.6%) were the most common cestodes species; and Ancylostoma caninum (66.3%), Toxocara canis (36.5%), and Trichinella nativa (21.9%) were the most common nematode species. The results of the present investigation provide relevant "base-line" data for assessing the effectiveness of future control strategies against helminth infection in dogs in Heilongjiang Province, China.

Animals↗
PubMed2006

Echinococcus granulosus (Cestoda, Taeniidae) in the Iberian wolf.

The intestinal contents of 27 Iberian wolves (Canis lupus signatus) from Spain were screened for the presence of the taenid cestode Echinococcus granulosus. Four animals were found positive (15% prevalence). The intensity of parasitation was variable (mean 71, range 1-147 E. granulosus per host). Gravid individuals were found in all wolves positive with the parasite. Molecular characterization of the parasite material showed that the wolf strain belongs to the G1 genotype. According to the results, we conclude that the Iberian wolf takes part in the maintenance of the life cycle of this zoonotic parasite in Spain and that this fact could have public health relevance.

Animals↗
PubMed2006

The dynamics of the nematode Anguillicola crassus, Kuvahara 1974 in eel Anguilla anguilla (L. 1758) in the Sebou estuary (Morocco).

The European eel is a vulnerable fish by its complex life cycle, by the impact of pollution of the near total of freshwater aquatic environments, and by the gravity and the diversity of its parasites (nematodes, cestodes, trematodes, the Copepoda, Coccidia...). It is classified in the red book of threatened species. The anguillulose is the principal parasitic pathology of an eel either in the natural environment or in the aquaculture. The eels taken in the three zones of the Sebou estuary of varied environmental conditions were dissected for the research of parasites. Of the fish, 85.7% are infested upstream of the estuary, whereas only 71% shelter this parasite in their swim bladder, with an abundance of 2.09 per fish downstream and 83.8 in zone 2. The present study suggests the development stage of the fish, and therefore its diet, has an influence on the parasitic infestation. The estuaries and the lagoons constitute a very significant medium for the safeguarding and the disinfection of parasitized eels.

Anguilla↗
PubMed2006

Stegodexamene anguillae (Digenea: Lepocreadiidae), an intestinal parasite of eels (Anguilla spp.) in New Caledonia.

Adult trematodes of the genus Stegodexamene Macfarlane, 1951 were recorded from the intestines of two species of freshwater eels, the Pacific short-finned eel Anguilla obscura Günther and the speckled longfin eel Anguilla reinhardtii Steindachner from the Pouembout and La Foa Rivers, New Caledonia, South Pacific. They were identified as Stegodexamene anguillae Macfarlane, 1951, a species previously reported only from eels in New Zealand. The morphology of adult S. anguillae seems to be practically identical with that of the later described Stegodexamene callista Watson 1984 from eels in Australia. The finding of S. anguillae in A. obscura and A. reinhardtii in New Caledonia represents new geographical and host records. In addition to this trematode, two larval specimens of a cestode of the order Proteocephalidea were found in the intestine of one A. obscura from the Pouembout River. No monogenean was found in eels of New Caledonia.

Anguilla↗
PubMed2001

Helminth parasites of the eurasian badger (Meles meles L.) in Spain: a biogeographic approach.

Eighty-five Eurasian badgers, Meles meles (Linnaeus, 1758), from four mainland biogeographic Spanish areas were analysed for helminths. Seventeen helminth species were found: Brachylaima sp., Euparyphium melis and Euryhelmis squamula (Trematoda), Atriotaenia incisa and Mesocestoides sp. (Cestoda) and Aelurostrongylus pridhami, Angiostrongylus vasorum, Aonchotheca putorii, Crenosoma melesi, Mastophorus muris, Molineus patens, Pearsonema plica, Physaloptera sibirica, Strongyloides sp., Trichinella sp., Uncinaria criniformis and Vigisospirura potekhina hugoti (Nematoda). In the Mediterranean area, Aonchotheca putorii, M. patens, Strongyloides sp., and U. criniformis were more prevalent in the occidental part, whereas Atriotaenia incisa and Mesocestoides sp. cestodes showed higher values on the continental slope. Metastrongyloid species (Aelurostrongylus pridhami, Angiostrongylus vasorum and Crenosoma melesi) were only detected in the occidental Mediterranean area. In contrast, spirurid species (Mastophorus muris and Vigisospirura potekhina hugoti) were almost restricted to the continental Mediterranean area. Helminthological differences between areas may result from the badger diet, abiotic factors and biocenosis present in each biogeographic area.

Animals↗
PubMed1996

Free and bound biotin molecules in helminths: a source of artifacts for avidin biotin-based immunoassays.

The avidin-biotin molecular recognition system is widely used in parasite immunology. However, the presence of biotin and/or biotin-containing molecules (BCMs) in samples may lead to erroneous results. In the work reported herein we investigated the extent to which biotin and BCMs present in helminth extracts may interfere in avidin/biotin-based immunoassays and developed an enzyme-linked immunosorbent assay (ELISA) for quantification of these components. In avidin-based ELISA using antinematode monoclonal antibodies, an extract of the nematode Anisakis simplex showed very high background reactivity due to biotin/BCMs, whereas the background reactivity in an extract of the nematode Trichinella spiralis was negligible. To investigate interspecies differences further, we performed Western-blot analyses (with avidin as the detector) of extracts from seven nematodes (A. simplex, Ascaris suum, Toxocara canis, Hysterothylacium aduncum, T. spiralis, and Trichuris muris) and the cestode Bothriocephalus scorpii. Even within superfamilies there was considerable variation in the banding patterns obtained. The above-mentioned results confirm that biotin and BCMs may be a significant source of interference in ELISA and immunoblotting, two of the techniques most widely used in parasitological immunodiagnosis. A competition ELISA designed to allow accurate quantification of biotin and BCMs in helminth extracts likewise indicated very considerable interspecies variation. Both A. simplex and H. aduncum had very high biotin/BCM contents. Microdialysis of extracts in the presence of dimethylsulfoxide to remove free biotin prior to ELISA indicated that the high biotin/BCM content of the H. aduncum extract (but not the A. simplex extract) was very largely due to free biotin. Taken together, these results indicate that extreme caution should be exercised in the use of avidin/biotin-based immunoassays for the detection of helminth antigens and that in many cases it may be better to use an alternative recognition system.

Animals↗
PubMed1997

Ultrastructure of the spermatozoon of Dipylidium caninum (Cestoda, Cyclophyllidea, Dilepididae), an intestinal parasite of Canis familiaris.

We report for the first time the ultrastructure of the spermatozoon of a Dilepididae cestode. The mature spermatozoa of Dipylidium caninum is filiform and tapered at both ends and lacks mitochondria. The anterior extremity exhibits an apical cone of electron-dense material measuring about 600 nm in length and a single helicoidal crested-like body that is 150 nm thick. This single crested-like body is spiralized at an angle of about 40 degrees to the spermatozoon axis. The axoneme, showing the 9 + "l" pattern of the Platyhelminthes, lacks a periaxonemal sheath. The cortical microtubules constitute a continuous, submembranous, electron-dense material, and they are also twisted at an angle of about 40 degrees to the spermatozoon axis. Moreover, the nucleus is coiled in a helix around the axoneme, which is centrally located throughout its length. We demonstrate for the first time the presence of peripheral microtubules twisted to the spermatozoon axis up to the posterior extremity of the gamete.

Animals↗
PubMed1997

The parasitism of fish from Lake Constance--a comparison of present and earlier data.

Commercial fish (perch, roach, bream, dace, and burbot) were caught below Langenargen in 1988-1990. Their infestation with cestodes and digenean trematodes was studied. The results were compared with earlier data. The infestation of perch with Diplostomum spathaceum and Ichthyocotylurus variegatus noted in 1988-1990 had increased as compared with that observed in 1974-1976. The infestation of perch with Triaenophorus nodulosus seen in 1990 had increased as opposed to that noted in 1988. The infestation of bream with D. spathaceum and of perch and roach with Tylodelphys clavata observed in 1988-1990 had remained the same as that seen in 1974-1976. The infestation of perch with D. spathaceum noted in 1988-1990 had decreased as opposed to that reported for 1974-1976. The infestation of bream, dace, and burbot with T. clavata noted in 1988-1990 had decreased as compared with that observed in 1974-1976. The infestation of perch with T. nodulosus seen in 1988/1989 had decreased as opposed to that noted in 1974-1976. All three cyprinids studied as well as the burbot had been less intensively infested in 1988-1990 than in 1974-1976. Only perch had been more intensively infested in 1988-1990 than in 1974-1976, especially with D. spathaceum and I. variegatus.

Animals↗
PubMed1998

Development and morphological variability of Echinococcus granulosus.

Characteristics are presented of Echinococcus granulosus strobila from dogs experimentally infected with protoscolices from a single cyst isolated from the liver of a domestic pig in a central Slovakian district. Adult cestodes are characterized mainly by 28-32 hooks highly variable in shape and size; 26-51 testes situated mostly throughout the proglottis (1 or 3 rows behind the vitelline gland); a lobate ovary; the shape of the uterus, which in 10% of proglottides is more or less spherical, in 62% is saccular with lateral sacculations of variable size, in 27% is saccular without lateral sacculations and in 1% is more or less tubular or strongly ramified; and an intermediately rapid rate of development lasting until between 40 and 44 days p.i. The present report analyzes the high degree of variability of the clone studied, referring to the knowledge on the characteristics of the pig, sheep, and cattle strains of E. granulosus and E. multilocularis species, with which some taxonomic characters of the clone representatives overlap.

Animals↗
PubMed1998

Metabolism of [3-(13)C]-pyruvate by cysticerci of Taenia crassiceps.

Carbon-13 decoupled 1H spin-echo nuclear magnetic resonance (NMR) spectra, with and without 13C population inversion, of extracts of Taenia crassiceps cysticerci incubated in media containing [3-(13C)]-pyruvate showed 13C enrichment in alanine, lactate, acetate, succinate, and citrate. Labeling in the latter three metabolites provides substantial evidence that the malic enzyme reaction in this cestode also functions in the direction opposite to that in which it is normally portrayed. The direct passage of pyruvate from the cytosol to the mitochondrion is suggested by the greater percentage of 13C detected in acetate relative to succinate.

Acetates↗
PubMed1999

Reappraisal of vesicular types in the syncytial tegument of the Echinococcus granulosus protoscolex.

The structure, abundance, and distribution of tegumentary vesicles was compared among Echinococcus granulosus protoscoleces that had been prepared for electron microscopy using four processing schedules: a conventional method, alternative fixations using uranyl acetate or osmium tetroxide-potassium ferricyanide, and a freeze-substitution method. Four morphologically distinct types of vesicles were found in the somal region. The morphology of the first form, with moderately electron-opaque contents, and the second form, with similar size and shape but containing an electron-opaque core, varied little among the preparation methods. Two additional forms of vesicles, with characteristic intensely electron-opaque contents, were revealed only after freeze-substitution. These elongate vesicles were also found in the scolex tegument where they were most conspicuous, and appeared markedly increased in number after freeze-substitution. Large, spherical vesicles with an electron-lucent core embedded in a dense matrix of fibrillar strands were the dominant vesicle forms in the scolex region after all methods of preparation. Fixation by osmium tetroxide-potassium ferricyanide revealed the presence of spherical vesicles with amorphous electron-opaque contents and a few inclusions. This form of vesicle was also observed after freeze-substitution, but the inclusions in the vesicular lumen were more numerous. The variation in the distribution of vesicle forms among the body regions strongly implies a variety of vesicle functions. In addition, our observations suggest that comparative studies of different fixative methods are necessary to demonstrate the detailed vesicular morphology of the tegument of E. granulosus and other cestodes.

Animals↗
PubMed1999

Tegumental topography of the plerocercoid of Gymnorhynchus gigas (Cestoda : Trypanorhyncha).

The tegumental topography of the plerocercoid of Gymnorhynchus gigas is described for the first time. The surface features were examined by scanning electron microscopy. Eight different types of microthrix pattern were found. Differences in the shape and density of microtriches depend on their location. A unique morphological feature is reported herein, namely, filamentous microtriches that were arranged in clusters with a dome-shaped pattern when the bothridial surface was relaxed but sunk into a crater when the bothridial surface was contracted. In contrast to other trypanorhynchan cestodes, palmate microtriches are not found on the tegument of this plerocercoid. The microtriches on the caudal extension gradually increased in length with growing distance from the blastocyst, which showed short knob-like structures. These structures developed into elongated filiform microtriches on the posterior region of the caudal extension.

Animals↗
PubMed2001

Depolarization of the tegument precedes morphological alterations in Echinococcus granulosus protoscoleces incubated with ivermectin.

The nematocidal activity of ivermectin (IVM) largely arises from its activity as a potent agonist of muscular and neuronal glutamate-gated chloride channels. A cestocidal effect has also been suggested following in vitro treatments, but the molecular basis of this activity is not clear. We studied the effect of IVM on the metacestode stage of the tapeworm Echinococcus granulosus by assessing the viability, ultrastructure, and tegumental membrane potential as a function of drug concentration and incubation time. Concentrations of 0.1 and 1.0 microg/ml of IVM had no effect on any of these three parameters for up to 6 days of treatment. A concentration of 10 microg/ml, however, elicited a sequence of alterations that started with a approximately 20-mV depolarization of the tegumental membrane, and was followed by rostellar disorganization, rigid paralysis and, eventually, loss of viability. It is likely that the IVM-induced depolarization of the tegument acts as the signal that initiates the cascade of degenerative processes that leads to the parasite's death. This would place the tegument as the primary target of action of IVM on cestodes. As an appropriate chemotherapy for the hydatid disease is still lacking, the cestocidal effect of IVM reported here is worth considering.

Animals↗
PubMed2004

Intestinal parasites and bacteria of mountain gorillas (Gorilla beringei beringei) in Bwindi Impenetrable National Park, Uganda.

A survey in 1994 examined intestinal helminths and bacterial flora of mountain gorillas (Gorilla beringei beringei) in Bwindi Impenetrable National Park, Uganda. Parasites and bacteria were identified to genus in the feces of two groups of tourist-habituated and one group of non-tourist-habituated mountain gorillas. Eggs were identified as those of an anoplocephalid cestode, and nematode eggs representative of the genera: Trichuris, Ascaris, Oesophagostomum, Strongyloides, and Trichostrongylus. This is the first report of Ascaris lumbricoides-like eggs in mountain gorillas. Fecal samples (n=76) from all groups contained helminth eggs, with strongyle eggs and anoplocephalid eggs being the most common. Salmonella and Campylobacter were found in both gorilla groups. Regular long-term non-invasive fecal monitoring of the populations of mountain gorillas is essential for the prevention and identification of potential health threats by intestinal parasites and bacteria in this highly endangered subspecies.

Animals↗
PubMed2006

Redescription of Kapsulotaenia sandgroundi (Carter, 1943) (Eucestoda: Proteocephalidea: Acanthotaeniinae), a parasite of Varanus komodoensis (Varanoidea: Varanidae) from Indonesia.

The proteocephalidean cestode Kapsulotaenia sandgroundi (Carter, 1943) (Proteocephalidae: Acanthotaeniinae), the type-species of Kapsulotaenia Freze, 1963, is redescribed on the basis of the type-material from Varanus komodoensis Ouwens on Komodo Island, Indonesia, and material from museum collections. The ovary is larger than described by Freze (1965) and occupies 42-59% and not 33% of the proglottis width as cited by Freze. The presence of a small vaginal sphincter and a seminal receptacle are also new observations in all specimens. The microtriches, cross-sections and eggs are figured for the first time. In addition, the ventral osmoregulatory canals are connected to the ventral surface by narrow secondary ducts; the median part of the cirrus-sac is narrower than the distal and proximal regions. Egg clusters and a supplementary layer in the eggs situated between the oncosphere and the bi-layered embryophore, present in K. sandgroundi, are features also observed in the majority of Australian proteocephalideans. It is concluded that much more attention needs to be paid to the careful observation and description of the morphology of the eggs in the Proteocephalidea, as this may represent a valuable discriminatory character for distinguishing species.

Animals↗
PubMed2006

Orectolobicestus n. g. (Cestoda: Tetraphyllidea), with the description of five new species and the transfer of Phyllobothrium chiloscyllii to the new genus.

ORECTOLOBICESTUS N. G. (CESTODA: Tetraphyllidea) is erected for six cestode species parasitising bamboo sharks (Orectolobiformes: Chiloscyllium). Members of this genus differ from all other phyllobothriid genera in possessing modified maisiform spinitriches on their distal bothridial surfaces. In addition, they are easily recognised in that they share the following unique combination of characters: their vitelline fields are interrupted by the ovary, their necks are scutellate, and their bothridia bear an apical sucker and marginal loculi. Five new species of Orectolobicestus are described, including O. tyleri n. sp. from Chiloscyllium punctatum off Borneo, O. lorettae n. sp. from C. cf. punctatum off Australia, O. mukahensis n. sp. and O. kelleyae n. sp. from C. indicum off Borneo, and O. randyi n.sp. from C. hasselti also from off Borneo. In addition, Phyllobothrium chiloscyllii Subhapradha, 1955 is transferred to the new genus. O. chiloscyllii (Subhapradha, 1955) n. comb. is readily distinguished from all five new species in its greater total length. In addition to a number of proglottid features, O. kelleyae n. sp. and O. randyi n. sp. clearly differ from the other three new species in their possession of trifid, rather than fully serrate, spinitriches on their proximal bothridial surfaces. The latter two species conspicuously differ from one another in total number of proglottids (11-21 vs 27-38). O. tyleri n. sp. generally has fewer proglottids than O. lorrettae n. sp. (7-17 vs 13-23) and, like O. mukahensis n. sp., possesses scutes that are spathate rather than elongate. O. tyleri n. sp. is readily distinguished from O. mukahensis n. sp. in its possession of fewer proglottids (7-17 vs. 19-29). The five new species of Orectolobicestus share derived bothridial microthrix features with Phyllobothrium squali Yamaguti, 1952, Thysanocephalum sp., Orygmatobothrium sp., Ruhnkecestus Caira & Durkin, 2006 and species of Paraorygmatobothrium Ruhnke, 1994. Among these taxa, Orectolobicestus most closely resembles Paraorygmatobothrium and Ruhnkecestus in its vitelline fields being interrupted by the ovary and the possession of a scutellate neck.

Animals↗
PubMed2004

Helminthic infections of the liver.

Human helminthic infestation is exceedingly common on a global scale, with as many as 1.5 to 2 billion people affected worldwide. Helminths (parasitic worms) that infect the liver and hepatobiliary system include nematodes (roundworms), cestodes (tapeworms), and trematodes (flatworms or flukes). The majority of morbidity and mortality from these infestations is caused by the host immune response to the larvae or adult worm. Helminthic disease manifestations vary from the extremes of asymptomatic carriage to cirrhosis and decompensated liver disease. Current basic science and clinical research focus on improvements in medical therapy, mass screening and chemoprophylaxis, and the development of preventative vaccine strategies.

Helminthiasis↗
PubMed2006

Parasites of the small intestine.

This paper discusses the most important parasites that inhabit the human small intestine. Beginning with the protozoa and proceeding through the various species of cestodes, nematodes, and trematodes that inhabit the human small bowel, the most important organisms are presented. Possible future developments are discussed along with pathophysiology and treatment in this phylogenic approach. Zoonotic illnesses, those diseases that by their rarity are of little import, and diseases without significant clinical or social implications are beyond the scope of this article and are not discussed.

Animals↗