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PubMed1982

Developmental physiology of cestodes. XVII. Some biological properties of putative "crowding factors" in Hymenolepis diminuta.

A "worm conditioned saline" (WCS) was prepared by incubation of 10-day-old Hymenolepis diminuta (Cestoda: Cyclophyllidea) from infections varying in population density (10, 50, 100 worms per host). Upon subsequent testing on 10-day-old worms from uncrowded (10 worms) infections, WCS prepared with worms from more crowded populations inhibited 3H-thymidine incorporation into DNA to a greater degree than did WCS prepared with worms from less crowded populations. WCS prepared with adult worms (20-30 days old) from crowded (50-worm) infections also inhibited DNA synthesis in 10-day-old cestodes from 10-worm infections. WCS from the anterior ends of adult worms was more inhibitory than WCS prepared with gravid proglottids. The time course of the inhibition was consistent with a G1 block in the cell cycle of the stem cells of the germinative area. The experiments lend support to the hypothesis that these cestodes secrete "crowding factors" that inhibit the growth of other H. diminuta in the same rat.

Acetates↗
PubMed1982

In vitro estimation of glycogen content in three sheep cestodes.

The glycogen content (fresh weight) was biochemically estimated in immature, mature and gravid proglottids of three cestodes, Avitellina centripunctata (Rivolta, 1874), Stilesia globipunctata (Rivolta, 1874) and Moniezia expansa (Rudolphi, 1910), having different niche in the small intestine of sheep. The glycogen gradient was in the order of mature greater than immature greater than gravid proglottids of each species of cestode. Maximum glycogen content was found to be in M. expansa and it was physiologically correlated with the presence of carbon dioxide in the posterior region of the intestine.

Animals↗
PubMedDate not supplied

[The taxonomic status of cestodes with an unusual localization from Antarctic seals].

The great structural diversity in the cestodes Glandicephalus antarticus (Baird, 1853) from the stomach and intestine of the Ross Seal and G. perfoliatus (Railliet et Henry, 1912) from the bile-pancreatic duct of the Weddel Seal was recovered. These two cestodes are moved out of the family Diphyllobothriidae Luhe, 1910 and considered as the new family Glandocephalidae fam. n. within the superfamily Diphyllobothrioidea. Redescriptions of both species, and some indices of invasion rate are provided.

Animals↗
PubMedDate not supplied

[The effect of ionizing radiation on various factors of natural immunity of hamsters under normal conditions and during invasion with the cestode, Hymenolepis diminuta].

Effect of single and chronic irradiation on factors of hamsters natural immunity such as complement, lysozyme and antibodies in norm and in the cestode invasion has been investigated. Significant phase changes in the complement activity level, lysozyme content and specific antibodies titre have been shown to occur in hamster blood under the influence of ionizing radiation. Cestode invasion in irradiated host organism increases the negative effect of ionizing radiation on the hamster immune system.

Animals↗
PubMedDate not supplied

[Comparative characteristics of cestode parenchyma].

A comparative description is given of different connective tissue cells and the character of intercellular substance in the parenchyma of two species of cestodes of the order Pseudophyllidea and 4 species of the order Cyclophyllidea. The parenchyma of the cestodes has been shown to be a complex specialized tissue system evolving divergently. The first distinct morphological differences arise at the family level. The direction of the divergent evolution of the parenchyma depends on the development of certain components of intercellular substance, frequencies of individual types of cells and appearance of specific cellular element in it.

Animals↗
PubMed1996

[Comparative studies on the ultrastructure, homology and analogy of egg envelopes in trematodes and cestodes].

The origin, differentiation and functional ultrastructure of egg envelopes surrounding developing and mature miracidia of Schistosoma mansoni and that of developing and mature coracidia of Bothriocephalus clavibothrium have been examined by means of electron microscopy and cytochemistry. Results obtained on these two species were compared with data from our previous studies on the ultrastructure of egg envelopes in different cyclophyllidean (Hymenolepididae, Taeniidae, Anoplocephalidae, Davaineidae) and proteocephalidean cestodes. In the mature infective egg, the three main egg envelopes (the egg-shell, and the outer and inner envelope) that surround the larvae (miracidia of Digenea, coracidia of Pseudophyllidea, and hexacanths of Cyclophyllidea and Proteocephalidea), show evident similarities in their origin, functional ultrastructure and chemical composition. Conclusions of this comparison, concerning analogy and homology in egg envelopes of trematodes and cestodes, are drawn and discussed.

Animals↗
PubMedDate not supplied

[Parandrya feodorovi gen. n., sp. n.--a new cestode (Cyclophyllidea: Anoplocephalidae) from voles in Siberia].

A new genus and species of the anoplocephalid cestodes, Parandrya feodorovi gen. et sp. n. are described from the Western and Eastern Siberia voles. The new genus Parandrya is distinguished from the genus Andrya Railliet, 1893 by the presence of the cellular form of the uterus. The new genus also differs from other known genera of anoplocephalid cestodes associated with Rodentia, which have a single genital apparatus and cellular uterus, by the transformation of the external receptaculum seminis into the prostatio gland.

Animals↗
PubMed1997

[Helminth fauna of the red fox (Vulpes vulpes LINNE 1758) in south Sachsen-Anhalt--1: Cestodes].

Between January 1993 and November 1994 a total of 1300 red foxes from the administrative districts Halle and Dessau were examined for the presence of Echinococcus multilocularis and other cestodes. Echinococcus multilocularis-infections were detected in only 4 of 1300 (0.3%) foxes. Furthermore the following cestodes were found: Mesocestoides spp. (54.1%), Taenia crassiceps (17.7%), Taenia polyacantha (11.9%), Hydatigera taeniaeformis (0.2%), Taenia serialis (0.15%), Taenia pisiformis (0.15%), not determinable taeniids (9.2%), Dipylidium caninum (0.2%) and Hymenolepis spp. (0.08%).

Animals↗
PubMed1997

[Prevalence of Echinococcus multilocularis and other metacestodes and cestodes in the muskrat (Ondatra zibethicus LINK 1795) in Lower Saxony].

Aim of the study was to examine the prevalence and regional distribution of Echinococcus multilocularis and other metacestodes and cestodes in muskrats in Lower Saxony, Germany. A total of 991 muskrats with similar numbers from all districts of the country were examined between January and December 1995. E. multilocularis metacestodes were found in 4.1% of the muskrats in the liver and other organs of the abdominal cavity. The majority of the E. multilocularis positive animals came from the south of Lower Saxony, where E. multilocularis is endemic, and single animals from the middle or the northern part of the country. All metacestodes found were fertile. Additionally, metacestodes from T. taeniaeformis were found in the livers of 42.3% of the muskrats, metacestodes from T. crassiceps were present in the abdominal cavity of 2.7%, T. polyacantha in 0.4% and T. martis in 3.4% of the animals. Adult cestodes of the family of the Anoplocephalidae were found in the small intestine of 1.5% of the muskrats. Due to autolysis a species differentiation of the latter was not possible.

Abdomen↗
PubMed1976

On cestodes of Passer domesticus I. Choanotaenia, Raillietine and Proparuterina.

An investigation on the cestode fauna of the common sparrow, Passer domesticus (Linnaeus) was carried out for about five years. In all 445 birds were examined during this period and only five species of cestodes were found to parasitize this bird: of these, three are known while two are new forms, the latter are the rarities. This part includes critical accounts of Choanotaenia passerina (Fuhrmann, 1907), Raillietine (R.) galeritae (Skrjabin, 1915) and Proparuterina lali sp. nov. - Choanotaenia passerina (Fuhrmann, 1907) has been previously studied by Fuhrmann (1907), Johnston (1909), Stunkard & Milford (1937) and Kintner (1938). The present study provides additional data. The writers find two rows of rostellar hooks in the present material. Fuhrmann and Johnston reported two rows of rostellar hooks, but Kintner apparently found a single row of rostellar hooks. Variations have been found in the number of testes and extent of cirrus sac. Amongst the previous workers, only Johnston (1909) paid attention to study the protective coverings present around the hexacanth and described two envelopes, but the writers find three. - Raillietine (R.) galeritae (Skrjabin, 1915) has been restudied and redescribed from fresh material. Previously Mahon (1958) studied this species from P. domesticus. The present account includes important variations and some additions too. Suckers have been found to be armed in contradiction to what Mahon stated. Gravid proglottides have been found to develop a velum. Egg capsules contain 3-13 eggs each. Two protective envelopes have been found around the hexacanth. This is the first record of the occurrence of this species in P. domesticus in India. Proparuterina lali sp. nov. is a rare parasite of Passer domesticus. Only one more species viz. P. aruensis Fuhrmann, 1911 is known. The present species differs from P. aruensis in the number and distribution of testes, bilobed nature and median position of ovary, position of vitellarium and of genital pore. The generic diagnosis of Proparuterina Fuhrmann, 1911 has been amended in the light of the morphology of the present species.

Animals↗
PubMed2003

Spermiogenesis in the proteocephalidean cestode Proteocephalus torulosus (Batsch, 1786).

Spermiogenesis of the proteocephalidean cestode Proteocephalus torulosus (Batsch, 1786) was examined for the first time using transmission electron microscopy. Spermiogenesis begins with the formation of a distal cytoplasmic protrusion, a differentiation zone, at the periphery of the early spermatid. This differentiation zone is lined with cortical microtubules and contains two centrioles aligned along the same axis. Subsequently, each centriole is associated with the striated root and the intercentriolar body appears between them. A flagellar bud arises from each centriole, growing later as a free flagellum. Simultaneously, a median cytoplasmic process (MCP) develops distally to the flagella. The two flagella, which are of unequal length, become longer and rotate towards the MCP. At this stage, two arching membranes appear at the base of the differentiation zone. The nucleus elongates and when both flagella are fused with the MCP, the nucleus subsequently migrates into the MCP. Finally, the advanced spermatids detach from a condensing residual cytoplasm at the level of the arching membranes.

Animals↗
PubMed2003

Epidemiology, clinical manifestations and diagnosis of zoonotic cestode infections: an update.

This paper reviews the literature on zoonotic cestode infections with specific reference to the years 1999-2003. The sources and prevalence of various zoonotic tapeworm infections caused by adult and larval stages of the genera Taenia, Echinococcus, Diphyllobothrium, Hymenolepis and Dipylidium continue to be an important cause of morbidity and mortality, not only in most underdeveloped countries but also in industrialized countries, particularly in rural areas or among immigrant groups from endemic areas. The review gives a detailed report on recent molecular epidemiological studies on the taxonomy and phylogenetic variations in Echinococcus granulosus, immunological tests and imaging techniques used in epidemiological surveys and clinical investigations of important adult and larval tapeworm infections of animals and humans. Larval stages or metacestodes of Taenia solium, Echinococcus spp. and pseudophyllidean tapeworms (Spirometra syn. Diphyllobothrium spp.) may reside in various tissues of their intermediate hosts, including humans. In particular, Cysticercus cellulosae (T. solium) and the larvae of E. granulosus, and E. multilocularis, which are predominantly located in the liver, lungs and central nervous system forming various types of cysts, lead to a complex of systemic diseases such as cysticercosis, cystic echinococcosis and alveolar echinococcosis, respectively. Relatively rare clinical manifestations are seen in the muscles, subcutaneous tissue, spleen, kidneys, bones and body cavities.

Animal Diseases↗
PubMed2004

Ultrastructural particularities of the spermatozoon of the cestode Electrotaenia malopteruri (Fritsch, 1886) (Proteocephalidae: Gangesiinae), a parasite of Malapterurus electricus (Siluriformes: Malapteruridae) from the river Nile, Egypt.

The fine structure of the mature spermatozoon of the tapeworm Electrotaenia malopteruri (Fritsch, 1886), a member of a supposedly primitive group of proteocephalidean tapeworms (Proteocephalidae: Gangesiinae), was studied by transmission electron microscopy for the first time. The mature spermatozoon of E. malopteruri is filiform, tapers at both extremities, and contains two axonemes of 9+"1" trepaxonematan type. A helicoidal crested body (60-150 nm thick) is present at the anterior extremity of the gamete. The twisting cortical microtubules (CM) line the periphery of the spermatozoon continuously. The nucleus, a fine cord of moderately condensed chromatin, occupies the middle part (region III) of the spermatozoon. The slightly electron-dense cytoplasm contains electron-dense granules in regions II and III and becomes more electron-dense at the end of region IV. The anterior and posterior extremities of the spermatozoon contain a single axoneme. Two modes of disorganisation of the axoneme at the posterior end of the mature spermatozoa are described for the first time in cestodes. The present data also indicate that the sperm ultrastructure of E. malapteruri shows some characters typical for onchobothriid tetraphyllideans, but it resembles that of Cyclophyllidea in the arrangement of twisting of the CM.

Animals↗
PubMed2004

Characterization of development-related genes for the cestode Bothriocephalus acheilognathi.

Differential gene expression of mature and immature Bothriocephalus acheilognathi cestodes was analyzed using the suppression subtractive hybridization technique. Five mature-associated cDNAs were isolated and characterized. Virtual Northern blot and RT-PCR analyses confirmed that four of the five genes were upregulated in mature parasites. The sequence analysis revealed that one gene encoded the structural protein chorion precursor, and the three encoded functional proteins homologous to yolk ferritin, sodium/hydrogen exchanger and muscin-like protein. Another gene appeared to be specific to B. acheilognathi, encoding a putative metal-bound protein. Although results obtained in the present study are preliminary, the information about the five genes may provide clues for further investigation on the decline in parasite numbers during the maturation of B. acheilognathi.

Amino Acid Sequence↗
PubMed2004

Ultrastructure of the spermatozoon of the anoplocephalid cestode Gallegoides arfaai (Mobedi and Ghadirian, 1977) Tenora and Mas-Coma, 1978, an intestinal parasite of the wood mouse (Apodemus sylvaticus Linnaeus, 1758).

The present work involves an ultrastructural study of the mature spermatozoon of the anoplocephalid cestode Gallegoides arfaai (Mobedi and Ghadirian, 1977) Tenora and Mas-Coma, 1978, obtained from the small intestine of naturally infected wood mice, Apodemus sylvaticus Linnaeus, 1758 (Rodentia, Muridae). The mature spermatozoon of G. arfaai is a filiform cell, tapered at both ends and lacking mitochondria. It is characterized by the presence of a 1,000-nm-long apical cone and two 140-nm-thick crest-like bodies in its anterior extremity. The axoneme, of the 9 + '1' trepaxonematan pattern, lacks a periaxonemal sheath, and disorganization occurs at the level of the nuclear region of the sperm cell. The cortical microtubules form two to four fields according to the different regions of the male gamete. They are twisted at an angle of about 35 degrees , becoming parallel towards the posterior extremity of spermatozoon. The nucleus, spiralled around the axoneme, shows an irregular shape in both longitudinal and cross-sections. Numerous electron-dense granules were observed, which transform into an electron-dense material in the posterior extremity of the cell. Moreover, we describe for the first time the total length of the anterior region of sperm containing the helical crest-like bodies. This anterior extremity measures around 15 mum and presents two helical crest-like bodies of different lengths that describe 13-14 turns around the sperm body. Our ultrastructural results on the G. arfaai spermatozoon are compared with the ultrastructural organization of the spermatozoa of other previously studied species, with particular emphasis on the anoplocephalids.

Animals↗
PubMed1996

Rates of reinfection with Echinococcus granulosus, Taenia hydatigena, taenia ovis and other cestodes in a rural dog population in Uruguay.

A survey was undertaken to determine both the prevalence of, and reinfection rates with Echinococcus granulosus and other cestodes in the Department of Florida, Uruguay. Baseline prevalence was determined in 303 rural dogs which then, in 4 groups, were re-examined 2, 4, 8 or 12 months later. Baseline prevalences for E. granulosus, Taenia hydatigena, Taenia ovis and Dipylidium caninum were 13.2, 13.9, 2.3 and 13.2%, respectively. The frequency distribution of E. granulosus was over-dispersed. Dogs in the population became infected with E. granulosus between 2 and 4 months after treatment (prevalences at 2, 4, 8 and 12 months were 0, 6.8, 18.6 and 27.9%, respectively). There was no indication that there was a predisposition of dogs to infection with the Odds Ratio being 1.0. Dogs were infected with T. hydatigena and D. caninum within 2 months and with T. ovis between 2 and 4 months after treatment. The implications of these different rates of reinfection in the dog population on anthelmintic control strategies against cystic echinococcosis are discussed.

Age Factors↗
PubMed2004

Anthelmintic efficacy of Flemingia vestita (Fabaceae): alterations in glucose metabolism of the cestode, Raillietina echinobothrida.

The root-tuber peel of Flemingia vestita and its active component, genistein, were tested in respect of glucose metabolism in the cestode, Raillietina echinobothrida. Live R. echinobothrida, collected from the intestine of freshly slaughtered domestic fowl, were incubated at 39+/-1 degrees C in defined concentrations of the root-peel crude extract (5 mg/ml), genistein (0.2 mg/ml) and praziquantel (1 microg/ml) in phosphate buffered saline with 1% of dimethyl sulphoxide with simultaneous maintenance of controls. In the treated worms, there was a significant decrease in the glycogen concentration accompanied with the decrease of glucose by 14-32%, whereas the malate concentration increased by 49-134% as compared to controls. Both in controls and treated parasites, however, the pyruvate content was not measurable. While alanine and lactate contents showed a decline by 7-25% in the parasites exposed to all test materials, the lactate efflux into the incubation medium showed 37-71% increase in treatments indicating an overall increase of lactate production in comparison to controls. The results showing a decline in the glycogen and glucose contents and a significant rise in the malate content and lactate efflux under treatment conditions suggest that the energy demand in the parasites possibly got enhanced under stress, though it did not influence a switch over towards aerobic degradation of glucose in the parasites.

Animals↗
PubMed2003

The musk rat (Ondatra zibethicus) as intermediate host of cestodes in the Netherlands.

An investigation on the presence of larval cestodes in musk rats (Ondatra zibethicus) was carried out in two regions of the Netherlands (east Groningen and south Limburg) where in a earlier study foxes with Echinococcus multilocularis were found. A total of 1726 musk rats were dissected (1200 in Groningen, 526 in Limburg). Larval stages of Taenia taeniaeformis were most frequently found (total 44.8%: Groningen 42%, Limburg 51.3%), followed by T. martis (total 6.1%: Groningen 0.7%, Limburg 18.6%). Infections with T. crassiceps (total 0.3%: Groningen 0%, Limburg 1.0%), T. polyacantha (total 0.2%; Groningen 0.3%, Limburg 0%) and E. multilocularis (0.1%: Groningen 0.1%, Limburg 0%) were rare. Infections with T. taeniaeformis were more frequent in adults (71.8%) than in juveniles (34.2%). The same was found for T. martis: adults 15.3%, juveniles 2.5%. This difference was also reflected in the relation between weight of the animals and presence of infection. Heavier animals (>1000 g) were more often infected with T. taeniaeformis (74.1%) than animals less than 1000 g (34.8%). In musk rats weighing less than 500 g (n=155) only 5.2% were infected, but above 1200 g, 82.6%. The highest number of T. taeniaeformis was 28, of T. martis 13, of T. crassiceps >1000 and of T. polyacantha 24. The E. multilocularis was in a very young stage, a few white spots in the liver. Although E. multilocularis infections were exceptional, it is expected that with a rise in the number of infected foxes in the Netherlands the number of infected musk rats will increase.

Age Factors↗