Cestode parasites release extracellular vesicles with microRNAs and immunodiagnostic protein cargo.

PubMed

Ancarola, María Eugenia; Marcilla, Antonio; Herz, Michaela; Macchiaroli, Natalia; Pérez, Matías; Asurmendi, Sebastián; Brehm, Klaus; Poncini, Carolina; Rosenzvit, Mara; Cucher, Marcela

2017-09-01

Intercellular communication is crucial in multiple aspects of cell biology. This interaction can be mediated by several mechanisms including extracellular vesicle (EV) transfer. EV secretion by parasites has been reported in protozoans, trematodes and nematodes. Here we report that this mechanism is present in three different species of cestodes, Taenia crassiceps, Mesocestoides corti and Echinococcus multilocularis. To confirm this we determined, in vitro, the presence of EVs in culture supernatants by transmission electron microscopy. Interestingly, while T. crassiceps and M. corti metacestodes secrete membranous structures into the culture media, similar vesicles were observed in the interface of the germinal and laminated layers of E. multilocularis metacestodes and were hardly detected in culture supernatants. We then determined the protein cargo in the EV-enriched secreted fractions of T. crassiceps and M. corti conditioned media by LC-MS/MS. Among the identified proteins, eukaryotic vesicle-enriched proteins were identified as expected, but also proteins used for cestode disease diagnosis, proteins related to neurotransmission, lipid binding proteins as well as host immunoglobulins and complement factors. Finally, we confirmed by capillary electrophoresis the presence of intravesicular RNA for both parasites and detected microRNAs by reverse transcription-PCR. This is the first report of EV secretion in cestode parasites and of an RNA secretion mechanism. These findings will provide valuable data not only for basic cestode biology but also for the rational search for new diagnostic targets. Copyright © 2017 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Transcriptome profiling of the cysticercus stage of the laboratory model Taenia crassiceps, strain ORF.

PubMed

García-Montoya, Gisela M; Mesa-Arango, Jairo A; Isaza-Agudelo, Juan P; Agudelo-Lopez, Sonia P; Cabarcas, Felipe; Barrera, Luis F; Alzate, Juan F

2016-02-01

Neurocysticercosis (NC) is a serious public health problem mainly in developing countries. NC caused by the cysticercus stage from cestode Taenia solium is considered by the WHO and ITFDE as a potentially eradicable disease. Definitive diagnosis of NC is challenging because of the unspecific clinical manifestations such as the non-definitive evidence presented by neuroimaging (in most cases) and the lack of definitive serological test. Taenia crassiceps (ORF strain) is a cestode closely related to T. solium and it has frequently been used as a source of antigens for immunodiagnostics. A murine model to study host immune response to infection has also been established by using T. crassiceps. Despite the extensive use of T. crassiceps for research, molecular information for this cestode is scarce in public databases. With the aim of providing more extensive information on T. crassiceps biology, an RNA-seq experiment and subsequent bioinformatic transcriptome processing of this cestode parasite mRNA in its cysticercus stage were carried out. A total of 227,082 read/ESTs were sequenced using the 454-GS FLX Titanium technology and assembled into 10,787 contigs. This transcriptome dataset represents new and valuable molecular information of the cestode T. crassiceps (ORF). This information will substantially improve public information and will help to achieve a better understanding of the biology of T. crassiceps and to identify target proteins for serodiagnosis and vaccination. Copyright © 2015 Elsevier B.V. All rights reserved.

Occurrence of Cyathocephalus truncatus (Cestoda) in fishes of the Great Lakes with emphasis on its occurrence in round gobies (Neogobius melanostomus) from Lake Huron

USGS Publications Warehouse

French, John R. P.; Muzzall, Patrick M.; Adams, Jean V.; Johnson, Kendra L.; Flores, Angela E.; Winkel, Andrea M.

2005-01-01

Cyathocephalus truncatus is a pathogenic cestode that is common in many Laurentian Great Lakes fish species, but the depth distribution of this cestode has not been studied. Cyathocephalus truncatus has been reported from 21 fish species and one hybrid representing seven orders and nine families in Lakes Superior, Michigan, Huron, and Ontario. We examined the intestinal contents of six species of fish collected in Michigan waters of Lake Huron, from DeTour to Harbor Beach, in 2001 to 2003 for the presence of this cestode species. Cyathocephalus truncatus was found in five native fish species and the exotic round goby. Prevalence (52%) and mean intensity (4.6 cestodes per infected fish) were highest in bloaters. This is the first reported occurrence of this cestode in round gobies from the Great Lakes. None of the gobies trawled from Lake Huron at depths of 27 to 46 m were infected, but prevalence and intensity of infection in round gobies increased significantly with depth from 55 to 73 m. Our diet study of round gobies indicated that they preyed heavily on amphipods (Diporeia hoyi) at depths of 55 to 73 m. Cyathocephalus truncatus was found in eight of 605 D. hoyi obtained by Ponar grab sampling. This suggests that C. truncatus eggs may be released from infected gobies and sink to deep basins with silt bottoms where D. hoyi occur.

Diversification and Species Boundaries of Rhinebothrium (Cestoda; Rhinebothriidea) in South American Freshwater Stingrays (Batoidea; Potamotrygonidae)

PubMed Central

Reyda, Florian B.; Marques, Fernando P. L.

2011-01-01

Background Neotropical freshwater stingrays (Batoidea: Potamotrygonidae) host a diverse parasite fauna, including cestodes. Both cestodes and their stingray hosts are marine-derived, but the taxonomy of this host/parasite system is poorly understood. Methodology Morphological and molecular (Cytochrome oxidase I) data were used to investigate diversity in freshwater lineages of the cestode genus Rhinebothrium Linton, 1890. Results were based on a phylogenetic hypothesis for 74 COI sequences and morphological analysis of over 400 specimens. Cestodes studied were obtained from 888 individual potamotrygonids, representing 14 recognized and 18 potentially undescribed species from most river systems of South America. Results Morphological species boundaries were based mainly on microthrix characters observed with scanning electron microscopy, and were supported by COI data. Four species were recognized, including two redescribed (Rhinebothrium copianullum and R. paratrygoni), and two newly described (R. brooksi n. sp. and R. fulbrighti n. sp.). Rhinebothrium paranaensis Menoret & Ivanov, 2009 is considered a junior synonym of R. paratrygoni because the morphological features of the two species overlap substantially. The diagnosis of Rhinebothrium Linton, 1890 is emended to accommodate the presence of marginal longitudinal septa observed in R. copianullum and R. brooksi n. sp. Patterns of host specificity and distribution ranged from use of few host species in few river basins, to use of as many as eight host species in multiple river basins. Significance The level of intra-specific morphological variation observed in features such as total length and number of proglottids is unparalleled among other elasmobranch cestodes. This is attributed to the large representation of host and biogeographical samples. It is unclear whether the intra-specific morphological variation observed is unique to this freshwater system. Nonetheless, caution is urged when using morphological discontinuities to delimit elasmobranch cestode species because the amount of variation encountered is highly dependent on sample size and/or biogeographical representation. PMID:21857936

First Report of an Adult Tapeworm (Cestoda: Diphyllobothriidea) in a Southern Sea Otter (Enhydra lutris nereis).

PubMed

Young, Colleen; Miller, Melissa A; Kuchta, Roman; Brabec, Jan; Newsome, Seth D; Dailey, Murray

2017-10-01

We present a novel case of an intestinal cestode infection in a southern sea otter (Enhydra lutris nereis). The cestode species Diphyllobothrium tetrapterum (syn. Diplogonoporus tetrapterus) was confirmed genetically. Stable isotope analysis of whiskers collected from the sea otter did not confirm the consumption of fish as the route of exposure.

Molecular systematics and Holarctic phylogeography of cestodes of the genus Anoplocephaloides Baer, 1923 s. s. (Cyclophyllidea: Anoplocephalidae) in lemmings (Lemmus, Synaptomys)

USDA-ARS?s Scientific Manuscript database

The present molecular-systematic and phylogeographic analysis is based on sequences of cytochrome c oxidase subunit 1 (cox1) (mtDNA) and 28S ribosomal DNA, and includes 59 isolates of cestodes of the genus Anoplocephaloides Baer, 1923 s. s. (Cyclophyllidea, Anoplocephalidae) from arvicoline rodents ...

Influence of geographical scale on the detection of density dependence in the host-parasite system, Arvicola terrestris and Taenia taeniaeformis.

PubMed

Deter, J; Berthier, K; Chaval, Y; Cosson, J F; Morand, S; Charbonnel, N

2006-04-01

Infection by the cestode Taenia taeniaeformis was investigated within numerous cyclic populations of the fossorial water vole Arvicola terrestris sampled during 4 years in Franche-Comté (France). The relative influence of different rodent demographic parameters on the presence of this cestode was assessed by considering (1) the demographic phase of the cycle; (2) density at the local geographical scale (<0.1 km2); (3) mean density at a larger scale (>10 km2). The local scale corresponded to the rodent population (intermediate host), while the large scale corresponded to the definitive host population (wild and feral cats). General linear models based on analyses of 1804 voles revealed the importance of local density but also of year, rodent age, season and interactions between year and season and between age and season. Prevalence was significantly higher in low vole densities than during local outbreaks. By contrast, the large geographical scale density and the demographic phase had less influence on infection by the cestode. The potential impacts of the cestode on the fitness of the host were assessed and infection had no effect on the host body mass, litter size or sexual activity of voles.

Novel PCRs for differential diagnosis of cestodes.

PubMed

Roelfsema, Jeroen H; Nozari, Nahid; Pinelli, Elena; Kortbeek, Laetitia M

2016-02-01

Cestodes or tapeworms belong to a diverse group of helminths. The adult Taenia saginata and Taenia solium tapeworm can infest the human gut and the larval stage of Echinococcus spp. and T. solium can infect tissues of the human body, causing serious disease. Molecular diagnostics can be performed on proglottids, eggs and on cyst fluids taken by biopsy. Detection of cestodes when a helminthic infection is suspected is of vital importance and species determination is required for appropriate patient care. For routine diagnostics a single test that is able to detect and type a range of cestodes is preferable. We sought to improve our diagnostic procedure that used to rely on PCR and subsequent sequencing of the Cox1 and Nad1 genes. We have compared these PCRs with novel PCRs on the 12S rRNA and Nad5 gene and established the sensitivity and specificity. A single PCR on the 12S gene proved to be very suitable for detection and specification of Taenia sp. and Echinococcus sp. Both targets harbour enough polymorphic sites to determine the various Echinococcus species. The 12S PCR was most sensitive of all tested. Copyright © 2015 Elsevier Inc. All rights reserved.

Intestinal cestodes.

PubMed

Webb, Camille; Cabada, Miguel M

2017-10-01

Cestodes infections in humans are among the most prevalent parasitosis worldwide. Although tapeworm infection is often asymptomatic, they can be associated with a range of symptoms. The landscape of cestode infections is changing with rapid diagnosis techniques and advanced molecular diagnosis aiding in identification of species specific epidemiology. Traditional descriptions of species by location have been challenged with molecular diagnostic techniques, which show variation in distribution of species, thought to be because of globalization and importation of disease. Epidemiology, molecular diagnostic techniques. Infection by tapeworms is often asymptomatic or accompanied by mild symptoms though can occasionally cause severe disease and contribute to anemia and malnutrition. Tapeworm infection is most prevalent in resource-poor countries but the distribution is worldwide. Epidemiology of infection is changing because of molecular diagnostics, which allow more accurate tracking of species.

Digestion and digestive-transport surfaces in cestodes and their fish hosts.

PubMed

Izvekova, G I; Kuperman, B I; Kuz'mina, V V

1997-12-01

The structural and functional organization of digestive-transport surfaces in some lower cestodes and their fish hosts was studied. It has been shown that the ultrastructure of cestode microtriches and fish enterocyte microvilli being the basis of membrane-linked digestion is quite similar. These organelles increase the digestive-transport surfaces both in helminths and fishes. However, the hydrolytic enzyme activity in helminths is usually 2-4 times lower than that of the fishes. Desorption (adsorption) characteristics of various hydrolases in helminths and fishes are also different. In helminths the easily desorbed fraction of each enzyme is always more abundant than in fishes. In contrast, the intensity of transport processes in helminths is higher when compared with fishes. The adaptation of digestive-transport surfaces and enzyme systems to feeding conditions is discussed.

Efficacy against nematode and cestode infections and safety of a novel topical fipronil, (S)-methoprene, eprinomectin and praziquantel combination product in domestic cats under field conditions in Europe.

PubMed

Rehbein, Steffen; Capári, Balazs; Duscher, Georg; Keidane, Dace; Kirkova, Zvezdelina; Petkevičius, Saulius; Rapti, Dhimiter; Wagner, Annegret; Wagner, Thomas; Chester, S Theodore; Rosentel, Joseph; Tielemans, Eric; Visser, Martin; Winter, Renate; Kley, Katrin; Knaus, Martin

2014-04-28

A novel topical combination product (BROADLINE(®), Merial) composed of fipronil, (S)-methoprene, eprinomectin and praziquantel was evaluated for safety and efficacy against nematode and cestode infections in domestic cats. The study comprised a multi-centre, positive control, blinded, field study, using a randomized block design based on order of presentation for allocation. In total 196 client-owned cats, confirmed as positive for naturally acquired infections of nematodes and/or cestodes by pre-treatment faecal examination, were studied in seven countries in Europe. Pre-treatment faecal examination revealed the presence of Toxocara, hookworm, Capillaria and/or spirurid nematode infections in 129, 73, 33 or 1 cat(s), respectively; infections with taeniid and Dipylidium cestodes were demonstrated in 39 and 17 cats, respectively. Cats were allocated randomly to one of two treatments in a ratio of 2, topical fipronil (8.3%, w/v), (S)-methoprene (10%, w/v), eprinomectin (0.4%, w/v) and praziquantel (8.3%, w/v) (BROADLINE(®), Merial; 130 cats); and 1, topical PROFENDER(®) Spot-On (Bayer; 66 cats) and treated once on Day 0. For evaluation of efficacy, two faecal samples were collected, one prior to treatment (Day -4 ± 4 days) and one at the end of the study (Day 14 ± 5 days). These were examined for fecal forms of nematode and cestode parasites. For evaluation of safety, cats were examined by a veterinarian before treatment and at the end of the study, and cat owners recorded the health status of their cats daily until the end of the study. For cats treated with Broadline(®), the efficacy was >99.9%, 100%, and 99.6% for Toxocara, hookworms, and Capillaria, respectively; and the efficacy was >99.9%, >99.9%, and 98.5%, respectively, for the cats treated with Profender(®) (p<0.001 for all nematodes and both treatments). Efficacy was 100% for both cestodes for both treatments (p<0.001). No treatment related adverse experiences were observed throughout the study. For both treatments, every cat that completed the study was given a safety score of 'excellent' for both local and systemic evaluations. The topical combination product of fipronil, (S)-methoprene, eprinomectin and praziquantel was shown to have an excellent safety profile and demonstrated high levels of efficacy when administered once as topical solution to cats infected with nematodes and cestodes under field conditions. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Annotated checklist of fish cestodes from South America

PubMed Central

Alves, Philippe V.; de Chambrier, Alain; Scholz, Tomáš; Luque, José L.

2017-01-01

Abstract An exhaustive literature search supplemented by a critical examination of records made it possible to present an annotated checklist of tapeworms (Cestoda) that, as adults or larvae (metacestodes), parasitize freshwater, brackish water and marine fishes, i.e. cartilaginous and bony fishes, in South America. The current knowledge of their species diversity, host associations and geographical distribution is reviewed. Taxonomic problems are discussed based on a critical evaluation of the literature and information on DNA sequences of individual taxa is provided to facilitate future taxonomic and phylogenetic studies. As expected, the current knowledge is quite uneven regarding the number of taxa and host-associations reported from the principal river basins and marine ecoregions. These differences may not only reflect the actual cestode richness but may also be due to the research effort that has been devoted to unravelling the diversity of these endoparasitic helminths in individual countries. A total of 297 valid species, 61 taxa identified to the generic level, in addition to unidentified cestodes, were recorded from 401 species of fish hosts. Among the recognized cestode orders, 13 have been recorded in South America, with the Onchoproteocephalidea displaying the highest species richness, representing c. 50% of all species diversity. The majority of records include teleost fish hosts (79%) that harbour larval and adult stages of cestodes, whereas stingrays (Myliobatiformes) exhibit the highest proportion of records (39%) among the elasmobranch hosts. Fish cestodes are ubiquitous in South America, being mostly recorded from the Warm Temperate Southeastern Pacific (WTSP; 31%) for marine hosts and the Amazon River basin (45%) for freshwater ones. The following problems were detected during the compilation of literary data: (i) unreliability of many records; (ii) poor taxonomic resolution, i.e. identification made only to the genus or even family level; (iii) doubtful host identification; and (iv) the absence of voucher specimens that would enable us to verify identification. It is thus strongly recommended to always deposit representative specimens in any type of studies, including faunal surveys and ecological studies. An analysis of the proportion of three basic types of studies, i.e. surveys, taxonomic and ecological papers, has shown a considerable increase of ecological studies over the last decade. PMID:28331385

Annotated checklist of fish cestodes from South America.

PubMed

Alves, Philippe V; de Chambrier, Alain; Scholz, Tomáš; Luque, José L

2017-01-01

An exhaustive literature search supplemented by a critical examination of records made it possible to present an annotated checklist of tapeworms (Cestoda) that, as adults or larvae (metacestodes), parasitize freshwater, brackish water and marine fishes, i.e. cartilaginous and bony fishes, in South America. The current knowledge of their species diversity, host associations and geographical distribution is reviewed. Taxonomic problems are discussed based on a critical evaluation of the literature and information on DNA sequences of individual taxa is provided to facilitate future taxonomic and phylogenetic studies. As expected, the current knowledge is quite uneven regarding the number of taxa and host-associations reported from the principal river basins and marine ecoregions. These differences may not only reflect the actual cestode richness but may also be due to the research effort that has been devoted to unravelling the diversity of these endoparasitic helminths in individual countries. A total of 297 valid species, 61 taxa identified to the generic level, in addition to unidentified cestodes, were recorded from 401 species of fish hosts. Among the recognized cestode orders, 13 have been recorded in South America, with the Onchoproteocephalidea displaying the highest species richness, representing c. 50% of all species diversity. The majority of records include teleost fish hosts (79%) that harbour larval and adult stages of cestodes, whereas stingrays (Myliobatiformes) exhibit the highest proportion of records (39%) among the elasmobranch hosts. Fish cestodes are ubiquitous in South America, being mostly recorded from the Warm Temperate Southeastern Pacific (WTSP; 31%) for marine hosts and the Amazon River basin (45%) for freshwater ones. The following problems were detected during the compilation of literary data: (i) unreliability of many records; (ii) poor taxonomic resolution, i.e. identification made only to the genus or even family level; (iii) doubtful host identification; and (iv) the absence of voucher specimens that would enable us to verify identification. It is thus strongly recommended to always deposit representative specimens in any type of studies, including faunal surveys and ecological studies. An analysis of the proportion of three basic types of studies, i.e. surveys, taxonomic and ecological papers, has shown a considerable increase of ecological studies over the last decade.

Efficacy of a novel topical fipronil, (S)-methoprene, eprinomectin and praziquantel combination against naturally acquired intestinal nematode and cestode infections in cats.

PubMed

Knaus, Martin; Abu-Madi, Marawan A; Ibarra-Velarde, Froylán; Kok, Dawie J; Kusi, Ilir; Postoli, Rezart; Chester, S Theodore; Rosentel, Joseph; Alva, Roberto; Irwin, Jennifer; Visser, Martin; Winter, Renate; Rehbein, Steffen

2014-04-28

The efficacy of a novel topical combination formulation of fipronil, (S)-methoprene, eprinomectin and praziquantel against naturally acquired intestinal nematode and cestode infections in cats was evaluated in seven negative control, blinded studies. Cats were selected based on a pre-treatment faecal examination indicating a patent infection with at least hookworms (two studies), Toxocara ascarids (one study), taeniid cestodes (two studies) or Dipylidium cestodes (two studies). In each study, cats were assigned randomly to blocks of two animals each, based on decreasing pre-treatment body weight and were randomly allocated to one of two groups of six to 12 cats: untreated (control) or treated with topical fipronil (8.3%, w/v), (S)-methoprene (10%, w/v), eprinomectin (0.4%, w/v) and praziquantel (8.3%, w/v) (BROADLINE(®), Merial) at 0.12 mL/kg body weight (providing a minimum of 10mg fipronil+12 mg S-methoprene+0.5mg eprinomectin+10mg praziquantel per kg body weight). The topical treatment was administered directly on the skin in the midline of the neck in a single spot once on Day 0. For parasite recovery and count, cats were euthanized humanely and necropsied seven or ten days after treatment. A single treatment with the novel topical combination product provided 91% efficacy against Ancylostoma braziliense, ≥ 99% efficacy against Ancylostoma tubaeforme, and >97% efficacy against Toxocara cati. Similarly, excellent efficacy was established against Taenia taeniaeformis, Dipylidium caninum and Diplopylidium spp. as demonstrated by >97% and up to 100% reductions of cestode counts in the treated cats when compared to the untreated controls (P<0.01). All cats accepted the treatment well based on health observations post-treatment and daily health observations. No adverse experiences or other health problems were observed throughout the studies. The results of this series of controlled studies demonstrated high efficacy and excellent acceptability of the novel topical combination formulation of fipronil, (S)-methoprene, eprinomectin and praziquantel against a broad range of feline intestinal nematode and cestode infections. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Four new cestode species from the spiral intestine of the round stingray, Urobatis halleri, in the Northern Gulf of California, Mexico

Treesearch

Megan M. Friggens; Donald W. Duszynski

2005-01-01

The spiral intestines of 40 specimens of Urobatis halleri from the northern Gulf of California, Mexico, were examined for cestodes. Four new species, Rhinebothrium chollaensis n. sp., Rhinebothrium gravidum n. sp., Eutetrarhynchus cortezensis n. sp., and Prochristianella minima n. sp., are described. This is the first record of these 3 genera in the Gulf of...

Fine structure of the uteri in two hymenolepidid tapeworm Skrjabinacanthus diplocoronatus and Urocystis prolifer (Cestoda: Cyclophyllidea) parasitic in shrews that display different fecundity of the strobilae.

PubMed

Korneva, Janetta V; Kornienko, Svetlana A; Jones, Malcolm K

2012-10-01

Adult specimens of Skrjabinacanthus diplocoronatus and Urocystis prolifer were investigated by light and transmission electron microscopy, and data on the uterine organization in these species are presented. The interrelationships of morphological changes of the uterus and developing eggs on the one hand with fecundities of the strobilae of cyclophyllidean cestodes on the other hand are investigated. The development of the excretory system forming a network of excretory ducts close to the uterus is characteristic of S. diplocoronatus. Numerous excretory ducts are located near the uterus or contact the uterine epithelium and are also found in uterine cords. Accumulation of lipids is observed in the cavity of excretory ducts, in muscular cells, and in the lumen of the uterus as well as in the developing eggs. This species displays the largest fecundity among cestode parasites of the shrew. U. prolifer has one of the lowest fecundities among cestodes from shrews. A small amount of lipids found in cells of gravid proglottids could serve as a supply of nutrients. It seems that some cestodes with great fecundity possess specific paths by which eggs are supplied with nutrients. As a result, diverse modifications of the uterus in Cyclophyllidea are formed.

Efficacy of a topical combination of fipronil, (S)-methoprene, eprinomectin and praziquantel (Broadline(®)) against naturally acquired infections with cestodes of the genus Joyeuxiella in cats.

PubMed

Schuster, Rolf K; Mustafa, Murad Basheer; Baskar, Jagadeesan Vijay; Rosentel, Joseph; Chester, S Theodore; Knaus, Martin

2016-07-01

Cats are host to dipylidiid cestodes of the genera Diplopylidium, Dipylidium and Joyeuxiella. Broadline(®), a topical broad-spectrum combination parasiticide containing fipronil (8.3 % w/v), (S)-methoprene (10 % w/v), eprinomectin (0.4 % w/v) and the cestocide praziquantel (8.3 % w/v), has previously been shown to be efficacious against Dipylidium caninum and Diplopylidium spp. in cats. To evaluate its efficacy against Joyeuxiella species, a blinded clinical efficacy study was conducted according to GCP. All cats had evidence for naturally acquired dipylidiid cestode infection as confirmed by pre-treatment examination. Cats were allocated randomly to two groups of 13 cats each based on bodyweight: Control (untreated) and Broadline(®) at 0.12 mL/kg bodyweight administered once topically. Based on the comparison of helminth counts in the treated and untreated cats seven days post treatment, Broadline(®) demonstrated >99 % efficacy (p < 0.01) against mature J. fuhrmanni and J. pasqualei, with 11 and 13 of the untreated cats harbouring 1 to 102 or 2 to 95 cestodes, respectively. In addition, parasite counts indicated 95.9 % efficacy (p = 0.006) against the rictularoid nematode Pterygodermatites cahirensis.

The molecular mechanisms of larval cestode development: first steps into an unknown world.

PubMed

Brehm, Klaus; Spiliotis, Markus; Zavala-Góngora, Ricardo; Konrad, Christian; Frosch, Matthias

2006-01-01

Several hundred million years ago, the free-living ancestors of all extant helminth parasites decided to colonize entirely new habitats, the bodies of other metazoan animals. As a consequence of the resulting adaptation processes, they evolved highly complex life-cycles in which many developmental transitions were initiated and controlled by host-derived signals. Understanding the molecular basis of the original developmental mechanisms, and the modifications that occurred during co-evolution with the host, is not only fundamental to our understanding of parasitism but also highly relevant for the design of anti-parasitic drugs and vaccines. In the past several years, molecular investigations on parasitic nematode and trematode development have made considerable progress and, supported by respective genome sequencing projects and emerging methods of genetic manipulation, will be a flourishing field in the years to come. We consider it time that corresponding studies are also pushed for the third large group of parasitic helminths, the cestodes. Here, we review the first experimental steps into that area, which have been undertaken recently. We report on cestode genomics, the identification of signaling factors associated with larval development, and the establishment as well as improvement of in vitro cultivation systems by which cestode life-cycles can be studied in the laboratory.

The effects of different plant extracts on intestinal cestodes and on trematodes.

PubMed

Abdel-Ghaffar, Fathy; Semmler, Margit; Al-Rasheid, Khaled A S; Strassen, Bianca; Fischer, Katja; Aksu, Gülendem; Klimpel, Sven; Mehlhorn, Heinz

2011-04-01

In the present study, chloroform, aqueous, (polyethylene glycol/propylene carbonate) PEG/PC extracts were made from coconut, onion, garlic, fig, date tree, chicory, ananas, and cistrose. These extracts were tested in vivo and in vitro on their anthelmintic activity against cestodes (Hymenolepis diminuta, H. microstoma, Taenia taeniaeformis) and trematodes (Fasciola hepatica, Echinostoma caproni). In all in vitro tests, the target parasites died. It turned out that the treatment of mice and rats with a combination of onion and coconut extracts (with PEG/PC) eliminated all cestodes from their final hosts. In addition, the same composition was effective against the intestinal fluke E. caproni, but not against the liver fluke F. hepatica in the final host, while both worms were killed in vitro. Inoculation of fluids of coconut eliminated T. taeniaeformis tapeworms from naturally infected cats. This goal was not reached with oil of cistrose.

A case of Diphyllobothrium nihonkaiense infection successfully treated by oral administration of Gastrografin.

PubMed

Yoshida, M; Hasegawa, H; Takaoka, H; Miyata, A

1999-08-01

A diphyllobothriid cestode infection found in a 54-year-old male residing in Oita, Japan, was successfully treated by oral administration of Gastrografin in combination with a intramuscular injection of Vagostigmin. The strobila expelled was 6.14 m long with a scolex, and morphologically identical with Diphyllobothrium nihonkaiense except unusual ovaries of which posterior horns were confluent in each proglottid. This is the first case of treatment of cestode infection by oral administration of Gastrografin.

Effect of Intestinal Tapeworm Clestobothrium crassiceps on Concentrations of Toxic Elements and Selenium in European Hake Merluccius merluccius from the Gulf of Lion (Northwestern Mediterranean Sea).

PubMed

Torres, Jordi; Eira, Catarina; Miquel, Jordi; Ferrer-Maza, Dolors; Delgado, Eulàlia; Casadevall, Margarida

2015-10-28

The capacity for heavy metal bioaccumulation by some fish parasites has been demonstrated, and their contribution to decreasing metal concentrations in tissues of parasitized fish has been hypothesized. The present study evaluated the effect of the cestode Clestobothrium crassiceps on the accumulation of trace elements in 30 European hake, Merluccius merluccius, in Spain (half of them infested by C. crassiceps). Tissue samples from all M. merluccius and specimens of C. crassiceps from the infected hakes were collected and stored until element analysis by inductively coupled plasma mass spectrometry (ICP-MS). Arsenic, mercury, and selenium were generally present in lower levels in the cestode than in all hake tissues. The mean value of the muscular Se:Hg molar ratio in the infested subsample was higher than that in hakes without cestodes. Values indicate that the edible part of infested hakes presents a lower amount of Cd and Pb in relation to noninfested hakes.

The anthelmintic efficacy of natural plant cysteine proteinases against the equine tapeworm, Anoplocephala perfoliata in vitro.

PubMed

Mansur, F; Luoga, W; Buttle, D J; Duce, I R; Lowe, A E; Behnke, J M

2016-09-01

Papaya latex has been demonstrated to be an efficacious anthelmintic against murine, porcine, ovine and canine nematode parasites, and even those infecting poultry, and it has some efficacy against rodent cestodes. The active ingredients of papaya latex are known to be cysteine proteinases (CPs). The experiments described in this paper indicate that CPs in papaya latex, and also those in pineapples, are highly efficacious against the equine cestode Anoplocephala perfoliata in vitro, by causing a significant reduction in motility leading to death of the worms. The susceptibility of A. perfoliata to damage by CPs was considerably greater than that of the rodent cestodes Hymenolepis diminuta and H. microstoma. Our results are the first to report anthelmintic efficacy of CPs against an economically important equine helminth. Moreover, they provide further evidence that the spectrum of activity of CPs is not restricted to nematodes and support the idea that these plant-derived enzymes can be developed into useful broad-spectrum anthelmintics.

Evaluation of the efficacy of emodepside+praziquantel topical solution against cestode (Dipylidium caninum, Taenia taeniaeformis, and Echinococcus multilocularis) infections in cats.

PubMed

Charles, S D; Altreuther, G; Reinemeyer, C R; Buch, J; Settje, T; Cruthers, L; Kok, D J; Bowman, D D; Kazacos, K R; Jenkins, D J; Schein, E

2005-10-01

Emodepside+praziquantel topical solution was developed to provide broad-spectrum anthelmintic activity against gastrointestinal parasites in cats. Eight controlled studies were conducted to evaluate the efficacy of a topical solution of emodepside (3 mg/kg) and praziquantel (12 mg/kg) (Profender, BayerAG, Leverkusen, Germany) against feline infections with three species of cestodes. Studies featured naturally acquired infections of Dipylidium caninum or Taenia taeniaeformis, or experimental infections with Echinococcus multilocularis that were placebo-controlled, randomized and blinded. Cats were euthanatized and necropsied between 2 and 11 days after treatment, depending on the target parasite. The efficacy of emodepside+praziquantel topical solution was 100% against D. caninum and T. taeniaeformis, and 98.5- 100% against E. multilocularis. No significant systemic or local adverse reactions to treatment were noted in cats that received the combination. Topical treatment of cats with emodepside+praziquantel topical solution was safe and highly effective against cestode infections.

Mucocutaneous manifestations of helminth infections: Trematodes and cestodes.

PubMed

Lupi, Omar; Downing, Christopher; Lee, Michael; Bravo, Francisco; Giglio, Patricia; Woc-Colburn, Laila; Tyring, Stephen K

2015-12-01

In the 21st century, despite increased international travel for vacation, work, and medical missions and immigration into the United States, there is little published in the dermatology literature regarding the cutaneous manifestations of helminth infections. It has been estimated that 20% to 70% of international travelers suffer from some travel-related health problem. Approximately 17% of travelers seek medical care because of cutaneous disorders, many related to infectious etiologies. This review will focus on cutaneous diseases caused by helminth infections. Part I of the review focused on nematode infections; part II will focus on trematode and cestode infections. Nematodes are roundworms that cause diseases with cutaneous manifestations, such as cutaneous larval migrans, onchocerciasis, filariasis, gnathostomiasis, loiasis, dracunculiasis, strongyloidiasis, ascariasis, streptocerciasis, dirofilariasis, and trichinosis. Tremadotes, also known as flukes, cause schistosomiasis, paragonimiasis, and fascioliasis. Cestodes (tapeworms) are flat, hermaphroditic parasites that cause diseases such as sparganosis, cysticercosis, and echinococcus. Copyright © 2014 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

A new genus and species of cestode (Rhinebothriidea) from Mobula kuhlii (Rajiformes: Mobulidae) from Malaysian Borneo.

PubMed

Eyring, Kathryn L; Healy, Claire J; Reyda, Florian B

2012-06-01

The cestode fauna of the shortfin devilray, Mobula kuhlii (Müller & Henle, 1841) was examined for the first time. The work resulted in the discovery of a new genus and species of rhinebothriidean tapeworm. Crassuseptum pietrafacei, n. gen. n. sp. is erected here on the basis of its unique scolex and proglottid morphology. Histological sections and examination by light and scanning electron microscopy demonstrated that this new genus differs from all other rhinebothriidean genera in its possession of bothridia in which the proximal and distal sides are confluent, i.e., not separated by a rim of tissue, and in its possession of testes that extend to the posterior margin of the ovary. This new species is characterized in part by its possession of stalked, elongate bothridia lacking lateral constrictions, with 13-15 prominent transverse bothridial septa and 4 reduced transverse septa, craspedote proglottids, each with 2-3 layers of testes in cross section, and a vas deferens that joins the cirrus sac at its anterior margin. Histological and optical sections through bothridial septa revealed that the transverse septa are formed by septal muscles separate from bothridial radial musculature, extending from the anterior side to the posterior side of each septum. This is only the second species rhinebothriidean cestode reported from mobulids. This study adds to the number of new species and genera of elasmobranch cestodes discovered off of the island of Borneo.

Cestode parasites: application of in vivo and in vitro models for studies on the host-parasite relationship.

PubMed

Siles-Lucas, Mar; Hemphill, Andrew

2002-01-01

Cestode worms, commonly also known as 'flat' worms or tapeworms, are an important class of endoparasitic organisms. In order to complete their life cycle, they infect intermediate and definitive hosts in succession, through oral ingestion of eggs or larvae, respectively. Serious disease in humans or other mammalian hosts is mostly caused by the larval stages. Echinococcus spp. and Taenia spp. have been extensively investigated in the laboratory due to the fact that they represent important veterinary medical challenges and also cause grave diseases in humans. In contrast, Hymenolepis spp. and Mesocestoides spp. infections are relatively rare in humans, but these parasites have been extensively studied because their life cycle stages can be easily cultured in vitro, and can also be conveniently maintained in laboratory animal hosts. Thus they are more easily experimentally accessible, and represent important models for investigating the various aspects of cestode biology. This review will focus on in vitro and in vivo models which have been developed for studies on the host-parasite relationship during infection with Echinococcus, Taenia, Hymenolepis, Mesocestoides and Spirometra, and will cover the use of these models to investigate the morphology and ultrastructure of respective genera, the immunological relationship with the host and the development of vaccination approaches, as well as applications of these models for studies on parasite metabolism, physiology and gene expression. In addition, the use of these models in the development of chemotherapeutic measures against cestode infections is reviewed.

Helminth parasites of spotted sandpipers, Actitis macularius (Charadriiformes), from Belize, Texas, and Montana.

PubMed

Canaris, Albert G; Kinsella, John M; Didyk, Andy S

2009-12-01

In total, 70 spotted sandpipers, Actitis macularius, were examined for helminth parasites; 47 from Belize, 18 from Texas, and 5 from Montana. The compound communities consisted of 10 species of helminths for Belize, 5 for Texas, and 6 for Montana, for a total of 17 different species. The most prevalent and abundant helminths for Belize were 3 microphallid trematodes, Paramaritremopsis solielangi, Levinseniella carteretensis, and Microphallus kinsellai; for Texas, the cestodes Kowalewskiella cingulifera and Choanotaenia cayennensis; and for Montana, the cestodes Anomotaenia hypoleuci and K. cingulifera. The cestode K. cingulifera was the only species recorded from all 3 localities. The cestode A. hypoleuci was the only specialist. Characteristics for helminth compound communities from the 3 localities were similar in terms of low mean species richness, medium diversity, and in uneven parasite distribution. Infracommunities were species poor for all 3 localities. For the Belize sample, only 6 of the 47 hosts harbored as many as 3 helminth species, and only 1 harbored more, at 5 species. Only 1 host harbored as many as 3 species in the sample from Texas, and a single host harbored a high of 4 species for Montana. There were no significant differences for mean species richness or mean abundance among the 3 localities. There were no significant differences for species richness or mean abundance between the combined freshwater sample from Texas and Montana and the marine sample from Belize. There were no significant positive or negative associations between pairs of helminth species.

Helminth parasite communities in anuran amphibians of Kalesar Wildlife Sanctuary (Haryana), India.

PubMed

Rizvi, Anjum N; Bhutia, Pasang T

2010-10-01

Helminth parasite fauna in anuran amphibia were investigated during the general faunistic surveys of Kalesar Wildlife Sanctuary, situated in Haryana state. Three species of amphibian hosts were found to harbour 12 genera of helminth parasites. The prevalence, intensity and abundance were studied. Euphlyctis cyanophlyctis harboured maximum parasite species followed by Fejervarya limnocharis and Duttaphrynus melanostictus. In E. cyanophlyctis, among nematode parasites, the genus Camallanus was most prevalent followed by Cosmocerca and Cosmocercoides, whereas, Rhabdias and Aplectana were the least prevalent genera. Among trematode parasites, Ganeo was the most prevalent genus and least was Diplodiscus. Acanthocephalus was recovered only once and no cestode infection was found. In F. limnocharis, the most prevalent nematode genus was Oxysomatium, followed by Cosmocerca and the only trematode recorded was Ganeo, whereas, cestode Proteocephalus was also recovered once. In D. melanostictus, only two nematode genera were recovered of which Oxysomatium was dominant followed by Cosmocerca. The helminth parasite community in anuran amphibia of Kalesar WLS comprised 52.9% of nematodes, 46.2% of trematodes, 0.58% cestodes and 0.29% acanthocephala.

The trypanorhynch cestode fauna of Borneo.

PubMed

Schaeffner, Bjoern C; Beveridge, Ian

2014-12-19

Borneo is considered a centre for biodiversity in both the terrestrial and aquatic environments. However, information on the diversity of parasites and trypanorhynch cestodes infecting sharks and rays in particular is rather limited at present. During a large-scale study focusing on the parasite diversity of elasmobranchs from Malaysian and Indonesian Borneo a total of 520 spiral intestines of elasmobranchs were collected during seven years of extensive sampling. Trypanorhynch cestodes were discovered in 163 specimens belonging to 43 different elasmobranch species (i.e. 17 species of sharks and 26 species of rays). Overall, 50 species of trypanorhynchs were recovered from the hosts' spiral intestines, some of which represented new species and genera that have been subsequently described. Numerous new host records are added for previously described species. Of the 50 trypanorhynch species present in waters off Borneo 30 (= 60%) were recovered from rays, while 20 species (= 40%) were found in sharks. The geographical distribution of these cestode species was dominated by taxa that occur in the Indo-west Pacific (= 30%) followed by species endemic to Borneo (= 28%). Nine species (= 18%) are found both in Borneo and Australia or have a cosmopolitan distribution. The present study also assessed the host specificity for 16 species belonging to three prominent trypanorhynch genera recovered from elasmobranchs from Borneo (i.e. Dollfusiella Campbell & Beveridge, 1994, Prochristianella Dollfus, 1946 and Parachristianella Dollfus, 1946). Most species (= 63%) were euryxenous utilizing hosts from different orders or even classes, with only a single species (i.e. Dollfusiella imparispinis Schaeffner & Beveridge, 2013) being oioxenous utilizing a single host species. The remaining species (= 31%) were mesostenoxenous utilizing different host species from a single genus. The least host specific taxa were the three representatives of Parachristianella and Prochristianella clarkeae Beveridge, 1990.

Diphyllidean cestodes of the Gulf of California, México with descriptions of two new species of Echinobothrium (Cestoda: Diphyllidea).

PubMed

Tyler, G A

2001-02-01

As part of a survey of parasites of elasmobranchs in the Gulf of California, a second and final report of the diphyllidean cestodes resulting from the survey is presented. Of 43 species of elasmobranchs examined for parasites, 7 (Rhinobatos productus, Rhinobatos leucorhynchus, Myliobatis californicus, Myliobatis longirostris, Urobatis halleri, Urobatis maculatus, and Rhinoptera steindachneri) were found to host diphyllidean cestodes, all belonging to Echinobothrium. No species of either of the other 2 diphyllidean genera, Dirrachybothridium or Macrobothridium, were discovered. A greater diversity of diphyllideans was found in 1996 than in 1993. Two new species, Echinobothrium hoffmanorum n. sp. and Echinobothrium rayallemangi n. sp. are described from the spiral intestines of U. maculatus and R. leucorhynchus, respectively. Echinobothrium hoffmanorum is unique in its possession of the following combination of characters: 19-21 apical hooks in each dorsoventral group, 12-22 lateral hooklets in each group, 10-17 cephalic peduncle spines per column, 4-8 testes, 4-10 segments and eggs with a single filament. Echinobothrium rayallemangi is unique in its possession of the following combination of characters: 23 apical hooks in each dorsoventral group, 20-23 lateral hooklets in each group, 2-5 cephalic peduncle spines per column, 4-6 testes, and 4-6 segments. These 2 new species, together with Echinobothrium mexicanum and Echinobothrium fautleyae, brings the total number of diphyllideans known from the Gulf of California to 4. The survey of diphyllidean cestodes of the Gulf of California has resulted in a new host record for Echinobothrium for each of the host species mentioned above, with Rhinobatos and Urobatis representing new host genera and Urolophidae a new host family for Echinobothrium.

Detailed transcriptome description of the neglected cestode Taenia multiceps.

PubMed

Wu, Xuhang; Fu, Yan; Yang, Deying; Zhang, Runhui; Zheng, Wanpeng; Nie, Huaming; Xie, Yue; Yan, Ning; Hao, Guiying; Gu, Xiaobin; Wang, Shuxian; Peng, Xuerong; Yang, Guangyou

2012-01-01

The larval stage of Taenia multiceps, a global cestode, encysts in the central nervous system (CNS) of sheep and other livestock. This frequently leads to their death and huge socioeconomic losses, especially in developing countries. This parasite can also cause zoonotic infections in humans, but has been largely neglected due to a lack of diagnostic techniques and studies. Recent developments in next-generation sequencing provide an opportunity to explore the transcriptome of T. multiceps. We obtained a total of 31,282 unigenes (mean length 920 bp) using Illumina paired-end sequencing technology and a new Trinity de novo assembler without a referenced genome. Individual transcription molecules were determined by sequence-based annotations and/or domain-based annotations against public databases (Nr, UniprotKB/Swiss-Prot, COG, KEGG, UniProtKB/TrEMBL, InterPro and Pfam). We identified 26,110 (83.47%) unigenes and inferred 20,896 (66.8%) coding sequences (CDS). Further comparative transcripts analysis with other cestodes (Taenia pisiformis, Taenia solium, Echincoccus granulosus and Echincoccus multilocularis) and intestinal parasites (Trichinella spiralis, Ancylostoma caninum and Ascaris suum) showed that 5,100 common genes were shared among three Taenia tapeworms, 261 conserved genes were detected among five Taeniidae cestodes, and 109 common genes were found in four zoonotic intestinal parasites. Some of the common genes were genes required for parasite survival, involved in parasite-host interactions. In addition, we amplified two full-length CDS of unigenes from the common genes using RT-PCR. This study provides an extensive transcriptome of the adult stage of T. multiceps, and demonstrates that comparative transcriptomic investigations deserve to be further studied. This transcriptome dataset forms a substantial public information platform to achieve a fundamental understanding of the biology of T. multiceps, and helps in the identification of drug targets and parasite-host interaction studies.

Parasitic helminths in the digestive tract of six species of owls (Strigiformes) in Spain.

PubMed

Ferrer, David; Molina, Rafael; Castellà, Joaquim; Kinsella, John M

2004-03-01

A survey was carried out in Catalonia, Spain to determine the prevalence of parasitic helminths infesting the digestive tract of nocturnal raptors (Strigiformes). One hundred birds belonging to six owl species were examined. The number of birds examined ranged between three and 30. The overall level of infestation was 65% and the most frequent helminths present were nematodes, followed by trematodes, cestodes and acanthocephalans. Strigiformes showing the highest levels of infestation were little owls (Athene noctua), 86.7% of which were infested. Helminths with the highest prevalence were Synhimantus spp., intestinal capillarids, Brachylaima spp., cestodes and Centrorhynchus aluconis.

Endohelminth parasites of the leafscale gulper shark, Centrophorus squamosus (Bonnaterre, 1788) (Squaliformes:Centrophoridae) off Madeira Archipelago.

PubMed

Costa, Graça; Chada, Tomás; Melo-Moreira, Egberto; Cavallero, Serena; D'Amelio, Stefano

2014-06-01

The endohelminth parasite fauna of a deep water shark, the leafscale gulper shark, Centrophorus squamosus, examined from Madeiran waters, from September 2009 to January 2010, consisted of larval and juvenile cestodes of two orders, namely Trypanorhyncha and Tetraphyllidea, and L3 stages of Anisakis spp. Infection with Anisakis spp. could be due to the shark's opportunistic feeding on squids and black-scabbard fish, Aphanopus carbo, which is heavily parasitized by Anisakis spp. in Madeira waters. The occurrence of larval and juvenile cestodes only, in this shark, suggests that the leafscale gulper shark features as a paratenic or a dead-end host for the parasites.

The impact of globalisation on the distribution of Echinococcus multilocularis.

PubMed

Davidson, Rebecca K; Romig, Thomas; Jenkins, Emily; Tryland, Morten; Robertson, Lucy J

2012-06-01

In the past three decades, Echinococcus multilocularis, the cause of human alveolar echinococcosis, has been reported in several new countries both in definitive hosts (canids) as well as in people. Unless treated, infection with this cestode in people is fatal. In previously endemic countries throughout the Northern Hemisphere, geographic ranges and human and animal prevalence levels seem to be increasing. Anthropogenic influences, including increased globalisation of animals and animal products, and altered human/animal interfaces are thought to play a vital role in the global emergence of this pathogenic cestode. Molecular epidemiological techniques are a useful tool for detecting and tracing introductions, and differentiating these from range expansions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Parasitation of sea trout (Salmo trutta trutta L.) from the spawning ground and German coastal waters off Mecklenburg-Western Pomerania, Baltic Sea.

PubMed

Unger, Patrick; Palm, Harry W

2016-01-01

A total of 52 sea trouts, Salmo trutta trutta, were studied for parasites, originating from German freshwater streams and coastal waters of the Baltic Sea. While 35 specimens were caught mainly close to the shoreline in the Baltic Sea, 17 were sampled during their spawning migration in Warnow River and other neighboring rivers in Mecklenburg-Western Pomerania. A total of 12 different metazoan parasite species were found in sea trout originating from the Baltic Sea, including five digeneans, two cestodes, three nematodes, and two acanthocephalans. Marine and freshwater species were found. In the migratory trout, seven different parasite species were recorded (one digenean, two cestodes, one nematode, and one acanthocephalan), demonstrating lower parasite diversity and load during the spawning migration compared with the fish from the Baltic Sea. The anisakid nematodes Anisakis simplex (sensu stricto), Contraceacum rudolphii, and Hysterothylacium aduncum were identified by molecular analyses of the ITS-1, 5.8S, ITS-2, and flanking sequences of the rDNA. Together with the digenean Derogenes varicus, Hemiurus communis and H. luehei, and the cestode Diphyllobothrium dendriticum seven new host records for sea trout from the German part of the Baltic Sea are made.

Tegument galactosylceramides of the cestode Spirometra mansonoides.

PubMed

Singh, B N; Costello, C E; Levery, S B; Walenga, R W; Beach, D H; Mueller, J F; Holz, G G

1987-11-01

The brush border-like surface of the tegument of the adult and the plerocercoid larva of a pseudophyllidean cestode, Spirometra mansonoides, has been shown to contain hydroxylated galactosylceramides. D-Galactosyl-N-(2-D-hydroxyoctadecanoyl)-D-phytosphingosine, D-galactosyl-N-(2-D-hydroxyoctadecanoyl)-D-dihydrosphingosine and D-galactosyl-N-(octadecanoyl)-D-phytosphingosine were identified as major glycosphingolipids in a tegumental plasma membrane fraction with associated microtriches, by combinations of chromatography (column, high performance thin-layer, gas-liquid), mass spectrometry (electron impact, field desorption, fast atom bombardment, collisionally induced decomposition) and proton nuclear magnetic resonance spectrometry. Galactosylceramides with hydroxylated long chain bases and fatty acids are known to occur in some eukaryotic microbes and in cells of vertebrate tissues exposed to plasma membrane destabilizing environments. This has led to a proposal that the capacity of hydroxylated ceramide moieties for intermolecular hydrogen bonding among themselves and with phosphoglycerides acts to stabilize the plasma membrane. Saturated fatty acyl groups in the ceramides would enhance stabilization by their orderly packing in the lipid bilayer. Consequently, the presence of such hydroxylated galactosylceramides in the tegument surface of S. mansonoides may contribute to the maintenance of its normal barrier properties in the face of the varied environmental insults encountered by the cestode in its life-cycle.

Evolutionary characterization of Ty3/gypsy-like LTR retrotransposons in the parasitic cestode Echinococcus granulosus.

PubMed

Bae, Young-An

2016-11-01

Cyclophyllidean cestodes including Echinococcus granulosus have a smaller genome and show characteristics such as loss of the gut, a segmented body plan, and accelerated growth rate in hosts compared with other tissue-invading helminths. In an effort to address the molecular mechanism relevant to genome shrinkage, the evolutionary status of long-terminal-repeat (LTR) retrotransposons, which are known as the most potent genomic modulators, was investigated in the E. granulosus draft genome. A majority of the E. granulosus LTR retrotransposons were classified into a novel characteristic clade, named Saci-2, of the Ty3/gypsy family, while the remaining elements belonged to the CsRn1 clade of identical family. Their nucleotide sequences were heavily corrupted by frequent base substitutions and segmental losses. The ceased mobile activity of the major retrotransposons and the following intrinsic DNA loss in their inactive progenies might have contributed to decrease in genome size. Apart from the degenerate copies, a gag gene originating from a CsRn1-like element exhibited substantial evidences suggesting its domestication including a preserved coding profile and transcriptional activity, the presence of syntenic orthologues in cestodes, and selective pressure acting on the gene. To my knowledge, the endogenized gag gene is reported for the first time in invertebrates, though its biological function remains elusive.

Intestinal parasites of the Arctic fox in relation to the abundance and distribution of intermediate hosts.

PubMed

Stien, A; Voutilainen, L; Haukisalmi, V; Fuglei, E; Mørk, T; Yoccoz, N G; Ims, R A; Henttonen, H

2010-01-01

The intestinal parasite community of Arctic foxes (Vulpes lagopus) on the Svalbard archipelago in the High Arctic was investigated in relation to the abundance and distribution of intermediate hosts. Five species of cestodes (Echinococcus multilocularis, Taenia crassiceps, Taenia polyacantha, Taenia krabbei and Diphyllobothrium sp.), ascaridoid nematodes and one unidentified acanthocephalan species were found. The cestodes E. multilocularis, T. crassiceps and T. polyacantha all showed a decreasing prevalence in the fox population with increasing distance from their spatially restricted intermediate host population of sibling voles (Microtus levis). In addition, the prevalence of E. multilocularis in a sample from the vole population was directly related to the local vole abundance. The cestode T. krabbei uses reindeer as intermediate host, and its prevalence in female foxes was positively related to the density of reindeer (Rangifer tarandus platyrhyncus). Finally, the prevalence of the ascaridoid nematodes also decreased with increasing distance from the vole population, a finding that is consistent with the idea that voles are involved in transmission, most likely as paratenic hosts. The prevalence of the remaining species (Diphyllobothrium sp. and an unidentified acanthocephalan) was very low. We conclude that the distribution and abundance of intermediate host structure the gastrointestinal parasite community of the Arctic fox on the Svalbard archipelago.

A new genus and species of proteocephalidean tapeworm (Cestoda) from Pangasius larnaudii (Siluriformes: Pangasiidae) in Southeast Asia.

PubMed

Scholz, Tomáš; de Chambrier, Alain

2012-06-01

A new proteocephalidean cestode is described from spot pangasius, Pangasius larnaudii (Siluriformes: Pangasiidae), from Tonle Sap Lake in Cambodia and a new genus, Pangasiocestus , is proposed to accommodate it. The genus is placed in the Gangesiinae because its scolex possesses a large rostellum-like apical organ and its genital organs (testes, ovary, vitellarium, and uterus) are situated in the medulla, with some vitelline follicles paramuscular. Pangasiocestus romani n. gen. and n. sp., the type and only species of the new genus, is characterized mainly by its rosette-like scolex composed of 4 lobes bearing a small sucker in their center, and the apical part with a large, discoidal, rostellum-like apical organ devoid of hooks, by weakly developed inner longitudinal musculature formed by very few isolated muscle fibers, uneven size of testes in immature and mature proglottids, with lateral testes smaller and more dense than median ones, by very narrow lateral bands of vitelline follicles, formed usually by single follicles, and by the vagina anterior to the cirrus sac. This is the first proteocephalidean cestode from a pangasiid catfish identified to the species level (proteocephalidean cestodes from 3 Pangasius spp. reported in an unpublished account from Vietnam, misidentified as Proteocephalus osculatus (Goeze, 1782) [ =  Glanitaenia osculata ], are not considered).

The occurrence of the larval cestode Cysticercus fasciolaris in rodent populations from the Cuxtal ecological reserve, Yucatan, Mexico.

PubMed

Rodríguez-Vivas, R I; Panti-May, J A; Parada-López, J; Hernández-Betancourt, S F; Ruiz-Piña, H A

2011-12-01

Cysticercus fasciolaris is the larval stage of the cestode Taenia taeniaeformis, whose definitive hosts are mainly cats. This larval stage uses a wide variety of small rodents, and occasionally birds and humans, as intermediate hosts. In the Yucatan, there are no reports of the presence of this cestode in animal populations. The aim of this study was to evaluate the occurrence of C. fasciolaris in rodent populations from the Cuxtal ecological reserve, Yucatan, Mexico. Trapping of rodents was conducted from October 2009 to April 2010 in 40 households in Molas, in which Sherman traps were placed both inside and outside backyards. Rodents were dissected to inspect the liver for the presence of the worm. To determine risk factors associated with infection, univariate analysis was performed using sex, age, species, trapping site, and season as independent variables. Variables with a P value <  0.2 were analysed using a logistic regression model. In this study, 411 individuals of six rodent species were trapped; Mus musculus was the most abundant (78%), followed by Rattus rattus (13%) and the wild species Peromyscus yucatanicus, Ototylomys phyllotis, Heteromys gaumeri and Reithrodontomys gracilis (9%). Only 7.5% (n = 31) of M. musculus and R. rattus were infected with C. fasciolaris (demonstrated by the presence of liver cysts) with a prevalence of 9.0% and 3.5%, respectively. Both adults and male mice were 4.33 and 3.46 (OR values) times more likely to have C. fasciolaris than juveniles and females respectively. We can conclude that in the Cuxtal Reserve, Yucatan, Mexico, the prevalence of C. fasciolaris is higher in M. musculus, and that adult males had a higher probability of infection. Wild species, mainly P. yucatanicus, were not found to be infected with the cestode, but its presence in the backyards of households could result in a potential risk of acquiring this infection.

Detailed Transcriptome Description of the Neglected Cestode Taenia multiceps

PubMed Central

Wu, Xuhang; Fu, Yan; Yang, Deying; Zhang, Runhui; Zheng, Wanpeng; Nie, Huaming; Xie, Yue; Yan, Ning; Hao, Guiying; Gu, Xiaobin; Wang, Shuxian; Peng, Xuerong; Yang, Guangyou

2012-01-01

Background The larval stage of Taenia multiceps, a global cestode, encysts in the central nervous system (CNS) of sheep and other livestock. This frequently leads to their death and huge socioeconomic losses, especially in developing countries. This parasite can also cause zoonotic infections in humans, but has been largely neglected due to a lack of diagnostic techniques and studies. Recent developments in next-generation sequencing provide an opportunity to explore the transcriptome of T. multiceps. Methodology/Principal Findings We obtained a total of 31,282 unigenes (mean length 920 bp) using Illumina paired-end sequencing technology and a new Trinity de novo assembler without a referenced genome. Individual transcription molecules were determined by sequence-based annotations and/or domain-based annotations against public databases (Nr, UniprotKB/Swiss-Prot, COG, KEGG, UniProtKB/TrEMBL, InterPro and Pfam). We identified 26,110 (83.47%) unigenes and inferred 20,896 (66.8%) coding sequences (CDS). Further comparative transcripts analysis with other cestodes (Taenia pisiformis, Taenia solium, Echincoccus granulosus and Echincoccus multilocularis) and intestinal parasites (Trichinella spiralis, Ancylostoma caninum and Ascaris suum) showed that 5,100 common genes were shared among three Taenia tapeworms, 261 conserved genes were detected among five Taeniidae cestodes, and 109 common genes were found in four zoonotic intestinal parasites. Some of the common genes were genes required for parasite survival, involved in parasite-host interactions. In addition, we amplified two full-length CDS of unigenes from the common genes using RT-PCR. Conclusions/Significance This study provides an extensive transcriptome of the adult stage of T. multiceps, and demonstrates that comparative transcriptomic investigations deserve to be further studied. This transcriptome dataset forms a substantial public information platform to achieve a fundamental understanding of the biology of T. multiceps, and helps in the identification of drug targets and parasite-host interaction studies. PMID:23049872

Annotation of the Transcriptome from Taenia pisiformis and Its Comparative Analysis with Three Taeniidae Species

PubMed Central

Yang, Deying; Fu, Yan; Wu, Xuhang; Xie, Yue; Nie, Huaming; Chen, Lin; Nong, Xiang; Gu, Xiaobin; Wang, Shuxian; Peng, Xuerong; Yan, Ning; Zhang, Runhui; Zheng, Wanpeng; Yang, Guangyou

2012-01-01

Background Taenia pisiformis is one of the most common intestinal tapeworms and can cause infections in canines. Adult T. pisiformis (canines as definitive hosts) and Cysticercus pisiformis (rabbits as intermediate hosts) cause significant health problems to the host and considerable socio-economic losses as a consequence. No complete genomic data regarding T. pisiformis are currently available in public databases. RNA-seq provides an effective approach to analyze the eukaryotic transcriptome to generate large functional gene datasets that can be used for further studies. Methodology/Principal Findings In this study, 2.67 million sequencing clean reads and 72,957 unigenes were generated using the RNA-seq technique. Based on a sequence similarity search with known proteins, a total of 26,012 unigenes (no redundancy) were identified after quality control procedures via the alignment of four databases. Overall, 15,920 unigenes were mapped to 203 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Through analyzing the glycolysis/gluconeogenesis and axonal guidance pathways, we achieved an in-depth understanding of the biochemistry of T. pisiformis. Here, we selected four unigenes at random and obtained their full-length cDNA clones using RACE PCR. Functional distribution characteristics were gained through comparing four cestode species (72,957 unigenes of T. pisiformis, 30,700 ESTs of T. solium, 1,058 ESTs of Eg+Em [conserved ESTs between Echinococcus granulosus and Echinococcus multilocularis]), with the cluster of orthologous groups (COG) and gene ontology (GO) functional classification systems. Furthermore, the conserved common genes in these four cestode species were obtained and aligned by the KEGG database. Conclusion This study provides an extensive transcriptome dataset obtained from the deep sequencing of T. pisiformis in a non-model whole genome. The identification of conserved genes may provide novel approaches for potential drug targets and vaccinations against cestode infections. Research can now accelerate into the functional genomics, immunity and gene expression profiles of cestode species. PMID:22514598

Pulmonary cestodiasis in a cynomolgus monkey (Macaca fascicularis).

PubMed

Guillot, L M; Green, L C

1992-04-01

Cestodiasis in primates has been noted historically to occur quite frequently, although tissue damage and clinical signs may or may not be apparent. Larval cestodes, such as hydatid cysts or cysticercus cysts, are known to cause extensive tissue damage, while other larval cestodes, such as tetrathyridia, cause minimal damage to the host. This case history concerns an apparently healthy cynomolgus monkey that was part of a surgical study. During the study, all parameters were normal. The monkey died 3 hours postsurgery. The apparent cause of death was respiratory arrest. At necropsy, it was discovered there were 1- to 3-mm-diameter cysts, which on transection extruded 2- to 5-mm-long larvae. The larvae could not be positively identified; however, they resembled tetrathyridia of Mesocestoides sp.

Helminth communities of three sympatric species of shorebirds (Charadrii) from four summer seasons at Bristol Bay, Alaska.

PubMed

Canaris, Albert G; Kinsella, John M

2007-06-01

Helminth communities in sympatric black turnstones (Arenaria melanocephala), ruddy turnstones (Arenaria interpres), and dunlin (Calidris alpina) were examined over 4 summers in Bristol Bay, Alaska. The compound community, made up of component communities of all 3 species of hosts for 4 summer seasons (n=164), consisted of 43 helminth species, with cestodes, especially Anomotaenia clavigera, accounting for 47% of the helminth species and 95% of the abundance. The black turnstone had significantly higher species richness and abundance than either the ruddy turnstone or dunlin. The congeneric black and ruddy turnstone component communities were the most similar, and the dunlin's was the least similar. New helminth species continued to be acquired in all 3 host species during years 2 to 4. There was no significant difference for abundance among sample years for each of the 3 species of host. The 3 component communities all included a predictable suite of helminths with 1 dominant species and 4 to 5 associates, a large number of less-predictable species, and a greater prevalence and abundance of cestode species. Consistencies over time included high diversity, low evenness, low species richness (<5), and continued recruitment of small numbers of helminth species with low prevalence and abundance. There was minimal circulation of helminth species between the dunlin and the 2 turnstone species, indicating a considerable degree of specialization, particularly among species of cestodes.

Taeniasis

MedlinePlus

... Taenia solium; Taeniasis Images Digestive system organs References King CH, Fairley JK. Tapeworms (cestodes). In: Bennett JE, ... commercial use must be authorized in writing by ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer ...

First identification of eggs of the Asian fish tapeworm Bothriocephalus acheilognathi (Cestoda: Bothriocephalidea) in human stool.

PubMed

Yera, Hélène; Kuchta, Roman; Brabec, Jan; Peyron, François; Dupouy-Camet, Jean

2013-06-01

We report the first case of egg isolation of the Asian fish tapeworm Bothriocephalus acheilognathi (Bothriocephalidea) from human stool. A male patient from Saint Laurent du Maroni (French Guiana) presenting abdominal pain was examined in France for the diagnosis of intestinal parasites. Diphyllobothrium-like eggs were observed in his stool. However, molecular phylogenetic analyses based on sequences of rDNA and COI genes showed that the eggs observed belong to a bothriocephalidean cestode B. acheilognathi. The adult life stages of B. acheilognathi cestodes are known as invasive parasites of a wide spectrum of fish; however, they have not been described to parasitize any mammals. This human infection seems to be accidental and represents a parasite passage through human intestine after the consumption of an infected fish host. Copyright © 2013. Published by Elsevier Ireland Ltd.

Helminth parasites of the digestive tract of the oystercatcher, Haematopus ostralegus, in the Wadden Sea, The Netherlands

NASA Astrophysics Data System (ADS)

Borgsteede, F. H. M.; Van den Broek, E.; Swennen, C.

The digestive tracts of 90 oystercatchers (equal numbers of males and females and of juveniles, subadults and adults) wintering in the Dutch Wadden Sea were examined for helminth parasites. The nematodes Capillaria sp. (36.7%) and Streptocara crassicauda (7.8%) were found in the stomach. Unidentified cestodes (76.7%) and the trematodes Psilostomum brevicolle (42.2%), Notocotylus sp. (81.1%), and unidentified gymnophallids (100%) were found in the intestine and caeca. Two birds were infected with Gymnophallidae only, while all other birds contained additional helminth species. Compared with subadult and adult birds, the juveniles had significantly more infections with Capillaria sp. and cestodes. Moreover, the juveniles were infected with a greater variety of species. No further relation was found between the presence of helminths or worm numbers and age groups or sexes of birds.

Survey of protozoan, helminth and viral infections in shrimp Litopenaeus setiferus and prawn Macrobrachium acanthurus native to the Jamapa River region, Mexico.

PubMed

Domínguez-Machín, Magda E; Hernández-Vergara, Martha P; Jiménez-García, Isabel; Simá-Alvarez, Raúl; Rodríguez-Canul, Rossanna

2011-09-09

We surveyed protozoan and metazoan parasites as well as white spot syndrome virus (WSSV) and infectious hypodermal hematopoietic necrosis virus (IHHNV) in white shrimp Litopenaeus setiferus and the palaemonid prawn Macrobrachium acanthurus native to the lower Jamapa River region of Veracruz, Mexico. The presence of parasites and the infection parameters were evaluated in 113 palaemonid prawns collected during the northwind (n = 45), rainy (n = 38) and dry seasons (n = 30) between October 2007 and July 2008, and in 91 shrimp collected in the rainy season between May and June 2008. In L. setiferus, ciliates of the subclass Apostomatia (Ascophrys sp.) were evident in gills, and third-stage larvae of the nematode Physocephalus sexalatus were evident in the stomach. Cestodes of the genus Prochristianella were evident in the hepatopancreas, while some gregarines of the genus Nematopsis, as well as unidentified larval cestodes, were observed in the intestine. Histology identified Ascophrys sp. in association with gill necrosis and tissue melanization. Slight inflammation was observed in intestinal epithelium near cestode larvae. In M. acanthurus, epibionts of the protozoans Epistylis sp., Acineta sp. and Lagenophrys sp. were observed under uropods, periopods and pleopods. An unidentified ciliate of the Apostomatia was also found in the gills, and Nematopsis was identified in the intestine. No histopathology was observed in association with these parasites. Moreover, neither WSSV nor IHHNV were detected by the polymerase chain reaction (PCR) in any of the L. setiferus or M. acanthurus analysed.

Bothriocephalus acheilognathi (Cestoda) in the endangered fish Profundulus hildebrandi (Cyprinodontiformes), Mexico.

PubMed

Velázquez-Velázquez, Ernesto; González-Solís, David; Salgado-Maldonado, Guillermo

2011-09-01

The Asian fish tapeworm, Bothriocephalus acheilognathi, has been considered one of the most dangerous parasites for cultured carp and a risk for native freshwater fish populations worldwide. This cestode is highly pathogenic for fishes especially fry. In this paper we record B. acheilognathi parasitizing the endangered and endemic freshwater fish Profundulus hildebrandi from the endorheic basin of San Crist6bal de las Casas, Chiapas, Mexico. B. acheilognathi was recorded from 10 of the 11 sampled localities, with high values of prevalence (> 60%) and mean abundance (> 4.50). The infection was persistent all through the year; gravid cestodes were recorded in all samples. It is assumed that B. acheilognathi entered to this area through the introduction of common carp Cyprinus carpio, for aquacultural purposes. The data presented in this paper document the successful introduction, colonization and establishment of this alien species into the endangered P. hildebrandi.

High-throughput identification of miRNAs of Taenia ovis, a cestode threatening sheep industry.

PubMed

Zheng, Yadong

2017-07-01

Taenia ovis is a tapeworm that is mainly transmitted between dogs and sheep or goats and has an adverse effect on sheep industry. miRNAs are short regulatory non-coding RNAs, involved in parasite development and growth as well as parasite infection. The miRNA profile of T. ovis remains to be established. Herein, 33 known miRNAs belonging to 23 different families were identified in T. ovis metacestodes using deep sequencing approach. Of them, expression of some miRNAs such as tov-miR-10 and -let-7 was absolutely predominant. Moreover, comparative analysis revealed the presence of a miR-71/2b/2c cluster in T. ovis, which was also completely conserved in other 6 cestodes. The study provides rich data for further understandings of T. ovis biology. Copyright © 2017 Elsevier B.V. All rights reserved.

First record of the invasive Asian fish tapeworm Bothriocephalus acheilognathi in Honduras, Central America

PubMed Central

Salgado-Maldonado, Guillermo; Matamoros, Wilfredo A.; Kreiser, Brian R.; Caspeta-Mandujano, Juan Manuel; Mendoza-Franco, Edgar F.

2015-01-01

This paper provides the first report of the invasive Asian fish tapeworm, Bothriocephalus acheilognathi Yamaguti, 1934, in Honduras. The cestode was found in Profundulus portillorum (Cyprinodontiformes: Profundulidae), which represents a new host record, and which is a member of a genus faced with a variety of conservation challenges, now potentially complicated by the presence of this pathogenic cestode. Nearly complete sequence data from the ITS-1 5.8S and ITS-2 regions corroborate the determination based on morphological characteristics. Several species of carp were introduced to Honduras for aquaculture purposes in the early 1980s and the presence of the Asian fish tapeworm in Honduras may be related to these introductions. In addition, this report documents the currently known geographical distribution of this parasite in Central America, first recorded from Panamá and now from Honduras. PMID:25654444

First record of the invasive Asian fish tapeworm Bothriocephalus acheilognathi in Honduras, Central America.

PubMed

Salgado-Maldonado, Guillermo; Matamoros, Wilfredo A; Kreiser, Brian R; Caspeta-Mandujano, Juan Manuel; Mendoza-Franco, Edgar F

2015-01-01

This paper provides the first report of the invasive Asian fish tapeworm, Bothriocephalus acheilognathi Yamaguti, 1934, in Honduras. The cestode was found in Profundulus portillorum (Cyprinodontiformes: Profundulidae), which represents a new host record, and which is a member of a genus faced with a variety of conservation challenges, now potentially complicated by the presence of this pathogenic cestode. Nearly complete sequence data from the ITS-1 5.8S and ITS-2 regions corroborate the determination based on morphological characteristics. Several species of carp were introduced to Honduras for aquaculture purposes in the early 1980s and the presence of the Asian fish tapeworm in Honduras may be related to these introductions. In addition, this report documents the currently known geographical distribution of this parasite in Central America, first recorded from Panamá and now from Honduras. © G. Salgado-Maldonado et al., published by EDP Sciences, 2015.

Sperm transfer in monogenean (platyhelminth) parasites.

PubMed

Kearn, Graham; Whittington, Ian

2015-12-01

There are three major groups of parasitic platyhelminths (flatworms). The digeneans and cestodes are endoparasites, while the monogeneans are ectoparasites mostly on the gills or skin of fishes. Monogeneans are hermaphrodite and, with the exception of the gyrodactylids, mostly protandrous, the male reproductive system maturing before the female system. Their ectoparasitic life-style provides unique opportunities to observe the reproductive biology of living platyhelminths, opportunities restricted in digeneans and cestodes by their endoparasitic habits. Moreover, the male copulatory organs (MCOs) of monogeneans are of special interest because of their perplexing diversity, ranging from sclerotised penis tubes, many with accessory sclerites, to cirruses and genital atrium armature (hooks and spines). The relatively few accounts in the literature of mating in monogeneans are reproduced in this review, together with consideration of the following aspects of sperm transfer: structure and function of MCOs; self-insemination; spermatophores and pseudospermatophores; "hypodermic" and transtegumental insemination; tissue fusion; glands associated with MCOs and vaginae; finding a mating partner.

Validation of internal controls for gene expression analysis in the intestine of rats infected with Hymenolepis diminuta.

PubMed

Hoque, Tafazzal; Bhogal, Meetu; Boghal, Meetu; Webb, Rodney A

2007-12-01

The non-invasive parasitic cestode Hymenolepis diminuta induces hypertrophy, hyperplasia and other changes in cell activity in the intestine of rats which are indicated in the expression of mRNA. We have investigated various house-keeping genes (GAPDH, beta-actin, 18S and HPRT) and other internal controls (total RNA/unit biomass, total RNA/unit length of intestine) to validate gene expression in the rat intestine after cestode infection and drug-induced neuromodulation. Variation in GAPDH, beta-actin, 18S and HPRT expression was observed in rat jejunal tissue according to treatment. Total RNA/unit length of intestine was found to be the most suitable internal control for normalizing target gene mRNA expression in both infected and/or drug-induced rat intestine. This normalization method may be applied to studies of gene expression levels in intestinal tissue where hypertrophy, hyperplasia, rapid growth and cell differentiation generally occur.

[Helminthic fauna of commercial fishes from the Saya-de-Malya bank (Indian Ocean)].

PubMed

Parukhin, A M

1988-01-01

The data on infestation of 8 species of commercial fishes from Saya-de-Malya bank (the Indian Ocean) are presented. 43 helminth species were identified: 10 Monogenea species, 18 trematode, 7 cestode and 8 nematode species. The mature worms are observed to be related to a certain host, whereas the nematode and cestode larvae have wide specificity. High infestation degree by Anisakis larvae is found in fishes, especially in Carangidae. At the bank area fishes are found to be free from Acanthocephala while those Acanthocephala are found in fishes from other areas of the Indian Ocean which may be attributed to the specific diet at the Saya-de-Malya bank. On the whole the helminth fauna of fishes examined at the Saya-de-Malya bank does not demonstrate the endemic pattern. The most specific helminth species were found in some fish species.

Immunity to adult cestodes: basic knowledge and vaccination problems. A review.

PubMed

Andreassen, J

1991-04-01

Immunity in mammals to intestinal cestodes has been reviewed using the normal final host infected with the tapeworms Hymenolepis diminuta in rats and H. microstoma and H. nana in mice as a model. Primary infections up to a certain level continue to live as long the host, while most worms in infections with larger doses are destrobilated and expelled. It has been argued that concomitant immunity against a superimposed infection exists in rats and mice infected with H. diminuta and H. microstoma, respectively, and suggested that it also takes place in humans infected with Taenia spp. Immunity to secondary infections after expulsion of a primary infection occurs, but immunological memory is rather short-lived, although depression of worm growth occurs for at least two third of the rat's life. Serum antibodies have been shown to produce a direct precipitate on the surface of cestodes in vitro, but a direct effect of antibodies in vivo or the relationship with e.g. host effector cells, like mast cells and eosinophils, is unknown. It has been shown that peritoneal exudate cells from rats are able to kill H. diminuta in vitro. Very little is known about the mechanisms of tapeworms to counteract host immunological responses, but the tegumental glycoconjugates and discoidal secretory bodies are possible candidates. Passive transfer of immunity by mesenteric lymph node cells has only been successful using cells from H. nana egg-infected mice and has shown that only short-lived proliferating cells are responsible for transferring immunity. Vaccination procedures and problems are discussed with special reference to E. granulosus in dogs.

Alternative prey use affects helminth parasite infections in grey wolves.

PubMed

Friesen, Olwyn C; Roth, James D

2016-09-01

Predators affect prey populations not only through direct predation, but also by acting as definitive hosts for their parasites and completing parasite life cycles. Understanding the affects of parasitism on prey population dynamics requires knowing how their predators' parasite community is affected by diet and prey availability. Ungulates, such as moose (Alces americanus) and white-tailed deer (Odocoileus virginianus), are often important prey for wolves (Canis lupus), but wolves also consume a variety of alternative prey, including beaver (Castor canadensis) and snowshoe hare (Lepus americanus). The use of alternative prey, which may host different or fewer parasites than ungulates, could potentially reduce overall abundance of ungulate parasites within the ecosystem, benefiting both wolves and ungulate hosts. We examined parasites in wolf carcasses from eastern Manitoba and estimated wolf diet using stable isotope analysis. Taeniidae cestodes were present in most wolves (75%), reflecting a diet primarily comprised of ungulates, but nematodes were unexpectedly rare. Cestode abundance was negatively related to the wolf's δ(13) C value, indicating diet affects parasite abundance. Wolves that consumed a higher proportion of beaver and caribou (Rangifer tarandus), estimated using Bayesian mixing models, had lower cestode abundance, suggesting the use of these alternative prey can reduce parasite loads. Long-term consumption of beavers may lower the abundance of adult parasites in wolves, eventually lowering parasite density in the region and ultimately benefiting ungulates that serve as intermediate hosts. Thus, alternative prey can affect both predator-prey and host-parasite interactions and potentially affect food web dynamics. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Fine structure of uterus and non-functioning paruterine organ in Orthoskrjabinia junlanae (Cestoda, Cyclophyllidea).

PubMed

Korneva, Janetta V; Kornienko, Svetlana A; Jones, Malcolm K

2016-06-01

Some cyclophyllidean cestodes provide protection for their eggs in the external environment by providing them with additional protective layers around the egg membranes. In attempting to examine such adaptations, the microanatomy and fine structure of the uterus of pregravid and gravid proglottids of the cyclophyllidean cestode Orthoskrjabinia junlanae, a parasite of mammals that inhabit a terrestrial but moist environment, were studied. In the initial stages of uterine development, developing embryos locate freely in the lumen of a saccate uterus that later partitions into chambers. Each chamber that forms encloses several embryos. The chambers are surrounded by muscle cells that synthesize extracellular matrix actively. The paruterine organs consist of stacks of flattened long outgrowths of muscular cells, interspersed with small lipid droplets. In the gravid proglottids, the size of paruterine organ increases and consists of flattened basal and small rounded apical parts separated by constrictions. The fine structure of the organ wall remains the same: sparse nuclei and stacks of flattened cytoplasmic outgrowths but internal invaginations or lumen in the paruterine organ are absent. Completely developed eggs remain localized in the uterus. Based on the comparative morpho-functional analysis of uterine and paruterine organs and uterine capsules in cestodes, we conclude that these non-functioning paruterine organ in O. junlanae is an example of an atavism. We postulate that the life cycle of the parasite, which infects mammals living in wet habitats, where threats of desiccation of parasite ova is reduced, has favoured a reversion to a more ancestral form of uterine development.

Use of a molecular approach for the definitive diagnosis of proliferative larval mesocestoidiasis in a cat.

PubMed

Jabbar, Abdul; Papini, Roberto; Ferrini, Nadia; Gasser, Robin B

2012-10-01

A 9 year-old male, neutered cat with a history of a sudden onset of lethargy, anorexia and respiratory distress was presented in a veterinary practice in Lucca, Italy. A clinical examination revealed that the cat was severely dehydrated, and had pale mucous membranes and tachypnoea. No pain or discomfort was detected at the time of physical examination. The cat was administered fluids, antibiotics and supportive therapy, but died overnight. The owner of the cat requested for a post mortem examination to be conducted. At necropsy, acephalic structures, consistent with proliferative tapeworm (cestode) larvae, were detected in the thoracic cavity on pleural surfaces. As these larvae could not be identified to genus or species by microscopy, a PCR-based sequencing-phylogenetic approach was used. Part of the cytochrome c oxidase subunit 1 gene was PCR-amplified from genomic DNAs from five individual larvae and sequenced; all five sequences obtained were identical. This consensus sequence was aligned (over 355 nucleotide positions) with homologous sequences representing a range of cestodes (including Echinococcus granulosus, Echinococcus multilocularis, Hymenolepis microstoma, Mesocestoides spp. and Taenia saginata) from previously published studies and then subjected to phylogenetic analysis. The sequence representing the larval cestode from the affected cat grouped, with strong statistical support, with those representing Mesocestoides corti and Mesocestoides lineatus. Therefore, a definitive diagnosis of pleural proliferative larval mesocestoidiasis could be made. This study illustrates the value of using molecular tools to directly assist clinical and pathological investigations of cestodiases of animals. Copyright © 2012 Elsevier B.V. All rights reserved.

Orders out of chaos – molecular phylogenetics reveals the complexity of shark and stingray tapeworm relationships

PubMed Central

Caira, Janine N.; Jensen, Kirsten; Waeschenbach, Andrea; Olson, Peter D.; Littlewood, D. Timothy J.

2014-01-01

Novel molecular data are presented to resolve the long-standing issue of the non-monophyly of the elasmobranch-hosted tapeworm order Tetraphyllidea relative to the other acetabulate eucestode orders. Bayesian Inference analyses of various combinations of full ssrDNA, and full or partial lsrDNA (D1-D3), sequence data, which included 134 species representing 97 genera across the 15 eucestode orders, were conducted. New ssrDNA data were generated for 82 species, partial lsrDNA data for 53 species, and full lsrDNA data for 29 species. The monophyly of each of the elasmobranch-hosted orders Cathetocephalidea, Litobothriidea, Lecanicephalidea, and Rhinebothriidea was confirmed, as was the non-monophyly of the Tetraphyllidea. Two relatively stable groups of tetraphyllidean taxa emerged and are hereby designated as new orders. The Onchoproteocephalidea n. ord. is established to recognize the integrated nature of one undescribed and ten described genera of hook-bearing tetraphyllideans, previously of the family Onchobothriidae, with the members of the order Proteocephalidea. The Phyllobothriidea n. ord. is established for a subset of 12 non-hooked genera characterized by scoleces bearing four bothridia each with an anterior accessory sucker; most parasitise sharks and have been assigned to the Phyllobothriidae at one time or another. Tentative ordinal placements are suggested for 8 additional genera; placements for the remaining tetraphyllidean genera have not yet emerged. We propose these 17 genera remain in the “Tetraphyllidea”. Among these, particularly labile across analyses were Anthobothrium, Megalonchos, Carpobothrium, Calliobothrium, and Caulobothrium. The unique association of Chimaerocestus with holocephalans, rather than with elasmobranchs, appears to represent a host-switching event. Both of the non-elasmobranch hosted clades of acetabulate cestodes (i.e., Proteocephalidea and Cyclophyllidea and their kin) appear to have had their origins with elasmobranch cestodes. Across analyses, the sister group to the clade of “terrestrial” cestode orders was found to be an elasmobranch-hosted genus; as was the sister to the freshwater fish and tetrapod-hosted Proteocephalidea. Whilst further data are required to resolve outstanding nomenclatural and phylogenetic issues, the present analyses contribute significantly to an understanding of the evolutionary radiation of the entire Cestoda. Clearly, elasmobranch tapeworms comprise the backbone of cestode phylogeny. PMID:24275646

Orders out of chaos--molecular phylogenetics reveals the complexity of shark and stingray tapeworm relationships.

PubMed

Caira, Janine N; Jensen, Kirsten; Waeschenbach, Andrea; Olson, Peter D; Littlewood, D Timothy J

2014-01-01

Novel molecular data are presented to resolve the long-standing issue of the non-monophyly of the elasmobranch-hosted tapeworm order Tetraphyllidea relative to the other acetabulate eucestode orders. Bayesian inference analyses of various combinations of full ssrDNA, and full or partial lsrDNA (D1-D3), sequence data, which included 134 species representing 97 genera across the 15 eucestode orders, were conducted. New ssrDNA data were generated for 82 species, partial lsrDNA data for 53 species, and full lsrDNA data for 29 species. The monophyly of each of the elasmobranch-hosted orders Cathetocephalidea, Litobothriidea, Lecanicephalidea and Rhinebothriidea was confirmed, as was the non-monophyly of the Tetraphyllidea. Two relatively stable groups of tetraphyllidean taxa emerged and are hereby designated as new orders. The Onchoproteocephalidea n. ord. is established to recognise the integrated nature of one undescribed and 10 described genera of hook-bearing tetraphyllideans, previously placed in the family Onchobothriidae, with the members of the order Proteocephalidea. The Phyllobothriidea n. ord. is established for a subset of 12 non-hooked genera characterised by scoleces bearing four bothridia each with an anterior accessory sucker; most parasitise sharks and have been assigned to the Phyllobothriidae at one time or another. Tentative ordinal placements are suggested for eight additional genera; placements for the remaining tetraphyllidean genera have not yet emerged. We propose that these 17 genera remain in the "Tetraphyllidea". Among these, particularly labile across analyses were Anthobothrium, Megalonchos, Carpobothrium, Calliobothrium and Caulobothrium. The unique association of Chimaerocestus with holocephalans, rather than with elasmobranchs, appears to represent a host-switching event. Both of the non-elasmobranch hosted clades of acetabulate cestodes (i.e. Proteocephalidea and Cyclophyllidea and their kin) appear to have had their origins with elasmobranch cestodes. Across analyses, the sister group to the clade of "terrestrial" cestode orders was found to be an elasmobranch-hosted genus, as was the sister to the freshwater fish- and tetrapod-hosted Proteocephalidea. Whilst further data are required to resolve outstanding nomenclatural and phylogenetic issues, the present analyses contribute significantly to an understanding of the evolutionary radiation of the entire Cestoda. Clearly, elasmobranch tapeworms comprise the backbone of cestode phylogeny. Copyright © 2013 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

[Ultrastructure of nephridial systems in cyclophyllidean cestoda: Catenotaenia pusilla (Goeze, 1782), Hymenolepis diminuta (Rudolphi, 1819) and Inermicapsifer madagascariensis (Davaine, 1870) Baer, 1956].

PubMed

Swiderski, Z; Euzet, L; Schönenberger, N

1975-01-01

Electron microscopic study of nephridial systems in three cyclophyllidean cestodes indicates a resemblance in their ultrastructure. The walls of longitudinal, transverse and collecting ducts show a very similar pattern of organization. The surface of the anucleate epithelium lining the ducts is developed into microvilli. A relatively thick layer of fibrillar tissue underlies the basal membrane of the microvillar epithelium. The nucleated portions or "pericaryons", situated between the parenchymal cells, are directly connected with epithelium by cytoplasmic prolongations. The canalicular lumen extends through a single series of cells curved into a ring. The epithelial surface of the canalicular wall is developed into short, densly staining microvilli and the immediately underlying fibrillar tissue appears very compact. The cilia were never observed in any of the above ducts. The ultrastructure of protonephridia proper is comparable with those already described in other cestodes. There is a close association between the flame-cell and the cancalicular ending, enlarged into a nephridial funnel. A single row of nephridial rods of the flame-cell is surrounded by a row of digitiform prolongations of the nephridial funnel border. The prolongations alternate with the rods and their interlocking pattern appears clearly in cross-sections. A series of minute pores or "nephrostomes" providing a direct contact between the nephridial chamber and intercellular space of the paranchyma was shown. The problem of classification and definition between the "closed" protonephridia and open metanephridia is discussed. The structural unity of protonephridia in different groupes of Platyhelminthes is reviewed. The different number of flagella within the "flames" of different cestodes is compared and analyzed. The ultrastructural characteristics of duct-wall epithelium provides some confirmation of its high metabolic activity.

Plerocercoids of the cestode Diphyllobothrium ditremum in brown trout Salmo trutta: substantial increase in infection after establishment of European minnow Phoxinus phoxinus.

PubMed

Borgstrøm, R; Trømborg, J; Haugen, T O; Rosseland, B O

2017-09-01

This study focuses on plerocercoids of the cestode Diphyllobothrium ditremum in brown trout Salmo trutta from the subalpine lake Øvre Heimdalsvatn in south-central Norway. Salmo trutta was the only fish species in this lake until European minnow Phoxinus phoxinus was registered in 1969. The P. phoxinus population increased substantially in the following years. In contrast with the 1969-1972 period, when plerocercoids of D. ditremum were practically absent in S. trutta, there was a high prevalence and intensity of infection in the 2013 S. trutta samples. Because the life cycle of D. ditremum involves two larval stages, in copepods and salmonids and mature worms in piscivorous birds, such as mergansers and loons, a change in feeding ecology of S. trutta or changes in population densities of copepods, fish or birds might have influenced the infection pattern. No relationships between D. ditremum infection and muscle-tissue δ 15 N signature or Hg concentration were found, indicating that infection is not a result of piscivory or cannibalism. Furthermore, consumption of copepods by S. trutta during summer and autumn was low. On the other hand, the number of piscivorous birds has increased, probably due to the presence of P. phoxinus as a new and numerous prey. An increased number of final D. ditremum hosts may have produced a higher output of cestode eggs, resulting in more infected copepods that in turn are consumed by S. trutta. Indirectly, P. phoxinus may therefore have caused the observed increased infection in S. trutta and thereby imposed further negative effects on S. trutta in high mountain areas. © 2017 The Fisheries Society of the British Isles.

The complete mitochondrial genome of the tapeworm Cladotaenia vulturi (Cestoda: Paruterinidae): gene arrangement and phylogenetic relationships with other cestodes.

PubMed

Guo, Aijiang

2016-08-31

Tapeworms Cladotaenia spp. are among the most important wildlife pathogens in birds of prey. The genus Cladotaenia is placed in the family Paruterinidae based on morphological characteristics and hosts. However, limited molecular information is available for studying the phylogenetic position of this genus in relation to other cestodes. In this study, the complete mitochondrial (mt) genome of Cladotaenia vulturi was amplified using "Long-PCR" and then sequenced by primer walking. Sequence annotation and gene identification were performed by comparison with published flatworm mt genomes. The phylogenetic relationships of C. vulturi with other cestode species were established using the concatenated amino acid sequences of 12 protein-coding genes with Bayesian Inference and Maximum Likelihood methods. The complete mitochondrial genome of the Cladotaenia vulturi is 13,411 kb in size and contains 36 genes. The gene arrangement of C. vulturi is identical to those in Anoplocephala spp. (Anoplocephalidae), Hymenolepis spp. (Hymenolepididae) and Dipylidium caninum (Dipylidiidae), but different from that in taeniids owing to the order shift between the tRNA (L1) and tRNA (S2) genes. Phylogenetic analyses based on the amino acid sequences of the concatenated 12 protein-coding genes showed that the species in the Taeniidae form a group and C. vulturi is a sister taxon to the species of the family Taeniidae. To our knowledge, the present study provides the first molecular data to support the early proposal from morphological evidence that the Taeniidae is a sister group to the family Paruterinidae. This novel mt genome sequence will be useful for further investigations into the population genetics, phylogenetics and systematics of the family Paruterinidae and inferring phylogenetic relationships among several lineages within the order Cyclophyllidea.

Target gene enrichment in the cyclophyllidean cestodes, the most diverse group of tapeworms

USDA-ARS?s Scientific Manuscript database

The Cyclophyllidea is the most diverse order of tapeworms, encompassing species that infect all classes of terrestrial tetrapods including humans and domesticated animals. Available phylogenetic reconstructions based either on morphology or molecular data lack the resolution to allow scientists to ...

Analysis of the peripheral immune response in patients with neurocysticercosis: evidence for T cell reactivity to parasite glycoprotein and vesicular fluid antigens.

PubMed

Restrepo, B I; Aguilar, M I; Melby, P C; Teale, J M

2001-10-01

In neurocysticercosis (NCC), it is thought that the long-term survival of the parasite within the human brain is due in part to the ability of the cestode to suppress the local immune response. When the parasite dies, the immunosuppression is apparently lost and a strong local inflammatory response then develops. In contrast, little is known about the immunologic response that may occur in the peripheral immune system of these patients. In this study, the status of the peripheral (extracerebral) cellular and humoral response was evaluated in patients with a history of NCC. The in vitro proliferation of peripheral blood mononuclear cells to mitogens and foreign antigens was similar in patients and controls. Importantly, a substantive response was elicited by two Taenia solium metacestode antigens. In addition, 8 of 10 patients had a detectable humoral response to the antigenic glycoproteins of the cestode. Considering both the cellular and humoral response, all of the patients with NCC presented an active peripheral immunity.

21 CFR 520.816 - Epsiprantel tablets.

Code of Federal Regulations, 2014 CFR

2014-04-01

... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.816 Epsiprantel tablets. (a... of feline cestodes D. caninum and T. taeniaeformis. (3) Limitations. For oral use only as a single...

21 CFR 520.816 - Epsiprantel tablets.

Code of Federal Regulations, 2012 CFR

2012-04-01

... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.816 Epsiprantel tablets. (a... of feline cestodes D. caninum and T. taeniaeformis. (3) Limitations. For oral use only as a single...

Radiobiological aspects of high altitude flight : relative biological effectiveness of fast neutrons in suppressing immune capacity to an infective agent.

DOT National Transportation Integrated Search

1978-02-01

We investigated the relative biological effectiveness (RBE) of fast neutrons compared with X-rays in impeding development of immunity to an infective agent, the intestinal cestode Hymenolepis nana. Mice were irradiated with neutrons or X-rays and 2 d...

Phylogenetic relationships and taxonomic revision of Paranoplocephala Lühe, 1910 sensu lato (Cestoda, Cyclophyllidea, Anoplocephalidae)

USDA-ARS?s Scientific Manuscript database

An extensive phylogenetic analysis and genus-level taxonomic revision of Paranoplocephala Lühe, 1910 -like cestodes (Cyclophyllidea, Anoplocephalidae) are presented. The phylogenetic analysis is based on DNA sequences of two partial mitochondrial genes, i.e. cytochrome c oxidase subunit 1 (cox1) and...

Diversity at the Holarctic nexus: species of Arostrilepis (Eucestoda: Hymenolepididae) in arvicoline rodents (Cricetidae: Arvicolinae) from greater Beringia

USDA-ARS?s Scientific Manuscript database

Previously unrecognized species of hymenolepidid cestodes attributable to Arostrilepis Mas-Coma & Tenora, 1997 in arvicoline rodents from the greater Beringian region and western North America are described. Discovery and characterization of these tapeworms contributes to the recognition of a compl...

Niche partitioning in the cestode communities of two elasmobranchs

Treesearch

M. M. Friggens; J. H. Brown

2005-01-01

Several randomization methods have been used to investigate the influence of competitive interactions in shaping parasite community structure. Marine fish parasite communities have often been regarded as unstructured assemblages with little or no resource limitation and, therefore, not prone to competitive influences. In this study, null models were used to assess the...

Molecular identification of Taenia spp. In the Eurasian Lynx (Lynx lynx) from Finland

USDA-ARS?s Scientific Manuscript database

Cestodes of the genus Taenia are parasites of mammals, with mainly carnivores as definitive and herbivores as intermediate hosts. Various medium-sized cats, Lynx spp., are involved in the life cycles of several species of Taenia. The aim of the present study was to identify Taenia tapeworms in the E...

Dipylidium caninum (Cyclophyllidea, Dipylidiidae) in a wild carnivore from Brazil.

PubMed

Vieira, Fabiano M; Luque, José L; Lima, Sueli de Souza; Neto, Antonio H A de Moraes; Muniz-Pereira, Luís C

2012-01-01

We report Dipylidium caninum for the first time in a wild carnivore in Brazil, the crab-eating fox (Cerdocyon thous). Presence of the cestode could be the consequence of anthropogenic expansion into natural habitats of this host, as this parasite has only previously been reported in domestic hosts in Brazil.

A life cycle database for parasitic acanthocephalans, cestodes, and nematodes

USGS Publications Warehouse

Benesh, Daniel P.; Lafferty, Kevin D.; Kuris, Armand

2017-01-01

Parasitologists have worked out many complex life cycles over the last ~150 years, yet there have been few efforts to synthesize this information to facilitate comparisons among taxa. Most existing host-parasite databases focus on particular host taxa, do not distinguish final from intermediate hosts, and lack parasite life-history information. We summarized the known life cycles of trophically transmitted parasitic acanthocephalans, cestodes, and nematodes. For 973 parasite species, we gathered information from the literature on the hosts infected at each stage of the parasite life cycle (8510 host-parasite species associations), what parasite stage is in each host, and whether parasites need to infect certain hosts to complete the life cycle. We also collected life-history data for these parasites at each life cycle stage, including 2313 development time measurements and 7660 body size measurements. The result is the most comprehensive data summary available for these parasite taxa. In addition to identifying gaps in our knowledge of parasite life cycles, these data can be used to test hypotheses about life cycle evolution, host specificity, parasite life-history strategies, and the roles of parasites in food webs.

Hymenolepis folkertsi n. sp. (Eucestoda: Hymenolepididae) in the oldfield mouse Peromyscus polionotus (Wagner) (Rodentia: Cricetidae: Neotominae) from the southeastern Nearctic with comments on tapeworm faunal diversity among deer mice.

PubMed

Makarikov, Arseny A; Nims, Todd N; Galbreath, Kurt E; Hoberg, Eric P

2015-06-01

A previously unrecognized species of hymenolepidid cestode attributable to Hymenolepis is described based on specimens in Peromyscus polionotus, oldfield mouse, from Georgia near the southeastern coast of continental North America. Specimens of Hymenolepis folkertsi n. sp. differ from those attributed to most other species in the genus by having testes arranged in a triangle and a scolex with a prominent rostrum-like protrusion. The newly recognized species is further distinguished by the relative position and length of the cirrus sac, shape of seminal receptacle, and relative size of external seminal vesicle and seminal receptacle. Hymenolepidid cestodes have sporadically been reported among the highly diverse assemblage of Peromyscus which includes 56 distinct species in the Nearctic. Although the host genus has a great temporal duration and is endemic to the Nearctic, current evidence suggests that tapeworm faunal diversity reflects relatively recent assembly through bouts of host switching among other cricetid, murid, and geomyid rodents in sympatry.

A Common Eurasian Fish Tapeworm, Caryophyllaeides fennica (Cestoda), in Western North America: Further Evidence of 'Amphi-Pacific' Vicariance in Freshwater Fish Parasites.

PubMed

Oros, Mikuláš; Choudhury, Anindo; Scholz, Tomáš

2017-10-01

The freshwater fish faunas of the Palaearctic and Nearctic regions show similarities but also notable differences, resulting in diverse distributions of their parasites. Relatively few parasite species occur in both regions and fewer still have been examined using molecular data. We report a rare example of 'amphi-Pacific' distribution, involving the common Palaearctic parasite, the caryophyllidean cestode Caryophyllaeides fennica (Schneider, 1902), in the chiselmouth Acrocheilus alutaceus Agassiz and Pickering, 1855, an endemic cyprinid in northwestern Nearctic, Oregon. Available information on nonnative fish species in Oregon suggests that the parasite is native to the area and not introduced. Molecular data (18S ribosomal [r]DNA, 28S rDNA, internal transcribed spacer 2, and cytochrome c oxidase subunit 1 gene) indicate very little genetic divergence between representatives from the Palaearctic and Nearctic, and possibly a relatively more recent colonization of the Nearctic region by this cestode via the Beringian land bridge. This is remarkable considering that Acrocheilus has reportedly been in Oregon since the Miocene.

A new anoplocephalid (Cestoda: Cyclophyllidea) from Gallotia atlantica (Reptilia, Lacertidae) in the Canary Islands, Spain.

PubMed

Foronda, Pilar; Abreu-Acosta, Néstor; Casanova, Juan Carlos; Ribas, Alexis; Valladares, Basilio

2009-06-01

A new species of anoplocephalid cestode is described from Gallotia atlantica (Reptilia, Lacertidae) on the Canary Islands, Spain. Oochoristica feliui n. sp. belongs to the group of Oochoristica spp. having circular suckers and fewer than 25 testes in a single cluster: O. lygosomae Burt, 1933; O. lygosomatis Skinker, 1935; O. elongata Dupouy et Kechemir, 1973; O. jonnesi Bursey, McAllister and Freed, 1997; O. junkea Johri, 1950; O. macallisteri Bursey and Goldberg, 1996; O. novaezelandae Schmidt and Allison, 1985; O. parvogenitalis Dupouy and Kechemir, 1973; and O. sobolevi (Spasskii, 1948) Spaskii, 1951. Oochoristica feliui n. sp. differs from these species in a variety of characters such as the number of proglottids, size of the scolex and suckers, presence of a neck, size and shape of the ovary (divided into 5-6 lobules), ovoid shape of the vitelline gland, a spined cirrus, size of eggs, oncosphere and oncosphere hooks, and the presence of 2 osmoregulatory canals. Gallotia spp. are endemic to the Canary Islands. This is the first report of an adult cestode species in this lizard.

Molecular identification of Taenia mustelae cysts in subterranean rodent plateau zokors (Eospalax baileyi).

PubMed

Zhao, Fang; Ma, Jun-Ying; Cai, Hui-Xia; Su, Jian-Ping; Hou, Zhi-Bin; Zhang, Tong-Zuo; Lin, Gong-Hua

2014-07-01

Cestode larvae spend one phase of their two-phase life cycle in the viscera of rodents, but cases of cestodes infecting subterranean rodents have only been rarely observed. To experimentally gain some insight into this phenomenon, we captured approximately 300 plateau zokors (Eospalax baileyi), a typical subterranean rodent inhabiting the Qinghai-Tibet Plateau, and examined their livers for the presence of cysts. Totally, we collected five cysts, and using a mitochondrial gene (cox1) and two nuclear genes (pepck and pold) as genetic markers, we were able to analyze the taxonomy of the cysts. Both the maximum likelihood and Bayesian methods showed that the cysts share a monophyly with Taenia mustelae, while Kimura 2-parameter distances and number of different sites between our sequences and T. mustelae were far less than those found between the examined sequences and other Taeniidae species. These results, alongside supporting paraffin section histology, imply that the cysts found in plateau zokors can be regarded as larvae of T. mustelae, illustrating that zokors are a newly discovered intermediate host record of this parasite.

A simple method for collecting eggs of taeniid cestodes from fresh, frozen or ethanol-fixed segments.

PubMed

Takemoto, Y; Negita, T; Ohnishi, K; Suzuki, M; Ito, A

1995-04-01

A simple method was devised for collecting eggs of Taenia taeniaeformis and T. saginata. All gravid segments, either fresh or frozen or 70% ethanol-fixed, were gently scraped using a pestle on a 150 mesh stainless steel sieve. Eggs and tissue debris were washed out all together with mouse tonicity phosphate buffered saline (MTPBS) through the 150 mesh sieve into a glass beaker. Egg suspension with a huge amount of tissue debris in MTPBS was centrifuged 5 min at 3000 r.p.m. (x 1600 g) and the pellet of eggs and tissue debris was resuspended with 1 vol. of MTPBS and 2 vol. of Percoll (Pharmacia) and centrifuged 60 min at 3000 r.p.m. More than 90% of eggs sedimented in the pellet. The supernatant covered with tissue debris was decanted, and the egg pellet was resuspended and centrifuged several times with MTPBS to remove Percoll. It is suggested that this simple method may prove useful for preparation of eggs of biohazardous taeniid cestodes, such as Taenia solium and Echinococcus spp.

Molecular identification of Taenia mustelae cysts in subterranean rodent plateau zokors (Eospalax baileyi)

PubMed Central

ZHAO, Fang; ZHANG, Ming-Xia; MA, Jun-Ying; CAI, Hui-Xia; SU, Jian-Ping; CAI, Hui-Xia; HOU, Zhi-Bin; ZHANG, Tong-Zuo; LIN, Gong-Hua

2014-01-01

Cestode larvae spend one phase of their two-phase life cycle in the viscera of rodents, but cases of cestodes infecting subterranean rodents have only been rarely observed. To experimentally gain some insight into this phenomenon, we captured approximately 300 plateau zokors (Eospalax baileyi), a typical subterranean rodent inhabiting the Qinghai-Tibet Plateau, and examined their livers for the presence of cysts. Totally, we collected five cysts, and using a mitochondrial gene (cox1) and two nuclear genes (pepck and pold) as genetic markers, we were able to analyze the taxonomy of the cysts. Both the maximum likelihood and Bayesian methods showed that the cysts share a monophyly with Taenia mustelae, while Kimura 2-parameter distances and number of different sites between our sequences and T. mustelae were far less than those found between the examined sequences and other Taeniidae species. These results, alongside supporting paraffin section histology, imply that the cysts found in plateau zokors can be regarded as larvae of T. mustelae, illustrating that zokors are a newly discovered intermediate host record of this parasite. PMID:25017751

A Transcriptomic Analysis of Echinococcus granulosus Larval Stages: Implications for Parasite Biology and Host Adaptation

PubMed Central

Parkinson, John; Wasmuth, James D.; Salinas, Gustavo; Bizarro, Cristiano V.; Sanford, Chris; Berriman, Matthew; Ferreira, Henrique B.; Zaha, Arnaldo; Blaxter, Mark L.; Maizels, Rick M.; Fernández, Cecilia

2012-01-01

Background The cestode Echinococcus granulosus - the agent of cystic echinococcosis, a zoonosis affecting humans and domestic animals worldwide - is an excellent model for the study of host-parasite cross-talk that interfaces with two mammalian hosts. To develop the molecular analysis of these interactions, we carried out an EST survey of E. granulosus larval stages. We report the salient features of this study with a focus on genes reflecting physiological adaptations of different parasite stages. Methodology/Principal Findings We generated ∼10,000 ESTs from two sets of full-length enriched libraries (derived from oligo-capped and trans-spliced cDNAs) prepared with three parasite materials: hydatid cyst wall, larval worms (protoscoleces), and pepsin/H+-activated protoscoleces. The ESTs were clustered into 2700 distinct gene products. In the context of the biology of E. granulosus, our analyses reveal: (i) a diverse group of abundant long non-protein coding transcripts showing homology to a middle repetitive element (EgBRep) that could either be active molecular species or represent precursors of small RNAs (like piRNAs); (ii) an up-regulation of fermentative pathways in the tissue of the cyst wall; (iii) highly expressed thiol- and selenol-dependent antioxidant enzyme targets of thioredoxin glutathione reductase, the functional hub of redox metabolism in parasitic flatworms; (iv) candidate apomucins for the external layer of the tissue-dwelling hydatid cyst, a mucin-rich structure that is critical for survival in the intermediate host; (v) a set of tetraspanins, a protein family that appears to have expanded in the cestode lineage; and (vi) a set of platyhelminth-specific gene products that may offer targets for novel pan-platyhelminth drug development. Conclusions/Significance This survey has greatly increased the quality and the quantity of the molecular information on E. granulosus and constitutes a valuable resource for gene prediction on the parasite genome and for further genomic and proteomic analyses focused on cestodes and platyhelminths. PMID:23209850

Histological damage and inflammatory response elicited by Monobothrium wageneri (Cestoda) in the intestine of Tinca tinca (Cyprinidae)

PubMed Central

2011-01-01

Background Among the European cyprinids, tench, Tinca tinca (L.), and the pathological effects their cestodes may effect, have received very little or no attention. Most literature relating to Monobothrium wageneri Nybelin, 1922, a common intestinal cestode of tench, for example, has focused on aspects of its morphology rather than on aspects of the host-parasite interaction. Results Immunopathological and ultrastructural studies were conducted on the intestines of 28 tench, collected from Lake Piediluco, of which 16 specimens harboured tight clusters of numerous M. wageneri attached to the intestinal wall. The infection was associated with the degeneration of the mucosal layer and the formation of raised inflammatory swelling surrounding the worms. At the site of infection, the number of granulocytes in the intestine of T. tinca was significantly higher than the number determined 1 cm away from the site of infection or the number found in uninfected fish. Using transmission electron microscopy, mast cells and neutrophils were frequently observed in close proximity to, and inside, the intestinal capillaries; often these cells were in contact with the cestode tegument. At the host-parasite interface, no secretion from the parasite's tegument was observed. Intense degranulation of the mast cells was seen within the submucosa and lamina muscularis, most noticeably at sites close to the tegument of the scolex. In some instances, rodlet cells were encountered in the submucosa. In histological sections, hyperplasia of the mucous cells, notably those giving an alcian blue positive reaction, were evident in the intestinal tissues close to the swelling surrounding the worms. Enhanced mucus secretion was recorded in the intestines of infected tench. Conclusions The pathological changes and the inflammatory cellular response induced by the caryophyllidean monozoic tapeworm M. wageneri within the intestinal tract of an Italian population of wild tench is reported for the first time. PMID:22152408

Functional diversity of secreted cestode Kunitz proteins: Inhibition of serine peptidases and blockade of cation channels

PubMed Central

Fló, Martín; Margenat, Mariana; Pellizza, Leonardo; Durán, Rosario; Salceda, Emilio; Alvarez, Beatriz

2017-01-01

We previously reported a multigene family of monodomain Kunitz proteins from Echinococcus granulosus (EgKU-1-EgKU-8), and provided evidence that some EgKUs are secreted by larval worms to the host interface. In addition, functional studies and homology modeling suggested that, similar to monodomain Kunitz families present in animal venoms, the E. granulosus family could include peptidase inhibitors as well as channel blockers. Using enzyme kinetics and whole-cell patch-clamp, we now demonstrate that the EgKUs are indeed functionally diverse. In fact, most of them behaved as high affinity inhibitors of either chymotrypsin (EgKU-2-EgKU-3) or trypsin (EgKU-5-EgKU-8). In contrast, the close paralogs EgKU-1 and EgKU-4 blocked voltage-dependent potassium channels (Kv); and also pH-dependent sodium channels (ASICs), while showing null (EgKU-1) or marginal (EgKU-4) peptidase inhibitory activity. We also confirmed the presence of EgKUs in secretions from other parasite stages, notably from adult worms and metacestodes. Interestingly, data from genome projects reveal that at least eight additional monodomain Kunitz proteins are encoded in the genome; that particular EgKUs are up-regulated in various stages; and that analogous Kunitz families exist in other medically important cestodes, but not in trematodes. Members of this expanded family of secreted cestode proteins thus have the potential to block, through high affinity interactions, the function of host counterparts (either peptidases or cation channels) and contribute to the establishment and persistence of infection. From a more general perspective, our results confirm that multigene families of Kunitz inhibitors from parasite secretions and animal venoms display a similar functional diversity and thus, that host-parasite co-evolution may also drive the emergence of a new function associated with the Kunitz scaffold. PMID:28192542

Chemotherapeutic effects of 4-isothiocyanato-4'-nitrodiphenylamine (C9333-Go/CGP 4540) on infections with Nematospiroides dubius, Hymenolepis diminuta, Hymenolepis nana and Spirometra mansonoides.

PubMed

Middleton, K R; Schaefer, F W; Saz, H J

1979-02-15

4-Isothiocyanato-4'-nitrodiphenylamine possessed anthelmintic activity against Nippostrongylus dubius and Hymenolepis nana in mice and H. diminuta in rats as determined by both egg counts and recovery of parasites at autopsy. No activity was detected against the cestode. Spirometra mansonoides, in cats.

Hymenolepis folkertsi n. sp. (Eucestoda: Hymenolepididae) in the oldfield mouse Peromyscus polionotus from the southeastern Nearctic with comments on tapeworm faunal diversity among deer mice

USDA-ARS?s Scientific Manuscript database

A previously unrecognized species of hymenolepidid cestode attributable to Hymenolepis Weinland, 1858 is described based on specimens in Peromyscus polionotus, oldfield mouse, from Georgia near the southeastern coast of continental North America. Specimens of Hymenolepis folkertsi n. sp. differ from...

The Environmental Evaluation Work Group: FY 1979 Studies of the Winter Navigation Demonstration Program, St. Lawrence River Fisheries Study

DTIC Science & Technology

1979-07-31

examined were infected with black spot, the externally encysted stage of the tremetode ( Uvulifer ambloplitis ). At Chimney Bay and Tibbits Creek, 7...and liver surface from 124 perch revealed that 112 (90.3%) were infected with cestodes, believed to be bass tapeworm (Proteocephalus ambloplitis ) or

Cystic pulmonary hydatidosis

PubMed Central

Sarkar, Malay; Pathania, Rajnish; Jhobta, Anupam; Thakur, Babu Ram; Chopra, Rajesh

2016-01-01

Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by the larval stages of the cestode Echinococcus granulosus. Worldwide, pulmonary hydatid cyst is a significant problem medically, socially, and economically. Surgery is the definitive therapy of pulmonary hydatidosis. Benzimidazoles may be considered in patients with a surgical contraindication. This review will focus on pathogenesis, lifecycle, clinical features, and management of pulmonary hydatid disease. PMID:27051107

A checklist of helminth parasites of Elasmobranchii in Mexico.

PubMed

Merlo-Serna, Aldo Iván; García-Prieto, Luis

2016-01-01

A comprehensive and updated summary of the literature and unpublished records contained in scientific collections on the helminth parasites of the elasmobranchs from Mexico is herein presented for the first time. At present, the helminth fauna associated with Elasmobranchii recorded in Mexico is composed of 132 (110 named species and 22 not assigned to species), which belong to 70 genera included in 27 families (plus 4 incertae sedis families of cestodes). These data represent 7.2% of the worldwide species richness. Platyhelminthes is the most widely represented, with 128 taxa: 94 of cestodes, 22 of monogeneans and 12 of trematodes; Nematoda and Annelida: Hirudinea are represented by only 2 taxa each. These records come from 54 localities, pertaining to 15 states; Baja California Sur (17 sampled localities) and Baja California (10), are the states with the highest species richness: 72 and 54 species, respectively. Up to now, 48 elasmobranch species have been recorded as hosts of helminths in Mexico; so, approximately 82% of sharks and 67% of rays distributed in Mexican waters lack helminthological studies. The present list provides the host, distribution (with geographical coordinates), site of infection, accession number in scientific collections, and references for the parasites. A host-parasite list is also provided.

Identification of candidate mimicry proteins involved in parasite-driven phenotypic changes.

PubMed

Hebert, Francois Olivier; Phelps, Luke; Samonte, Irene; Panchal, Mahesh; Grambauer, Stephan; Barber, Iain; Kalbe, Martin; Landry, Christian R; Aubin-Horth, Nadia

2015-04-15

Endoparasites with complex life cycles are faced with several biological challenges, as they need to occupy various ecological niches throughout their development. Host phenotypes that increase the parasite's transmission rate to the next host have been extensively described, but few mechanistic explanations have been proposed to describe their proximate causes. In this study we explore the possibility that host phenotypic changes are triggered by the production of mimicry proteins from the parasite by using an ecological model system consisting of the infection of the threespine stickleback (Gasterosteus aculeatus) by the cestode Schistocephalus solidus. Using RNA-seq data, we assembled 9,093 protein-coding genes from which ORFs were predicted to generate a reference proteome. Based on a previously published method, we built two complementary analysis pipelines to i) establish a general classification of protein similarity among various species (pipeline A) and ii) identify candidate mimicry proteins showing specific host-parasite similarities (pipeline B), a key feature underlying the possibility of molecular mimicry. Ninety-four tapeworm proteins showed high local sequence homology with stickleback proteins. Four of these candidates correspond to secreted or membrane proteins that could be produced by the parasite and eventually be released in or be in contact with the host to modulate physiological pathways involved in various phenotypes (e.g. behaviors). One of these candidates belongs to the Wnt family, a large group of signaling molecules involved in cell-to-cell interactions and various developmental pathways. The three other candidates are involved in ion transport and post-translational protein modifications. We further confirmed that these four candidates are expressed in three different developmental stages of the cestode by RT-PCR, including the stages found in the host. In this study, we identified mimicry candidate peptides from a behavior-altering cestode showing specific sequence similarity with host proteins. Despite their potential role in modulating host pathways that could lead to parasite-induced phenotypic changes and despite our confirmation that they are expressed in the developmental stage corresponding to the altered host behavior, further investigations will be needed to confirm their mechanistic role in the molecular cross-talk taking place between S. solidus and the threespine stickleback.

RNA interference in a cestode reveals specific silencing of selected highly expressed gene transcripts.

PubMed

Pierson, Lisa; Mousley, Angela; Devine, Lynda; Marks, Nikki J; Day, Tim A; Maule, Aaron G

2010-04-01

Evolving RNA interference (RNAi) platforms are providing opportunities to probe gene function in parasitic helminths using reverse genetics. Although relatively robust methods for the application of RNAi in parasitic flatworms have been established, reports of successful RNAi are confined to three genera and there are no known reports of the application of RNAi to the class Cestoda. Here we report the successful application of RNAi to a cestode. Our target species was the common ruminant tapeworm, Moniezia expansa which can significantly impact the health/productivity of cattle, sheep and goats. Initial efforts aimed to silence the neuronally expressed neuropeptide F gene (Me-npf-1), which encodes one of the most abundant neuropeptides in flatworms and a homologue of vertebrate neuropeptide Y (NPY). Double stranded (ds)RNAs, delivered by electroporation and soaking (4-8h), failed to trigger consistent Me-npf-1 transcript knock-down in adult worms; small interfering RNAs (siRNAs) were also ineffective. Identical approaches resulted in significant and consistent transcript knock-down of actin transcript (71+/-4%) following soaking in Me-act-1 dsRNA. Similar successes were seen with hydrophobic lipid-binding protein (Me-lbp-1), with a dsRNA inducing significant target transcript reduction (72+/-5%). To confirm the validity of the observed transcript knock-downs we further investigated Me-act-1 RNAi worms for associated changes in protein levels, morphology and phenotype. Me-act-1 RNAi worms displayed significant reductions in both filamentous actin immunostaining (62+/-3%) and the amount of actin detected in Western blots (54+/-13%). Morphologically, Me-act-1 RNAi worms displayed profound tegumental disruption/blebbing. Further, muscle tension recordings from Me-act-1 RNAi worms revealed a significant reduction in both the number of worms contracting in response to praziquantel (20+/-12%) and in their contractile ability. These data demonstrate, to our knowledge for the first time, a functional RNAi pathway in a cestode and show that the robust knock-down of abundant gene transcripts is achievable using long dsRNAs following short exposure times. 2009 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

A checklist of helminth parasites of Elasmobranchii in Mexico

PubMed Central

Merlo-Serna, Aldo Iván; García-Prieto, Luis

2016-01-01

Abstract A comprehensive and updated summary of the literature and unpublished records contained in scientific collections on the helminth parasites of the elasmobranchs from Mexico is herein presented for the first time. At present, the helminth fauna associated with Elasmobranchii recorded in Mexico is composed of 132 (110 named species and 22 not assigned to species), which belong to 70 genera included in 27 families (plus 4 incertae sedis families of cestodes). These data represent 7.2% of the worldwide species richness. Platyhelminthes is the most widely represented, with 128 taxa: 94 of cestodes, 22 of monogeneans and 12 of trematodes; Nematoda and Annelida: Hirudinea are represented by only 2 taxa each. These records come from 54 localities, pertaining to 15 states; Baja California Sur (17 sampled localities) and Baja California (10), are the states with the highest species richness: 72 and 54 species, respectively. Up to now, 48 elasmobranch species have been recorded as hosts of helminths in Mexico; so, approximately 82% of sharks and 67% of rays distributed in Mexican waters lack helminthological studies. The present list provides the host, distribution (with geographical coordinates), site of infection, accession number in scientific collections, and references for the parasites. A host-parasite list is also provided. PMID:27047240

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.

PubMed

Brunanská, Magdaléna; Scholz, Tomás; Ibraheem, Mohammed Hassan

2004-06-01

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.

Platynosomum fastosum-induced chronic intrahepatic cholangitis and Spirometra spp. infections in feral cats from Grand Cayman.

PubMed

Headley, S A; Gillen, M A; Sanches, A W D; Satti, M Z

2012-06-01

The occurrence of platynosomiasis and intestinal sparganosis is described in feral cats from Grand Cayman, Cayman Islands. Spirometra spp. was observed within the intestine of 18.18% (10/55) of cats; 1.18% (1/55) of cats demonstrated gross and histological manifestation of parasitism by Platynosomum fastosum, but 14.5% (8/55) of cats had the characteristic pathological manifestations of P. fastosum-induced intrahepatic cholangitis without the concomitant presence of the intraductal trematode. Combined parasitism (Spirometra spp. and P. fastosum) was observed in 9.09% (5/55) of feral cats. Significant pathological findings were only associated with the hepatic fluke, P. fastosum, and were grossly characterized by moderate hepatomegaly with enlarged and dilated bile ducts. Examples of cestodes with morphological features characteristic of Spirometra spp. were observed within the small intestine without any associated pathological lesion. The histopathological evaluation of liver fragments revealed chronic intrahepatic cholangitis with and without the associated intraductal trematode, and was characterized by marked periductal fibrosis, adenomatous proliferation of bile duct epithelium, dilation of intrahepatic bile ducts and portal accumulations of inflammatory cells. The occurrence of the cestode in feral cats coupled with factors that are unique to Grand Cayman makes this island the ideal location for sporadic cases of human sparganosis.

Impact of the cestode Triaenophorus nodulosus on the exotic Lepomis gibbosus and the autochthonous Perca fluviatilis.

PubMed

Masson, G; Vanacker, M; Fox, M G; Beisel, J-N

2015-05-01

The effects of plerocercoids of the cestode Triaenophorus nodulosus infecting the livers of native Eurasian perch Perca fluviatilis and non-native pumpkinseed Lepomis gibbosus was investigated in 17 sites along the Moselle watershed. With a single exception, infected individuals were not observed in the main channel whether or not northern pike Esox lucius, a final host, was present. In ponds where the pike was present, the prevalence of T. nodulosus averaged 86% in Eurasian perch and 15% in pumpkinseed. The parasite was not present at all in ponds when pike were absent. Parasite load, hepatosomatic index (HSI), gonadosomatic index (GSI) and body condition index (CI) were compared between hosts in one site where parasite prevalence and fish abundance was highest. HSI in infected perch was significantly higher than in uninfected perch, whereas no differences in HSI were detected between infected and uninfected pumpkinseed. While perch were more frequently infected and had a greater average parasite load than pumpkinseed, there were no significant differences in either indicator between the two species. Furthermore, no significant differences in GSI or CI were observed between infected and uninfected fish in either species, by either gender or maturity stage. We hypothesize that pumpkinseed is more resistant to the parasite or less likely to feed upon infected copepods than perch.

Lineage-specific expansion and loss of tyrosinase genes across platyhelminths and their induction profiles in the carcinogenic oriental liver fluke, Clonorchis sinensis.

PubMed

Kim, Seon-Hee; Bae, Young-An

2017-09-01

Tyrosinase provides an essential activity during egg production in diverse platyhelminths by mediating sclerotization of eggshells. In this study, we investigated the genomic and evolutionary features of tyrosinases in parasitic platyhelminths whose genomic information is available. A pair of paralogous tyrosinases was detected in most trematodes, whereas they were lost in cyclophyllidean cestodes. A pseudophyllidean cestode displaying egg biology similar to that of trematodes possessed an orthologous gene. Interestingly, one of the paralogous tyrosinases appeared to have been multiplied into three copies in Clonorchis sinensis and Opisthorchis viverrini. In addition, a fifth tyrosinase gene that was minimally transcribed through all developmental stages was further detected in these opisthorchiid genomes. Phylogenetic analyses demonstrated that the tyrosinase gene has undergone duplication at least three times in platyhelminths. The additional opisthorchiid gene arose from the first duplication. A paralogous copy generated from these gene duplications, except for the last one, seemed to be lost in the major neodermatans lineages. In C. sinensis, tyrosinase gene expressions were initiated following sexual maturation and the levels were significantly enhanced by the presence of O2 and bile. Taken together, our data suggest that tyrosinase has evolved lineage-specifically across platyhelminths related to its copy number and induction mechanism.

Cloning and characterization of the fatty acid-binding protein gene from the protoscolex of Taenia multiceps.

PubMed

Nie, Hua-Ming; Xie, Yue; Fu, Yan; Yang, Ying-Dong; Gu, Xiao-Bin; Wang, Shu-Xian; Peng, Xi; Lai, Wei-Ming; Peng, Xue-Rong; Yang, Guang-You

2013-05-01

Taenia multiceps (Cestoda: Taeniidae), a worldwide cestode parasite, is emerging as an important helminthic zoonosis due to serious or fatal central nervous system disease commonly known as coenurosis in domestic and wild ruminants including humans. Herein, a fatty acid-binding protein (FABP) gene was identified from transcriptomic data in T. multiceps. This gene, which contains a complete coding sequence, was amplified by reverse-transcriptase polymerase chain reaction. The corresponding protein, which was named TmFABP, had a molecular weight of 14 kDa, and subsequently was recombinantly expressed in Escherichia coli. The fusion protein was purified on Ni-NTA beads (Bio-Rad). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analyses showed that the purified recombinant protein caused immunogenicity. Immunohistochemical studies showed that TmFABP was expressed at the tegumental level in the protoscolices and in the cells between the body wall and parenchyma layer of the cestode. In sections from gravid proglottids, intense staining was detected in the uterus and eggs. Based on this, TmFABP could be switched on during differentiation of germinative layers to protoscoleces and from metacestodes to adult worms. Taken together, our results already reported for T. multiceps suggest the possibility of TmFABP developing a vaccine to control and prevent coenurosis.

A dual PCR-based sequencing approach for the identification and discrimination of Echinococcus and Taenia taxa.

PubMed

Boubaker, Ghalia; Marinova, Irina; Gori, Francesca; Hizem, Amani; Müller, Norbert; Casulli, Adriano; Jerez Puebla, Luis Enrique; Babba, Hamouda; Gottstein, Bruno; Spiliotis, Markus

2016-08-01

Reliable and rapid molecular tools for the genetic identification and differentiation of Echinococcus species and/or genotypes are crucial for studying spatial and temporal transmission dynamics. Here, we describe a novel dual PCR targeting regions in the small (rrnS) and large (rrnL) subunits of mitochondrial ribosomal RNA (rRNA) genes, which enables (i) the specific identification of species and genotypes of Echinococcus (rrnS + L-PCR) and/or (ii) the identification of a range of taeniid cestodes, including different species of Echinococcus, Taenia and some others (17 species of diphyllidean helminths). This dual PCR approach was highly sensitive, with an analytical detection limit of 1 pg for genomic DNA of Echinococcus. Using concatenated sequence data derived from the two gene markers (1225 bp), we identified five unique and geographically informative single nucleotide polymorphisms (SNPs) that allowed genotypes (G1 and G3) of Echinococcus granulosus sensu stricto to be distinguished, and 25 SNPs that allowed differentiation within Echinococcus canadensis (G6/7/8/10). In conclusion, we propose that this dual PCR-based sequencing approach can be used for molecular epidemiological studies of Echinococcus and other taeniid cestodes. Copyright © 2016 Elsevier Ltd. All rights reserved.

In Vitro Ovicidal and Cestocidal Effects of Toxins from Bacillus thuringiensis on the Canine and Human Parasite Dipylidium caninum

PubMed Central

Peña, Guadalupe; Aguilar Jiménez, Fortino Agustín; Hallal-Calleros, Claudia; Morales-Montor, Jorge; Hernández-Velázquez, Víctor Manuel; Flores-Pérez, Fernando Iván

2013-01-01

Bacillus thuringiensis is a gram-positive soil-dwelling bacterium that is commonly used as a biological pesticide. This bacterium may also be used for biological control of helminth parasites in domestic animals. In this study, we evaluated the possible ovicidal and cestocidal effects of a total protein extract of B. thuringiensis native strains on the zoonotic cestode parasite of dogs, Dipylidium caninum (D. caninum). Dose and time response curves were determined by coincubating B. thuringiensis proteins at concentration ranging from 100 to 1000 μg/mL along with 4000 egg capsules of D. caninum. Egg viability was evaluated using the trypan blue exclusion test. The lethal concentration of toxins on eggs was 600 μg/ml, and the best incubation time to produce this effect was 3 h. In the adult stage, the motility and the thickness of the tegument were used as indicators of damage. The motility was inhibited by 100% after 8 hours of culture compared to the control group, while the thickness of the cestode was reduced by 34%. Conclusively, proteins of the strain GP526 of B. thuringiensis directly act upon D. caninum showing ovicidal and cestocidal effects. Thus, B. thuringiensis is proposed as a potential biological control agent against this zoonosis. PMID:23484087

In vitro ovicidal and cestocidal effects of toxins from Bacillus thuringiensis on the canine and human parasite Dipylidium caninum.

PubMed

Peña, Guadalupe; Aguilar Jiménez, Fortino Agustín; Hallal-Calleros, Claudia; Morales-Montor, Jorge; Hernández-Velázquez, Víctor Manuel; Flores-Pérez, Fernando Iván

2013-01-01

Bacillus thuringiensis is a gram-positive soil-dwelling bacterium that is commonly used as a biological pesticide. This bacterium may also be used for biological control of helminth parasites in domestic animals. In this study, we evaluated the possible ovicidal and cestocidal effects of a total protein extract of B. thuringiensis native strains on the zoonotic cestode parasite of dogs, Dipylidium caninum (D. caninum). Dose and time response curves were determined by coincubating B. thuringiensis proteins at concentration ranging from 100 to 1000 μ g/mL along with 4000 egg capsules of D. caninum. Egg viability was evaluated using the trypan blue exclusion test. The lethal concentration of toxins on eggs was 600 μ g/ml, and the best incubation time to produce this effect was 3 h. In the adult stage, the motility and the thickness of the tegument were used as indicators of damage. The motility was inhibited by 100% after 8 hours of culture compared to the control group, while the thickness of the cestode was reduced by 34%. Conclusively, proteins of the strain GP526 of B. thuringiensis directly act upon D. caninum showing ovicidal and cestocidal effects. Thus, B. thuringiensis is proposed as a potential biological control agent against this zoonosis.

Lanfrediella amphicirrus gen. nov. sp. nov. Nematotaeniidae (Cestoda: Cyclophyllidea), a tapeworm parasite of Rhinella marina (Linnaeus, 1758) (Amphibia: Bufonidae).

PubMed

Melo, Francisco Tiago de Vasconcelos; Giese, Elane Guerreiro; Furtado, Adriano Penha; Soares, Maurílio José; Gonçalves, Evonnildo Costa; Vallinoto, Antonio Carlos Rosário; Santos, Jeannie Nascimento dos

2011-09-01

The family Nematotaeniidae, tapeworms commonly found in the small intestines of amphibians and reptiles, includes 27 recognised species distributed among four genera: Bitegmen Jones, Cylindrotaenia Jewell, Distoichometra Dickey and Nematotaenia Lühe. The taxonomy of these cestodes is poorly defined, due in part to the difficulties of observing many anatomical traits. This study presents and describes a new genus and species of nematotaeniid parasite found in cane toads (Rhinella marina) from eastern Brazilian Amazonia. The cestodes were collected during the necropsy of 20 hosts captured in the urban area of Belém, Pará. The specimens were fixed and processed for light microscopy, scanning electron microscopy (SEM) and three-dimensional (3D) reconstruction. Samples were also collected for molecular analyses. The specimens presented a cylindrical body, two testes and paruterine organs. However, they could not be allocated to any of the four existing nematotaeniid genera due to the presence of two each of dorsal compact medullary testes, cirri, cirrus pouches, genital pores, ovaries and vitelline glands per mature segment. Lanfrediella amphicirrus gen. nov. sp. nov. is the first nematotaeniid studied using Historesin analysis, SEM and 3D reconstruction, and it is the second taxon for which molecular data have been deposited in GenBank.

Echinococcosis: historical landmarks and progress in research and control.

PubMed

Moro, P L; Schantz, P M

2006-12-01

Although hydatid cysts were recognised and described in ancient times, in both livestock and humans, it was not until the 17th Century that their biological nature began to be understood. The past 50 years have seen a veritable revolution in knowledge and technology applicable to the biology of the cestodes and the diseases they cause. The parasites that form hydatid cysts belong to the genus Echinococcus, which is now recognized as a complex of closely related cestode parasites adapted to a variety of host-assemblages linked by predator-prey relationships. Synanthropic transmission in dogs and domestic livestock greatly increases the possibilities of zoonotic transmission, and the highest prevalences of Echinococcus infection in humans therefore occur in populations engaged in livestock rearing in which domestic dogs have access to the viscera of the livestock that serve as intermediate hosts. The application of modern scientific technology over the last few decades has not only revealed the diversity of host-parasite relationships within the genus Echinococcus but also led to greatly improved technology for the diagnosis and treatment of the echinococcoses in humans and lower animals. Although control programmes have led to marked reductions in transmission in certain geographical and socio-political settings, transmission and the resultant diseases continue unabated throughout most of the parasites' world-wide distribution.

Longitudinal study of parasite-induced mortality of a long-lived host: the importance of exposure to non-parasitic stressors.

PubMed

Chin, Hilary M-H; Luong, Lien T; Shostak, Allen W

2017-12-01

Hosts face mortality from parasitic and environmental stressors, but interactions of parasitism with other stressors are not well understood, particularly for long-lived hosts. We monitored survival of flour beetles (Tribolium confusum) in a longitudinal design incorporating cestode (Hymenolepis diminuta) infection, starvation and exposure to the pesticide diatomaceous earth (DE). We found that cestode cysticercoids exhibit increasing morphological damage and decreasing ability to excyst over time, but were never eliminated from the host. In the presence of even mild environmental stressors, host lifespan was reduced sufficiently that extensive degradation of cysticercoids was never realized. Median host lifespan was 200 days in the absence of stressors, and 3-197 days with parasitism, starvation and/or DE. Early survival of parasitized hosts was higher relative to controls in the presence of intermediate concentrations of DE, but reduced under all other conditions tested. Parasitism increased host mortality in the presence of other stressors at times when parasitism alone did not cause mortality, consistent with an interpretation of synergy. Environmental stressors modified the parasite numbers needed to reveal intensity-dependent host mortality, but only rarely masked intensity dependence. The longitudinal approach produced observations that would have been overlooked or misinterpreted if survival had only been monitored at a single time point.

Intestinal obstruction caused by Taenia taeniaeformis infection in a cat.

PubMed

Wilcox, Rebbecca S; Bowman, Dwight D; Barr, Stephen C; Euclid, James M

2009-01-01

An adult domestic shorthair (DSH) cat was presented with acute vomiting, anorexia, lethargy, and dyspnea. The cat's clinical status worsened over 24 hours with conservative medical management. An exploratory celiotomy was performed. Acute intestinal obstruction resulting from infection with Taenia (T.) taeniaeformis was diagnosed. Surgical removal of the cestodes via multiple enterotomies resolved the obstruction. This paper reports, for the first time, small intestinal obstruction caused by T. taeniaeformis infection in a cat.

'Global worming': first record of an epidemic of Triaenophorus crassus in a population of Arctic charr Salvelinus umbla.

PubMed

Achleitner, D; Gassner, H; Schabetsberger, R

2009-03-01

In May 2005, an epidemic of the cestode Triaenophorus crassus occurred in the Salvelinus umbla population of Lake Grundlsee, an oligotrophic Austrian Alpine Lake. Based on catches with a standardized multi-mesh gillnet survey 53% of S. umbla were infected with up to 17 cysts of T. crassus per fish. This is the first documented record of an epidemic of this tapeworm in S. umbla.

The parasite assemblage in the spiral intestine of the shark Mustelus canis.

PubMed

Cislo, P R; Caira, J N

1993-12-01

The parasite assemblage in the 8 chambers of the spiral intestine of 49 specimens of the shark Mustelus canis collected from Long Island Sound and off the coast of Virginia was investigated. Assemblages within host individuals were composed of up to 3 of 4 species of cestodes: the trypanorhynch species Prochristianella tumidula and Lacistorhynchus tenuis and the hooked tetraphyllidean species Calliobothrium verticillatum and Calliobothrium lintoni. Each individual shark hosted 1-3 (mean = 2.17) tapeworm species and 1-166 (mean = 34.3) tapeworm individuals. The assemblage consisted of 2 core species, 1 secondary species, and 1 satellite species. Analysis of variance (ANOVA) revealed significant differences among the areas of the 8 intestinal chambers. ANOVAs of worm density among chambers revealed that each of the 4 species exhibited site specificity within the spiral intestine. Least significant difference analysis revealed that each of the species, except C. verticillatum, was usually found in the anterior 3 chambers. Calliobothrium verticillatum was more commonly found in the middle region of the organ, centered around chamber 4. Horn's information index indicated that L. tenuis and C. lintoni had the greatest amount of overlap within the spiral intestine and the congeners C. lintoni and C. verticillatum had the least amount of overlap. No evidence of interaction among the species in this assemblage was found. In cases where observations could be made, neither cestode total length nor location within the spiral intestine appeared to be affected by the presence of other individuals or species respectively. There was some evidence of underutilized space; the posteriormost chamber was vacant in all 49 sharks examined and 91.8% of sharks had at least 2 vacant chambers. Linear regression revealed no relationship between shark total length and either total number of worms or total number of individuals of each of the 4 species of cestodes. The chi-square test revealed no evidence that the 4 species do not occur independently among host individuals. The number of species and number of individuals in M. canis were low when compared to the marine fish Sebastes nebulosus. These values for M. canis more closely resemble values for freshwater fishes. The comparatively much greater host specificity of these tapeworms may at least partially account for this difference. We propose that site specificity may have a phylogenetic component, in a manner similar to that of host specificity.

myo-Inositol hexakisphosphate is a major component of an extracellular structure in the parasitic cestode Echinococcus granulosus.

PubMed Central

Irigoín, Florencia; Ferreira, Fernando; Fernández, Cecilia; Sim, Robert B; Díaz, Alvaro

2002-01-01

myo-Inositol hexakisphosphate (IP(6)) is an abundant intracellular component of animal cells. In this study we describe the presence of extracellular IP(6) in the hydatid cyst wall (HCW) of the larval stage of the cestode parasite Echinococcus granulosus. The HCW comprises an inner cellular layer and an outer, acellular (laminated) layer up to 2 mm in thickness that protects the parasite from host immune cells. A compound, subsequently identified as IP(6), was detected in and purified from an HCW extract on the basis of its capacity to inhibit complement activation. The identification of the isolated compound was carried out by a combination of NMR, MS and TLC. The majority of IP(6) in the HCW was found in the acellular layer, with only a small fraction of the compound being extracted from cells. In the laminated layer, IP(6) was present in association with calcium, and accounted for up to 15% of the total dry mass of the HCW. IP(6) was not detected in any other structures or stages of the parasite. Our results imply that IP(6) is secreted by the larval stage of the parasite in a polarized fashion towards the interface with the host. This is the first report of the secretion of IP(6), and the possible implications beyond the biology of E. granulosus are discussed. PMID:11853537

Intestinal helminths of feral cat populations from urban and suburban districts of Qatar.

PubMed

Abu-Madi, Marawan A; Behnke, Jerzy M; Prabhaker, K S; Al-Ibrahim, Roda; Lewis, John W

2010-03-25

A survey of the helminths of 658 adult cats from feral urban and suburban populations in Qatar was conducted across all months in 2006 and 2007. Six species of helminths were identified, comprising two cestodes (Taenia taeniaeformis [73.6%] and Diplopylidium acanthotetra [47.1%]) and four nematodes (Ancylostoma tubaeforme [14.7%], Physaloptera praeputialis [5.2%], Toxocara cati [0.8%] and Toxascaris leonina [0.2%]), and 83% of cats were infected with at least one of these. The average number of species harboured was 1.4 and the average worm burden was 55.8 worms/cat. The vast majority of worms (97.6%) were cestodes, nematodes being relatively rare. Prevalence and abundance of infections were analyzed, taking into consideration four factors: year (2006 and 2007), site (urban and suburban), season (winter and summer) and sex of the host. Analyses revealed marked year effects, female host bias in some species and interactions involving combination of factors, but especially sex and season of the year. The results indicate that whilst the majority of adult feral cats in Qatar carry helminth infections, infections are variable between years and subject to annual changes that may reflect climatic and other environmental changes in the rapidly developing city of Doha and its suburban surroundings. Only two species have the potential to infect humans and both were rare among the sampled cats (A. tubaeforme and T. cati).

Use of FTA® card methodology for sampling and molecular characterization of Echinococcus granulosus sensu lato in Africa.

PubMed

Boué, Franck; El Berbri, Ikhlass; Hormaz, Vanessa; Boucher, Jean-Marc; El Mamy, Ahmed Bezeid; Traore, Abdallah; Fihri, Ouafaa Fassi; Petavy, Anne-Françoise; Dakkak, Allal; Umhang, Gérald

2017-02-01

Cystic Echinococcosis is a parasitic disease caused by the cestode Echinococcus granulosus widely distributed in Africa. Monitoring of this parasite requires access to cyst samples on intermediate hosts observed at the slaughterhouse. In order to facilitate sampling in the field and analysis, the French National Reference Laboratory for Echinococcus spp. has developed a tissue derived from DNA sampling with FTA ® card technology. The DNA samples were taken by applying the FTA ® paper on the germinal layer after opening the cysts. The sampling technique was validated using frozen cysts (n = 76) stored in the laboratory and from field samples (n = 134) taken at the slaughterhouse by veterinarian technicians during meat inspection in Morocco, Mali and Mauritania. DNA was extracted after several weeks of storage at room temperature. PCR assays were performed using primers for generic cestode (cox1) and amplified fragments were sequenced. All samples taken in the lab and 80% of field samples were capable of molecular characterization. Cyst-derived DNA from FTA ® samples can be useful for easy sampling, storage and rapid, safe and cheap shipment. The use of the FTA methodology will facilitate studies in the field to investigate the presence and genetic characterization of E. granulosus sensu lato in African countries. Copyright © 2016 Elsevier Inc. All rights reserved.

SEM and TEM study of the armed male terminal genitalia of the tapeworm Paraechinophallus japonicus (Cestoda: Bothriocephalidea).

PubMed

Levron, Céline; Poddubnaya, Larisa G; Kuchta, Roman; Freeman, Mark; Wang, Yan-Hai; Scholz, Tomás

2008-08-01

For the first time, the ultrastructure of the armed cirrus of an echinophallid cestode, Paraechinophallus japonicus (Yamaguti, 1934), has been studied with the use of scanning and transmission electron microscopy. Two sets of eversible copulatory organs (approximately 300 microm in length and approximately 130 microm in width) are present on the dorsal side of each segment near the lateral margin of the strobila. Except for the terminal portion, the cirrus is covered with large spines (up to 40 mircom long, measured from SEM photomicrographs) composed of 2 parts. The basal portion contains a lobed electron-dense outer region that gives way to a reticular meshwork of electron-dense material. The apical region of the spines, composed of a homogeneous, moderately electron-dense matrix, is slightly curved distally. Spines are covered with a cortical zone. Between the spines, the distal cytoplasm is covered with microvilli of about 1.2 microm in length. The wall of the cirrus sac, which is approximately 500 microm long and approximately 250 microm wide, is composed of 2 layers of muscles, i.e., an internal layer of circular muscles and external longitudinal muscles. Microvilli on the cirrus of P. japonicus are reported for the first time in the Cestoda, whereas the spines on the cirrus may represent a synapomorphy of bothriocephalidean cestodes of the Echinophallidae.

Tapeworm eggs in a 270 million-year-old shark coprolite.

PubMed

Dentzien-Dias, Paula C; Poinar, George; de Figueiredo, Ana Emilia Q; Pacheco, Ana Carolina L; Horn, Bruno L D; Schultz, Cesar L

2013-01-01

Remains of parasites in vertebrates are rare from the Mesozoic and Paleozoic. Once most parasites that live in - or pass through - the gastrointestinal tract of vertebrates, fossil feces (coprolites) or even intestinal contents (enterolites) can eventually preserve their remains. Here we announce the discovery of a spiral shark coprolite from the Paleozoic bearing a cluster of 93 small oval-elliptical smooth-shelled structures, interpreted as eggs of a tapeworm.The eggs were found in a thin section of an elasmobranch coprolite. Most of the eggs are filled by pyrite and some have a special polar swelling (operculum), suggesting they are non-erupted eggs. One of the eggs contains a probable developing larva. The eggs are approximately 145-155 µm in length and 88-100 µm in width and vary little in size within the cluster. The depositional and morphological features of the eggs closely resemble those of cestodes. Not only do the individual eggs have features of extant tapeworms, but their deposition all together in an elongate segment is typical to modern tapeworm eggs deposited in mature segments (proglottids). This is the earliest fossil record of tapeworm parasitism of vertebrates and establishes a timeline for the evolution of cestodes. This discovery shows that the fossil record of vertebrate intestinal parasites is much older than was hitherto known and that the interaction between tapeworms and vertebrates occurred at least since the Middle-Late Permian.

Parasitic infections of the external eye.

PubMed

Pahuja, Shivani; Puranik, Charuta; Jelliti, Bechir; Khairallah, Moncef; Sangwan, Virender S

2013-08-01

To review the published literature on parasitic infections of external eye. Published articles and case reports on parasitic infections of external eye were reviewed and relevant information was collected. Parasitic infections of the eye are rare. However, being more commonly seen in developing nations, they require active measures for screening, diagnosis, and therapy. Parasites of importance causing external ocular disease are protozoan parasites, such as Leishmania; metazoans, such as nematodes (roundworms), cestodes (tapeworms), and trematodes (flatworms); or ectoparasites, such as Phthirus pubis and Demodex.

Helminth parasites of the osprey, Pandion haliaetus, in North America

USGS Publications Warehouse

Kinsella, J.M.; Cole, Rebecca A.; Forrester, Donald J.; Roderick, Constance L.

1996-01-01

A total of 28 species of helminths (17 trematodes, 3 cestodes, 7 nematodes, and 1 acanthocephalan) was recovered from 17 ospreys (Pandion haliaetus) from the United States. Intensities of infection were low and no lesions were attributed to the parasites. Seven species appear to be specialists in ospreys, 2 species generalists in raptors, and the remainder generalists in other orders of fish-eating birds. Pandiontrema rjikovi, Diasiella diasi, and Contracaecum pandioni are reported for the first time from North America.

Metazoan Parasites of Antarctic Fishes.

PubMed

Oğuz, Mehmet Cemal; Tepe, Yahya; Belk, Mark C; Heckmann, Richard A; Aslan, Burçak; Gürgen, Meryem; Bray, Rodney A; Akgül, Ülker

2015-06-01

To date, there have been nearly 100 papers published on metazoan parasites of Antarctic fishes, but there has not yet been any compilation of a species list of fish parasites for this large geographic area. Herein, we provide a list of all documented occurrences of monogenean, cestode, digenean, acanthocephalan, nematode, and hirudinean parasites of Antarctic fishes. The list includes nearly 250 parasite species found in 142 species of host fishes. It is likely that there are more species of fish parasites, which are yet to be documented from Antarctic waters.

Diel vertical movements, and effects of infection by the cestode Schistocephalus solidus on daytime proximity of three-spined sticklebacks Gasterosteus aculeatus to the surface of a large Alaskan lake.

PubMed

Quinn, T P; Kendall, N W; Rich, H B; Chasco, B E

2012-01-01

We conducted a field study in Iliamna Lake, Alaska, to test the hypothesis that proximity of three-spined sticklebacks Gasterosteus aculeatus to the lake's surface during the daytime varies with macroparasitic cestode parasite Schistocephalus solidus infection in a manner consistent with enhanced vulnerability to avian predators. Extensive sampling in the lake and likelihood-based modeling revealed that sticklebacks displayed a diel vertical migration, being closer to the surface at night than during the evening and early morning. Additional sampling, also coupled with a likelihood-based modeling approach, showed that fish caught at the surface of the lake during the day were more often parasitized (76 vs. 65%), more heavily parasitized (26.8 vs. 22.7% of their body mass), and had larger individual parasites (0.24 vs. 0.20 g) than those caught at night. Parasite infection was related, non-linearly, to fish size, which also differed between day and night sampling at the surface. We performed statistical competitions among nested hierarchies of models that accounted for this effect of length. The most likely models indicated that fish captured during the day had greater parasite prevalence, higher parasite burdens, and larger parasites than did fish captured at night. Proximity to the surface during the day in this very clear lake would likely increase the vulnerability of sticklebacks to predation from birds, enabling completion of the parasite's lifecycle.

A Novel Terminal-Repeat Retrotransposon in Miniature (TRIM) Is Massively Expressed in Echinococcus multilocularis Stem Cells

PubMed Central

Koziol, Uriel; Radio, Santiago; Smircich, Pablo; Zarowiecki, Magdalena; Fernández, Cecilia; Brehm, Klaus

2015-01-01

Taeniid cestodes (including the human parasites Echinococcus spp. and Taenia solium) have very few mobile genetic elements (MGEs) in their genome, despite lacking a canonical PIWI pathway. The MGEs of these parasites are virtually unexplored, and nothing is known about their expression and silencing. In this work, we report the discovery of a novel family of small nonautonomous long terminal repeat retrotransposons (also known as terminal-repeat retrotransposons in miniature, TRIMs) which we have named ta-TRIM (taeniid TRIM). ta-TRIMs are only the second family of TRIM elements discovered in animals, and are likely the result of convergent reductive evolution in different taxonomic groups. These elements originated at the base of the taeniid tree and have expanded during taeniid diversification, including after the divergence of closely related species such as Echinococcus multilocularis and Echinococcus granulosus. They are massively expressed in larval stages, from a small proportion of full-length copies and from isolated terminal repeats that show transcriptional read-through into downstream regions, generating novel noncoding RNAs and transcriptional fusions to coding genes. In E. multilocularis, ta-TRIMs are specifically expressed in the germinative cells (the somatic stem cells) during asexual reproduction of metacestode larvae. This would provide a developmental mechanism for insertion of ta-TRIMs into cells that will eventually generate the adult germ line. Future studies of active and inactive ta-TRIM elements could give the first clues on MGE silencing mechanisms in cestodes. PMID:26133390

Identification of neglected cestode Taenia multiceps microRNAs by illumina sequencing and bioinformatic analysis

PubMed Central

2013-01-01

Background Worldwide, but especially in developing countries, coenurosis of sheep and other livestock is caused by Taenia multiceps larvae, and zoonotic infections occur in humans. Infections frequently lead to host death, resulting in huge socioeconomic losses. MicroRNAs (miRNAs) have important roles in the post-transcriptional regulation of a large number of animal genes by imperfectly binding target mRNAs. To date, there have been no reports of miRNAs in T. multiceps. Results In this study, we obtained 12.8 million high quality raw reads from adult T. multiceps small RNA library using Illumina sequencing technology. A total of 796 conserved miRNA families (containing 1,006 miRNAs) from 170,888 unique miRNAs were characterized using miRBase (Release 17.0). Here, we selected three conserved miRNA/miRNA* (antisense strand) duplexes at random and amplified their corresponding precursors using a PCR-based method. Furthermore, 20 candidate novel miRNA precursors were verified by genomic PCR. Among these, six corresponding T. multiceps miRNAs are considered specific for Taeniidae because no homologs were found in other species annotated in miRBase. In addition, 181,077 target sites within T. multiceps transcriptome were predicted for 20 candidate newly miRNAs. Conclusions Our large-scale investigation of miRNAs in adult T. multiceps provides a substantial platform for improving our understanding of the molecular regulation of T. multiceps and other cestodes development. PMID:23941076

Cloning and expression of phosphoenolpyruvate carboxykinase from a cestode parasite and its solubilization from inclusion bodies using l-arginine.

PubMed

Dutta, Asim K; Ramnath; Dkhar, Barilin; Tandon, Veena; Das, Bidyadhar

2016-09-01

Phosphoenolpyruvate carboxykinase is an essential regulatory enzyme of glycolysis in the cestode parasite, Raillietina echinobothrida, and is considered a potential target for anthelmintic action because of its differential activity from that of its avian host. However, due to the unavailability of its structure, the mechanism of regulation of PEPCK from R. echinobothrida (rePEPCK) and its interaction with possible modulators remain unclear. Hence, in this study, the rePEPCK gene was cloned into pGEX-4T-3 and overexpressed for its characterization. On being induced by IPTG, the recombinant rePEPCK was expressed as inclusion bodies (IBs); hence, various agents, like different inducer concentrations, temperature, time, host cell types, culture media, pH, and additives, were used to bring the protein to soluble form. Finally, a significant amount (∼46%) of rePEPCK was solubilized from IBs by adding 2M l-arginine. Near-UV circular dichroism spectra analysis indicated that l-arginine (2M) had no effect on the conformation of the protein. In this study, we have reported a yield of ∼73mg of purified rePEPCK per 1L of culture. The purified rePEPCK retained its biological activity, and Km of the enzyme for its substrate was determined and discussed. The availability of recombinant rePEPCK may help in biochemical- and biophysical-studies to explore its molecular mechanisms and regulations. Copyright © 2015 Elsevier Inc. All rights reserved.

Early intrauterine embryonic development in Khawia sinensis Hsü, 1935 (Cestoda, Caryophyllidea, Lytocestidae), an invasive tapeworm of carp (Cyprinus carpio): an ultrastructural study.

PubMed

Bruňanská, Magdaléna; Mackiewicz, John S; Młocicki, Daniel; Swiderski, Zdzisław; Nebesářová, Jana

2012-02-01

Intrauterine embryonic development in the caryophyllidean tapeworm Khawia sinensis has been investigated using transmission electron microscopy and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for glycogen. Contrary to previous light microscopy findings that reported the release of non-embryonated eggs of K. sinenesis to the external environment, the present study documents various stages of embryonation (ovoviviparity) within the intrauterine eggs of this cestode. At the initial stage of embryonic development, each fertilised oocyte is accompanied by several vitellocytes that become enclosed within the operculate, electrondense shell. Cleavage divisions result in formation of blastomeres (up to about 24 cells) of various sizes. Mitotic divisions and apparent rosette arrangment of the blastomeres, the latter atypical within the Eucestoda, are observed for the first time in the intrauterine eggs of K. sinenesis. The early embryo enclosed within the electrondense shell is surrounded by a thin membraneous layer which in some enlarged regions shows presence of nuclei. Simultaneously to multiplication and differentiation, some of the blastomeres undergo deterioration. A progressive degeneration of the vitellocytes within eggs provides nutritive reserves, including lipids, for the developing embryo. The possible significance of this atypical timing of the intrauterine embryonic development to (1) the ecology of K. sinensis and that of a recent introduction of another invasive tapeworm, the caryophyllidean Atractolytocestus huronensis Anthony, 1958 to Europe; and (2) the affiliation of caryophyllideans with other lower cestodes, are discussed.

Characteristics of the larval Echinococcus vogeli Rausch and Bernstein, 1972 in the natural intermediate host, the paca, Cuniculus paca L. (Rodentia: Dasyproctidae).

PubMed

Rausch, R L; D'Alessandro, A; Rausch, V R

1981-09-01

In Colombia, the natural intermediate host of Echinococcus vogeli Rausch and Bernstein, 1972 is the paca, Cuniculus paca L. (Rodentia: Dasyproctidae). The larval cestode develops in the liver of the host, where it usually is situated superficially, partly exposed beneath Glisson's capsule. The infective larva consists of a subspherical to asymmetrical, fluid-filled vesicle, up to 30 mm in diameter, enclosed by a thick laminated membrane. It typically contains numerous chambers, often interconnected, produced by endogenous proliferation of germinal and laminated tissue, within which brood capsules arise in an irregular pattern from the germinal layer. Invasive growth by means of exogenous proliferation, typical of infections in man, was not observed in the natural intermediate host. The development of the larval cestode is described on the basis of material from pacas, supplemented by observations on early-stage lesions in experimentally infected nutrias, Myocastor coypus (Molina) (Rodentia: Capromyidae). The tissue response is characterized for early-stage, mature (infective), and degenerating larvae in the comparatively long-lived intermediate host. In addition to previously reported differences in size and form of rostellar hooks, other morphologic characteristics are defined by which the larval stage of E. vogeli is distinguished from that of E. oligarthrus (Diesing, 1863). Pathogenesis by the larval E. vogeli in man, like that by the larval E. multilocularis Leuckart, 1863, is the consequence of atypical proliferation of vesicles attributable to parasite-host incompatibility.

The influence of habitat fragmentation on helminth communities in rodent populations from a Brazilian Mountain Atlantic Forest.

PubMed

Cardoso, T S; Simões, R O; Luque, J L F; Maldonado, A; Gentile, R

2016-07-01

The influence of habitat structure on helminth communities of three sigomdontinae rodent species (Akodon cursor, A. montensis and Oligoryzomys nigripes) was investigated in forest fragments within an agricultural landscape in south-eastern Brazil. This is a pionner study correlating the occurrence of helminth species of rodent hosts with microhabitat characteristics. Rodents were collected from 12 fragments and in a continuous conserved area. Up to 13 nematode, three cestode and two trematode species were identified, and habitat fragmentation was found to have more influence on the helminth composition of O. nigripes compared to the other two rodent species. Fragmentation appeared to limit the development of some helminths' life cycles, e.g. with some species such as Trichofreitasia lenti, Protospirura numidica, Cysticercus fasciolaris and Avellaria sp., occurring mostly in areas with less anthropic impact. However, fragmentation did not seem to affect the life cycles of other dominant helminths, such as the trematode Canaania obesa, the nematodes Stilestrongylus lanfrediae, S. eta and S. aculeata, and the cestode Rodentolepis akodontis. The helminth community structure followed a nested pattern of distribution in A. montensis and O. nigripes. Stilestrongylus lanfrediae seemed to be more associated with dense understorey, C. obesa with open canopy and dense understorey, and Guerrerostrongylus zetta with organic matter on the ground. Their presence in each area may be explained by aspects of their life cycles that take place in the external environment outside the host.

First survey of helminths in adult goats in Hunan Province, China.

PubMed

Ma, J; He, S W; Li, H; Guo, Q C; Pan, W W; Wang, X J; Zhang, J; Liu, L Z; Liu, W; Liu, Y

2014-06-01

The objective of the present survey was to reveal the prevalence of helminths in adult goats in Hunan Province, the People's Republic of China. From July 2010 through February 2013, a total of 479 goats slaughtered in local abattoirs and markets were examined for the presence of helminths using a helminthological approach. Eighty-six percent of the examined goats were infected with at least one species of helminths. In total, 15 genera of helminths were found representing 2 phyla, 3 classes, 5 orders, and 11 families. Oesophago-stomum, Ostertagia and Haemonchus were the most prevailing nematode genera, Eurytrema was the predominant trematode genus detected, whereas the infection of adult goats with cestodes was not common, with Cysticercus tenuicollis being the most common genus. The worm burdens showed obvious seasonal variation in that nematodes and cestodes were abundant in summer and winter, and the trematodes peaked in winter, which was consistent with the seasonal precipitation of Hunan Province. The geographical distribution of helminths in goats ascended with altitude. Goats in the mountainous areas were more severely infected with helminths than goats in the hilly areas, whereas infection of goats with helminths was much less in the lake areas. The present investigation highlights the high prevalence of helminths in adult goats in Hunan Province, China, which provides baseline data for assessing the effectiveness of future prevention and controlling measures against helminth infection in adult goats in this province and elsewhere.

Reaginic antibodies in dogs infected with Echinococcus granulosus

PubMed Central

Williams, J. F.; Esandi, Miguela V. Pérez

1971-01-01

Serum samples from twenty dogs infected with Echinococcus granulosus were tested for the presence of homocytotropic skin-sensitizing antibodies. Five of the twenty sera were positive in this test, while none of the sera from twenty normal dogs was positive. The antibody was thermolabile and susceptible to 2-mercaptoethanol reduction. Reaginic antibodies to cestode antigens have not been described previously in dogs, though they are frequently associated with helminth infection in other animals and may play a role in acquired resistance. ImagesFIG. 1FIG. 2 PMID:4994864

Helminth parasites of amphibians and reptiles from the Ucayali Region, Peru.

PubMed

McAllister, Chris T; Bursey, Charles R; Freed, Paul S

2010-04-01

Twenty individual amphibians representing 9 species within 6 families and 44 individual reptiles representing 15 species within 8 families from the Ucayali Region, Peru, were examined for helminths. Seven (35%) of the amphibian species and 15 (34%) of the reptiles were found to harbor at least 1 species of helminth; 5 (25%) of the amphibians and 4 (9%) of the reptiles harbored multiple infections. A cyclophyllidean cestode and 14 taxa of nematodes within 7 families were found in the herpetofauna surveyed. Thirteen new host and 6 new geographic distribution records are documented.

Helminth Fauna Associated with Three Neotropical Bat Species (Chiroptera: Mormoopidae) in Veracruz, México.

PubMed

Clarke-Crespo, Emilio; de León, Gerardo Pérez-Ponce; Montiel-Ortega, Salvador; Rubio-Godoy, Miguel

2017-08-01

Bats are recognized as potential hosts of pathogens exploiting the food chain to reach them as definitive hosts. However, very little is known about their endoparasites, especially for Neotropical bats. In this study, we assessed the helminth fauna associated with 3 insectivorous bat species roosting in the same single hot cave in central Veracruz, México: Mormoops megalophylla, Pteronotus davyi, and Pteronotus personatus. During a period of 1 yr (April 2007-2008), 135 mormoopid bats in total were collected and examined for helminths. Six parasite species representing 3 types of intestinal helminths were found: 1 cestode Vampirolepis elongatus; 2 trematodes Maxbraunium tubiporum and Ochoterenatrema labda; and 3 nematodes Linustrongylus pteronoti, Molineidae gen. sp., and Capillaria sp. Overall, trematodes were the most abundant parasite group (72.4%), followed by nematodes (20.7%) and cestodes (6.9%). Species-accumulation curves suggest that the worms collected (n = 1,331) from these 6 parasite species comprise the helminth fauna associated with the 3 bat populations studied. The only species shared by the 3 bat species was Capillaria sp. Most (5/6) of the helminth species recorded use Lepidoptera and Diptera as intermediate hosts; therefore, diet is likely the main source of infection. Although insectivorous bats are considered dietary generalist species, the differences found in helminth diversity in these sympatric populations of closely related bat species, suggest that diet partitioning occurs in mormoopid bat communities. Helminths tend to exploit the food chain to reach their final hosts; therefore, studying these parasites can provide useful information to further understand the biology of bats.

Coproantigens in taeniasis and echinococcosis.

PubMed

Allan, James C; Craig, Philip S

2006-01-01

The application of modern immunodiagnostic or molecular diagnostic techniques has improved the diagnosis of the taeniid cestode infections, echinococcosis and taeniasis. One particularly promising approach is the detection of parasite-specific antigens in faeces (coproantigens). This approach has been applied to both Echinoccocus and Taenia species and it has gained increasingly widespread use. Taeniid coproantigen tests are based on either monoclonal or polyclonal antibodies raised against adult tapeworm antigens. These tests have the following common characteristics; they are largely genus-specific, specificity is high (>95%), parasite antigen can be detected in faeces weeks prior to patency, levels of coproantigen are independent of egg output, coproantigen is stable for days at a range of temperatures (-80 degrees C to 35 degrees C), for several months in formalin-fixed faecal samples, and coproantigen levels drop rapidly (1-5 days) following successful treatment. In the genus Taenia, most work has been done on Taenia solium and coproantigen tests have reliably detected many more tapeworm carriers than microscopy. For Echinococcus species, there is a broad positive correlation between test sensitivity and worm burden with a reliable threshold level for the test of >50 worms. Characterisation of taeniid coproantigens in order to further improve the tests is ongoing. Studies indicate taeniid coproantigens to include high molecular weight (>150 kDa), heavily glycosylated molecules with carbohydrate moieties contributing substantially to the levels of antigen detected in faeces. Application of the existing coproantigen tests in epidemiological and control programmes for Echinococcus and Taenia species infection has begun to contribute to an improved understanding of transmission and of surveillance of these important zoonotic cestodes.

Helminth communities of two species of piscivorous birds, Ardea alba (Linnaeus) and Nyctanassa violacea (Gmelin) (Ciconiiformes: Ardeidae), in two coastal lagoons from Guerrero state, Mexico.

PubMed

Violante-González, Juan; Monks, Scott; Gil-Guerrero, Salvador; Rojas-Herrera, Agustín A; Flores-Rodríguez, Pedro

2012-07-01

The composition and species richness in helminth communities of two species of heron, Ardea alba and Nyctanassa violacea, in two coastal lagoons from Guerrero, Mexico were examined. Nineteen species of helminth (7,804 individuals) were identified in 43 adult birds: 15 digeneans, 1 acanthocephalan, 1 cestode, and 2 nematodes. Eight species co-occurred in herons of both species and lagoons. The prevalence values of seven species and the mean abundance of five species varied significantly between species of birds and between lagoons. The heterophyid, Ascocotyle (Phagicola) longa, was the helminth numerically dominant in the helminth community of A. alba in both lagoons, while the cestode, Parvitaenia cochlearii, dominated the community of N. violacea. At the component community level, species richness varied significantly: 10 species in A. alba from Coyuca to 16 in N. violacea (Tres Palos). All of the birds examined were infected with helminth parasites: three to seven species per host in A. alba from Coyuca, and two to eight species in A. alba and N. violacea from Tres Palos. The results indicate that even though species composition was similar between both species of heron, the structure of their communities was not the same. Differences in the feeding behavior of the birds (day/night habits), as well as local differences in the abundance of species of fish, and infection levels of helminths in each lagoon are suggested as being responsible for the variations registered in the structure of the helminth communities.

A Novel Terminal-Repeat Retrotransposon in Miniature (TRIM) Is Massively Expressed in Echinococcus multilocularis Stem Cells.

PubMed

Koziol, Uriel; Radio, Santiago; Smircich, Pablo; Zarowiecki, Magdalena; Fernández, Cecilia; Brehm, Klaus

2015-07-01

Taeniid cestodes (including the human parasites Echinococcus spp. and Taenia solium) have very few mobile genetic elements (MGEs) in their genome, despite lacking a canonical PIWI pathway. The MGEs of these parasites are virtually unexplored, and nothing is known about their expression and silencing. In this work, we report the discovery of a novel family of small nonautonomous long terminal repeat retrotransposons (also known as terminal-repeat retrotransposons in miniature, TRIMs) which we have named ta-TRIM (taeniid TRIM). ta-TRIMs are only the second family of TRIM elements discovered in animals, and are likely the result of convergent reductive evolution in different taxonomic groups. These elements originated at the base of the taeniid tree and have expanded during taeniid diversification, including after the divergence of closely related species such as Echinococcus multilocularis and Echinococcus granulosus. They are massively expressed in larval stages, from a small proportion of full-length copies and from isolated terminal repeats that show transcriptional read-through into downstream regions, generating novel noncoding RNAs and transcriptional fusions to coding genes. In E. multilocularis, ta-TRIMs are specifically expressed in the germinative cells (the somatic stem cells) during asexual reproduction of metacestode larvae. This would provide a developmental mechanism for insertion of ta-TRIMs into cells that will eventually generate the adult germ line. Future studies of active and inactive ta-TRIM elements could give the first clues on MGE silencing mechanisms in cestodes. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Comparative Proteomic Analysis of Hymenolepis diminuta Cysticercoid and Adult Stages

PubMed Central

Sulima, Anna; Savijoki, Kirsi; Bień, Justyna; Näreaho, Anu; Sałamatin, Rusłan; Conn, David Bruce; Młocicki, Daniel

2018-01-01

Cestodiases are common parasitic diseases of animals and humans. As cestodes have complex lifecycles, hexacanth larvae, metacestodes (including cysticercoids), and adults produce proteins allowing them to establish invasion and to survive in the hostile environment of the host. Hymenolepis diminuta is the most commonly used model cestode in experimental parasitology. The aims of the present study were to perform a comparative proteomic analysis of two consecutive developmental stages of H. diminuta (cysticercoid and adult) and to distinguish proteins which might be characteristic for each of the stages from those shared by both stages. Somatic proteins of H. diminuta were isolated from 6-week-old cysticercoids and adult tapeworms. Cysticercoids were obtained from experimentally infected beetles, Tenebrio molitor, whereas adult worms were collected from experimentally infected rats. Proteins were separated by GeLC-MS/MS (one dimensional gel electrophoresis coupled with liquid chromatography and tandem mass spectrometry). Additionally protein samples were digested in-liquid and identified by LC-MS/MS. The identified proteins were classified according to molecular function, cellular components and biological processes. Our study showed a number of differences and similarities in the protein profiles of cysticercoids and adults; 233 cysticercoid and 182 adult proteins were identified. From these proteins, 131 were present only in the cysticercoid and 80 only in the adult stage samples. Both developmental stages shared 102 proteins; among which six represented immunomodulators and one is a potential drug target. In-liquid digestion and LC-MS/MS complemented and confirmed some of the GeLC-MS/MS identifications. Possible roles and functions of proteins identified with both proteomic approaches are discussed. PMID:29379475

Ultrastructure of the anterior organ and posterior funnel-shaped canal of Gyrocotyle urna Wagener, 1852 (Cestoda: Gyrocotylidea).

PubMed

Poddubnaya, Larisa G; Kuchta, Roman; Bristow, Glenn A; Scholz, Tomas

2015-05-22

Using scanning and transmission electron microscopy, ultrastructure of the anterior organ and posterior funnel-shaped canal of Gyrocotyle urna Wagener, 1852 (Cestoda: Gyrocotylidea) from ratfish, Chimaera monstrosa (Holocephali), was studied for the first time. The proper anterior organ is localised at a short distance (about 170 µm) from an apical pore surrounded by a receptor field, whereas its distal end is marked by a muscular sphincter. The tegumental surface of this organ is covered with short filitriches of irregular length; large area of muscle layers traverse beneath the tegumental layer. The funnel-shaped canal of G. urna (2.5-3.0 mm long) is a specialised, muscular part of the posterior attachment organ; it opens on the rounded elevation on the dorsal body surface. The tegumental layer bears conical sclerite-like structures (up to 1.5 µm long). It produces electron-dense bodies that are transported into a canal lumen and surrounded thick muscle area mixed with numerous nerve fibres. The present ultrastructural study of G. urna indicates that gyrocotylideans share some ultrastructural characters of the anterior organ with spathebothriidean cestodes with a single anterior attachment sucker-like organ. In contrast, the unique posterior rosette attachment organ with funnel-shaped canal of the Gyrocotylidea resembles the haptor of polyopisthocotylean monogeneans in its position at the posterior end of the body and presumed origin. The above-mentioned features add more clarity to support the basal position of the Gyrocotylidea Poche, 1926 among cestodes. In addition, they also indicate a possible relationship of gyrocotylidean ancestors with monogeneans.

Carotenoid-based bill colour is an integrative signal of multiple parasite infection in blackbird

NASA Astrophysics Data System (ADS)

Biard, Clotilde; Saulnier, Nicolas; Gaillard, Maria; Moreau, Jérôme

2010-11-01

In the study of parasite-mediated sexual selection, there has been controversial evidence for the prediction that brighter males should have fewer parasites. Most of these studies have focused on one parasite species. Our aim was to investigate the expression of carotenoid-based coloured signals in relation to patterns of multiple parasite infections, to determine whether colour reflects parasite load of all parasite species, or whether different relationships might be found when looking at each parasite species independently. We investigated the relationship between bill colour, body mass and plasma carotenoids and parasite load (feather chewing lice, blood parasite Plasmodium sp., intestinal parasites cestodes and coccidia) in the blackbird ( Turdus merula). Bill colour on its own appeared to be a poor predictor of parasite load when investigating its relationships with individual parasite species. Variation in parasite intensities at the community level was summarised using principal component analysis to derive synthetic indexes of relative parasite species abundance and absolute parasite load. The relative abundance of parasite species was strongly related to bill colour, plasma carotenoid levels and body mass: birds with relatively more cestodes and chewing lice and relatively less Plasmodium and coccidia had a more colourful bill, circulated more carotenoids and were heavier. These results suggest that bill colour more accurately reflects the relative intensities of parasite infection, rather than one-by-one relationships with parasites or absolute parasite burden. Investigating patterns of multiple parasite infection would thus improve our understanding of the information conveyed by coloured signals on parasite load.

Molecular phylogeny of Cyclophyllidea (Cestoda: Eucestoda): an in-silico analysis based on mtCOI gene.

PubMed

Sharma, Sunil; Lyngdoh, Damanbha; Roy, Bishnupada; Tandon, Veena

2016-09-01

Order Cyclophyllidea (of cestode platyhelminths) has a rich diversity of parasites and includes many families and species that are known to cause serious medical condition in humans and domestic and wild animals. Despite various attempts to resolve phylogenetic relationships at the inter-family level, uncertainty remains. In order to add resolution to the existing phylogeny of the order, we generated partial mtCO1 sequences for some commonly occurring cyclophyllidean cestodes and combined them with available sequences from GenBank. Phylogeny was inferred taking a total 83 representative species spanning 8 families using Bayesian analysis. The phylogenetic tree revealed Dilepididae as the most basal taxon and showed early divergence in the phylogenetic tree. Paruterinidae, Taeniidae and Anoplocephalidae showed non-monophyletic assemblage; our result suggests that the family Paruterinidae may represent a polyphyletic group. The diverse family Taeniidae appeared in two separate clades; while one of them included all the members of the genus Echinococcus and also Versteria, the representatives of the genera Taenia and Hydatigera clubbed in the other clade. A close affinity of Dipylidiidae with Taenia and Hydatigera was seen, whereas existence of a close relationship between Mesocestoididae and Echinococcus (of Taeniidae) is also demonstrated. The crown group comprised the families Anoplocephalidae, Davaineidae, Hymenolepididae and Mesocestoididae, and also all species of the genus Echinococcus and Versteria mustelae; monophyly of these families (excepting Anolplocephalidae) and the genus Echinococcus as well as its sister-taxon relation with V. mustelae is also confirmed. Furthermore, non-monophyly of Anoplocephalidae is suggested to be correlated with divergence in the host selection.

Parasites of domestic and wild animals in South Africa. XLII. Helminths of sheep on four farms in the Eastern Cape Province.

PubMed

Horak, I G

2003-09-01

At monthly intervals for periods ranging from 9 to 25 consecutive months between three and four Merino yearling-sheep and two Merino lambs on three farms in Eastern Cape Thornveld, and two Dorper yearling-sheep on a farm in Valley Bushveld were slaughtered and examined for helminths. The Merino sheep were infected with 15 nematode species, of which Haemonchus contortus, Nematodirus spathiger and Trichostrongylus spp. were the most numerous, and with four cestode species. The Dorper sheep were infected with 17 nematode species, of which Trichostrongylus rugafus and N. spathiger were the most numerous, and with two cestode species. Haemonchus contortus was most numerous in older sheep during the summer months and exhibited no tendency to over-winter as arrested fourth stage larvae. The largest numbers of N. spathiger were present in sheep on the most coastally located of the farms during autumn and winter; on a farm further inland during spring; and on an inland farm in Valley Bushveld during spring and summer. As Merino lambs progressed from birth to 9 months of age a larger proportion of their dwindling burdens of N. spathiger was present as fourth stage larvae. Dorper sheep in Valley Bushveld harboured most Teladorsagia circumcincta in May and from October to January. Trichostrongylus rugatus was most numerous in Merino sheep on one of the Thornveld farms during September, whereas all Trichostrongylus spp., including T. rugatus, were most numerous in Dorper sheep on the Valley Bushveld farm during January.

Intestinal Helminths Recovered from Humans in Xieng Khouang Province, Lao PDR with a Particular Note on Haplorchis pumilio Infection.

PubMed

Chai, Jong-Yil; Sohn, Woon-Mok; Jung, Bong-Kwang; Yong, Tai-Soon; Eom, Keeseon S; Min, Duk-Young; Insisiengmay, Bounnaloth; Insisiengmay, Sithat; Phommasack, Bounlay; Rim, Han-Jong

2015-08-01

A survey of intestinal helminths was undertaken in riparian people in Xieng Khouang Province, Lao PDR. Fecal specimens were collected from 643 people (289 males and 354 females) residing in 4 districts (Nonghet, Kham, Phoukout, and Pek) and were examined by the Kato-Katz technique. The overall helminth egg positive rate was 41.2%, and hookworms revealed the highest prevalence (32.7%) followed by Trichuris trichiura (7.3%) and Ascaris lumbricoides (5.6%). The positive rate for small trematode eggs (STE), which may include Opisthorchis viverrini, heterophyids, and lecithodendriids, was 4.4%. For recovery of adult helminths, 12 STE or nematode/cestode egg-positive people were treated with 40 mg/kg praziquantel and 15 mg/kg pyrantel pamoate, and then purged. Mixed infections with 2 Haplorchis species (H. pumilio and H. taichui), Centrocestus formosanus, Opisthorchis viverrini, a species of cestode (Taenia saginata), and several species of nematodes including hookworms and Enterobius vermicularis were detected. The worm load for trematodes was the highest for H. pumilio with an average of 283.5 specimens per infected person followed by C. formosanus, H. taichui, and O. viverrini. The worm load for nematodes was the highest for hookworms (21.5/infected case) followed by E. vermicularis (3.2/infected case). The results revealed that the surveyed areas of Xieng Khouang Province, Lao PDR are endemic areas of various species of intestinal helminths. The STE found in the surveyed population were verified to be those of heterophyids, particularly H. pumilio.

Lead concentrations in some organs of the rat Meriones libycus and its parasite Hymenolepis diminuta from Riyadh City, KSA.

PubMed

Al-Qureishy, Saleh

2008-08-01

In the present study, the tape worm Hymenolepis diminuta was chosen to estimate lead bioaccumulation in an urban area highly polluted with lead (the industrial area) and another less polluted one (Al-Karj road) at Riyadh City, K.S.A. Lead concentrations were found 38 to be 32 and 15 times in the parasite (H. diminuta) than in the intestine, liver and kidney of the host (Meriones libycus). Thus, the proposed model of cestode parasite-rat as bio-indicator of lead pollution seems to be promising in the terrestrial habitat.

Dipylidium caninum infection

PubMed Central

Cabello, Raúl Romero; Ruiz, Aurora Candil; Feregrino, Raul Romero; Romero, Leticia Calderón; Feregrino, Rodrigo Romero; Zavala, Jorge Tay

2011-01-01

Dipylidium caninum is a cestode that requires from the participation of an arthropod in its life cycle. This parasitosis occurs in dogs and cats, and occasionally in human beings. Human cases of D caninum infection have been reported in Europe, Philippines, China, Japan, Latin America and the United States; mostly children, one third of them being infants under 6 months old. The diagnosis of this disease is done by the parasitological study of the feces, observing the characteristics of the gravid proglottids. The treatment is performed by administering broad-spectrum anthelmintics. The authors report a case of a rare infection in a Mexican child. PMID:22674592

Diagnosis and therapeutic management of Dipylidium caninum in dogs: a case report.

PubMed

Saini, Vijesh Kumar; Gupta, Snehil; Kasondra, Arjun; Rakesh, R L; Latchumikanthan, A

2016-12-01

The present study is related to Dipylidium caninum infection in dogs. Three dogs about 1 year of age with the history of scooting behaviour and passing diarrhoeic stool containing white specks were presented before the clinicians. Physical examination of dogs revealed flea infestation and faecal examination revealed the presence of gravid segments, which were confirmed microscopically to be of cestode, D. caninum. Dogs were treated with Praziquantel@5 mg/kg body wt. orally. Dogs showed marked recovery post treatment. On re-examination after a week, faeces were found negative for any parasitic eggs/gravid segments.

Dipylidium caninum infection.

PubMed

Cabello, Raúl Romero; Ruiz, Aurora Candil; Feregrino, Raul Romero; Romero, Leticia Calderón; Feregrino, Rodrigo Romero; Zavala, Jorge Tay

2011-11-15

Dipylidium caninum is a cestode that requires from the participation of an arthropod in its life cycle. This parasitosis occurs in dogs and cats, and occasionally in human beings. Human cases of D caninum infection have been reported in Europe, Philippines, China, Japan, Latin America and the United States; mostly children, one third of them being infants under 6 months old. The diagnosis of this disease is done by the parasitological study of the feces, observing the characteristics of the gravid proglottids. The treatment is performed by administering broad-spectrum anthelmintics. The authors report a case of a rare infection in a Mexican child.

Echinococcus granulosus and other intestinal helminths: current status of prevalence and management in rural dogs of eastern Australia.

PubMed

Jenkins, D J; Lievaart, J J; Boufana, B; Lett, W S; Bradshaw, H; Armua-Fernandez, M T

2014-08-01

Ascertain the prevalence of intestinal helminths in rural dogs from eastern Australia and Tasmania. Identify farm management practices contributing to the perpetuation and transmission of Echinococcus granulosus. Helminth infection in dogs was determined microscopically through faecal flotation. Infection with E. granulosus was determined via faecal antigen-capture ELISA and coproPCR. Taeniid eggs were identified using molecular methods. Data on dog management and owner understanding of hydatid disease were collected via questionnaire. Faeces were collected from 1425 Australian rural dogs (1119 mainland; 306 Tasmania). Eggs of hookworms were most prevalent, up to 40.2%, followed by whipworms (Trichuris vulpis), up to 21.2%. Roundworms (Toxocara canis and Toxascaris leonine) were least common, up to 6.1%. Taeniid eggs were found in 11 dogs (5 Taenia pisiformis; 2 T. serialis; 4 T. hydatigena); 2 of the T. hydatigena-infected dogs were also E. granulosus coproantigen-positive. Of the 45 dogs found to be E. granulosus coproantigen-positive, 24 were in Tasmania, 16 in NSW, 3 in Victoria and 2 in Queensland. Three Tasmanian coproantigen ELISA-positive dogs were also coproPCR-positive. The most common dog ration was commercial dry food, but half the owners fed raw meat to their dogs and some fed offal of lambs (8.9%) or mutton (7.8%). More than half (69%) of owners weighed their dogs before deworming. Few dewormed their dogs often enough to ensure they remained cestode-free and owners hunting wildlife usually left carcases where they were shot. E. granulosus is still present in Australian rural dogs, including Tasmania, but at low levels. Owner behaviour perpetuates transmission of cestodes. © 2014 Australian Veterinary Association.

Developmental expression of high molecular weight tropomyosin isoforms in Mesocestoides corti.

PubMed

Koziol, Uriel; Costábile, Alicia; Domínguez, María Fernanda; Iriarte, Andrés; Alvite, Gabriela; Kun, Alejandra; Castillo, Estela

2011-02-01

Tropomyosins are a family of actin-binding proteins with diverse roles in actin filament function. One of the best characterized roles is the regulation of muscle contraction. Tropomyosin isoforms can be generated from different genes, and from alternative promoters and alternative splicing from the same gene. In this work, we have isolated sequences for tropomyosin isoforms from the cestode Mesocestoides corti, and searched for tropomyosin genes and isoforms in other flatworms. Two genes are conserved in the cestodes M. corti and Echinococcus multilocularis, and in the trematode Schistosoma mansoni. Both genes have the same structure, and each gene gives rise to at least two different isoforms, a high molecular weight (HMW) and a low molecular weight (LMW) one. Because most exons are duplicated and spliced in a mutually exclusive fashion, isoforms from one gene only share one exon and are highly divergent. The gene duplication preceded the divergence of neodermatans and the planarian Schmidtea mediterranea. Further duplications occurred in Schmidtea, coupled to the selective loss of duplicated exons, resulting in genes that only code for HMW or LMW isoforms. A polyclonal antibody raised against a HMW tropomyosin from Echinococcus granulosus was demonstrated to specifically recognize HMW tropomyosin isoforms of M. corti, and used to study their expression during segmentation. HMW tropomyosins are expressed in muscle layers, with very low or absent levels in other tissues. No expression of HMW tropomyosins is present in early or late genital primordia, and expression only begins once muscle fibers develop in the genital ducts. Therefore, HMW tropomyosins are markers for the development of muscles during the final differentiation of genital primordia. Copyright © 2010 Elsevier B.V. All rights reserved.

Pyruvate dehydrogenase complexes from the equine nematode, Parascaris equorum, and the canine cestode, Dipylidium caninum, helminths exhibiting anaerobic mitochondrial metabolism.

PubMed

Diaz, F; Komuniecki, R W

1994-10-01

The pyruvate dehydrogenase complex (PDC) has been purified to apparent homogeneity from 2 parasitic helminths exhibiting anaerobic mitochondrial metabolism, the equine nematode, Parascaris equorum, and the canine cestode, Dipylidium caninum. The P. equorum PDC yielded 7 major bands when separated by SDS-PAGE. The bands of 72, 55-53.5, 41 and 36 kDa corresponded to E2, E3, E1 alpha and E1 beta, respectively. The complex also contained additional unidentified proteins of 43 and 45 kDa. Incubation of the complex with [2-14C]pyruvate resulted in the acetylation of only E2. These results suggest that the P. equorum PDC lacks protein X and exhibits an altered subunit composition, as has been described previously for the PDC of the related nematode, Ascaris suum. In contrast, the D. caninum PDC yielded only four major bands after SDS-PAGE of 59, 58, 39 and 34 kDa, which corresponded to E3, E2, E1 alpha and E1 beta, respectively. Incubation of the D. caninum complex with [2-14C]pyruvate resulted in the acetylation of E2 and a second protein which comigrated with E3, suggesting that the D. caninum complex contained protein X and had a subunit composition similar to PDCs from other eukaryotic organisms. Both helminth complexes appeared less sensitive to inhibition by elevated NADH/NAD+ ratios than complexes isolated from aerobic organisms, as would be predicted for PDCs from organisms exploiting microaerobic habitats. These results suggest that although these helminths have similar anaerobic mitochondrial pathways, they contain significantly different PDCs.

A new monozoic tapeworm, Lobulovarium longiovatum n. g., n. sp. (Cestoda: Caryophyllidea), from barbs Puntius spp. (Teleostei: Cyprinidae) in the Indomalayan region.

PubMed

Oros, Mikuláš; Ash, Anirban; Brabec, Jan; Kar, Pradip Kumar; Scholz, Tomáš

2012-09-01

A new caryophyllidean cestode is described from barbs Puntius spp. (Cypriniformes: Cyprinidae), with P. sophore (Hamilton) as its type-host, in the Ganges and Brahmaputra river basins in India and Bangladesh, and a new genus, Lobulovarium n. g., is proposed to accommodate it. The genus belongs to the Lytocestidae because its vitelline follicles are situated in the cortex. It is typified by: (i) a peculiar ovary, which is roughly H-shaped, but with asymmetrical, irregular lobes on its ventral and dorsal sides; (ii) an extensive vitellarium formed by numerous vitelline follicles scattered throughout the cortex; (iii) a long, conical postovarian part of the body with numerous vitelline follicles; (iv) a broadly digitate scolex with a slightly protrusible central cone; (v) a single gonopore (male and female genital ducts open via a single pore and a common genital atrium is absent); and (vi) a small number of testes (< 60). Molecular data (partial sequences of the lsrDNA) indicate that Lobulovarium longiovatum n. sp. belongs among the most basal caryophyllidean cestodes, being unrelated to species from siluriform catfishes in the Indomalayan region. Paracaryophyllaeus osteobramensis (Gupta & Sinha, 1984) Hafeezullah, 1993 (syn. Pliovitellaria osteobramensis Gupta & Sinha, 1984) from another cyprinid fish, Osteobrama cotio (Hamilton), in Uttar Pradesh, India, is tentatively transferred to Lobulovarium as L. osteobramense (Gupta & Sinha, 1984) n. comb. It differs from L. longiovatum by having much smaller eggs (length <50 μm versus >90 μm in L. longiovatum), which are spherical (length/width ratio 1:1 versus 2.5-3:1 in the new species), and the presence of vitelline follicles alongside the ovarian lobes (almost completely absent in L. longiovatum).

Environmental parasitology: Parasites as accumulation bioindicators in the marine environment

NASA Astrophysics Data System (ADS)

Nachev, Milen; Sures, Bernd

2016-07-01

Parasites can be used as effective monitoring tools in environmental impact studies as they are able to accumulate certain pollutants (e.g. metals) at levels much higher than those of their ambient environment and of free-living sentinels. Thus, they provide valuable information not only about the chemical conditions of their and their hosts' environment but also deliver insights into the biological availability of allochthonous substances. While a large number of different freshwater parasites (mainly acanthocephalans and cestodes) were investigated in terms of pollutant bioaccumulation, studies based on marine host-parasites systems remain scarce. However, available data show that different marine parasite taxa such as nematodes, cestodes and acanthocephalans exhibit also an excellent metal accumulation capacity. The biological availability of metals and their uptake routes in marine biota and parasites differ from those of freshwater organisms. We assume that a large part of metals and other pollutants are also taken up via the digestive system of the host. Therefore, in addition to environmental conditions the physiology of the host also plays an important role for the accumulation process. Additionally, we highlight some advantages in using parasites as accumulation indicators in marine ecosystems. As parasites occur ubiquitously in marine food webs, the monitoring of metals in their tissues can deliver information about the spatial and trophic distribution of pollutants. Accordingly, parasites as indicators offer an ecological assessment on a broader scale, in contrast to established free-living marine indicators, which are mostly benthic invertebrates and therefore limited in habitat distribution. Globally distributed parasite taxa, which are highly abundant in a large number of host species, are suggested as worldwide applicable sentinels.

[Role of helminth antigens in the abnormal mitosis of bone marrow cells in laboratory animals].

PubMed

Sivkova, T N; Tatarnikova, N A; Berezhko, V K; Benediktov, I I

2013-01-01

The intraabdominal administration of somatic extracts of the cestodes Hydatigera taeniaformis Batsch 1786, Lamarck, 1816 and Diphyllobothrium latum Linnaeus, 1758 and the nematodes Anisakis simplex larva Rudolphi 1809, Toxocara canis Railliet et Henry, 1912 in albino mice proved that these helminths had a karyopathic effect on the bone marrow cells of the animals. The antigenic composition of these extracts was investigated using the agar gel immunodiffusion test. The antigenic composition of the parasites was ascertained to affect their karyopathic properties. The amount of antigens and their foreignness caused a marked karyopathic effect on the bone marrow cells of laboratory animals during intraabdominal administration.

Hydatid cyst of urinary bladder associated with pregnancy:a case report.

PubMed

Kanagal, Deepa V; Hanumanalu, Lokeshchandra C

2010-07-01

Echinococcosis or hydatid disease which is caused by Echinococcus group of cestodes is very rare in pregnancy. While liver and lungs are commonly involved, other sites can be rarely affected. The management of hydatid disease in pregnancy is challenging in view of varied presentation and manifestation. We report a case of hydatid cyst arising from the bladder associated with pregnancy and presenting with abdominal pain. The cyst was surgically removed and the bladder wash was given with povidone-iodine. The postoperative recovery was uneventful with ongoing pregnancy. This is to our knowledge, the first case of hydatid cyst arising from the bladder associated with pregnancy to be reported.

[Parasite fauna of the European river lamprey Lampetra fluviatilis (L.) from Lake Onega].

PubMed

Evseeva, N V

2007-01-01

Data on the parasite fauna of the adult European river lamprey Lampetra fluviatilis (L.) from Lake Onega are reported. Ten parasite species are found, including trematodes Diplostomum petromyzifluviatilis and D. spathaceum (metacercariae), cestode Proteocephalus longicollis, nematodes Cucullanus truttae and Raphidascaris acus, acanthocephalan Echinorhynchus salmonis, ectoparasitic infusoria Chilodonella hexastica, Trichodina tenuidens, and Trichodinella epizootica, and fungus Saprolegnia parasitica. Three species are found to be dominate, namely D. petromyzifluviatilis, Cucullanus truttae, and P. longicollis. Comparative analysis of the parasite faunas of the lampreys from other basins is carried out. Some similarity in the parasite faunas of lampreys and salmonids is discovered.

Acanthocephaliasis

USGS Publications Warehouse

Cole, Rebecca A.

1999-01-01

The phylum Acanthocephala contains parasitic worms referred to as thorny-headed worms because both the larval and adult parasites have a retractable proboscis or a tubular structure at the head, which has sharp, recurved hooks or spines. Much like the cestodes or tapeworms, they lack digestive tracts and absorb nutrients from the bird’s intestinal canal. This may weaken the bird and may make it more susceptible to other diseases and to predation.Adult acanthocephalans are found in a variety of bird species and in other vertebrates. More than 50 species of acanthocephalans have been reported in waterfowl, but reevaluations of acanthocephalan taxonomy are resulting in revised speciation. Nevertheless, numerous species within the phylum are found in birds.

The helminth community of the skink Chalcides sexlineatus from Gran Canaria (Canary Islands).

PubMed

Roca, V; Carretero, M A; Jorge, F; Perera, A; Ferrero, A; Rodríguez-Reina, S

2012-06-01

A survey of the gastrointestinal helminth communities of a population of Chalcides sexlineatus Steindachner, a small skink endemic to Gran Canaria island (Canary Archipelago, Spain), was conducted to determine the prevalence, abundance and species diversity of intestinal parasites in these reptiles. Only three parasite species were found, one cestode, Oochoristica agamae Baylis, 1919 and two nematodes, Parapharyngodon micipsae (Seurat, 1917) and Pharyngodonidae gen. sp. Helminth infracommunities of C. sexlineatus showed low values of abundance and species richness and diversity, being more similar to the helminth community of Tarentola boettgeri boettgeri (Steindachner) rather than those of Gallotia stehlini (Schenkel), both syntopic with the sampled host.

Invaded invaders: Infection of invasive Brown Treesnakes on Guam by an exotic larval cestode with a life cycle comprised of non-native hosts

USGS Publications Warehouse

Holldorf, Elden T; Siers, Shane R.; Richmond, Jonathan Q.; Klug, Page E.; Reed, Robert

2015-01-01

We discovered that B. irregularis inhabiting a small area of forested habitat in a freshwater watershed on Guam are often infected by a novel parasite of Asian origin. While further work is needed, this species of Spirometra, itself a non-native species, likely depends on a suite of recently introduced hosts from different parts of the world to complete the life cycle. This baseline study provides little evidence of any effects on host fitness, but additional data are needed to more thoroughly explore the consequences of infection in this invasive snake population.

Identification of an expressed gene in Dipylidium caninum.

PubMed

Miranda, Rodrigo R C; Costa-Júnior, Livio M; Campos, Artur K; Santos, Hudson A; Rabelo, Elida M L

2004-10-01

Recombinant DNA studies have been focused on developing vaccines to different cestodes. But few studies involving Dipylidium caninum molecular biology and genes have been done. Only partial sequences of mitochondrial DNA and ribosomal RNA gene are available in databases. Any molecular work with this parasite, including epidemiology, study of drug-resistant strains, and vaccine development, is hampered by the lack of knowledge of its genome. Thus, the knowledge of specific genes of different developmental stages of D. caninum is crucial to locate potential targets to be used as candidates to develop a vaccine and/or new drugs against this parasite. Here we report, for the first time, the sequencing of a fragment of a D. caninum expressed gene.

Rodentolepis straminea (Cestoda: Hymenolepididae) in an urban population of Apodemus sylvaticus in the UK.

PubMed

Rushworth, R L; Boufana, B; Hall, J L; Brannan, V; Mastin, A; Birtles, R J; Craig, P S; Rogan, M T

2016-07-01

The presence of the cyclophyllidean cestode Rodentolepis straminea (Cestoda: Hymenolepididae), was confirmed by molecular DNA analysis from a wood mouse (Apodemus sylvaticus) population inhabiting urban woodland in Salford, Greater Manchester (UK) with a prevalence of 27.8%. It would appear that the only previously published record of this species in A. sylvaticus in the British Isles is that from south-west Ireland, where 24% of the wood mice examined were infected with R. straminea. This species has been recorded in studies on A. sylvaticus in continental Europe. The current report represents a new record for R. straminea on mainland Britain and a first study of helminth parasites in an urban wood mouse population.

[Helminth findings in indigenous raccoon dogs Nyctereutes procyonoides (Gray, 1843)].

PubMed

Thiess, A; Schuster, R; Nöckler, K; Mix, H

2001-01-01

Internal organs of 74 racoon dogs originating from the eastern districts of the Federal Land Brandenburg were subjected to a complete helminthological dissection. In addition, samples of diaphragma muscles from 46 further animals were examined for Trichinella larvae. Altogether 3 trematode- (Alaria alata, Isthmiophora melis, Metorchis bilis), 3 cestode- (Mesocestoides sp., Echinococcus multilocularis, Taenia polyacantha) and 7 nematode species (Capillaria aerophila, C. plica, Trichinella spiralis, Uncinaria stenocephala, Molineus patens, Crenosoma vulpis, Toxocara canis) could be identified. Thereby, the racoon dog has a comparable helminth spectrum as well known in red foxes. Differences in the frequency of the occurrence of helminths in both hosts can be explained by different food preferences.

Parasites of the African clawed frog, Xenopus laevis, in southern California, U.S.A

USGS Publications Warehouse

Kuperman, Boris I.; Matey, Victoria E.; Fisher, Richard N.; Ervin, Edward L.; Warburton, Manna L.; Bakhireva, Ludmila; Lehman, Cynthia A.

2004-01-01

A total of 230 feral African clawed frogs, Xenopus laevis, from 3 localities in southern California were examined for parasites. The following species were found: 3 species of Protozoa, Nyctotherussp., Balantidium xenopodis, Protoopalina xenopodus; 2 species of Monogenea, Protopolystoma xenopodis, Gyrdicotylus gallieni; 1 species of Digenea, Clinostomum sp. (as metacercariae); 1 species of Cestoda, Cephalochlamys namaquensis; 2 species of Nematoda, Contracaecum sp. (as larvae), Eustrongylides sp. (as larvae); and 1 species of Acanthocephala, Acanthocephalus sp. (as cystacanth). Of these, the protozoans P. xenopodus and B. xenopodis, both monogeneans, and the cestode have an African origin. Contracaecum sp., Eustrongylides sp., and Acanthocephalus sp. have not been previously reported from X. laevis.

Cysticercosis of the fallopian tube: histology and microanalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abraham, J.L.; Spore, W.W.; Benirschke, K.

1982-07-01

The authors identified a degenerated, focally calcified cestode larva (cysticercus) in the fallopian tube of a 50-year-old woman with endometriosis. The physiologic reaction to the larva was minimal, with some focal granulomatous salpingitis. No other focus of infection was detected. The differential diagnosis included trophoblastic tissue, foreign material, and parasites. Scanning electron microscopy and x-ray microanalysis of the organism revealed concentration of iodine in the subcuticular connective tissue of the larva and confirmed the calcium phosphate composition of the calcareous corpuscles. The presumed source of the iodine was the continued exposure of the larva to an environment rich in iodidemore » secreted by the epithelium of the fallopian tube.« less

A novel Na+/HCO3--codependent choline transporter in the syncytial epithelium of the cestode Hymenolepis diminuta.

PubMed

Webb, R A; Xue, L

1998-02-01

Absorption of exogenous choline by the cestode Hymenolepis diminuta was found to be both Na+- and HCO3--dependent and, at pH 6 to 7, accounted for up to 65% of the total choline uptake. Na+/HCO3- dependent choline uptake was activated at approximately 6 mM HCO3- (EC50 approximately 9 mM), and, above 100 mM Na+, the rate of uptake was directly proportional to the Na+ concentration. Atempts to uncouple Na+-dependent uptake from HCO3--dependent uptake were not successful: K+-depolarization was without effect on HCO3--dependent choline uptake, and use of valinoomycin to hyperpolarize the brush-border membrane resulted in inhibition of uptake. Na-/HCO3--dependent choline uptake was not associated with solvent drag. The Na+/HCO3--dependent choline uptake displayed a Q10 of 6.4 (27 degrees to 37 degrees) and a relatively high activation energy of 126 kJ x mol(-1). At pH 6.0 and 7.0, Na-/HCO3--dependent choline uptake rates were similar, but Na+/HCO3--dependent choline uptake was reduced at pH 5.0. The Na+/HCO3--dependent choline uptake, at pH 7.0, displayed a Kt of approximately 500 microM and a Vmax of 4.01 pmol x mg wet weight(-1) x min(-1). The Na+/HCO3--dependent choline uptake was hemicholinium-3 sensitive, but not significantly inhibited by 200 microM bumetanide, 100 microM amiloride, benzamil, or EIPA or by 1 mM 4,4'-diisothiocyano-2,2'-stilbene disulfonate (DIDS) or 4-acetamido-4'-isothiocvanostilbene-2,2'-disulfonic acid (SITS). Although it remains to be shown that HCO3- uptake is coupled directly to both choline and Na+ uptake, the data suggest that choline up take occurs via choline/Na+/HCO3--co-trans porter.

Identification and pharmacological induction of autophagy in the larval stages of Echinococcus granulosus: an active catabolic process in calcareous corpuscles.

PubMed

Loos, Julia A; Caparros, Pedro A; Nicolao, María Celeste; Denegri, Guillermo M; Cumino, Andrea C

2014-06-01

Autophagy is a fundamental catabolic pathway conserved from yeast to mammals, but which remains unknown in parasite cestodes. In this work, the pharmacological induction of autophagy was cellularly and molecularly analysed in the larval stages of Echinococcus granulosus. Metacestode sensitivity to rapamycin and TORC1 expression in protoscoleces and metacestodes were shown. Ultrastructural studies showed that treated parasites had an isolation membrane, autophagosomes and autolysosomes, all of which evidenced the autophagic flux. Genes coding for key autophagy-related proteins were also identified in the Echinococcus genome. These genes were involved in autophagosome formation and transcriptional over-expression of Eg-atg5, Eg-atg6, Eg-atg8, Eg-atg12, Eg-atg16 and Eg-atg18 was shown in presence of rapamycin or arsenic trioxide. Thus, Echinococcus autophagy could be regulated by non-transcriptional inhibition through TOR and by transcription-dependent up-regulation via FoxO-like transcription factors and/or TFEB proteins. An increase in the punctate pattern and Eg-Atg8 polypeptide level in the tegument, parenchyma cells and excretory system of protoscoleces and in vesicularised parasites was detected after rapamycin treatment. This suggests the occurrence of basal autophagy in the larval stages and during vesicular development. In arsenic-treated protoscoleces, high Eg-Atg8 polypeptide levels within the free cytoplasmic matrix of calcareous corpuscles were observed, thus verifying the occurrence of autophagic events. These experiments also confirmed that the calcareous corpuscles are sites of arsenic trioxide accumulation. The detection of the autophagic machinery in this parasite represents a basic starting point to unravel the role of autophagy under both physiological and stress conditions which will allow identification of new strategies for drug discovery against neglected parasitic diseases caused by cestodes. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Invaded Invaders: Infection of Invasive Brown Treesnakes on Guam by an Exotic Larval Cestode with a Life Cycle Comprised of Non-Native Hosts.

PubMed

Holldorf, Elden T; Siers, Shane R; Richmond, Jonathan Q; Klug, Page E; Reed, Robert N

2015-01-01

Multiple host introductions to the same non-native environment have the potential to complete life cycles of parasites incidentally transported with them. Our goal was to identify a recently detected parasitic flatworm in the invasive Brown Treesnake (Boiga irregularis) on the remote Pacific island of Guam. We considered possible factors influencing parasite transmission, and tested for correlations between infection status and potential indicators of host fitness. We used genetic data from the parasite and information about the native ranges of other possible non-native hosts to hypothesize how it arrived on Guam and how its life cycle may be currently supported. We identified the parasite by comparing larval morphology and mtDNA sequences with other Pseudophyllid tapeworms. We assessed probability of infection in individual snakes using logistic regression and examined different factors influencing presence of parasites in hosts. We identified the parasite as the pseudophyllid cestode Spirometra erinaceieuropaei, with all sampled worms from multiple snakes sharing a single mtDNA haplotype. Infection appears to be limited to the only freshwater watershed on the island, where infection prevalence was high (77.5%). Larger snakes had a higher probability of being infected, consistent with the chronic nature of such infections. While infection status was positively correlated with body condition, infected snakes tended to have lower intra-peritoneal fat body mass, potentially indicating a negative effect on energy stores. We discovered that B. irregularis inhabiting a small area of forested habitat in a freshwater watershed on Guam are often infected by a novel parasite of Asian origin. While further work is needed, this species of Spirometra, itself a non-native species, likely depends on a suite of recently introduced hosts from different parts of the world to complete the life cycle. This baseline study provides little evidence of any effects on host fitness, but additional data are needed to more thoroughly explore the consequences of infection in this invasive snake population.

microRNA analysis of Taenia crassiceps cysticerci under praziquantel treatment and genome-wide identification of Taenia solium miRNAs.

PubMed

Pérez, Matías Gastón; Macchiaroli, Natalia; Lichtenstein, Gabriel; Conti, Gabriela; Asurmendi, Sebastián; Milone, Diego Humberto; Stegmayer, Georgina; Kamenetzky, Laura; Cucher, Marcela; Rosenzvit, Mara Cecilia

2017-09-01

MicroRNAs (miRNAs) are small non-coding RNAs that have emerged as important regulators of gene expression and perform critical functions in development and disease. In spite of the increased interest in miRNAs from helminth parasites, no information is available on miRNAs from Taenia solium, the causative agent of cysticercosis, a neglected disease affecting millions of people worldwide. Here we performed a comprehensive analysis of miRNAs from Taenia crassiceps, a laboratory model for T. solium studies, and identified miRNAs in the T. solium genome. Moreover, we analysed the effect of praziquantel, one of the two main drugs used for cysticercosis treatment, on the miRNA expression profile of T. crassiceps cysticerci. Using small RNA-seq and two independent algorithms for miRNA prediction, as well as northern blot validation, we found transcriptional evidence of 39 miRNA loci in T. crassiceps. Since miRNAs were mapped to the T. solium genome, these miRNAs are considered common to both parasites. The miRNA expression profile of T. crassiceps was biased to the same set of highly expressed miRNAs reported in other cestodes. We found a significant altered expression of miR-7b under praziquantel treatment. In addition, we searched for miRNAs predicted to target genes related to drug response. We performed a detailed target prediction for miR-7b and found genes related to drug action. We report an initial approach to study the effect of sub-lethal drug treatment on miRNA expression in a cestode parasite, which provides a platform for further studies of miRNA involvement in drug effects. The results of our work could be applied to drug development and provide basic knowledge of cysticercosis and other neglected helminth infections. Copyright © 2017 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Intestinal helminth fauna of the South American sea lion Otaria flavescens and fur seal Arctocephalus australis from northern Patagonia, Argentina.

PubMed

Hernández-Orts, J S; Montero, F E; Juan-García, A; García, N A; Crespo, E A; Raga, J A; Aznar, F J

2013-09-01

We report on the intestinal helminth fauna of 56 South American sea lions, Otaria flavescens, and 5 South American fur seals, Arctocephalus australis, from northern Patagonia, Argentina. A total of 97,325 helminth specimens were collected from sea lions. Gravid individuals were represented by 6 species of parasites: 1 digenean (Ascocotyle (Ascocotyle) patagoniensis), 1 cestode (Diphyllobothrium spp.), 3 nematodes (Uncinaria hamiltoni, Contracaecum ogmorhini s.s., Pseudoterranova cattani) and 1 acanthocephalan (Corynosoma australe). In addition, third-stage larvae of 2 nematodes (Contracaecum sp. and Anisakis sp. type I) and 3 juvenile acanthocephalans (Andracantha sp., Profilicollis chasmagnathi and Corynosoma cetaceum) were also collected. Andracantha sp., C. ogmorhini s.s. and P. chasmagnathi represent new host records. A total of 1516 helminth specimens were collected from fur seals. Gravid individuals were represented by three species of parasites, namely, Diphyllobothrium spp., C. ogmorhini s.s. and C. australe. In addition, larvae of Contracaecum sp. and P. cattani, juveniles of C. cetaceum and immature cestodes (Tetrabothriidae gen. sp.) were also collected. Corynosoma australe was the most prevalent and abundant parasite in both hosts, accounting for >90% of all specimens. Sea lions and furs seals from northern Patagonia harbour the intestinal helminth communities that could be predicted for otariids, i.e. the combination of species of the genera Corynosoma, Diphyllobothrium, Pseudoterranova, Contracaecum and, in pups, Uncinaria. Additionally, both species of otariid are apparently unsuitable hosts (i.e. non-hosts) for as many as five parasite taxa. The inclusion or exclusion of these species affects estimation of species richness at both component community (11 versus 6 species in sea lions; 7 versus 3 species in fur seals) and infracommunity (mean: 3.1 versus 2.6 in sea lions; 2.2 versus 1.7 species) levels. Information about the reproductive status of helminth species is often lacking in parasitological surveys on otariids and other marine vertebrates, but it is of significance to improve precision in parascript studies or ecological meta-analyses.

Intestinal helminths of golden jackals and red foxes from Tunisia.

PubMed

Lahmar, Samia; Boufana, Belgees; Ben Boubaker, Sarra; Landolsi, Faouzi

2014-08-29

Forty wild canids including 31 golden jackals (Canis aureus Linné, 1758) and 9 red foxes (Vulpes vulpes Linné, 1758) collected between 2008 and 2011 in the northeast, northwest and center of Tunisia were necropsied and examined for intestinal helminth parasites. All jackals and foxes were found infected with a prevalence rate of 95% for cestodes, 82.5% for nematodes and 7.5% for acanthocephalans. A total of twelve helminth species were recorded in red foxes: cestodes, Dipylidium caninum (55.6%), Diplopylidium noelleri (55.6%), Mesocestoïdes lineatus (55.6%), Mesocestoïdes litteratus (33%), Mesocestoïdes corti (22%); nematodes, Ancylostoma caninum (11%), Uncinaria stenocephala (44%), Spirura rytipleurites (11%), Trichuris vulpis (33%), Pterygodermatites affinis (67%), Oxynema linstowi (33%) and the acanthocephalan Macracanthorhynchus hirudinaceus (22%). The fifteen recovered helminth species in jackals were Echinococcus granulosus (9.7%), D. caninum (16%), D. noelleri (16%), M. lineatus (74%), M. litteratus (23%), M. corti (12.9%), Taenia pisiformis (3.2%), Taenia spp. (19%), Toxocara canis (16%), Toxascaris leonina (6.5%), A. caninum (9.7%), U. stenocephala (68%), P. affinis (6.5%), O. linstowi (3.2%) and Macracanthorhynchus hirudinaceus (3.2%). This is the first report on the presence of P. affinis, D. noelleri and O. linstowi in Tunisia. E. granulosus was found in young jackals, aged less than 4 years old, with a higher abundance in females (8.9 worms). M. lineatus presented the highest mean intensity of 231.86 and 108.8 tapeworms respectively in jackals and foxes. Canids from the northwest region had the highest prevalence (77.5%) and highest intensity (243.7) of helminth species compared to those from the northeast and central areas. U. stenocephala and O. linstowi had the highest mean intensity for nematodes in both jackals and foxes at 14.3 and 88 worms respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

The functional importance of sequence versus expression variability of MHC alleles in parasite resistance.

PubMed

Axtner, Jan; Sommer, Simone

2012-12-01

Understanding selection processes driving the pronounced allelic polymorphism of the major histocompatibility complex (MHC) genes and its functional associations to parasite load have been the focus of many recent wildlife studies. Two main selection scenarios are currently debated which explain the susceptibility or resistance to parasite infections either by the effects of (1) specific MHC alleles which are selected frequency-dependent in space and time or (2) a heterozygote or divergent allele advantage. So far, most studies have focused only on structural variance in co-evolutionary processes although this might not be the only trait subject to natural selection. In the present study, we analysed structural variance stretching from exon1 through exon3 of MHC class II DRB genes as well as genotypic expression variance in relation to the gastrointestinal helminth prevalence and infection intensity in wild yellow-necked mice (Apodemus flavicollis). We found support for the functional importance of specific alleles both on the sequence and expression level. By resampling a previously investigated study population we identified specific MHC alleles affected by temporal shifts in parasite pressure and recorded associated changes in allele frequencies. The allele Apfl-DRB*23 was associated with resistance to infections by the oxyurid nematode Syphacia stroma and at the same time with susceptibility to cestode infection intensity. In line with our expectation, MHC mRNA transcript levels tended to be higher in cestode-infected animals carrying the allele Apfl-DRB*23. However, no support for a heterozygote or divergent allele advantage on the sequence or expression level was detected. The individual amino acid distance of genotypes did not explain individual differences in parasite loads and the genetic distance had no effect on MHC genotype expression. For ongoing studies on the functional importance of expression variance in parasite resistance, allele-specific expression data would be preferable.

Trypanorhynch cestodes (Eutetrarhynchidae) from batoids along the coast of Argentina, including the description of new species in Dollfusiella Campbell et Beveridge, 1994 and Mecistobothrium Heinz et Dailey, 1974.

PubMed

Menoret, Adriana; Ivanov, Veronica A

2015-09-07

During a recent parasitological survey of elasmobranchs along the coast of Argentina, two new species of eutetrarhynchid cestodes of the genera Dollfusiella Campbell et Beveridge, 1994 and Mecistobothrium Heinz et Dailey, 1974 were collected from batoids. Dollfusiella acuta sp. n. was found in four arhynchobatid skates, i.e. Sympterygia acuta Garman (type host), Sympterygia bonapartii Müller et Henle, Atlantoraja castelnaui (Miranda Ribeiro) and Atlantoraja platana (Günther), and Mecistobothrium oblongum sp. n. in the eagle ray Myliobatis goodei Garman. Dollfusiella acuta sp. n. has a tentacular armature consisting of basal rows of uncinate hooks, a distinct basal swelling with uncinate, falcate and bill hooks, and a heteroacanthous metabasal armature with heteromorphous hooks (bothrial uncinate hooks and antibothrial falcate hooks), hooks 1(1') not separated, testes in two columns and an internal seminal vesicle. The tentacular armature of M. oblongum sp. n. is characterised by basal rows of uncinate hooks, a basal swelling with uncinate and falcate hooks, a typical heteroacanthous metabasal armature with heteromorphous hooks (uncinate and falcate to spiniform), and hooks 1(1') separated and of a constant size along the tentacle. It also possesses an elongate scolex, numerous testes arranged in 5-6 irregular columns, and an internal seminal vesicle. The discovery of M. oblongum in M. goodei represents the first record of species of Mecistobothrium in the southwestern Atlantic Ocean. An amended description of Dollfusiella cortezensis (Friggens et Duszynski, 2005) is also provided to clarify details of the scolex and tentacular armature. Members of Dollfusiella in the southwestern Atlantic are specific to a single host species or to a particular host family, while M. oblongum was found in a single host species. Although globally some plerocerci of eutetrarhynchids have been found in teleosts, extensive examination of teleosts off the coast of Argentina suggests that the transmission pathways of these species are exclusively based on invertebrates as intermediate or paratenic hosts.

Cysticercosis: Hooked by a Hooklet on Fine Needle Aspiration Cytology—A Case Report

PubMed Central

Sawhney, Manav; Agarwal, Shubhra

2013-01-01

Cysticercosis is a systemic parasitic disease caused by the larval form of cestode T. solium. It has a worldwide distribution and is potentially harmful with variable clinical manifestations. The patient most commonly presents with subcutaneous and muscle involvement in the form of nodular lesions. The other most commonly involved sites include eye, brain, bladder wall, and heart. Cysticercosis can be diagnosed on serology, and radiologically but confirmatory diagnosis is based on histopathological examination of the involved tissue biopsy specimen. Fine needle aspiration cytology is a useful low-cost outpatient procedure tool for preoperative diagnosis of cysticercosis and is absolutely essential for diagnosis of the parasitic lesions in a peripheral hospital, one like ours. PMID:24024052

The passive transfer of immunity to Taenia ovis in lambs via colostrum.

PubMed

Sutton, R J

1979-09-01

Colostrum from ewes that had been repeatedly exposed to cestode infection, whether or not their immunity was boosted by vaccination with Taenia ovis, transferred a strong immunity to the lambs. Susceptible ewes, not recently exposed to tapeworm eggs, gave no protection to their lambs via the colostrum. There was no evidence that colostrum-deprived lambs were more susceptible to infection with T ovis than lambs that received colostrum from non-immune ewes. Colostrum from naturally immune vaccinated ewes gave good protection to lambs for up to six weeks but thereafter the effect was variable. The immunity that developed in susceptible ewes after vaccination with activated embryos was not passed on to the lambs via the colostrum.

How might flukes and tapeworms maintain genome integrity without a canonical piRNA pathway?

PubMed Central

Skinner, Danielle E.; Rinaldi, Gabriel; Koziol, Uriel; Brehm, Klaus; Brindley, Paul J.

2014-01-01

Surveillance by RNA interference is central to controlling the mobilization of transposable elements (TEs). In stem cells, Piwi argonaute (Ago) proteins and associated proteins repress mobilization of TEs to maintain genome integrity. This defense mechanism targeting TEs is termed the Piwi-interacting RNA (Piwi-piRNA) pathway. In this Opinion, we draw attention to the situation that the genomes of cestodes and trematodes have lost the piwi and vasa genes that are hallmark characters of the germline multipotency program. This absence of Piwi-like Agos and Vasa helicases prompts the question: how does the germline of these flatworms withstand mobilization of TEs? Here we present an interpretation of mechanisms likely to defend the germline integrity of parasitic flatworms. PMID:24485046

Echinococcus granulosus: Evidence of a heterodimeric glutathione transferase built up by phylogenetically distant subunits.

PubMed

Arbildi, Paula; La-Rocca, Silvana; Lopez, Veronica; Da-Costa, Natalia; Fernandez, Veronica

2017-01-01

In the cestode parasite Echinococcus granulosus, three phylogenetically distant cytosolic glutathione transferases (GSTs) (EgGST1, 2 and 3) were identified. Interestingly, the C-terminal domains of EgGST3 and EgGST2 but not EgGST1, exhibit all amino acids involved in Sigma-class GST dimerization. Here, we provide evidence indicating that EgGST2 and EgGST3 naturally form a heterodimeric structure (EgGST2-3), and also we report the enzymatic activity of the recombinant heterodimer. EgGST2-3 might display novel properties able to influence the infection establishment. This is the first report of a stable heterodimeric GST built up by phylogenetically distant subunits. Copyright © 2016 Elsevier B.V. All rights reserved.

Description of a new species Fuhrmannetta jurubatensis n. sp. (Cestoda, Davaineidae) from Cerradomys goytaca Tavares, Pessôa & Gonçalves, 2011 (Rodentia, Cricetidae).

PubMed

Oliveira, L C; Oliveira, F C R; Ederli, N B

2017-10-04

A new species of cestode of the genus Fuhrmannetta found in the small intestine of Cerradomys goytaca is described herein, named Fuhrmannetta jurubatensis n. sp. Rodents were collected from the sand-plains areas of the northern coast of the State of Rio de Janeiro, Brazil. Morphological analyses were conducted by light and scanning electron microscopy. From the morphological analysis and a comparison with the known species of the genus, F. jurubatensis n. sp. can be identified by a combination of morphological and morphometrical characteristics, including strobila length, number and length of rostellar hooks, position of the genital pore and the number of eggs per uterine capsule.

Coprology of Panthera tigris altaica and Felis bengalensis euptilurus from the Russian Far East.

PubMed

González, P; Carbonell, E; Urios, V; Rozhnov, V V

2007-08-01

Fecal samples from the Siberian tiger (Panthera tigris altaica) and the Amur cat (Felis bengalensis euptilurus) from Far Eastern Russia, were examined for parasites. A natural sedimentation methodology was used and a complete examination of all the sediment was performed. This fecal investigation allowed us to isolate and identify several developmental stages of gastrointestinal, hepatic, and respiratory parasites. Five parasites were found from P. t. altaica: 11 trematodes (Platynosomum fastosum) and 4 nematodes (Strongyloides sp., Ancylostomatidae, Toxascaris leonina, and Toxocara cati). Five parasites were found from F. b. euptilurus: 1 cestode (Diplopylidium sp.) and 4 nematodes (Trichuris sp., Ancylostomatidae, Toxascaris leonina, and Aelurostrongylus abstrusus). In addition, trophozoites of the amoeba Acanthamoeba sp. were detected in tiger feces.

Helminths infecting the parthenogenetic whiptail lizard Cnemidophorus nativo in a restinga habitat of Bahia State, Brazil.

PubMed

Menezes, V A; Vrcibradic, D; Vicente, J J; Dutra, G F; Rocha, C F D

2004-12-01

A sample of 101 specimens of the unisexual whiptail lizard Cnemidophorus nativo (Squamata; Teiidae) from a coastal site in Bahia State, Brazil were examined for the presence of endoparasites. Of these, 35 (34.7%) harboured helminths. Six helminth species were recovered from C. nativo, including five nematodes (Physaloptera retusa, Physalopteroides venancioi, Subulura lacertilia, Skrjabinelazia intermedia and Parapharyngodon sp., and one cestode (Oochoristica ameivae), all representing new host records. Most lizards were infected by a single species of helminth and none by more than three. Infection rates were neither significantly influenced by host body size nor by environmental factors. The results are compared with data from studies on other whiptail species in both South and North America.

Helminths of the horned leaf frog, Proceratophrys appendiculata, from southeastern Brazil.

PubMed

Boquimpani-Freitas, L; Vrcibradic, D; Vicente, J J; Bursey, C R; Rocha, C F; Van Sluys, M

2001-09-01

The helminth fauna of the horned leaf frog, Proceratophrys appendiculata (Anura: Leptodactylidae), was studied from 17 adult individuals from an island in Rio de Janeiro state, southeastern Brazil. A total of five nematode species (Aplectana delirae, Cosmocerca brasiliense, Schulzia travassosi, Rhabdias androgyna and Physaloptera sp.) and an unidentified cestode were recovered from the digestive tract, lungs and gall bladder of P. appendiculata and all the nematode species are new host records. Aplectana delirae had the highest values for the prevalence and intensity of infection and can thus be considered a core species in the helminth community of P. appendiculata. Aplectana crossodactyli Baker, 1980 is synonymized with Aplectana delirae (Fabio, 1971). The helminth fauna of P. appendiculata presents characteristics typical of those in amphibians.

How might flukes and tapeworms maintain genome integrity without a canonical piRNA pathway?

PubMed

Skinner, Danielle E; Rinaldi, Gabriel; Koziol, Uriel; Brehm, Klaus; Brindley, Paul J

2014-03-01

Surveillance by RNA interference is central to controlling the mobilization of transposable elements (TEs). In stem cells, Piwi argonaute (Ago) proteins and associated proteins repress mobilization of TEs to maintain genome integrity. This defense mechanism targeting TEs is termed the Piwi-interacting RNA (piRNA) pathway. In this opinion article, we draw attention to the situation that the genomes of cestodes and trematodes have lost the piwi and vasa genes that are hallmark characters of the germline multipotency program. This absence of Piwi-like Agos and Vasa helicases prompts the question: how does the germline of these flatworms withstand mobilization of TEs? Here, we present an interpretation of mechanisms likely to defend the germline integrity of parasitic flatworms. Copyright © 2014 Elsevier Ltd. All rights reserved.

A new triaenophorid tapeworm from blackfish Centrolophus niger.

PubMed

Kuchta, Roman; Scholz, Tomás

2008-04-01

Milanella familiaris n. gen. and n. sp. (Bothriocephalidea: Triaenophoridae) is proposed to accommodate a new cestode from blackfish Centrolophus niger (Gmelin) (Perciformes: Centrolophidae). Milanella is characterized as follows: trapeziform, i.e., markedly craspedote proglottids with a velum-like posterior margin and horn like lateral projections; pyriform uterine sac in the first gravid proglottids; arrow-shaped scolex with well-developed apical disc and prominent posterior margins; strobila with intensively stained corpuscles, most numerous in the anterior part; deeply lobated ovary; absence of a neck; a large, pyriform, thin-walled cirrus-sac with the proximal part bent anteromedially; vagina posterior to the cirrus-sac; and cortical vitelline follicles. Milanella most closely resembles Bathycestus Kuchta and Scholz, 2004, Pistana Campbell and Gartner, 1982, and Probothriocephalus Campbell, 1979, differing mainly in the shape of proglottids and uterine sac.

Helminth Parasites of the Lizard Nothobachia ablephara (Gymnophthalmidae) in Caatinga Areas from the Sertão of Brazil.

PubMed

Ribeiro, L B; Ferreira, A C S; Silva, D C N; Vieira, F M; Moura, G J B

2018-04-01

The lizard Nothobachia ablephara is endemic to dune areas and sandy soils adjacent to the São Francisco River in semiarid northeastern Brazil. Forty-nine lizard specimens were collected in 2 Caatinga areas in the municipality of Petrolina in Pernambuco state. Three gastrointestinal helminth taxa were identified, the nematodes Parapharyngodon alvarengai and Physaloptera sp. and the cestode Oochoristica sp. Nothobachia ablephara showed low parasite richness, but high levels of infection by P. alvarengai. There were no significant differences between the parasitism rates of the 2 study areas or between male and female lizards. This is the first study on parasitism in N. ablephara, thereby increasing knowledge of parasite fauna that infect gymnophthalmid lizards in the Sertão of Brazil.

Helminthologic survey of the wolf (Canis lupus) in Estonia, with an emphasis on Echinococcus granulosus.

PubMed

Moks, E; Jõgisalu, I; Saarma, U; Talvik, H; Järvis, T; Valdmann, H

2006-04-01

Carcasses of 26 wolves were collected during the 2000/2001 and 2003/2004 hunting seasons and examined for helminths. Thirteen helminth species were recorded: one trematode (Alaria alata), seven cestodes (Diphyllobothrium latum, Mesocestoides lineatus, Taenia hydatigena, Taenia multiceps, Taenia ovis, Taenia pisiformis, and Echinococcus granulosus), and five nematode species (Uncinaria stenocephala, Toxascaris leonina, Toxocara canis, Trichinella nativa, and Trichinella britovi). The most common species were A. alata and U. stenocephala. Mature Echinococcus granulosus was found and described for the first time in Estonia, and its identity verified using PCR-RFLP analysis. Sequencing a fragment of the mitochondrial DNA NADH dehydrogenase 1 (mtND1) gene showed that the E. granulosus strain from Estonia was identical to strain G10, recently characterized in reindeer and moose in Finland.

Echinococcus ortleppi, the cattle strain in a crested porcupine (Hystrix cristata): A new host record.

PubMed

Hodžić, Adnan; Alić, Amer; Šupić, Jovana; Škapur, Vedad; Duscher, Georg Gerhard

2018-05-30

Echinococcus granulosus sensu lato, a dog tapeworm is a species complex causing cystic echinococcosis or hydatid disease in a great variety of mammalian intermediate hosts, including humans. This complex comprises five species including Echinococcus ortleppi (G5 genotype or cattle strain). In the present paper, we report the first case of infection with the larval stage of latter cestode in a captive crested porcupine (Hystrix cristata), molecularly confirmed by PCR and sequencing of the cox1 and nad1 genes. The food contaminated with the parasite's eggs is the most likely source of the infection. Our data broaden the knowledge on the host range and geographical distribution of this rarely reported species of Echinococcus in Europe. Copyright © 2018 Elsevier B.V. All rights reserved.

Neurocysticercosis: Diagnostic problems & current therapeutic strategies

PubMed Central

Rajshekhar, Vedantam

2016-01-01

Neurocysticercosis (NCC) is the most common single cause of seizures/epilepsy in India and several other endemic countries throughout the world. It is also the most common parasitic disease of the brain caused by the cestode Taenia solium or pork tapeworm. The diagnosis of NCC and the tapeworm carrier (taeniasis) can be relatively inaccessible and expensive for most of the patients. In spite of the introduction of several new immunological tests, neuroimaging remains the main diagnostic test for NCC. The treatment of NCC is also mired in controversy although, there is emerging evidence that albendazole (a cysticidal drug) may be beneficial for patients by reducing the number of seizures and hastening the resolution of live cysts. Currently, there are several diagnostic and management issues which remain unresolved. This review will highlight some of these issues. PMID:28139530

Helminth parasites of the blue-footed booby on Isla Isabel, México.

PubMed

Rubio-Godoy, Miguel; de León, Gerardo Pérez-Ponce; Mendoza-Garfias, Berenit; Carmona-Isunza, María Cristina; la Mora, Alejandra Núñez-de; Drummond, Hugh

2011-08-01

A survey of the helminth fauna of the blue-footed booby, Sula nebouxii, on Isla Isabel, off the Pacific coast of México, is presented. Eight parasite species were found: 4 digeneans (Galactosomum puffini , Mesostephanus microbursa, Opisthometra planicollis, and Renicola thapari), 3 nematodes (Contracaecum sp., Porrocaecum sp., and Tetrameres sp.), and 1 cestode (Tetrabothrius sp). All these species are reported for the first time in the blue-footed booby, and they represent 8 new locality records as well. Species accumulation curves suggest these 8 parasite species comprise the total helminth fauna of this population of boobies. The most frequent and abundant parasite was R. thapari, inhabiting the kidney of its host. In male boobies, a significant negative correlation was found between abundance of R. thapari and host body condition.

Designing a Minimal Intervention Strategy to Control Taenia solium.

PubMed

Lightowlers, Marshall W; Donadeu, Meritxell

2017-06-01

Neurocysticercosis is an important cause of epilepsy in many developing countries. The disease is a zoonosis caused by the cestode parasite Taenia solium. Many potential intervention strategies are available, however none has been able to be implemented and sustained. Here we predict the impact of some T. solium interventions that could be applied to prevent transmission through pigs, the parasite's natural animal intermediate host. These include minimal intervention strategies that are predicted to be effective and likely to be feasible. Logical models are presented which reflect changes in the risk that age cohorts of animals have for their potential to transmit T. solium. Interventions that include a combined application of vaccination, plus chemotherapy in young animals, are the most effective. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Ultrastructure of spermiogenesis of Dipylidium caninum (Cestoda, Cyclophyllidea, Dipylidiidae), an intestinal parasite of Canis familiaris.

PubMed

Miquel, J; Bâ, C T; Marchand, B

1998-09-01

We describe for the first time the ultrastructure of spermiogenesis of a representative of the family Dipylidiidae, Dipylidium caninum. Spermiogenesis begins with the formation of a differentiation zone. This conical area presents two centrioles with associated striated roots. One of the centrioles develops a flagellum and posteriorly a proximodistal fusion is produced between the axoneme and a median cytoplasmic process. In a final stage of spermiogenesis a condensation of electron-dense material between cortical microtubules is observed in the anterior part of the differentiation zone. This is the origin of the crest-like body that appears at the end of spermiogenesis. The presence of striated roots associated with centrioles constitutes the first report of these structures in the spermiogenesis of a cyclophyllidean cestode.

Is alveolar hydatid disease of the liver incurable?

PubMed Central

Mosimann, F

1980-01-01

The etiologic agent of alveolar hydatid disease is Echinococcus multilocularis. Infestation of the liver by the larvae of this Cestode results in an infiltrative mass that behaves biologically very much like a malignant tumor. From 1955 to 1978, 13 patients with alveolar hydatid disease of the liver were investigated, operated and followed at the University Medical Center of Lausanne, Switzerland. Due to the extension of the lesions, six patients had exploratory laparotomy with biopsy only; the other seven were submitted to hepatic resection. Follow-up demonstrated that the disease progresses slowly and that a resection, even if incomplete, can afford long-lasting relief. However the present data suggest that surgical cure of alveolar hydatid disease must be very rare. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:7406556

Observations on the seasonal incidence of myxomatosis and its interactions with helminth parasites in the European rabbit (Oryctolagus cuniculus).

PubMed

Boag, B

1988-07-01

European rabbits (Oryctolagus cuniculus) were collected monthly over a 10-yr period and the incidence of myxomatosis and the size of helminth populations were recorded. Myxomatosis occurred annually, always as an epidemic in the latter half of the year and was associated with both an increase in the percentage of animals infected and the size of the infections of the nematodes Trichostrongylus retortaeformis and Passalurus ambiguus and the cestode Mosgovoyia pectinata. It is suggested that myxomatosis had the effect of reducing the rabbits' overall immune response to infection and that due to the regular annual occurrence of myxomatosis, the resulting increase in the size of helminth infections must be considered an integral part of the population dynamics of these parasites.

Parasites of the Raccoon, Procyon lotor

USGS Publications Warehouse

Clark, G.M.; Herman, C.M.

1959-01-01

At least 76 species of parasites have been reported from raccoons. These include 4 species of protozoa, 27 nematodes, 20 trematodes, 7 cestodes, 3 acanthocephala, and 15 arthropods. In many cases these represent single reports. In other cases some of the parasites are known to be of frequent occurrence and broad geographical range on the basis of several surveys that have been conducted. During the past 30 years 260 raccoons have been examined for parasites at the Patuxent Research Refuge. While most of these animals were collected on the refuge, several were from other localities in Maryland and a few from outside this state. The known distribution and occurrence of parasites of the raccoon are presented on charts and representative specimens of some of those collected at the Patuxent Research Refuge are demonstrated.

Helminths and helminthoses in Central Europe: general overview and diseases caused by trematodes (flukes).

PubMed

Auer, Herbert; Aspöck, Horst

2014-10-01

Parasitic helminths and helminthoses do not only occur in the tropics and subtropics but are also prevalent in Austria and other Central European countries. Their prevalence is, however, more or less rather low. In total, we know more than 20 helminth species, which are diagnosed regularly in Austria; some of them occur in Austria autochthonously, some others are acquired abroad and are transferred as souvenirs to Central Europe. The spectrum of helminths described in this overview comprises species of the trematodes (flukes), cestodes (tapeworms), and nematodes (roundworms).The topic "Helminths and helminthoses in Central Europe" is divided into three parts: The first part comprises a short introduction into the field of medical helminthology and is primarily dedicated to the description of trematodes and trematode-caused diseases.

Angiogenesis and parasitic helminth-associated neovascularization.

PubMed

Dennis, Roger D; Schubert, Uwe; Bauer, Christian

2011-04-01

Successful metazoan parasitism, among many other factors, requires a supply of nutrients and the removal of waste products. There is a prerequisite for a parasite-defined vasculature. The angiogenic mechanism(s) involved presumably depend on the characteristics of the tissue- and vascular system-dwelling, parasitic helminths. Simplistically, 2 possibilities or a combination of both have been considered in this review. The multifactorial induction of parasitic helminth-associated neovascularization could arise through, either a host-, a parasite- or a host-/parasite-dependent, angiogenic switch. Most studies appear to support the first and third hypotheses, but evidence exists for the intrahepatic cestode Echinococcus multilocularis, the free-living nematode Caenorhabditis elegans and the intravascular trematode Schistosoma mansoni for the second inference. In contrast, the nematode anti-coagulant protein NAPc2 from adult Ancylostoma caninum is also an anti-angiogenic factor.

Discrimination between E. granulosus sensu stricto, E. multilocularis and E. shiquicus Using a Multiplex PCR Assay

PubMed Central

Li, Li; Yan, Hong-Bin; Blair, David; Lei, Meng-Tong; Cai, Jin-Zhong; Fan, Yan-Lei; Li, Jian-Qiu; Fu, Bao-Quan; Yang, Yu-Rong; McManus, Donald P.; Jia, Wan-Zhong

2015-01-01

Background Infections of Echinococcus granulosus sensu stricto (s.s), E. multilocularis and E. shiquicus are commonly found co-endemic on the Qinghai-Tibet plateau, China, and an efficient tool is needed to facilitate the detection of infected hosts and for species identification. Methodology/Principal Findings A single-tube multiplex PCR assay was established to differentiate the Echinococcus species responsible for infections in intermediate and definitive hosts. Primers specific for E. granulosus, E. multilocularis and E. shiquicus were designed based on sequences of the mitochondrial NADH dehydrogenase subunit 1 (nad1), NADH dehydrogenase subunit 5 (nad5) and cytochrome c oxidase subunit 1 (cox1) genes, respectively. This multiplex PCR accurately detected Echinococcus DNA without generating nonspecific reaction products. PCR products were of the expected sizes of 219 (nad1), 584 (nad5) and 471 (cox1) bp. Furthermore, the multiplex PCR enabled diagnosis of multiple infections using DNA of protoscoleces and copro-DNA extracted from fecal samples of canine hosts. Specificity of the multiplex PCR was 100% when evaluated using DNA isolated from other cestodes. Sensitivity thresholds were determined for DNA from protoscoleces and from worm eggs, and were calculated as 20 pg of DNA for E. granulosus and E. shiquicus, 10 pg of DNA for E. multilocularis, 2 eggs for E. granulosus, and 1 egg for E. multilocularis. Positive results with copro-DNA could be obtained at day 17 and day 26 after experimental infection of dogs with larval E. multilocularis and E. granulosus, respectively. Conclusions/Significance The multiplex PCR developed in this study is an efficient tool for discriminating E. granulosus, E. multilocularis and E. shiquicus from each other and from other taeniid cestodes. It can be used for the detection of canids infected with E. granulosus s.s. and E. multilocularis using feces collected from these definitive hosts. It can also be used for the identification of the Echinococcus metacestode larva in intermediate hosts, a stage that often cannot be identified to species on visual inspection. PMID:26393793

Genome-wide analysis of regulatory proteases sequences identified through bioinformatics data mining in Taenia solium.

PubMed

Yan, Hong-Bin; Lou, Zhong-Zi; Li, Li; Brindley, Paul J; Zheng, Yadong; Luo, Xuenong; Hou, Junling; Guo, Aijiang; Jia, Wan-Zhong; Cai, Xuepeng

2014-06-04

Cysticercosis remains a major neglected tropical disease of humanity in many regions, especially in sub-Saharan Africa, Central America and elsewhere. Owing to the emerging drug resistance and the inability of current drugs to prevent re-infection, identification of novel vaccines and chemotherapeutic agents against Taenia solium and related helminth pathogens is a public health priority. The T. solium genome and the predicted proteome were reported recently, providing a wealth of information from which new interventional targets might be identified. In order to characterize and classify the entire repertoire of protease-encoding genes of T. solium, which act fundamental biological roles in all life processes, we analyzed the predicted proteins of this cestode through a combination of bioinformatics tools. Functional annotation was performed to yield insights into the signaling processes relevant to the complex developmental cycle of this tapeworm and to highlight a suite of the proteases as potential intervention targets. Within the genome of this helminth parasite, we identified 200 open reading frames encoding proteases from five clans, which correspond to 1.68% of the 11,902 protein-encoding genes predicted to be present in its genome. These proteases include calpains, cytosolic, mitochondrial signal peptidases, ubiquitylation related proteins, and others. Many not only show significant similarity to proteases in the Conserved Domain Database but have conserved active sites and catalytic domains. KEGG Automatic Annotation Server (KAAS) analysis indicated that ~60% of these proteases share strong sequence identities with proteins of the KEGG database, which are involved in human disease, metabolic pathways, genetic information processes, cellular processes, environmental information processes and organismal systems. Also, we identified signal peptides and transmembrane helices through comparative analysis with classes of important regulatory proteases. Phylogenetic analysis using Bayes approach provided support for inferring functional divergence among regulatory cysteine and serine proteases. Numerous putative proteases were identified for the first time in T. solium, and important regulatory proteases have been predicted. This comprehensive analysis not only complements the growing knowledge base of proteolytic enzymes, but also provides a platform from which to expand knowledge of cestode proteases and to explore their biochemistry and potential as intervention targets.

Gastrointestinal helminths of Coyotes (Canis latrans) from Southeast Nebraska and Shenandoah area of Iowa

PubMed Central

Redman, Whitni K.; Bryant, Jay E.; Ahmad, Gul

2016-01-01

Aim: This survey was carried out on the carcasses of 29 coyotes from Southeastern Nebraska and Shenandoah area of Iowa to document the helminths present in the intestinal track of these carnivorous animals. Materials and Methods: A total of 29 adult coyote carcasses were generously donated in the autumn and winter (November-February) of 2014-2015 by trappers, fur buyers and hunters of Southeast Nebraska and Shenandoah area of Iowa. The intestine of individual animals were examined for the recovery of helminth parasites as per the established procedures. Results: We found that as many as 93.10% of the investigated coyotes were infected with one or more helminth infections. A total of 10 different species of helminth parasites were recovered from the intestines of coyotes under investigation. Among the 10 species of helminths, 5 were identified as cestodes while the remaining 5 were nematodes. A total of 82.75% of the animals were infected with one or more species of nematodes, while 75.86% of them were colonized with one or more species of cestode parasites. The most abundant species in coyotes were Toxascaris leonina (68.95%) closely followed by Taenia hydatigena (58.62%). The prevalence of Ancylostoma caninum and Taenia pisiformis were recorded at 31.03%, followed by those of Toxocara canis and Echinococcus spp. at 24.13%, respectively. Three animals were infected with Trichuris vulpis while three other coyotes each were found to be harboring Uncinaria stenocephala, Dipylidium caninum, or Hymenolepis diminuta. The presence of H. diminuta might have been the result of the ingestion of a rodent by the respective coyotes. Conclusion: From the overall analysis of the present data and comparing it with the previous reports of various scientists over several decades, we can conclude that intestinal helminths are still very much prevalent among the coyote population in the Southeast Nebraska and Iowa area. The relatively high prevalence of the zoonotic parasite species further warrants a more comprehensive investigation with larger numbers of wild predators from the region to ascertain the possible contribution of coyotes to the disease cycle as these animals are more frequently spotted in and around the densely populated urban areas. PMID:27733798

Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B

PubMed Central

Obal, Gonzalo; Ramos, Ana Lía; Silva, Valeria; Lima, Analía; Batthyany, Carlos; Bessio, María Inés; Ferreira, Fernando; Salinas, Gustavo; Ferreira, Ana María

2012-01-01

Antigen B (EgAgB) is the most abundant and immunogenic antigen produced by the larval stage (metacestode) of Echinococcus granulosus. It is a lipoprotein, the structure and function of which have not been completely elucidated. EgAgB apolipoprotein components have been well characterised; they share homology with a group of hydrophobic ligand binding proteins (HLBPs) present exclusively in cestode organisms, and consist of different isoforms of 8-kDa proteins encoded by a polymorphic multigene family comprising five subfamilies (EgAgB1 to EgAgB5). In vitro studies have shown that EgAgB apolipoproteins are capable of binding fatty acids. However, the identity of the native lipid components of EgAgB remains unknown. The present work was aimed at characterising the lipid ligands bound to EgAgB in vivo. EgAgB was purified to homogeneity from hydatid cyst fluid and its lipid fraction was extracted using chloroform∶methanol mixtures. This fraction constituted approximately 40–50% of EgAgB total mass. High-performance thin layer chromatography revealed that the native lipid moiety of EgAgB consists of a variety of neutral (mainly triacylglycerides, sterols and sterol esters) and polar (mainly phosphatidylcholine) lipids. Gas-liquid chromatography analysis showed that 16∶0, 18∶0 and 18∶1(n-9) are the most abundant fatty acids in EgAgB. Furthermore, size exclusion chromatography coupled to light scattering demonstrated that EgAgB comprises a population of particles heterogeneous in size, with an average molecular mass of 229 kDa. Our results provide the first direct evidence of the nature of the hydrophobic ligands bound to EgAgB in vivo and indicate that the structure and composition of EgAgB lipoprotein particles are more complex than previously thought, resembling high density plasma lipoproteins. Results are discussed considering what is known on lipid metabolism in cestodes, and taken into account the Echinococcus spp. genomic information regarding both lipid metabolism and the EgAgB gene family. PMID:22616019

Two new species and a new phyllobothriid cestode genus from sharks of the genus Negaprion Whitley (Carcharhiniformes).

PubMed

Ruhnke, T R; Workman, R E

2013-05-01

Alexandercestus n. g. (Cestoda: Tetraphyllidea) is erected for two cestode species found parasitising the two known species of lemon sharks (Carcharhiniformes: Negaprion spp.). This new genus differs from all other phyllobothriid genera except for Hemipristicola Cutmore, Theiss, Bennett & Cribb, 2011, Marsupiobothrium Yamaguti, 1952, Nandocestus Reyda, 2008, Orectolobicestus Ruhnke, Caira & Carpenter 2006, Orygmatobothrium Diesing, 1863, Paraorygmatobothrium Ruhnke, 1994 and Phyllobothrium van Beneden, 1849 in possessing uniloculate bothridia with an apical sucker and neck scutes. Alexandercestus differs from Orectolobicestus and Nandocestus in lacking marginal loculi on the bothridia, from Paraorygmatobothrium in possessing uninterrupted vitelline follicles at the level of the ovary and from Phyllobothrium in being euapolytic as opposed to anapolytic and in lacking posteriorly bifid bothridia. The new genus lacks the central accessory bothridial organ seen in specimens of Orygmatobothrium, and lacks the central bothridial accessory sucker of specimens of Marsupiobothrium. Alexandercestus spp. compare most favourably with specimens of Hemipristicola, especially with respect to aspects of proglottid morphology, but differ in possessing aristate gladiate spinitriches rather than serrate gladiate spinitriches on the proximal bothridial surface. In addition, the bothridia of Alexandercestus spp. are comparatively more fleshy and foliose than those in specimens of Hemipristicola. Two new species of Alexandercestus n. g. are described, Alexandercestus gibsoni n. sp. from Negaprion acutidens, collected from off northern Australia and the Marshall Islands, and Alexandercestus manteri n. sp. from N. brevirostris, collected off the islands of Bimini and the Florida Keys. The two new species differ in total length and vitelline follicle distribution. Bayesian inference and parsimony analysis of the D1-D3 region of the large nuclear ribosomal DNA of 17 published and seven novel sequences placed A. gibsoni as the sister taxon to a clade containing Hemipristicola gunterae Cutmore, Theiss, Bennett & Cribb, 2011 and species of Paraorygmatobothrium. This result supports the erection of Alexandercestus as a genus separate from Hemipristicola and Paraorygmatobothrium. At the present time, species of Alexandercestus are known only from hosts of the carcharhinid genus Negaprion Whitley; examination of extensive survey data suggests this may be the extent of the host distribution of this genus.

Is the red fox (Vulpes vulpes) a competent definitive host for Taenia multiceps?

PubMed

Varcasia, Antonio; Tamponi, Claudia; Tosciri, Gabriele; Pipia, Anna Paola; Dore, Francesco; Schuster, Rolf Karl; Kandil, Omnia Mohamed; Manunta, Maria Lucia; Scala, Antonio

2015-09-25

Shepherd and stray dogs are thought to represent the primary definitive hosts of Coenurosis by Taenia multiceps, due to their feeding habits which translate into high chances of coming into contact with infected intermediate hosts. Nonetheless, little attention has been paid to the role of the red fox (Vulpes vulpes) in the epidemiology of coenurosis. In fact a knowledge gap exists on the role played by red foxes in the epidemiology of Taenia multiceps and the capability of this parasite to produce fertile and viable eggs in this wild canid, i.e. on the occurrence of a sylvatic cycle. This study investigates the role of the red fox (Vulpes vulpes) in the epidemiology of T. multiceps and related metacestodoses. The small intestine of 63 red foxes was macroscopically examined for the presence of cestodes. Adult parasites were identified morphologically as being T. multiceps. Tapeworm eggs were counted and stored at 4 °C in physiological saline solution prior to experimental infection of four sheep and one goat. Sheep were inoculated orally on Day 0 with 3000 (sheep 1), 5000 (sheep 2 and 3) or 7000 eggs (sheep 4), while the goat was infected with 5000 eggs of T. multiceps. The animals were followed-up regularly by MRI and underwent surgical treatment between days 180 to day 240 post infection. Collected coenuri were identified using morphological and molecular methods. A total of 6.3 % of red foxes were found infected with T. multiceps and the eggs obtained from the worms were determined to have a viability of 45.4 %. Two of the challenged sheep and the goat developed disease compatible with T. multiceps. Morphometrical features of the cysts were consistent with those of T. multiceps; nucleotide amplification and sequencing of mitochondrial genes (i.e., cox1 and Nd1) from the metacestode material confirmed the identification. The present study is the first to provide evidence of the role of the red fox as a competent definitive host for T. multiceps, thus changing the epidemiological scenarios of infections by this cestode.

Morphology meets molecules: a new genus and two new species of diphyllidean cestodes from the Yellowspotted skate, Leucoraja wallacei, from South Africa.

PubMed

Abbott, Lauren McKenna; Caira, Janine N

2014-06-01

Two morphologically disparate undescribed species of diphyllidean cestodes from the Yellowspotted skate, Leucoraja wallacei , from South Africa were included in a recent molecular phylogenetic study aimed at revising diphyllidean classification. From a molecular standpoint, these species were determined to be only distantly related to one another. One (originally referred to as Echinobothrium n. sp. 2) showed affinities with species of the batoid-parasitizing Echinobothrium sensu stricto and is described here as Echinobothrium marquesi n. sp. This species most closely resembles Echinobothrium joshuai, an affinity supported by the previous molecular study, but differs in the form of its "B" hooks and degree of overlap between bothria and cephalic peduncle. The other species (originally referred to as New genus n. sp. 1), although exhibiting the full complement of scolex armature, grouped among primarily shark-hosted genera, most of which lack or exhibit reduced scolex armatures. That unexpected result suggested that erection of a novel genus might be warranted, but morphological grounds supporting the action were not apparent at that time. The present study aimed to explore the morphology of this taxon in more detail. Light and scanning electron microscopy revealed this taxon to be exceptional in that its lateral hooklets, which are arranged in 2 clusters like those of Echinobothrium and Coronocestus, are unique in being arranged in anterior and posterior rows, rather than in a single row. Andocadoncum n. gen. is erected, with Andocadoncum meganae n. sp. as its type, to accommodate this taxon. A minor adjustment to the existing hook formula by presenting counts for the anterior hooklets (a) separately from the posterior hooklets (b) readily accommodates this new form. Leucoraja wallacei is distinctive among skates in hosting 2 different genera of diphyllideans. In the context of the previous molecular phylogenetic analyses, it appears that the presence of Andocadoncum n. gen. in this skate species may be the result of a host-switching event involving a weakly or unarmed shark-hosted taxon moving to a batoid-a shift that was likely accompanied by a return to the fully armed condition seen, for example, in other batoid-parasitizing members of the order.

Bothriocephalus pearsei n. sp. (Cestoda: Pseudophyllidea) from cenote fishes of the Yucatan Peninsula, Mexico.

PubMed

Scholz, T; Vargas-Vázquez, J; Moravec, F

1996-10-01

The cestode Bothriocephalus pearsei n. sp. is described from the intestine of the cichlid Cichlasoma urophthalmus (Günther) from cenote (= sinkhole) Zaci near Valladolid, Yucatan, Mexico. The pimelodid catfish Rhamdia guatemalensis Günther, which also harbored conspecific cestodes, seems to represent accidental or postcyclic host of B. pearsei. The new species differs from congeners mainly by the morphology of the scolex, which is clavate, with the maximum width in its middle part, has a distinct but weakly muscular apical disc; 2 short and wide bothria distinctly demarcated in their anterior part, becoming indistinct posteriorly in the middle part of the scolex, and 2 elongate, lateral grooves. In addition to the scolex morphology, the new species can be differentiated from Bothriocephalus species parasitizing North American freshwater fishes as follows: B. claviceps (Goeze, 1782), a specific parasite of eels in the Holarctic, B. cuspidatus Cooper, 1917, occurring mostly in perciform fishes in North America, B. musculosus Baer, 1937 found in the cichlid Cichlasoma biocellata (Regan) (= C. octofasciatum (Regan)), and B. texomensis Self, 1954, described from Hiodon alosoides (Rafinesque), are much larger, with strobilae consisting of relatively short and very wide proglottids versus small-sized strobila (length 26-32 mm) composed of about 70 proglottids, which are only slightly wider than they are long (ratio 1:1-3), rectangular, or even longer than wide in the last proglottids in B. pearsei. Bothriocephalus formosus Mueller and Van Cleave, 1932, described from Percopsis omiscomaycus (Walbaum) in the USA, can be distinguished from B. pearsei, besides the different shape of the scolex, by the distribution of vitelline follicles, which are not separated into 2 lateral fields and are present along the midline of proglottids in the former species. Bothriocephalus acheilognathi, a widely distributed parasite of fishes of many families, in particular of cyprinids, distinctly differs from B. pearsei by its arrow- or heart-shaped scolex, larger strobila, and vitelline follicles scattered along the midline of proglottids in the former taxon. Bothriocephalus pearsei is also typified by its fish hosts, which are both of Neotropical origin, and by its geographical distribution limited to isolated deep-lying cenotes of inferior Yucatan.

Invaded Invaders: Infection of Invasive Brown Treesnakes on Guam by an Exotic Larval Cestode with a Life Cycle Comprised of Non-Native Hosts

PubMed Central

Klug, Page E.; Reed, Robert N.

2015-01-01

Background Multiple host introductions to the same non-native environment have the potential to complete life cycles of parasites incidentally transported with them. Our goal was to identify a recently detected parasitic flatworm in the invasive Brown Treesnake (Boiga irregularis) on the remote Pacific island of Guam. We considered possible factors influencing parasite transmission, and tested for correlations between infection status and potential indicators of host fitness. We used genetic data from the parasite and information about the native ranges of other possible non-native hosts to hypothesize how it arrived on Guam and how its life cycle may be currently supported. Methods We identified the parasite by comparing larval morphology and mtDNA sequences with other Pseudophyllid tapeworms. We assessed probability of infection in individual snakes using logistic regression and examined different factors influencing presence of parasites in hosts. Results We identified the parasite as the pseudophyllid cestode Spirometra erinaceieuropaei, with all sampled worms from multiple snakes sharing a single mtDNA haplotype. Infection appears to be limited to the only freshwater watershed on the island, where infection prevalence was high (77.5%). Larger snakes had a higher probability of being infected, consistent with the chronic nature of such infections. While infection status was positively correlated with body condition, infected snakes tended to have lower intra-peritoneal fat body mass, potentially indicating a negative effect on energy stores. Conclusions We discovered that B. irregularis inhabiting a small area of forested habitat in a freshwater watershed on Guam are often infected by a novel parasite of Asian origin. While further work is needed, this species of Spirometra, itself a non-native species, likely depends on a suite of recently introduced hosts from different parts of the world to complete the life cycle. This baseline study provides little evidence of any effects on host fitness, but additional data are needed to more thoroughly explore the consequences of infection in this invasive snake population. PMID:26699614

microRNA profiling in the zoonotic parasite Echinococcus canadensis using a high-throughput approach.

PubMed

Macchiaroli, Natalia; Cucher, Marcela; Zarowiecki, Magdalena; Maldonado, Lucas; Kamenetzky, Laura; Rosenzvit, Mara Cecilia

2015-02-06

microRNAs (miRNAs), a class of small non-coding RNAs, are key regulators of gene expression at post-transcriptional level and play essential roles in fundamental biological processes such as development and metabolism. The particular developmental and metabolic characteristics of cestode parasites highlight the importance of studying miRNA gene regulation in these organisms. Here, we perform a comprehensive analysis of miRNAs in the parasitic cestode Echinococcus canadensis G7, one of the causative agents of the neglected zoonotic disease cystic echinococcosis. Small RNA libraries from protoscoleces and cyst walls of E. canadensis G7 and protoscoleces of E. granulosus sensu stricto G1 were sequenced using Illumina technology. For miRNA prediction, miRDeep2 core algorithm was used. The output list of candidate precursors was manually curated to generate a high confidence set of miRNAs. Differential expression analysis of miRNAs between stages or species was estimated with DESeq. Expression levels of selected miRNAs were validated using poly-A RT-qPCR. In this study we used a high-throughput approach and found transcriptional evidence of 37 miRNAs thus expanding the miRNA repertoire of E. canadensis G7. Differential expression analysis showed highly regulated miRNAs between life cycle stages, suggesting a role in maintaining the features of each developmental stage or in the regulation of developmental timing. In this work we characterize conserved and novel Echinococcus miRNAs which represent 30 unique miRNA families. Here we confirmed the remarkable loss of conserved miRNA families in E. canadensis, reflecting their low morphological complexity and high adaptation to parasitism. We performed the first in-depth study profiling of small RNAs in the zoonotic parasite E. canadensis G7. We found that miRNAs are the preponderant small RNA silencing molecules, suggesting that these small RNAs could be an essential mechanism of gene regulation in this species. We also identified both parasite specific and divergent miRNAs which are potential biomarkers of infection. This study will provide valuable information for better understanding of the complex biology of this parasite and could help to find new potential targets for therapy and/or diagnosis.

Excretory products of the cestode, Schistocephalus solidus, modulate in vitro responses of leukocytes from its specific host, the three-spined stickleback (Gasterosteus aculeatus).

PubMed

Scharsack, Jörn Peter; Gossens, Anabel; Franke, Frederik; Kurtz, Joachim

2013-12-01

Helminth parasites have evolved remarkable strategies to manipulate the immune system of their hosts. During infections of three-spined stickleback (Gasterosteus aculeatus) with the cestode Schistocephalus solidus prominent immunological changes occur, presumably due to manipulative activity of the parasite. We hypothesise that excretory/secretory products of the parasite are involved in the manipulation of the stickleback's immune system and that this may depend on the individual parasite and its origin. We therefore produced S. solidus conditioned cell culture media (SSCM) with parasites from different origins (Norway, Spain and Germany) and exposed head kidney leukocytes (HKL) from un-infected sticklebacks in cell cultures to SSCM. After in vitro culture, HKL were subjected to differential cell counts (granulocytes/lymphocytes) by means of flow cytometry. Leukocyte sub-populations were analysed for cell viability and changes in cell morphology. The respiratory burst activity was measured with a luminescence assay. Exposure of HKL to SSCM induced an up-regulation of respiratory burst activity after already 1 h, which was still elevated at 24 h, but which was in some cases significantly down-regulated after 96 h. Respiratory burst was positively correlated with the number of live granulocytes in the culture, suggesting that the respiratory burst activity was changed by SSCM effects on granulocyte viability. After 1 h and 24 h of HKL culture, no lymphocyte responses to SSCM were detectable, but after 96 h lymphocyte viability was significantly decreased with SSCM from Spanish S. solidus. In these cultures, residual lymphocytes increased in size, suggesting that cell death and activation might have occurred in parallel. The highest respiratory burst activity was induced by SSCM from Spanish parasites, in particular when they were grown in sympatric sticklebacks. The in vitro HKL responses to SSCM depended on the individual parasite and its population of origin, suggesting that in vivo, S. solidus excretory products are regulated individually, possibly to balance the interplay of each individual host-parasite pair. Copyright © 2013 Elsevier Ltd. All rights reserved.

Parasites of skipjack, Katsuwonus pelamis, from Madeira, Eastern Atlantic.

PubMed

Hermida, Margarida; Cavaleiro, Bárbara; Gouveia, Lídia; Saraiva, Aurélia

2018-04-01

Skipjack tuna, Katsuwonus pelamis, is a tropical species of economic importance for fisheries around the world. It occurs seasonally in subtropical waters around Madeira archipelago, in the warmer months. In this study, a parasitological analysis was carried out on a sample of 30 skipjack caught near Madeira Island. A total of 24 parasite taxa were found in this sample. The skipjack parasite community detected was characterized by a wide diversity of parasites, with a predominance of adult didymozoid trematodes, and high prevalences of Tentacularia coryphaenae cestode larvae and Anisakis sp. larvae. Microhabitat distribution of gill parasites was assessed for the most prevalent species, and correlations between parasite abundance and various host features such as size, condition, and fat content were investigated. Parasite taxa which might be useful as biological tags in future studies of skipjack migrations in the Eastern Atlantic were selected.

The three-spined stickleback-Schistocephalus solidus system: an experimental model for investigating host-parasite interactions in fish.

PubMed

Barber, I; Scharsack, J P

2010-03-01

Plerocercoids of the pseudophyllidean cestode Schistocephalus solidus infect the three-spined stickleback Gasterosteus aculeatus, with important consequences for the biology of host fish. Techniques for culturing the parasite in vitro and generating infective stages that can be used to infect sticklebacks experimentally have been developed, and the system is increasingly used as a laboratory model for investigating aspects of host-parasite interactions. Recent experimental laboratory studies have focused on the immune responses of hosts to infection, the consequences of infection for the growth and reproductive development of host fish and the effects of infection on host behaviour. Here we introduce the host and the parasite, review the major findings of these recent experimental infection studies and identify further aspects of host parasite interactions that might be investigated using the system.

The development of the tapeworm Diphyllobothrium latum (L. 1756) (Cestoda; Pseudophyllidea) in its definitive hosts, with special references to the growth patterns of D. dendriticum (Nitzsch, 1824) and D. ditremum (Creplin, 1827).

PubMed

Andersen, K

1978-08-01

When Diphyllobothrium latum develops from larva to adult in a definitive host, it first sheds the entire larval 'body' before growth of an adult strobila starts. This process of shedding off the entire larval abothrial extremity, piece by piece, takes about 48 h. By this time the larva has usually reached the anterior third of the small intestine of the host. D. dendriticum and D. ditremum develop quite differently, although exhibiting similar anterior migrations. In these two species the larvae develop directly into adults without the larval 'body' first being shed. The implications of the observed differences in growth pattern between these three species of Diphyllobothrium to the classification of diphyllobothriid cestodes is discussed briefly.

A SIMPLE AND EFFECTIVE MULTIPLEX PCR TECHNIQUE FOR DETECTING HUMAN PATHOGENIC TAENIA EGGS IN HOUSEFLIES.

PubMed

Pornruseetriratn, Siritavee; Maipanich, Wanna; Sa-nguankiat, Surapol; Pubampen, Somchit; Poodeepiyasawat, Akkarin; Thaenkham, Urusa

2017-01-01

Taenia solium, T. saginata, and T. asiatica are cestode pathogens causing taeniasis in humans. Houseflies can transfer Taenia eggs to food. However, houseflies are thought to carry only small numbers of Taenia eggs, sometimes fewer than 10. Although several PCR-based methods have been developed to detect Taenia DNA, these require more than 10 eggs for adequate detection. We developed a multiplex PCR method with high specificity for the discrimination among the eggs of the three Taenia species, T. solium, T. saginata, and T. asiatica, using 18S ribosomal DNA (rDNA) as a genetic marker. This technique was found to be highly sensitive, capable of identifying the Taenia species from only one egg. This multiplex PCR technique using 18S rDNA specific primers should be suitable to diagnose Taenia eggs.

Helminthic infections mimicking malignancy: a review of published case reports.

PubMed

Pilsczek, Florian H

2010-08-04

Infectious diseases, including infections with helminths, can initially present similarly to malignancies. The goal of the article is to review reports of helminthic infections that are initially diagnosed as malignancy. The database PubMed was searched for English language references published as of July 2009. The following published case reports and case series, mainly from Asia and Africa, were identified: Nematodes: 8 publications (1 patient with Angiostrongylus cantonensis, 2 Stronglyloides stercoralis, 1 Toxocara species, 1 Dioctophyma renale, 1 Ascaris species, 1 Gnathostoma spinigerum, 1 Dirofilaria repens); Trematodes: 7 publications (46 patients with Schistosoma species, 2 Fasciola hepatica, 1 Paragonimus westermani); Cestodes: 6 publications (10 patients with Echinococcus species, 1 Sparganum mansoni). To avoid unnecessary investigations and treatment, physicians should be aware when diagnosing patients from Asia or Africa that a large number of helminthic infections can present similar to malignancies.

The development of acquired immunity to tapeworms and progress towards active immunization, with special reference to Echinococcus spp

PubMed Central

Gemmell, M. A.; Soulsby, E. J. L.

1968-01-01

An assessment is made of the present state of knowledge on acquired immune responses developed by the intermediate and definitive hosts to tapeworm infections. From this evaluation, some gaps in knowledge and some of the problems associated with the development of practical immunization techniques are described. The principal conclusion reached is that absolute resistance to the larval stage can be acquired and resistance to a number of cestode species can be artificially induced in a number of hosts. Thus, research directed towards isolation and characterization of the functional antigens may lead to the development of vaccines for use in public health programmes, such as for the control of echinococcosis, as well as for improving the present status of meat hygiene in regions where cysticercosis, for example, exists. PMID:4883063

Helminth parasites of the Mediterranean gecko, Hemidactylus turcicus (Sauria: Gekkonidae), from Texas, United States with a summary of helminths of this host.

PubMed

McAllister, Chris T; Bursey, Charles R

2016-09-01

One hundred-thirty six Mediterranean geckos, Hemidactylus turcicus, were collected between December 1986 and March 2016 in Hardin (n = 7), Harris (n = 57), and Tom Green (n = 72) counties, Texas, USA., and examined for helminth parasites. Fifty-two H. turcicus (38%) were infected with at least one helminth species. Found were a trematode, Mesocoelium meggitti, three cestodes, Mesocestoides sp. (tetrathyridia), Oochoristica ameivae and Oochoristica scelopori, and four nematodes, Cosmocercoides variabilis, Oswaldocruzia pipiens, Parapharyngodon cubensis, and larvae of Physaloptera sp. Oochoristica ameivae, O. scelopori, P. cubensis, Physaloptera sp., and Os. pipiens represent new host records for H. turcicus and M. meggitti is reported from Texas for the first time. A summary of the helminth parasites of both native and non-native H. turcicus is presented.

Addition of a combination of onion (Allium cepa) and coconut (Cocos nucifera) to food of sheep stops gastrointestinal helminthic infections.

PubMed

Mehlhorn, Heinz; Al-Quraishy, Saleh; Al-Rasheid, Khaled A S; Jatzlau, Antje; Abdel-Ghaffar, Fathy

2011-04-01

Sheep with gastrointestinal nematodes and cestodes were fed on three farms with a combination of specially prepared extracts of onion (Allium cepa) and coconut (Cocos nucifera) for 8 days containing each 60 g coconut and onion extract, combined with milk powder and/or polyethylene glycol (PEG) propylencarbonate (PC). In all cases, the worm stages disappeared from the feces and were also not found 9 and 20 days after the end of the feeding with this plant combination. Since all treated animals increased their body weight considerably (when compared to untreated animals), worm reduction was apparently as effective as it was shown in previous laboratory trials with rats and mice (Klimpel et al., Parasitol Res, in press, 2010; Abdel-Ghaffar et al., Parasitol Res, in press, 2010; in this volume).

Metazoan parasites of Brama australis from southern Chile: a tool for stock discrimination?

PubMed

Oliva, M E; Espinola, J F; Ñacari, L A

2016-03-01

The metazoan parasites of 403 specimens of the southern ray's bream Brama australis from three localities in southern Chile (Lebu 36° 70' S; 73° 40' W, Calbuco 41° 50' S; 73° 08' W and Punta Arenas 53° 10' S; 70° 50' W) were recorded. More than 23 400 parasite specimens belonging to 12 taxa were registered. Metazoan parasites were dominated by the copepod Hatschekia conifera, constituting 97% of the total number of parasites; the larval cestode Hepatoxylon trichiuri was the second most important parasite (2·1% of the total number of parasites). The remaining 10 species constituted <1% of the metazoan parasites. Parasitological evidence, based on univariate and multivariate analysis, does not support the existence of discrete stocks in the studied zone. © 2016 The Fisheries Society of the British Isles.

Proliferation of pronephric lymphocytes of carp, Cyprinus carpio induced by extracts of Bothriocephalus acheilognathi.

PubMed

Nie, P; Hoole, D; Arme, C

1996-06-01

The interaction between Bothriocephalus acheilognathi Yamaguti, 1934 (Cestoda) and pronephric lymphocytes of carp, Cyprinus carpio L. was studied by examining proliferation of lymphocytes isolated from both naïve fish and fish injected intraperitoneally with cestode extract. Lymphocytes from naïve hosts were stimulated to proliferate in the presence of the extract depending upon the extract protein concentrations; lower concentrations (0.01-0.05 microgram/ml) induced the greatest response, and immunosuppression occurred at higher concentrations. Significant differences were noted in fish that received intraperitoneal injections of parasite extracts. Five days post-injection, lymphocyte proliferation was significantly greater in these individuals compared with sham injected or untreated controls. This difference was reduced at 10 days post-injection, although the response was dependent on the concentration of the parasite extract. The possible significance of the observed stimulation/suppression of lymphocyte activity to establishment of the parasite in the wild is discussed.

Echinococcosis: disease, detection and transmission.

PubMed

Craig, P S; Rogan, M T; Campos-Ponce, M

2003-01-01

Echinococcosis is one of the world's most geographically widespread parasitic zoonoses, with transmission occurring in tropical, temperate and arctic biomes. Most human infections are due to Echinococcus granulosus transmitted between domestic dogs and livestock, but this cosmopolitan species also cycles between wild carnivores (principally canids) and wild ungulates. The other species with significant zoonotic potential is E. multilocularis that occurs naturally in fox definitive hosts and small mammal intermediate hosts. These two species cause human cystic or alveolar echinococcosis respectively, which may be considered serious public health problems in several regions including developed countries. This review provides an introductory overview to the Supplement and summarises the biology and epidemiology of these two related cestodes with an emphasis on applied aspects relating to detection, diagnosis and surveillance in animal and human populations, and includes aspects of transmission ecology, and also considers aspects of community epidemiology and potential for control.

Redescription of Electrotaenia malopteruri (Fritsch, 1886) (Cestoda: Proteocephalidae), a parasite of Malapterurus electricus (Siluriformes: Malapteruridae) from Egypt.

PubMed

de Chambrier, Alain; Scholz, Tomás; Ibraheem, Mohammed Hasan

2004-02-01

The proteocephalidean cestode Electrotaenia malopteruri (Fritsch, 1886) (Proteocephalidae: Gangesiinae), the type- and only species of Electrotaenia Nybelin, 1942 and specific to the electric catfish Malapterurus electricus Gmelin (Siluriformes: Malapteruridae), is redescribed on the basis of freshly collected material from the River Nile in Egypt. The validity of Electrotaenia is confirmed and some unique characters of this genus, observed in extensive material from different host specimens from Egypt, Sudan, Sierra Leone and Nigeria are first reported or described in detail. Such details include the internal morphology of a rostellum-like apical organ which is disc-shaped with a flat or slightly concave apex, the structure of the ovary which is follicular to reticulate, the structure of the cirrus-sac, the presence of a medio-dorsal band of muscle fibres, and the morphology of the vagina and eggs.

Taeniasis and cysticercosis due to Taenia solium in Japan

PubMed Central

2012-01-01

Taenia solium is a zoonotic cestode that causes taeniasis and cysticercosis in humans. The parasite is traditionally found in developing countries where undercooked pork is consumed under poor sanitary conditions and/or as part of traditional food cultures. However, the recent increase in international tourism and immigration is spreading the disease into non-endemic developed countries such as the United States. Although there has been concern that the number of cysticercosis cases is increasing in Japan, the current situation is not clear. This is largely because taeniasis and cysticercosis are not notifiable conditions in Japan and because there have been no comprehensive reviews of T. solium infections in Japan conducted in the last 15 years. Herein, we provide an overview of the status of T. solium infection in Japan over the past 35 years and point out the potential risks to Japanese society. PMID:22248435

Taeniasis and cysticercosis due to Taenia solium in Japan.

PubMed

Yanagida, Tetsuya; Sako, Yasuhito; Nakao, Minoru; Nakaya, Kazuhiro; Ito, Akira

2012-01-17

Taenia solium is a zoonotic cestode that causes taeniasis and cysticercosis in humans. The parasite is traditionally found in developing countries where undercooked pork is consumed under poor sanitary conditions and/or as part of traditional food cultures. However, the recent increase in international tourism and immigration is spreading the disease into non-endemic developed countries such as the United States. Although there has been concern that the number of cysticercosis cases is increasing in Japan, the current situation is not clear. This is largely because taeniasis and cysticercosis are not notifiable conditions in Japan and because there have been no comprehensive reviews of T. solium infections in Japan conducted in the last 15 years. Herein, we provide an overview of the status of T. solium infection in Japan over the past 35 years and point out the potential risks to Japanese society.

Cestodes of the family Dilepididae (Cestoda:Cyclophyllidea) from fish-eating birds in Mexico: a survey of species.

PubMed

Scholz, Tomás; Kuchta, Roman; Salgado-Madonado, Guillermo

2002-07-01

A survey of adults of dilepidid tapeworms (Cyclophyllidea) from piscivorous birds from Mexico is presented on the basis of the taxonomic evaluation of freshly collected and voucher specimens. The following species are reported (first records from Mexico marked with an asterisk): Cyclustera capito (Rudolphi, 1819); *C. ibisae (Schmidt & Bush, 1972); *Dendrouterina ardeae Rausch, 1955; *D. herodiae Fuhrmann, 1912; *D. papillifera (Fuhrmann, 1908); Glossocercus auritus (Rudolphi, 1819); *Neogryporhynchus cheilancristrotus (Wedl, 1855); Paradilepis caballeroi Rysavy & Macko, 1973; Paradilepis sp.; Parvitaenia cochlearii Coil, 1955; and Valipora mutabilis Linton, 1927. Dendrouteria herodiae is reported from America for the first time. New definitive hosts are Phalacrocorax olivaceus for C. capito, N. cheilancristrotus and P. caballeroi; Casmerodius albus and Egretta thula for G. auritus; and E. thula for D. herodiae. Data on the morphology of the rostellar hooks of all species, their hosts and distribution in Mexico are provided.

Helminth parasites and arthropods of feral cats.

PubMed

Coman, B J; Jones, E H; Driesen, M A

1981-07-01

The prevalence (%) of helminth parasites in 327 mainly adult feral cats from 3 habitat groupings in Victoria and New South Wales was determined. The cestodes Taenia taeniaeformis (33%) and Spirometra erinacei (33%) were common; Dipylidium caninum was rate (2%). The nematodes Toxocara cati (28%), Cyathospirura dasyuridis and Cylicospirura felineus combined (27%) and Aelurostrongylus abstrusus (14%) were common but their prevalence differed markedly between habitats. Ollulanus tricuspis (5%), Gnathostoma spinigerum (less than 1%) and an Acanthocephala, Onicola sp (19%), also occurred. Arthropod parasites were collected from 204 of these cats, Ctenocephalides felis (16%) and Echidnophaga spp. (28%) were common. Spilopsyllus cuniculi (3%) and Ctenocephalides canis and Nosopsyllus fasciatus (less than 1% each) were rare. Other rare ectoparasites were the louse, Felicola subrostrata (4%), the mites, Otodectes cynotis, Cheyletiella sp and a trombiculid (less than 1% each); and the tick lxodes tasmani (less than 1%). There was no correlation between degree of parasitism and general condition of the cats.

A hundred years of controversy about the taxonomic status of Echinococcus species.

PubMed

Tappe, Dennis; Kern, Petra; Frosch, Matthias; Kern, Peter

2010-09-01

The parasitic diseases which we know today as cystic and alveolar echinococcosis are zoonoses known since antique times, and 1855, respectively. Whether the two clinically and morphologically distinct diseases were caused, according to a "unicistic" and a "dualistic" theory, by only one or two different cestode species was the subject of a fierce, 100 years long debate involving scientists from many countries. The natural life cycle of Echinococcus granulosus was fully clarified in 1855 after successful animal experiments. In contrast, the natural final and intermediate hosts of Echinococcus multilocularis remained unknown, and the advocates of either theory had to draw on a number of surrogate arguments to defend their positions. The seesaw of reasoning and mutual defeats of the two theories, and the final recognition of E. multilocularis as an independent species in the 1950s are described in this article. 2010 Elsevier B.V. All rights reserved.

Diversity and distribution of fish tapeworms of the "Bothriocephalidea" (Eucestoda).

PubMed

Kuchta, R; Scholz, T

2007-09-01

Recent studies have demonstrated the invalidity of the Pseudophyllidea, a long-term recognised order of tapeworms (Platyhelminthes: Cestoda), typical in possessing two dorsoventrally situated attachment organs called bothria. In fact, cestodes parasitic in tetrapods, especially mammals including man, form a relatively basal group called provisionally the "Diphyllobothriidea", whereas tapeworms occurring in freshwater and marine fish, with a few taxa known from amphibians (frogs and newts), belong to a more derived clade, for which the name "Bothriocephalidea" is tentatively proposed. Revision of the "Bothriocephalidea", based on literary data, study of type- and voucher specimens and extensive newly collected material made it possible to critically review the species composition of the group and to prepare a tentative list of its valid species. Out of 305 nominal taxa, only 125 species are considered to be valid. In addition, the spectrum of definitive hosts and geographical distribution of bothriocephalideans are briefly discussed.

Molecular identification and characterization of prohibitin from Echinococcus granulosus.

PubMed

Zhong, Xiuqin; Song, Xingju; Wang, Ning; Hu, Dandan; Liu, Tinayu; Wang, Tao; Gu, Xiaobin; Lai, Weimin; Peng, Xuerong; Yang, Guangyou

2016-02-01

Prohibitin (PHB) is a widely distributed protein that functions as a molecular chaperone, is involved in the regulation of cell cycle, and maintains mitochondrial structure and functions of the anti-apoptosis, senescence, and proliferation. The aim of this study was to characterize PHB in Echinococcus granulosus (EgPHB), a harmful cestode parasite of humans, many livestock species, and wild animals. We found that EgPHB is a conserved SPFH (stomatin, prohibitin, flotillin, and HflK/C) domain-containing protein, consisting of 289 amino acids, which shares 42.66-99.31% identity with PHBs from other parasites and mammals. EgPHB was located mainly in the tegument issue of protoscoleces, in the inner body of adult worms, and was expressed widely in the germinal layer. This is the first report on prohibitin from E. granulosus, and EgPHB is considered to be a valuable protein to study more in the future.

Abnormalities in the WFU strain of Taenia crassiceps (Cyclophyllidea: Taeniidae) following years of propagation in mice.

PubMed

Aguilar-Vega, L; García-Prieto, L; Zurabian, R

2016-09-01

Asexually proliferating Taenia crassiceps (Zeder, 1800) metacestodes isolated within past decades have been successfully sub-cultured under experimental conditions using Mus musculus Linnaeus, 1758 mice. However, during their development, morphological irregularities of scolex structures have been reported in two of the three strains of this cestode species maintained in mice - ORF and KBS. The main goal of this work is to describe the abnormalities observed in a sample of 118 cysticerci of the third T. crassiceps strain used at present - WFU. Morphological abnormalities were detected in 39.8% of the evaginated scoleces; they consisted of supernumerary suckers (n= 2), duplicated (n= 2) or absent rostellum (n= 1), as well as absent or aberrant (n= 29) hooks, which were significantly shorter when compared to the large and short hook lengths referred to in the literature.

Niclosamide as a treatment for Hymenolepis diminuta and Dipylidium caninum infection in man.

PubMed

Jones, W E

1979-03-01

In the 5-year period 1973-1977, 43 patients infected with Dipylidium caninum and 43 patients infected with Hymenolepis diminuta were treated with Yomesan (niclosamide) in the dosages recommended by the Parasitic Disease Drug Service, Center for Disease Control. The first post-treatment stool specimen and 1-week and 3-month specimens were examined in 13 patients with D. caninum and 19 patients with H. diminuta. One hundred percent (13/13) of those with D. caninum and 89% (17/19) of those with H. diminuta had negative examinations at 3 months and were considered cured. Two patients with persistent H. diminuta were cured with a second course of drug without changing the dosage or time schedule. Four of these cases had been unresponsive to an initial course of quinacrine hydrochloride. Thus, niclosamide seems to be an effective, relatively nontoxic drug for the initial therapy of these cestode infections.

Effects on the development of Dipylidium caninum and on the host reaction to this parasite in the adult flea (Ctenocephalides felis felis).

PubMed

Pugh, R E

1987-01-01

Temperature was found to be a major factor affecting the development of Dipylidium caninum and the presence of a host reaction of adult Ctenocephalides felis felis to D. caninum. Adult fleas reared at 30-32 degrees C contained fully developed metacestodes when they emerged from their cocoons. However at lower temperatures, D. caninum could not complete development until the flea hosts had spent some time on their mammalian hosts. It was the surface temperature of the mammals (31-36 degrees C) and not the fleas' blood meals which resulted in the metacestodes completing their development. This development of D. caninum was therefore independent of the flea development. At 20 degrees C, a larger and more prolonged host reaction was mounted than at higher temperatures. The larval flea diet had a small effect on the subsequent cestode development and the adult fleas' reaction to it.

An immunocytochemical, histochemical and ultrastructural study of the nervous system of the tapeworm Cyathocephalus truncatus (Cestoda, Spathebothriidea).

PubMed

Terenina, Nadezhda B; Poddubnaya, Larisa G; Tolstenkov, Oleg O; Gustafsson, Margaretha K S

2009-01-01

This study is the first detailed study of the organisation of the neuromuscular system of Cyathocephalus truncatus (Cestoda, Spathebothriidea). Five techniques have been used: (1) immunocytochemistry, (2) staining with TRITC-conjugated phalloidin, (3) NADPHdiaphorase histochemistry, (4) confocal scanning laser microscopy and (5) transmission electron microscopy. The patterns of nerves immunoreactive (IR) to antibodies towards serotonin (5-HT) and the invertebrate neuropeptide FMRFamide are described in relation to the musculature. The patterns of NADPHdiaphorase positive nerves and 5-HT-IR nerves are compared. The fine structure of the nervous system (NS) is described. The organisation of NS in the non-segmented, polyzoic C. truncatus differs clearly from that in the non-segmented, monozoic Caryophyllaeus laticeps and shows distinct similarities with the NS in pseudophyllidean cestodes. This supports the hypothesis that taxon Caryophyllidea and Spatheobothriidea form independent lineages within Eucestoda.

[Helminths of carnivores relevant to veterinary practice].

PubMed

Hasslinger, M A

1986-01-01

Especially in an urban environment man and carnivores live closely together, whereby one has to pay attention not only to animal parasites, but also to human pathogenic connections regarding these parasites. Because of the infection risk the animal owner has to be competently informed by his veterinarian. While some cestodes make great demands on hygiene, with others the cycle can be interrupted by consequent diet restrictions. Of all nematodes the stomach worm of the cat is of greater importance as it is easily overlooked because of its small size, is difficult to diagnose and is occurring in our regions with an infestation rate of about 40%. "Larva migrans visceralis" and "Larva migrans cutanea" caused by ascaride and hookworm larvae are important in human medicine and demand therapeutic measures. The contamination of parks, playgrounds and beaches with these parasites caused by carnivores requires a critical evaluation of the human pathogen interests.

Intestinal parasites of raccoons (Procyon lotor) from southwest British Columbia.

PubMed Central

Ching, H L; Leighton, B J; Stephen, C

2000-01-01

This is the first extensive survey of metazoan parasites (particularly of the roundworm Baylisascaris procyonis) from the intestines of raccoons in British Columbia. The sample collected in 1997-1998 consisted of 82 raccoons that had been sick or had been killed accidentally by automobiles. Fifteen parasite taxa were found: 3 nematodes, 9 digenetic trematodes, 2 acanthocephalans and 1 cestode. Ten of these parasites constitute new host records for raccoons, including 4 digenetic trematodes that have been reported in marine birds and mammals on the Pacific Coast of North America. Baylisascaris procyonis infected 61% of the raccoons with a mean intensity of 27. The high rate of infection indicates a large potential for environmental contamination and, thus, human and animal exposure to infectious eggs. Prevention of larva migrans is discussed, particularly for people in contact with raccoons in wildlife rehabilitation centers. PMID:10805249

Gastrointestinal parasites of the colobus monkeys of Uganda.

PubMed

Gillespie, Thomas R; Greiner, Ellis C; Chapman, Colin A

2005-06-01

From August 1997 to July 2003, we collected 2,103 fecal samples from free-ranging individuals of the 3 colobus monkey species of Uganda-the endangered red colobus (Piliocolobus tephrosceles), the eastern black-and-white colobus (Colobus guereza), and the Angolan black-and-white colobus (C. angolensis)--to identify and determine the prevalence of gastrointestinal parasites. Helminth eggs, larvae, and protozoan cysts were isolated by sodium nitrate flotation and fecal sedimentation. Coprocultures facilitated identification of helminths. Seven nematodes (Strongyloides fulleborni, S. stercoralis, Oesophagostomum sp., an unidentified strongyle, Trichuris sp., Ascaris sp., and Colobenterobius sp.), 1 cestode (Bertiella sp.), 1 trematode (Dicrocoeliidae), and 3 protozoans (Entamoeba coli, E. histolytica, and Giardia lamblia) were detected. Seasonal patterns of infection were not apparent for any parasite species infecting colobus monkeys. Prevalence of S. fulleborni was higher in adult male compared to adult female red colobus, but prevalence did not differ for any other shared parasite species between age and sex classes.

Pterobothrium crassicolle parasitizing Paralichthys orbignyanus (Osteichthyes, Paralichthyidae) in Brazil.

PubMed

Felizardo, Nilza N; Knoff, Marcelo; Diniz, Jessica B; Torres, Eduardo J L; Calixto, Flávia A A; Clemente, Sérgio C São

2018-01-01

From September 2014 to November 2015, 30 Paralichthys orbignyanus specimens were obtained from Sepetiba Bay in the municipality of Rio de Janeiro, State of Rio de Janeiro, Brazil. The fishes were necropsied and cestode larvae were recovered from the abdominal cavity, mesentery, and serosas of the stomach, intestine, spleen, liver, kidney and gonads. Nineteen fish were parasitized by a total of 90 trypanorhynch plerocerci. Based on morphological characters, these were identified as Pterobothrium crassicolle. The parasitism indices for P. crassicolle on P. orbignyanus, were 63.3% for prevalence, 4.7 for mean intensity, 3 for mean abundance and 1 to 18 for range of infection. These parasites were studied due to their importance during fish sanitary inspection, if one considers the harm that the repulsive aspect of infected fish may cause to consumers. This is the first record of P. crassicolle plerocerci parasitizing P. orbignyanus.

A Rapid and Convenient Method for in Vivo Fluorescent Imaging of Protoscolices of Echinococcus multilocularis.

PubMed

Yang, Tao; Wang, Sibo; Zhang, Xuyong; Xia, Jie; Guo, Jun; Hou, Jixue; Zhang, Hongwei; Chen, Xueling; Wu, Xiangwei

2016-04-01

Human and animal alveolar echinococcosis (AE) are important helminth infections endemic in wide areas of the Northern hemisphere. Monitoring Echinococcus multilocularis viability and spread using real-time fluorescent imaging in vivo provides a fast method to evaluate the load of parasite. Here, we generated a kind of fluorescent protoscolices in vivo imaging model and utilized this model to assess the activity against E. multilocularis protoscolices of metformin (Met). Results indicated that JC-1 tagged E. multilocularis can be reliably and confidently used to monitor protoscolices in vitro and in vivo. The availability of this transient in vivo fluorescent imaging of E. multilocularis protoscolices constitutes an important step toward the long term bio-imaging research of the AE-infected mouse models. In addition, this will be of great interest for further research on infection strategies and development of drugs and vaccines against E. multilocularis and other cestodes.

Endo-parasite fauna of rodents caught in five wet markets in Kuala Lumpur and its potential zoonotic implications.

PubMed

Paramasvaran, S; Sani, R A; Hassan, L; Hanjeet, K; Krishnasamy, M; John, J; Santhana, R; Sumarni, M G; Lim, K H

2009-04-01

Rodents were collected from five wet markets (Chow Kit, Dato Keramat, Setapak, Jinjang and Kepong) in Kuala Lumpur, Federal Territory between March to April 2006. Ninety seven rats were trapped using wire traps measuring 29 x 22 x 50 cm baited with fruits, coconuts, dried fish or sweet potatoes. A total of 17 different species of parasites were identified from three species of rats out of which 11 (65%) were identified to be zoonotic. The helminths identified from the urban rats were nematodes- Capillaria hepatica, Gongylonema neoplasticum, Heterakis spumosa, Heterakis sp., Masterphorus muris, Nippostrongylus brasiliensis, Physolaptera sp., Pterogodermatis sp., Rictularia tani and Syphacia muris; cestodes- Hymenolepis nana, Hymenolepis diminuta, Hymenolepis sabnema, Hymenolepis sp., Raillietina sp. and Taenia taeniaeformis, and acanthocephalan- Moniliformis moniliformis. The following parasites are of potential medical importance: C. hepatica, G. neoplasticum, R. tani, S. muris, H. diminuta, H. nana, Raillietina sp. and T. taeniaeformis.

Zoonotic helminths parasites in the digestive tract of feral dogs and cats in Guangxi, China.

PubMed

Fang, Fang; Li, Jian; Huang, Tengfei; Guillot, Jacques; Huang, Weiyi

2015-08-16

In Guangxi, a province of southern China, an important number of dogs and cats roam freely in rural settings, and the presence of these animals in proximity of people may represent a risk of parasitic zoonoses. The objective of the present study was to investigate the presence and identify gastrointestinal helminths in feral carnivores in Guangxi province. Therefore, post mortem examination was performed in 40 dogs and in 39 cats. The Gastrointestinal helminths were found in all the necropsied dogs and in 37 out of 39 cats. Fifteen species were identified including 7 trematodes, 3 cestodes and 5 nematodes. Most of them may be responsible for zoonotic infections. Major zoonotic gastrointestinal helminths, including liver and intestinal flukes, Toxocara spp., and Ancylostoma spp., are present in feral dogs and cats in Guangxi, and may represent a significant risk for public health.

Beak and feather disease virus carriage by Knemidocoptes pilae in a sulphur-crested cockatoo (Cacatua galerita).

PubMed

Portas, T; Jackson, B; Das, S; Shamsi, S; Raidal, S R

2017-12-01

This paper describes the pathology associated with psittacine beak and feather disease in a wild sulphur-crested cockatoo with concurrent knemidocoptic mange, cestodiasis and mycotic encephalitis. Large numbers of Knemidocoptes pilae Lavoipierre and Griffiths, 1951 (Acari: Epidermoptidae, Knemidokoptinae) were identified in affected skin associated with enhanced expression of beak and feather disease virus (BFDV) determined by immunohistochemistry. Also, BFDV antigen was demonstrated in high concentration in the gut and faecal sacs of mites, raising the possibility of ectoparasites as fomites and vectors of BFDV transmission. Large numbers of Raillietina spp. cestodes were present in the intestines. Within the brain there was a focally extensive region of necrosis and inflammation associated with branching, septate, pigmented hyphae consistent with zygomycete fungal infection. This case highlights the potential immunosuppressive effects of BFDV infection and its potential as a keystone pathogen in the Australian environment. © 2017 Australian Veterinary Association.

Serine Proteases of Parasitic Helminths

PubMed Central

Yang, Yong; Wen, Yun jun; Cai, Ya Nan; Vallée, Isabelle; Boireau, Pascal; Liu, Ming Yuan; Cheng, Shi Peng

2015-01-01

Serine proteases form one of the most important families of enzymes and perform significant functions in a broad range of biological processes, such as intra- and extracellular protein metabolism, digestion, blood coagulation, regulation of development, and fertilization. A number of serine proteases have been identified in parasitic helminths that have putative roles in parasite development and nutrition, host tissues and cell invasion, anticoagulation, and immune evasion. In this review, we described the serine proteases that have been identified in parasitic helminths, including nematodes (Trichinella spiralis, T. pseudospiralis, Trichuris muris, Anisakis simplex, Ascaris suum, Onchocerca volvulus, O. lienalis, Brugia malayi, Ancylostoma caninum, and Steinernema carpocapsae), cestodes (Spirometra mansoni, Echinococcus granulosus, and Schistocephalus solidus), and trematodes (Fasciola hepatica, F. gigantica, and Schistosoma mansoni). Moreover, the possible biological functions of these serine proteases in the endogenous biological phenomena of these parasites and in the host-parasite interaction were also discussed. PMID:25748703

Checklists of Parasites of Farm Fishes of Babylon Province, Iraq

PubMed Central

Al-Rubaie, Abdul-Razzak L.

2016-01-01

Literature reviews of all references concerning the parasitic fauna of fishes in fish farms of Babylon province, middle of Iraq, showed that a total of 92 valid parasite species are so far known from the common carp (Cyprinus carpio), the grass carp (Ctenopharyngodon idella), and the silver carp (Hypophthalmichthys molitrix) as well as from three freshwater fish species (Carassius auratus, Liza abu, and Heteropneustes fossilis) which were found in some fish farms of the same province. The parasitic fauna included one mastigophoran, three apicomplexans, 13 ciliophorans, five myxozoans, five trematodes, 45 monogeneans, five cestodes, three nematodes, two acanthocephalans, nine arthropods, and one mollusc. The common carp was found to harbour 81 species of parasites, the grass carp 30 species, the silver carp 28 species, L. abu 13 species, C. auratus one species, and H. fossilis one species. A host-parasite list for each fish species was also provided. PMID:27559480

The Echinococcus canadensis (G7) genome: a key knowledge of parasitic platyhelminth human diseases.

PubMed

Maldonado, Lucas L; Assis, Juliana; Araújo, Flávio M Gomes; Salim, Anna C M; Macchiaroli, Natalia; Cucher, Marcela; Camicia, Federico; Fox, Adolfo; Rosenzvit, Mara; Oliveira, Guilherme; Kamenetzky, Laura

2017-02-27

The parasite Echinococcus canadensis (G7) (phylum Platyhelminthes, class Cestoda) is one of the causative agents of echinococcosis. Echinococcosis is a worldwide chronic zoonosis affecting humans as well as domestic and wild mammals, which has been reported as a prioritized neglected disease by the World Health Organisation. No genomic data, comparative genomic analyses or efficient therapeutic and diagnostic tools are available for this severe disease. The information presented in this study will help to understand the peculiar biological characters and to design species-specific control tools. We sequenced, assembled and annotated the 115-Mb genome of E. canadensis (G7). Comparative genomic analyses using whole genome data of three Echinococcus species not only confirmed the status of E. canadensis (G7) as a separate species but also demonstrated a high nucleotide sequences divergence in relation to E. granulosus (G1). The E. canadensis (G7) genome contains 11,449 genes with a core set of 881 orthologs shared among five cestode species. Comparative genomics revealed that there are more single nucleotide polymorphisms (SNPs) between E. canadensis (G7) and E. granulosus (G1) than between E. canadensis (G7) and E. multilocularis. This result was unexpected since E. canadensis (G7) and E. granulosus (G1) were considered to belong to the species complex E. granulosus sensu lato. We described SNPs in known drug targets and metabolism genes in the E. canadensis (G7) genome. Regarding gene regulation, we analysed three particular features: CpG island distribution along the three Echinococcus genomes, DNA methylation system and small RNA pathway. The results suggest the occurrence of yet unknown gene regulation mechanisms in Echinococcus. This is the first work that addresses Echinococcus comparative genomics. The resources presented here will promote the study of mechanisms of parasite development as well as new tools for drug discovery. The availability of a high-quality genome assembly is critical for fully exploring the biology of a pathogenic organism. The E. canadensis (G7) genome presented in this study provides a unique opportunity to address the genetic diversity among the genus Echinococcus and its particular developmental features. At present, there is no unequivocal taxonomic classification of Echinococcus species; however, the genome-wide SNPs analysis performed here revealed the phylogenetic distance among these three Echinococcus species. Additional cestode genomes need to be sequenced to be able to resolve their phylogeny.

Functional Role of Native and Invasive Filter-Feeders, and the Effect of Parasites: Learning from Hypersaline Ecosystems.

PubMed

Sánchez, Marta I; Paredes, Irene; Lebouvier, Marion; Green, Andy J

2016-01-01

Filter-feeding organisms are often keystone species with a major influence on the dynamics of aquatic ecosystems. Studies of filtering rates in such taxa are therefore vital in order to understand ecosystem functioning and the impact of natural and anthropogenic stressors such as parasites, climate warming and invasive species. Brine shrimps Artemia spp. are the dominant grazers in hypersaline systems and are a good example of such keystone taxa. Hypersaline ecosystems are relatively simplified environments compared with much more complex freshwater and marine ecosystems, making them suitable model systems to address these questions. The aim of this study was to compare feeding rates at different salinities and temperatures between clonal A. parthenogenetica (native to Eurasia and Africa) and the invasive American brine shrimp A. franciscana, which is excluding native Artemia from many localities. We considered how differences observed in laboratory experiments upscale at the ecosystem level across both spatial and temporal scales (as indicated by chlorophyll-a concentration and turbidity). In laboratory experiments, feeding rates increased at higher temperatures and salinities in both Artemia species and sexes, whilst A. franciscana consistently fed at higher rates. A field study of temporal dynamics revealed significantly higher concentrations of chlorophyll-a in sites occupied by A. parthenogenetica, supporting our experimental findings. Artemia parthenogenetica density and biomass were negatively correlated with chlorophyll-a concentration at the spatial scale. We also tested the effect of cestode parasites, which are highly prevalent in native Artemia but much rarer in the invasive species. The cestodes Flamingolepis liguloides and Anomotaenia tringae decreased feeding rates in native Artemia, whilst Confluaria podicipina had no significant effect. Total parasite prevalence was positively correlated with turbidity. Overall, parasites are likely to reduce feeding rates in the field, and their negative impact on host fecundity is likely to exacerbate the difference between grazing rates of native and alien Artemia populations at the ecosystem level. The results of this study provide evidence for the first time that the replacement of native Artemia by A. franciscana may have major consequences for the functioning of hypersaline ecosystems. The strong effect of parasites on feeding rate underlines the importance of taking parasites into account in order to improve our understanding of the functioning of aquatic ecosystems.

Pathology Associated with White Spot Virus (WSV) Infection in Wild Broodstock of Tiger Prawns (Penaeus monodon)

PubMed Central

Kua, Beng Chu; Rashid, Noraziah Mat

2012-01-01

A total of six wild broodstocks of tiger prawns, Penaeus monodon, were found positive for White Spot Virus (WSV) with an IQ2000 detection kit. Using histopathology, the intranuclear inclusion of haemocyte due to WSV infection was observed in the epithelium cells of the antennal gland, stomach and gills. This result confirmed that the wild broodstocks were positive with WSV without showing any white spot. Additionally, histopathological examination also revealed an accumulation of haemocytes around the hepatopancreatic tubules resulting from bacterial infection. Encapsulation and nodule formation, as well as related necrosis, were also observed around the hepatopancreatic tubules infected with a metazoan parasite. Encysted tylocephalum larval cestodes were observed in the hepatopancreas, with haemocytic aggregation being observed around the infected tubules. These findings showed some bacterial and parasitic infections which, in addition to the viral infection itself, could contribute to the 80% mortality rate in wild broodstocks infected with WSV. PMID:24575228

Zoonotic helminth infections with particular emphasis on fasciolosis and other trematodiases

PubMed Central

Robinson, Mark W.; Dalton, John P.

2009-01-01

Zoonotic infections are among the most common on earth and are responsible for >60 per cent of all human infectious diseases. Some of the most important and well-known human zoonoses are caused by worm or helminth parasites, including species of nematodes (trichinellosis), cestodes (cysticercosis, echinococcosis) and trematodes (schistosomiasis). However, along with social, epidemiological and environmental changes, together with improvements in our ability to diagnose helminth infections, several neglected parasite species are now fast-becoming recognized as important zoonotic diseases of humans, e.g. anasakiasis, several fish-borne trematodiasis and fasciolosis. In the present review, we discuss the current disease status of these primary helminth zoonotic infections with particular emphasis on their diagnosis and control. Advances in molecular biology, proteomics and the release of helminth genome-sequencing project data are revolutionizing parasitology research. The use of these powerful experimental approaches, and their potential benefits to helminth biology are also discussed in relation to the future control of helminth infections of animals and humans. PMID:19687044

A new data management system for the French National Registry of human alveolar echinococcosis cases.

PubMed

Charbonnier, Amandine; Knapp, Jenny; Demonmerot, Florent; Bresson-Hadni, Solange; Raoul, Francis; Grenouillet, Frédéric; Millon, Laurence; Vuitton, Dominique Angèle; Damy, Sylvie

2014-01-01

Alveolar echinococcosis (AE) is an endemic zoonosis in France due to the cestode Echinococcus multilocularis. The French National Reference Centre for Alveolar Echinococcosis (CNR-EA), connected to the FrancEchino network, is responsible for recording all AE cases diagnosed in France. Administrative, epidemiological and medical information on the French AE cases may currently be considered exhaustive only on the diagnosis time. To constitute a reference data set, an information system (IS) was developed thanks to a relational database management system (MySQL language). The current data set will evolve towards a dynamic surveillance system, including follow-up data (e.g. imaging, serology) and will be connected to environmental and parasitological data relative to E. multilocularis to better understand the pathogen transmission pathway. A particularly important goal is the possible interoperability of the IS with similar European and other databases abroad; this new IS could play a supporting role in the creation of new AE registries. © A. Charbonnier et al., published by EDP Sciences, 2014.

Canine echinococcosis in northern Jordan: increased prevalence and dominance of sheep/dog strain.

PubMed

Al-Qaoud, Khaled M; Abdel-Hafez, Sami K; Craig, Philip S

2003-06-01

A total of 112 stray and semi-stray dogs (Canis familiaris) from four different geographical areas in northern and middle Jordan were necropsied to evaluate the prevalence and intensity of intestinal helminthiasis. Of these, 33 dogs (29.5%) were infected with Echinococcus granulosus and 61 (54.5%) with other Taenia species. Other cestodes found included Dipylidium caninum in 36 dogs (32.1%), Diplopylidium in 6 dogs (5.4%), Mesocestoides sp. in 3 dogs (2.7%) and Joyuexiella in 1 dog (0.9%). Toxocara nematodes were found in 10 dogs (9.2%) and only 1 dog was positive for acanthocephalans. Among the dogs infected with E. granulosus, 8 dogs (24.2%) had a worm load higher than 1,000 worms. The ratio of infected male to female dogs was 1.9:1.0. Strain analysis of E. granulosus using random primers revealed the dominance of the G1 strain (sheep/dog strain) in the region. Only one dog harbored another E. granulosus strain, which resembled the G4 strain pattern.

A new data management system for the French National Registry of human alveolar echinococcosis cases

PubMed Central

Charbonnier, Amandine; Knapp, Jenny; Demonmerot, Florent; Bresson-Hadni, Solange; Raoul, Francis; Grenouillet, Frédéric; Millon, Laurence; Vuitton, Dominique Angèle; Damy, Sylvie

2014-01-01

Alveolar echinococcosis (AE) is an endemic zoonosis in France due to the cestode Echinococcus multilocularis. The French National Reference Centre for Alveolar Echinococcosis (CNR-EA), connected to the FrancEchino network, is responsible for recording all AE cases diagnosed in France. Administrative, epidemiological and medical information on the French AE cases may currently be considered exhaustive only on the diagnosis time. To constitute a reference data set, an information system (IS) was developed thanks to a relational database management system (MySQL language). The current data set will evolve towards a dynamic surveillance system, including follow-up data (e.g. imaging, serology) and will be connected to environmental and parasitological data relative to E. multilocularis to better understand the pathogen transmission pathway. A particularly important goal is the possible interoperability of the IS with similar European and other databases abroad; this new IS could play a supporting role in the creation of new AE registries. PMID:25526544

[Helminth burden of slaughter sheep in Upper Bavaria. 1: Species spectrum, infestation extent and infestation intensity].

PubMed

Rehbein, S; Kollmannsberger, M; Visser, M; Winter, R

1996-05-01

The helminth fauna of 136 slaughtered sheep (99 lambs < 1 year, and 37 sheep > or = 1 year) from Upper Bavaria, Germany, was examined. In all 2 species of trematodes, 3 species of cestodes and 24 species of nematodes were found. All the animals harboured gastrointestinal nematodes, 9 of them liver flukes, 33 Moniezia spp., 19 Cysticercus tenuicollis, and one sheep Setaria sp. Lungworms were not seen. The most prevalent species were Cooperia curticei (74.3%), Trichuris ovis (69.1%), Ostertagia circumcincta (68.4%), Oesophagostomum venulosum (63.2%) and Chabertia ovina (61.8%). The highest mean wormburden was seen in Cooperia curticei (12471) followed by Trichostrongylus axei (1856), Trichostrongylus colubriformis (1752), Nematodirus filicollis (1551) and Nematodirus battus (1238). In both lambs and older sheep the small intestine harboured the highest wormburden followed by abomasum and large intestine. The total nematode counts were much higher in lambs than in older sheep. The lambs harboured more intestinal nematodes than older sheep but fewer abomasal worms.

Helminth parasites of the raccoon (Procyon lotor) from north-central Arkansas.

PubMed

Richardson, D J; Owen, W B; Snyder, D E

1992-02-01

Twenty-three species of helminths (4 trematodes, 2 cestodes, 14 nematodes, and 3 acanthocephalans) were found in the gastrointestinal tract, lungs, pancreas, tongue, urinary bladder, and subcutaneous tissues of 30 live-trapped or hunter-shot raccoons from north-central Arkansas between November 1989 and April 1990. Helminths were not detected in the brain, diaphragm, gallbladder, heart, liver, reproductive system, or trachea. Each raccoon examined was infected with 3 or more of the following helminths: Brachylaima virginiana, Eurytrema procyonis, Fibricola cratera, Pharyngostomoides procyonis, Atriotaenia procyonis, Mesocestoides spp., Arthrocephalus lotoris, Capillaria aerophila, Capillaria plica, Capillaria procyonis, Capillaria putorii, Crenosoma goblei, Cruzia americana, Dirofilaria tenuis, Dracunculus insignis, Enterobius sp., Gnathostoma procyonis, Molineus barbatus, Physaloptera rara, Trichinella spiralis, Centrorhynchus wardae, Macracanthorhynchus ingens, and Oligacanthorhynchus tortuosa. All helminths collected with the exception of D. insignis constitute new geographic distribution records. Occurrences of C. aerophila, C. wardae, and O. tortuosa are new host records. One nymphal pentastome, Porocephalus crotali, was found in the liver of 1 raccoon, constituting a new host record.

Rapid Molecular Identification of Human Taeniid Cestodes by Pyrosequencing Approach

PubMed Central

Thanchomnang, Tongjit; Tantrawatpan, Chairat; Intapan, Pewpan M.; Sanpool, Oranuch; Janwan, Penchom; Lulitanond, Viraphong; Tourtip, Somjintana; Yamasaki, Hiroshi; Maleewong, Wanchai

2014-01-01

Taenia saginata, T. solium, and T. asiatica are causative agents of taeniasis in humans. The difficulty of morphological identification of human taeniids can lead to misdiagnosis or confusion. To overcome this problem, several molecular methods have been developed, but use of these tends to be time-consuming. Here, a rapid and high-throughput pyrosequencing approach was developed for the identification of three human taeniids originating from various countries. Primers targeting the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of the three Taenia species were designed. Variations in a 26-nucleotide target region were used for identification. The reproducibility and accuracy of the pyrosequencing technology was confirmed by Sanger sequencing. This technique will be a valuable tool to distinguish between sympatric human taeniids that occur in Thailand, Asia and Pacific countries. This method could potentially be used for the molecular identification of the taeniid species that might be associated with suspicious cysts and lesions, or cyst residues in humans or livestock at the slaughterhouse. PMID:24945530

First palaeoparasitological record of a dioctophymatid egg in an archaeological sample from Patagonia.

PubMed

Fugassa, Martín H; Gonzalez Olivera, Elvira A; Petrigh, Romina S

2013-10-01

The collection of parasitological information from ancient material requires an exhaustive study of samples. In 2005, cestode and nematode eggs were found in a coprolite sample tentatively assigned to a canid. The sample was obtained from the layer of the archaeological site located in Cerro Casa de Piedra, Santa Cruz Province, Argentina, and dated from 6540±110 years before present. The aim of the present work was to reexamine this fixed sample in order to confirm the presence of these parasites. The palaeoparasitological results support our previous findings. Interestingly, another parasite was also confirmed: a dioctophymatid nematode. Dioctophyma renale has been reported in several modern carnivores in the Southern Hemisphere but in ancient materials, it has only been reported in human coprolites from Switzerland. This report constitutes the first evidence of the presence of a dioctophymatid nematode parasite dioctophymatid nematode in American pre-Columbian times. The results obtained in this work show the importance of revising earlier palaeoparasitological results. Copyright © 2013 Elsevier B.V. All rights reserved.

Helminth parasites of Natal long-fingered bats, Miniopterus natalensis (Chiroptera: Miniopteridae), South Africa.

PubMed

Junker, K; Bain, O; Boomker, J

2008-09-01

The helminth community infecting Miniopterus natalensis was studied at two localities, the De Hoop Nature Reserve (DHNR) (n = 57), Western Cape Province and Pretoria (n = 12), Gauteng Province, South Africa. Hosts from the DHNR had formed part of an earlier, unrelated study and were all pregnant females. A single hymenolepidid cestode species, the nematodes Molinostrongylus ornatus and Litomosa chiropterorum together with nematodes of the subfamily Capillariinae were present at both study sites, while a single digenean, Allassogonoporus sp., was only found in hosts from the DHNR. The prevalence of helminth infections was high at both localities, 68.4% in the DHNR and 77.7% in Pretoria, whereas the mean intensity of infection was low at the DHNR (3.76 +/- 3.15), but higher in Pretoria (10.4 +/- 9.9). Molinostrongylus ornatus and, to a lesser extent L. chiropterorum, were the main contributors to the higher intensities in Pretoria. The species richness ranged from 0 to 4 at both localities.

Wild rabbit host and some parasites show trophic-level relationships for delta 13C and delta 15N: a first report.

PubMed

Boag, B; Neilson, R; Robinson, D; Scrimgeour, C M; Handley, L L

1998-01-01

We report the first isotopic study of an animal host-parasite system. Parasitic, intestinal nematodes, Graphidium strigosum and Passalurus ambiguus, were 15N-enriched relative to their host, the European rabbit Oryctolagus cuniculus, while parasitic cestodes, Cittataenia denticulata and Mosgovoyia pectinata, were 15N-depleted, suggesting different trophic relationships. Host embryos were more similar in their delta 13C and delta 15N values to maternal muscle than were any of the parasites. Coprophagy, the direct recycling of food by the rabbit eating its own faeces, did not lead to isotopic differences between stomach contents and faeces, suggesting that the major point for isotopic discrimination in lagomorph nitrogen metabolism is in the animal rather than in the gut. We conclude that bulk delta 13C and delta 15N can reveal valuable new information about host-parasite relationships, and these could be explored further at the biochemical level using compound-specific isotopic analyses.

What is Asian Taenia?

PubMed

Eom, Keeseon S

2006-01-01

Asian Taenia is a human tapeworm which was first recognized in Taiwan aborigines and subsequently from Asian countries: Korea, Indonesia, Vietnam, and China. It was originally described as T. asiatica Eom and Rim, 1993 based on the morphology in its adult and larval stage. A taxonomic disagreement on whether it is species or subspecies level is mainly due to the morphological similarity of this tapeworm with T. saginata, but a sympatric distribution of these two tapeworms is also known in China. The life cycle is quite distinct from T. saginata in using the pig as intermediate host and parasitizing visceral organs such as liver, lung and omentum. A long unresolved question in Asian countries concerns the inconsistency between worm ratio and the food preferences was clarified with this viscerotropic tapeworm. Molecular biological differentiation is possible with DNA techniques and a complete genome of mtDNA was sequenced recently which may provide a resource for comparative mitochondrial genomics and systematic studies of parasitic cestodes. This is a young parasite discovered most recently with many research questions yet to be clarified.

The diagnosis of Echinococcus granulosus in dogs.

PubMed

Varcasia, A; Garippa, G; Scala, A

2004-12-01

The problem of diagnosing Echinococcus granulosus in dogs has still only been partially resolved, even after the advent of biotechnology. The eggs of taeniid Cestoda are extremely similar, and thus identification by microscopic examination of the faeces is risky and non-specific. For this reason, Echinococcus granulosus was traditionally diagnosed in dogs ante mortem after an arecoline hydrobromate purge. The faeces were examined macro and microscopically to establish if the adult tapeworm or its proglottids were present. Although this method is 100% specific, it is bio-hazardous and time-consuming, requires trained personnel, and its sensitivity varies. In the 1990s copro-antigens were discovered and characterised. These are released by the adult worm in the faeces. This made it possible to use enzyme-linked immune-adsorbent assay (ELISA) for in vitam diagnosis of Echinococcus granulosus. In recent years several PCR protocols have been published on the identification of Echinococcus granulosus DNA from eggs or from adult parasites and new ways of diagnosing this cestode have been developed.

Two new species of Macrobothridium (Cestoda: Diphyllidea) from rhinobatid elasmobranchs in the Gulf of Gabès, Tunisia, with notes on the status of the genus.

PubMed

Neifar, L; Tyler, G A; Euzet, L

2001-06-01

As a result of an investigation of metazoan parasites of elasmobranch fishes in the Gulf of Gabès, Tunisia, we discovered 2 new species of diphyllidean cestodes. Macrobothridium euterpes n. sp. is described from the spiral intestine of Rhinobatos rhinobatos, and Macrobothridium syrtensis n. sp. from the spiral intestine of Rhinobatos cemiculus. Macrobothridium euterpes is distinguished from the only other species in the genus (Macrobothridium rhynchobati) by the number of rostellar hooks, size, genital pore position, vagina position, and ovary shape. Macrobothridium syrtensis is distinguished from M. rhynchobati by the hook morphology, testis number, and overall size, and from M. euterpes by the number of rostellar hooks, testis number, genital pore position, vagina position, and ovary shape. These are the first 2 species added to the genus since its establishment in 1989. A standardized formula for representing the number and arrangement of rostellar hooks in diphyllidean species is presented.

Immunoregulation by Taenia crassiceps and its antigens.

PubMed

Peón, Alberto N; Espinoza-Jiménez, Arlett; Terrazas, Luis I

2013-01-01

Taenia crassiceps is a cestode parasite of rodents (in its larval stage) and canids (in its adult stage) that can also parasitize immunocompromised humans. We have studied the immune response elicited by this helminth and its antigens in mice and human cells, and have discovered that they have a strong capacity to induce chronic Th2-type responses that are primarily characterized by high levels of Th2 cytokines, low proliferative responses in lymphocytes, an immature and LPS-tolerogenic profile in dendritic cells, the recruitment of myeloid-derived suppressor cells and, specially, alternatively activated macrophages. We also have utilized the immunoregulatory capabilities of this helminth to successfully modulate autoimmune responses and the outcome of other infectious diseases. In the present paper, we review the work of others and ourselves with regard to the immune response induced by T. crassiceps and its antigens, and we compare the advances in our understanding of this parasitic infection model with the knowledge that has been obtained from other selected models.

On the move? Echinococcus multilocularis in red foxes of Saxony-Anhalt (Germany).

PubMed

Denzin, N; Schliephake, A; Fröhlich, A; Ziller, M; Conraths, F J

2014-06-01

Echinococcus multilocularis is a cestode parasites that frequently occurs in the red fox (Vulpes vulpes), which is the main definitive host in Central Europe. The parasite may infect humans as accidental intermediate hosts and cause alveolar echinococcosis. In the German federal state of Saxony-Anhalt, the occurrence of E. multilocularis in red foxes as a possible source of infection for humans was studied from 1998 to 2010. A significant shift in the geographical centroid of the occurrence of E. multilocularis from a long-known highly endemic area in the southwest of the state towards the north-northeast (3.2 km/year) was found. The overall prevalence in the state increased significantly from 13.6% (1998-2005) to 23.4% (2006-2010). No autochthonous cases of alveolar echinococcosis have been reported to date in Saxony-Anhalt, but this might change in the near future with the spread and increasing biomass of the parasite. © 2012 Blackwell Verlag GmbH.

Molecular characterization and detection of variants of Taenia multiceps in sheep in Turkey.

PubMed

Sonmez, Betul; Koroglu, Ergun; Simsek, Sami

2017-02-01

Taenia multiceps is a cestode (family Taeniidae) that in its adult stage lives in the small intestine of dogs and other canids. The metacestode, known as Coenurus cerebralis, is usually found in the central nervous system including brain and spinal card in sheep and other ruminants. The presence of cysts typically leads to neurological symptoms that in the majority of cases result in the death of the animal. Coenurosis could cause high losses in sheep farms because the disease commonly affects young animals. A total of 20 C. cerebralis isolates collected from naturally infected sheep in Mardin province of Turkey were characterized through the polymerase chain reaction and sequencing of a fragment of cytochrome c oxidase subunit 1 (CO1) gene. The results showed that the CO1 gene sequences were highly conserved in C. cerebralis isolates. Phylogenetic analysis based on partial CO1 gene sequences revealed that C. cerebralis isolates were composed of three different variants.

Molecular characterization of enolase gene from Taenia multiceps.

PubMed

Li, W H; Qu, Z G; Zhang, N Z; Yue, L; Jia, W Z; Luo, J X; Yin, H; Fu, B Q

2015-10-01

Taenia multiceps is a cestode parasite with its larval stage, known as Coenurus cerebralis, mainly encysts in the central nervous system of sheep and other livestocks. Enolase is a key glycolytic enzyme and represents multifunction in most organisms. In the present study, a 1617bp full-length cDNA encoding enolase was cloned from T. multiceps and designated as TmENO. A putative encoded protein of 433 amino acid residues that exhibited high similarity to helminth parasites. The recombinant TmENO protein (rTmENO) showed the catalytic and plasminogen-binding characteristics after the TmENO was subcloned and expressed in the pET30a(+) vector. The TmENO gene was transcribed during the adult and larval stages and was also identified in both cyst fluid and as a component of the adult worms and the metacestode by western blot analysis. Taken together, our results will facilitate further structural characterization for TmENO and new potential control strategies for T. multiceps. Copyright © 2015 Elsevier Ltd. All rights reserved.

Expression of the Tpanxb1 gene from Taenia pisiformis and its potential diagnostic value by dot-ELISA.

PubMed

Yang, Deying; Chen, Lin; Wu, Xuhang; Zhou, Xuan; Li, Mei; Chen, Zuqin; Nong, Xiang; Gu, Xiaobin; Peng, Xuerong; Yang, Guangyou

2014-04-01

Cysticercosis, caused by the larvae of Taenia pisiformis, is a common disease in rabbits that results in economic losses. To date, there has been limited information available on the early detection of infection by this parasite. This study describes a dot-ELISA method based on an autologous antigen annexin B1 (Tpanxb1). Its potential for serodiagnosis of rabbit cysticercosis was also evaluated. Western blot analysis revealed that the recombinant Tpanxb1 (rTpanxb1) protein could be specifically recognized by rabbit anti-sera. In serum trials, the antibodies could be detected by dot-ELISA using rTpanxb1 at 14 days post-infection. The positive response was present for up to 49 days post-infection. Based on the necropsy results of 169 rabbit samples, the relative sensitivity and specificity of the dot-ELISA were 94.55% and 92.86%, respectively. This study provides a foundation for studying the immunological function of annexin and its application to control Taenia cestodes.

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

PubMed

Miquel, J; Marchand, B

1997-01-01

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.

Complete Sequence of the mitochondrial genome of the tapeworm Hymenolepis diminuta: Gene arrangements indicate that platyhelminths are eutrochozoans

DOE Office of Scientific and Technical Information (OSTI.GOV)

von Nickisch-Rosenegk, Markus; Brown, Wesley M.; Boore, Jeffrey L.

2001-01-01

Using ''long-PCR'' we have amplified in overlapping fragments the complete mitochondrial genome of the tapeworm Hymenolepis diminuta (Platyhelminthes: Cestoda) and determined its 13,900 nucleotide sequence. The gene content is the same as that typically found for animal mitochondrial DNA (mtDNA) except that atp8 appears to be lacking, a condition found previously for several other animals. Despite the small size of this mtDNA, there are two large non-coding regions, one of which contains 13 repeats of a 31 nucleotide sequence and a potential stem-loop structure of 25 base pairs with an 11-member loop. Large potential secondary structures are identified also formore » the non-coding regions of two other cestode mtDNAs. Comparison of the mitochondrial gene arrangement of H. diminuta with those previously published supports a phylogenetic position of flatworms as members of the Eutrochozoa, rather than being basal to either a clade of protostomes or a clade of coelomates.« less

A review of the global prevalence, molecular epidemiology and economics of cystic echinococcosis in production animals.

PubMed

Cardona, Guillermo A; Carmena, David

2013-02-18

Cystic echinococcosis (CE) is an important and widespread zoonotic infection caused by the larval stages of taeniid cestodes of the genus Echinococcus. The disease represents a serious animal health concern in many rural areas of the world, causing important economic losses derived from decreased productivity and viscera condemnation in livestock species. In this review we aim to provide a comprehensive overview on recent research progress in the epidemiology of CE in production animals from a global perspective. Particular attention has been paid to the discussion of the extent and significance of recent molecular epidemiologic data. The financial burden associated to CE on the livestock industry has also been addressed. Data presented are expected to improve our current understanding of the parasite's geographical distribution, transmission, host range, immunogenicity, pathogenesis, and genotype frequencies. This information should be also valuable for the design and implementation of more efficient control strategies against CE. Copyright © 2012 Elsevier B.V. All rights reserved.

Reef fishes have higher parasite richness at unfished Palmyra Atoll compared to fished Kiritimati Island

USGS Publications Warehouse

Lafferty, Kevin D.; Shaw, Jenny C.; Kuris, Armand M.

2008-01-01

We compared parasite communities at two coral atolls in the Line Islands chain of the central Pacific (Kiritimati Island and Palmyra Atoll). Palmyra Atoll is relatively pristine while Kiritimati Island is heavily fished. At each island, we sampled five fish species for helminth and arthropod endoparasites: Chromis margaritifer, Plectroglyphidodon dickii,Paracirrhites arcatus, Acanthurus nigricans, and Lutjanus bohar. The surveys found monogeneans, digeneans, cestodes, nematodes, acanthocephalans, and copepods. Parasite richness was higher at Palmyra compared to Kiritimati for all five fish species. Fishes from Palmyra also tended to have more parasites species per host, higher parasite prevalence, and higher parasite abundance than did fishes from Kiritimati. The lower parasitism at Kiritimati may result from a simplified food web due to over fishing. Low biodiversity could impair parasite transmission by reducing the availability of hosts required by parasites with complex life cycles. Most notably, the lower abundances of larval shark tapeworms at Kiritimati presumably reflect the fact that fishing has greatly depleted sharks there in comparison to Palmyra.

Survey of intestinal helminths collected from pet rodents in México.

PubMed

Panti-May, Jesús Alonso; Caraveo-Centeno, Luis; Hernández-Betancourt, Silvia F; Robles, María Del Rosario; Machain-Williams, Carlos

2017-11-01

In this survey, intestinal helminths from pet rodents in Mérida, México, were analyzed. A total of 46 mice Mus musculus, 28 hamsters Mesocricetus auratus, 23 rats Rattus norvegicus, and 1 gerbil Meriones unguiculatus were purchased from six pet shops and one black market for wildlife in the city of Mérida. The overall prevalence of helminths in rodents was 61.2% (60/98). Six species of helminths were identified: the zoonotic cestode Rodentolepis nana, and the nematodes Aspiculuris tetraptera, Dentostomella translucida, Syphacia obvelata, Syphacia mesocriceti, and Syphacia muris. Of the 60 infected rodents, 25 (41.7%) harbored 2 or 3 species of helminths. Rodentolepis nana was found in 4.3% of mice and 17.9% of hamsters. This is the first report of infection with S. muris in pet rats. Considering the close physical contact between pet rodents and humans, the presence of R. nana in pets represents a potential risk of transmission, especially to children and immunocompromised individuals.

Hydatid cyst of parotid: Report of unusual cytological findings extending the cytomorphological spectrum.

PubMed

Arora, Vinod Kumar; Chopra, Neha; Singh, Poorva; Venugopal, Vasantha Kumar; Narang, Salil

2016-09-01

Hydatid disease is a zoonotic infestation caused by larval cestode of genus Echinococcus. Cystic form of this infection mostly involves liver and lung. Hydatid disease of the parotid gland is very rare even in endemic areas and is often clinically mistaken for parotid tumors or cysts. The presence of protoscolices, laminated membranes, and isolated hooklets are characteristic cytological features observed on fine-needle aspirate from hydatid cysts. We report unusual cytological features from a hydatid cyst of parotid in a 13-year-old girl. She presented with a slowly enlarging hard mass in left parotid. Fine-needle aspiration yielded slightly turbid fluid. Smears from the sediment revealed naked parasitic micronuclei, fragments of germinative layer (endocyst), and abortive brood capsules (buds from endocyst) seen as spherical structures with multiple parasitic nuclei. Some of these spherical structures were degenerated with recognizable nuclei and others were completely necrotic. Diagn. Cytopathol. 2016;44:770-773. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Medicinal plants: a source of anti-parasitic secondary metabolites.

PubMed

Wink, Michael

2012-10-31

This review summarizes human infections caused by endoparasites, including protozoa, nematodes, trematodes, and cestodes, which affect more than 30% of the human population, and medicinal plants of potential use in their treatment. Because vaccinations do not work in most instances and the parasites have sometimes become resistant to the available synthetic therapeutics, it is important to search for alternative sources of anti-parasitic drugs. Plants produce a high diversity of secondary metabolites with interesting biological activities, such as cytotoxic, anti-parasitic and anti-microbial properties. These drugs often interfere with central targets in parasites, such as DNA (intercalation, alkylation), membrane integrity, microtubules and neuronal signal transduction. Plant extracts and isolated secondary metabolites which can inhibit protozoan parasites, such as Plasmodium, Trypanosoma, Leishmania, Trichomonas and intestinal worms are discussed. The identified plants and compounds offer a chance to develop new drugs against parasitic diseases. Most of them need to be tested in more detail, especially in animal models and if successful, in clinical trials.

Porcine Cysticercosis: Possible Cross-Reactivity of Taenia hydatigena to GP50 Antigen in the Enzyme-Linked Immunoelectrotransfer Blot Assay.

PubMed

Muro, Claudio; Gomez-Puerta, Luis A; Flecker, Robert H; Gamboa, Ricardo; Barreto, Percy Vilchez; Dorny, Pierre; Tsang, Victor C W; Gilman, Robert H; Gonzalez, Armando E; Garcia, Hector H; O'Neal, Seth E; For The Cysticercosis Working Group In Peru

2017-12-01

The lentil lectin glycoprotein enzyme-linked immunoelectrotransfer blot (LLGP EITB, reported sensitivity 99% and specificity 100%) is used as a serologic marker of exposure to Taenia solium in pigs. However, only a limited number of parasites have been evaluated for cross reactivity. Pigs may host other related cestode infections, including Taenia hydatigena, which have not been formally evaluated for cross-reactions. We investigated a corral in Tumbes, Peru, a region where a cysticercosis elimination demonstration project was completed in 2012. In this corral, 14/19 (73.7%) 6-8-week-old piglets were reactive to GP50 on LLGP EITB, and all had circulating Taenia sp. antigens. From eight necropsied piglets; four were infected with T. hydatigena metacestodes whereas none had evidence of T. solium infection. Two resident dogs were subsequently confirmed to have T. hydatigena taeniasis. These results suggest GP50 cross-reactivity in T. hydatigena- infected pigs, although controlled experimental infection is needed to confirm this hypothesis.

Experimental assessment of the effects of gastrointestinal parasites on offspring quality in chinstrap penguins (Pygoscelis antarctica).

PubMed

Palacios, M J; Valera, F; Barbosa, A

2012-05-01

Parasites reduce host fitness and consequently impose strong selection pressures on their hosts. It has been hypothesized that parasites are scarcer and their overall effect on hosts is weaker at higher latitudes. Although Antarctic birds have relatively low numbers of parasites, their effect on host fitness has rarely been investigated. The effect of helminth parasitism on growth rate was experimentally studied in chinstrap penguin (Pygoscelis antarctica) nestlings. In a total of 22 two-nestling broods, 1 nestling was treated with anthelminthics (for cestodes and nematodes) while its sibling was left as a control. Increased growth rate was predicted in de-wormed nestlings compared to their siblings. As expected, 15 days after treatment, the experimental nestlings had increased body mass more than their siblings. These results show a non-negligible negative effect of helminth parasites on nestling body condition that would presumably affect future survival and thus fitness, and it has been suggested there is a strong relationship between body mass and mortality in chinstrap penguins.

Echinococcus granulosus infection in Spain.

PubMed

Carmena, D; Sánchez-Serrano, L P; Barbero-Martínez, I

2008-04-01

Cystic echinococcosis (CE) caused by the cestode Echinococcus granulosus is an endemic disease in Spain. Although specific control programmes initiated in the 1980s have led to marked reductions in CE infection rates in Spain, the disease still remains an important human and animal health problem in many regions of the country. Human incidence and livestock (including sheep, cattle, pigs and horses) prevalence data were gathered from national epidemiological surveillance information systems and regional institutions for the period 2000-2005. Additionally, data on the prevalence of E. granulosus infection in dogs were obtained from published literature. The most affected regions were those of the North Eastern, Central and Western parts of the country, (Autonomous Regions of Aragon, Castile-La Mancha, Castile-Leon, Extremadura, Navarre and La Rioja), where human CE incidence rates in the range of 1.1-3.4 cases per 10(5) inhabitants coexist with ovine/bovine CE prevalence rates up to 23%. Control programmes of hydatidosis/echinococcosis should be reinforced in these regions to reduce the prevalence of the disease.

Apoptosis as a possible mechanism of infertility in Echinococcus granulosus hydatid cysts.

PubMed

Paredes, R; Jiménez, V; Cabrera, G; Iragüen, D; Galanti, N

2007-04-01

Echinococcus granulosus is a parasitic cestode causing hydatidosis in intermediate hosts (human and herbivorous). Most symptoms of the disease occur by the pressure exerted on viscera by cysts that are formed upon ingestion of the parasite eggs excreted by definitive hosts (canines). Protoscoleces, the developmental form of the parasite infective to definitive hosts, are formed in the germinal nucleated layer of fertile hydatid cysts. For unknown reasons, some cysts are unable to produce protoscoleces (infertile hydatid cysts). In this study, analysis of DNA fragmentation using TUNEL and agarose gel electrophoresis showed higher levels of apoptosis in infertile cysts as compared to fertile cysts. Additionally, caspase 3 was detected both in fertile and infertile cysts; the activity of this enzyme was found to be higher in infertile cysts. We conclude that apoptosis may be involved in hydatid cyst infertility. This is the first report on the presence of programmed cell death in E. granulosus. c 2006 Wiley-Liss, Inc.

Spermatological characters of the pseudophyllidean cestode Bothriocephalus scorpii (Müller, 1776).

PubMed

Levron, Céline; Brunanská, Magdaléna; Poddubnaya, Larisa G

2006-06-01

Spermiogenesis of Bothriocephalus scorpii (Cestoda, Pseudophyllidea) includes an orthogonal development of two flagella, followed by a flagellar rotation and a proximo-distal fusion with the median cytoplasmic process. The fusion occurs at the level of four attachment zones. The presence of dense material in the apical region of the differentiation zone in the early stage of spermiogenesis appears to be a characteristic feature for the Pseudophyllidea. The mature spermatozoon possesses two axonemes of 9+"1" pattern of the Trepaxonemata, nucleus, cortical microtubules, electron-dense granules and crested body. The anterior part of the gamete exhibits a centriole surrounded by electron-dense tubular structures arranged as incomplete spiral. When the crested body disappears, the electron-dense tubular structures are arranged into a ring encircling the axoneme. The electron-dense tubular structures and their arrangement appear to be a specific feature for the clade "Bothriocephalidea". The organization of the posterior extremity of the gamete with the nucleus is described for the first time in the Pseudophyllidea.

Intestinal helminths of capybaras, Hydrochoerus hydrochaeris, from Venezuela.

PubMed

Salas, Viviana; Herrera, Emilio A

2004-10-01

Quantitative parameters of intestinal helminth species and their potential relations to host characteristics in a population of capybaras (Hydrochoerus hydrochaeris) from Venezuela are reported for the first time. The intestines of 40 capybaras were collected during the 1992-annual harvest at Hato El Cedral. Six helminth species were found: 2 cestodes (Monoecocestus macrobursatum, M. hagmanni), 2 nematodes (Viannella hydrochoeri, Protozoophaga obesa), and 2 trematodes (Hippocrepis hippocrepis, Taxorchis schistocotyle). This is the first report for M. macrobursatum in Venezuela. Helminth abundance did not differ between sexes or age classes. Although patterns of distribution for all helminth species were overdispersed, the high prevalence found for all species (over 70%) and the high abundance observed for nematodes made it difficult to assess the effect that these helminths may produce on capybaras. Nevertheless, the negative associations found between the body condition of capybaras and helminth intensity for M. macrobursatum and V. hydrochoeri, might be pointing out potential host population regulatory role for these parasites which require further research.

Seven new Yorkeria species (Cestoda: Tetraphyllidea) from Borneo and Australia and their implications for identification of Chiloscyllium (Elasmobranchii: Orectolobiformes) species.

PubMed

Caira, J N; Jensen, K; Rajan, Chandrika

2007-04-01

New material of Yorkeria Southwell, 1927, collected from Chiloscyllium Müller & Henle species, i.e., bamboo sharks, from Malaysian Borneo and eastern Australia was found to include specimens that appear to be consistent with, and thus allow redescription of, the poorly characterized type of the genus, Yorkeria parva Southwell, 1927, as well as 7 new species of tetraphyllidean cestodes from the genus Yorkeria. Discovered in Borneo were Y. parva and Yorkeria teeveeyi n. sp. from Chiloscyllium indicum (Gmelin), Yorkeria garneri n. sp. from Chiloscyllium hasselti Bleeker, Yorkeria pusillulus n. sp., Yorkeria saliputium n. sp., and Yorkeria yubodohensis n. sp. from Chiloscyllium punctatum Miller & Henle. In Australia, a shark species tentatively identified as Chiloscyllium cf. punctatum was found to host Yorkeria izardi n. sp. and Yorkeria longstaffae n. sp. Three of the new species resemble Yorkeria kelleyae Caira & Tracy, 2002, described from sharks identified as C. punctatum in Thailand, in their possession of medial and lateral hooks that are approximately equal in length. All 3 can be distinguished from Y. kelleyae, however, in their possession of vitelline follicles that are not interrupted at the level of the ovary; they differ from one another in that 1 is hyperapolytic (Y. saliputium n. sp.), and the other 2 possess round (Y. pusillulus n. sp.) versus tapered (Y. longstaffae n. sp.) bothridia. Among species with medial and lateral hooks that are conspicuously unequal in length, only Y. izardi n. sp. possesses bothridia that taper posteriorly and almost completely overlap the cephalic peduncle, stopping just short of its posterior margin. Yorkeria garneri n. sp. is distinctive in its possession of mature proglottids that are only slightly longer than wide, rather than distinctly longer than wide. Particularly notable is Y. teeveeyi n. sp., which bears a stobila on which 2-3 of the subterminal proglottids are consistently more mature than the terminal proglottid. Yorkeria yubodohensis n. sp. most closely resembles Y. parva, differing in the pattern of microtriches seen on its scolex, and also in its possession of relatively fewer proglottids. This brings the total number of Yorkeria species described worldwide to 12. The host associations of these cestodes raise questions about the conspecificity of bamboo shark specimens identified as C. punctatum in Thailand, Borneo, and Australia, since individuals in each of these 3 regions appear to host distinctive, nonoverlapping Yorkeria faunas. A key to the 12 known species of Yorkeria is provided.

Understanding trophic interactions in host-parasite associations using stable isotopes of carbon and nitrogen.

PubMed

Nachev, Milen; Jochmann, Maik A; Walter, Friederike; Wolbert, J Benjamin; Schulte, S Marcel; Schmidt, Torsten C; Sures, Bernd

2017-02-17

Stable isotope analysis of carbon and nitrogen can deliver insights into trophic interactions between organisms. While many studies on free-living organisms are available, the number of those focusing on trophic interactions between hosts and their associated parasites still remains scarce. In some cases information about taxa (e.g. acanthocephalans) is completely missing. Additionally, available data revealed different and occasionally contrasting patterns, depending on the parasite's taxonomic position and its degree of development, which is most probably determined by its feeding strategy (absorption of nutrients through the tegument versus active feeding) and its localization in the host. Using stable isotope analysis of carbon and nitrogen we provided first data on the trophic position of an acanthocephalan species with respect to its fish host. Barbels (Barbus barbus) infected only with adult acanthocephalans Pomphorhynchus laevis as well as fish co-infected with the larval (L4) nematodes Eustrongylides sp. from host body cavity were investigated in order to determine the factors shaping host-parasite trophic interactions. Fish were collected in different seasons, to study also potential isotopic shifts over time, whereas barbels with single infection were obtained in summer and co-infected ones in autumn. Acanthocephalans as absorptive feeders showed lower isotope discrimination values of δ 15 N than the fish host. Results obtained for the acanthocephalans were in line with other parasitic taxa (e.g. cestodes), which exhibit a similar feeding strategy. We assumed that they feed mainly on metabolites, which were reprocessed by the host and are therefore isotopically lighter. In contrast, the nematodes were enriched in the heavier isotope δ 15 N with respect to their host and the acanthocephalans, respectively. As active feeders they feed on tissues and blood in the body cavity of the host and thus showed isotope discrimination patterns resembling those of predators. We also observed seasonal differences in the isotope signatures of fish tissues and acanthocephalans, which were attributed to changes in food composition of the host and to seasonality in the transmission and development of acanthocephalans. This study provided first data on trophic interaction between an acanthocephalan species and its associated host, which support the tendency already described for other taxa with similar nutrition strategy (e.g. cestodes). Actively feeding taxa such as larval Eustrongylides sp., appear to act like predators as it can be seen from their isotope discrimination values. However, future research on additional host-parasite systems and especially on acanthocephalans is needed in order to corroborate these conclusions.

Redescription and Molecular Assessment of Relationships Among Three Species of Echeneibothrium (Rhinebothriidea: Echeneibothriidae) Parasitizing the Yellownose Skate, Dipturus chilensis, in Chile.

PubMed

Bueno, Veronica M; Caira, Janine N

2017-06-01

Much progress has recently been made in revising the taxonomic assignments of genera originally classified in the polyphyletic "Tetraphyllidea." Many of these genera, including Echeneibothrium, were accommodated in the order Rhinebothriidea. However, beyond this larger taxonomic action, little work has been conducted on this genus over the past 50 yr. Consequently, the criteria used for characterizing species of Echeneibothrium have lagged behind those typically used in more modern descriptions of elasmobranch-hosted cestode taxa. A series of collecting trips to Chile to obtain cestodes from the yellownose skate, Dipturus chilensis , provided a unique opportunity to apply modern morphological and molecular methods to investigate the 3 species of Echeneibothrium reported parasitizing this skate, specifically Echeneibothrium megalosoma, Echeneibothrium multiloculatum, and Echeneibothrium williamsi. In addition to redescribing all 3 species, using morphological data from light and scanning electron microscopy, maximum likelihood and bayesian inference phylogenetic analyses of the D1-D3 regions of the 28S rDNA gene were conducted to assess their relationships among other echeneibothriids for which comparable data are available. Sequencing of 59 specimens representing these 3 species of Echeneibothrium allowed us to assess the intra- and interspecific variation in the 28S rDNA gene. The redescriptions use standardized terminology for scolex morphology, proglottid anatomy, and microthrix forms and pattern; they also expand on the original descriptions to include data on scolex size, ovary size, vas deferens and vaginal configurations, testes arrangement, and genital pore position. Our morphological work led to a major reinterpretation of the scolex morphology with the recognition that all 3 species bear an apical bothridial sucker, rather than an apical loculus, prompting emendation of the diagnosis for the family Echeneibothriidae. The presence of a band of spinitriches at the apex of the apical modification of the scolex proper seems to represent an important feature for distinguishing the 2 portions of the myzorhynchus across species. Intraspecific variation ranged from 0 to 7 bp across species and interspecific variation ranged from a low of 39-46 bp between E. williamsi and E. multiloculatum to a high of 61-66 bp between E. multiloculatum and E. megalosoma. Phylogenetic analyses indicate that the 3 species of Echeneibothrium hosted by the yellownose skate are not each other's closest relatives, suggesting multiple colonization events of D. chilensis have occurred. Further phylogenetic investigation is also likely to confirm the status of the genus Pseudanthobothrium as a synonym of Echeneibothrium because its species generally group among members of Echeneibothrium.

Why do Siberian chipmunks Tamias sibiricus (Sciuridae) introduced in French forests acquired so few intestinal helminth species from native sympatric murids?

PubMed

Pisanu, Benoît; Lebailleux, Lise; Chapuis, Jean-Louis

2009-02-01

A lack of newly acquired species partly explains why introduced host species have poor specific parasite diversity. The intestinal helminth community from two native Murid host species, wood mice Apodemus sylvaticus [Murinae] (n=40), bank voles Clethrionomys glareolus [Arvicolinae] (n=42), and an introduced Sciurid, the Siberian chipmunk Tamias sibiricus (n=42), dominant in the rodent communities, was studied from three woody areas in the Ile-de-France region. Native gastrointestinal helminth fauna from mice and voles was formed by 12 taxa: ten nematodes, Aonchotheca murissylvatici, Aonchotheca annulosa, Aspiculuris tetraptera, Eucoleus sp., Heligmosomoides glareoli, Heligmosomoides polygyrus, Mastophorus muris, Syphacia frederici, Syphacia stroma, Trichuris muris, a Cestode and a Trematode. Two helminth taxa were imported by chipmunks from eastern Asia: Brevistriata skrjabini and Strongyloides callosciureus. Only A. annulosa was transferred to chipmunks from the native small rodent community. None of the 82 native murids harbored chipmunk helminths. The developmental ability of helminth according to host phylogenetic relatedness was the main driving force explaining the species composition of the helminth community between these sympatric native and introduced hosts.

Intestinal parasites of the red fox (Vulpes vulpes) in Slovenia.

PubMed

Vergles Rataj, Aleksandra; Posedi, Janez; Zele, Diana; Vengušt, Gorazd

2013-12-01

In the present study, 428 foxes were collected and examined for intestinal helminths using the washing-out method. Parasites were found in 93.2% of the examined animals. The most frequently identified nematodes were Uncinaria stenocephala (58.9%), Toxocara canis (38.3%) and Molineus patens (30.6%). Other nematodes found were Pterygodermatites affinis (4.2%), Capillaria sp. (2.8%), Crenosoma vulpis (2.8%), Toxascaris leonina (2.5%), Trichuris vulpis (0.7%) and Physaloptera sp. (0.2%). Mesocestoides sp. (27.6%) and Taenia crassiceps (22.2%) were the most prevalent cestodes, followed by T. polyacantha (6.5%), Hymenolepis nana (2.1%), T. pisiformis (2.1%) and Dipylidium caninum (1.4%). The study also revealed four trematode species: Rossicotrema donicum (1.6%), Heterophyes heterophyes (1.1%), Metagonimus yokogawai (1.1%), Prohemistomum appendiculatum (0.4%) and two protozoan species: oocysts of Sarcocystis (2.8%) and Isospora (0.4%). This is the first extensive study on the intestinal parasites of the red fox (Vulpes vulpes) in Slovenia. The 2.6% prevalence of Echinococcus multilocularis in the same sample population as investigated herein has been reported previously (Vergles Rataj et al., 2010).

Intestinal Helminth Infections in Feral Cats and a Raccoon Dog on Aphaedo Island, Shinan-gun, with a Special Note on Gymnophalloides seoi Infection in Cats

PubMed Central

Shin, Eun-Hee; Park, Jae-Hwan; Guk, Sang-Mee; Kim, Jae-Lip

2009-01-01

Four feral cats and a raccoon dog purchased from a local collector on Aphaedo Island, Shinan-gun, where human Gymnophalloides seoi infections are known to be prevalent, were examined for their intestinal helminth parasites. From 2 of 4 cats, a total of 310 adult G. seoi specimens were recovered. Other helminths detected in cats included Heterophyes nocens (1,527 specimens), Pygidiopsis summa (131), Stictodora fuscata (4), Acanthotrema felis (2), Spirometra erinacei (15), toxocarids (4), and a hookworm (1). A raccoon dog was found to be infected with a species of echinostome (55), hookworms (7), toxocarids (3), P. summa (3), and S. erinacei (1). No G. seoi was found in the raccoon dog. The results indicate that feral cats and raccoon dogs on Aphaedo are natural definitive hosts for intestinal trematodes and cestodes, including G. seoi, H. nocens, and S. erinacei. It has been first confirmed that cats, a mammalian species other than humans, play the role of a natural definitive host for G. seoi on Aphaedo Island. PMID:19488429

Intestinal helminth infections in feral cats and a raccoon dog on Aphaedo Island, Shinan-gun, with a special note on Gymnophalloides seoi infection in cats.

PubMed

Shin, Eun-Hee; Park, Jae-Hwan; Guk, Sang-Mee; Kim, Jae-Lip; Chai, Jong-Yil

2009-06-01

Four feral cats and a raccoon dog purchased from a local collector on Aphaedo Island, Shinan-gun, where human Gymnophalloides seoi infections are known to be prevalent, were examined for their intestinal helminth parasites. From 2 of 4 cats, a total of 310 adult G. seoi specimens were recovered. Other helminths detected in cats included Heterophyes nocens (1,527 specimens), Pygidiopsis summa (131), Stictodora fuscata (4), Acanthotrema felis (2), Spirometra erinacei (15), toxocarids (4), and a hookworm (1). A raccoon dog was found to be infected with a species of echinostome (55), hookworms (7), toxocarids (3), P. summa (3), and S. erinacei (1). No G. seoi was found in the raccoon dog. The results indicate that feral cats and raccoon dogs on Aphaedo are natural definitive hosts for intestinal trematodes and cestodes, including G. seoi, H. nocens, and S. erinacei. It has been first confirmed that cats, a mammalian species other than humans, play the role of a natural definitive host for G. seoi on Aphaedo Island.

Mammalian gastrointestinal parasites in rainforest remnants of Anamalai Hills, Western Ghats, India.

PubMed

Chakraborty, Debapriyo; Hussain, Shaik; Reddy, D Mahendar; Raut, Sachin; Tiwari, Sunil; Kumar, Vinod; Umapathy, Govindhaswamy

2015-06-01

Habitat fragmentation is postulated to be a major factor influencing infectious disease dynamics in wildlife populations and may also be responsible, at least in part, for the recent spurt in the emergence, or re-emergence, of infectious diseases in humans. The mechanism behind these relationships are poorly understood due to the lack of insights into the interacting local factors and insufficient baseline data in ecological parasitology of wildlife. Here, we studied the gastrointestinal parasites of nonhuman mammalian hosts living in 10 rainforest patches of the Anamalai Tiger Reserve, India. We examined 349 faecal samples of 17 mammalian species and successfully identified 24 gastrointestinal parasite taxa including 1 protozoan, 2 trematode, 3 cestode and 18 nematode taxa. Twenty of these parasites are known parasites of humans. We also found that as much as 73% of all infected samples were infected by multiple parasites. In addition, the smallest and most fragmented forest patches recorded the highest parasite richness; the pattern across fragments, however, seemed to be less straightforward, suggesting potential interplay of local factors.

Parasite assemblages of Australian species of Pseudomys (Rodentia: Muridae: Murinae).

PubMed

Weaver, H J; Smales, L R

2012-02-01

The parasite fauna of many Australian rodents is poorly known. The ectoparasite and helminth faunas of Pseudomys delicatulus, Pseudomys desertor, Pseudomys gracilicaudatus, and Pseudomys hermannsburgensis were determined and compared. In total, 12 species of arthropods, 2 cestodes, and 13 nematodes were found. Species richness of parasites was highest in P. hermannsburgensis and lowest in P. desertor. Despite the sampling effort, the number of parasite species discovered did not reach an asymptote for any of the host species, indicating that the full parasite fauna was not examined. Helminth species richness was highest in the insectivorous P. hermannsburgensis and lower in the obligate herbivores. The structure of parasite component communities was influenced by the social structure of the host species, not surprisingly, with the most highly social species having the highest richness of parasites. Habitat preferences also provided contrast between the helminth component communities, with heligmonellid nematodes occurring in damp woodlands and dominating the parasite fauna of P. gracilicaudatus. Oxyurid nematodes dominated the component communities of the 3 other species, all of which inhabit drier habitats.

Histopathological reactions of the blue shark, Prionace glauca, to postlarvae of Hepatoxylon trichiuri (Cestoda: Trypanorhyncha: Hepatoxylidae) in relationship to scolex morphology.

PubMed

Campbell, R A; Callahan, C

1998-01-01

Postlarvae of the cestode Hepatoxylon trichiuri (Holten, 1802) were found attached to the surface of viscera of Prionace glauca (Linnaeus, 1758) taken from Atlantic coastal waters off the south coast of Massachusetts, USA. Gross anatomy of the attachment site shows a quadripartite rim surrounding a deep pit with holes corresponding to the penetration site of each tentacle. Hyperplasia of the liver capsule into outgrowths at the attachment site conform to the attachment of the bothridia. The cuboidal epithelium of the liver capsule became columnar forming papillary outgrowths, with a dense fibrotic reaction beneath the attachment site and infiltration by leukocytes and pigment containing granulocytic cells. Blood sinusoids beneath the attachment site are greatly enlarged. Postlarvae attached to the surface of the epigonal organs of three blue sharks were not accompanied by reactions. SEM examination of the scolex of H. trichiuri postlarvae revealed fused pairs of bothridia within infolded muscular lateral rims, porose tegument devoid of microtriches and a bilateral plane of symmetry in the tentacular armature.

Diseases and parasites of the sea lamprey, Petromyzon marinus, in the Lake Huron basin

USGS Publications Warehouse

McLain, Alberton L.

1952-01-01

Sea lampreys from the Lake Huron basin carried no external parasites and showed a fairly low degree of infection by internal parasites. The material examined represented three life-history stages of the sea lamprey. Recently transformed downstream migrants (215 specimens) harbored only nematodes belonging to the genus Camallanus. The percentage of infection was 2.3. Active feeders from the lake (29 lampreys) revealed the highest degree of parasitism (31.0 percent) with the following parasites present: Echinorhynchus coregoni Linkins; Triaenophorus crassus Forel; and Camallanus sp. Among the 257 sexually mature upstream migrants (14.8 percent infected) Echinorhynchus coregoni and E. leidyi Van Cleave were the most common. Only occasional nematodes and cestodes were found, which fact indicates a failure of the lamprey to carry these parasites to the end of its natural life. Of the parasites observed, only the nematodes gave evidence of serious damage to the host. The study suggests that the role played by parasites in the natural control of the sea lamprey in its new habitat in the upper Great Lakes is of minor importance.

Simultaneous hermaphrodites reproducing in pairs self-fertilize some of their eggs: an experimental test of predictions of mixed-mating and Hermaphrodite's Dilemma theory.

PubMed

Lüscher, A; Milinski, M

2003-09-01

Theory predicts (1) that mixed-mating systems (i.e. reproduction through both selfing and outcrossing) should usually not evolve and (2) that reproducing simultaneous hermaphrodites should be in a conflict over the preferred sexual role (The Hermaphrodite's Dilemma). In an in vitro system with the endoparasitic cestode Schistocephalus solidus, a simultaneous hermaphrodite, we tested predictions of both the mixed-mating and the Hermaphrodite's Dilemma theory. Using microsatellite markers, we measured the proportion of selfed offspring and the total reproductive output of each worm within pairs varying in mean weight and weight difference. Worms produced more outbred offspring not only with increasing total weight of the pair, but also with decreasing weight difference between the two paired worms. These results suggest: (1) that this parasite species reproduces by mixed-mating, which may be maintained by stochastic density fluctuations in the definitive host and hence unpredictability of self reproduction and (2) reproductive conflict may prevent worm pairs from achieving an optimal intermediate selfing rate.

Spermatological characteristics of the genus Taenia inferred from the ultrastructural study on Taenia hydatigena.

PubMed

Miquel, Jordi; Khallaayoune, Khalid; Azzouz-Maache, Samira; Pétavy, Anne-Françoise

2015-01-01

The present study attempts to establish the sperm ultrastructure baseline for Taenia hydatigena, which is essential for the future research on the location of specific proteins involved in spermatogenesis in this species. Thus, the ultrastructural organisation of the mature spermatozoon is described by means of transmission electron microscopy. Live tapeworms were obtained from an experimentally infected dog in the Department of Pathology and Public Health of the Agronomic and Veterinary Institute Hassan II of Rabat (Morocco). The spermatozoon of T. hydatigena is a filiform cell, which is tapered at both extremities and lacks mitochondria. It exhibits all the characteristics of type VII spermatozoon of tapeworms, namely a single axoneme, a crested body, spiralled cortical microtubules and nucleus, a periaxonemal sheath and intracytoplasmic walls. Other interesting characteristics are the presence of a 2000 nm long apical cone in its anterior extremity and only the axoneme in its posterior extremity. The ultrastructural characters of the spermatozoon of T. hydatigena are compared with those of other cestodes studied to date, with particular emphasis on representatives of the genus Taenia.

Fatal infection with Taenia martis metacestodes in a ring-tailed lemur (Lemur catta) living in an Italian zoological garden.

PubMed

De Liberato, Claudio; Berrilli, Federica; Meoli, Roberta; Friedrich, Klaus G; Di Cerbo, Pilar; Cocumelli, Cristiano; Eleni, Claudia

2014-10-01

A case of fatal infection caused by larval forms of Taenia martis in a ring-tailed lemur (Lemur catta) living in the Rome zoological garden is described. The animal, living in a semi-natural pen with other 15 conspecific individuals and being fed with fresh fruit and vegetables, yoghurt and eggs, was transported to the Istituto Zooprofilattico of Rome for post-mortem examination. The anamnesis included, ten days before the death, apathy, lack of appetite, abdominal distension and diarrhoea. A severe exudative fibrinous-purulent peritonitis with numerous adhesions between the abdominal wall and the bowel loops was detected. After intestine removal, two free and viable, 4 cm long, whitish, leaf-like parasitic forms were pinpointed. Macroscopic examination of the two parasites allowed their identification as larval stages of cestodes, identified via molecular analysis as T. martis metacestodes. This report represents the first record of T. martis infection in the host species and in a zoological garden and for the pathological relevance of the infection. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Proteomic analysis of Taenia ovis metacestodes by high performance liquid chromatography-coupled tandem mass spectrometry.

PubMed

Zheng, Yadong

2017-03-15

Taenia ovis metacestodes reside in the muscle of sheep and goats, and may cause great economic loss due to condemnation of carcasses if not effectively controlled. Although advances have been made in the control of T. ovis infection, our knowledge of T. ovis biology is limited. Herein the protein profiling of T. ovis metacestodes was determined by liquid chromatography-linked tandem mass spectrometry. A total of 966 proteins were identified and 25.1% (188/748) were annotated to be associated with metabolic pathways. Consistently, GO analysis returned a metabolic process (16.27%) as one of two main biological process terms. Moreover, it was found that 24 proteins, including very low-density lipoprotein receptor, enolase, paramyosin and endophilin B1, were abundant in T. ovis metacestodes. These proteins may be associated with motility, metabolism, signaling, stress, drug resistance and immune responses. Furthermore, comparative analysis of 5 cestodes revealed the presence of Taenia-specific enolases. These data provide clues for better understanding of T. ovis biology, which is informative for effective control of infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular approaches to Taenia asiatica.

PubMed

Jeon, Hyeong-Kyu; Eom, Keeseon S

2013-02-01

Taenia solium, T. saginata, and T. asiatica are taeniid tapeworms that cause taeniasis in humans and cysticercosis in intermediate host animals. Taeniases remain an important public health concerns in the world. Molecular diagnostic methods using PCR assays have been developed for rapid and accurate detection of human infecting taeniid tapeworms, including the use of sequence-specific DNA probes, PCR-RFLP, and multiplex PCR. More recently, DNA diagnosis using PCR based on histopathological specimens such as 10% formalin-fixed paraffin-embedded and stained sections mounted on slides has been applied to cestode infections. The mitochondrial gene sequence is believed to be a very useful molecular marker for not only studying evolutionary relationships among distantly related taxa, but also for investigating the phylo-biogeography of closely related species. The complete sequence of the human Taenia tapeworms mitochondrial genomes were determined, and its organization and structure were compared to other human-tropic Taenia tapeworms for which complete mitochondrial sequence data were available. The multiplex PCR assay with the Ta4978F, Ts5058F, Tso7421F, and Rev7915 primers will be useful for differential diagnosis, molecular characterization, and epidemiological surveys of human Taenia tapeworms.

Analysis of lead pollution levels within an urban ecosystem using the cestode Hymenolepis diminuta and its rat hosts as bioindicators.

PubMed

Tripodi, M A; Hancke, D; Suarez, O V

2017-10-11

The overall goal of this study was to use the Rattus spp./Hymenolepis diminuta model to assess environmental lead pollution in different landscape units of an urban ecosystem. Rats of the genus Rattus were collected from three shanty towns and three residential neighbourhoods of the city of Buenos Aires. Concentrations of lead in the livers of wild rats and in their parasite H. diminuta were measured using inductively coupled plasma mass spectrometry (ICP-MS). The landscape unit and tissue type had a significant effect on lead concentration, being higher in residential neighbourhoods as well as in H. diminuta tissue. Nevertheless, no significant differences were found for the mean lead concentration in livers between uninfected and infected rats. Since the available information describing heavy-metal pollution within the city of Buenos Aires is scarce, the results of this study allow us to update data about the extent of biologically available lead contamination. Considering that rats and H. diminuta are distributed worldwide, this monitoring system for lead pollution might be applied successfully in other urban ecosystems.

Degradation of azo dyes by environmental microorganisms and helminths

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kingthom Chung; Stevens, S.E. Jr.

1993-11-01

The degradation of azo dyes by environmental microorganisms, fungi, and helminths is reviewed. Azo dyes are used in a wide variety of products and can be found in the effluent of most sewage treatment facilities. Substantial quantities of these dyes have been deposited in the environment, particularly in streams and rivers. Azo dyes were shown to affect microbial activities and microbial population sizes in the sediments and in the water columns of aquatic habitats. Only a few aerobic bacteria have been found to reduce azo dyes under aerobic conditions, and little is known about the process. A substantial number ofmore » anaerobic bacteria capable of azo dye reduction have been reported. The enzyme responsible for azo dye reduction has been partially purified, and characterization of the enzyme is proceeding. The nematode Ascaris lumbricoides and the cestode Moniezia expanza have been reported to reduce azo dyes anaerobically. Recently the fungus Phanerochaete chrysoporium was reported to mineralize azo dyes via a peroxidation-mediated pathway. A possible degradation pathway for the mineralization of azo dye is proposed and future research needs are discussed.« less

Helminth parasites of freshwater fishes from Cuatro Ciénegas, Coahuila, in the Chihuahuan Desert of Mexico: inventory and biogeographical implications.

PubMed

Aguilar-Aguilar, Rogelio; Martínez-Aquino, Andrés; Espinosa-Pérez, Héctor; Pérez-Ponce de León, Gerardo

2014-06-01

As part of an ongoing inventory of the helminth parasites of freshwater fishes in Mexico, 570 individual fish were collected between Apr 2008 and Oct 2011 in 26 localities along the Cuatro Ciénegas region in Coahuila State, northern Mexico. Seventeen species of hosts, mostly corresponding to Nearctic freshwater elements, were studied. A total of 8324 individual worms were collected during this survey, representing 25 species of helminths, of which 9 were digeneans, 3 monogeneans, 3 acanthocephalans, 9 nematodes and 1 cestode. Most of the records in this checklist represent new host or locality records. The information provided in this checklist may be helpful for our understanding of the biodiversity and historical biogeography of this host-parasite system, because in the Cuatro Ciénegas region occur a Nearctic freshwater fish fauna, along with Neotropical and endemic elements, and from a biogeographical point of view, this may represent a transitional area. © 2013 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Fish hepatic glutathione-S-transferase activity is affected by the cestode parasites Schistocephalus solidus and Ligula intestinalis: evidence from field and laboratory studies.

PubMed

Frank, Sabrina Nadine; Faust, Steffen; Kalbe, Martin; Trubiroha, Achim; Kloas, Werner; Sures, Bernd

2011-06-01

The activity of hepatic glutathione-S-transferase (GST) was analysed in 3 different fish species with respect to fish sex and infection with parasites. In both sexes of laboratory bred three-spined sticklebacks (Gasterosteus aculeatus) experimentally infected with Schistocephalus solidus (Cestoda), a significantly lower GST-activity was found for infected fish compared to control. After field sampling of roach (Rutilus rutilus) from Lake Müggelsee (MS) and the Reservoir Listertalsperre (LTS), the GST-activity showed significantly lower values for males infected with Ligula intestinalis from MS (25%) and for infected females from LTS (55%). L. intestinalis-infected female chub (Leuciscus cephalus) from LTS also appeared to have a lower GST-activity. Thus, it could be shown that the presence of parasites significantly affects GST-activity in different fish species resulting in a decreased GST-activity due to infection. Our results therefore emphasize the need for more integrative approaches in environmental pollution research to clearly identify the possible effects of parasites in an effort to develop biomarkers for evaluating environmental health.

Helminth parasites of the leopard frog Lithobates sp. Colima (Amphibia: Ranidae) from Colima, Mexico.

PubMed

Cabrera-Guzmán, Elisa; Garrido-Olvera, Lorena; León-Règagnon, Virginia

2010-08-01

The helminth fauna inhabiting Lithobates sp. Colima from Ticuizitán, Colima, Mexico, comprises 10 species: 4 digeneans ( Clinostomum sp., Glypthelmins quieta , Haematoloechus sp., and Langeronia macrocirra ), 5 nematodes ( Aplectana itzocanensis , Cosmocerca podicipinus , Foleyellides striatus , Oswaldocruzia subauricularis , and Rhabdias sp.), and 1 cestode (Cyclophyllidea). Glypthelmins quieta , L. macrocirra , and A. itzocanensis represent new host records. These observations, added to previous records from Acapulco, Guerrero, Mexico, indicate that the helminth fauna of Lithobates sp. from Colima comprises 25 taxa. Frogs are being parasitized by 3 infection routes: ingestion of intermediate host, skin penetration by larval forms, and transmission by vectors. Species of Aplectana , Cosmocerca , Foleyellides , and Oswaldocruzia occurred in high prevalence in Colima, similar to a previous study on the same frog species from Guerrero. In Colima, Glypthelmins , Haematoloechus , and Rhabdias also occurred in high prevalence. Haematoloechus species reached the highest mean intensity in both localities. The semiaquatic habits of this species of frog and the availability of particular feeding resources appear to determine the helminth composition and infection levels; however, co-speciation events also play an important role structuring these helminth communities.

Prevalence of parasitic contamination of raw vegetables in villages of Qazvin Province, Iran.

PubMed

Shahnazi, Mojtaba; Jafari-Sabet, Majid

2010-09-01

We conducted a study to determine the extent of parasitic contamination of raw vegetables distributed by wholesalers in villages of Qazvin Province, Iran. Vegetables collected for the study were leek, parsley, lettuce, coriander, radish, spring onion, tarragon, basil, spearmint, and cress. Samples of each vegetable were collected at monthly intervals for 6 months from May to October 2008, yielding a total of 654 samples. Samples of each vegetable collected at each monthly interval were selected randomly and allocated to be washed or to remain unwashed before being analyzed for parasitic contamination. Of the 654 samples collected over the study period, 218 samples were analyzed for parasitic contamination without washing and 436 were washed before being analyzed, with the wash procedure consisting of submersion in a solution of 200 ppm of calcium hypochlorite and rinsing in an automated vegetable washer for 10 minutes. The samples were analyzed according to the method used by the U.S. Food and Drug Administration for identifying parasitic contamination of raw fruits and vegetables, with specimens weighing 200 g each being prepared from the vegetable samples, followed by sonication of each specimen for 10 minutes in 1.5 L of detergent wash solution, collection and centrifugation of a 50-mL aliquot of the wash solution for 15 minutes at 1500 g, and examination of the resulting sediment for parasites by light microscopy. No parasitic contamination was found on any of the 436 washed samples of vegetables. Of the 218 unwashed samples of vegetables, 82 (37.6%) were found to be contaminated with parasites, of which 69 (31.6%) were contaminated with metazoa (helminth eggs in 9.6% and rhabditoid larvae in 22.0%), and 13 (6.0%) were contaminated with protozoa (Entamoeba coli cysts in 2.8%, Entamoeba histolytica/E. dispar cysts in 1.4%, and Giardia lamblia cysts in 1.8%). The difference in parasitic contamination of the washed and unwashed groups of vegetables was significant at p < 0.05. Helminth eggs detected in unwashed samples included those of nematodes (Ascaris lumbricoides [2.3%], Trichuris trichiura [0.9%], and Trichostrongylus spp. [2.8%]), trematodes (Dicrocoelium dendriticum [1.4%]), and cestodes (Taenia spp. [1.8%] and Hymenolepis nana [0.5%]). The eggs recovered in greatest number were those of nematodes (n = 13), followed by those of cestodes (n = 5) and trematodes (n = 3). No helminth eggs were found on unwashed samples of spearmint, tarragon, coriander, or radish. The percent parasitic contamination of unwashed samples was highest for leek (66.7%) and lowest for radish (20.7%). The highest percent parasitic contamination was with rhabditoid larvae (22.0%) and the lowest with H. nana eggs (0.5%). These findings emphasize the importance of properly washing and disinfecting raw vegetables before they are consumed.

Gastrointestinal helminths of two populations of wild pigeons (Columba livia) in Brazil.

PubMed

Vaz, Frederico Fontanelli; Silva, Lidiane Aparecida Firmino da; Ferreira, Vivian Lindmayer; Silva, Reinaldo José da; Raso, Tânia Freitas

2017-01-01

The present study analyzed gastrointestinal helminth communities in 265 wild pigeons (Columba livia) living in the municipalities of São Paulo and Tatuí, state of São Paulo, Brazil, over a one-year period. The birds were caught next to grain storage warehouses and were necropsied. A total of 790 parasites comprising one nematode species and one cestode genus were recovered from 110 pigeons, thus yielding an overall prevalence of 41.5%, mean intensity of infection of 7.2 ± 1.6 (range 1-144) and discrepancy index of 0.855. Only 15 pigeons (5.7%) presented mixed infection. The helminths isolated from the birds were Ascaridia columbae (Ascaridiidae) and Raillietina sp. (Davaineidae). The birds' weights differed according to sex but this did not influence the intensity of infection. The overall prevalence and intensity of infection did not differ between the sexes, but the prevalence was higher among the birds from Tatuí (47.8%). The gastrointestinal helminth community of C. livia was characterized in the two areas studied and parasite homogeneity was observed over the 12 months analyzed at both locations. These results make contributions to the current literature on health aspects of wild C. livia populations.

Behavioural and physiological effects of the trophically transmitted cestode parasite, Cyathocephalus truncatus, on its intermediate host, Gammarus pulex.

PubMed

Franceschi, N; Rigaud, T; Moret, Y; Hervant, F; Bollache, L

2007-11-01

Some parasites with complex life-cycles are able to manipulate the behaviour of their intermediate hosts in a way that increases their transmission to the next host. Gammarids infected by the tapeworm Cyathocephalus truncatus (Cestoda: Spathebothriidea) are known to be more predated by fish than uninfected ones, but potential behavioural manipulation by the parasite has never been investigated. In this study, we tested the hypothesis that C. truncatus is able to manipulate the behaviour of one of its intermediate hosts, Gammarus pulex (Crustacea: Amphipoda). To assess if any behavioural change was linked to other phenotypic alterations, we also measured the immunity of infected and uninfected individuals and investigated the pathogenic effects of the parasite. Infected gammarids were significantly less photophobic than uninfected ones, but no effect of infection on the level of immune defence was found. The results on survival, swimming activity and oxygen consumption suggest that the parasite also has various pathogenic effects. However, the alteration in host phototaxis was not correlated to some of these pathogenic effects. Therefore, we propose that the modification in host reaction to light is a behavioural manipulation, explaining the previously observed increase of gammarid predation rate.

Metazoan parasite infracommunities of Florida pompano (Trachinotus carolinus) from the coast of the Yucatan Peninsula, Mexico.

PubMed

Sánchez-Ramírez, Claudia; Vidal-Martínez, Victor M

2002-12-01

Metazoan parasite infracommunities of the Florida pompano (Trachinotus carolinus) were studied in terms of species composition, species richness, diversity, numerical dominance, and similarity. Seventy-five fishes were collected from 4 localities along the Yucatan Peninsula coast and 24 parasite species recovered. Most were digeneans (8 species) and nematodes (7). Other species were monogeneans (3). aspidogastreans (2), cestodes (1), acanthocephalans (1), and crustaceans (2). Only 4 species were common in at least I locality. Mean values for species richness, abundance, diversity, numerical dominance, and similarity in total (all species in the individual fish), gastrointestinal, and ectoparasite infracommunities were within ranges observed for most helminth infracommunities of marine fishes from temperate and tropical latitudes. These infracommunities had low species richness, abundance, diversity, and predictability (except ectoparasite infracommunities) and high dominance. Within the predictable element (common species), the specialist monogenean Pseudobicotylophora atlantica was the main reason for the increase in predictability because it was the only common species at all 4 localities. Host feeding habits, the distribution of intermediate hosts and infective stages, the local species pool, and a phylogenetic component seem to be determining the characteristics of these metazoan parasite infracommunities.

Granulomatous responses in larval taeniid infections.

PubMed

Díaz, Á; Sagasti, C; Casaravilla, C

2018-05-01

Granulomas are responses to persistent nonliving bodies or pathogens, centrally featuring specialized macrophage forms called epithelioid and multinucleated giant cells. The larval stages of the cestode parasites of the Taeniidae family (Taenia, Echinococcus) develop for years in fixed tissue sites in mammals. In consequence, they are targets of granulomatous responses. The information on tissue responses to larval taeniids is fragmented among host and parasite species and scattered over many decades. We attempt to draw an integrated picture of these responses in solid tissues. The intensity of inflammation around live parasites spans a spectrum from minimal to high, parasite vitality correlating with low inflammation. The low end of the inflammatory spectrum features collagen capsules proximal to the parasites and moderate distal infiltration. The middle of the spectrum is dominated by classical granulomatous responses, whereas the high end features massive eosinophil invasions. Across the range of parasite species, much observational evidence suggests that eosinophils are highly effective at killing larval taeniids in solid tissues, before and during chronic granulomatous responses. The evidence available also suggests that these parasites are adapted to inhibit host granulomatous responses, in part through the exacerbation of host regulatory mechanisms including regulatory T cells and TGF-β. © 2018 John Wiley & Sons Ltd.

Helminth communities of Leptodactylus latrans (Anura: Leptodactylidae) from the Atlantic rainforest, south-eastern Brazil.

PubMed

Toledo, G M; Morais, D H; Silva, R J; Anjos, L A

2015-03-01

The helminth fauna associated with Leptodactylus latrans, a large frog living in a disturbed environment of Atlantic rainforest in south-eastern Brazil, was evaluated. We found eight helminth taxa, including five nematode species, Falcaustra mascula, Oswaldocruzia subauricularis, Physaloptera sp., Rhabdias sp. and an unidentified cosmocercid, two trematodes, Gorgoderina parvicava and Haematoloechus fuelleborni, and one larval cestode. The overall prevalence of infection was 63.2% with a mean intensity of 11.3 ± 3.8. The cosmocercid nematode and O. subauricularis showed the highest prevalences, although the trematode G. parvicava was the most abundant and dominant parasite species. Host size positively influenced both the intensity of infection and parasite species richness. Our data suggest that the juvenile individuals of L. latrans are more susceptible to parasitic infection than the adults. The comparison of the similarity of this community component with that found in other studies in South America shows that, as well as the characteristics of the host, the sampling area also influences the parasitic fauna. Therefore, the results of this study agree that the helminth communities of frogs have relatively low species richness and dominance of generalist species.

The influence of geographical location, host maturity and sex on intestinal helminth communities of the double-crested cormorant Phalacrocorax auritus from the eastern United States.

PubMed

Sheehan, K L; Hanson-Dorr, K C; Dorr, B S; Yarrow, G K; Johnson, R J

2017-09-01

Here the intestinal helminth infracommunities of 218 double-crested cormorants (Phalacrocorax auritus) from 11 locations in Alabama, Minnesota, Mississippi and Vermont are documented. Trematode infections were present in 98% of hosts; 65% of cormorants carried cestode infections, 4% were infected with acanthocephalans and 66% had nematode intestinal parasites. Parasite infracommunities of hosts collected on wintering grounds had higher richness and diversity than did birds collected on breeding grounds. Differences in parasite richness and diversity between male and female P. auritus were also detected, but not between immature and mature bird hosts. Parasite intensity did not differ by sex, maturity, or between breeding and wintering season. The most common parasite was Drepanocephalus auritus (spathans), which is recognized as a disease agent that negatively impacts the catfish aquaculture industry in the US. Echinochasmus sp. in double-crested cormorants is documented for the first time in the United States. We suggest that the differences observed among parasite infracommunities could be associated with the foraging distances travelled by P. auritus during breeding and wintering seasons, which is limited by allocation of parental care during the breeding season.

FIRST CASE OF HUMAN INFECTION BY Bertiella studeri (Blanchard, 1891) Stunkard,1940 (Cestoda; Anoplocephalidae) IN BRAZIL

PubMed Central

LOPES, Valeriana Valadares; dos SANTOS, Hudson Andrade; da SILVA, Amália Verônica Mendes; FONTES, Gilberto; VIEIRA, Gabriela Lisboa; FERREIRA, Arilton Carlos; da SILVA, Eduardo Sergio

2015-01-01

SUMMARY Cestodes of the Bertiella genus are parasites of non-human primates found in Africa, Asia, Oceania and the Americas. Species Bertiella studeri and Bertiella mucronata could, accidentally, infect human beings. The infection occurs from ingestion of mites from the Oribatida order containing cysticercoid larvae of the parasite. The objective of this report is to register the first case of human infection by Bertiella studeri in Brazil. Proglottids of the parasite, found in the stool sample of a two-and-a-half-year-old child, were fixed, stained and microscopically observed to evaluate its morphological characteristics. Eggs obtained from the proglottids were also studied. The gravid proglottids examined matched the description of the genus Bertiella. The eggs presented a round shape, with the average diameter of 43.7 µm, clearly showing the typical pyriform apparatus of B. studeri. The authors concluded that the child was infected with Bertiella studeri, based on Stunkard's (1940) description of the species. This is the fifth case of human Bertiellosis described in Brazil through morphometric analysis of the parasite, the third in Minas Gerais State and the first diagnosed case of Bertiella studeri in Brazil. PMID:26603236

[Endoparasitic infections in sheep from the Swabian Alb].

PubMed

Rehbein, S; Visser, M; Winter, R

1998-11-01

The endoparasite fauna of 59 slaughtered sheep (30 lambs, 29 ewes) from the Swabian Alb, Germany, was examined. One species of trematodes, 3 species of cestodes, 29 species of nematodes (23 species of gastro-intestinal and 6 species of lung nematodes), 1 species of arthropodes and 1 species of protozoa were recorded. All animals were infected with Dicrocoelium dentriticum as well as gastro-intestinal and lung nematodes, 45.8% with Moniezia spp., 15.3% with Cysticercus tenuicollis, 55.9% with Oestrus ovis and 11.9% with Sarcocystis gigantea. The most important gastro-intestinal nematodes were Ostertagia circumcincta and Cooperia curticei, which were recorded in all sheep, Ostertagia trifurcata and Chabertia ovine (98.3% each), Oesophagostumum venulosum (96.6%), Nematodirus filicollis (81.4% each), Ostertagia pinnata (78.0%), Trichuris ovis and Trichostrongylus colubriformis (76.3% each). The ewes harboured more abomasal and small intestinal nematodes (1819 and 3702) than the lambs (695 and 1730), which haboured more large intestinal nematodes (177) than those (56). The most often recorded lungworms were Cystocaulus ocreatus (74.6%) and Muellerius capillaris (72.9%), followed by Neostrongylus linearis (57.6%), Dictyocaulus filaria (50.8%), Protostrongylus brevispiculum (37.3%) and Protostrongylus rufescens (28.8%). The ewes carried higher lungworm burdens than the lambs.

Trematodes Recovered in the Small Intestine of Stray Cats in the Republic of Korea

PubMed Central

Chai, Jong-Yil; Bahk, Young Yil

2013-01-01

In 2005, we reported the infection status of 438 stray cats with various species of intestinal helminths, including nematodes (4 species), trematodes (23 species), and cestodes (5 species) in the Republic of Korea. However, morphologic details of each helminth species have not been provided. In the present study, we intended to describe morphologic details of 13 trematode species which were either new fauna of cats (10 species) or new fauna of not only cats but also all animal hosts (3 species). The worms were fixed in 10% neutral buffered formalin under a cover slip pressure, stained with Semichon's acetocarmine, and then observed using a light microscope equipped with a micrometer. The 13 subjected species included members of the Heterophyidae (Stellantchasmus falcatus, Stictodora fuscata, Stictodora lari, Centrocestus armatus, Procerovum varium, and Cryptocotyle concava), Echinostomatidae (Echinostoma hortense, Echinostoma revolutum, Echinochasmus japonicus, and Stephanoprora sp.), Diplostomidae (Neodiplostomum seoulense), Plagiorchiidae (Plagiorchis muris), and Dicrocoeliidae (Eurytrema pancreaticum). By the present study, Cryptocotyle sp. and Neodiplostomum sp. recored in our previous study were identified as C. concava and N. seoulense, respectively. Three species, P. varium, C. concava, and Stephanoprora sp., are new trematode fauna in Korea. PMID:23467726

Dogs, cats, parasites, and humans in Brazil: opening the black box

PubMed Central

2014-01-01

Dogs and cats in Brazil serve as primary hosts for a considerable number of parasites, which may affect their health and wellbeing. These may include endoparasites (e.g., protozoa, cestodes, trematodes, and nematodes) and ectoparasites (i.e., fleas, lice, mites, and ticks). While some dog and cat parasites are highly host-specific (e.g., Aelurostrongylus abstrusus and Felicola subrostratus for cats, and Angiostrongylus vasorum and Trichodectes canis for dogs), others may easily switch to other hosts, including humans. In fact, several dog and cat parasites (e.g., Toxoplasma gondii, Dipylidium caninum, Ancylostoma caninum, Strongyloides stercoralis, and Toxocara canis) are important not only from a veterinary perspective but also from a medical standpoint. In addition, some of them (e.g., Lynxacarus radovskyi on cats and Rangelia vitalii in dogs) are little known to most veterinary practitioners working in Brazil. This article is a compendium on dog and cat parasites in Brazil and a call for a One Health approach towards a better management of some of these parasites, which may potentially affect humans. Practical aspects related to the diagnosis, treatment, and control of parasitic diseases of dogs and cats in Brazil are discussed. PMID:24423244

Ecological aspects of helminth fauna of Magellanic penguins, Spheniscus magellanicus (aves: Spheniscidae), from the Northern Coast of the State of São Paulo, Brazil.

PubMed

Rezende, G C; Baldassin, P; Gallo, H; Silva, R J

2013-02-01

The aim of the present study was to evaluate the helminth fauna found in the Magellanic penguin, Spheniscus magellanicus, relating parasite population and community ecological parameters to life aspects of the host species. The study involved 237 specimens of S. magellanicus taken from the northern shore of the state of São Paulo (23° 46' S, 45° 57' W) and southern shore of the state of Rio de Janeiro (23° 02' S, 44° 13' W), Brazil. The following helminth fauna were found: the nematode Contracaecum pelagicum (core species), found in the stomach; the digenetic Cardiocephaloides physalis and the cestode Tetrabothrius lutzi (satellite species), both collected from the initial portion of the small intestine. Comparisons using the Shannon Diversity Index revealed that the parasite community in juvenile penguins is less diverse in the migratory season than the breeding season. Parasitological studies on penguins and other migratory animals provide important information on species during the time in which they remain pelagic and constitute a useful tool for the acquisition of data that is difficult to obtain through other means, thereby favoring the conservation of the species.

Gryporhynchidae (Cestoda: Cyclophyllidea) in Mexico: species list, hosts, distribution and new records.

PubMed

Ortega-Olivares, Mirza P; García-Prieto, Luis; García-Varela, Martín

2014-05-12

As a result of this study, 8 new host (Botaurus lentiginosus for Glossocercus caribaensis and Valipora mutabilis; Egretta caerulea for Valipora minuta; Egretta thula for Glossocercus cyprinodontis; Egretta tricolor and Nycticorax nycticorax for Glossocercus caribaensis; Pelecanus occidentalis and Platalea ajaja for Paradilepis caballeroi) and 31 new locality records for gryporhynchid cestode species in Mexico are presented. With these data, the total number of species of this group of helminths in Mexico becomes 25 (19 named species and 6 unidentified taxa), which have been registered as parasites of fishes (47 host species) and (or) birds (20 host species). This information comes from 102 localities, pertaining to 20 of 32 Mexican states. Five of the 25 taxa have been exclusivelly collected in fishes, 7 in fish-eating birds, and 13 in both groups of hosts. The most frequent metacestodes found in Mexican fishes are the merocercoids of Cyclustera ralli, Valipora mutabilis, Parvitaenia cochlearii and Valipora campylancristrota; in adult stage, Glossocercus caribaensis was the species with the largest host spectrum, while Paradilepis caballeroi has the widest distribution range. The work includes parasite/host lists, as well as habitat, distribution, references and information on specimens' deposition.

Prevalence and intensity of gastro-intestinal helminths in horses in the Sudano-Guinean climatic zone of Cameroon

PubMed Central

Lem, Mbafor Fidelia; Vincent, Khan Payne; Pone, Josue Wabo; Joseph, Tchoumboue

2012-01-01

Background: It is important to understand the biology and health impact of parasites affecting horses in the Western highlands of Cameroon. Aim: to evaluate the prevalence and intensity of infection of gastrointestinal helminths in these animals. Materials and Methods: A total of 894 horses (367 males and 527 females), and aged ≤1 to ≥7 years old were examined. A parasitological investigation of faeces was carried out using two techniques: concentration method of Full Born Willis (flotation in saturated solution of sodium chloride) and Mc Master Technique. Results and conclusions: From the results the overall prevalence was 100%. Nine species of nematode (Parascaris equorum, Oxyuris equi, Habronema sp., Strongyloides westeri, Dictyocaulus arnfieldi, Trichostrongylus axei, Cyathostome sp., Triodontophorus sp., Strongylus sp.) were identified with the prevalence of 18.48%, 16.94%, 2.99%, 6.05%, 5.22%, 7.75%, 12.49%, 1.09%, and 22.26%, respectively, and one species of cestode (Anoplocephala magna) with a prevalence of 6.73%. Strongylus sp. had the highest mean intensity of infection (1270±942) in female horses. Poly-parasitic infections (92.28%) were more common than mono-parasitic infections (7.72%). PMID:23508513

Inter- and intraspecific conflicts between parasites over host manipulation

PubMed Central

Hafer, Nina; Milinski, Manfred

2016-01-01

Host manipulation is a common strategy by which parasites alter the behaviour of their host to enhance their own fitness. In nature, hosts are usually infected by multiple parasites. This can result in a conflict over host manipulation. Studies of such a conflict in experimentally infected hosts are rare. The cestode Schistocephalus solidus (S) and the nematode Camallanus lacustris (C) use copepods as their first intermediate host. They need to grow for some time inside this host before they are infective and ready to be trophically transmitted to their subsequent fish host. Accordingly, not yet infective parasites manipulate to suppress predation. Infective ones manipulate to enhance predation. We experimentally infected laboratory-bred copepods in a manner that resulted in copepods harbouring (i) an infective C plus a not yet infective C or S, or (ii) an infective S plus a not yet infective C. An infective C completely sabotaged host manipulation by any not yet infective parasite. An infective S partially reduced host manipulation by a not yet infective C. We hence show experimentally that a parasite can reduce or even sabotage host manipulation exerted by a parasite from a different species. PMID:26842574

Endoparasites of the spiny mouse (Acomys spinosissimus) from South Africa.

PubMed

Lutermann, Heike; Medger, Katarina; Junker, Kerstin

2014-02-01

The endoparasite fauna of the spiny mouse (Acomys spinosissimus) was studied for the first time from April 2007 until April 2009 in a population from the Limpopo Province of South Africa. In a total of 129 mice examined, only 6 endoparasite taxa were found, 2 nematode species (Syphacia minuta, Monanema joopi), 1 genus of cestodes ( Rodentolepis spp.), and unidentified hymenolepidid fragments. In addition, 1 pentastomid species (Armillifer grandis) as well as unidentified porocephalid specimens were recovered. The overall prevalence was low, at 15.5%, and only 1 individual harbored more than 1 parasite species. With 12.4% prevalence, S. minuta was the most prevalent parasite. Its prevalence and abundance were significantly higher during the dry and cooler season than during the wet and warm season, while a female-biased burden was observed during the wet season only. For the remaining parasite species, low prevalence prevented meaningful statistical analyses. The observed parasite species richness, prevalence, and abundance for A. spinosissimus were low compared to values reported for other Acomys spp. This may be linked to the lack of anthropogenic influences in the study population as well as the small size of A. spinosissimus .

Gastrointestinal parasites and prey items from a mass stranding of false killer whales, Pseudorca crassidens, in Rio Grande do Sul, Southern Brazil.

PubMed

Andrade, A L; Pinedo, M C; Barreto, A S

2001-02-01

The gastrointestinal tract of 14 false killer whales, 6 males and 8 females, stranded in June 1995 in southern Brazil, with total standard lengths from 338 to 507 cm, were analysed for endoparasites and food items. A pregnant female had a male foetus of 77.5 cm. Parasites were found in all 14 false killer whales. The nematode Anisakis simplex (Rudolphi, 1809) was found in the stomach of 57% of the animals and the acanthocephalan Bolbosoma capitatum (Linstow, 1889) Porta, 1908 was present in the intestine of all specimens and showed densities up to 600 m-1. An unidentified cestode (Tethrabothridae) was found also in the intestines of 14% of the individuals. The high infections of B. capitatum and A. simplex were not directly related with the cause of death. In the stomachs of four females, beaks of at least eight specimens of the oceanic and epipelagic species Ommastrephes bartramii (Lesueur, 1821) were found, with mantle lengths ranging from 189.8 to 360.9 mm. The distribution of O. bartramii in the coast of Rio Grande do Sul is consistent with false killer whales feeding in continental shelf waters.

Characterization of the Complete Mitochondrial Genome Sequence of Spirometra erinaceieuropaei (Cestoda: Diphyllobothriidae) from China

PubMed Central

Liu, Guo-Hua; Li, Chun; Li, Jia-Yuan; Zhou, Dong-Hui; Xiong, Rong-Chuan; Lin, Rui-Qing; Zou, Feng-Cai; Zhu, Xing-Quan

2012-01-01

Sparganosis, caused by the plerocercoid larvae of members of the genus Spirometra, can cause significant public health problem and considerable economic losses. In the present study, the complete mitochondrial DNA (mtDNA) sequence of Spirometra erinaceieuropaei from China was determined, characterized and compared with that of S. erinaceieuropaei from Japan. The gene arrangement in the mt genome sequences of S. erinaceieuropaei from China and Japan is identical. The identity of the mt genomes was 99.1% between S. erinaceieuropaei from China and Japan, and the complete mtDNA sequence of S. erinaceieuropaei from China is slightly shorter (2 bp) than that from Japan. Phylogenetic analysis of S. erinaceieuropaei with other representative cestodes using two different computational algorithms [Bayesian inference (BI) and maximum likelihood (ML)] based on concatenated amino acid sequences of 12 protein-coding genes, revealed that S. erinaceieuropaei is closely related to Diphyllobothrium spp., supporting classification based on morphological features. The present study determined the complete mtDNA sequences of S. erinaceieuropaei from China that provides novel genetic markers for studying the population genetics and molecular epidemiology of S. erinaceieuropaei in humans and animals. PMID:22553464

[Helminth fauna Anseriformes (Aves) in the Lodz Zoological Garden].

PubMed

Zuchowska, E

1997-01-01

In the years 1959-1990 429 birds on 30 species of Anseriformes were examined post mortem at Zoo Lódź. The helminths were found in 108 birds (25.17%) of 19 species. In infected birds there were found 4 species of trematodes: one of them, Catatropis verrucosa is in Poland new for Cygnus olor; 9 species of cestodes--7 of them are in Poland new for examined hosts; namely: Drepanidotaenia lanceolata for Dendrocygna viduata, Cygnus atratus, Branta bernicla, and Anas platyrhynchos; Microsomacanthus paracompressus for Cygnus olor; Dicranotaenia coronula for Chloephaga picta and Cairina moschata; Cloacotaenia megalops for Branta bernicla, Tschertkovilepis setigera for Cygnus olor, Anser indicus, Branta bernicla and Anas platyrhynchos; Fimbriaria fasciolaris for Cygnus olor and Chloephaga picta; Sobolevicanthus gracilis for Cygnus atratus, Chloephaga picta and Tadorna tadorna; 13 species of nematodes--7 of them are in Poland new for examined hosts, namely: Cyathostoma variegatum for Cygnus atratus, Anser indicus and Anser caerulescens; Syngamus trachea for Anser indicus; Echinuria uncinata for Anser indicus; Ganguleterakis dispar for Cgynus melanocoryphus, Cgynus olor and Anser caerulescens; Pterothominx caudinflata for Anser indicus; Amidostomum ansersis for Cygnus olor and Branta bernicla; Capillaria anatis for Anas acuta. No acanthocephalans were observed.

Echinococcus and Taenia spp. from captive mammals in the United Kingdom.

PubMed

Boufana, B; Stidworthy, M F; Bell, S; Chantrey, J; Masters, N; Unwin, S; Wood, R; Lawrence, R P; Potter, A; McGarry, J; Redrobe, S; Killick, R; Foster, A P; Mitchell, S; Greenwood, A G; Sako, Y; Nakao, M; Ito, A; Wyatt, K; Lord, B; Craig, P S

2012-11-23

Taeniid tapeworms which include Echinococcus and Taenia spp. are obligatory parasites of mammals with pathogenicity usually related to the larval stages of the life cycle. Two species (or genotypes) of Echinococcus, E. granulosus sensu stricto and E. equinus, as well as several Taenia spp. are endemic in the UK. Here we report on the occurrence of larval cystic stages of Echinococcus and Taenia spp. in captive mammals in the UK. Using molecular techniques we have identified E. granulosus (G1 genotype) in a guenon monkey and a Philippine spotted deer; E. equinus in a zebra and a lemur; E. ortleppi in a Philippine spotted deer; E. multilocularis in a macaque monkey and Taenia polyacantha in jumping rats. To the best of our knowledge this is the first report of E. multilocularis in a captive primate translocated to the UK. As far as we know these are the first reports of E. equinus in a primate (lemur) and in a zebra; as well as E. granulosus (G1 genotype) and E. ortleppi in a cervid translocated to the UK. These infections and implications of the potential establishment of exotic species of cestodes are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

Molecular Approaches to Taenia asiatica

PubMed Central

Jeon, Hyeong-Kyu

2013-01-01

Taenia solium, T. saginata, and T. asiatica are taeniid tapeworms that cause taeniasis in humans and cysticercosis in intermediate host animals. Taeniases remain an important public health concerns in the world. Molecular diagnostic methods using PCR assays have been developed for rapid and accurate detection of human infecting taeniid tapeworms, including the use of sequence-specific DNA probes, PCR-RFLP, and multiplex PCR. More recently, DNA diagnosis using PCR based on histopathological specimens such as 10% formalin-fixed paraffin-embedded and stained sections mounted on slides has been applied to cestode infections. The mitochondrial gene sequence is believed to be a very useful molecular marker for not only studying evolutionary relationships among distantly related taxa, but also for investigating the phylo-biogeography of closely related species. The complete sequence of the human Taenia tapeworms mitochondrial genomes were determined, and its organization and structure were compared to other human-tropic Taenia tapeworms for which complete mitochondrial sequence data were available. The multiplex PCR assay with the Ta4978F, Ts5058F, Tso7421F, and Rev7915 primers will be useful for differential diagnosis, molecular characterization, and epidemiological surveys of human Taenia tapeworms. PMID:23467738

Activity of the nematophagous fungi Pochonia chlamydosporia, Duddingtonia flagrans and Monacrosporium thaumasium on egg capsules of Dipylidium caninum.

PubMed

Araujo, Juliana Milani; de Araújo, Jackson Victor; Braga, Fabio Ribeiro; Carvalho, Rogério Oliva; Ferreira, Sebastião Rodrigo

2009-12-03

Nematophagous fungi are potential biological control agents of helminths. The in vitro ovicidal effect of four isolates of the nematophagous fungi Pochonia chlamydosporia (VC1 and VC4), Duddingtonia flagrans (AC001) and Monacrosporium thaumasium (NF34) was evaluated on egg capsules of Dipylidium caninum, a cestode parasite of dogs, cats and humans. One thousand egg capsules of D. caninum were plated on 2% water-agar with the grown isolates and control without fungus. The ovicidal activity of these fungi was evaluated 5, 10 and 15 days after incubation. Only P. chlamydosporia showed ovicidal activity (p<0.05) on D. caninum egg capsules, of 19.6% (VC1) and 20% (VC4) on the 5th day; 44.2% (VC1) and 31.5% (VC4) on the 10th day; and 49.2% (VC1) and 41.9% (VC4) on the 15th day. D. flagrans and M. thaumasium caused no morphological damage to egg capsules. The results demonstrated that P. chlamydosporia was in vitro effective against capsules and eggs of D. caninum, and can be considered as a potential biological control agent for this helminth.

Community-based surveillance of zoonotic parasites in a 'One Health' world: A systematic review.

PubMed

Schurer, J M; Mosites, E; Li, C; Meschke, S; Rabinowitz, P

2016-12-01

The One Health (OH) concept provides an integrated framework for observing and improving health issues involving human, animal, and environmental factors, and has been applied in particular to zoonotic disease problems. We conducted a systematic review of English and Chinese language peer-reviewed and grey literature databases to identify zoonotic endoparasite research utilizing an OH approach in community-based settings. Our review identified 32 articles where specimens collected simultaneously from all three OH domains (people, animals, and the environment) were assessed for endoparasite infection or exposure. Study sites spanned 23 countries, and research teams brought together an average of seven authors from two countries. Surveillance of blood-borne and gastrointestinal protozoa were most frequently reported (19 of 32; 59%), followed by trematodes, nematodes, and cestodes. Laboratory techniques varied greatly between studies, and only 16 identified parasites using Polymerase Chain Reaction (PCR) in all three OH domains. Our review identified important gaps in parasitology research operating under an OH framework. We recommend that investigators working in the realm of zoonotic disease strive to evaluate all three OH domains by integrating modern molecular tools as well as techniques provided by economists and social scientists.

Intestinal Parasites and Anthelmintic Treatments in a Laboratory Colony of Wild-caught African Pouched Rats (Cricetomys ansorgei)

PubMed Central

Cullin, Cassandra O; Sellers, Matthew S; Rogers, Erin R; Scott, Kathleen E; Lee, Danielle N; Ophir, Alexander G; Jackson, Todd A

2017-01-01

African giant pouched rats (Cricetomys spp.) are large rodents native to subSaharan Africa. Wild-caught pouched rats identified as Cricetomys ansorgei (n = 49) were imported from Tanzania. A survey of gastrointestinal parasitism by fecal flotation revealed the presence of multiple parasites, including Nippostrongylus spp., Heterakis spp., Trichuris spp., Hymenolepis spp., Raillietina spp., and Eimeria spp. Oral self-administered fenbendazole (150 ppm), topical moxidectin (2 mg/kg), pyrantel pamoate (15 mg/kg), piperazine (100 mg/kg daily), and injectable ivermectin (0.25 mg/kg) were used to determine effective treatment options for the gastrointestinal parasites present in the colony. Pyrantel pamoate in a treat vehicle and piperazine in water bottles were easily administered and significantly reduced the numbers of animals shedding Nippostrongylus spp. and Heterakis spp. during the study. Moxidectin and ivermectin were clinically ineffective at reducing fecal egg shedding. Fenbendazole was most effective at clearing infection with Trichuris spp. Although 10 mg/kg praziquantel was ineffective, a single dose of 30 mg/kg praziquantel significantly reduced the number of African pouched rats that shed cestode embryos. A combination treatment may be necessary to successfully treat all parasites present in any given animal. PMID:28935004

Endoparasites of the Eastern Rock Sengi (Elephantulus myurus) from South Africa.

PubMed

Lutermann, Heike; Medger, Katarina; Junker, Kerstin

2015-12-01

The endoparasite fauna of the eastern rock sengi ( Elephantulus myurus Thomas and Schwann) was studied for the first time for any sengi species from September 2007 until August 2008 in the Limpopo Province of South Africa. From the 121 sengis examined, we recovered 11 endoparasite taxa, including 9 nematodes, 1 cestode family (Hymenolepididae), and 1 pentastomid species (Armillifer armillatus (Wyman, 1834)). The overall endoparasite prevalence was high, at 100%, and largely attributable to the nematode Maupasina weissi Seurat, 1913 , with only a single individual being parasite free. Despite the high diversity, species richness was low (1.58 ± 0.06) and only M. weissi and spiruroid larvae occurred at a prevalence exceeding 8%. The abundance of M. weissi varied significantly between seasons and was lowest in summer and autumn. In contrast, the abundance of spiruroid larvae remained relatively constant across seasons in males, but was significantly higher in spring and summer compared to winter in females. These patterns may be generated by an accumulation of M. weissi with age as well as sex-specific seasonal shifts in diet. An updated list on the hosts and geographic range of parasites of sengis is provided.

Filtering out parasites: sand crabs (Lepidopa benedicti) are infected by more parasites than sympatric mole crabs (Emerita benedicti)

PubMed Central

2017-01-01

Two digging decapod crustaceans, the sand crab species Lepidopa benedicti and the mole crab species Emerita benedicti, both live in the swash zone of fine sand beaches. They were examined for two parasites that infect decapod crustaceans in the region, an unidentified nematode previously shown to infect L. benedicti, and cestode tapeworm larvae, Polypocephalus sp., previously shown to infect shrimp (Litopenaeus setiferus). Lepidopa benedicti were almost always infected with both parasite species, while E. benedicti were rarely infected with either parasite species. This difference in infection pattern suggests that tapeworms are ingested during sediment feeding in L. benedicti, which E. benedicti avoid by filter feeding. Larger L. benedicti had more Polypocephalus sp. larvae. The thoracic ganglia, which make up the largest proportion of neural tissue, contained the largest numbers of Polypocephalus sp. larvae. Intensity of Polypocephalus sp. infection was not correlated with how long L. benedicti remained above sand in behavioural tests, suggesting that Polypocephalus sp. do not manipulate the sand crabs in a way that facilitates trophic transmission of the parasite. Litopenaeus setiferus may be a primary host for Polypocephalus sp., and L. benedict may be a secondary, auxiliary host. PMID:28951818

First study of vitellogenesis of the broad fish tapeworm Diphyllobothrium latum (Cestoda, Diphyllobothriidea), a human parasite with extreme fecundity.

PubMed

Yoneva, Aneta; Kuchta, Roman; Scholz, Tomáš

2014-12-01

In the present study, the process of vitellogenesis of one of the most prolific organisms, the broad tapeworm, Diphyllobothrium latum, the causative agent of human diphyllobothriosis, was studied for the first time using transmission electron microscopy. Cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for detection of glycogen was applied. Starting from the periphery toward the center of the vitelline follicle four stages of vitellocytes are differentiated: immature vitellocytes, early maturing vitellocytes, advanced maturing and mature vitellocytes. Differentiation into mature vitellocytes involves the formation of shell globule clusters containing shell globules, large amount of saturated lipid droplets and glycogen. A peculiar ultrastructural feature of D. latum vitellogenesis is the presence of lamellar bodies in the cytoplasm of mature vitellocytes. This feature is similar to that present in the closely related caryophyllideans and spathebothriideans. Despite the great similarity observed in the embryonic development of diphylobothriideans, caryophyllideans and spathebothriideans, and the fact that their vitellocytes share a feature not reported from other cestode groups, there are substantial differences in the morphology of vitelline clusters, types, amount and localization of their nutritive reserves. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Redescription and molecular characterization of Anoplocephala manubriata, Railliet et al., 1914 (Cestoda: Anoplocephalidae) from a Sri Lankan wild elephant (Elephas maximus).

PubMed

Perera, K U E; Wickramasinghe, Susiji; Perera, B V P; Bandara, K B A T; Rajapakse, R P V J

2017-06-01

The present work provides a detailed morphological and molecular description of Anoplocephala manubriata in elephants. Adult worms were recovered during an autopsy of a wild elephant in Elephant Transit Home, Udawalawe, Sri Lanka. Necropsy findings revealed a severe cestode infection in the small intestine. These tapeworms were tightly attached to the intestinal mucosae, resulted in hyperemic thickened intestinal mucosae, variable size irregular well-demarcated multifocal ulcerative regions sometimes covered with necrotic membranes and variable size, diffuse, well-demarcated raised nodular masses were evident in the small intestine. The article provides an account of the biology of A. manubriata and a comparative analysis of the morphology and morphometrics of Anoplocephala species that occur in different hosts. Phylogenetic analysis of the second internal transcribed spacer region (ITS-2), a portion of the 28S region and cytochrome oxidase subunit 1 (COX1) genes revealed that A. manubriata is closely associated with Anoplocephala species in horse in comparison to other Anoplocephalines. This study will enhance the current knowledge in taxonomy of elephant tapeworms and contribute to future phylogenetic studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Prevalence and diversity of gastrointestinal helminths in free-ranging Asian house shrew (Suncus murinus) in Bangladesh.

PubMed

Rahman, Mizanur; Islam, Shariful; Masuduzzaman, Md; Alam, Mahabub; Chawdhury, Mohammad Nizam Uddin; Ferdous, Jinnat; Islam, Md Nurul; Hassan, Mohammad Mahmudul; Hossain, Mohammad Alamgir; Islam, Ariful

2018-04-01

Asian house shrew ( Suncus murinus ), a widely distributed small mammal in the South Asian region, can carry helminths of zoonotic importance. The aim of the study was to know the prevalence and diversity of gastrointestinal (GI) helminths in free-ranging Asian house shrew ( S. murinus ) in Bangladesh. A total of 86 Asian house shrews were captured from forest areas and other habitats of Bangladesh in 2015. Gross examination of the whole GI tract was performed for gross helminth detection, and coproscopy was done for identification of specific eggs or larvae. The overall prevalence of GI helminth was 77.9% (67/86), with six species including nematodes (3), cestodes (2), and trematodes (1). Of the detected helminths, the dominant parasitic group was from the genus Hymenolepis spp.(59%), followed by Strongyloides spp.(17%), Capillaria spp. (10%), Physaloptera spp. (3%), and Echinostoma spp.(3%). The finding shows that the presence of potential zoonotic parasites (Hymenolepis spp. and Capillaria spp.) in Asian house shrew is ubiquitous in all types of habitat (forest land, cropland and dwelling) in Bangladesh. Therefore, further investigation is crucial to examine their role in the transmission of human helminthiasis.

Tropical veterinary parasites at Harvard University's Museum of Comparative Zoology.

PubMed

Conn, David Bruce

2008-12-01

Tropical veterinary parasites have been maintained by the Museum of Comparative Zoology (MCZ) at Harvard University since the mid 1800s. Most of these are maintained by the Department of Invertebrate Zoology, but many vectors and intermediate hosts are maintained by the Departments of Entomology and Malacology. The largest collections are of avian and mammalian ticks (Acarina) that are important as both parasites and vectors. Nematodes are second in numbers, followed by cestodes, trematodes, and several minor helminth groups, crustacean parasites of fish, and protozoan parasites of various hosts. The MCZ directed or participated in several major expeditions to tropical areas around the globe in the early 1900s. Many of these expeditions focused on human parasites, but hundreds of veterinary and zoonotic parasites were also collected from these and numerous, smaller, tropical expeditions. Host sources include companion animals, livestock, laboratory species, domestic fowl, reptiles, amphibians, exotics/zoo animals, commercially important fishes, and other wildlife. Specimens are curated, either fixed whole in vials or mounted on slides as whole mounts or histopathological sections. The primary emphasis of MCZ's current work with tropical veterinary parasites is on voucher specimens from epidemiological, experimental, and clinical research.

The immunological response of the rat to infection with Taenia taeniaeformis. V. Sequence of appearance of protective immunoglobulins and the mechanism of action of 7Sgamma2a antibodies.

PubMed Central

Musoke, A J; Williams, J F

1975-01-01

Passive transfer of immunity to Taenia taeniaeformis was achieved with serum taken 14, 21, 49 and 63 days after infection. The protective capacity of serum collected at 14 and 21 days resided in the 7Sgamma2 immunoglobulins and appeared to be partics the infection progressed the range of chromatographic fractions showing protective capacity was extended to all those containing 7Sgamma2 and 7Sgamma1 immunoglobulins. Fractions enriched for gammaM did not confer protection. Immune serum containing 7Sgamma2a antibodies was able to kill developing parasites after they had left the intestine, and the hepatic postoncospheral forms retained their susceptibility to antibody over the first 5 days of growth. After that time they rapidly became insusceptible to antibody both in vivo and in vitro. Susceptibility to antibody-mediated attack was complement dependent. This appears to be the first time that complement has been demonstrated to play a role in immunity to a helminth infection in vivo. This finding is discussed in relation to the phenomenon of cestode parasite survival in immune animals. Images FIG. 1 PMID:1201860

Intestinal parasites of the gopher tortoise (Gopherus polyphemus) from eight populations in Georgia.

PubMed

McGuire, Jessica L; Miller, Elizabeth A; Norton, Terry M; Raphael, Bonnie L; Spratt, Jeffrey S; Yabsley, Michael J

2013-12-01

The gopher tortoise (Gopherus polyphemus), one of five tortoise species endemic in the USA, was recently classified as a candidate for federal listing as a threatened species. Fecal samples collected from 117 tortoises from eight sites in Georgia were examined for endoparasites using a combination of sedimentation and flotation. Samples from an island population were examined for parasitic oocysts and ova only by flotation, protozoan cysts by trichrome-stained direct smear, and Cryptosporidium by direct immunofluorescence assay and ProSpecT rapid assay. A total of 99 tortoises (85, range 0-100%) was infected with pinworms (Alaeuris spp.), 47 (40, 0-86%) with cestodes (Oochorstica sp.), 34 (41, 0-74%) with Chapiniella spp., 2 (3, 0-33%) with Eimeria paynei, and a single tortoise each with a capillarid and ascarid (1%). On the island, Entamoeba was detected in one tortoise (2%) while Cryptosporidium oocysts were detected in eight (17%). In conclusion, at least eight species of parasites were detected including Cryptosporidium, a possible pathogen of tortoises. Interestingly, we detected spatial variation in the distribution of several parasites among populations suggesting additional work should be conducted across a gradient of tortoise densities, land use, and habitat characteristics.

Capillaria hepatica infection in black rats (Rattus rattus) on Diego Garcia, British Indian Ocean Territory.

PubMed

Berentsen, Are R; Vogt, Scott; Guzman, Antenor N; Vice, Daniel S; Pitt, William C; Shiels, Aaron B; Spraker, Terry R

2015-03-01

Rats (Rattus spp.) are among the most damaging invasive species worldwide. The accidental introduction of rats has caused significant detriment to native flora and fauna, crops, structures, and human livelihoods. Rats are vectors of disease and carriers of various zoonotic parasites. Capillaria hepatica (syn. Callodium hepaticum) is a parasitic nematode found primarily in rodents but is known to infect over 140 mammal species, including human beings and several species of domestic animals. In this case study, the presence of C. hepatica infection in black rats on Diego Garcia, British Indian Ocean Territory, is reported. Liver samples from 20 black rats (Rattus rattus) were collected during a concurrent population density estimation study. Histology revealed 15 (75%) of the rats sampled had a current or previous infection with C. hepatica. In addition, a larval cestode compatible in size and shape with Cysticercus fasciolaris, the larval stage of Taenia taeniaeformis of cats, was found in 3 (15%) of the rats sampled. The high prevalence of C. hepatica infection in rats on Diego Garcia has implications for human health given the high population density of rats found on the island. © 2015 The Author(s).

Secretory products of helminth parasites as immunomodulators.

PubMed

Harnett, William

2014-07-01

Parasitic helminths release molecules into their environment, which are generally referred to as excretory-secretory products or ES. ES derived from a wide range of nematodes, trematodes and cestodes have been studied during the past 30-40 years, their characterization evolving from simple biochemical procedures such as SDS-PAGE in the early days to sophisticated proteomics in the 21st century. Study has incorporated investigation of ES structure, potential as vaccines, immunodiagnostic utility, functional activities and immunomodulatory properties. Immunomodulation by ES is increasingly the area of most intensive research with a number of defined helminth products extensively analyzed with respect to the nature of their selective effects on cells of the immune system as well as the molecular mechanisms, which underlie these immunomodulatory effects. As a consequence, we are now beginning to learn the identities of the receptors that ES employ and are increasingly acquiring detailed knowledge of the signalling pathways that they interact with and subvert. Such information is contributing to the growing idea that the anti-inflammatory properties of a number of ES products makes them suitable starting points for the development of novel drugs for treating human inflammatory disease. Copyright © 2014 Elsevier B.V. All rights reserved.

Granulocytes in Helminth Infection - Who is Calling the Shots?

PubMed Central

Makepeace, BL; Martin, C; Turner, JD; Specht, S

2012-01-01

Helminths are parasitic organisms that can be broadly described as “worms” due to their elongated body plan, but which otherwise differ in shape, development, migratory routes and the predilection site of the adults and larvae. They are divided into three major groups: trematodes (flukes), which are leaf-shaped, hermaphroditic (except for blood flukes) flatworms with oral and ventral suckers; cestodes (tapeworms), which are segmented, hermaphroditic flatworms that inhabit the intestinal lumen; and nematodes (roundworms), which are dioecious, cylindrical parasites that inhabit intestinal and peripheral tissue sites. Helminths exhibit a sublime co-evolution with the host´s immune system that has enabled them to successfully colonize almost all multicellular species present in every geographical environment, including over two billion humans. In the face of this challenge, the host immune system has evolved to strike a delicate balance between attempts to neutralize the infectious assault versus limitation of damage to host tissues. Among the most important cell types during helminthic invasion are granulocytes: eosinophils, neutrophils and basophils. Depending on the specific context, these leukocytes may have pivotal roles in host protection, immunopathology, or facilitation of helminth establishment. This review provides an overview of the function of granulocytes in helminthic infections. PMID:22360486

Zoonotic helminths affecting the human eye

PubMed Central

2011-01-01

Nowaday, zoonoses are an important cause of human parasitic diseases worldwide and a major threat to the socio-economic development, mainly in developing countries. Importantly, zoonotic helminths that affect human eyes (HIE) may cause blindness with severe socio-economic consequences to human communities. These infections include nematodes, cestodes and trematodes, which may be transmitted by vectors (dirofilariasis, onchocerciasis, thelaziasis), food consumption (sparganosis, trichinellosis) and those acquired indirectly from the environment (ascariasis, echinococcosis, fascioliasis). Adult and/or larval stages of HIE may localize into human ocular tissues externally (i.e., lachrymal glands, eyelids, conjunctival sacs) or into the ocular globe (i.e., intravitreous retina, anterior and or posterior chamber) causing symptoms due to the parasitic localization in the eyes or to the immune reaction they elicit in the host. Unfortunately, data on HIE are scant and mostly limited to case reports from different countries. The biology and epidemiology of the most frequently reported HIE are discussed as well as clinical description of the diseases, diagnostic considerations and video clips on their presentation and surgical treatment. Homines amplius oculis, quam auribus credunt Seneca Ep 6,5 Men believe their eyes more than their ears PMID:21429191

Prevalence of endoparasitic infections of birds in zoo gardens in Serbia.

PubMed

Ilić, Tamara; Becskei, Zsolt; Gajić, Bojan; Özvegy, József; Stepanović, Predrag; Nenadović, Katarina; Dimitrijević, Sanda

2018-03-26

This report represents the prevalence of endoparasitic infections of birds in zoological gardens in Serbia. Coprological examination conducted during 2015 and 2016, involved samples from 318 individual birds belonging to 112 species, in three zoo gardens (Belgrade, Palić and Bor). Individual faeces samples were analysed by the flotation method in salt solution. The presence of endoparasites was established in 51.96% (Belgrade), 46.16% (Palić) and 16.66% (Bor) of the tested birds. We diagnosed coccidian oocysts, eggs of Capillaria spp, Heterakis spp, Trichostrongylus spp, Ascaridia spp, Syngamus trachea and eggs of yet unidentified trematode. There were no detection of parasites from the class of cestodes. Prevalence of infection with coccidia, depending on location, was in the ranges between 8.33% and 32.84%, capillariosis 2.77% and 29.41%, heterakiosis 2.56% and 12.74%, trichostrongylidosis 5.55% and 25.64%, askaridiosis 10.25% and 10.78%, syngamosis 2.94% and trematodes of unknown etiology 2.45%. Coinfections with two or three parasitic species were detected in Belgrade and Palić Zoo Gardens, while quadruple infection was established in birds of Belgrade Zoo Garden. Obtained results can be used in establishing programs for health protection of endangered bird species.

[Ultrastructural characteristics of the vitellaria, uterus and vagina of Amphilina foliacea Rudolphi, 1819 (Cestoda: Amphilinidea)].

PubMed

Poddubnaia, L G

2013-01-01

The ultrastructural features of the vitelline follicles, uterus and vagina of the amphilinid cestode Amphilina foliacea from the body cavity of Acipenser ruthenus of the Volga basin are described. Some new distinguishing characters are revealed, including the presence of a single type of the cellular component in the vitelline follicles with sarcoplasmic processes filling the space around and within vitellocytes. The,uterus of this species is recognized by the presence of the syncytial epithelial lining with underlying secretory perikaria and different kinds of luminal projections. The most distal part of the uterus, situated closely to the uterine pore, is characterized by nuclei occupying the syncytial uterine epithelium. Slightly further proximally, they are located basally and then transformed into sunken perikaria. The vaginal epithelium is characterized by the syncytial structure with underlying epithelial perikaria in its distal region, with intraepithelial location of the nuclei slightly further proximally and the absence of the nuclei in its proximal region (the seminal receptacle). The syncytial cytoplasm of the vagina contains numerous vesicles and possesses microvilli-like surface structures. The morphological aspects of the female reproductive system of A. foliacea are compared with those of other Cestoda and Neodermata.

Synonymous codon usage patterns in different parasitic platyhelminth mitochondrial genomes.

PubMed

Chen, L; Yang, D Y; Liu, T F; Nong, X; Huang, X; Xie, Y; Fu, Y; Zheng, W P; Zhang, R H; Wu, X H; Gu, X B; Wang, S X; Peng, X R; Yang, G Y

2013-02-27

We analyzed synonymous codon usage patterns of the mitochondrial genomes of 43 parasitic platyhelminth species. The relative synonymous codon usage, the effective number of codons (NC) and the frequency of G+C at the third synonymously variable coding position were calculated. Correspondence analysis was used to determine the major variation trends shaping the codon usage patterns. Among the mitochondrial genomes of 19 trematode species, the GC content of third codon positions varied from 0.151 to 0.592, with a mean of 0.295 ± 0.116. In cestodes, the mean GC content of third codon positions was 0.254 ± 0.044. A comparison of the nucleotide composition at 4-fold synonymous sites revealed that, on average, there was a greater abundance of codons ending on U (51.9%) or A (22.7%) than on C (6.3%) or G (19.14%). Twenty-two codons, including UUU, UUA and UUG, were frequently used. In the NC-plot, most of points were distributed well below or around the expected NC curve. In addition to compositional constraints, the degree of hydrophobicity and the aromatic amino acids also influenced codon usage in the mitochondrial genomes of these 43 parasitic platyhelminth species.

Host specificity and the probability of discovering species of helminth parasites.

PubMed

Poulin, R; Mouillot, D

2005-06-01

Different animal species have different probabilities of being discovered and described by scientists, and these probabilities are determined to a large extent by the biological characteristics of these species. For instance, species with broader geographical ranges are more likely to be encountered by collectors than species with restricted distributions; indeed, the size of the geographical range is often the best predictor of a species' date of description. For parasitic organisms, host specificity may be similarly linked to the probability of a species being found. Here, using data on 170 helminth species parasitic in freshwater fishes, we show that host specificity is associated with the year in which the helminths were described. Helminths that exploit more host species, and to a lesser degree those that exploit a broader taxonomic range of host species, tend to be discovered earlier than the more host-specific helminths. This pattern was observed across all helminth species, as well as within the different helminth taxa (trematodes, cestodes, nematodes and acanthocephalans). Our results demonstrate that the parasite species known at any given point in time are not a random subset of existing species, but rather a biased subset with respect to the parasites' biological properties.

Gastrointestinal Helminths in Slaughtered Cattle in Ibadan, South-Western Nigeria.

PubMed

Adedipe, Olubukola Deborah; Uwalaka, Emmanuel Chibuike; Akinseye, Victor Oluwatoyin; Adediran, Oyeduntan Adejoju; Cadmus, Simeon Idowu Babalola

2014-01-01

As part of an ongoing project to investigate the epidemiology of gastrointestinal helminths of cattle in Nigeria, we carried out a systematic random sampling of cattle slaughtered in a major abattoir in Ibadan, south-western Nigeria. Using sedimentation and floatation methods, we analyzed fecal samples from 397 animals between March and May 2013. Overall, 163 (41.6%) of the animals had at least one gastrointestinal helminth egg, comprising a total of eight helminths from different genera (i.e., four nematodes, three trematodes, and one cestode), with nematode infection being the highest (71.54%). In addition, eggs of four helminths of zoonotic importance were also obtained. Among the cattle examined, the Bunaji breed was the most infected (46%; 69/150). Furthermore, female animals (OR = 1.1; 95% CI: 0.60-1.84) and animals with moderate body condition (OR = 1.2; 95% CI: 0.80-1.79) are more likely to be positive to helminth infection. Our findings reveal that there were helminth infections of both zoonotic and socioeconomic importance among the cattle screened. Considering the impact of the infections on animal production and public health, we advocate that effective prophylactic measures be adopted as a first step to curtail helminth infections of cattle in Nigeria.

Helminth community structure of Tropidurus torquatus (Squamata: Tropiduridae) in a rocky outcrop area of Minas Gerais state, southeastern Brazil.

PubMed

Pereira, Felipe B; Sousa, Bernadete M; Lima, Sueli de Souza

2012-02-01

The helminth community of Tropidurus torquatus (Squamata: Tropiduridae) from a rocky outcrop area located in the state of Minas Gerais, southeastern Brazil, was studied. Ninety-two of the 110 individuals examined (83.6%) harbored helminths. Five species were found, including 3 nematodes ( Physaloptera lutzi , Parapharyngodon bainae , and Oswaldofilaria chabaudi ), 1 unidentified cestode species, and 1 acanthocephalan cystacanth also not identified. Only the nematode species had sufficient data to perform ecological analysis, with P. lutzi exhibiting the highest prevalence (67.3%). Prevalence between male and female hosts differed only for Oswaldofilaria chabaudi , with males exhibiting the highest values. The intensities of infection by P. lutzi and O. chabaudi were different among male and female hosts, with males also exhibiting the highest values. The host body size was positively related to intensity of infection for all nematode species. Local seasonality had some influence on the helminth community structure. Host diet, sexual dimorphism, and behavior (territorialism, forage strategy) represented important factors for the structure of this parasite community. In general, the helminth community was species poor, depauperate, and non-interactive, representing a typical structure observed in lizard hosts.

An experimental conflict of interest between parasites reveals the mechanism of host manipulation

PubMed Central

Milinski, Manfred

2016-01-01

Parasites can increase their host’s predation susceptibility. It is a long-standing puzzle, whether this is caused by host manipulation, an evolved strategy of the parasite, or by side effects due to, for example, the parasite consuming energy from its host thereby changing the host’s trade-off between avoiding predation and foraging toward foraging. Here, we use sequential infection of three-spined sticklebacks with the cestode Schistocephalus solidus so that parasites have a conflict of interest over the direction of host manipulation. With true manipulation, the not yet infective parasite should reduce rather than enhance risk taking because predation would be fatal for its fitness; if host behavior is changed by a side effect, the 2 parasites would add their increase of predation risk because both drain energy. Our results support the latter hypothesis. In an additional experiment, we tested both infected and uninfected fish either starved or satiated. True host manipulation should act independently of the fish’s hunger status and continue when energy drain is balanced through satiation. Starvation and satiation affect the risk averseness of infected sticklebacks similarly to that of uninfected starved and satiated ones. Increased energy drain rather than active host manipulation dominates behavioral changes of S. solidus-infected sticklebacks. PMID:27004014

An experimental conflict of interest between parasites reveals the mechanism of host manipulation.

PubMed

Hafer, Nina; Milinski, Manfred

2016-01-01

Parasites can increase their host's predation susceptibility. It is a long-standing puzzle, whether this is caused by host manipulation, an evolved strategy of the parasite, or by side effects due to, for example, the parasite consuming energy from its host thereby changing the host's trade-off between avoiding predation and foraging toward foraging. Here, we use sequential infection of three-spined sticklebacks with the cestode Schistocephalus solidus so that parasites have a conflict of interest over the direction of host manipulation. With true manipulation, the not yet infective parasite should reduce rather than enhance risk taking because predation would be fatal for its fitness; if host behavior is changed by a side effect, the 2 parasites would add their increase of predation risk because both drain energy. Our results support the latter hypothesis. In an additional experiment, we tested both infected and uninfected fish either starved or satiated. True host manipulation should act independently of the fish's hunger status and continue when energy drain is balanced through satiation. Starvation and satiation affect the risk averseness of infected sticklebacks similarly to that of uninfected starved and satiated ones. Increased energy drain rather than active host manipulation dominates behavioral changes of S. solidus -infected sticklebacks.

Update on the distribution of the invasive Asian fish tapeworm, Bothriocephalus acheilognathi, in the U.S. and Canada

USGS Publications Warehouse

Choudhury, A.; Charipar, E.; Nelson, P.; Hodgson, J.R.; Bonar, S.; Cole, Rebecca A.

2006-01-01

The documented range of the invasive and potentially pathogenic Asian fish tapeworm, Bothriocephalus acheilognathi Yamaguti, 1934 in the United States and Canada is updated based on examination of museum depositions and original field collections. Gravid specimens of B. acheilognathi were collected from the fathead minnow Pimephales promelas Rafinesque in Peter Lake, at the University of Notre Dame Environmental Research Center (UNDERC) Land o' Lakes, Wisconsin. A single immature specimen of the parasite was collected from a white bass, Morone chrysops (Rafinesque) in Lake Winnipeg, Manitoba, Canada. This is the first record of B. acheilognathi in Canada and extends its northern range in the interior of the continent by more than 600 miles over the last documented record. The previous record of B. acheilognathi in Canada, from the northern pikeminnow, Ptychocheilus oregonensis in British Columbia, is a misidentification of Eubothrium tulipai. Examination of selected records of intestinal cestodes from native cyprinids, in the Harold W. Manter Laboratory of Parasitology (HWML, n = 9) collection and in the United States National Parasite Collection (USNPC, n = 8), provided evidence of the parasite in Nebraska and possibly in the upper Colorado River basin. Introductions into Wisconsin-Michigan were due to the stocking of golden shiners, whereas the source of the introduction in Manitoba remains unknown.

A new species of Acanthobothrium (Eucestoda: Onchobothriidae) in Aetobatus cf. narinari (Myliobatidae) from Campeche, México.

PubMed

Rodríguez-Ibarra, Erick; Pulido-Flores, Griselda; Violante-González, Juan; Monks, Scott

2018-01-01

The helminthological examination of nine individuals of Aetobatus cf. narinari (spotted eagle ray; raya pinta; arraia pintada) revealed the presence of an undescribed species of cestode of the genus Acanthobothrium. The stingrays were collected from four locations in México: Laguna Términos, south of Isla del Carmen and the marine waters north of Isla del Carmen and Champotón, in the State of Campeche, and Isla Holbox, State of Quintana Roo. The new species, nominated Acanthobothrium marquesi, is a category 3 species (i.e, the strobila is long, has more than 50 proglottids, the numerous testicles greater than 80, and has asymmetrically-lobed ovaries); at the present, the only category 3 species that has been reported in the Western Atlantic Ocean is Acanthobothrium tortum. Acanthobothrium marquesi n. sp. can be distinguished from A. tortum by length (26.1 cm vs. 10.6 cm), greater number of proglottids (1,549 vs. 656), a larger scolex (707 µm long by 872 µm wide vs. 699 µm long by 665 µm wide), larger bothridia (626 µm long by 274 µm wide vs. 563 µm long by 238 µm wide). This is the first report of a species of Acanthobothrium from the Mexican coast of the Gulf México.

Infection status with helminthes in feral cats purchased from a market in Busan, Republic of Korea.

PubMed

Sohn, Woon Mok; Chai, Jong Yil

2005-09-01

The present study was performed to investigate the infection status with helminth in a group of feral cats in Korea. More than 29 helminth species including adults or eggs were detected in visceral and fecal samples of the examined cats. Among these were a host of nematodes, including toxocarids, Ancylostoma sp. and the larva of Anisakis simplex; trematodes, including Clonorchis sinensis, Paragonimus westermani, Eurytrema pancreaticum, Pharyngostomum cordatum, Metagonimus spp., Heterophyes nocens, Pygidiopsis summa, Heterophyopsis continua, Stictodora fuscata, Stictodora lari, Acanthotrema felis, Stellantchasmus falcatus, Centrocestus armatus, Procerovum varium, Cryptocotyle sp., Echinostoma revolutum, Echinostoma hortense, Echinochasmus japonicus, Stephanoprora sp., Plagiorchis muris, Neodiplostomum sp. and diplostomulum. We also detected a variety of cestodes, including Spirometra erinacei, Taenia taeniaeformis and unidentified species of tapeworm. We also found examples of the acanthocephalan, Bolbosoma sp. In our assessment of the stools, we detected at least 12 species of helminth eggs. These findings confirmed that feral cats in Korea are infected with a variety of helminth parasite species. Furthermore, among the helminths detected, E. pancreaticum, S. fuscata, S. lari, A. felis, S. falcatus, C. armatus, P. varium, Cryptocotyle sp., E. revolutum, E. japonicus, Stephanoprora sp., P. muris, Neodiplostomum sp. and Bolbosoma sp. represent helminth fauna which have not been reported previously in feral cats in the Republic of Korea.

Infection status with helminthes in feral cats purchased from a market in Busan, Republic of Korea

PubMed Central

Chai, Jong-Yil

2005-01-01

The present study was performed to investigate the infection status with helminth in a group of feral cats in Korea. More than 29 helminth species including adults or eggs were detected in visceral and fecal samples of the examined cats. Among these were a host of nematodes, including toxocarids, Ancylostoma sp. and the larva of Anisakis simplex; trematodes, including Clonorchis sinensis, Paragonimus westermani, Eurytrema pancreaticum, Pharyngostomum cordatum, Metagonimus spp., Heterophyes nocens, Pygidiopsis summa, Heterophyopsis continua, Stictodora fuscata, Stictodora lari, Acanthotrema felis, Stellantchasmus falcatus, Centrocestus armatus, Procerovum varium, Cryptocotyle sp., Echinostoma revolutum, Echinostoma hortense, Echinochasmus japonicus, Stephanoprora sp., Plagiorchis muris, Neodiplostomum sp. and diplostomulum. We also detected a variety of cestodes, including Spirometra erinacei, Taenia taeniaeformis and unidentified species of tapeworm. We also found examples of the acanthocephalan, Bolbosoma sp. In our assessment of the stools, we detected at least 12 species of helminth eggs. These findings confirmed that feral cats in Korea are infected with a variety of helminth parasite species. Furthermore, among the helminths detected, E. pancreaticum, S. fuscata, S. lari, A. felis, S. falcatus, C. armatus, P. varium, Cryptocotyle sp., E. revolutum, E. japonicus, Stephanoprora sp., P. muris, Neodiplostomum sp. and Bolbosoma sp. represent helminth fauna which have not been reported previously in feral cats in the Republic of Korea. PMID:16192750

Parasite communities of the neotropical cormorant Phalacrocorax brasilianus (Gmelin) (Aves, Phalacrocoracidae) from two coastal lagoons in Guerrero state, Mexico.

PubMed

Violante-González, Juan; Monks, Scott; Gil-Guerrero, Salvador; Rojas-Herrera, Agustín; Flores-Garza, Rafael; Larumbe-Morán, Edvino

2011-11-01

The parasite community structure of the neotropical cormorant, Phalacrocorax brasilianus, from two lagoons (Coyuca and Tres Palos) from Guerrero state, México, was examined. Fourteen species of adult helminths (6,391 individuals) from 48 cormorants were identified: 9 digeneans, 1 acanthocephalan, 1 cestode, and 3 nematodes. A total of 11 species were collected in Coyuca Lagoon and 12 in Tres Palos Lagoon. Nine species co-occurred in cormorants of both lagoons but, with the exception of Contracaecum multipapillatum and Drepanocephalus olivaceus, species were not equally common in both lagoons. The prevalence values of six species of helminth and the mean abundance of four species varied significantly between lagoons, and C. multipapillatum was numerically dominant in both lagoons. The qualitative similarity between the two communities at the component level was 64%. All cormorants examined were infected, and parasite species richness was 3-5 in Coyuca and 4-9 in Tres Palos lagoon. The results indicate that both communities presented a similar structure at the component level, probably because the cormorants of both lagoons feed on the same species of fish and thus acquire almost the same species of parasites. Differences observed at the infracommunity level were attributed to variations in the degree of dominance of the particular species.

Endoparasites of rodents from the Chittagong Hill Tracts in Southeastern Bangladesh.

PubMed

Fuehrer, Hans-Peter; Baumann, Timo A; Riedl, Julia; Treiber, Moritz; Igel, Petra; Swoboda, Paul; Joachim, Anja; Noedl, Harald

2012-11-01

Rodents are a key mammalian group highly successful in adapting to a variety of environments throughout the world and play an important role in many zoonotic cycles. Within this project, the gastrointestinal and extraintestinal parasite fauna of 76 rodents (Muroidea and Sciuridae) was determined in the District of Bandarban (Chittagong Hill Tracts) in Southeastern Bangladesh. Gastrointestinal and extraintestinal parasites were examined with macro- and microscopical tools (e.g. Ziehl-Neelsen Staining) at a field site in Bandarban. A wide variety of parasites were found in rodent hosts, including protozoa-Giardia sp. (n = 8), Cryptosporidium sp. (n = 1), Entamoeba sp. (n = 8), Trichomonadida (n = 4), Isospora sp. (n = 1), trematodes (Echinostoma sp.; n = 3), cestodes-Hymenolepis nana (n = 1), Hymenolepis diminuta (n = 3), Hymenolepis sp. (n = 2), Taenia taeniaeformis-Larven (n = 4), Catenotaenia sp. (n = 1), Taenia sp. (n = 1), nematodes-Heterakis spumosa (n = 4), Heterakis sp. (n = 1), Aspiculuris tetraptera (n = 2), Capillaria hepatica (n = 2), Capillaria sp. (n = 3), Syphacia sp. (n = 2), Strongyloides sp. (n = 10), Trichostrongylus sp. (n = 2) and Trichuris sp. (n = 1)-and acanthocephalans (Moniliformis moniliformis; n = 2). Several of the examined parasites are of zoonotic importance via direct or indirect transmission (e.g. C. hepatica) and may affect humans.

Rangelia vitalii in a free-ranging maned wolf (Chrysocyon brachyurus) and co-infections.

PubMed

Silveira, Julia Angélica Gonçalves; D'Elia, Mirella Lauria; de Oliveira Avelar, Isabela; de Almeida, Lara Ribeiro; Dos Santos, Hudson Andrade; de Magalhães Soares, Danielle Ferreira; Ribeiro, Múcio Flávio Barbosa; Dos Santos Lima, Walter; Ecco, Roselene

2016-12-01

An adult free-ranged female maned wolf was rescued from a periurban area subject to anthropogenic disturbances in the Minas Gerais, Brazil. The animal presented poor body condition and anemia. The clinical condition rapidly deteriorated culminating in dead and a necropsy was performed. The main gross lesions were marked anemia and blood content in the intestines accompanied by many types of parasites. The protozoa Rangelia vitalii was identified by histopathological analysis predominantly within the cytoplasm of endothelial cells of capillaries of the small intestine. The lymph nodes, spleen, bone marrow, dermis, lungs and kidney had similar protozoal forms but with mild or moderate intensity. Rangelia vitalii was confirmed by molecular assays. Hepatozoon sp., Leishmania sp., and Entamoeba spp., apparently not related to the clinical signs were also detected. The myriad parasites found in the intestines included nematodes ( Ancylostoma caninum , A . braziliensis ,, Molineus sp., Pterygodermatites sp., and Trichuris sp.), cestodes ( Spirometra sp.) and (acanthocephalans. To our knowledge, R . vitalii was identified in C . brachyurus for the first time. These findings emphasize the fragility of Brazilian ecosystems, especially in disturbed areas, reinforcing the necessity of efforts to preserve these areas and wild carnivores, some of which are threatened with extinction, such as the maned wolf.

Moxidectin: a review of chemistry, pharmacokinetics and use in horses

PubMed Central

Cobb, Rami; Boeckh, Albert

2009-01-01

This article reviews the current knowledge of the use of moxidectin (MOX) in horses, including its mode of action, pharmacokinetic and pharmacodynamic properties, efficacy, safety and resistance profile. Moxidectin is a second generation macrocyclic lactone (ML) with potent endectocide activity. It is used for parasite control in horses in an oral gel formulation. The principal mode of action of MOX and of other MLs is binding to gamma-aminobutyric (GABA) and glutamate-gated chloride channels. Moxidectin is different from other MLs in that it is a poor substrate for P-glycoproteins (P-gps) and therefore less susceptible to elimination from parasite cells through this mechanism. Due to its unique physicochemical and pharmacokinetic characteristics, MOX provides broad distribution into tissues, long half-life, significant residual antiparasitic activity, and high efficacy against encysted cyathostomin larvae. These characteristics allow for high efficacy and longer treatment interval against all important nematodes, when compared to other equine anthelmintics. A combination of MOX with praziquantel provides expanded spectrum of activity by adding activity against cestodes. Appropriate use of MOX allows for the development of strategic anthelmintic programmes that are different from those with conventional anthelmintics. Fewer treatments are required over a period of time, and therefore impose less frequent selection pressure for resistance. PMID:19778466

Update on the Human Broad Tapeworm (Genus Diphyllobothrium), Including Clinical Relevance

PubMed Central

Scholz, Tomáš; Garcia, Hector H.; Kuchta, Roman; Wicht, Barbara

2009-01-01

Summary: Tapeworms (Cestoda) continue to be an important cause of morbidity in humans worldwide. Diphyllobothriosis, a human disease caused by tapeworms of the genus Diphyllobothrium, is the most important fish-borne zoonosis caused by a cestode parasite. Up to 20 million humans are estimated to be infected worldwide. Besides humans, definitive hosts of Diphyllobothrium include piscivorous birds and mammals, which represent a significant zoonotic reservoir. The second intermediate hosts include both freshwater and marine fish, especially anadromous species such as salmonids. The zoonosis occurs most commonly in countries where the consumption of raw or marinated fish is a frequent practice. Due to the increasing popularity of dishes utilizing uncooked fish, numerous cases of human infections have appeared recently, even in the most developed countries. As many as 14 valid species of Diphyllobothrium can cause human diphyllobothriosis, with D. latum and D. nihonkaiense being the most important pathogens. In this paper, all taxa from humans reported are reviewed, with brief information on their life history and their current distribution. Data on diagnostics, epidemiology, clinical relevance, and control of the disease are also summarized. The importance of reliable identification of human-infecting species with molecular tools (sequences of mitochondrial genes) as well as the necessity of epidemiological studies aimed at determining the sources of infections are pointed out. PMID:19136438

Nataliella marcelli n. g., n. sp. (Cestoda: Trypanorhyncha: Rhinoptericolidae) from Hawaiian fishes.

PubMed

Palm, Harry W

2010-02-01

A new trypanorhynch cestode from Hawaiian waters is described based on specimens in the collection of the Meguro Parasitological Museum, Tokyo, and newly collected specimens. Nataliella marcelli n. g., n. sp. is characterised by its elongate, craspedote scolex with four small, ear-shaped bothria, an elongate pars vaginalis and long bulbs. The homeoacanthous homeomorphous metabasal armature is comprised of five or six slender, solid hooks per half spiral row. A distinctive basal armature is present, including a combination of six characteristically shaped macrohooks not previously described for trypanorhynchs. The surface ultrastructure consists of gladiate spiniform microtriches that cover the distal and proximal bothrial surface and filiform microtriches on the scolex peduncle. The adults are not known. Nataliella is assigned to the family Rhinoptericolidae Carvajal & Campbell, 1975 based on its possession of four bothria, prebulbar organs and no chainette or intercalary hooks. The family diagnosis is amended to accommodate the new genus. Rhinoptericola megacantha Carvajal & Campbell, 1975 is considered the most closely related species, a position that has been confirmed by molecular analyses of the SSU and LSU rDNA. Nataliella n. g. is intermediate in morphology between the homeoacanth family Tentaculariidae Poche, 1926 (superfamily Tentacularioidea) and the Rhinoptericolidae and other eutetrarhynchid genera (superfamily Eutetrarhynchoidea), sharing characters of both superfamilies.

Prevalence and diversity of gastrointestinal helminths in free-ranging Asian house shrew (Suncus murinus) in Bangladesh

PubMed Central

Rahman, Mizanur; Islam, Shariful; Masuduzzaman, Md.; Alam, Mahabub; Chawdhury, Mohammad Nizam Uddin; Ferdous, Jinnat; Islam, Md. Nurul; Hassan, Mohammad Mahmudul; Hossain, Mohammad Alamgir; Islam, Ariful

2018-01-01

Background and Aim Asian house shrew (Suncus murinus), a widely distributed small mammal in the South Asian region, can carry helminths of zoonotic importance. The aim of the study was to know the prevalence and diversity of gastrointestinal (GI) helminths in free-ranging Asian house shrew (S. murinus) in Bangladesh. Materials and Methods A total of 86 Asian house shrews were captured from forest areas and other habitats of Bangladesh in 2015. Gross examination of the whole GI tract was performed for gross helminth detection, and coproscopy was done for identification of specific eggs or larvae. Results The overall prevalence of GI helminth was 77.9% (67/86), with six species including nematodes (3), cestodes (2), and trematodes (1). Of the detected helminths, the dominant parasitic group was from the genus Hymenolepis spp.(59%), followed by Strongyloides spp.(17%), Capillaria spp. (10%), Physaloptera spp. (3%), and Echinostoma spp.(3%). Conclusion The finding shows that the presence of potential zoonotic parasites (Hymenolepis spp. and Capillaria spp.) in Asian house shrew is ubiquitous in all types of habitat (forest land, cropland and dwelling) in Bangladesh. Therefore, further investigation is crucial to examine their role in the transmission of human helminthiasis. PMID:29805224

Molecular identification of Echinococcus granulosus isolates from ruminants in Greece.

PubMed

Roinioti, Erifylli; Papathanassopoulou, Aegli; Theodoropoulou, Ioanna; Simsek, Sami; Theodoropoulos, Georgios

2016-08-15

Cystic echinococcosis is a parasitic disease caused by Echinococcus granulosus, a cestode with worldwide distribution. Data on the circulating Echinococcus granulosus genotypes in Greek livestock is scant. The aim of the present study was to conduct a genetic analysis of 82 Echinococcus granulosus isolates from ruminants in Greece, including areas which until today have not been the subject of studies. The analysis relied on a PCR assay targeting cytochrome c oxidase, subunit 1 gene (CO1), followed by bidirectional sequence analysis of the amplification product. Eighty (n=80) of the 82 (97.6%) isolates were allocated to Echinococcus granulosus sensu stricto (G1-G3) and were classified in 13 distinct haplotypes (9 common and 4 novel) with 12 polymorphic sites. The presence of the dominant haplotype EG1 as was documented in the European populations, was indicated in the country. Almost all regions shared the same common haplotype. In comparison to this predominant haplotype, the number of the nucleotide changes in all the other haplotypes ranged from 1 to 5. All nucleotide changes proved to be transitions (A↔G or C↔T). Two fertile hydatid cysts of sheep origin in different areas (Arkadia, Ilia) of the Peloponnese were identified as Echinococcus canadensis (G7 genotype). Copyright © 2016 Elsevier B.V. All rights reserved.

Purification and characterization of Taenia crassiceps cysticerci thioredoxin: insight into thioredoxin-glutathione-reductase (TGR) substrate recognition.

PubMed

Martínez-González, J J; Guevara-Flores, A; Rendón, J L; Sosa-Peinado, A; Del Arenal Mena, I P

2015-04-01

Thioredoxin (Trx) is an oxidoreductase central to redox homeostasis in cells and is involved in the regulation of protein activity through thiol/disulfide exchanges. Based on these facts, our goal was to purify and characterize cytosolic thioredoxin from Taenia crassiceps cysticerci, as well as to study its behavior as a substrate of thioredoxin-glutathione reductase (TGR). The enzyme was purified >133-fold with a total yield of 9.7%. A molecular mass of 11.7kDa and a pI of 4.84 were measured. Native electrophoresis was used to identify the oxidized and reduced forms of the monomer as well as the presence of a homodimer. In addition to the catalytic site cysteines, cysticerci thioredoxin contains Cys28 and Cys65 residues conserved in previously sequenced cestode thioredoxins. The following kinetic parameters were obtained for the substrate of TGR: a Km of 3.1μM, a kcat of 10s(-1) and a catalytic efficiency of 3.2×10(6)M(-1)s(-1). The negative patch around the α3-helix of Trx is involved in the interaction with TGR and suggests variable specificity and catalytic efficiency of the reductase toward thioredoxins of different origins. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Molecular identification of Taenia spp. in the Eurasian lynx (Lynx lynx) from Finland.

PubMed

Lavikainen, A; Haukisalmi, V; Deksne, G; Holmala, K; Lejeune, M; Isomursu, M; Jokelainen, P; Näreaho, A; Laakkonen, J; Hoberg, E P; Sukura, A

2013-04-01

Cestodes of the genus Taenia are parasites of mammals, with mainly carnivores as definitive and herbivores as intermediate hosts. Various medium-sized cats, Lynx spp., are involved in the life cycles of several species of Taenia. The aim of the present study was to identify Taenia tapeworms in the Eurasian lynx (Lynx lynx) from Finland. In total, 135 tapeworms from 72 lynx were subjected to molecular identification based on sequences of 2 mtDNA regions, the cytochrome c oxidase subunit 1 and the NADH dehydrogenase subunit 1 genes. Available morphological characters of the rostellar hooks and strobila were compared. Two species of Taenia were found: T. laticollis (127 samples) and an unknown Taenia sp. (5 samples). The latter could not be identified to species based on mtDNA, and the rostellar hooks were short relative to those described among other Taenia spp. recorded in felids from the Holarctic region. In the phylogenetic analyses of mtDNA sequences, T. laticollis was placed as a sister species of T. macrocystis, and the unknown Taenia sp. was closely related to T. hydatigena and T. regis. Our analyses suggest that these distinct taeniid tapeworms represent a putative new species of Taenia. The only currently recognized definitive host is L. lynx and the intermediate host is unknown.

First Record of Raillietina celebensis (Cestoda: Cyclophyllidea) in South America: Redescription and Phylogeny.

PubMed

de Oliveira Simões, Raquel; Simões, Susana Balmant Enrique; Luque, José Luis; Iñiguez, Alena Mayo; Júnior, Arnaldo Maldonado

2017-08-01

Raillietina celebensis is a cestode that parasitizes the small intestine of rats and humans. Here, we detail the morphology and morphometry of R. celebensis based on specimens collected from Rattus norvegicus in the municipality of São Gonçalo, state of Rio de Janeiro, Brazil, by light and confocal scanning laser microscopies and also report the results of molecular phylogenetic analyses to determine its relationships within the family Davaineidae. Analysis of the number and size of testes, number and shape of rostellar hooks, cirrus sac length, capsules and eggs per capsule, and morphology of the mature proglottid allowed concluding that the present specimens constitute a new record of R. celebensis in South America. Our genetic and phylogenetic analyses, based on the partial small subunit 18S rRNA gene, revealed R. celebensis to be in the family Davaineidae within the genus Raillietina, in agreement with the morphological taxonomy. Phylogenetic trees obtained by neighbor-joining and maximum likelihood methods demonstrated R. celebensis as a unique taxonomic unit, and also demonstrated some taxonomic inconsistences. The incorporation of Brazilian R. celebensis sequences derived from mammals in the phylogeny of davaineids is consistent with the assertion that neither Raillietina nor Fuhrmannetta can be supported as distinct genera.

Ontogenetic dynamics of infection with Diphyllobothrium spp. cestodes in sympatric Arctic charr Salvelinus alpinus (L.) and brown trout Salmo trutta L.

USGS Publications Warehouse

Henrickson, Eirik H.; Knudsen, Rune; Kristoffersen, Roar; Kuris, Armand M.; Lafferty, Kevin D.; Siwertsson, Anna; Amundsen, Per-Arne

2016-01-01

The trophic niches of Arctic charr and brown trout differ when the species occur in sympatry. Their trophically transmitted parasites are expected to reflect these differences. Here, we investigate how the infections of Diphyllobothrium dendriticum and D. ditremum differ between charr and trout. These tapeworms use copepods as their first intermediate hosts and fish can become infected as second intermediate hosts by consuming either infected copepods or infected fish. We examined 767 charr and 368 trout for Diphyllobothrium plerocercoids in a subarctic lake. The prevalence of D. ditremum was higher in charr (61.5%) than in trout, (39.5%), but the prevalence of D. dendriticum was higher in trout (31.2%) than in charr (19.3%). Diphyllobothrium spp. intensities were elevated in trout compared to charr, particularly for D. dendriticum. Large fish with massive parasite burdens were responsible for the high Diphyllobothrium spp. loads in trout. We hypothesize that fish prey may be the most important source for the Diphyllobothrium spp. infections in trout, whereas charr predominantly acquire Diphyllobothrium spp. by feeding on copepods. Our findings support previous suggestions that the ability to establish in a second piscine host is greater for D. dendriticum than for D. ditremum.

Effects of fish species composition on Diphyllobothrium spp. infections in brown trout - is three-spined stickleback a key species?

PubMed

Kuhn, J A; Frainer, A; Knudsen, R; Kristoffersen, R; Amundsen, P-A

2016-11-01

Subarctic populations of brown trout (Salmo trutta) are often heavily infected with cestodes of the genus Diphyllobothrium, assumedly because of their piscivorous behaviour. This study explores possible associations between availability of fish prey and Diphyllobothrium spp. infections in lacustrine trout populations. Trout in (i) allopatry (group T); (ii) sympatry with Arctic charr (Salvelinus alpinus) (group TC); and (iii) sympatry with charr and three-spined stickleback (Gasterosteus aculeatus) (group TCS) were contrasted. Mean abundance and intensity of Diphyllobothrium spp. were higher in group TCS compared to groups TC and T. Prevalence, however, was similarly higher in groups TCS and TC compared to group T. Zero-altered negative binomial modelling identified the lowest probability of infection in group T and similar probabilities of infection in groups TC and TCS, whereas the highest intensity was predicted in group TCS. The most infected trout were from the group co-occurring with stickleback (TCS), possibly due to a higher availability of fish prey. In conclusion, our study demonstrates elevated Diphyllobothrium spp. infections in lacustrine trout populations where fish prey are available and suggests that highly available and easily caught stickleback prey may play a key role in the transmission of Diphyllobothrium spp. parasite larvae. © 2016 John Wiley & Sons Ltd.

Parasites of Bloater Coregonus hoyi (Salmonidae) from Lake Michigan, U.S.A

USGS Publications Warehouse

Madenjian, Charles P.; Muzzall, Patrick M.

2013-01-01

In total, 158 bloaters Coregonus hoyi collected in September and October 2011 from 4 Lake Michigan, U.S.A., ports were examined for parasites. The ports included Waukegan (WK), Illinois; Port Washington (PW) and Sturgeon Bay (SB), Wisconsin; and Saugatuck (SG), Michigan. Parasites found in bloaters by port were cestodes Cyathocephalus truncatus (WK, PW, and SB) and Eubothrium salvelini (WK, PW, SB, and SG); the nematode Cystidicola farionis (WK, PW, SB, and SG); acanthocephalans Acanthocephalus dirus (WK and PW), Echinorhynchus salmonis (WK, PW, and SB), and Neoechinorhynchus tumidus (SB); and the copepod Salmincola corpulentus (WK and PW). Gravid individuals of all parasite species were found except for E. salvelini and A. dirus. Cystidicola farionis had the highest prevalence at each port, and the highest mean intensity and mean abundance at PW. The numbers of C. farionis at PW were significantly higher than those at WK and SB. Echinorhynchus salvelini had the highest mean intensities and mean abundances at WK, SB, and SG. The values for parasite species richness in bloaters were similar among ports. The total numbers of parasites were similar between WK and PW, but they were higher at these ports than at SB. The parasite faunas of bloaters were characterized by autogenic helminth species.

A new monozoic tapeworm, Parabreviscolex niepini n. g., n. sp. (Cestoda: Caryophyllidea), from schizothoracine fishes (Cyprinidae: Schizothoracinae) in Tibet, China.

PubMed

Xi, Bing-Wen; Oros, Mikuláš; Chen, Kai; Xie, Jun

2018-02-01

A new monozoic cestode, Parabreviscolex niepini n. gen. and n. sp. (Cestoda: Caryophyllidea), is described from the type-host Schizopygopsis younghusbandi Regan, 1905 (Cyprinidae: Schizothoracinae) and Schizothorax waltoni Regan, 1905 (Cyprinidae: Schizothoracinae) in the Yarlung Tsangpo River, the upper tributary of the Brahmaputra River on the Tibetan Plateau. The new genus is placed in the Capingentidae because the vitellarium is situated partly in the medullary and cortical parenchyma, i.e., neither completely external nor internal to inner longitudinal muscles. Parabreviscolex n. gen. is characterized by possessing an afossate and cuneiform scolex; numerous vitelline follicles and testes present immediately after the scolex, and spread backward near the cirrus sac; the uterus does not loop anterior to the cirrus sac; genital pores separate, opening to the common genital atrium; the pre-ovarian vitelline follicles lateral and median, post-ovarian vitelline follicles present; ovary H-shaped, compact, and ovarian arms long, anteriorly reaching the cirrus sac. Homology search by the basic local alignment search tool (BLAST) showed that the partial 18S rDNA and complete mtDNA cox-1 sequences obtained in this report were not consistent with any sequences available in GenBank, and molecular phylogenetic analyses revealed Parabreviscolex formed a separated long branch within the caryophyllideans from cyprinids.

Population expansion and individual age affect endoparasite richness and diversity in a recolonising large carnivore population

NASA Astrophysics Data System (ADS)

Lesniak, Ines; Heckmann, Ilja; Heitlinger, Emanuel; Szentiks, Claudia A.; Nowak, Carsten; Harms, Verena; Jarausch, Anne; Reinhardt, Ilka; Kluth, Gesa; Hofer, Heribert; Krone, Oliver

2017-01-01

The recent recolonisation of the Central European lowland (CEL) by the grey wolf (Canis lupus) provides an excellent opportunity to study the effect of founder events on endoparasite diversity. Which role do prey and predator populations play in the re-establishment of endoparasite life cycles? Which intrinsic and extrinsic factors control individual endoparasite diversity in an expanding host population? In 53 individually known CEL wolves sampled in Germany, we revealed a community of four cestode, eight nematode, one trematode and 12 potential Sarcocystis species through molecular genetic techniques. Infections with zoonotic Echinococcus multilocularis, Trichinella britovi and T. spiralis occurred as single cases. Per capita endoparasite species richness and diversity significantly increased with population size and changed with age, whereas sex, microsatellite heterozygosity, and geographic origin had no effect. Tapeworm abundance (Taenia spp.) was significantly higher in immigrants than natives. Metacestode prevalence was slightly higher in ungulates from wolf territories than from control areas elsewhere. Even though alternative canid definitive hosts might also play a role within the investigated parasite life cycles, our findings indicate that (1) immigrated wolves increase parasite diversity in German packs, and (2) prevalence of wolf-associated parasites had declined during wolf absence and has now risen during recolonisation.

Helminths of three species of opossums (Mammalia, Didelphidae) from Mexico

PubMed Central

Acosta-Virgen, Karla; López-Caballero, Jorge; García-Prieto, Luis; Mata-López, Rosario

2015-01-01

Abstract From August 2011 to November 2013, 68 opossums (8 Didelphis sp., 40 Didelphis virginiana, 15 Didelphis marsupialis, and 5 Philander opossum) were collected in 18 localities from 12 Mexican states. A total of 12,188 helminths representing 21 taxa were identified (6 trematodes, 2 cestodes, 3 acanthocephalans and 10 nematodes). Sixty-six new locality records, 9 new host records, and one species, the trematode Brachylaima didelphus, is added to the composition of the helminth fauna of the opossums in Mexico. These data, in conjunction with previous records, bring the number of taxa parasitizing the Mexican terrestrial marsupials to 41. Among these species, we recognized a group of helminths typical of didelphids in other parts of the Americas. This group is constituted by the trematode Rhopalias coronatus, the acanthocephalan Oligacanthorhynchus microcephalus and the nematodes Cruzia tentaculata, Gnathostoma turgidum, and Turgida turgida. In general, the helminth fauna of each didelphid species showed a stable taxonomic composition with respect to previously sampled sites. This situation suggests that the rate of accumulation of helminth species in the inventory of these 3 species of terrestrial marsupials in the Neotropical portion of Mexico is decreasing; however, new samplings in the Nearctic portion of this country will probably increase the richness of the helminthological inventory of this group of mammals. PMID:26257556

Intestinal parasites of endangered orangutans (Pongo pygmaeus) in Central and East Kalimantan, Borneo, Indonesia.

PubMed

Labes, E M; Hegglin, D; Grimm, F; Nurcahyo, W; Harrison, M E; Bastian, M L; Deplazes, P

2010-01-01

Faecal samples from 163 captive and semi-captive individuals, 61 samples from wild individuals and 38 samples from captive groups of Bornean orangutans (Pongo pygmaeus) in Kalimantan, Indonesia, were collected during one rainy season (November 2005-May 2006) and screened for intestinal parasites using sodium acetate-acetic acid-formalin-concentration (SAFC), sedimentation, flotation, McMaster- and Baermann techniques. We aimed to identify factors influencing infection risk for specific intestinal parasites in wild orangutans and individuals living in captivity. Various genera of Protozoa (including Entamoeba, Endolimax, Iodamoeba, Balantidium, Giardia and Blastocystis), nematodes (such as Strongyloides, Trichuris, Ascaris, Enterobius, Trichostrongylus and hookworms) and one trematode (a dicrocoeliid) were identified. For the first time, the cestode Hymenolepis was detected in orangutans. Highest prevalences were found for Strongyloides (individuals 37%; groups 58%), hookworms (41%; 58%), Balantidium (40%; 61%), Entamoeba coli (29%; 53%) and a trichostrongylid (13%; 32%). In re-introduction centres, infants were at higher risk of infection with Strongyloides than adults. Infection risk for hookworms was significantly higher in wild males compared with females. In groups, the centres themselves had a significant influence on the infection risk for Balantidium. Ranging patterns of wild orangutans, overcrowding in captivity and a shift of age composition in favour of immatures seemed to be the most likely factors leading to these results.

Population expansion and individual age affect endoparasite richness and diversity in a recolonising large carnivore population.

PubMed

Lesniak, Ines; Heckmann, Ilja; Heitlinger, Emanuel; Szentiks, Claudia A; Nowak, Carsten; Harms, Verena; Jarausch, Anne; Reinhardt, Ilka; Kluth, Gesa; Hofer, Heribert; Krone, Oliver

2017-01-27

The recent recolonisation of the Central European lowland (CEL) by the grey wolf (Canis lupus) provides an excellent opportunity to study the effect of founder events on endoparasite diversity. Which role do prey and predator populations play in the re-establishment of endoparasite life cycles? Which intrinsic and extrinsic factors control individual endoparasite diversity in an expanding host population? In 53 individually known CEL wolves sampled in Germany, we revealed a community of four cestode, eight nematode, one trematode and 12 potential Sarcocystis species through molecular genetic techniques. Infections with zoonotic Echinococcus multilocularis, Trichinella britovi and T. spiralis occurred as single cases. Per capita endoparasite species richness and diversity significantly increased with population size and changed with age, whereas sex, microsatellite heterozygosity, and geographic origin had no effect. Tapeworm abundance (Taenia spp.) was significantly higher in immigrants than natives. Metacestode prevalence was slightly higher in ungulates from wolf territories than from control areas elsewhere. Even though alternative canid definitive hosts might also play a role within the investigated parasite life cycles, our findings indicate that (1) immigrated wolves increase parasite diversity in German packs, and (2) prevalence of wolf-associated parasites had declined during wolf absence and has now risen during recolonisation.

Population expansion and individual age affect endoparasite richness and diversity in a recolonising large carnivore population

PubMed Central

Lesniak, Ines; Heckmann, Ilja; Heitlinger, Emanuel; Szentiks, Claudia A.; Nowak, Carsten; Harms, Verena; Jarausch, Anne; Reinhardt, Ilka; Kluth, Gesa; Hofer, Heribert; Krone, Oliver

2017-01-01

The recent recolonisation of the Central European lowland (CEL) by the grey wolf (Canis lupus) provides an excellent opportunity to study the effect of founder events on endoparasite diversity. Which role do prey and predator populations play in the re-establishment of endoparasite life cycles? Which intrinsic and extrinsic factors control individual endoparasite diversity in an expanding host population? In 53 individually known CEL wolves sampled in Germany, we revealed a community of four cestode, eight nematode, one trematode and 12 potential Sarcocystis species through molecular genetic techniques. Infections with zoonotic Echinococcus multilocularis, Trichinella britovi and T. spiralis occurred as single cases. Per capita endoparasite species richness and diversity significantly increased with population size and changed with age, whereas sex, microsatellite heterozygosity, and geographic origin had no effect. Tapeworm abundance (Taenia spp.) was significantly higher in immigrants than natives. Metacestode prevalence was slightly higher in ungulates from wolf territories than from control areas elsewhere. Even though alternative canid definitive hosts might also play a role within the investigated parasite life cycles, our findings indicate that (1) immigrated wolves increase parasite diversity in German packs, and (2) prevalence of wolf-associated parasites had declined during wolf absence and has now risen during recolonisation. PMID:28128348

Recombinase Polymerase Amplification Compared to Real-Time Polymerase Chain Reaction Test for the Detection of Fasciola hepatica in Human Stool

PubMed Central

Cabada, Miguel M.; Malaga, Jose L.; Castellanos-Gonzalez, Alejandro; Bagwell, Kelli A.; Naeger, Patrick A.; Rogers, Hayley K.; Maharsi, Safa; Mbaka, Maryann; White, A. Clinton

2017-01-01

Fasciola hepatica is the most widely distributed trematode infection in the world. Control efforts may be hindered by the lack of diagnostic capacity especially in remote endemic areas. Polymerase chain reaction (PCR)–based methods offer high sensitivity and specificity but require expensive technology. However, the recombinase polymerase amplification (RPA) is an efficient isothermal method that eliminates the need for a thermal cycler and has a high deployment potential to resource-limited settings. We report on the characterization of RPA and PCR tests to detect Fasciola infection in clinical stool samples with low egg burdens. The sensitivity of the RPA and PCR were 87% and 66%, respectively. Both tests were 100% specific showing no cross-reactivity with trematode, cestode, or nematode parasites. In addition, RPA and PCR were able to detect 47% and 26% of infections not detected by microscopy, respectively. The RPA adapted to a lateral flow platform was more sensitive than gel-based detection of the reaction products. In conclusion, the Fasciola RPA is a highly sensitive and specific test to diagnose chronic infection using stool samples. The Fasciola RPA lateral flow has the potential for deployment to endemic areas after further characterization. PMID:27821691

Expression of the histone chaperone SET/TAF-Iβ during the strobilation process of Mesocestoides corti (Platyhelminthes, Cestoda).

PubMed

Costa, Caroline B; Monteiro, Karina M; Teichmann, Aline; da Silva, Edileuza D; Lorenzatto, Karina R; Cancela, Martín; Paes, Jéssica A; Benitz, André de N D; Castillo, Estela; Margis, Rogério; Zaha, Arnaldo; Ferreira, Henrique B

2015-08-01

The histone chaperone SET/TAF-Iβ is implicated in processes of chromatin remodelling and gene expression regulation. It has been associated with the control of developmental processes, but little is known about its function in helminth parasites. In Mesocestoides corti, a partial cDNA sequence related to SET/TAF-Iβ was isolated in a screening for genes differentially expressed in larvae (tetrathyridia) and adult worms. Here, the full-length coding sequence of the M. corti SET/TAF-Iβ gene was analysed and the encoded protein (McSET/TAF) was compared with orthologous sequences, showing that McSET/TAF can be regarded as a SET/TAF-Iβ family member, with a typical nucleosome-assembly protein (NAP) domain and an acidic tail. The expression patterns of the McSET/TAF gene and protein were investigated during the strobilation process by RT-qPCR, using a set of five reference genes, and by immunoblot and immunofluorescence, using monospecific polyclonal antibodies. A gradual increase in McSET/TAF transcripts and McSET/TAF protein was observed upon development induction by trypsin, demonstrating McSET/TAF differential expression during strobilation. These results provided the first evidence for the involvement of a protein from the NAP family of epigenetic effectors in the regulation of cestode development.

Mulinia lateralis (Mollusca: Bivalvia) die-off in South Carolina: discovery of a vector for two elasmobranch cestode species.

PubMed

de Buron, Isaure; Roth, Patricia B; Bergquist, Derk C; Knott, David M

2013-02-01

Unexplained and episodic die-offs of the dwarf surf clam, Mulinia lateralis , have been reported on the West Atlantic coast, with such an occurrence in South Carolina in June 2010. A sample of live clams from the 2010 South Carolina event was collected, and 200 clams were measured and necropsied. Two species of tapeworm larvae were observed. Plerocercoids (Duplicibothrium sp.) occupied the digestive gland ducts, and merocercoids (Rhodobothrium sp.) were found beneath the mantle. Specimens of both species were sequenced to obtain partial 28S rRNA gene sequences, and they were identified as the tetraphyllidean D. minutum and the rhinebothriidean R. paucitesticulare, based on an NCBI Standard Nucleotide BLAST search. Of the 200 clams, 2.1% were infected with merocercoids (mean intensity 1.3 ± 0.2) and 75% with plerocercoids (mean intensity 4.3 ± 3.7). Intensity of infection by plerocercoids increased significantly with individual shell length. The presence of plerocercoids was associated with enlargement of the digestive gland ducts, but no other pathology was observed. Because uninfected clams were abundant among the stranded molluscs, these parasites are not considered to be the causative agent of the die-off. This is a new host record for both elasmobranch tapeworms.

Fish innate immunity against intestinal helminths.

PubMed

Dezfuli, B S; Bosi, G; DePasquale, J A; Manera, M; Giari, L

2016-03-01

Most individual fish in farmed and wild populations are infected with parasites. Upon dissection of fish, helminths from gut are often easily visible. Enteric helminths include several species of digeneans, cestodes, acanthocephalans and nematodes. Some insights into biology, morphology and histopathological effects of the main fish enteric helminths taxa will be described here. The immune system of fish, as that of other vertebrates, can be subdivided into specific and aspecific types, which in vivo act in concert with each other and indeed are interdependent in many ways. Beyond the small number of well-described models that exist, research focusing on innate immunity in fish against parasitic infections is lacking. Enteric helminths frequently cause inflammation of the digestive tract, resulting in a series of chemical and morphological changes in the affected tissues and inducing leukocyte migration to the site of infection. This review provides an overview on the aspecific defence mechanisms of fish intestine against helminths. Emphasis will be placed on the immune cellular response involving mast cells, neutrophils, macrophages, rodlet cells and mucous cells against enteric helminths. Given the relative importance of innate immunity in fish, and the magnitude of economic loss in aquaculture as a consequence of disease, this area deserves considerable attention and support. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigation of gastrointestinal parasites of dairy cattle around Taiwan.

PubMed

Huang, Chiu-Chen; Wang, Lian-Chen; Pan, Chien-Hung; Yang, Cheng-Hsiung; Lai, Cheng-Hung

2014-02-01

Parasitic nematodes are one of the most important causes of production losses in most cattle-producing countries of the world. The aim of the present study is to make a through estimate of helminth and protozoan infection prevalence in dairy cattle around Taiwan. Coprological techniques, including direct fecal smear, simple flotation, and simple sedimentation, were used to detect gastrointestinal helminths and protozoan in dairy cattle. A total of 1259 rectal fecal samples were collected from Holstein dairy cattle at 94 farms in 13 counties in Taiwan. The overall prevalence of gastrointestinal parasitic infection was 86.9%. The infection rates of protozoa, nematodes, trematodes, and cestodes were 81.3%, 7.9%, 1.6%, and 0.6%, respectively. Among all parasites, Buxtonella sulcata (61.7%) was the most predominant one, followed with Cryptosporidium spp. (32.6%) and Eimeria spp. (11.8%). There were significant differences in the prevalence of protozoa and nematodes between different age groups and distributional area groups. The present study demonstrated that gastrointestinal parasitic infections occur frequently in dairy cattle around Taiwan, especially protozoan infections. The results indicated that a superior management system and regular anthelmintic treatment should be used for the control of parasitic infections in dairy cattle farms. Copyright © 2012. Published by Elsevier B.V.

Rickettsiae, protozoa, and opisthokonta/metazoa.

PubMed

Schmutzhard, Erich; Helbok, Raimund

2014-01-01

Rhizobiales (formerly named Rickettsiales) cause in rare instances meningitis and meningovasculitis, respectively. In case of history of exposure, infection by Rhizobiales needs to be considered since both diagnosis and therapy may be extremely difficult and pathogen-specific. The same applies to protozoa; in this chapter, Babesia species, free-living amoebae and Entamoeba histolytica infection, including severe meningitis and brain abscess, infection by Trypanosoma species (South American and African trypanosomiasis) are discussed with respect to history, epidemiology, clinical signs, and symptoms as well as differential diagnosis and therapy. Parasitic flatworms and roundworms, potentially able to invade the central nervous system, trematodes (flukes), cestodes (in particular, Cysticercus cellulosae), but also nematodes (in particular, Strongyloides spp. in the immunocompromised) are of worldwide importance. In contrast, filarial worms, Toxocara spp., Trichinella spp., Gnathostoma and Angiostrongylus spp. are seen only in certain geographically confined areas. Even more regionally confined are infestations of the central nervous system by metazoa, in particular, tongue worms (=arthropods) or larvae of flies (=maggots). The aim of this chapter is (1) to alert the neurologist to these infections, and (2) to enable the attending emergency neurologist to take a knowledgeable history, with an emphasis on epidemiology, clinical signs, and symptoms as well as therapeutic management possibilities. © 2014 Elsevier B.V. All rights reserved.

Taxonomic composition and endemism of the helminth fauna of freshwater fishes of Mexico.

PubMed

Salgado-Maldonado, Guillermo; Quiroz-Martínez, Benjamín

2013-01-01

We examine the taxonomic composition and endemism of adult helminth parasites of freshwater fishes of Mexico, with regard to the main hydrological basins of the country. A presence-absence matrix, including every species of adult helminth parasites of freshwater fishes from 23 Mexican hydrological basins was compiled and examined in this paper. The helminth fauna of freshwater fishes of Mexico consists of a large group of Central American Neotropical species (S = 119) and another set, less rich of Nearctic species (S = 48), which are distributed along with the families of its fish hosts; insufficient data preclude the assignation of three species. This fauna is composed predominantly by nematodes, trematodes, and monogeneans, which together contributed 86 % of the total species recorded; cestodes and acanthocephalans being the taxa with the least species recorded. Current data suggests a 22 % (37/170) endemism amongst helminths of freshwater fishes of Mexico. Data suggests that the isolation of bodies of water in the Mexican territory, mostly in the Neotropical areas of southeastern Mexico and in the central Altiplano Mexicano (Mexican Highland Plateau), with well delimited basins separated by orographic features, provided peculiar conditions that have been conducive to the diversification of a unique helminth fauna.

Host specificity and the structure of helminth parasite communities of fishes in a Neotropical river in Mexico

PubMed Central

Salgado-Maldonado, Guillermo; Novelo-Turcotte, María Teresa; Caspeta-Mandujano, Juan Manuel; Vazquez-Hurtado, Gabriela; Quiroz-Martínez, Benjamin; Mercado-Silva, Norman; Favila, Mario

2016-01-01

In a tropical locality of Río La Antigua, Veracruz, Mexico, 11 fish species, represented by 244 individual fish from six freshwater fish families living sympatrically and synchronically, were examined for helminth parasites. A total of 36 taxa of helminths were recorded, 24 autogenic and 12 allogenic forms, including 6 monogeneans, 14 trematodes, 1 cestode, and 15 nematodes. Most helminth taxa were recovered for 10/11 of the component communities we analyzed. The results contribute empirical evidence that host specificity is an important force in the development of helminth communities of freshwater fishes. Each fish family has their own set of parasites, host species belonging to the same taxon share parasite species. High component community similarity among related host species was recorded, demonstrated by high prevalence and abundance, as well as dominance, of autogenic specialist species in each component community. Most autogenic helminth species are numerically and reproductively successful in relatively few host species. Autogenic helminths common in one host species are not common in others. Our findings give empirical support to the idea that low levels of sharing of parasites favor animal coexistence and high species richness, because large phylogenetic differences allow potentially competing animals to consume the same resources without being sensitive of another’s parasites. PMID:28004635

A new genus of proteocephalid tapeworm (Cestoda) from the marbled swamp eel Synbranchus marmoratus Bloch (Synbranchiformes: Synbranchidae) in the River Paraná basin, Argentina.

PubMed

Arredondo, Nathalia J; Alves, Philippe Vieira; Gil de Pertierra, Alicia A

2017-05-05

Synbranchiella gen. n. is proposed to accommodate Synbranchiella mabelae sp. n. (Proteocephalidae: Monticelliinae) from the intestine of the marbled swamp eel Synbranchus marmoratus Bloch, in the River Colastiné, a tributary of the middle River Paraná in Argentina. The new genus is placed in the Monticelliinae because of the cortical position of the genital organs. It differs from all known monticelliine genera by the following combination of characters: (i) scolex robust, with a conical apex, without metascolex; (ii) biloculate suckers with a conspicuous septum separating unequally-sized loculi and a robust non-adherent area, lacking free posterior margin; (iii) vitelline follicles in two narrow lateral bands, extended throughout the nearly entire proglottid length; (iv) vagina always anterior to the cirrus-sac, with an inconspicuous vaginal sphincter; (v) a genital pore pre-equatorial. Scanning electron microscopy revealed three types of microtriches on the tegument surface: acicular and capiliform filitriches and gladiate spinitriches. A phylogenetic analysis of the large subunit nuclear ribosomal RNA gene (lsrDNA, D1-D3 domains) confirms that S. mabelae represents an independent lineage within a large clade comprised mainly from Neotropical taxa parasitising catfishes. This is the second proteocephalidean cestode described from a Neotropical synbranchiform fish host.

Molecular characterization of the Indian poultry nodular tapeworm, Raillietina echinobothrida (Cestoda: Cyclophyllidea: Davaineidae) based on rDNA internal transcribed spacer 2 region.

PubMed

Ramnath; Jyrwa, D B; Dutta, A K; Das, B; Tandon, V

2014-03-01

The nodular tapeworm, Raillietina echinobothrida is a well studied avian gastrointestinal parasite of family Davaineidae (Cestoda: Cyclophyllidea). It is reported to be the largest in size and second most prevalent species infecting chicken in north-east India. In the present study, morphometrical methods coupled with the molecular analysis of the second internal transcribed spacer (ITS2) region of ribosomal DNA were employed for precise identification of the parasite. The annotated ITS2 region was found to be 446 bp long and further utilized to elucidate the phylogenetic relationships and its species-interrelationships at the molecular level. In phylogenetic analysis similar topology was observed among the trees obtained by distance-based neighbor-joining as well as character-based maximum parsimony tree building methods. The query sequence R. echinobothrida is well aligned and placed within the Davaineidae group, with all Raillietina species well separated from the other cyclophyllidean (taeniid and hymenolepid) cestodes, while Diphyllobothrium latum (Pseudophyllidea: Diphyllobothriidae) was rooted as an out-group. Sequence similarities indeed confirmed our hypothesis that Raillietina spp. are neighboring the position with other studied species of order Cyclophyllidea against the out-group order Pseudophyllidea. The present study strengthens the potential of ITS2 as a reliable marker for phylogenetic reconstructions.

A New Genus of Tapeworm (Cestoda: Onchoproteocephalidea) from Sawfish (Elasmobranchii: Pristidae).

PubMed

Caira, J N; Jensen, K; Fyler, C A

2018-04-01

Collections from the dwarf sawfish, Pristis clavata, near Darwin, Australia, in 1997 led to the discovery of the new onchoproteocephalidean genus Matticestus n. gen.-a taxon that has been referred to in molecular phylogenetic analyses in which it has been included as "New genus 8." Its type species, Matticestus anneae n. gen., n. sp., and a second species, Matticestus kathleenae n. sp., are described. Placement of this taxon in the Onchoproteocephalidea is supported morphologically in that both species bear a scolex with 4 bothridia each with a pair of bi-pronged hooks and spinitriches that extend throughout the length of the body. Sequence data for the D1-D3 region of the 28S rDNA gene also place the genus solidly among the other elasmobranch-hosted members of the order. The new genus differs from the other elasmobranch-hosted genera in the order in that its members possess a combination of biloculated bothridia with lateral lappets on the posterior margin of the anterior loculus and a pair of bi-pronged hooks with a distinctive configuration of tubercles and internal channels. Its members are also extremely small. In summary, Matticestus n. gen. is an unusually tiny, "spiny," genus of cestode that seems to exclusively parasitize sawfish of the genus Pristis.

Genetic polymorphism and population structure of Echinococcus ortleppi.

PubMed

Addy, F; Wassermann, M; Banda, F; Mbaya, H; Aschenborn, J; Aschenborn, O; Koskei, P; Umhang, G; DE LA Rue, M; Elmahdi, I E; Mackenstedt, U; Kern, P; Romig, T

2017-04-01

The zoonotic cestode Echinococcus ortleppi (Lopez-Neyra and Soler Planas, 1943) is mainly transmitted between dogs and cattle. It occurs worldwide but is only found sporadically in most regions, with the notable exception of parts of southern Africa and South America. Its epidemiology is little understood and the extent of intraspecific variability is unknown. We have analysed in the present study the genetic diversity among 178 E. ortleppi isolates from sub-Saharan Africa, Europe and South America using the complete mitochondrial cox1 (1608 bp) and nad1 (894 bp) DNA sequences. Genetic polymorphism within the loci revealed 15 cox1 and six nad1 haplotypes, respectively, and 20 haplotypes of the concatenated genes. Presence of most haplotypes was correlated to geographical regions, and only one haplotype had a wider spread in both eastern and southern Africa. Intraspecific microvariance was low in comparison with Echinococcus granulosus sensu stricto, despite the wide geographic range of examined isolates. In addition, the various sub-populations showed only subtle deviation from neutrality and were mostly genetically differentiated. This is the first insight into the population genetics of the enigmatic cattle adapted Echinococcus ortleppi. It, therefore, provides baseline data for biogeographical comparison among E. ortleppi endemic regions and for tracing its translocation paths.

Echinococcus multilocularis Leuckart, 1863 (Taeniidae): new data on sperm ultrastructure.

PubMed

Miquel, Jordi; Świderski, Zdzisław; Azzouz-Maache, Samira; Pétavy, Anne-Françoise

2016-06-01

The present study establishes the ultrastructural organisation of the mature spermatozoon of Echinococcus multilocularis, which is essential for future research on the location of specific proteins involved in the sperm development in this species and also in Echinococcus granulosus. Thus, the ultrastructural characteristics of the sperm cell are described by means of transmission electron microscopy. The spermatozoon of E. multilocularis is a filiform cell, which is tapered at both extremities and lacks mitochondria. It exhibits all the characteristics of type VII spermatozoon of tapeworms, namely a single axoneme, crested bodies, spiralled cortical microtubules and nucleus, a periaxonemal sheath and intracytoplasmic walls. Other characteristics observed in the male gamete are the presence of a >900-nm long apical cone in its anterior extremity and only the axoneme in its posterior extremity. The ultrastructural characters of the spermatozoon of E. multilocularis are compared with those of other cestodes studied to date, with particular emphasis on representatives of the genus Taenia. The most interesting finding concerns the presence of two helical crested bodies in E. multilocularis while in the studied species of Taenia, there is only one crested body. Future ultrastructural studies of other species of the genus Echinococcus would be of particular interest in order to confirm whether or not the presence of two crested bodies is a characteristic of this genus.

No effect of a parasite on reproduction in stickleback males: a laboratory artefact?

PubMed

Candolin, U; Voigt, H R

2001-04-01

Experiments are often carried out in the laboratory under artificial conditions. Although this can control for confounding factors, it may eliminate important factors that under natural conditions mediate the interaction under investigation. Here, we show that different results can be gained in the field and in the laboratory regarding host-parasite interaction. In the field, courting three-spined stickleback males, Gasterosteus aculeatus, were less often infected with plerocercoids of a cestode tapeworm, Schistocephalus solidus, than shoaling males. However, when a random sample of males was allowed to nest and court females in individual aquaria in the laboratory, both uninfected and infected males built nests and courted females. Moreover, while the few infected males that courted females in the field expressed less red nuptial coloration than uninfected courting males, there was no difference in redness between infected and uninfected males in the laboratory. We argue that the different results gained in the field and in the laboratory are due to differences in the cost of reproduction, due to differences in the resource pool of the males. The favourable conditions in the laboratory exclude factors such as predation risk, social interactions, and fluctuating environmental conditions that may use up resources in the field and mediate the effect of the parasite.

Overview of Zoonotic Diseases in Turkey: The One Health Concept and Future Threats.

PubMed

İnci, Abdullah; Doğanay, Mehmet; Özdarendeli, Aykut; Düzlü, Önder; Yıldırım, Alparslan

2018-03-01

Zoonotic infections are globally important diseases and lead to huge economic losses in both low- and middle-income and high-income countries. Global warming, environmental and ecological changes, illegal movement of animals and humans, regional civil wars, and poverty are predisposing factors for the emergence of zoonotic infections and their distribution worldwide; they are also a big threat for the future. In addition, environmental pollution and antimicrobial resistance are immense serious threats and dangers to prevent and control zoonotic infections. The natural location of Turkey allows many emerged or re-emerged infections with zoonotic characteristics by animal movements, such as bird immigrations, and by human movements due to civil wars as seen with regional refugees. Numerous zoonotic diseases, including 37 bacterial, 13 fungal, 29 viral, 28 parasitic (3 trematodes, 7 cestodes, 10 nematodes, and 8 protozoan), and totally 107 infections, have been reported from Turkey to date. Additionally, many ectoparasitic zoonoses within 15 different arthropod groups and one leech infestation have been reported from Turkey to date. The "One Health" initiative is particularly relevant for developing strategies to combat zoonotic diseases. In this article, we review the occurrence of zoonotic diseases in man and animals in Turkey in the light of the "One Health" perspective.

Helminths community of veterinary importance of livestock in relation to some ecological and biological factors.

PubMed

Ibrahim, Mohamed M; Ghamdi, Manea; Gahmdi, Mesfer

2008-01-01

The goals of this study were: (I) to report the helminth population in cattle, sheep and goats; (II) to determine the concentration and diversity of the population; and (III) to study the role of host age, host sex, diet and season in structuring the population. A total of 485 cattle, 1144 sheep and 989 goats were examined for helminth population for four seasons. The helminth population consisted of nine species, four trematodes, four cestodes and one nematode. The overall infection prevalence in cattle, sheep and goats was 12.92%, 18.63% and 13.45%, respectively. Echinococcus granulosus was the most prevalent parasite. The overall mean species concentration per host was 1.23, 0.95 and 0.53 in cattle, sheep and goats, respectively. Species concentration, prevalence and mean abundance varied significantly in relation to host age, sex, diet and season. In conclusion, the influence of the factors investigated on structuring the helminth population of livestock, varied from species to another. We cannot say if the low species concentration and the recorded infection rates observed in the present study are typical of the host species or if they are due to characteristics of the study area, since there is no data available for other host populations.

Helminth parasite communities of allopatric populations of the frog Leptodactylus podicipinus from Pantanal, Brazil.

PubMed

Campião, K M; da Silva, R J; Ferreira, V L

2014-03-01

Several factors may influence the structure of parasite communities in amphibian hosts. In this study, we describe the helminth parasites of three allopatric populations of the frog Leptodactylus podicipinus and test whether host size and sex were determinants of the structure and composition of the helminth communities. One hundred and twenty-three anurans were collected from three different study sites within the Pantanal wetlands and surveyed for helminth parasites. We found 14 helminth taxa: 7 species of nematodes, 4 species of trematodes, 1 species of cestodes, 1 species of acanthocephalan and one unidentified cyst. Host sex and size did not cause significant differences in helminth abundance or richness. The structure of helminth communities from the three study sites varied in terms of species composition, abundance and diversity. Six out of 14 helminth taxa were found in the three localities. Among those, the nematodes Cosmocerca podicipinus and Rhabdias sp., the trematode Catadiscus propinquus and the helminth cyst showed significant differences in mean abundances. We suggest that such differences found among the three component communities are driven by biotic and abiotic factors operating locally. Moreover, these differences stress the importance of local conditions, such as hydrologic characteristics and landscape composition, on helminth community structure.

Endohelminths in Bird Hosts from Northern California and an Analysis of the Role of Life History Traits on Parasite Richness.

PubMed

Hannon, Emily R; Kinsella, John M; Calhoun, Dana M; Joseph, Maxwell B; Johnson, Pieter T J

2016-04-01

The life history characteristics of hosts often influence patterns of parasite infection either by affecting the likelihood of parasite exposure or the probability of infection after exposure. In birds, migratory behavior has been suggested to affect both the composition and abundance of parasites within a host, although whether migratory birds have more or fewer parasites is unclear. To help address these knowledge gaps, we collaborated with airports, animal rescue/rehabilitation centers, and hunter check stations in the San Francisco Bay Area of California to collect 57 raptors, egrets, herons, ducks, and other waterfowl for parasitological analysis. After dissections of the gastrointestinal tract of each host, we identified 64 taxa of parasites: 5 acanthocephalans, 24 nematodes, 8 cestodes, and 27 trematodes. We then used a generalized linear mixed model to determine how life history traits influenced parasite richness among bird hosts, while controlling for host phylogeny. Parasite richness was greater in birds that were migratory with larger clutch sizes and lower in birds that were herbivorous. The effects of clutch size and diet are consistent with previous studies and have been linked to immune function and parasite exposure, respectively, whereas the effect of migration supports the hypothesis of "migratory exposure" rather than that of "migratory escape."

Helminths in sympatric populations of mountain reedbuck (Redunca fulvorufula) and gray rhebok (Pelea capreolus) in South Africa.

PubMed

Taylor, W A; Boomker, J; Krecek, R C; Skinner, J D; Watermeyer, R

2005-08-01

Helminths of mountain reedbuck (Redunca fulvorufula fulvorufula) and gray rhebok (Pelea capreolus) were investigated in South Africa between June 1999 and February 2002. Forty-one mountain reedbuck were culled at Sterkfontein Dam Nature Reserve over 8 different periods, and 25 mountain reedbuck were culled at Tussen die Riviere Nature Reserve over 3 different periods. A total of 17 kinds of helminths were found at the 2 sites, including 15 nematodes, 1 trematode, and 1 cestode. At Sterkfontein, the most prevalent and abundant species were Cooperia yoshidai, Longistrongylus schrenki, and Haemonchus contortus, with the latter 2 being more abundant during November/December than at other times of the year, probably because infective larvae increased on pasture at that time. No statistical differences were found in parasite loads between male and female mountain reedbuck. No correlation was found between fecal egg counts and adult worm counts or between parasite counts and body condition. At Tussen die Riviere, helminths in mountain reedbuck were less prevalent and abundant than at Sterkfontein. The most important species were Nematodirus spathiger, Trichostrongylus falculatus, and Cooperia rotundispiculum. Four gray rhebok died of natural causes at Sterkfontein, from which 5 kinds of helminths were recovered, including C. yoshidai and Paracooperioides peleae.

Efficacy of condensed tannins against larval Hymenolepis diminuta (Cestoda) in vitro and in the intermediate host Tenebrio molitor (Coleoptera) in vivo.

PubMed

Dhakal, Suraj; Meyling, Nicolai V; Williams, Andrew R; Mueller-Harvey, Irene; Fryganas, Christos; Kapel, Christian M O; Fredensborg, Brian L

2015-01-15

Natural anti-parasitic compounds in plants such as condensed tannins (CT) have anthelmintic properties against a range of gastrointestinal nematodes, but for other helminths such effects are unexplored. The aim of this study was to assess the effects of CT from three different plant extracts in a model system employing the rat tapeworm, Hymenolepis diminuta, in its intermediate host, Tenebrio molitor. An in vitro study examined infectivity of H. diminuta cysticercoids (excystation success) isolated from infected beetles exposed to different concentrations of CT extracts from pine bark (PB) (Pinus sps), hazelnut pericarp (HN) (Corylus avellana) or white clover flowers (WC) (Trifolium repens), in comparison with the anthelmintic drug praziquantel (positive control). In the in vitro study, praziquantel and CT from all three plant extracts had dose-dependent inhibitory effects on cysticercoid excystation. The HN extract was most effective at inhibiting excystation, followed by PB and WC. An in vivo study was carried out on infected beetles (measured as cysticercoid establishment) fed different doses of PB, HN and praziquantel. There was a highly significant inhibitory effect of HN on cysticercoid development (p=0.0002). Overall, CT showed a promising anti-cestodal effect against the metacestode stage of H. diminuta. Copyright © 2014 Elsevier B.V. All rights reserved.

Parasites infecting the cultured oyster Crassostrea gasar (Adanson, 1757) in Northeast Brazil.

PubMed

Queiroga, Fernando Ramos; Vianna, Rogério Tubino; Vieira, Cairé Barreto; Farias, Natanael Dantas; Da Silva, Patricia Mirella

2015-05-01

The oyster Crassostrea gasar is a species widely used as food and a source of income for the local population of the estuaries of Northeast Brazil. Perkinsus marinus and Perkinsus olseni are deleterious parasites for oyster farming and were recently detected in Brazil. In this study, a histopathologic survey of the oyster C. gasar cultured in the estuary of the River Mamanguape (Paraíba State) was performed. Adult oysters were collected in December 2011 and March, May, August and October 2012 and processed for histology and Perkinsus sp. identification by molecular analyses. Histopathological analysis revealed the presence of parasitic organisms including viral gametocytic hypertrophy, prokaryote-like colonies, protozoans (Perkinsus sp. and Nematopsis sp.) and metazoans (Tylocephalum sp. and cestodes). Other commensal organisms were also detected (the protozoan Ancistrocoma sp. and the turbellarian Urastoma sp.). The protozoan parasite Perkinsus sp. had the highest overall prevalence among the symbiotic organisms studied (48.9%), followed by Nematopsis sp. (36.3%). The other organisms were only sporadically observed. Only the protozoan Perkinsus sp. caused alterations in the oysters' infected organs. Molecular analyses confirmed the presence of P. marinus, P. olseni and Perkinsus beihaiensis infecting the oyster C. gasar. This is the first report of P. beihaiensis in this oyster species.

Parasitic infection by larval helminths in Antarctic fishes: pathological changes and impact on the host body condition index

USGS Publications Warehouse

Santoro, Mario; Mattiucci, Simonetta; Work, Thierry M.; Cimmaruta, Roberta; Nardi, Valentina; Cipriani, Paolo; Bellisario, Bruno; Nascetti, Giuseppe

2013-01-01

We examined pathological changes and relationship between body condition index (BCI) and parasitic infection in 5 species of fish, including 42 icefish Chionodraco hamatus (Channichtyidae), 2 dragonfish Cygnodraco mawsoni (Bathydraconidae), 30 emerald rock cod Trematomus bernacchii, 46 striped rock cod T. hansoni and 9 dusty rock cod T. newnesi (Nototheniidae) from the Ross Sea, Antarctica. All parasites were identified by a combination of morphology and mtDNA cytochrome-oxidase-2 sequence (mtDNA cox2) analysis, except Contracaecum osculatum s.l., for which only the latter was used. Five larval taxa were associated with pathological changes including 2 sibling species (D and E) of the C. osculatum species complex and 3 cestodes including plerocercoids of a diphyllobothridean, and 2 tetraphyllidean forms including cercoids with monolocular and bilocular bothridia. The most heavily infected hosts were C. hamatus and C. mawsoni, with C. hamatus most often infected by C. osculatum sp. D and sp. E and diphyllobothrideans, while C. mawsoni was most often infected with tetraphyllidean forms. Histologically, all fish showed varying severity of chronic inflammation associated with larval forms of helminths. Diphyllobothrideans and C. osculatum spp. were located in gastric muscularis or liver and were associated with necrosis and mild to marked fibrosis. Moderate multifocal rectal mucosal chronic inflammation was associated with attached tetraphyllidean scolices. C. hamatus showed a strong negative correlation between BCI and parasite burden.

Echinococcus granulosus equinus: an ultrastructural study of the laminated layer, including changes on incubating cysts in various media.

PubMed

Richards, K S; Arme, C; Bridges, J F

1983-06-01

The microfibrillate component of the laminated layer of Echinococcus granulosus equinus contains, except for the zone adjacent to the germinal layer, aggregates of electron-dense bodies displaying a sub-structure of electron-lucent spheres. The tegumentary syncytial cytoplasm contains randomly distributed electron-dense granules, many occurring near the apical plasmalemma, although exocytosis was rarely seen. Granules, similar in size and sub-structure to the bodies of the aggregates, also occur in the internuncial connexions and tegumentary cytons, suggesting that they may be produced in the cytons and released into the laminated layer via the internuncial connexions and tegumentary cytoplasm. Cysts incubated for 0.5-2.5 h in serum- and non-serum-containing media showed differences from non-incubated cysts. The distal half of the syncytium contained a progressive increase in the number of granules (distal: proximal 1.9:1 at 2.5 h; cf. 1:1 in non-incubated cysts), and exocytosis of granules into the laminated layer adjacent to the cyst had occurred. This cannot be attributed wholly to serum proteins. Cysts incubated for 21 h appeared 'normal', suggesting re-establishment of an equilibrium. Since the matrix of the laminated layer is considered homologous to the glycocalyx of other cestodes, the possible protective role played by the granules/bodies, characteristic of Echinococcus spp., is discussed.

Ovine echinococcosis I. Immunological diagnosis by enzyme immunoassay.

PubMed

Gatti, Antonio; Alvarez, Angela Rosa; Araya, Daniel; Mancini, Sergio; Herrero, Eduardo; Santillan, Graciela; Larrieu, Edmundo

2007-01-31

Immunodiagnosis in sheep presents problems of sensitivity and specificity, limiting its applicability in surveillance systems. The objective of this study was to develop a sensitive, specific and accessible technique for diagnosing cystic echinococcosis in naturally infected sheep and to evaluate the validity of necropsy as a reference test. A total of 247 sheep were studied at slaughterhouses, confirming the parasitological diagnosis with histology. Serum was processed with enzyme immunoassay (EIA) using three antigen preparations: total hydatid liquid (LHT), purified fraction of LHT (S2B) and purified lipoprotein (B). Western Blot (WB) was used as a control. EIA proved effective for differentiating Echinococcus granulosus from larval stage of Taenia hydatigena and intestinal cestodes in all three antigen preparations. Serums from macroscopically negative sheep were reactive to EIA and positive with WB. In the whole flock, sensitivity was 89.2% for LHT, 80.0% for S2B and 86.4% for B. Sensitivity in lambs was 78.6% for LHT, 75.0% for S2B and 64.3% for B. Macroscopic diagnosis at the time of slaughter was found to have limitations as a reference test for immunodiagnosis of cystic equinococcosis in sheep, so it was necessary to include histology and WB as reference tests. LHT was the antigen preparation of greatest value and EIA proved to be a sensitive and specific technique, adequate for surveillance systems and for evaluating control programmes.

Taenia crassiceps upper limb fasciitis in a patient with untreated acquired immunodeficiency syndrome and chronic hepatitis C infection--the role of surgical debridement.

PubMed

Goesseringer, Nina; Lindenblatt, Nicole; Mihic-Probst, Daniela; Grimm, Felix; Giovanoli, Pietro

2011-07-01

We report a rare case of human Taenia crassiceps infection in a 47-year-old female patient with untreated acquired immunodeficiency syndrome and chronic hepatitis C infection. Little experience exists regarding the appropriate treatment of this infection. Usually, a combination of anthelmintic drugs is applied. Whether surgical measures are indicated have not been clarified. In our patient, initial surgery showed an abscess and fluid collection with numerous transparent cysts localised in the subcutaneous tissue of the cubital fossa. Parasitological and pathological examinations identified these structures as larvae of the cestode T. crassiceps. After treatment with anthelmintic medications, the patient was discharged in good condition. However, the patient presented with the clinical symptoms of an acute fasciitis of the right upper extremity 7 days later. The deteriorating general condition entailing a pre-septical state demanded emergency debridement and fasciectomy of the right arm. After the surgery, the patient recovered fully. Surgical treatment appears to be an important measure to reduce the tissue parasite load in patients with severe immunodeficiency. It also has to be questioned whether the bioavailability and the penetration of the drugs commonly administered is sufficiently high to treat such a fulminant infection alone. Copyright © 2011 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

First report of Taenia arctos (Cestoda: Taeniidae) from grizzly (Ursus arctos horribilis) and black bears (Ursus americanus) in North America.

PubMed

Catalano, Stefano; Lejeune, Manigandan; Verocai, Guilherme G; Duignan, Pádraig J

2014-04-01

The cestode Taenia arctos was found at necropsy in the small intestine of a grizzly (Ursus arctos horribilis) and a black bear (Ursus americanus) from Kananaskis Country in southwestern Alberta, Canada. The autolysis of the tapeworm specimens precluded detailed morphological characterization of the parasites but molecular analysis based on mitochondrial DNA cytochrome c oxidase subunit 1 gene confirmed their identity as T. arctos. This is the first report of T. arctos from definitive hosts in North America. Its detection in Canadian grizzly and black bears further supports the Holarctic distribution of this tapeworm species and its specificity for ursids as final hosts. Previously, T. arctos was unambiguously described at its adult stage in brown bears (Ursus arctos arctos) from Finland, and as larval stages in Eurasian elk (Alces alces) from Finland and moose (Alces americanus) from Alaska, USA. Given the morphological similarity between T. arctos and other Taenia species, the present study underlines the potential for misidentification of tapeworm taxa in previous parasitological reports from bears and moose across North America. The biogeographical history of both definitive and intermediate hosts in the Holarctic suggests an ancient interaction between U. arctos, Alces spp., and T. arctos, and a relatively recent host-switching event in U. americanus. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The genus Biuterina Fuhrmann, 1902 (Cestoda, Paruterinidae) in the Old World: redescriptions of three species from Palaearctic Passeriformes.

PubMed

Georgiev, Boyko B; Vasileva, Gergana P; Bray, Rodney A; Gibson, David I

2004-01-01

The syntypes of Biuterina passerina Fuhrmann, 1908 from Alauda arvensis and Galerida cristata (Passeriformes, Alaudidae) from an unknown locality are redescribed. B. fuhrmanni Schmelz, 1941 is redescribed on the basis of its syntypes from Emberiza aureola from China; its type-material contains, in addition to a scolex and pre-gravid and gravid fragments of Biuterina, fragments of mature proglottides from a dilepidid cestode, which were erroneously used in the original description. Specimens, which correspond morphologically to B. clerci Spasskii, 1946, from Miliaria calandra, E. citrinella and E. cirlus from Bulgaria and from E. citrinella from the Czech Republic, are studied. The synonymy of B. clerci with B. passerina is rejected; however, it is recognised as a synonym of B. fuhrmanni. Available data suggest that B. passerina is a specific parasite of birds of the family Alaudidae, while B. fuhrmanni is specific to the Emberizidae. B. collurionis Matevosyan, 1950 is considered a species inquirenda, pending confirmation of apparent differences from B. passerina and B. fuhrmanni based on further material. Biuterina cordifera Murai & Sulgostowska, 1983 is redescribed on the basis of specimens, previously identified by Rysavý (1965) as B. triangula (Krabbe, 1869), from Acrocephalus scirpaceus (Muscicapidae, Sylviinae) in the Czech Republic (new geographical record) and from Erithacus megarhynchos (Muscicapidae, Turdinae) in Bulgaria (new host and geographical records).

DNA Differential Diagnosis of Taeniasis and Cysticercosis by Multiplex PCR

PubMed Central

Yamasaki, Hiroshi; Allan, James C.; Sato, Marcello Otake; Nakao, Minoru; Sako, Yasuhito; Nakaya, Kazuhiro; Qiu, Dongchuan; Mamuti, Wulamu; Craig, Philip S.; Ito, Akira

2004-01-01

Multiplex PCR was established for differential diagnosis of taeniasis and cysticercosis, including their causative agents. For identification of the parasites, multiplex PCR with cytochrome c oxidase subunit 1 gene yielded evident differential products unique for Taenia saginata and Taenia asiatica and for American/African and Asian genotypes of Taenia solium with molecular sizes of 827, 269, 720, and 984 bp, respectively. In the PCR-based detection of tapeworm carriers using fecal samples, the diagnostic markers were detected from 7 of 14 and 4 of 9 T. solium carriers from Guatemala and Indonesia, respectively. Test sensitivity may have been reduced by the length of time (up to 12 years) that samples were stored and/or small sample volumes (ca. 30 to 50 mg). However, the diagnostic markers were detected by nested PCR in five worm carriers from Guatemalan cases that were found to be negative by multiplex PCR. It was noteworthy that a 720 bp-diagnostic marker was detected from a T. solium carrier who was egg-free, implying that it is possible to detect worm carriers and treat before mature gravid proglottids are discharged. In contrast to T. solium carriers, 827-bp markers were detected by multiplex PCR in all T. saginata carriers. The application of the multiplex PCR would be useful not only for surveillance of taeniasis and cysticercosis control but also for the molecular epidemiological survey of these cestode infections. PMID:14766815

Prevalence of Echinococcus granulosus taeniasis in stray dogs in the region of Constantine (North-East Algeria).

PubMed

Kohil, K; Benchikh El Fegoun, M C; Gharbi, M

2017-10-01

In North Africa, the domestic dog is regarded as the main reservoir for infection by Echinococcus granulosus of domestic livestock and man. In Algeria, there is very little data on the rate of infestation of dogs, while the prevalence of E. granulosus in the definitive host is a very reliable marker of the potential risk of transmission of cystic tapeworm to humans and livestock. To find out this information, a survey was conducted to assess the prevalence of infection with E. granulosus in stray dogs in the region of Constantine (North-East Algeria). We autopsied and examined 120 stray dogs, 22 (18.3%) of which were infected with E. granulosus, with an average intensity of infestation of 249 worms. The prevalence in the area of survey was evaluated: 15.5% (14/90) and 26.6% (8/30) dogs were parasitized by E. granulosus in urban and rural areas respectively. The influence of age on the rate of infection was very marked. In addition, the appreciation of the prevalence of parasitism by cestodes as a whole showed that 56 (46.6%) animals out of 120 were infected. Facing such a situation of endemic tapeworm parasitism, with a potential risk of transmission to humans, there is an urgent need to take measures to control and break the epidemiological cycles of the parasite.

Construction of In Vivo Fluorescent Imaging of Echinococcus granulosus in a Mouse Model.

PubMed

Wang, Sibo; Yang, Tao; Zhang, Xuyong; Xia, Jie; Guo, Jun; Wang, Xiaoyi; Hou, Jixue; Zhang, Hongwei; Chen, Xueling; Wu, Xiangwei

2016-06-01

Human hydatid disease (cystic echinococcosis, CE) is a chronic parasitic infection caused by the larval stage of the cestode Echinococcus granulosus. As the disease mainly affects the liver, approximately 70% of all identified CE cases are detected in this organ. Optical molecular imaging (OMI), a noninvasive imaging technique, has never been used in vivo with the specific molecular markers of CE. Thus, we aimed to construct an in vivo fluorescent imaging mouse model of CE to locate and quantify the presence of the parasites within the liver noninvasively. Drug-treated protoscolices were monitored after marking by JC-1 dye in in vitro and in vivo studies. This work describes for the first time the successful construction of an in vivo model of E. granulosus in a small living experimental animal to achieve dynamic monitoring and observation of multiple time points of the infection course. Using this model, we quantified and analyzed labeled protoscolices based on the intensities of their red and green fluorescence. Interestingly, the ratio of red to green fluorescence intensity not only revealed the location of protoscolices but also determined the viability of the parasites in vivo and in vivo tests. The noninvasive imaging model proposed in this work will be further studied for long-term detection and observation and may potentially be widely utilized in susceptibility testing and therapeutic effect evaluation.

Mechanistic insights into EgGST1, a Mu class glutathione S-transferase from the cestode parasite Echinococcus granulosus.

PubMed

Arbildi, Paula; Turell, Lucía; López, Verónica; Alvarez, Beatriz; Fernández, Verónica

2017-11-01

Glutathione transferases (GSTs) comprise a major detoxification system in helminth parasites, displaying both catalytic and non-catalytic activities. The kinetic mechanism of these enzymes is complex and depends on the isoenzyme which is being analyzed. Here, we characterized the kinetic mechanism of rEgGST1, a recombinant form of a cytosolic GST from Echinococcus granulosus (EgGST1), which is related to the Mu-class of mammalian enzymes, using the canonical substrates glutathione (GSH) and 1-chloro-2,4-dinitrobenzene (CDNB). Initial rate and product inhibition studies were consistent with a steady-state random sequential mechanism, where both substrates are bound to the enzyme before the products are released. Kinetic constants were also determined (pH 6.5 and 30 °C). Moreover, rEgGST1 lowered the pK a of GSH from 8.71 ± 0.07 to 6.77 ± 0.08, and enzyme-bound GSH reacted with CDNB 1 × 10 5 times faster than free GSH at pH 7.4. Finally, the dissociation of the enzyme-GSH complex was studied by means of intrinsic fluorescence, as well as that of the complex with the anthelminth drug mebendazole. This is the first report on mechanistic issues related to a helminth parasitic GST. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of Echinococcus granulosus on spleen cells and TGF-β expression in the peripheral blood of BALB/c mice.

PubMed

Yin, S; Chen, X; Zhang, J; Xu, F; Fang, H; Hou, J; Zhang, X; Wu, X; Chen, X

2017-03-01

Cystic echinococcosis (CE) caused by the cestode Echinococcus granulosus (E. granulosus) is a zoonotic parasitic disease. The effective immune evasion mechanisms of E. granulosus allow it to parasitize its hosts. However, the status of the innate and adaptive immune cells and their contributions to E. granulosus progression remain poorly understood. In this study, we aimed to determine the impact of E. granulosus infection on T cells, NK cell responses and TGF-β expression during the early infection phase in BALB/c mice. In E. granulosus infections, there was an increasing tendency in the percentage of CD4 + CD25 + T cells and CD4 + Foxp3 + T cells and peripheral blood TGF-β levels and relative expression of the Foxp3 gene. Moreover, there were a decreasing tendency in the percentage of NK cells and NK cell cytotoxicity and the expression of NKG2D on NK cells. The TGF-β1/Smad pathway was activated by E. granulosus in mice. Above results can be reversed by the inhibitor SB-525334 (potent activin receptor-like kinase 5 inhibitor). These results suggest that the TGF-β/Smad pathway plays an important role in changes of T-cell or NK cell responses. These results may contribute to revealing the preliminary molecular mechanisms in establishing hydatid infection. © 2017 John Wiley & Sons Ltd.

In Vitro and In Vivo Effects of Tamoxifen against Larval Stage Echinococcus granulosus

PubMed Central

Nicolao, María Celeste; Elissondo, María Celina; Denegri, Guillermo M.; Goya, Alejandra B.

2014-01-01

Cystic echinococcosis is a zoonotic infection caused by the larval stage of the cestode Echinococcus granulosus. Chemotherapy currently employs benzimidazoles; however, 40% of cases do not respond favorably. With regard to these difficulties, novel therapeutic tools are needed to optimize treatment in humans. The aim of this work was to explore the in vitro and in vivo effects of tamoxifen (TAM) against E. granulosus. In addition, possible mechanisms for the susceptibility of TAM are discussed in relation to calcium homeostasis, P-glycoprotein inhibition, and antagonist effects on a putative steroid receptor. After 24 h of treatment, TAM, at a low micromolar concentration range (10 to 50 μM), inhibited the survival of E. granulosus protoscoleces and metacestodes. Moreover, we demonstrated the chemotherapeutic and chemopreventive pharmacological effects of the drug. At a dose rate of 20 mg/kg of body weight, TAM induced protection against the infection in mice. In the clinical efficacy studies, a reduction in cyst weight was observed after the administration of 20 mg/kg in mice with cysts developed during 3 or 6 months, compared to that of those collected from control mice. Since the collateral effects of high TAM doses have been largely documented in clinical trials, the use of low doses of this drug as a short-term therapy may be a novel alternative approach for human cystic echinococcosis treatment. PMID:24936598

Short report: secondary transmission in porcine cysticercosis: description and their potential implications for control sustainability.

PubMed

Gonzalez, Armando E; López-Urbina, Teresa; Tsang, Byron Y; Gavidia, César M; Garcia, Héctor H; Silva, María E; Ramos, Daphne D; Manzanedo, Rafael; Sánchez-Hidalgo, Lelia; Gilman, Robert H; Tsang, Victor C W

2005-09-01

Taenia solium taeniasis/cysticercosis is one of few potentially eradicable infectious diseases and is the target of control programs in several countries. The larval stage of this zoonotic cestode invades the human brain and is responsible for most cases of adult-onset epilepsy in the world. The pig is the natural intermediate host, harboring the larvae or cysticerci. Our current understanding of the life cycle implicates humans as the only definitive host and tapeworm carrier (developing taeniasis) and thus the sole source of infective eggs that are responsible for cysticercosis in both human and pigs through oral-fecal transmission. Here we show evidence of an alternative pig-to-pig route of transmission, previously not suspected to exist. In a series of four experiments, naive sentinel pigs were exposed to pigs that had been infected orally with tapeworm segments (containing infective eggs) and moved to a clean environment. Consistently in all four experiments, at least one of the sentinel pigs became seropositive or infected with parasite cysts with much lower cyst burdens than did primarily infected animals. Second-hand transmission of Taenia solium eggs could explain the overdispersed pattern of porcine cysticercosis, with few pigs harboring heavy parasite burdens and many more harboring small numbers of parasites. This route of transmission opens new avenues for consideration with respect to control strategies.

Echinococcus multilocularis in Svalbard, Norway: microsatellite genotyping to investigate the origin of a highly focal contamination.

PubMed

Knapp, J; Staebler, S; Bart, J M; Stien, A; Yoccoz, N G; Drögemüller, C; Gottstein, B; Deplazes, P

2012-08-01

Echinococcus multilocularis is a threatening cestode involved in the human alveolar echinococcosis. The parasite, mainly described in temperate regions of the Northern hemisphere was described for the first time in 1999 in the High Arctic Svalbard archipelago, Norway. The origin of this contamination could be due to an anthropogenic introduction from mainland Europe by domestic dogs or with the introduction of the sibling vole, perhaps from mainland Russia (St. Petersburg area), or with roaming Arctic foxes, known as the main definitive host of the parasite in Arctic regions. The genetic diversity of E. multilocularis in Svalbard was investigated here for the first time by genotyping using EmsB microsatellite and compared to other genotyped populations in the main worldwide endemic areas. We found low polymorphism amongst the 27 metacestode isolates from sibling voles trapped in the core of the distribution area of the vole on Svalbard. E. mutilocularis Arctic populations, using the Arctic fox as the definitive host, were genetically separated from European temperate populations that use the red fox, but closely related to St. Lawrence Island samples from Alaska. The result is inconsistent with the hypothesis of an anthropogenic introduction from mainland Europe, but can be seen as consistent with the hypothesis that Arctic foxes introduced E. multilocularis to Svalbard. Copyright © 2012 Elsevier B.V. All rights reserved.

[Prokaryotic expression and histological localization of the Taenia solium CDC37 gene].

PubMed

Huang, Jiang; Li, Bo; Dai, Jia-Lin; Zhang, Ai-Hua

2013-02-01

To express Taenia solium gene encoding cell division cycle 37 protein (TsCDC37) and investigate its antigenicity and localization in adults of Taenia solium. The complete coding sequence of TsCDC37 was amplified by PCR based on the recombinant plasmid clone from the cDNA library of adult Taenia solium. The PCR product was cloned into a prokaryotic expression vector pET-28a (+). The recombinant expression plasmid was identified by PCR, double endonuclease digestion and sequencing. The recombinant plasmid was transformed into E. coli BL21/DE3 and followed by expression of the protein induced by IPTG. The mice were immunized subcutaneously with purified recombinant TsCDC37 formulated in Freund's adjuvant. The antigenicity of the recombinant protein was examined by Western blotting. The localization of TsCDC37 in adult worms was demonstrated by immunofluorescent technique. The recombinant expression vector was constructed successfully. The recombinant protein was about M(r) 52 000, it was then purified and specifically recognized by immuno sera of SD rats and sera from patients infected with Taenia solium, Taenia saginata or Taenia asiatica. The immunofluorescence assay revealed that TsCDC37 located at the tegument of T. solium adult and the eggs. TsCDC37 gene has been expressed with immunoreactivity. The recombinant protein is mainly expressed in tegument and egg, and is a common antigen of the three human taenia cestodes.

Helminth Infections of Stray Dogs from Garmsar, Semnan Province, Central Iran

PubMed Central

Eslami, A; Ranjbar-Bahadori, Sh; Meshgi, B; Dehghan, M; Bokaie, S

2010-01-01

Background The aim was to study the gastro-intestinal helminths of stray dogs of Garmsar, Semnan Province, Central Iran, and its impacts on human health and animal production. Methods During 2006, the alimentary tracts of 50 stray dogs at necropsy, selected from villages around Garmsar, were removed, and examined for helminth infections. Subsequently helminths were collected from the contents of each part and scraped sample of small intestines of washed materials in a 100-mesh sieve. To identify the species of helminths, the nematodes were cleared in lactophenol and cestodes were stained using carmine acid. Results Mixed infection was the rule and 40 dogs (80%) harbored more than one species of helminth. Taenia hydatigena was the most prevalent species (80%) followed by Echinococcus granulosus (64%), Toxocara canis (22%), Mesocestoides lineatus (12%), Taenia multiceps (10%) and Dipylidium caninum (4%). The mean intensity of worm infection was low (1–3) except for that of E. granulosus (645). No significant difference was noticed between sex, age and most helminth infections except for that of sex and T. hydatigena (P=0.001) as well as age and T. canis (P=0.001). Conclusion Although human infection with T. hydatigena is unlikely, but other helminths reported in this study are of zoonotic importance, and may pose a threat to community health, and reduce the productions of ruminants harboring taeniid metacestodes. PMID:22347264

Zoonotic and human parasites of inhabitants of Cueva de los Muertos Chiquitos, Rio Zape Valley, Durango, Mexico.

PubMed

Jiménez, F Agustín; Gardner, Scott L; Araújo, Adauto; Fugassa, Martín; Brooks, Richard H; Racz, Elizabeth; Reinhard, Karl J

2012-04-01

We present the first reconstruction of the parasitoses among the people of the Loma San Gabriel culture, as represented by 36 coprolites excavated from the Cueva de los Muertos Chiquitos in Durango, Mexico. The coprolites date to approximately 1,400-yr-ago. Species identified based on eggs recovered include the trematode Echinostoma sp., the tapeworms Hymenolepis sp. and Dipylidium caninum , and the nematodes Ancylostoma duodenale, Enterobius vermicularis, and Trichuris trichiura. After rehydration and screening, 2 methods were used to recover eggs from these samples including spontaneous sedimentation and flotation. Samples were analyzed by 3 different laboratories for independent verification and comparison of methods. Spontaneous sedimentation resulted in the discovery of hymenolepidid eggs that were not found with flotation. Sedimentation was a more-sensitive indicator of prevalence as well. The modified method of flotation permitted estimation of egg concentration and resulted in the detection of a few specimens not found by sedimentation. The results of both methods showed that 19 (of 36) coprolites contained helminth eggs. Our results detected the presence of pathogenic helminths including hookworms and whipworms. The cestodes found do not cause severe pathology in humans. The early dates of hookworm and whipworm, relative to other findings in the southwest United States, indicate that these parasites arrived relatively late in prehistory in Arizona and New Mexico, probably moving into the area with travelers from Mesoamerica.

Paralogues of nuclear ribosomal genes conceal phylogenetic signals within the invasive Asian fish tapeworm lineage: evidence from next generation sequencing data.

PubMed

Brabec, Jan; Kuchta, Roman; Scholz, Tomáš; Littlewood, D Timothy J

2016-08-01

Complete mitochondrial genomes and nuclear rRNA operons of eight geographically distinct isolates of the Asian fish tapeworm Schyzocotyle acheilognathi (syn. Bothriocephalus acheilognathi), representing the parasite's global diversity spanning four continents, were fully characterised using an Illumina sequencing platform. This cestode species represents an extreme example of a highly invasive, globally distributed pathogen of veterinary importance with exceptionally low host specificity unseen elsewhere within the parasitic flatworms. In addition to eight specimens of S. acheilognathi, we fully characterised its closest known relative and the only congeneric species, Schyzocotyle nayarensis, from cyprinids in the Indian subcontinent. Since previous nucleotide sequence data on the Asian fish tapeworm were restricted to a single molecular locus of questionable phylogenetic utility-the nuclear rRNA genes-separating internal transcribed spacers-the mitogenomic data presented here offer a unique opportunity to gain the first detailed insights into both the intraspecific phylogenetic relationships and population genetic structure of the parasite, providing key baseline information for future research in the field. Additionally, we identify a previously unnoticed source of error and demonstrate the limited utility of the nuclear rRNA sequences, including the internal transcribed spacers that has likely misled most of the previous molecular phylogenetic and population genetic estimates on the Asian fish tapeworm. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Cavearhynchus, a new genus of tapeworm (Cestoda: Trypanorhyncha: Pterobothriidae) from Himantura lobistoma Manjaji-Matsumoto & Last, 2006 (Rajiformes) off Borneo, including redescriptions and new records of species of Pterobothrium Diesing, 1850.

PubMed

Schaeffner, Bjoern C; Beveridge, Ian

2012-06-01

A new genus of trypanorhynch cestode is described from the tubemouth whipray Himantura lobistoma Manjaji-Matsumoto & Last, 2006 in the South China Sea off Malaysian Borneo. Cavearhynchus foveatus n. g., n. sp. possesses four pedicellate bothria in a cruciform arrangement, a heteroacanthous, heteromorphous metabasal tentacular armature with five hooks per principle row and an alternating longitudinal file of intercalary hooks on the bothrial surface of each tentacle, but lacks prebulbar organs and gland-cells within the bulbs. It, thus, closely resembles taxa belonging to the lacistorhynchoid family Pterobothriidae Pintner, 1931. However, the new genus differs from other genera within this family in the possession of bothrial pits. Although a distinguishing characteristic of the superfamily Otobothrioidea Dollfus, 1942, representatives of this group exhibit two bothria and the bothrial pits are lined with spiniform microtriches, whereas the pit-like structures.of C. foveatus n. g., n. sp. entirely lack microtriches. Redescriptions of two species of Pterobothrium, namely P. lesteri Campbell & Beveridge, 1996 and P. platycephalum (Shipley & Hornell, 1906) Dollfus, 1930 are provided from material collected off Borneo and several localities off Australia. Moreover, new host and locality records are added for P. australiense Campbell & Beveridge, 1996 and P. pearsoni (Southwell, 1929) Beveridge & Campbell, 1989.

Anticestodal activity of Houttuynia cordata leaf extract against Hymenolepis diminuta in experimentally infected rats.

PubMed

Yadav, Arun K; Temjenmongla

2011-10-01

The leaves of Houttuynia cordata Thunb. (Saururaceae) are considered to have anthelmintic properties in the traditional medicine of Naga tribes in Northeast India and, therefore, are used by the natives to treat the intestinal worm infections. In the present study, the anticestodal activity of H. cordata leaf extract was investigated against Hymenolepis diminuta, a zoonotic cestode, in experimentally infected albino rats. For the assessment of anticestodal efficacy, the eggs per gram (EPG) of faeces counts and worm loads of animals were monitored following treatment with 200, 400 and 800 mg/kg p.o. doses of leaf extract to different groups of rats harbouring larval, immature and mature H. diminuta infections. The efficacy of the extract was found to be dose-dependent (P < 0.05). Further, the extract showed its maximum efficacy against the mature Hymenolepis worms. In this case, the 800 mg/kg dose of extract significantly reduced (P < 0.001) the EPG counts of animals by 57.09% and worm load by 75.00%, at post-treatment. In comparison, the reference drug praziquantel at 5 mg/kg showed a reduction in the EPG counts and worm load of experimental animals by 80.37 and 87.50%, respectively. These findings indicate that leaves of H. cordata possess significant anticestodal property and provide a rationale for their use in traditional medicine as an anthelmintic.

Gold nanoparticles - against parasites and insect vectors.

PubMed

Benelli, Giovanni

2018-02-01

Nanomaterials are currently considered for many biological, biomedical and environmental purposes, due to their outstanding physical and chemical properties. The synthesis of gold nanoparticles (Au NPs) is of high interest for research in parasitology and entomology, since these nanomaterials showed promising applications, ranging from detection techniques to drug development, against a rather wide range of parasites of public health relevance, as well as on insect vectors. Here, I reviewed current knowledge about the bioactivity of Au NPs on selected insect species of public health relevance, including major mosquito vectors, such as Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. The toxicity of Au NPs against helminths was reviewed, covering Schistosoma mansoni trematodes as well as Raillietina cestodes. Furthermore, I summarized the information available on the antiparasitic role of Au NPs in the fight against malaria, leishmaniosis, toxoplasmosis, trypanosomiasis, cryptosporidiosis, and microsporidian parasites affecting human and animals health. Besides, I examined the employ of Au NPs as biomarkers, tools for diagnostics and adjuvants for the induction of transmission blocking immunity in malaria vaccine research. In the final section, major challenges and future outlooks for further research are discussed, with special reference to the pressing need of further knowledge about the effect of Au NPs on other arthropod vectors, such as ticks, tsetse flies, tabanids, sandflies and blackflies, and related ecotoxicology assays. Copyright © 2017 Elsevier B.V. All rights reserved.

The Effect of Anthelmintic Treatment on Coccidia Oocyst Shedding in a Wild Mammal Host with Intermittent Cestode Infection

PubMed Central

Václav, Radovan; Blažeková, Jana

2014-01-01

While hosts are routinely exploited by a community of parasite species, the principles governing host responses towards parasites are unclear. Identifying the health outcomes of coinfections involving helminth macroparasites and microparasites is one area of importance for public and domestic animal health. For instance, it is controversial how deworming programmes affect incidence and severity of such important microparasite diseases as malaria. One problem is that most study systems involve domestic and laboratory animals with conditions hardly comparable to those of free-living animals. Here, we study the effect of anthelmintic treatment on coccidia infection intensity in wild Alpine marmots, M. marmota. Our results lend support to the hypothesis that helminth infection has a positive effect on concurrent microparasite infection. However, our work also points to the fact that within-host interactions between helminths and microparasites are context-dependent and can turn to negative ones once helminth burdens increase. Our study suggests that coccidia benefit from intermittent helminth infection in marmots due to the protective effects of helminth infection only during the early phase of the host's active season. Also, the marmot's response towards coccidia infection appears optimal only under no helminth infection when the host immune response towards coccidia would not be compromised, thereby pointing to the importance of regular intestinal helminth elimination by marmots just before hibernation. PMID:25506065

The effect of anthelmintic treatment on coccidia oocyst shedding in a wild mammal host with intermittent cestode infection.

PubMed

Václav, Radovan; Blažeková, Jana

2014-01-01

While hosts are routinely exploited by a community of parasite species, the principles governing host responses towards parasites are unclear. Identifying the health outcomes of coinfections involving helminth macroparasites and microparasites is one area of importance for public and domestic animal health. For instance, it is controversial how deworming programmes affect incidence and severity of such important microparasite diseases as malaria. One problem is that most study systems involve domestic and laboratory animals with conditions hardly comparable to those of free-living animals. Here, we study the effect of anthelmintic treatment on coccidia infection intensity in wild Alpine marmots, M. marmota. Our results lend support to the hypothesis that helminth infection has a positive effect on concurrent microparasite infection. However, our work also points to the fact that within-host interactions between helminths and microparasites are context-dependent and can turn to negative ones once helminth burdens increase. Our study suggests that coccidia benefit from intermittent helminth infection in marmots due to the protective effects of helminth infection only during the early phase of the host's active season. Also, the marmot's response towards coccidia infection appears optimal only under no helminth infection when the host immune response towards coccidia would not be compromised, thereby pointing to the importance of regular intestinal helminth elimination by marmots just before hibernation.

The immune response to parasitic helminths of veterinary importance and its potential manipulation for future vaccine control strategies.

PubMed

Foster, Neil; Elsheikha, Hany M

2012-05-01

Despite the increasing knowledge of the immunobiology and epidemiology of parasitic helminths of the gastrointestinal system and the cardiorespiratory system, complications arising from infections of animals and humans with these parasites are a major clinical and economic problem. This has been attributed to the high incidence of these parasites, the widespread emergence of multi-drug resistant parasite strains and the lack of effective vaccines. Efforts to develop and produce vaccines against virtually all helminths (with the exception of Dictyocaulus viviparus and some cestode species) have been hindered by the complexity of the host-parasite relationship, and incomplete understanding of the molecular and immune regulatory pathways associated with the development of protective immunity against helminths. Novel genomic and proteomic technologies have provided opportunities for the discovery and characterisation of effector mechanisms and molecules that govern the host-parasite interactions in these two body systems. Such knowledge provided clues on how appropriate and protective responses are elicited against helminths and, thus, may lead to the development of effective therapeutic strategies. Here, we review advances in the immune response to selected helminths of animal health significance, and subsequent vaccine potential. The topics addressed are important for understanding how helminths interact with host immune defences and also are relevant for understanding the pathogenesis of diseases caused by helminths.

Genome mining offers a new starting point for parasitology research.

PubMed

Lv, Zhiyue; Wu, Zhongdao; Zhang, Limei; Ji, Pengyu; Cai, Yifeng; Luo, Shiqi; Wang, Hongxi; Li, Hao

2015-02-01

Parasites including helminthes, protozoa, and medical arthropod vectors are a major cause of global infectious diseases, affecting one-sixth of the world's population, which are responsible for enormous levels of morbidity and mortality important and remain impediments to economic development especially in tropical countries. Prevalent drug resistance, lack of highly effective and practical vaccines, as well as specific and sensitive diagnostic markers are proving to be challenging problems in parasitic disease control in most parts of the world. The impressive progress recently made in genome-wide analysis of parasites of medical importance, including trematodes of Clonorchis sinensis, Opisthorchis viverrini, Schistosoma haematobium, S. japonicum, and S. mansoni; nematodes of Brugia malayi, Loa loa, Necator americanus, Trichinella spiralis, and Trichuris suis; cestodes of Echinococcus granulosus, E. multilocularis, and Taenia solium; protozoa of Babesia bovis, B. microti, Cryptosporidium hominis, Eimeria falciformis, E. histolytica, Giardia intestinalis, Leishmania braziliensis, L. donovani, L. major, Plasmodium falciparum, P. vivax, Trichomonas vaginalis, Trypanosoma brucei and T. cruzi; and medical arthropod vectors of Aedes aegypti, Anopheles darlingi, A. sinensis, and Culex quinquefasciatus, have been systematically covered in this review for a comprehensive understanding of the genetic information contained in nuclear, mitochondrial, kinetoplast, plastid, or endosymbiotic bacterial genomes of parasites, further valuable insight into parasite-host interactions and development of promising novel drug and vaccine candidates and preferable diagnostic tools, thereby underpinning the prevention and control of parasitic diseases.

Parasitic infection by larval helminths in Antarctic fishes: pathological changes and impact on the host body condition index.

PubMed

Santoro, Mario; Mattiucci, Simonetta; Work, Thierry; Cimmaruta, Roberta; Nardi, Valentina; Cipriani, Paolo; Bellisario, Bruno; Nascetti, Giuseppe

2013-07-22

We examined pathological changes and relationship between body condition index (BCI) and parasitic infection in 5 species of fish, including 42 icefish Chionodraco hamatus (Channichtyidae), 2 dragonfish Cygnodraco mawsoni (Bathydraconidae), 30 emerald rock cod Trematomus bernacchii, 46 striped rock cod T. hansoni and 9 dusty rock cod T. newnesi (Nototheniidae) from the Ross Sea, Antarctica. All parasites were identified by a combination of morphology and mtDNA cytochrome-oxidase-2 sequence (mtDNA cox2) analysis, except Contracaecum osculatum s.l., for which only the latter was used. Five larval taxa were associated with pathological changes including 2 sibling species (D and E) of the C. osculatum species complex and 3 cestodes including plerocercoids of a diphyllobothridean, and 2 tetraphyllidean forms including cercoids with monolocular and bilocular bothridia. The most heavily infected hosts were C. hamatus and C. mawsoni, with C. hamatus most often infected by C. osculatum sp. D and sp. E and diphyllobothrideans, while C. mawsoni was most often infected with tetraphyllidean forms. Histologically, all fish showed varying severity of chronic inflammation associated with larval forms of helminths. Diphyllobothrideans and C. osculatum spp. were located in gastric muscularis or liver and were associated with necrosis and mild to marked fibrosis. Moderate multifocal rectal mucosal chronic inflammation was associated with attached tetraphyllidean scolices. C. hamatus showed a strong negative correlation between BCI and parasite burden.

Parasitic helminths: a pharmacopeia of anti-inflammatory molecules.

PubMed

Johnston, M J G; MacDonald, J A; McKay, D M

2009-02-01

Infection with parasitic helminths takes a heavy toll on the health and well-being of humans and their domestic livestock, concomitantly resulting in major economic losses. Analyses have consistently revealed bioactive molecules in extracts of helminths or in their excretory/secretory products that modulate the immune response of the host. It is our view that parasitic helminths are an untapped source of immunomodulatory substances that, in pure form, could become new drugs (or models for drug design) to treat disease. Here, we illustrate the range of immunomodulatory molecules in selected parasitic trematodes, cestodes and nematodes, their impact on the immune cells in the host and how the host may recognize these molecules. There are many examples of the partial characterization of helminth-derived immunomodulatory molecules, but these have not yet translated into new drugs, reflecting the difficulty of isolating and fully characterizing proteins, glycoproteins and lipid-based molecules from small amounts of parasite material. However, this should not deter the investigator, since analytical techniques are now being used to accrue considerable structural information on parasite-derived molecules, even when only minute quantities of tissue are available. With the introduction of methodologies to purify and structurally-characterize molecules from small amounts of tissue and the application of high throughput immunological assays, one would predict that an assessment of parasitic helminths will yield a variety of novel drug candidates in the coming years.

Diversity of helminth parasites in aquatic invertebrate hosts in Latin America: how much do we know?

PubMed

Aguirre-Macedo, M L; May-Tec, A L; Martínez-Aquino, A; Cremonte, F; Martorelli, S R

2017-03-01

Helminths in aquatic invertebrate hosts have been overlooked in comparison with vertebrate hosts. Therefore, the known diversity, ecology and distribution of these host-parasite systems are very limited in terms of their taxonomic diversity, habitat and geographic regions. In this study we examined the published literature on helminth parasites of aquatic invertebrates from Latin America and the Caribbean (LAC) to identify the state of the knowledge in the region and to identify patterns of helminth diversity. Results showed that 67% of the literature is from Argentina, Mexico and Brazil. We found records for 772 host-parasite associations. Most records relate to medically or economically important hosts. Molluscs were the most studied host group with 377 helminth records (80% trematodes). The lymnaeids and planorbids were the most studied molluscs across LAC. Arthropods were the second most studied host group with 78 helminth records (trematodes 38%, cestodes 24% and nematodes 20%), with shrimps and crabs being the most studied hosts. Host species with the largest number of helminth taxa were those with a larger sampling effort through time, usually in a small country region. No large geographical-scale studies were identified. In general, the knowledge is still too scarce to allow any zoogeographical or helminth diversity generalization, as most hosts have been studied locally and the studies on invertebrate hosts in LAC are substantially uneven among countries.

Gastrointestinal helminths of camels (Camelus dromedarius) in center of Iran.

PubMed

Anvari-Tafti, M; Sazmand, A; Hekmatimoghaddam, S; Moobedi, I

2013-03-01

Camels are multipurpose animals in Iran. As parasitic diseases are the major cause of impaired meat and milk production in this animal, the present study aimed at determining gastrointestinal helminthic infections of Iranian camels in the center of the country. Gastrointestinal (GI) tract of 144 carcasses of one-humped camels (Camelus dromedarius) slaughtered in Yazd, Esfahan and Kerman provinces' abattoirs were examined for adult helminths. Camels were from both sexes and different ages. Recovered parasites were identified according to described keys by light microscope. Of 144 tested camels, 117 were infected with at least one helminth species (81.3%). A total of 28 worm species from 14 genera were identified in the digestive tract of infected animals, including 26 species of nematodes and two species of cestodes. The infection rates in stomach, small intestine, and caecum/large intestine were 86.3%, 91.5% and 11.1%, respectively. However, no worm was found in the oesophagus. The recovered worms with infection rates are discussed in this paper. In the present study, Haemonchus tataricus, Trichostrongylus hamatus and Trichuris infundibulus are reported from Iranian dromedaries for the first time. Regarding high prevalence of infection, using anthelminthic drugs seemed necessary to improve the health and productivity of camels. On the other hand, the high rate of zoonotic species indicated that camels have important role in maintaining and transmitting infection to humans.

Helminth communities of two populations of Myotis chiloensis (Chiroptera: Vespertilionidae) from Argentinean Patagonia.

PubMed

Falconaro, Antonella C; Vega, Rocío M; Viozzi, Gustavo P

2018-04-01

Most of the studies on chiropteran endoparasites in Argentina come from the Central and Northeast regions of the country, and there is only one parasitological study of bats from the Argentinean Patagonia. The aim of this study is to describe the helminth fauna of 42 Myotis chiloensis, comparing the composition and the structure of the endoparasite communities between two populations, inhabiting different environments in Andean humid forest and the ecotone between forest and Patagonian steppe. A total of 697 helminths were recovered from 33 bats: five species of trematodes, Ochoterenatrema sp., Paralecithodendrium sp., Parabascus limatulus , Parabascus sp., and Postorchigenes cf. joannae , two species of cestodes, Vampirolepis sp. 1 and Vampirolepis sp. 2, and three species of nematodes, Allintoshius baudi , Physaloptera sp., and Physocephalus sp. All the helminths, but Physocephalus sp., were recovered from the small and large intestine. This is the first survey of M. chiloensis ' helminth fauna. All the species, but A. baudi , represent new records of helminths in Patagonian bats. There were differences of parasite species richness between localities and both bat populations share almost half of the endoparasite species. Different preferences for intestinal regions were found for three species of trematodes in the bats from the site in the humid forest. Myotis chiloensis serves as both a definitive and intermediate host for endoparasites in the Patagonian ecosystem.

Host specificity and the structure of helminth parasite communities of fishes in a Neotropical river in Mexico.

PubMed

Salgado-Maldonado, Guillermo; Novelo-Turcotte, María Teresa; Caspeta-Mandujano, Juan Manuel; Vazquez-Hurtado, Gabriela; Quiroz-Martínez, Benjamin; Mercado-Silva, Norman; Favila, Mario

2016-01-01

In a tropical locality of Río La Antigua, Veracruz, Mexico, 11 fish species, represented by 244 individual fish from six freshwater fish families living sympatrically and synchronically, were examined for helminth parasites. A total of 36 taxa of helminths were recorded, 24 autogenic and 12 allogenic forms, including 6 monogeneans, 14 trematodes, 1 cestode, and 15 nematodes. Most helminth taxa were recovered for 10/11 of the component communities we analyzed. The results contribute empirical evidence that host specificity is an important force in the development of helminth communities of freshwater fishes. Each fish family has their own set of parasites, host species belonging to the same taxon share parasite species. High component community similarity among related host species was recorded, demonstrated by high prevalence and abundance, as well as dominance, of autogenic specialist species in each component community. Most autogenic helminth species are numerically and reproductively successful in relatively few host species. Autogenic helminths common in one host species are not common in others. Our findings give empirical support to the idea that low levels of sharing of parasites favor animal coexistence and high species richness, because large phylogenetic differences allow potentially competing animals to consume the same resources without being sensitive of another's parasites. © G. Salgado-Maldonado et al., published by EDP Sciences, 2016.

Ecology of the parasitic endohelminth community of Pseudoplatystoma fasciatum (Linnaeus, 1776) (Siluriformes: Pimelodidae) from the Aquidauana River, Pantanal, State of Mato Grosso do Sul, Brazil.

PubMed

Campos, C M; Fonseca, V E; Takemoto, R M; Moraes, F R

2009-02-01

This study investigated the structure and diversity of the endohelminth community and its interactions with Pseudoplatystoma fasciatum, caught in the Aquidauana River, in the State of Mato Grosso do Sul, Brazil. Ten helminth species were represented in 1,228 specimens of parasites found in the intestine and mesentery of 33 specimens of P. fasciatum. Cestodes were observed in the intestine, while nematodes Cucullanus sp. in the mesentery. Contracaecum sp. Type 1, Spatulifer rugosa and Choanoscolex abscisus showed the highest mean intensity and mean abundance and Nomimoscolex sudobin showed the highest prevalence. Simpson's index indicated dominance in the endohelminth infracommunities (C = 1.0792) and Choanoscolex abscisus was considered the central species. A clumped pattern of dispersion according to Green's index was related. 69.69% of hosts analyzed had between 2 and 5 species of endohelminths. Mean diversity was H = 0.5517 (SD = 0.4209). Two pairs of species showed significant positive association and four pairs presented significant positive correlation among abundance data. Significant negative correlations between total length and prevalence and abundance of Peltydocotyle rugosa and Nomimoscolex sudobim were found. However, no significant correlation was observed between condition factor and abundance, as well as total length and diversity. There was significant prevalence of Harriscolex kaparari in male hosts.

Endoparasitic fauna of red foxes (Vulpes vulpes) and golden jackals (Canis aureus) in Serbia.

PubMed

Ilić, Tamara; Becskei, Zsolt; Petrović, Tamaš; Polaček, Vladimir; Ristić, Bojan; Milić, Siniša; Stepanović, Predrag; Radisavljević, Katarina; Dimitrijević, Sanda

2016-03-01

Wild canides have a high epizootiological - epidemiological significance, considering that they are hosts for some parasites which spread vector born diseases. Increased frequency of certain interactions between domestic and wild canides increases the risk of occurrence, spreading and maintaining the infection of parasitic etiology in domestic canides. The research was conducted in 232 wild canides (172 red foxes and 60 golden jackals). The examined material was sampled from foxes and jackals, which were hunted down between 2010 and 2014, from 8 epizootiological areas of Serbia (North-Bačka, West-Bačka, Southern-Banat, Moravički, Zlatiborski, Raški, Rasinski and Zaječarski district). On completing the parasitological dissection and the coprological diagnostics, in wild canides protozoa from the genus Isospora were identified, 3 species of trematoda (Alaria alata, Pseudamphistomum truncatum and Metagonimus yokogawai), cestods from the genus Taenia and 5 species of nematodes (Toxocara canis, Ancylostomatidae, Trichuris vulpis and Capillaria aerophila). The finding of M. yokogawai in golden jackals were, to the best of our knowledge, one of the first diagnosed cases of metagonimosis in golden jackals in Serbia. The continued monitoring of the parasitic fauna of wild canides is needed to establish the widespread of the zoonoses in different regions of Serbia, because they present the reservoirs and/or sources of these infections.

Infection patterns of Nile tilapia (Oreochromis niloticus L.) by two helminth species with contrasting life styles.

PubMed

Akoll, Peter; Konecny, Robert; Mwanja, Wilson W; Schiemer, Fritz

2012-04-01

The larval stages of Bolbophorus sp. (digenean) and Amirthalingamia macracantha (cestode) are frequently reported in Oreochromis niloticus in Uganda. Little, however, is known about their infection patterns. This study examined the influence of habitat type, host size, and sex and weather patterns on the parasite populations in Uganda. A total of 650 fish were collected between January and November 2008 from a reservoir, cages, fishponds and a stream. The prevalence and intensity of A. macracantha and the prevalence of Bolbophorus sp. differed across the water bodies reflecting the effect of habitat characteristics on parasite transmission. Host sex did not significantly influence the infection patterns, although female fish were slightly more parasitized than male and sexually undifferentiated individuals. The fish size was positively correlated with helminth infections demonstrating accumulation and prolonged exposure of larger (older) fish to the parasites. The metacercariae population did not vary significantly across months, while monthly A. macracantha infection fluctuated markedly. With regard to rain seasons, higher prevalence and intensity of A. macracantha were recorded in wet season. For Bolbophorus sp., only the prevalence varied with seasons, with higher prevalence recorded in the dry season than in wet season. Generally, Bolbophorus sp. responded weakly to changes in water body, host sex and size and weather patterns. Rainfall appears to be an essential cue for coracidia hatching.

Intestinal helminths of a landlocked ringed seal (Phoca hispida saimensis) population in eastern Finland.

PubMed

Sinisalo, Tuula; Kunnasranta, Mervi; Valtonen, E Tellervo

2003-09-01

A small, landlocked, endangered ringed seal (Phoca hispida saimensis) population lives as a postglacial relict in Lake Saimaa in eastern Finland. In this study, the intestinal metazoans were examined from a total of 61 Saimaa seals found dead from 1981 to 2001. The helminth fauna was very depauperate. Only one acanthocephalan species, Corynosoma magdaleni, has been able to survive during isolation in the freshwater environment. In addition, only two cestode species were found: Diphyllobothrium ditretum and Schistocephalus sp. However, neither of these larvae developed in the ringed seals. As the newborn pups of Saimaa seals are nursed for about 2 months only one of them was infected by C. magdaleni. At 2-5 months the pups harboured worms; however, the mean intensity did not rise distinctively until the seals were adults. C. magdaleni infection increased with increasing age and the abundances were significantly different between the age groups. There was no correlation between the number of parasites and the adult seal body weight; however, seals weighing 36 kg or more carried the majority of the worms. The distribution of the parasites was aggregated; six seals carried 65% (n=1,182) of all worms (total n=1,809) and 26 seals were uninfected. Variation in the number of worms in individual seals may indicate differences in feeding behaviour and in the diet of seals, and/or variation in the immune status of the seals.

Taxonomy, distribution and prevalence of parasites of tigerfish, Hydrocynus vittatus (Castelnau, 1861) in the Sanyati basin, Lake Kariba, Zimbabwe.

PubMed

Mabika, Nyasha; Barson, Maxwell; Van Dyk, Cobus; Avenant-Oldewage, Annemariè

2016-09-01

Parasites of the tigerfish (Hydrocynus vittatus) were investigated in the period October 2014 to July 2015 in the Sanyati Basin, Lake Kariba. The fish were collected using seine netting and also during the annual Kariba International Tiger Fishing Tournament. A total of 80 fish specimens (24 males and 56 females) were collected and were infected with the following seven parasite taxa: Monogenea (Annulotrema sp.1 from the gills and Annulotrema sp.2 from the skin), Nematoda (Contracaecum larvae), Cestoda (bothriocephalid, larval cyclophyllid), Copepoda (Lamproglena hemprichii), pentastomid, Myxosporea (Myxobolus sp.,) and unicellular ciliate parasites (Trichodina sp., Tetrahymena sp., and unidentified). Annulotrema sp. 1 was observed in all fish and had the highest prevalence, mean intensity and abundance. The fish organs infected were gills, skin, fin, body cavity, stomach, intestines, mesentery, liver, kidney, brain cavity and swim bladder. No parasites were observed in the muscle, eyes and blood. The distribution of the parasites was highest in the gills and lowest in the brain cavity and swimbladder. Bothriocephalids, pentastomes and Trichodina sp. were not observed in male fish. Sex was not related to the intensity of parasites. The results of the study showed that H. vittatus has a richer parasite community than other previous investigated alestids. Pentastomes, Myxobolus sp., Trichodina sp., Tetrahymena sp. and bothriocephalid cestodes are new records for H. vittatus in Zimbabwe.

Canine echinococcosis: global epidemiology and genotypic diversity.

PubMed

Carmena, David; Cardona, Guillermo A

2013-12-01

Canine echinococcosis is a potential zoonotic infection caused by the adult form of several cestode species belonging to the genus Echinococcus, of which E. granulosus sensu lato and E. multilocularis are the most epidemiologically relevant. Dogs infected with E. granulosus and E. multilocularis are widely regarded as the main source of infection for human cystic and alveolar echinococcosis, diseases that cause substantial morbidity and socio-economic burden in several regions of the world. Following our previous review on the global situation of cystic echinococcosis in livestock species (Cardona and Carmena. Vet. Parasitol. 2013;192:10-32), we summarize here current knowledge on the global epidemiology, geographical distribution and molecular diversity of Echinococcus spp. infection in dogs. We address relevant topics including the implications of the increasing urbanization of wildlife species such as foxes, coyotes, and dingoes in the establishment of urban cycles of Echinococcus spp., or the rising concerns regarding the role of unsupervised translocation of infected dogs in spreading the infection to Echinococcus-free areas. The involvement of wildlife species as natural reservoirs of disease to domestic animals and humans and the epidemiological significance of the sympatric occurrence of different Echinococcus species in the same geographical region are also debated. Data presented are expected to be useful for policy makers, educational and health authorities responsible for designing and implementing effective measures for disease control and prevention. Copyright © 2013 Elsevier B.V. All rights reserved.

Pathological and Ecological Host Consequences of Infection by an Introduced Fish Parasite

PubMed Central

Britton, J. Robert; Pegg, Josephine; Williams, Chris F.

2011-01-01

The infection consequences of the introduced cestode fish parasite Bothriocephalus acheilognathi were studied in a cohort of wild, young-of-the-year common carp Cyprinus carpio that lacked co-evolution with the parasite. Within the cohort, parasite prevalence was 42% and parasite burdens were up to 12% body weight. Pathological changes within the intestinal tract of parasitized carp included distension of the gut wall, epithelial compression and degeneration, pressure necrosis and varied inflammatory changes. These were most pronounced in regions containing the largest proportion of mature proglottids. Although the body lengths of parasitized and non-parasitized fish were not significantly different, parasitized fish were of lower body condition and reduced weight compared to non-parasitized conspecifics. Stable isotope analysis (δ15N and δ13C) revealed trophic impacts associated with infection, particularly for δ15N where values for parasitized fish were significantly reduced as their parasite burden increased. In a controlled aquarium environment where the fish were fed ad libitum on an identical food source, there was no significant difference in values of δ15N and δ13C between parasitized and non-parasitized fish. The growth consequences remained, however, with parasitized fish growing significantly slower than non-parasitized fish, with their feeding rate (items s−1) also significantly lower. Thus, infection by an introduced parasite had multiple pathological, ecological and trophic impacts on a host with no experience of the parasite. PMID:22022606

Application of an in vitro drug screening assay based on the release of phosphoglucose isomerase to determine the structure-activity relationship of thiazolides against Echinococcus multilocularis metacestodes.

PubMed

Stadelmann, Britta; Scholl, Sabrina; Müller, Joachim; Hemphill, Andrew

2010-03-01

The disease alveolar echinococcosis (AE), caused by the larval stage of the cestode Echinococcus multilocularis, is fatal if treatment is unsuccessful. Current treatment options are, at best, parasitostatic, and involve taking benzimidazoles (albendazole, mebendazole) for the whole of a patient's life. In conjunction with the recent development of optimized procedures for E. multilocularis metacestode cultivation, we aimed to develop a rapid and reliable drug screening test, which enables efficient screening of a large number of compounds in a relatively short time frame. Metacestodes were treated in vitro with albendazole, the nitro-thiazole nitazoxanide and 29 nitazoxanide derivatives. The resulting leakage of phosphoglucose isomerase (PGI) activity into the medium supernatant was measured and provided an indication of compound efficacy. We show that upon in vitro culture of E. multilocularis metacestodes in the presence of active drugs such as albendazole, the nitro-thiazole nitazoxanide and 30 different nitazoxanide derivatives, the activity of PGI in culture supernatants increased. The increase in PGI activity correlated with the progressive degeneration and destruction of metacestode tissue in a time- and concentration-dependent manner, which allowed us to perform a structure-activity relationship analysis on the thiazolide compounds used in this study. The assay presented here is inexpensive, rapid, can be used in 24- and 96-well formats and will serve as an ideal tool for first-round in vitro tests on the efficacy of large numbers of antiparasitic compounds.

Spatiotemporal distributions of intestinal helminths in female lesser scaup Aythya affinis during spring migration from the upper Midwest, USA

USGS Publications Warehouse

England, J. C.; Levengood, J.M.; Osborn, J. M.; Yetter, A. P.; Kinsella, J.M.; Cole, Rebecca A.; Cory D. Suski,; Hagy, Heath M.

2017-01-01

We examined the associations between intestinal helminth infracommunity structure and infection parameters and the age, size, and year and region of collection of 130 female lesser scaup (Aythya affinis) during their 2014–2015 spring migrations through the upper Midwest, USA. We identified a total of 647,174 individual helminths from 40 taxa, including 20 trematodes, 14 cestodes, 4 nematodes and 2 acanthocephalans parasitizing lesser scaup within the study area. Lesser scaup were each infected with 2–23 helminth taxa. One digenean, Plenosoma minimum, is reported for the first time in lesser scaup and in the Midwest. Mean trematode abundance and total helminth abundance was significantly less in 2015 than 2014, and we suspect that colder weather late in 2015 impacted the intermediate host fauna and caused the observed differences. Brillouin's species diversity of helminths was greatest in the northernmost region of the study area, which coincides with the range of a non-indigenous snail that indirectly causes annual mortality events of lesser scaup. While host age and size were not determined to be influential factors of helminth infracommunity structure, non-parametric ordination and permutational analysis of co-variance revealed that year and region of collection explained differences in helminth infracommunities. Our results suggest that spatiotemporal variations play an important role in the structure of intestinal helminth infracommunities found in migrating lesser scaup hosts, and may therefore impact host ability to build endogenous reserves at certain stopover locations in the Midwest.

Co-infections of the cestode Echinococcus vogeli and the nematode Calodium hepaticum in the hystricomorphic rodent Agouti paca from a forest reserve in Acre, Brazil.

PubMed

Almeida, F; Caldas, R; Corrêa, C; Rodrigues-Silva, R; Siqueira, N; Machado-Silva, J R

2013-12-01

The helminth fauna of Agouti paca (Linnaeus, 1766) has seldom been studied. In this paper, we report an unusual mixed infection of Echinococcus vogeli Rausch & Bernstein, 1972 and Calodium hepaticum (syn. Capillaria hepatica Bancroft, 1863) in free-ranging paca from a forested region in Acre (Brazil). Gross morphological examination revealed that paca liver contained multiple spherical to subspherical white or translucent lesions, which were isolated or frequently contiguous and partially covered by Glisson's capsule. Microscopic examination revealed unilocular cystic structures that contained abundant brood capsules in which numerous protoscolices budded from the inner surface. The protoscolices possessed rostellar hooks (33-41 μm in length), a morphological characteristic of the blade and calcareous corpuscles that is consistent with the metacestode E. vogeli. The diagnosis of C. hepaticum infection was based on the morphology and morphometry of the egg-shaped ellipsoids with bipolar plugs (44.8 ± 1.9 μm (length) × 24.4 ± 2.0 μm (width)) and liver histopathology. This finding expands the known range of C. hepaticum hosts in South America and, to the best of our knowledge, it is the first case of a mixed infection of E. vogeli and C. hepaticum. Furthermore, our data provide evidence that wild animal meat may be a source of C. hepaticum infection.

Helminth community of scaled quail (Callipepla squamata) from western Texas.

PubMed

Landgrebe, Jill N; Vasquez, Barbara; Bradley, Russell G; Fedynich, Alan M; Lerich, Scott P; Kinsella, John M

2007-02-01

Forty-eight scaled quail (Callipepla squamata) were collected during August 2002 at Elephant Mountain Wildlife Management Area in Brewster County, Texas, and examined for helminths. Eight species of helminths were found (5 nematodes and 3 cestodes), representing 2,811 individuals. Of these species, Gongylonema sp., Procyrnea pileata, and Choanotaenia infundibulum are reported from scaled quail for the first time. Prevalence of Aulonocephalus pennula, Gongylonema sp., Oxyspirura petrowi, Physaloptera sp., P. pileata, C. infundibulum, Fuhrmannetta sp., and Rhabdometra odiosa was 98, 2, 56, 4, 60, 2, 25, and 35%, respectively. Aulonocephalus pennula numerically dominated, accounting for 88% of total worms. Statistical analyses were performed on the 5 species with > or = 25% prevalence using the after-hatch-year host sample (n = 38). Prevalence of P. pileata was higher (P = 0.049) in females than in males and higher (P = 0.037) in the sample collected from the site that had spreader dams (berms 1-2 m high and 4-55 m long constructed in varying sizes to catch and retain rainfall) than the control site (no spreader dams). Higher rank mean abundance of A. pennula and O. petrowi (P = 0.0001 and P = 0.0052, respectively) was found in the host sample collected from the site that had spreader dams than the control site. A host gender-by-collection site interaction (P = 0.0215) was observed for P. pileata. Findings indicate that scaled quail are acquiring indirect life cycle helminths in arid western Texas habitats.

Identification of Hymenolepis diminuta Cysticercoid Larvae in Tribolium castaneum (Coleoptera: Tenebrionidae) Beetles from Iran.

PubMed

Makki, Mahsa Sadat; Mowlavi, Gholamreza; Shahbazi, Farideh; Abai, Mohammad Reza; Najafi, Faezeh; Hosseini-Farash, Bibi Razieh; Teimoori, Salma; Hasanpour, Hamid; Naddaf, Saied Reza

2017-06-01

Hymenolepis diminuta is a cestod of rodents and rarely infects humans. Infection in humans is via ingestion of infected insects. This study was aimed to detect H. diminuta cysticercoids in red flour beetles, Tribolium castaneum, and cockroaches originated from different regions of Iran. The red flour beetles and cockroaches were collected from local bakeries in five cities including Tehran, Ahvaz, Kazerun, and Sabzevar during 2010-2011. Some beetles and cockroaches were colonized in insectary and adults from F1 generation were fed on H. diminuta eggs. Both laboratory-infected and field-collected samples were dissected and examined for cysticercoids. Detection of H. diminuta DNA in T. castaneum beetles was performed by targeting a partial sequence of Ribosomal gene. Except the beetles from Ahvaz, all specimens were negative for cysticercoid by microscopy. Of the four dissected beetles from Ahvaz, one harbored 12 cysticercoids. Also, 110 (52%) of laboratory-infected beetles showed infection with an average of 12-14 larvae. None of the cockroaches was infected. Two beetles from Ahvaz, including the remainder of the microscopic positive specimen, yielded the expected amplicon in PCR assay. The H. diminuta DNA sequences generated in this study were identical and matched 97-100% with similar sequences from GenBank database. Lack of infection in the majority of beetles may reflect a low rat infestation rate in those areas, alternatively, the examined specimens might not have been the representative samples of the T. castaneum populations.

Identification of Hymenolepis diminuta Cysticercoid Larvae in Tribolium castaneum (Coleoptera: Tenebrionidae) Beetles from Iran

PubMed Central

Makki, Mahsa Sadat; Mowlavi, Gholamreza; Shahbazi, Farideh; Abai, Mohammad Reza; Najafi, Faezeh; Hosseini-Farash, Bibi Razieh; Teimoori, Salma; Hasanpour, Hamid; Naddaf, Saied Reza

2017-01-01

Background: Hymenolepis diminuta is a cestod of rodents and rarely infects humans. Infection in humans is via ingestion of infected insects. This study was aimed to detect H. diminuta cysticercoids in red flour beetles, Tribolium castaneum, and cockroaches originated from different regions of Iran. Methods: The red flour beetles and cockroaches were collected from local bakeries in five cities including Tehran, Ahvaz, Kazerun, and Sabzevar during 2010–2011. Some beetles and cockroaches were colonized in insectary and adults from F1 generation were fed on H. diminuta eggs. Both laboratory-infected and field-collected samples were dissected and examined for cysticercoids. Detection of H. diminuta DNA in T. castaneum beetles was performed by targeting a partial sequence of Ribosomal gene. Results: Except the beetles from Ahvaz, all specimens were negative for cysticercoid by microscopy. Of the four dissected beetles from Ahvaz, one harbored 12 cysticercoids. Also, 110 (52%) of laboratory-infected beetles showed infection with an average of 12–14 larvae. None of the cockroaches was infected. Two beetles from Ahvaz, including the remainder of the microscopic positive specimen, yielded the expected amplicon in PCR assay. The H. diminuta DNA sequences generated in this study were identical and matched 97–100% with similar sequences from GenBank database. Conclusion: Lack of infection in the majority of beetles may reflect a low rat infestation rate in those areas, alternatively, the examined specimens might not have been the representative samples of the T. castaneum populations. PMID:29062858

Parasitism in Pterois volitans (Scorpaenidae) from coastal waters of Puerto Rico, the Cayman Islands, and the Bahamas.

PubMed

Ramos-Ascherl, Zullaylee; Williams, Ernest H; Bunkley-Williams, Lucy; Tuttle, Lillian J; Sikkel, Paul C; Hixon, Mark A

2015-02-01

Recently, Pterois volitans, a Pacific species of lionfish, invaded the Atlantic Ocean, likely via the aquarium trade. We examined for internal and external parasites 188 individuals from 8 municipalities of Puerto Rico collected during 2009-2012, 91 individuals from Little Cayman, Cayman Islands, collected during the summers of 2010 and 2011, and 47 individuals from Lee Stocking Island, Bahamas, collected during the summer of 2009. In total, 27 parasite taxa were found, including 3 previously reported species from lionfish, the digenean Lecithochirium floridense, the leech Trachelobdella lubrica, and an Excorallana sp. isopod. We also report another 24 previously unreported parasite taxa from lionfish, including digeneans, monogeneans, cestodes, nematodes, isopods, a copepod, and an acanthocephalan. Among these parasites, several were previously unreported at their respective geographic origins: We report 5 new locality records from Puerto Rico, 9 from Cayman Islands, 5 from the Bahamas, 5 from the Caribbean, and 3 from the subtropical western Atlantic region. Three parasites are reported to associate with a fish host for the first time. The parasite faunas of P. volitans among our 3 study sites were quite different; most of the species infecting lionfish were generalists and/or species that infect carnivorous fishes. Although our study did not assess the impact of parasites on the fitness of invasive lionfish, it provides an important early step. Our results provide valuable comparative data for future studies at these and other sites throughout the lionfish's invaded range.

Taenia solium metacestode viability in infected pork after preparation with salt pickling or cooking methods common in Yucatán, Mexico.

PubMed

Rodriguez-Canul, R; Argaez-Rodriguez, F; de, la Gala D Pacheco; Villegas-Perez, S; Fraser, A; Craig, P S; Cob-Galera, L; Dominguez-Alpizar, J L

2002-04-01

The cestode parasite Taenia solium is an important cause of foodborne infection throughout tropical and subtropical regions. Ingestion of pork meat infected with T. solium larvae can lead to taeniasis infection in humans. With tourism and the consumption of native food increasing, it is important to investigate potential risks of transmission associated with food preparation methods. In this study, traditional Mexican salt pickling and two methods of pork preparation (as roast pork [cochinita pibil] and in pork and beans [frijol con puerco]) were evaluated in order to determine their effects on T. solium cyst viability in infected tissue. In the control groups, all metacestodes isolated were 100% viable, and only small changes in pH (from 6.0 to 5.9) and temperature (29 to 30 degrees C) were recorded. No viable cysts were detected after 12 and 24 h of salt pickling. The pH of the meat during salting dropped from 6.0 to 5.3. Osmotic changes and dehydration from the salting, rather than a change in pH, could be considered the main cause of cyst death. Temperatures of >65 degrees C damaged T. solium metacestodes in roast pork and in pork and beans. The results of this study indicate that if traditional pork dishes are prepared properly, T. solium cysts are destroyed. The criteria used in this study to evaluate the viability of tissue cysts are discussed.

Ultrastructural characters of the spermatozoon of the cestode Corallobothrium solidum Fritsch, 1886 (Cestoda: Proteocephalidea), a parasite of the electric catfish Malapterurus electricus.

PubMed

Brunanská, Magdaléna; Scholz, Tomás; Ibraheem, Mohammed Hassan

2004-12-01

The fine structure of the mature spermatozoon of the corallobothriine tapeworm Corallobothrium solidum Fritsch, 1886 (Cestoda: Proteocephalidea) from the electric catfish Malapterurus electricus from the Nile River in Egypt was studied by transmission electron microscopy for the first time. The filiform spermatozoon of C. solidum contains two axonemes of unequal length and a typical 9 + "1" trepaxonematan pattern. A single helicoidal crested body (30-200 nm thick) is localized at the anterior extremity of the gamete. The cortical microtubules line the periphery of the cell, largely parallel to the long axis of the spermatozoon and exhibiting signs of twisting at the beginning of region II. The nucleus, in the form of an electron-dense (largely in gametes of testes) and/or fibrous cord (largely in gametes from male reproductive ducts and seminal vesicle), coils in a spiral through the middle part (region III) of the spermatozoon. The cytoplasm contains electron-dense granules in regions II, III and partly in region IV. The cytoplasm of some spermatozoa exhibits an apparently higher electron-density at the end of the nucleated region (III), and continuously toward the middle part of region IV. The anterior and posterior extremities of the spermatozoa have a single axoneme. The ultrastructural features of the mature spermatozoon of C. solidum mostly coincide with those of the spermatozoon of other proteocephalideans, especially the gangesiine Electrotaenia malopteruri parasitizing the same host.

The parasitic fauna of the European bison (Bison bonasus) (Linnaeus, 1758) and their impact on the conservation. Part 1. The summarising list of parasites noted.

PubMed

Karbowiak, Grzegorz; Demiaszkiewicz, Aleksander W; Pyziel, Anna M; Wita, Irena; Moskwa, Bożena; Werszko, Joanna; Bień, Justyna; Goździk, Katarzyna; Lachowicz, Jacek; Cabaj, Władysław

2014-09-01

During the current century, 88 species of parasites have been recorded in Bison bonasus. These are 22 species of protozoa (Trypanosoma wrublewskii, T. theileri, Giardia sp., Sarcocystis cruzi, S. hirsuta, S. hominis, S. fusiformis, Neospora caninum, Toxoplasma gondii, Cryptosporidium sp., Eimeria cylindrica, E. subspherica, E. bovis, E. zuernii, E. canadensis, E. ellipsoidalis, E. alabamensis, E. bukidnonensis, E. auburnensis, E. pellita, E. brasiliensis, Babesia divergens), 4 trematodes species (Dicrocoelium dendriticum, Fasciola hepatica, Parafasciolopsis fasciolaemorpha, Paramphistomum cervi), 4 cestodes species (Taenia hydatigena larvae, Moniezia benedeni, M. expansa, Moniezia sp.), 43 nematodes species (Bunostomum trigonocephalum, B. phlebotomum, Chabertia ovina, Oesophagostomum radiatum, O. venulosum, Dictyocaulus filaria, D.viviparus, Nematodirella alcidis, Nematodirus europaeus, N. helvetianus, N. roscidus, N. filicollis, N. spathiger, Cooperia oncophora, C. pectinata, C. punctata, C. surnabada, Haemonchus contortus, Mazamastrongylus dagestanicus, Ostertagia lyrata, O. ostertagi, O. antipini, O. leptospicularis, O. kolchida, O. circumcincta, O. trifurcata, Spiculopteragia boehmi, S. mathevossiani, S. asymmetrica, Trichostrongylus axei, T. askivali, T. capricola, T. vitrinus, Ashworthius sidemi, Onchocerca lienalis, O. gutturosa, Setaria labiatopapillosa, Gongylonema pulchrum, Thelazia gulosa, T. skrjabini, T. rhodesi, Aonchotheca bilobata, Trichuris ovis), 7 mites (Demodex bisonianus, D. bovis, Demodex sp., Chorioptes bovis, Psoroptes equi, P. ovis, Sarcoptes scabiei), 4 Ixodidae ticks (Ixodes ricinus, I. persulcatus, I. hexagonus, Dermacentor reticulatus), 1 Mallophaga species (Bisonicola sedecimdecembrii), 1 Anoplura (Haematopinus eurysternus), and 2 Hippoboscidae flies (Lipoptena cervi, Melophagus ovinus). There are few monoxenous parasites, many typical for cattle and many newly acquired from Cervidae.

Gastrointestinal helminths in raccoons in Texas.

PubMed

Kresta, Amy E; Henke, Scott E; Pence, Danny B

2009-01-01

Raccoons (n=590) were collected from October 1999 to August 2003 from 35 counties across Texas, and gastrointestinal tracts were examined for helminth parasites. Prevalence was calculated and differences in mean abundance were examined among habitat ecoregions, age classes, and between sexes. Twenty different species of helminths (13 nematodes, two cestodes, two acanthocephalans, and three trematodes) were positively identified in the gastrointestinal tracts of 590 raccoons in Texas. Five of the 20 helminth species collected (Physaloptera rara, Placoconus lotoris, Molineus barbatus, Atriotaenia procyonis, and Macracanthorhynchus ingens) had a prevalence >20%. The total number of individuals of these five species (n=22,777) accounted for over 86% of the total number of individuals of all helminth species (n=26,426) collected. Subsequent analyses were based on these five helminths. Mean abundance differed among habitat ecoregions, age classes, and between sexes for all five parasites evaluated. This study is the most comprehensive statewide survey ever done of gastrointestinal helminths of raccoons across Texas. The five most prevalent helminths identified have all been reported in at least one previous survey, indicating that these parasites are not new to Texas and that raccoons are not naïve to the effects these parasites have on them. It may be helpful to wildlife rehabilitators, trappers, wildlife biologists, and other professionals to be aware of parasite abundance in raccoons from different areas of the state, as frequent human-raccoon interactions occur, and some of these parasites could be harmful to humans and domestic animals.

Development of LAMP assays for the molecular detection of taeniid infection in canine in Tibetan rural area.

PubMed

Feng, Kai; Li, Wei; Guo, Zhihong; Duo, Hong; Fu, Yong; Shen, Xiuying; Tie, Cheng; E, Rijie; Xiao, Changqin; Luo, Yanhong; Qi, Guo; Ni, Ma; Ma, Qingmei; Yamazaki, Wataru; Yoshida, Ayako; Horii, Yoichiro; Yagi, Kinpei; Nonaka, Nariaki

2017-12-22

For field-identification of taeniid cestodes in canine animals in Tibetan area, loop-mediated isothermal amplification (LAMP) assays for Echinococcus multilocularis, E. shiquicus, Taenia hydatigena, T. multiceps, T. pisiformis and T. crassiceps were developed and evaluated along with the reported assay for E. granulosus. The LAMP assays showed specific reaction with their corresponding target species DNA with the detection limit of 1 to 10 pg. Moreover, the assays for E. granulosus, E. multilocularis, T. hydatigena and T. multiceps could detect DNA extracted from 3 or more eggs of their corresponding target species. Then, the LAMP assays were applied on samples containing 3 to 35 taeniid eggs obtained from 61 field-collected canine feces in Qinghai, and the result was compared with a reported multiplex PCR and sequence analysis. The LAMP assays and the PCR detected single species DNA of E. granulosus, E. shiquicus, T. hydatigena and T. multiceps in 5, 2, 44 and 2 samples, respectively. In the rest 8 samples, DNA of both E. granulosus and T. hydatigena were detected by the PCR but the LAMP assays detected those DNAs in 2 samples and only T. hydatigena DNA in 6 samples. It was assumed that less than 3 E. granulosus eggs were mixed in the samples although the samples contained 21 to 27 eggs in total. In conclusion, the LAMP assays were less sensitive than the multiplex PCR, but would have adequate sensitivity for field use in Tibetan area.

Spatiotemporal distributions of intestinal helminths in female lesser scaup Aythya affinis during spring migration from the upper Midwest, USA.

PubMed

England, J C; Levengood, J M; Osborn, J M; Yetter, A P; Kinsella, J M; Cole, R A; Suski, C D; Hagy, H M

2017-07-01

We examined the associations between intestinal helminth infracommunity structure and infection parameters and the age, size, and year and region of collection of 130 female lesser scaup (Aythya affinis) during their 2014-2015 spring migrations through the upper Midwest, USA. We identified a total of 647,174 individual helminths from 40 taxa, including 20 trematodes, 14 cestodes, 4 nematodes and 2 acanthocephalans parasitizing lesser scaup within the study area. Lesser scaup were each infected with 2-23 helminth taxa. One digenean, Plenosoma minimum, is reported for the first time in lesser scaup and in the Midwest. Mean trematode abundance and total helminth abundance was significantly less in 2015 than 2014, and we suspect that colder weather late in 2015 impacted the intermediate host fauna and caused the observed differences. Brillouin's species diversity of helminths was greatest in the northernmost region of the study area, which coincides with the range of a non-indigenous snail that indirectly causes annual mortality events of lesser scaup. While host age and size were not determined to be influential factors of helminth infracommunity structure, non-parametric ordination and permutational analysis of co-variance revealed that year and region of collection explained differences in helminth infracommunities. Our results suggest that spatiotemporal variations play an important role in the structure of intestinal helminth infracommunities found in migrating lesser scaup hosts, and may therefore impact host ability to build endogenous reserves at certain stopover locations in the Midwest.

Ecotoxicoparasitology of the gastrointestinal tracts of pinnipeds: the effect of parasites on the potential bioavailability of total mercury (THg).

PubMed

McGrew, Ashley K; O'Hara, Todd M; Stricker, Craig A; Salman, Mo D; Van Bonn, William; Gulland, Frances M D; Whiting, Alex; Ballweber, Lora R

2018-08-01

Acanthocephalans, cestodes, and some species of nematodes acquire nutrients from the lumen contents in the gastrointestinal (GI) tract of their definitive host. These parasites are exposed to toxicants, such as mercury (Hg), through passive or active feeding mechanisms; therefore, the focus of this study was to determine if there is an effect of parasites on the dietary availability of total mercury (THg) within piscivorous pinniped hosts. THg concentrations ([THg]) in selected host tissues, parasites, and GI lumen contents from 22 California sea lions (Zalophus californianus), 15 ringed seals (Phoca hispida), and 4 spotted seals (Phoca largha) were determined. Among all pinnipeds, [THg] in acanthocephalans of the large intestine were significantly higher than concentrations in other samples (host lumen contents, other parasites and host intestinal wall), irrespective of location within the host GI tract. δ 15 N values of parasites depended both on parasite group and location within the GI tract. δ 15 N values were consistently higher in parasites inhabiting the large intestine, compared to elsewhere in the GI tract, for both sea lions and seals. δ 13 C values in parasites did not differ significantly from host GI tissues. Based on both [THg] and stable isotope values, parasites are likely affecting the Hg bioavailability within the GI lumen contents and host tissues, and toxicant-parasite interactions appear to depend on both parasitic taxon as well as their location within the host intestine. Copyright © 2018. Published by Elsevier B.V.

Generalized Taenia crassiceps cysticercosis in a chinchilla (Chinchilla lanigera).

PubMed

Basso, Walter; Rütten, Maja; Deplazes, Peter; Grimm, Felix

2014-01-17

Taenia crassiceps is a cestode parasite that uses carnivores as definitive hosts and rodents and rabbits as main intermediate hosts, but other animal species and humans may also get infected. One adult male chinchilla (Chinchilla lanigera) from an animal shelter in Switzerland presented widespread subcutaneous fluctuant swellings extended over the forehead, nose, face and thoracic regions with a progressive growth over 3 months. The thoracic swelling was surgically resected, and it consisted of numerous 3-4mm small transparent vesicles, mainly confined to the subcutaneous tissue, which were morphologically identified as cysticerci of T. crassiceps. The diagnosis was confirmed by PCR and DNA sequence analysis of fragments of the mitochondrial small subunit rRNA and NADH dehydrogenase subunit 1 genes. After 1.5 months, due to enlargement of the swollen areas and deterioration of the general health condition, the chinchilla was euthanized and a necropsy was performed. Thousands of small cysticerci were observed widespread in the subcutis, involving underlying musculature of the whole body, in the thoracic cavity, larynx, pharynx and in the retropharyngeal region. Additionally, three larger metacestodes were detected in the liver and morphologically and molecularly identified as Taenia taeniaeformis strobilocerci. The present case represents an indicator of the environmental contamination with Taenia eggs, highlighting the risk of infection for susceptible animals and humans. Besides the clinical relevance for pets, T. crassiceps is a zoonotic parasite and can be also cause of severe cysticercosis in humans. Copyright © 2013 Elsevier B.V. All rights reserved.

High morphological plasticity and global geographical distribution of the Pacific broad tapeworm Adenocephalus pacificus (syn. Diphyllobothrium pacificum): molecular and morphological survey.

PubMed

Hernández-Orts, Jesús Servando; Scholz, Tomáš; Brabec, Jan; Kuzmina, Tetiana; Kuchta, Roman

2015-09-01

The most important causative agent of human diphyllobothriosis in South America, Diphyllobothrium pacificum, is transferred to the original genus Adenocephalus Nybelin, 1931; revised and redescribed on the basis of the evaluation of an extensive material collected mainly from northern fur seal, Callorhinus ursinus, from St. Paul Island, Alaska. Detailed analysis of morphological and morphometrical data shows a high variability in most of the characteristics traditionally used in diagnosis of diphyllobothriid tapeworms. Phylogenetic analyses based on newly characterised sequences of mitochondrial cytochrome c oxidase subunit 1 and nuclear large subunit ribosomal RNA genes consistently reveal Adenocephalus pacificus as a sister lineage to the clade formed of the remaining Diphyllobothrium species and other genera (Digramma, Diplogonoporus, Ligula). Despite the generally similar morphology, A. pacificus can be differentiated from the closely related taxa in the presence of transverse papilla-like tegumental protuberances distributed anteriorly, separated by narrow semicircular grooves on the ventral surface of proglottids between their anterior margin and the anterior edge of the male gonopore, and relatively small eggs. A. pacificus displays a relatively low host specificity (found in 9 of 16 otariids, and in accidental hosts such as man, dog and jackal, the latter representing a new host) and a uniquely wide geographical distribution on both hemispheres. In addition, suitability of morphological criteria used in diagnostics of diphyllobothriid cestodes is discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of the complete mitochondrial genome of the cloacal tapeworm Cloacotaenia megalops (Cestoda: Hymenolepididae).

PubMed

Guo, Aijiang

2016-09-05

The cloacal tapeworm Cloacotaenia megalops (Hymenolepididae) is one of the most common cestode parasites of domestic and wild ducks worldwide. However, limited information is available regarding its epidemiology, biology, genetics and systematics. This study provides characterisation of the complete mitochondrial (mt) genome of C. megalops. The complete mt genome of C. megalops was obtained by long PCR, sequenced and annotated. The length of the entire mt genome of C. megalops is 13,887 bp; it contains 12 protein-coding, 2 ribosomal RNA and 22 transfer RNA genes, but lacks an atp8 gene. The mt gene arrangement of C. megalops is identical to that observed in Anoplocephala magna and A. perfoliata (Anoplocephalidae), Dipylidium caninum (Dipylidiidae) and Hymenolepis diminuta (Hymenolepididae), but differs from that reported in taeniids owing to the position shift between the tRNA (L1) and tRNA (S2) genes. The phylogenetic position of C. megalops was inferred using Maximum likelihood and Bayesian inference methods based on the concatenated amino acid data for 12 protein-coding genes. Phylogenetic trees showed that C. megalops is sister to Anoplocephala spp. (Anoplocephalidae) + Pseudanoplocephala crawfordi + Hymenolepis spp. (Hymenolepididae) indicating that the family Hymenolepididae is paraphyletic. The complete mt genome of C. megalops is sequenced. Phylogenetic analyses provided an insight into the phylogenetic relationships among the families Anoplocephalidae, Hymenolepididae, Dipylidiidae and Taeniidae. This novel genomic information also provides the opportunity to develop useful genetic markers for studying the molecular epidemiology, biology, genetics and systematics of C. megalops.

[Dipylidium caninum infection in an infant].

PubMed

Tsumura, Naoki; Koga, Hiroyasu; Hidaka, Hidenobu; Mukai, Fumiko; Ikenaga, Masaaki; Otsu, Yasushi; Masunaga, Kenji; Nagai, Kensuke; Yoneda, Yutaka; Fukuma, Toshihide; Ishimoto, Koji

2007-07-01

Dipylidium caninum, the dog tapeworm, is a common intestinal cestode of domestic dogs and cats, but few cases have been reported of human infection by this parasite in Japan. We repot a case of D. caninum infection in a 17 month-old girl, who sometimes had symptoms of abdominal pain, diarrhea, and dysphoria at night. Her mother noted the appearance of small white worms in her stool, and she was seen by a local pediatrician. Despite antiparasitic therapy wiht pyrantel pamoate, the problem persisted and was eventually referred for further workup to Kurume University Hospital. The diagnosis was made by microscopic examination of the excreted proglottids, which contained characteristic egg capsules. She was successfully treated with a singledose of praziquantel and four adult parasites were recovered. The longest intact worm was 32cm. Her family had household pets (a dog and a cat). The pets were seen by the local veterinary and both were evidenced D. caninum. Humans, primarily children, become infected when they accidentally ingest fleas. Parents usually find proglottids as multiple white objects, often described as cucumber, melon, or pumpkin seeds, in stool, diapers, or on the perineum. Most general practitioners and pediatricians may treat children with enterobiasis (pinworm) infection, and in case the treatment fails, other parasite infection should be considered such as this worm. A history of dog or cat pets, fleas, and flea bites may be important clues to diagnosis. Pets found to be infected should also be treated.

Gastrointestinal helminths (Cestoda, Chabertiidae and Heligmonellidae) of Pogonomys loriae and Pogonomys macrourus (Rodentia: Muridae) from Papua Indonesia and Papua New Guinea with the description of a new genus and two new species.

PubMed

Smales, L R

2014-11-28

Pieces of cestode, not indentified further, and 12 species of nematode including 1 new genus, 3 new species and 7 putative new species from the Families Chabertiidae and Heligmonellidae were collected from the digestive tracts of 16 Pogonomys loriae and 19 P. macrurous (Murinae: Hydromyini) from Papua, Indonesia and Papua New Guinea. The chabertiid Cyclodontostomum purvisi and the heligmonellid Odilia mackerrasae have been described previously from endemic murids. Hasanuddinia pogonomyos n. sp. can be distinguished from its congeners by the number of ridges in the synlophe, length of spicules and having a vagina with a dorsal diverticulum. Odilia dividua n. sp. is larger than its congeners, has a longer oesophagus, relatively shorter spicules and larger eggs. Pogonomystrongylus domaensis n. gen., n. sp. differs from all other genera in the Heligmonellidae in the characters of the synlophe, 7-10 ridges oriented sub frontally with a single left ventral ridge hypertrophied. Species richness of the nematode assemblages of P. loriae and P. macrourus are comparable to those of Abeomelomys sevia, Chiruromys vates and Coccymys rummleri when numbers of hosts examined are considered. Species composition was distinctive with 12, including the 7 putative species, of 14 species presently known only from species of Pogonomys. Similarities between the nematode fauna of endemic rodent hosts from Indonesia and Papua New Guinea were noted.

Ovicidal activity of different concentrations of Pochonia chlamydosporia chlamydospores on Taenia taeniaeformis eggs.

PubMed

Braga, F R; Silva, A R; Carvalho, R O; Araújo, J V; Pinto, P S A

2011-03-01

Three concentrations of chlamydospores of the nematophagous fungus Pochonia chlamydosporia (1000, 10,000 and 20,000 per Petri dish) were evaluated in vitro on Taenia taeniaeformis eggs. Chlamydospores at each concentration were cultured in two different media: 2% water-agar (2%WA) and 2% corn-meal-agar (2%CMA). Taenia taeniaeformis eggs were plated in each chlamydospore concentration in 2%WA and 2%CMA (treated groups) and without fungus (control group). Eggs were removed from each Petri dish at intervals of 7, 14 and 21 days and classified according to ovicidal activity (type 1, type 2 and type 3 effects). Plates containing 2%CMA showed the highest percentages for type 3 effect (81.3%) on the 21st day of observation. A difference (P < 0.01) between the media 2%WA and 2%CMA for type 1 effect was observed only at a concentration of 1000 chlamydospores on the 7th day. There were differences (P < 0.01) between 2%WA and 2%CMA on the 14th and 21st days, at the concentration of 20,000 chlamydospores, for type 1 and type 3 effects. Regression curves for type 3 effect in 2%WA and 2%CMA at the tested concentrations showed higher ovicidal activity with increasing chlamydospore concentrations. Results indicate that, at concentrations of 1000, 10,000 and 20,000 per Petri dish, chlamydospores of P. chlamydosporia effectively destroyed T. taeniaeformis eggs and can be considered a potential biological control agent for this cestode.

New records of helminths of Sceloporus pyrocephalus Cope (Squamata, Phrynosomatidae) from Guerrero and Michoacán, Mexico, with the description of a new species of Thubunaea Seurat, 1914 (Nematoda, Physalopteridae)

PubMed Central

de Oca, Edgar Uriel Garduño-Montes; López-Caballero, Jorge D.; Mata-López, Rosario

2017-01-01

Abstract A total of 61 specimens of the Red-headed Spiny Lizard Sceloporus pyrocephalus Cope (Phrynosomatidae) collected during the breeding season (June/July 2003, 2004 and 2005) from Western Mexico were examined for helminths. The morphological characterization of the helminths found was made through light microscopy and scanning electron microscopy. Nine taxa of helminths were identified, two cestodes: Mesocestoides sp. and Oochoristica sp., and seven nematodes: Parapharyngodon ayotzinapaensis Garduño-Montes de Oca, Mata-López & León-Règagnon, 2016, Parapharyngodon tikuinii Garduño-Montes de Oca, Mata-López & León-Règagnon, 2016, Parapharyngodon sp., Physalopterinae gen. sp., Skrjabinoptera scelopori Caballero-Rodríguez, 1971, Strongyluris similis Caballero, 1938 and a new species of Thubunaea Seurat, 1914. Larvae of Mesocestoides sp. and Physalopterinae gen. sp. were found in the body cavity and digestive tract, respectively. Excluding the species of Parapharyngodon Chatterji, 1933, S. pyrocephalus is recorded for the first time as a host of the remaining seven taxa of helminths. Additionally, Thubunaea leonregagnonae sp. n. is described and illustrated as a new nematode species, parasite of S. pyrocephalus from Mexico. This new species can be differentiated from the majority of its congeners by the absence of spicules, the particular pattern of caudal papillae in males and the small ratio of oesophagus length:male total body length (0.1–0.16). PMID:29290707

In vitro and in vivo effects of tamoxifen against larval stage Echinococcus granulosus.

PubMed

Nicolao, María Celeste; Elissondo, María Celina; Denegri, Guillermo M; Goya, Alejandra B; Cumino, Andrea C

2014-09-01

Cystic echinococcosis is a zoonotic infection caused by the larval stage of the cestode Echinococcus granulosus. Chemotherapy currently employs benzimidazoles; however, 40% of cases do not respond favorably. With regard to these difficulties, novel therapeutic tools are needed to optimize treatment in humans. The aim of this work was to explore the in vitro and in vivo effects of tamoxifen (TAM) against E. granulosus. In addition, possible mechanisms for the susceptibility of TAM are discussed in relation to calcium homeostasis, P-glycoprotein inhibition, and antagonist effects on a putative steroid receptor. After 24 h of treatment, TAM, at a low micromolar concentration range (10 to 50 μM), inhibited the survival of E. granulosus protoscoleces and metacestodes. Moreover, we demonstrated the chemotherapeutic and chemopreventive pharmacological effects of the drug. At a dose rate of 20 mg/kg of body weight, TAM induced protection against the infection in mice. In the clinical efficacy studies, a reduction in cyst weight was observed after the administration of 20 mg/kg in mice with cysts developed during 3 or 6 months, compared to that of those collected from control mice. Since the collateral effects of high TAM doses have been largely documented in clinical trials, the use of low doses of this drug as a short-term therapy may be a novel alternative approach for human cystic echinococcosis treatment. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Low sensitivity and frequent cross-reactions in commercially available antibody detection ELISA assays for Taenia solium cysticercosis.

PubMed

Garcia, Hector H; Castillo, Yesenia; Gonzales, Isidro; Bustos, Javier A; Saavedra, Herbert; Jacob, Louis; Del Brutto, Oscar H; Wilkins, Patricia P; Gonzalez, Armando E; Gilman, Robert H

2018-01-01

To evaluate the diagnostic performance of two commercially available ELISA kits, Novalisa ® and Ridascreen ® , for the detection of antibodies to Taenia solium, compared to serological diagnosis of neurocysticercosis (NCC) by LLGP-EITB (electro-immunotransfer blot assay using lentil-lectin purified glycoprotein antigens). Archive serum samples from patients with viable NCC (n = 45) or resolved, calcified NCC (n = 45), as well as sera from patients with other cestode parasites (hymenolepiasis, n = 45 and cystic hydatid disease, n = 45), were evaluated for cysticercosis antibody detection using two ELISA kits, Novalisa ® and Ridascreen ® . All NCC samples had previously tested positive, and all samples from heterologous infections were negative on LLGP-EITB for cysticercosis. Positive rates were calculated by kit and sample group and compared between the two kits. Compared to LLGP-EITB, the sensitivity of both ELISA assays to detect specific antibodies in patients with viable NCC was low (44.4% and 22.2%), and for calcified NCC, it was only 6.7% and 4.5%. Sera from patients with cystic hydatid disease were highly cross-reactive in both ELISA assays (38/45, 84.4%; and 25/45, 55.6%). Sera from patients with hymenolepiasis cross-reacted in five cases in one of the assays (11.1%) and in only one sample with the second assay (2.2%). The performance of Novalisa ® and Ridascreen ® was poor. Antibody ELISA detection cannot be recommended for the diagnosis of neurocysticercosis. © 2017 John Wiley & Sons Ltd.

A quick and simple method, usable in the field, for collecting parasites in suitable condition for both morphological and molecular studies.

PubMed

Justine, Jean-Lou; Briand, Marine J; Bray, Rodney A

2012-07-01

Many methods have been proposed for collecting and fixing parasites, but most were written before the molecular age, and were intended to be practised by experienced parasitologists in well-equipped laboratories. We describe here a very simple method, illustrated by photographs, for collecting helminths from the digestive tract of vertebrates. It only requires a few plastic vials, some ethanol and a means to heat water. Basically, the method consists of: (a) the extraction of all organs from the abdominal cavity; (b) opening the digestive system longitudinally; (c) agitate gut and contents in a saline solution (i.e. ca. 9% NaCl or 1/4 sea water in tap water); (d) decant in saline as many times as needed to clean contents; (e) immediately fix parasites in near-boiling saline; (f) discard saline and keep specimens in 95% ethanol. Additional information is given for collecting parasites from fish gills with a similar process. The method will collect most helminths (digeneans, larval cestodes, nematodes, acanthocephalans) from the digestive tract, and monogeneans and isopod and copepod crustaceans from fish gills. The specimens will be suitable for both morphological study and DNA sequencing. The method is simple, fast, inexpensive and can be used by untrained personnel, even in the field without electricity and without a binocular microscope. It can also be used by trained parasitologists who need to expedite treatment of abundant samples.

Patterns and processes influencing helminth parasites of Arctic coastal communities during climate change.

PubMed

Galaktionov, K V

2017-07-01

This review analyses the scarce available data on biodiversity and transmission of helminths in Arctic coastal ecosystems and the potential impact of climate changes on them. The focus is on the helminths of seabirds, dominant parasites in coastal ecosystems. Their fauna in the Arctic is depauperate because of the lack of suitable intermediate hosts and unfavourable conditions for species with free-living larvae. An increasing proportion of crustaceans in the diet of Arctic seabirds would result in a higher infection intensity of cestodes and acanthocephalans, and may also promote the infection of seabirds with non-specific helminths. In this way, the latter may find favourable conditions for colonization of new hosts. Climate changes may alter the composition of the helminth fauna, their infection levels in hosts and ways of transmission in coastal communities. Immigration of boreal invertebrates and fish into Arctic seas may allow the circulation of helminths using them as intermediate hosts. Changing migratory routes of animals would alter the distribution of their parasites, facilitating, in particular, their trans-Arctic transfer. Prolongation of the seasonal 'transmission window' may increase the parasitic load on host populations. Changes in Arctic marine food webs would have an overriding influence on the helminths' circulation. This process may be influenced by the predicted decreased of salinity in Arctic seas, increased storm activity, coastal erosion, ocean acidification, decline of Arctic ice, etc. Greater parasitological research efforts are needed to assess the influence of factors related to Arctic climate change on the transmission of helminths.

The discovery of acanthocephalans parasitizing chaetognaths.

PubMed

Lozano-Cobo, Horacio; Gómez-Gutiérrez, Jaime; Franco-Gordo, Carmen; Prado-Rosas, María Del Carmen Gómez Del

2017-06-01

A comprehensive literature review shows that 12 types of pathogens, micropredators and parasites are reported to interact with chaetognaths, mostly digenean trematodes, cestodes and nematodes larval stages. Through analysis of 78,152 chaetognaths from a monthly zooplankton time series (Jan 1996-Dec 1998) collected in the Mexican Central Pacific twelve acanthocephalan larvae parasitizing chaetognaths were discovered. This is the first record of an acanthocephalan parasitizing chaetognaths, raising to 13 the types of symbionts known to interact with them (excluding predators). Cystacanth larval specimens of Corynosoma sp. (Polymorphidae) were observed parasitizing the head, trunk and caudal cavities of three of the eight chaetognath species inhabiting this tropical coastal region (Flaccisagitta enflata, Flaccisagitta hexaptera and Zonosagitta bedoti). Because Corynosoma sp. parasitized chaetognaths during different months and years (Jan-Feb 1996, Mar and Jul 1997, Jan, Jun, Aug-Sep 1998) and because the total length of these cystacanths varied between 165-480 µm, suggesting growth inside the hosts, we conclude that chaetognaths are intermediate hosts of Corynosoma sp. The twelve parasitized chaetognaths were juveniles (without gonads) or immature adults (none in reproductively mature stage IV); therefore Corynosoma may have a negative influence on host reproduction. Marine crustaceans (amphipods, decapods, copepods, mysids and euphausiids) and fishes are common intermediate or paratenic hosts of acanthocephalans. Fish, sea birds and marine mammals are definitive hosts for marine Corynosoma species. The present discovery implies that acanthocephalans are transmitted trophically through different intermediate hosts (crustaceans, chaetognaths and/or fish); thus chaetognaths can also be part of the marine acanthocephalan life cycle.

Proteocephalus sinocyclocheili n. sp. (Cestoda: Proteocephalidae) in a fish Sinocyclocheilus grahami tingi Fang from Yunnan, China

NASA Astrophysics Data System (ADS)

Nie, Pin

1997-03-01

A new species of Proteocephalus from the fish Sinocyclocheilus grahami tingi, a subspecies endemic to Fuxian Lake in Southwest China, is described. This is the first report of cestode from this host. The new species differs from P. exiguus, P. Longicollis, P. parasiluri and P. torulosus, the only other species of Proteocephalus currently reported from China, by lacking an apical sucker, from P. exiguus by having 45 108 rather than 24 54 testes per proglottis, and a maximum of 15 rather than 28 uterine diverticula; from P.longicollis by having an average of 45 108 rather than 75 115 testes per proglottis and testes being in a single layer instead of 2 layers; and from P. torulosus by having 45 108 instead of 150 testes per proglottis and testes being in 3 4 layers; and from P. parasiluri by having 45 108 rather than 180 testes per proglottis. It resembles P. percae, P. pollanicola, and P. thymalli in number of testes and uterine diverticula, but differs by lacking an apical sucker. Proteocephalus thymalli, like the new species, has a vagina that opens dorsally to the cirrus sac, but P. thymalli slao has postovarian testes, which the new species lacks. The possible significance of parasitological examinations of the other two subspecies of S. grahami in two lakes close to Fuxian Lake is discussed in relation to host speciation and coevolution of the host-parasite system.

Landscape characteristics influence helminth infestations in a peri-domestic rodent--implications for possible zoonotic disease.

PubMed

Froeschke, Götz; Matthee, Sonja

2014-08-26

Anthropogenic habitat change often results in altered landscapes that can provide new environments where hosts, parasites and pathogens can interact. The latter can have implications for human and animal health when in close proximity to developed areas. We recorded the helminth species richness and level of infestation in the peri-domestic rodent, Rhabdomys pumilio, in three different human linked landscapes. The aim was, to investigate the potential of R. pumilio to act as a reservoir host for zoonotic helminths and to compare the effect of anthropogenic habitat change on its parasite infestation patterns. Rodents (n = 518) were trapped in natural areas (nature reserves) and in three human linked landscapes (crop, livestock and urban fragments). Gastrointestinal parasite burdens were recovered and helminths identified from each animal. Generalized linear models were applied to investigate the effect of different landscape types on helminth infestation. Rhabdomys pumilio was the most abundant rodent species within each landscape type. Eight helminths species were recovered and overall helminth prevalence was 86.68%. Mean helminth species richness, prevalence and abundance were significantly higher in crop fragments compared to natural landscapes and overall lower for nematodes in livestock and urban areas. Cestode prevalence showed a tendency to be elevated at anthropogenic linked landscape types. Host parameters and parasite infestations were strongly influenced by landscape characteristics. Resource-rich landscapes (crop fragments) provide favorable conditions for helminth infestations, while landscapes that are more closely associated with humans (livestock and urban landscapes) pose a larger risk by zoonotic species.

Factors affecting helminths community structure of the Egyptinan lizard Chalcides ocellatus (Forskal, 1775).

PubMed

Ibrahim, M M; Soliman, M F M

2005-12-01

The variation in the component community structure of intestinal helminths in the lizard Chalcides ocellatus (Forskal, 1775) was studied in relation to the seasonal variation and host weight and sex. 120 lizards were collected seasonally during year 2004, from Al Firdan, Ismailia governorate, Egypt. The helminths community consisted of six species (five nematodes and one cestode). The various helminths differed according to host sex. The prevalence of total helminths infection was 67.6 % while the prevalences of Thelandros schusteri, Pharyngodon mamillatus, Parapharyngodon bulbosus, Cosmocerca vrcibradici, Spauligodon petersi and Oochoristica maccoyi were 43.4%, 3.9 %, 13.2%, 5.3%, 6.6%, and 14.3%, respectively. The results showed that the season was the main factor affecting infracommunity species richness and parasite abundance. Moreover, there was interaction between season and host sex on abundance of P. bulbosus. The prevalence of intestinal helminths varied significantly in relation to host weight classes and sex in some species. Helminths abundance and intensity were independent from host sex. In addition, correlations were found between total helminths abundance and host weight. In conclusion, the helminths community of C. ocellatus was depauperate and the influence of the studied factors varied from species to another one. We cannot say if the low species richness and infection rates observed in the present study are typical of the host species or if they are due to characteristics of the study area, since no available data on parasite assemblages exist for other C. ocellatus populations.

Helminths of saiga antelope in Kazakhstan: implications for conservation and livestock production.

PubMed

Morgan, Eric R; Shaikenov, Blok; Torgerson, Paul R; Medley, Graham F; Milner-Gulland, E J

2005-01-01

Saiga antelope (Saiga tatarica) graze extensively on livestock pasture, potentially enabling transmission of a wide range of parasitic helminths between saigas and domestic ruminants. Thirty-six of the 38 species of helminth that have been found in saigas in Kazakhstan in the past have been found also in domestic livestock. We examined 133 saigas culled for meat in autumn 1997, and found three species of cestode and 12 nematodes (nine in the abomasum), but no trematodes or lungworms. The most abundant species were Marshallagia marshalli, Marshallagia mongolica, and Nematodirus gazellae in the abomasum, Nematodirus gazellae in the small intestine, and Skrjabinema ovis in the large intestine. There was no clear relationship between intensities of abomasal nematodes and body condition. Age-intensity patterns differed between species: N. gazellae intensities were highest in saigas around 2-3 yr old, and declined in older animals, whereas the intensity of Marshallagia spp. rose asymptotically with age. Fecal egg density was directly proportional to adult worm intensity across ages for Marshallagia spp., but only in young animals for N. gazellae. There was no evidence that helminths, at the intensities observed, adversely affect saiga populations. The host range of many of the parasites found is broad, and transmission between saigas and livestock in both directions might become important to agriculture and conservation as livestock numbers recover. Simplified sampling techniques used in this study, and statistical analysis based on bootstrapping, could prove useful in other parasitologic surveys of wildlife in remote areas.

New records of helminths of Sceloporus pyrocephalus Cope (Squamata, Phrynosomatidae) from Guerrero and Michoacán, Mexico, with the description of a new species of Thubunaea Seurat, 1914 (Nematoda, Physalopteridae).

PubMed

de Oca, Edgar Uriel Garduño-Montes; López-Caballero, Jorge D; Mata-López, Rosario

2017-01-01

A total of 61 specimens of the Red-headed Spiny Lizard Sceloporus pyrocephalus Cope (Phrynosomatidae) collected during the breeding season (June/July 2003, 2004 and 2005) from Western Mexico were examined for helminths. The morphological characterization of the helminths found was made through light microscopy and scanning electron microscopy. Nine taxa of helminths were identified, two cestodes: Mesocestoides sp. and Oochoristica sp., and seven nematodes: Parapharyngodon ayotzinapaensis Garduño-Montes de Oca, Mata-López & León-Règagnon, 2016, Parapharyngodon tikuinii Garduño-Montes de Oca, Mata-López & León-Règagnon, 2016, Parapharyngodon sp., Physalopterinae gen. sp., Skrjabinoptera scelopori Caballero-Rodríguez, 1971, Strongyluris similis Caballero, 1938 and a new species of Thubunaea Seurat, 1914. Larvae of Mesocestoides sp. and Physalopterinae gen. sp. were found in the body cavity and digestive tract, respectively. Excluding the species of Parapharyngodon Chatterji, 1933, S. pyrocephalus is recorded for the first time as a host of the remaining seven taxa of helminths. Additionally, Thubunaea leonregagnonae sp. n. is described and illustrated as a new nematode species, parasite of S. pyrocephalus from Mexico. This new species can be differentiated from the majority of its congeners by the absence of spicules, the particular pattern of caudal papillae in males and the small ratio of oesophagus length:male total body length (0.1-0.16).

Diversity of parasites of fish from the Upper Paraná River floodplain, Brazil.

PubMed

Takemoto, R M; Pavanelli, G C; Lizama, M A P; Lacerda, A C F; Yamada, F H; Moreira, L H A; Ceschini, T L; Bellay, S

2009-06-01

The aim of the present study was to provide a current survey of the species of parasites found in the Upper Paraná River floodplain, as well as to investigate which strategies and mechanisms used by parasites, are favored and which environmental factors influence the parasite community in the studied environments. During a seven-year period from February 2000 to September 2007, 3,768 fish belonging to 72 species were collected and analyzed for the purpose of studying the parasite fauna. A total of 337 species of parasites were reported, including 12 new descriptions: one myxosporid, Henneguya paranaensis Eiras, Pavanelli and Takemoto, 2004; eight monogeneans, Kritskyia annakohnae Boeger, Tanaka and Pavanelli, 2001; Kritskyia boegeri Takemoto, Lizama and Pavanelli, 2002; Kritskyia eirasi Guidelli, Takemoto and Pavanelli, 2003; Demidospermus labrosi França, Isaac, Pavanelli and Takemoto, 2003; Demidospermus mandi França, Isaac, Pavanelli and Takemoto, 2003; Pseudovancleaveus paranaensis França, Isaac, Pavanelli and Takemoto, 2003; Tereancistrum curimba Lizama, Takemoto and Pavanelli, 2004 and Tereancistrum toksonum Lizama, Takemoto and Pavanelli, 2004; two digeneans, Sanguinicola platyrhynchi Guidelli, Isaac and Pavanelli, 2002 and Dadayius pacupeva Lacerda, Takemoto and Pavanelli, 2003 and one cestode, Nomimoscolex pertierrae Chambrier, Takemoto and Pavanelli, 2005. In addition, several other species were reported for the first time in new hosts or in the floodplain. Monogeneans presented the highest number of species, followed by digeneans. The infection site with the highest species richness was the intestine, with 127 species.

Dynamics of a parasite assemblage of the Vermilion Rockfish Sebastes miniatus from northwestern Baja California, México

NASA Astrophysics Data System (ADS)

Rodríguez-Santiago, M. A.; Rosales-Casián, J. A.; Grano-Maldonado, M. I.

2014-06-01

A parasite assemblage of Sebastes miniatus from northwestern Baja California, México, was composed of a total of 12 species: five ectoparasites (two monogeneans and three parasitic copepods) and seven endoparasites (two digeneans, one cestode, three nematodes, and one acanthocephala). Five of these parasites constituted new genera records to the genus Sebastes, and nine were new geographic records. The most abundant species were the endoparasites Parabothriocephalus sagitticeps, Hysterothylacium sp., and Anisakis sp., and the specific richness ranged from 1 to 8 parasite species per host. The most important parasite species in terms of prevalence were Microcotyle sebastis (93 %) and Anisakis sp. (92 %). The mean abundance of parasites found in S. miniatus showed significant variations over the year, with maximum values (31.7 individuals/host) in August, and minimum (0.39 individuals/host) in February. P. sagitticeps showed the highest mean intensity of infection (190.4 parasites/host), followed by Anisakis sp. (127.2 parasites/host) and Hysterothylacium sp. (46.6 parasites/host). The presence of larval stages of the nematodes Anisakis, Pseudoterranova, and Hysterothylacium is particularly important due to their high abundance and prevalence and because they may represent a human health risk (anisakiasis). Rockfishes (family Scorpaenidae) of the genus Sebastes constitute one of the most important groundfish resources in the American and Mexican northern Pacific Ocean, both for recreational and for the commercial fisheries of California and Baja California. These rockfish species makes up a substantial part of the Mexican cuisine.

Helminth component community of the loggerhead sea turtle, Caretta caretta, from Madeira Archipelago, Portugal.

PubMed

Valente, Ana Luisa; Delgado, Cláudia; Moreira, Cláudia; Ferreira, Sandra; Dellinger, Thomas; Pinheiro de Carvalho, Miguel A A; Costa, Graça

2009-02-01

The helminth fauna of pelagic-stage loggerhead sea turtles, Caretta caretta, is still poorly known. Here, we describe the helminth-component community of healthy, free-ranging juvenile loggerhead sea turtles captured in the waters around Madeira Island, Portugal. Fifty-seven were used in this study. The esophagus, stomach, intestine, liver, gallbladder, spleen, kidneys, trachea, bronchi, urinary bladder, heart, left and right aortas, and coelomic cavity were macroscopically inspected; organs and tissues were removed and washed through a sieve. A search for parasites was made using a stereoscopic microscope; recovered parasites were fixed and stored in 70% alcohol until staining and identification. Prevalence, mean intensity, and mean abundance values were recorded. In total, 156 parasite specimens belonging to 9 species were found: nematodes included Anisakis simplex s.l. (larvae) and an unidentified species; digenetic trematodes present were Enodiotrema megachondrus, Rhytidodes gelatinosus, Pyelosomum renicapite, and Calycodes anthos; acanthocephalans included Bolbosoma vasculosum and Rhadinorhynchus pristis; a single cestode, Nybelinia sp., was present. Parasite infections were found to have both low prevalences and intensities. Possible reasons for this include the oligotrophic conditions of the pelagic habitat around Madeira; a 'dilution effect' because of the vastness of the area; and the small size, and thus ingestion rate, of the turtles. Results are discussed in terms of the various turtle populations that may use the waters surrounding Madeira. This work provides valuable information on the parasite fauna of a poorly known stage in the life of loggerhead sea turtles, thereby filling a fundamental gap with regard to features of the parasite fauna in this species.

Efficacy of osthole for Echinococcus granulosus in vitro and Echinococcus multilocularis in vivo.

PubMed

Yuan, Miaomiao; Luo, Yanping; Xin, Qi; Gao, Haijun; Zhang, Guochao; Jing, Tao

2016-08-15

Echinococcosis is a zoonotic infection caused by cestode species of the genus Echinococcus; in addition, this zoonosis has long been neglected as a parasitic disease and has limited treatment options. Clinical drugs such as benzimidazole derivatives have limited treatment efficacy. The current study evaluated a novel drug, osthole, with low toxicity and high activity against Echinococcus in vitro and in vivo. The results in vitro indicated that the viability of Echinococcus granulosus protoscoleces in the group treated with osthole (120μM) decreased by 100% within 3days. In vivo experiments were conducted using parasite-infected mice. For this purpose, three groups of infected mice were treated daily for 6 weeks with albendazole (ABZ, 100mg/kg, positive control group), osthole (100mg/kg, experimental group), or honey/PBS (100mg/kg, negative control group), respectively. The osthole- and ABZ-treated groups presented a significant reduction in wet weight of metacestodes, increase in the level of interleukin (IL)-4 and the percentage of eosinophils compared with the control group. Osthole exhibited a high activity against echinococcosis in vivo. In addition, the toxicity of osthole was evaluated via an in vitro 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, as well as via morphological observation and calculation of liver and kidney function indexes in vivo. No obvious toxic effects of osthole were observed in our study. Therefore, this novel drug may be a promising alternative to benzimidazole in anti-echinococcosis chemotherapy. Copyright © 2016 Elsevier B.V. All rights reserved.

Demographic and Ecological Effects on Patterns of Parasitism in Eastern Chimpanzees (Pan troglodytes schweinfurthii) in Gombe National Park, Tanzania

PubMed Central

Gillespie, Thomas R.; Lonsdorf, Elizabeth V.; Canfield, Elizabeth P.; Meyer, Derek J.; Nadler, Yvonne; Raphael, Jane; Pusey, Anne E.; Pond, Joel; Pauley, John; Mlengeya, Titus; Travis, Dominic A.

2014-01-01

From January 2006 to January 2008, we collected 1,045 fecal samples from 90 individually-recognized, free-ranging, eastern chimpanzees (Pan troglodytes schweinfurthii) inhabiting Gombe National Park, Tanzania to determine how patterns of parasitism are affected by demographic and ecological covariates. Seventeen parasite species were recovered, including eight nematodes (Oesophagostomum sp., Necator sp., Probstmayria gombensis, Strongyloides fulleborni, Ascaris sp., Trichuris sp., Abbreviata caucasica, and an unidentified strongyle), 1 cestode (Bertiella sp.), 1 trematode (Dicrocoeliidae), and 7 protozoa (Entamoeba coli, Entamoeba histolytica/dispar, Iodamoeba bütschlii, Troglodytella abrassarti, Troglocorys cava, Balantidium coli, and an unidentified protozoa). Significant differences were observed in interannual infection prevalence and parasite richness between 2006 and 2007. Intercommunity comparisons demonstrated higher prevalence of parasites for the Mitumba compared with Kasekela chimpanzee community. Prevalence of several parasites was strongly correlated with monthly rainfall patterns for both 2006 and 2007. Subadult chimpanzees had lower prevalence for most parasite species compared with adults in both years and also yielded a lower average parasite species richness. No significant differences were observed between males and females in prevalence in 2006. However, in 2007 the prevalence of S. fulleborni and I. bütschlii were higher in males than in females. Parasite prevalence and richness were substantially higher in this multiyear study compared with previous short-term studies of the gastrointestinal parasites of Gombe chimpanzees. This coupled with the significant interannual and interseasonal variation, demonstrated in this study, emphasizes the importance of multiyear monitoring with adequate sample size to effectively determine patterns of parasitism in wild primate populations. PMID:20623606

Reproductive potential of Schistocephalus solidus-infected male three-spined stickleback Gasterosteus aculeatus from two U.K. populations.

PubMed

Macnab, V; Katsiadaki, I; Barber, I

2009-11-01

Male three-spined stickleback Gasterosteus aculeatus from two U.K. populations with endemic infections of the cestode Schistocephalus solidus were brought into the laboratory prior to the breeding season and transferred to nesting tanks under conditions designed to stimulate sexual maturation. Nesting and courtship behaviours were scored over a 35 day period, after which fish were euthanized and the liver, spleen, kidney and gonads were weighed. Among G. aculeatus from a park pond in Leicester, U.K., infected males rarely engaged in reproductive behaviours and exhibited reduced indices of sexual development, body condition and general health, with effects being largely independent of relative parasite mass (parasite index, I(P)). In contrast, the reproductive behaviour of infected fish from Kendoon Loch in Dumfriesshire, U.K. appeared to be less severely affected, with infected fish regularly building nests and courting females under laboratory conditions. This was paralleled by a more limited effect of infection on physiological indicators of development, condition and general health. Furthermore, behavioural and physiological variables typically correlated with I(P) among infected fish from this population. Although comparing the performance of infected fish from the two populations directly was difficult due to potentially confounding factors, the results support the findings of recent studies showing that the effects of S. solidus on host reproduction are unlikely to be uniform across G. aculeatus populations. One possibility is that variation in the effects of infection arises from differences in the co-evolutionary association times of G. aculeatus with the parasite.

[Monoxenous and heteroxenous parasites of fish manipulate behavior of their hosts in different ways].

PubMed

Mikheev, V N

2011-01-01

Adaptive host manipulation hypothesis is usually supported by case studies on trophically transmitted heteroxenous endoparasites. Trematodes and cestodes are among efficient manipulators of fish, their common intermediate hosts. In this review paper, new data on modifications of host fish behavior caused by monoxenous ectoparasitic crustaceans are provided together with a review of effects caused by heteroxenous parasites. Differences in modifications of host behavior caused by heteroxenous and monoxenous parasites are discussed. Manipulation by heteroxenous parasites enhances availability of infected fish to predators--definitive hosts of the parasites. Fine-tuned synchronization of modified anti-predator behavior with a certain phase of the trematode Diplostomum spathaceum development in the eyes of fish, their second intermediate host, was shown. Modifications of behavior are habitat specific. When juvenile salmonids are in the open water, parasites impair their cooperative anti-predator behavior; in territorial bottom-dwelling salmonids, individual defense behavior such as sheltering is the main target of manipulation. It was shown that monoxenous ectoparasitic crustaceans Argulus spp. decreased motor activity, aggressiveness and increased shoal cohesiveness of infected fish. Such a behavior facilitates host and mate searching in these parasites, which often change their hosts, especially during reproduction. Reviewed experimental data suggest that heteroxenous parasites manipulate their host mainly through impaired defense behavior, e.g. impairing shoaling in fish. Alternatively, monoxenous parasites facilitate shoaling that is profitable for both parasites and hosts. Coordination of modified host behavior with the parasite life cycle, both temporal and spatial, is the most convincing criterion of the adaptive value of host manipulation.

Neglected diseases and ethnic minorities in the Western Pacific Region exploring the links.

PubMed

Schratz, Alexander; Pineda, Martha Fernanda; Reforma, Liberty G; Fox, Nicole M; Le Anh, Tuan; Tommaso Cavalli-Sforza, L; Henderson, Mackenzie K; Mendoza, Raymond; Utzinger, Jürg; Ehrenberg, John P; Tee, Ah Sian

2010-01-01

Ethnic minority groups (EMGs) are often subject to exclusion, marginalization and poverty. These characteristics render them particularly vulnerable to neglected diseases, a diverse group of diseases that comprise bacteria, ecto-parasites, fungi, helminths and viruses. Despite the health policy relevance, only little is known of the epidemiological profile of neglected diseases among EMGs. We reviewed country data from Australia, Cambodia, Lao People's Democratic Republic, Malaysia, the Philippines and Vietnam and found several overlaps between regions with high proportions of EMG population and high prevalence rates of neglected diseases (infections with soil-transmitted helminths, filarial worms, schistosomes, food-borne trematodes and cestodes). While the links are not always clearly evident and it is impossible to establish correlations among highly aggregated data without control variables-such as environmental factors-there appear indeed to be important linkages between EMGs, socio-economic status and prevalence of neglected diseases. Some determinants under consideration are lack of access to health care and general health status, poverty and social marginalization, as well as education and literacy. Further research is needed to deepen the understanding of these linkages and to determine their public health and socio-economic significance. In particular, there is a need for more data from all countries in the Western Pacific Region that is disaggregated below the provincial level. Selected case studies that incorporate other control variables-such as risk factors from the physical environment-might be useful to inform policy makers about the feasibility of prevention and control interventions that are targeted at high-risk EMGs.

Prevalence and co-infection of intestinal parasites among thai rural residents at high-risk of developing cholangiocarcinoma: a cross-sectional study in a prospective cohort study.

PubMed

Songserm, Nopparat; Promthet, Supannee; Wiangnon, Surapon; Sithithaworn, Paiboon

2012-01-01

Intestinal parasitic infections (IPIs) are still important to the health of Thai rural residents. IPIs are the cause of many chronic diseases with, for example, opisthorchiasis resulting in progression to cholangiocarcinoma (CCA). This cross-sectional study in a prospective cohort study aimed to examine the prevalence and co- infection of intestinal parasites among Northeastern Thai rural residents, recruited into the Khon Kaen Cohort Study (KKCS), and who were residing in areas of high-risk for developing CCA. On recruitment, subjects had completed questionnaires and provided fecal samples for IPI testing using the formalin ethyl acetate concentration technique. Data on selected general characteristics and the results of the fecal tests were analysed. IPI test results were available for 18,900 of cohort subjects, and 38.50% were found to be positive for one or more types of intestinal parasite. The prevalence of Opisthorchis viverrini (O. viverrini) infection was the highest (45.7%), followed by intestinal flukes (31.9%), intestinal nematodes (17.7%), intestinal protozoa (3.02%), and intestinal cestodes (1.69%). The pattern of different infections was similar in all age groups. According to a mapping analysis, a higher CCA burden was correlated with a higher prevalence of O. viverrini and intestinal flukes and a greater intensity of O. viverrini. Both prevention and control programs against liver fluke and other intestinal parasites are needed and should be delivered simultaneously. We can anticipate that the design of future control and prevention programmes will accommodate a more community-orientated and participatory approach.

The potential role of strongyloides robustus on parasite-mediated competition between two species of flying squirrels (Glaucomys).

PubMed

Krichbaum, Kristle; Mahan, Carolyn G; Steele, Michael A; Turner, Gregory; Hudson, Peter J

2010-01-01

There is growing evidence that populations of the northern flying squirrel (Glaucomys sabrinus) are declining in the eastern United States, perhaps due to competition with the southern flying squirrel (Glaucomys volans). Potential causes include parasite-mediated or apparent competition from the shared intestinal nematode, Strongyloides robustus, which has been shown to detrimentally affect the northern flying squirrel but not the southern flying squirrel. To investigate this hypothesis, we conducted a preliminary study on the parasite community of both flying squirrel species from sites in Pennsylvania where the two species occur sympatrically and where G. sabrinus is now considered endangered at the state level. We compared these parasite communities with those from northern flying squirrels from northern New York where the southern flying squirrel is absent. We found eight species of gastrointestinal parasites (Pterygodermatites peromysci, Lemuricola sciuri, Syphacia thompsoni, Syphacia spp., Capillaria spp., Citellinema bifurcatum, Strogyloides robustus, and an unidentifiable cestode species) in both species of flying squirrels examined for our study. The parasite-mediated competition hypothesis was partially supported. For example, in Pennsylvania, S. robustus was overdispersed in southern flying squirrels, such that a small proportion of the hosts carried a large proportion of the worm population. In addition, we found S. robustus to be present in northern flying squirrels when the species were sympatric, but not where southern flying squirrels were absent in New York. However, there was no association between S. robustus and the body condition of flying squirrels. We detected a potential parasite community interaction, as S. robustus abundance was positively associated with P. peromysci.

Macroparasite community of the Eurasian red squirrel (Sciurus vulgaris): poor species richness and diversity.

PubMed

Romeo, Claudia; Pisanu, Benoît; Ferrari, Nicola; Basset, Franck; Tillon, Laurent; Wauters, Lucas A; Martinoli, Adriano; Saino, Nicola; Chapuis, Jean-Louis

2013-10-01

The Eurasian red squirrel (Sciurus vulgaris) is the only naturally occurring tree squirrel throughout its range. We aim at improving current knowledge on its macroparasite fauna, expecting that it will have a poor parasite diversity because in species that have no sympatric congeners parasite richness should be lower than in hosts sharing their range with several closely related species, where host-switching events and lateral transmission are promoted. We examined gastro-intestinal helminth and ectoparasite communities (excluding mites) of, respectively, 147 and 311 red squirrel roadkills collected in four biogeographic regions in Italy and France. As expected, the macroparasite fauna was poor: we found five species of nematodes and some unidentified cestodes, three fleas, two sucking lice and two hard ticks. The helminth community was dominated by a single species, the oxyurid Trypanoxyuris (Rodentoxyuris) sciuri (prevalence, 87%; mean abundance, 373 ± 65 worms/host). Its abundance varied among seasons and biogeographic regions and increased with body mass in male hosts while decreased in females. The most prevalent ectoparasites were the flea Ceratophyllus (Monopsyllus) sciurorum (28%), whose presence was affected by season, and the generalist tick Ixodes (Ixodes) ricinus that was found only in France (34%). All the other helminths and arthropod species were rare, with prevalence below 10%. However, the first record of Strongyloides robustus, a common nematode of North American Eastern grey squirrels (S. carolinensis), in two red squirrels living in areas where this alien species co-inhabits, deserves further attention, since low parasite richness could result in native red squirrels being particularly vulnerable to parasite spillover.

Purification of native M. vogae and H. contortus tubulin by TOG affinity chromatography.

PubMed

Munguía, Beatriz; Teixeira, Ramiro; Veroli, Victoria; Melian, Elisa; Saldaña, Jenny; Minteguiaga, Mahia; Señorale, Mario; Marín, Mónica; Domínguez, Laura

2017-11-01

Microtubules are non-covalent cylindrical polymers formed by alpha- and beta-tubulin heterodimer units, crucial for cell division, intracellular transport, motility and differentiation. This makes them very attractive pharmacological targets exploited to develop different drugs such as anthelmintics, antifungals, and antineoplastics. In this work, in order to establish an in vitro target-based screen to integrate to the search for new anthelmintics, we explored the extraction of native assembly-competent tubulin from two helminth parasites: Mesocestoides vogae tetrathyridia (syn. corti, Cestoda: Cyclophyllidea), a useful cestode biological model, and Haemonchus contortus, a sheep gastrointestinal nematode of interest in livestock production. For this purpose, a novel tubulin affinity chromatography procedure was employed, based on the binding capacity of TOG (Tumor Overexpressed Gene) domain from MAPs (microtubule-associated proteins). The TOG domain of the protein Stu2 from Saccharomyces cerevisiae fused to GST (glutathione S- transferase) were produced in E. coli, and the immobilized recombinant proteins allowed for native tubulin extraction from parasites. The binding capacity of TOG1 affinity column (3.6%) was estimated using commercial porcine brain tubulin. A total amount of up to 126 μg of M. vogae tubulin was purified, whereas H. contortus tubulin co-eluted with glutamate dehydrogenase enzyme. The identity of tubulins was confirmed by western blotting and mass spectrometry. The abundance of tubulin estimated in M. vogae was 10% soluble extract, which probably could explain differences observed between tubulin purification results of both helminth parasites. Copyright © 2017 Elsevier Inc. All rights reserved.

Progress in the pharmacological treatment of human cystic and alveolar echinococcosis: Compounds and therapeutic targets

PubMed Central

Siles-Lucas, Mar; Casulli, Adriano; Cirilli, Roberto

2018-01-01

Human cystic and alveolar echinococcosis are helmintic zoonotic diseases caused by infections with the larval stages of the cestode parasites Echinococcus granulosus and E. multilocularis, respectively. Both diseases are progressive and chronic, and often fatal if left unattended for E. multilocularis. As a treatment approach, chemotherapy against these orphan and neglected diseases has been available for more than 40 years. However, drug options were limited to the benzimidazoles albendazole and mebendazole, the only chemical compounds currently licensed for treatment in humans. To compensate this therapeutic shortfall, new treatment alternatives are urgently needed, including the identification, development, and assessment of novel compound classes and drug targets. Here is presented a thorough overview of the range of compounds that have been tested against E. granulosus and E. multilocularis in recent years, including in vitro and in vivo data on their mode of action, dosage, administration regimen, therapeutic outcomes, and associated clinical symptoms. Drugs covered included albendazole, mebendazole, and other members of the benzimidazole family and their derivatives, including improved formulations and combined therapies with other biocidal agents. Chemically synthetized molecules previously known to be effective against other infectious and non-infectious conditions such as anti-virals, antibiotics, anti-parasites, anti-mycotics, and anti-neoplastics are addressed. In view of their increasing relevance, natural occurring compounds derived from plant and fungal extracts are also discussed. Special attention has been paid to the recent application of genomic science on drug discovery and clinical medicine, particularly through the identification of small inhibitor molecules tackling key metabolic enzymes or signalling pathways. PMID:29677189

Widespread co-endemicity of human cystic and alveolar echinococcosis on the eastern Tibetan Plateau, northwest Sichuan/southeast Qinghai, China.

PubMed

Li, Tiaoying; Chen, Xingwang; Zhen, Ren; Qiu, Jiamin; Qiu, Dongchuan; Xiao, Ning; Ito, Akira; Wang, Hu; Giraudoux, Patrick; Sako, Yasuhito; Nakao, Minoru; Craig, Philip S

2010-03-01

Cystic echinococcosis (CE) or hydatid disease is known to be cosmopolitan in its global distribution, while alveolar echinococcosis (AE) is a much rarer though more pathogenic hepatic parasitic disease restricted to the northern hemisphere. Both forms of human echinococcosis are known to occur on the Tibetan Plateau, but the epidemiological characteristics remain poorly understood. In our current study, abdominal ultrasound screening programs for echinococcosis were conducted in 31 Tibetan townships in Ganze and Aba Tibetan Autonomous Prefectures of northwest Sichuan Province during 2001-2008. Hospital records (1992-2006) in a major regional treatment centre for echinococcosis in Sichuan Province were also reviewed. Of 10,186 local residents examined by portable ultrasound scan, 645 (6.3%) were diagnosed with echinococcosis: a prevalence of 3.2% for CE, 3.1% for AE and 0.04% for dual infection (both CE and AE). Human cystic and alveolar echinococcosis in pastoral areas was highly co-endemic, in comparison to much lower prevalences in semi-pastoral or farming regions. The high ultrasound prevalence in these co-endemic areas in northwest Sichuan Province was also reflected in the hospital study, and hospital records furthermore indicated another possible highly co-endemic focus in Guoluo Prefecture of Qinghai Province, located at the border of northwest Sichuan. These chronic cestode zoonoses constitute an unparalleled major public health problem for pastoral Tibetan communities, and pose great difficulties for adequate treatment access and effective transmission control in such remote regions. Copyright 2009 Elsevier B.V. All rights reserved.

Human Taeniasis and cysticercosis in Asia.

PubMed

Ito, Akira; Nakao, Minoru; Wandra, Toni

2003-12-06

Human Taeniasis caused by the pork, Taenia solium, or beef, T saginata, tapeworm arises after eating pork or beef contaminated with metacestodes, the larval stage of these parasites. Taeniasis with T solium can lead to neurocysticercosis and threaten others by accidental ingestion of eggs released from asymptomatic Taeniasis patients. The 2003 World Health Assembly declared that T solium is of worldwide public-health importance, and that it is an eradicable parasitic disease worldwide. Adult taeniid tapeworms expelled from people in almost all Asian countries appeared to be T saginata (the so-called Asian Taenia), even though they ate pork. The organism is now named T asiatica, and has been found in Taiwan, Korea, China, Vietnam, and Indonesia. But it has been difficult to differentiate T saginata from beef and Asian Taenia from pork. Marshall Lightowlers and colleagues (Int J Parasitol 2003; 33: 1207-17) recently demonstrated that recombinant oncosphere vaccines against several taeniid cestodes, including T ovis, T saginata, T solium, and Echinococcus granulosus, are highly effective. Protection was almost 100%, in the laboratory and in the field. These researchers found several common features, including a predicted secretory signal sequence, and one or two copies of a fibronectin type III domain, each encoded by separate exons within the associated gene. WHERE NEXT? Molecular and immunological techniques, including vaccine research and development of animal models for differentiation of taeniid species in humans, have greatly advanced over the past decade. The clinical importance of infections by these taeniids, including T asiatica, in humans, and the potential for cysticercosis attributable to T asiatica in humans, needs further study.

The effect of praziquantel and Carica papaya seeds on Hymenolepis nana infection in mice using scanning electron microscope.

PubMed

Abou Shady, Omayma M; Basyoni, Maha M A; Mahdy, Olfat A; Bocktor, Nardden Zakka

2014-08-01

Hymenolepis nana (H. nana) is the most common tapeworm infection worldwide. It is more prevalent in warm climates where sanitation is poor, particularly among children. The effect and mechanism of action of praziquantel (PZQ), given at a dose of 25-mg/kg BW, and Carica papaya dried seed crude aqueous extract (CAE), given at a dose of 1.2-g/kg BW, were assessed on H. nana worms in experimentally infected mice. Tegumental changes were studied using the scanning electron microscope (SEM) and different parasitological parameters were observed. Each group of infected mice was divided into two subgroups. The first subgroup received either treatment before the 4th day after infection to investigate their effects on the cysticercoid stage. The other subgroup received treatments after the development of the adult stage, confirmed by eggs detection in stool. Both PZQ and C. papaya dried seed CAE resulted in a significant reduction of worm burden, total egg output and viable egg count. Marked tegumental changes were evident in adult worms treated with either treatment including shrinkage of the scolex and neck region with rostellar edema and complete loss of its hooks. However, all previous effects were exerted more rapidly in the case of PZQ treatment. They both significantly reduced cysticercoid stage size. Nevertheless, C. papaya outstand PZQ in having a deforming effect on adults arising from treated cysticercoids. It was concluded that C. papaya has significant anti-cestodal properties that enable its seed extract to be a very effective alternative to PZQ against H. nana.

Checklist of the helminth parasites of the genus Profundulus Hubbs, 1924 (Cyprinodontiformes, Profundulidae), an endemic family of freshwater fishes in Middle-America

PubMed Central

Pinacho-Pinacho, Carlos Daniel; García-Varela, Martín; Hernández-Orts, Jesús S.; Mendoza-Palmero, Carlos A.; Sereno-Uribe, Ana L.; Martínez-Ramírez, Emilio; Andrade-Gómez, Leopoldo; López-Jiménez, Alejandra; Hernández-Cruz, Eduardo; Pérez-Ponce de León, Gerardo

2015-01-01

Abstract From December 2012 to November 2014, 267 fish belonging to the family Profundulidae (representing nine of the 11 species of the genus Profundulus) were collected in 26 localities of Middle-America, across southern Mexico, Guatemala, and Honduras, comprising the distribution range of the genus, and analyzed for helminth parasites. Additionally, a database with all ten available published accounts of the helminth parasite fauna of this genus (the only genus within the family) was assembled. Based on both sources of information, a checklist containing all the records was compiled as a tool to address future questions in the areas of evolutionary biology, biogeography, ecology and phylogeography of this host-parasite association. The helminth parasite fauna of this fish group consists of 20 nominal species, classified in 17 genera and 14 families. It includes six species of adult digeneans, five metacercariae, two monogeneans, one adult cestode, three adult nematodes and three larval nematodes. The profundulid fishes are parasitized by a specialized group of helminth species (e.g. Paracreptotrema blancoi sensu Salgado-Maldonado et al. (2011b), Paracreptotrema profundulusi Salgado-Maldonado, Caspeta-Mandujano & Martínez Ramírez, 2011, Phyllodistomum spinopapillatum Pérez-Ponce de León, Pinacho-Pinacho, Mendoza-Garfias & García-Varela, 2015, Spinitectus humbertoi Mandujano-Caspeta & Moravec, 2000, Spinitectus mariaisabelae Caspeta-Mandujano Cabañas-Carranza & Salgado-Maldonado, 2007 and Rhabdochona salgadoi Mandujano-Caspeta & Moravec, 2000), representing the core helminth fauna that are not shared with other Middle-American fish species. PMID:26478697

Hymenolepis nana Impact Among Children in the Highlands of Cusco, Peru: An Emerging Neglected Parasite Infection.

PubMed

Cabada, Miguel M; Morales, Maria Luisa; Lopez, Martha; Reynolds, Spencer T; Vilchez, Elizabeth C; Lescano, Andres G; Gotuzzo, Eduardo; Garcia, Hector Hugo; White, Clinton A

2016-11-02

Hymenolepis nana is the most common cestode infection in the world. However, limited information is available regarding its impact on affected populations. We studied the epidemiology and symptoms associated with hymenolepiasis among children 3-16 years old in 16 rural communities of the highlands of the Cusco region in Peru. Information on demographics, socioeconomic status, symptoms as reported by parents, and parasitological testing was obtained from the database of an ongoing Fasciola hepatica epidemiologic study. A total of 1,230 children were included in the study. Forty-five percent were infected with at least one pathogenic intestinal parasite. Giardia spp. (22.9%) was the most common, followed by Hymenolepis (17.4%), Fasciola (14.1%), Ascaris lumbricoides (6.1%), and Strongyloides stercoralis (2%). The prevalence of Hymenolepis infection varied by community, by other parasitic infections, and by socioeconomic status. However, only years of education of the mother, use of well water, and age less than 10 years were associated with Hymenolepis infection in the multivariate analysis. Hymenolepis nana infection was associated with diarrhea, jaundice, headaches, fever, and fatigue. Children with > 500 eggs/g of stool were more likely to have symptoms of weight loss, jaundice, diarrhea, and fever. Hymenolepis nana infection and age were the only factors retained in the multivariate analysis modeling diarrhea. Hymenolepiasis is a common gastrointestinal helminth in the Cusco region and is associated with significant morbidity in children in rural communities. The impact caused by the emergence of Hymenolepis as a prevalent intestinal parasite deserves closer scrutiny. © The American Society of Tropical Medicine and Hygiene.

Hybridization between two cestode species and its consequences for intermediate host range

PubMed Central

2013-01-01

Background Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F1 hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii), both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively). Methods We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. Results We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Conclusions Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations. PMID:23390985

Parasite-specific IL-17-type cytokine responses and soluble IL-17 receptor levels in Alveolar Echinococcosis patients.

PubMed

Lechner, Christian J; Grüner, Beate; Huang, Xiangsheng; Hoffmann, Wolfgang H; Kern, Peter; Soboslay, Peter T

2012-01-01

Alveolar Echinococcosis (AE) caused by the cestode Echinococcus multilocularis, is a severe helminth infection of man, where unrestricted parasite growth will ultimately result in organ failure and fatality. The tissue-infiltrative growth of the larval metacestode and the limited efficacy of available drugs complicate successful intervention in AE; patients often need life-long medication, and if possible, surgical resection of affected tissues and organs. Resistance to AE has been reported, but the determinants which confer protection are not known. ln this study, we analyzed in patients at distinct stages of Alveolar Echirococcosis, that is cured, stable and progressive AE, as well as in infection-free controls, the cellular production and plasma levels of pro-inflammatory cytokines lL-17A, lL-17B, lL-17F and their soluble receptors lL-17RA (slL-17RA) and IL-17RB (sIL-17RB). Significantly elevated levels of IL-17B and slL-17RB were observed, whilst lL-17F and slL-17RA were reduced in patients with AE. Similarly, the cellular production of lL-17F and slL-L7RA in response to E. multilocularis antigens was low in AE patients, while levels of slL-17RB were highly enhanced. These observations suggest immune-modulating properties of E. multitocularis on lL-17 cytokine-mediated pro-inflammatory immune responses; this may facilitate the tissue infiltrative growth of the parasite and its persistence in the human host.

Sequencing, bioinformatic characterization and expression pattern of a putative amino acid transporter from the parasitic cestode Echinococcus granulosus.

PubMed

Camicia, Federico; Paredes, Rodolfo; Chalar, Cora; Galanti, Norbel; Kamenetzky, Laura; Gutierrez, Ariana; Rosenzvit, Mara C

2008-03-31

We have sequenced and partially characterized an Echinococcus granulosus cDNA, termed egat1, from a protoscolex signal sequence trap (SST) cDNA library. The isolated 1627 bp long cDNA contains an ORF of 489 amino acids and shows an amino acid identity of 30% with neutral and excitatory amino acid transporters members of the Dicarboxylate/Amino Acid Na+ and/or H+ Cation Symporter family (DAACS) (TC 2.A.23). Additional bioinformatics analysis of EgAT1, confirmed the results obtained by similarity searches and showed the presence of 9 to 10 transmembrane domains, consensus sequences for N-glycosylation between the third and fourth transmembrane domain, a highly similar hydropathy profile with ASCT1 (a known member of DAACS family), high score with SDF (Sodium Dicarboxilate Family) and similar motifs with EDTRANSPORT, a fingerprint of excitatory amino acid transporters. The localization of the putative amino acid transporter was analyzed by in situ hybridization and immunofluorescence in protoscoleces and associated germinal layer. The in situ hybridization labelling indicates the distribution of egat1 mRNA throughout the tegument. EgAT1 protein, which showed in Western blots a molecular mass of approximately 60 kD, is localized in the subtegumental region of the metacestode, particularly around suckers and rostellum of protoscoleces and layers from brood capsules. The sequence and expression analyses of EgAT1 pave the way for functional analysis of amino acids transporters of E. granulosus and its evaluation as new drug targets against cystic echinococcosis.

Effect of praziquantel on adult Echinococcus granulosus in vitro: scanning electron microscopy.

PubMed

Conder, G A; Marchiondo, A A; Andersen, F L

1981-01-01

The effect of praziquantel in vitro at concentrations of 5, 50 and 500 ppm for 1 h resulted in the progressive breakdown of the tegument and in morphologic distortion of adult Echinococcus granulosus when compared to controls. Scanning electron microscopy of all specimens treated in the various concentrations of praziquantel showed loss of most, if not all of the rostellar hooks and changes in the structure of the suckers. Many of the tapeworms immediately detached from the host's gut upon being placed in the drug, and all treated cestodes exhibited contraction or swelling, particularly in the penultimate proglottid. Intense contraction was apparent in the worms exposed to the higher drug concentrations. Characteristic conical microtriches on the terminal proglottid, as observed in the control specimens, became fused and matted when exposed to 5 ppm of praziquantel. At a drug concentration of 50 ppm, the tegumental surface developed grooves or furrows between clumps of fused microtriches, while 500 ppm caused production of holes within the denuded tegument of the parasite. Ovoid bodies, presumed to be eggs, were observed on the outer surfaces and just below the tegument of tapeworms treated with concentrations of 50 ppm. These structures also appeared to adhere to the outer surfaces of specimens exposed to 500 ppm. In view of the foregoing, special care should be taken in handling and disposing of feces from infected or suspect dogs after praziquantel treatment, since the breakdown in the tegumental surface of E. granulosus presumably results in the release of potentially infective eggs.

Androgens Exert a Cysticidal Effect upon Taenia crassiceps by Disrupting Flame Cell Morphology and Function

PubMed Central

Ambrosio, Javier R.; Valverde-Islas, Laura; Nava-Castro, Karen E.; Palacios- Arreola, M. Isabel; Ostoa-Saloma, Pedro; Reynoso-Ducoing, Olivia; Escobedo, Galileo; Ruíz-Rosado, Azucena; Dominguez-Ramírez, Lenin; Morales-Montor, Jorge

2015-01-01

The effects of testosterone (T4) and dihydrotestosterone (DHT) on the survival of the helminth cestode parasite Taenia crassiceps, as well as their effects on actin, tubulin and myosin expression and their assembly into the excretory system of flame cells are described in this paper. In vitro evaluations on parasite viability, flow cytometry, confocal microscopy, video-microscopy of live flame cells, and docking experiments of androgens interacting with actin, tubulin, and myosin were conducted. Our results show that T4 and DHT reduce T. crassiceps viability in a dose- and time-dependent fashion, reaching 90% of mortality at the highest dose used (40 ng/ml) and time exposed (10 days) in culture. Androgen treatment does not induce differences in the specific expression pattern of actin, tubulin, and myosin isoforms as compared with control parasites. Confocal microscopy demonstrated a strong disruption of the parasite tegument, with reduced assembly, shape, and motion of flame cells. Docking experiments show that androgens are capable of affecting parasite survival and flame cell morphology by directly interacting with actin, tubulin and myosin without altering their protein expression pattern. We show that both T4 and DHT are able to bind actin, tubulin, and myosin affecting their assembly and causing parasite intoxication due to impairment of flame cell function. Live flame cell video microscopy showing a reduced motion as well changes in the shape of flame cells are also shown. In summary, T4 and DHT directly act on T. crassiceps cysticerci through altering parasite survival as well as the assembly and function of flame cells. PMID:26076446

Molecular phylogeny of the genus Taenia (Cestoda: Taeniidae): proposals for the resurrection of Hydatigera Lamarck, 1816 and the creation of a new genus Versteria.

PubMed

Nakao, Minoru; Lavikainen, Antti; Iwaki, Takashi; Haukisalmi, Voitto; Konyaev, Sergey; Oku, Yuzaburo; Okamoto, Munehiro; Ito, Akira

2013-05-01

The cestode family Taeniidae generally consists of two valid genera, Taenia and Echinococcus. The genus Echinococcus is monophyletic due to a remarkable similarity in morphology, features of development and genetic makeup. By contrast, Taenia is a highly diverse group formerly made up of different genera. Recent molecular phylogenetic analyses strongly suggest the paraphyly of Taenia. To clarify the genetic relationships among the representative members of Taenia, molecular phylogenies were constructed using nuclear and mitochondrial genes. The nuclear phylogenetic trees of 18S ribosomal DNA and concatenated exon regions of protein-coding genes (phosphoenolpyruvate carboxykinase and DNA polymerase delta) demonstrated that both Taenia mustelae and a clade formed by Taenia parva, Taenia krepkogorski and Taenia taeniaeformis are only distantly related to the other members of Taenia. Similar topologies were recovered in mitochondrial genomic analyses using 12 complete protein-coding genes. A sister relationship between T. mustelae and Echinococcus spp. was supported, especially in protein-coding gene trees inferred from both nuclear and mitochondrial data sets. Based on these results, we propose the resurrection of Hydatigera Lamarck, 1816 for T. parva, T. krepkogorski and T. taeniaeformis and the creation of a new genus, Versteria, for T. mustelae. Due to obvious morphological and ecological similarities, Taenia brachyacantha is also included in Versteria gen. nov., although molecular evidence is not available. Taenia taeniaeformis has been historically regarded as a single species but the present data clearly demonstrate that it consists of two cryptic species. Copyright © 2013 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Taenia solium tapeworms synthesize corticosteroids and sex steroids in vitro.

PubMed

Valdez, R A; Jiménez, P; Fernández Presas, A M; Aguilar, L; Willms, K; Romano, M C

2014-09-01

Cysticercosis is a disease caused by the larval stage of Taenia solium cestodes that belongs to the family Taeniidae that affects a number of hosts including humans. Taeniids tapeworms are hermaphroditic organisms that have reproductive units called proglottids that gradually mature to develop testis and ovaries. Cysticerci, the larval stage of these parasites synthesize steroids. To our knowledge there is no information about the capacity of T. solium tapeworms to metabolize progesterone or other precursors to steroid hormones. Therefore, the aim of this paper was to investigate if T. solium tapeworms were able to transform steroid precursors to corticosteroids and sex steroids. T. solium tapeworms were recovered from the intestine of golden hamsters that had been orally infected with cysticerci. The worms were cultured in the presence of tritiated progesterone or androstenedione. At the end of the experiments the culture media were analyzed by thin layer chromatography. The experiments described here showed that small amounts of testosterone were synthesized from (3)H-progesterone by complete or segmented tapeworms whereas the incubation of segmented tapeworms with (3)H-androstenedione, instead of (3)H-progesterone, improved their capacity to synthesize testosterone. In addition, the incubation of the parasites with (3)H-progesterone yielded corticosteroids, mainly deoxicorticosterone (DOC) and 11-deoxicortisol. In summary, the results described here, demonstrate that T. solium tapeworms synthesize corticosteroid and sex steroid like metabolites. The capacity of T. solium tapeworms to synthesize steroid hormones may contribute to the physiological functions of the parasite and also to their interaction with the host. Copyright © 2014 Elsevier Inc. All rights reserved.

Prevalence of Fleas and Gastrointestinal Parasites in Free-Roaming Cats in Central Mexico

PubMed Central

Cantó, Germinal J.; Guerrero, Roberto I.; Olvera-Ramírez, Andrea M.; Milián, Feliciano; Mosqueda, Juan; Aguilar-Tipacamú, Gabriela

2013-01-01

The prevalence of fleas and gastrointestinal parasites in free-roaming and domestic cats in central Mexico was evaluated. Three hundred and fifty eight cats captured in the street or brought in by owners to the Animal Control Center Unit, a unit of State Government, from June 2010 to May 2011, were included in the study. All cats were examined for the presence of fleas and gastrointestinal worms. One-hundred and ninety (53%) cats were infested with at least one flea species. Single infestations were observed in 106 (30%) cats and mixed infestations in 84 (23%) cats. Four species of fleas were recovered: Ctenocephalides felis in 53% of the cats, C. canis in 18%, Echidnophaga gallinacea in 7% and Pulex irritans in 1%. One-hundred and sixty three (45%) cats were infected with one or more species of gastrointestinal parasites: 48 (13%) with nematodes, 145 (40%) with cestodes, and one animal presented Moniliformis moniliformis. Prevalences and mean intensity of infection were: Physaloptera praeputialis 7 and 18; T. cati 3 and 2; Ancylostoma tubaeforme 2.5 and 2; Toxascaris leonina 0.5 and 2; Dipylidium caninum 36 and 32; Taenia taeniformis 4 and 3 and Moniliformis moniliformis 0.3 and 106, respectively. There was significant association (P<0.01), between season and ectoparasites load, more fleas were obtained in the summer and autumn than in the winter and spring; however, no statistical difference was observed for endoparasites load (P>0.05). The correlation between the total number of ectoparasites and endoparasites was not significant (r = 0.089, P = 0.094). PMID:23573282

First description of Echinococcus ortleppi and cystic echinococcosis infection status in Chile.

PubMed

Corrêa, Felipe; Stoore, Caroll; Horlacher, Pamina; Jiménez, Mauricio; Hidalgo, Christian; Alvarez Rojas, Cristian A; Figueiredo Barros, Guilherme; Bunselmeyer Ferreira, Henrique; Hernández, Marcela; Cabrera, Gonzalo; Paredes, Rodolfo

2018-01-01

Cystic echinococcosis (CE), a parasitic disease caused by the cestode Echinococcus granulosus sensu lato (s.l.), is a worldwide zoonotic infection. Although endemic in Chile, information on the molecular characteristics of CE in livestock remains scarce. Therefore we aimed to describe the status of infection with E. granulosus s.l. in cattle from central Chile and also to contribute to the study of the molecular epidemiology of this parasite. According to our results, the prevalence of CE is 18.84% in cattle, similar to previous reports from Chile, suggesting that the prevalence in Santiago Metropolitan area has not changed in the last 30 years. Most of the cysts were found only in lungs (51%), followed by concurrent infection in liver and lungs (30%), and only liver (19%). Molecular characterization of the genetic diversity and population structure of E. granulosus s.l. from cattle in central Chile was performed using a section of the cytochrome c oxidase subunit 1 (cox1) mitochondrial gene. E. granulosus sensu stricto (s.s.) (G1-G3 genotypes) was confirmed by RFLP-PCR to be the dominant species affecting cattle (284 samples/290 samples); we also report for the first time in Chile the presence of E. ortleppi (G5 genotype) (2 samples/61 samples). The Chilean E. granulosus s.s. parsimony network displayed 1 main haplotype. Additional studies using isolates from many locations across Chile and different intermediate hosts will provide more data on the molecular structure of E. granulosus s.s. within this region. Likewise, investigations of the importance of E. ortleppi in human infection in Chile deserve future attention.

Fine structure of the uterus in tapeworm Tetrabothrius erostris (Cestoda: Tetrabothriidea).

PubMed

Korneva, Janetta V; Jones, Malcolm K; Kuklin, Vadim V

2014-12-01

The uterine organization in Tetrabothrius erostris (Tetrabothriidea) was investigated by the methods of transmission and scanning electron microscopy. In sexually mature proglottids, the uterine wall consists of a syncytial epithelium (1.4-2.5 μm thick, except in regions containing nuclei). The ribosomes, mitochondria and numerous cisternae of granular endoplasmic reticulum with concentric or parallel profiles with electron lucent material are observed in the epithelium. The uterine wall is characterized by the abundance of lipid droplets that are localized inside the long protrusions of the uterine epithelium (called fungiform papillae) up to 15-17 μm and in the surrounding medullary parenchyma. The protrusions with lipid droplets in the proximal ends of the uterus are located closely to each other. A basal matrix (up to 0.6 μm thick) supports the uterine epithelium. The musculature consisting of 1-2 muscle layers is well developed; large myocytons are connected with the myofibrils and have a nucleus that reaches 4 μm in size. In gravid proglottids, the epithelium without nuclei is reduced to 0.2-1.6 μm thick. The number of protrusions of the uterine epithelium and lipid droplets in the epithelial layer decreases. Sparse small muscle bundles underlay the uterine wall at this stage; the basal matrix is feebly marked. The matrotrophy or the support by nutrition from the parent organism to embryos is discussed for T. erostris which belongs to oligolecital cestodes and possesses numerous lipid droplets in the uterine wall during the development of embryos.

Comparative studies on Pb and Cd levels in parasites of terrestrial and aquatic animals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sures, B.; Taraschewski, H.

1995-12-31

Several fish parasites (Acanthocephala, Cestoda, Nematoda) and organs of their respective intermediate and final hosts were analyzed for heavy metals by electrothermal atomic absorption spectrometry (ET-AAS). Pb and Cd were also quantified in the liver fluke Fasciola hepatica as well as in different organs of the large intestinal roundworm Ascaris suum. The levels of these heavy metals in the parasites were compared to those of muscle, liver, kidney and intestine of the respective definitive hosts cattle and swine obtained from a slaughter house. Most parasites accumulated significantly higher levels of metals than their final hosts. This was most conspicuous inmore » acanthocephalans which contained up to 3 {times} 10{sup 3} fold more lead than the muscle of their fish hosts and up to 1.1 {times} 10{sup 4} more lead than the water surrounding the fish. In these helminths cadmium was enriched up to 400 fold compared to the muscle of the fish and up to 2.7 {times} 10{sup 4} compared to the water. In contrast to the accumulation capacity of adult acanthocephalans their larvae contained about 30 to 180 times less Pb and Cd. Thus, the predominant accumulation of both metals appears in the adult worms. The cestodes of fish and the liver flukes of cattle accumulated the metals up to 200 fold compared to the muscle of their hosts. The nematodes did not contain higher levels of the metals than their hosts. Thus, parasites, especially acanthocephalans, seem to be sensitive bioindicators of Pb and Cd in their environments.« less

The pink shrimp Farfantepenaeus duorarum, its symbionts and helminths as bioindicators of chemical pollution in Campeche Sound, Mexico.

PubMed

Vidal-Martínez, V M; Aguirre-Macedo, M L; Del Rio-Rodríguez, R; Gold-Bouchot, G; Rendón-von Osten, J; Miranda-Rosas, G A

2006-06-01

The pink shrimp Farfantepenaeus duorarum may acquire pollutants, helminths and symbionts from their environment. Statistical associations were studied between the symbionts and helminths of F. duorarum and pollutants in sediments, water and shrimps in Campeche Sound, Mexico. The study area spatially overlapped between offshore oil platforms and natural shrimp mating grounds. Spatial autocorrelation of data was controlled with spatial analysis using distance indices (SADIE) which identifies parasite or pollutant patches (high levels) and gaps (low levels), expressing them as clustering indices compared at each point to produce a measure of spatial association. Symbionts included the peritrich ciliates Epistylis sp. and Zoothamnium penaei and all symbionts were pooled. Helminths included Hysterothylacium sp., Opecoeloides fimbriatus, Prochristianella penaei and an unidentified cestode. Thirty-five pollutants were identified, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides and heavy metals. The PAHs (2-3 ring) in water, unresolved complex mixture (UCM), Ni and V in sediments, and Zn, Cr and heptachlor in shrimps were significantly clustered. The remaining pollutants were randomly distributed in the study area. Juvenile shrimps acquired pesticides, PAHs (2-3 rings) and Zn, while adults acquired PAHs (4-5 rings), Cu and V. Results suggest natural PAH spillovers, and continental runoff of dichlorodiphenyltrichloroethane (DDT), PCBs and PAHs (2-3 ring). There were no significant associations between pollutants and helminths. However, there were significant negative associations of pesticides, UCM and PCBs with symbiont numbers after controlling shrimp size and spatial autocorrelation. Shrimps and their symbionts appear to be promising bioindicators of organic chemical pollution in Campeche Sound.

Helminth Fauna in Captive European Gray Wolves (Canis lupus lupus) in Germany.

PubMed

Bindke, Johanna Daniela; Springer, Andrea; Böer, Michael; Strube, Christina

2017-01-01

Captive as well as free-ranging wolves, which are currently recolonizing Germany, may harbor a variety of gastrointestinal parasites. This study investigated endoparasites in captive European gray wolves ( Canis lupus lupus ) using coproscopical methods. Fecal samples were collected monthly between October 2012 and November 2013 from 18 wolf enclosures in 14 German zoological gardens, representing 72 individual wolves. In total, 1,041 fecal samples including 26 bulk samples were analyzed by the sedimentation and flotation method. The most frequently detected egg morphotypes included five nematodes [Ancylostomatidae ( Ancylostoma or Uncinaria spp.), Toxocara canis, Toxascaris leonina, Trichuris vulpis , and Capillaria / Eucoleus spp.], one cestode (Taeniidae) and one trematode ( Alaria alata ). 44.76% of all samples were positive for at least one of these egg morphotypes. Overall, Ancylostomatidae showed the highest frequency (30.84% of all samples), followed by Capillaria/Eucoleus spp. (19.88%), Toxocara canis (5.19%), taeniids (3.75%), Trichuris vulpis and Alaria alata (3.65% each), and Toxascaris leonina (1.25%). As fecal samples were collected from the environment and could not be assigned to individual wolves, sample results were combined per zoo and month. General linear mixed models were employed to analyze the effect of season and management factors on the occurrence of Ancylostomatidae, Capillaria/Eucoleus spp., Toxocara canis and taeniids. No statistically significant effect of season was found, whereas anthelmintic treatment negatively affected Ancylostomatidae egg excretion. Detected parasites and their prevalences are comparable to previous studies on wolf parasitism conducted elsewhere in Europe. As many of the most prevalent helminths are of zoonotic importance, routine anthelmintic treatment of captive wolves should be recommended.

Diphyllidean cestodes from the bigeye houndshark Iago omanensis (Norman) (Carcharhiniformes: Triakidae) in the Gulf of Oman, with the description of Coronocestus ehsanentezarii sp. nov. (Echinobothriidae).

PubMed

Haseli, Mohammad; Azad, Samira

2015-06-01

A new species of Coronocestus Caira, Marques, Jensen, Kuchta and Ivanov, 2013 is described from Iago omanensis (Norman) from the Gulf of Oman. Coronocestus ehsanentezarii sp. nov. differs from C. musteli (Pintner, 1889) Caira, Marques, Jensen, Kuchta and Ivanov, 2013 in that its ovary is H- rather than U-shape. The new species is easily distinguished from C. diamanti (Ivanov and Lipshitz, 2006) Caira, Marques, Jensen, Kuchta and Ivanov, 2013 by the number of spines per column on the cephalic peduncle (24-36 vs 95-118). It differs from C. hormozganiense (Haseli, Malek, Palm and Ivanov, 2012) Caira, Marques, Jensen, Kuchta and Ivanov, 2013 based on a greater number of spines per column on the cephalic peduncle (24-36 vs 18-21). The new species differs from C. notoguidoi (Ivanov 1997) Caira, Marques, Jensen, Kuchta and Ivanov, 2013 in that of its scolex is craspedote rather than acraspedote. Unlike C. coronatum (Robinson 1959) Caira, Marques, Jensen, Kuchta and Ivanov, 2013, C. ehsanentezarii sp. nov. possesses 29-35 rather than 20 apical hooks in each dorso-ventral group. The new species possesses lateral hooklets with two rows (a and b designations) in each cluster. This character had been presented earlier only for Andocadoncum Abbott and Caira, 2014. Furthermore, a new locality record is presented for C. diamanti from Iago omanensis in the Gulf of Oman. Thus, I. omanensis certainly hosts two diphyllidean species simultaneously in the Gulf of Oman. The generic diagnosis of Coronocestus is also revised to include new data.

High-throughput characterization of Echinococcus spp. metacestode miRNomes.

PubMed

Cucher, Marcela; Macchiaroli, Natalia; Kamenetzky, Laura; Maldonado, Lucas; Brehm, Klaus; Rosenzvit, Mara Cecilia

2015-03-01

Echinococcosis is a worldwide zoonosis of great public health concern, considered a neglected disease by the World Health Organisation. The cestode parasites Echinococcus granulosus sensu lato (s. l.) and Echinococcus multilocularis are the main aetiological agents. In the intermediate host, these parasites display particular developmental traits that lead to different patterns of disease progression. In an attempt to understand the causes of these differences, we focused on the analysis of microRNAs (miRNAs), small non-coding regulatory RNAs with major roles in development of animals and plants. In this work, we analysed the small RNA expression pattern of the metacestode, the stage of sanitary relevance, and provide a detailed description of Echinococcus miRNAs. Using high-throughput small RNA sequencing, we believe that we have carried out the first experimental identification of miRNAs in E. multilocularis and have expanded the Echinococcus miRNA catalogue to 38 miRNA genes, including one miRNA only present in E. granulosus s. l. Our findings show that although both species share the top five highest expressed miRNAs, 13 are differentially expressed, which could be related to developmental differences. We also provide evidence that uridylation is the main miRNA processing mechanism in Echinococcus spp. These results provide detailed information on Echinococcus miRNAs, which is the first step in understanding their role in parasite biology and disease establishment and/or progression, and their future potential use as drug or diagnostic targets. Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

REDESCRIPTION OF SCIADOCEPHALUS MEGALODISCUS DIESING, 1850, ONE THE EARLIEST DIVERGING NEOTROPICAL FISH TAPEWORMS (CESTODA: PROTEOCEPHALIDAE).

PubMed

Scholz, Tomáš; de Chambrier, Alain

2018-06-04

The tapeworm Sciadocephalus megalodiscus Diesing, 1850 (Cestoda: Proteocephalidae) is redescribed based on newly collected specimens parasitizing tucunare peacock bass, Cichla monoculus Agassiz, 1831 (Perciformes: Cichlidae), in the Peruvian Amazon. Even though this cestode was redescribed 2 decades ago by Rego et al. (1999), that redescription did not report some of the unique features of this species. The most unusual characteristics of the species are: (i) peculiar formation of the uterus, with fast formation of numerous, tightly packed diverticula protruding ventrally and dorsally, with simultaneous disintegration of the ovary and vitelline follicles in the first pregravid proglottids; (ii) inverted umbrella-shaped scolex with a well-developed apical sucker; (iii) a large-sized, follicular (grape cluster-like) ovary, which occupies most of the central (median) third of proglottids, with the ovarian isthmus situated almost equatorially; (iv) regular alternation of genital pores; (v) a well-developed internal seminal vesicle; and (vi) a small-sized strobila (shorter than 6 mm) consisting of few proglottids (15-20). Preliminary molecular data reveal S. megalodiscus to be most closely related to Cichlidocestus gillesi, the type species of the recently erected Cichlidocestus de Chambrier, Pinacho-Pinacho, Hernández-Orts and Scholz, 2017. Species of both genera parasitize Neotropical cichlids and are unique among all proteocephalids in the shape and position of the ovary. They also share other morphological characteristics unusual among other proteocephalids and thus these two genera can be considered good candidates to be placed in a new, higher-level taxon such as separate subfamily or even family when a new, more natural classification of the Proteocephalidae is proposed.

Zoonotic helminths of urban brown rats (Rattus norvegicus) in the UK: neglected public health considerations?

PubMed

McGarry, J W; Higgins, A; White, N G; Pounder, K C; Hetzel, U

2015-02-01

Urban brown rats (Rattus norvegicus) carry microbial human pathogens but their role as reservoir hosts for helminths of public health importance is less well known. In this study, 42 brown rats trapped on Merseyside were subject to thorough combined helminthological and pathohistological post-mortem examination. Eggs of the rodent-borne zoonotic nematode Calodium hepaticum were initially detected in histological sections of the livers of 9.5% of rats, but overall diagnostic sensitivity increased to 16.6% when entire liver tissue was disrupted and the resulting filtrates were examined for released eggs. In their rat host, mainly trapped inside the dockland, infections with C. hepaticum were associated with a chronic multifocal pyogranulomatous hepatitis with intralesional eggs and peripheral fibrosis. Mean intensity of hepatic C. hepaticum egg infections was 1041 eggs. This is the first report of C. hepaticum in an urban brown rat population in the UK and provides original data for liver egg burdens in this abundant commensal rodent. The zoonotic cestode Rodentolepis nana had a prevalence of infection of 14.3%. Rodent-specific, non-zoonotic helminths found were the spiruroid Mastophorus muris (16.0%) in the stomach, the trichuroid Trichosomoides crassicauda in the urinary bladder (31.0%); the ascarid Heterakis spumosa was the commonest helminth of the large intestine (76.2%). Many millions of brown rats inhabit cities and rural areas of the UK, and the infective stages of the zoonotic worm species, particularly C. hepaticum, are likely to be widely distributed in the environment presenting a threat to public health. © 2014 Blackwell Verlag GmbH.

Associations between body composition and helminths of lesser snow geese during winter and spring migration.

PubMed

Shutler, Dave; Alisauskas, Ray T; Daniel McLaughlin, J

2012-07-01

Costs of parasitism are predicted to be higher with greater parasite intensities and higher inter-parasite competition (diversity). We tested whether greater helminth intensities and diversity were associated with poorer body composition (whole-body fat, protein, mineral and true body mass) in lesser snow geese, Chen caerulescens caerulescens. As part of a larger study on nutritional ecology, 828 wintering or migrating geese were shot between January and May 1983 in 27 different date-locations (samples) during their northward migration through mid-continental North America. A large proportion of overall variation in body composition and parasite communities was among samples, so we analyzed data within each of the 27 samples, controlling for structural body size (the first principal component of 10 body size measurements), sex and the age of geese. There was no compelling evidence that cestodes, trematodes or helminth diversity were associated with variation in body composition but nematodes had several negative associations with fat reserves. However, negative associations between fat reserves and nematodes occurred most often in geese collected between March and May when nematode prevalences and intensities were relatively low. This suggests several possibilities: that the most common nematodes (Heterakis dispar and Trichostrongylus tenuis) were more virulent at this time, that infected individuals had been chronically infected and suffered cumulative nutrient deficits that lasted until late in the spring migration, or that geese became more vulnerable to the effects of parasites at this time of year, possibly because they redirected resources away from immunity toward fat storage in preparation for reproduction. Copyright © 2012 Australian Society for Parasitology Inc. All rights reserved.

Prevalence and impact of gastrointestinal helminths on body weight gain in backyard chickens in subtropical and humid zone of Jammu, India.

PubMed

Katoch, R; Yadav, Anish; Godara, R; Khajuria, J K; Borkataki, S; Sodhi, S S

2012-04-01

Necropsy of gastrointestinal tract of 125 free-range chickens from a subtropical and humid zone of northwestern India revealed four nematode spp. (Ascaridia galli, Heterakis gallinarum, Capillaria spp. and Cheilospirura hamulosa) and four cestode spp. (Raillietina cesticillus, Raillietina echinobothrida, Raillietina tetragona and Amoebotaenia cuneata) The overall prevalence of the helminth parasites was 72.0%. Amongst various helminth species encountered in the region, A. galli emerged out as the most prevalent, followed by H. gallinarum, R. cesticillus and R. echinobothrida. The impact of helminthic infections on body weight gain in growing chickens was investigated. One hundred growing chickens, aged 40 days were randomly assigned to two groups (treated and untreated controls) of 50 birds each. The birds in treated group were given fenbendazole at 7.5 mg per kg body weight in drinking water, while the birds in other group served as untreated controls. At the end of the 90 days of the field trial, the mean body weight gain of untreated controls was 1232.2 ± 7.28 g (13.7 g/day) compared with 1617.6 ± 5.43 g (18.0 g/day) in the treated group. It was associated with a significantly (P < 0.05) higher mean worm burden (32.92 ± 6.12) in untreated controls than the treated group (2.46 ± 1.14). The prevalences of helminthic species and their impact on body weight gain in growing backyard chickens have been discussed.

Effects of parasites and antigenic challenge on metabolic rates and thermoregulation in northern red-backed voles (Myodes rutilus).

PubMed

Novikov, Eugene; Kondratyuk, Ekaterina; Petrovski, Dmitry; Krivopalov, Anton; Moshkin, Mikhail

2015-12-01

Perturbations in host energetics are considered to be an essential pathway for parasite impact on host fitness. However, direct estimations of parasite-induced variations in basal metabolic rates of vertebrate hosts have so far provided contradictory results. The energy requirements of immunity and other vital functions may be compromised in energy-demanding conditions in comparison to comfortable conditions; therefore, in our study performed on the wild red-backed vole, Myodes rutilus, we compared the values of indices that reflect metabolic and thermoregulatory responses to acute cooling in individuals that had been naturally infected by gut helminths or Ixodes persulcatus taiga ticks to individuals with no signs of infestation. To consider the possible effects of an acquired immune response on host energetics, we also injected some of the tested individuals with sheep red blood cells (SRBC). Red-backed voles infected by the nematode Heligmosomum mixtum injected with SRBC showed significantly lower cold-induced maximum oxygen consumption than the saline control. Additionally, individuals infected with H. mixtum showed significantly lower oxygen consumption during the final minute of the 15-min acute cooling period and a significantly greater decline in body temperature than individuals free from helminths. In individuals concurrently infected by H. mixtum and the cestodes Arostrilepis horrida, these indices did not differ from helminth-free individuals. The number of ticks simultaneously parasitizing the voles at the moment of capture correlated positively with their SMR. Our results suggest that even natural parasites produce deleterious effects on host aerobic capacity and thermoregulatory abilities, although the effects of different parasites might not be additive.

Distinct Lineages of Schistocephalus Parasites in Threespine and Ninespine Stickleback Hosts Revealed by DNA Sequence Analysis

PubMed Central

Nishimura, Nicole; Heins, David C.; Andersen, Ryan O.; Barber, Iain; Cresko, William A.

2011-01-01

Parasitic interactions are often part of complex networks of interspecific relationships that have evolved in biological communities. Despite many years of work on the evolution of parasitism, the likelihood that sister taxa of parasites can co-evolve with their hosts to specifically infect two related lineages, even when those hosts occur sympatrically, is still unclear. Furthermore, when these specific interactions occur, the molecular and physiological basis of this specificity is still largely unknown. The presence of these specific parasitic relationships can now be tested using molecular markers such as DNA sequence variation. Here we test for specific parasitic relationships in an emerging host-parasite model, the stickleback-Schistocephalus system. Threespine and ninespine stickleback fish are intermediate hosts for Schistocephalus cestode parasites that are phenotypically very similar and have nearly identical life cycles through plankton, stickleback, and avian hosts. We analyzed over 2000 base pairs of COX1 and NADH1 mitochondrial DNA sequences in 48 Schistocephalus individuals collected from threespine and ninespine stickleback hosts from disparate geographic regions distributed across the Northern Hemisphere. Our data strongly support the presence of two distinct clades of Schistocephalus, each of which exclusively infects either threespine or ninespine stickleback. These clades most likely represent different species that diverged soon after the speciation of their stickleback hosts. In addition, genetic structuring exists among Schistocephalus taken from threespine stickleback hosts from Alaska, Oregon and Wales, although it is much less than the divergence between hosts. Our findings emphasize that biological communities may be even more complex than they first appear, and beg the question of what are the ecological, physiological, and genetic factors that maintain the specificity of the Schistocephalus parasites and their stickleback hosts. PMID:21811623