Sample records for tapeworms parasite phylogeny

  1. Evolution of the trypanorhynch tapeworms: parasite phylogeny supports independent lineages of sharks and rays.

    PubMed

    Olson, Peter D; Caira, Janine N; Jensen, Kirsten; Overstreet, Robin M; Palm, Harry W; Beveridge, Ian

    2010-02-01

    Trypanorhynch tapeworms (Platyhelminthes: Cestoda) are among the most diverse and abundant groups of metazoan parasites of elasmobranchs and are a ubiquitous part of the marine food webs that include these apex predators. Here we present a comprehensive analysis of their phylogeny, character evolution and host associations based on 10years of sampling effort, including representatives of 12 of 15 and 44 of 66 currently recognized trypanorhynch families and genera, respectively. Using a combination of ssrDNA and lsrDNA (Domains 1-3) for 79 and 80 taxa, respectively, we maintain one-to-one correspondence between molecules and morphology by scoring 45 characters from the same specimens used for sequencing, and provide museum vouchers for this material. Host associations are examined through likelihood-based ancestral character state reconstructions (ACSRs) and by estimating dates of divergence using strict and relaxed molecular clock models in a Bayesian context. Maximum parsimony and Bayesian inference analyses of rDNA produced well-resolved and strongly supported trees in which the trypanorhynchs formed two primary lineages and were monophyletic with respect to the diphyllidean outgroup taxa. These lineages showed marked differences in their rates of divergence which in turn resulted in differing support and stability characteristics within the lineages. Mapping of morphological characters onto the tree resulting from combined analysis of rDNA showed most traits to be highly plastic, including some previously considered of key taxonomic importance such as underlying symmetries in tentacular armature. The resulting tree was found to be congruent with the most recent morphologically based superfamily designations in the order, providing support for four proposed superfamilies, but not for the Tentacularioidea and Eutetrarhynchoidea. ACSRs based on the combined analysis of rDNA estimated the original hosts of the two primary parasite lineages to be alternatively

  2. Tapeworm Diphyllobothrium dendriticum (Cestoda)--neglected or emerging human parasite?

    PubMed

    Kuchta, Roman; Brabec, Jan; Kubáčková, Petra; Scholz, Tomáš

    2013-01-01

    A total number of 14 valid species of Diphyllobothrium tapeworms have been described in literature to be capable of causing diphyllobothriosis, with D. latum being the major causative agent of all human infections. However, recent data indicate that some of these infections, especially when diagnosed solely on the basis of morphology, have been identified with this causative agent incorrectly, confusing other Diphyllobothrium species with D. latum. Another widely distributed species, D. dendriticum, has never been considered as a frequent parasite of man, even though it is found commonly throughout arctic and subarctic regions parasitizing piscivorous birds and mammals. Recent cases of Europeans infected with this cestode called into question the actual geographic distribution of this tapeworm, largely ignored by medical parasitologists. On the basis of revision of more than 900 available references and a description and revision of recent European human cases using morphological and molecular (cox1) data supplemented by newly characterized D. dendriticum sequences, we updated the current knowledge of the life-cycle, geographic distribution, epidemiological status, and molecular diagnostics of this emerging causal agent of zoonotic disease of man. The tapeworm D. dendriticum represents an example of a previously neglected, probably underdiagnosed parasite of man with a potential to spread globally. Recent cases of diphyllobothriosis caused by D. dendriticum in Europe (Netherlands, Switzerland and Czech Republic), where the parasite has not been reported previously, point out that causative agents of diphyllobothriosis and other zoonoses can be imported throughout the world. Molecular tools should be used for specific and reliable parasite diagnostics, and also rare or non-native species should be considered. This will considerably help improve our knowledge of the distribution and epidemiology of these human parasites.

  3. Resist Globally, Infect Locally: A Transcontinental Test of Adaptation by Stickleback and Their Tapeworm Parasite.

    PubMed

    Weber, Jesse N; Kalbe, Martin; Shim, Kum Chuan; Erin, Noémie I; Steinel, Natalie C; Ma, Lei; Bolnick, Daniel I

    2017-01-01

    Parasite infections are a product of both ecological processes affecting host-parasite encounter rates and evolutionary dynamics affecting host susceptibility. However, few studies examine natural infection variation from both ecological and evolutionary perspectives. Here, we describe the ecological and evolutionary factors generating variation in infection rates by a tapeworm (Schistocephalus solidus) in a vertebrate host, the threespine stickleback (Gasterosteus aculeatus). To explore ecological aspects of infection, we measured tapeworm prevalence in Canadian stickleback inhabiting two distinct environments: marine and freshwater. Consistent with ecological control of infection, the tapeworm is very rare in marine environments, even though marine fish are highly susceptible. Conversely, commonly infected freshwater stickleback exhibit substantial resistance in controlled laboratory trials, suggesting that high exposure risk overwhelms their recently evolved resistance. We also tested for parasite adaptation to its host by performing transcontinental reciprocal infections, using stickleback and tapeworm populations from Europe and western Canada. More infections occurred in same-continent host-parasite combinations, indicating parasite "local" adaptation, at least on the scale of continents. However, the recently evolved immunity of freshwater hosts applies to both local and foreign parasites. The pattern of adaptation described here is not wholly compatible with either of the common models of host-parasite coevolution (i.e., matching infection or targeted recognition). Instead, we propose a hybrid, eco-evolutionary model to explain the remarkable pattern of global host resistance and local parasite infectivity.

  4. Tapeworm Diphyllobothrium dendriticum (Cestoda)—Neglected or Emerging Human Parasite?

    PubMed Central

    Kuchta, Roman; Brabec, Jan; Kubáčková, Petra; Scholz, Tomáš

    2013-01-01

    Background A total number of 14 valid species of Diphyllobothrium tapeworms have been described in literature to be capable of causing diphyllobothriosis, with D. latum being the major causative agent of all human infections. However, recent data indicate that some of these infections, especially when diagnosed solely on the basis of morphology, have been identified with this causative agent incorrectly, confusing other Diphyllobothrium species with D. latum. Another widely distributed species, D. dendriticum, has never been considered as a frequent parasite of man, even though it is found commonly throughout arctic and subarctic regions parasitizing piscivorous birds and mammals. Recent cases of Europeans infected with this cestode called into question the actual geographic distribution of this tapeworm, largely ignored by medical parasitologists. Methodology and Results On the basis of revision of more than 900 available references and a description and revision of recent European human cases using morphological and molecular (cox1) data supplemented by newly characterized D. dendriticum sequences, we updated the current knowledge of the life-cycle, geographic distribution, epidemiological status, and molecular diagnostics of this emerging causal agent of zoonotic disease of man. Conclusions The tapeworm D. dendriticum represents an example of a previously neglected, probably underdiagnosed parasite of man with a potential to spread globally. Recent cases of diphyllobothriosis caused by D. dendriticum in Europe (Netherlands, Switzerland and Czech Republic), where the parasite has not been reported previously, point out that causative agents of diphyllobothriosis and other zoonoses can be imported throughout the world. Molecular tools should be used for specific and reliable parasite diagnostics, and also rare or non-native species should be considered. This will considerably help improve our knowledge of the distribution and epidemiology of these human parasites

  5. Fish tapeworm infection

    MedlinePlus

    Fish tapeworm infection is an intestinal infection with a parasite found in fish. ... The fish tapeworm ( Diphyllobothrium latum ) is the largest parasite that infects humans. Humans become infected when they eat raw ...

  6. The genomes of four tapeworm species reveal adaptations to parasitism.

    PubMed

    Tsai, Isheng J; Zarowiecki, Magdalena; Holroyd, Nancy; Garciarrubio, Alejandro; Sánchez-Flores, Alejandro; Brooks, Karen L; Tracey, Alan; Bobes, Raúl J; Fragoso, Gladis; Sciutto, Edda; Aslett, Martin; Beasley, Helen; Bennett, Hayley M; Cai, Xuepeng; Camicia, Federico; Clark, Richard; Cucher, Marcela; De Silva, Nishadi; Day, Tim A; Deplazes, Peter; Estrada, Karel; Fernández, Cecilia; Holland, Peter W H; Hou, Junling; Hu, Songnian; Huckvale, Thomas; Hung, Stacy S; Kamenetzky, Laura; Keane, Jacqueline A; Kiss, Ferenc; Koziol, Uriel; Lambert, Olivia; Liu, Kan; Luo, Xuenong; Luo, Yingfeng; Macchiaroli, Natalia; Nichol, Sarah; Paps, Jordi; Parkinson, John; Pouchkina-Stantcheva, Natasha; Riddiford, Nick; Rosenzvit, Mara; Salinas, Gustavo; Wasmuth, James D; Zamanian, Mostafa; Zheng, Yadong; Cai, Jianping; Soberón, Xavier; Olson, Peter D; Laclette, Juan P; Brehm, Klaus; Berriman, Matthew

    2013-04-04

    Tapeworms (Cestoda) cause neglected diseases that can be fatal and are difficult to treat, owing to inefficient drugs. Here we present an analysis of tapeworm genome sequences using the human-infective species Echinococcus multilocularis, E. granulosus, Taenia solium and the laboratory model Hymenolepis microstoma as examples. The 115- to 141-megabase genomes offer insights into the evolution of parasitism. Synteny is maintained with distantly related blood flukes but we find extreme losses of genes and pathways that are ubiquitous in other animals, including 34 homeobox families and several determinants of stem cell fate. Tapeworms have specialized detoxification pathways, metabolism that is finely tuned to rely on nutrients scavenged from their hosts, and species-specific expansions of non-canonical heat shock proteins and families of known antigens. We identify new potential drug targets, including some on which existing pharmaceuticals may act. The genomes provide a rich resource to underpin the development of urgently needed treatments and control.

  7. The genomes of four tapeworm species reveal adaptations to parasitism

    PubMed Central

    Sánchez-Flores, Alejandro; Brooks, Karen L.; Tracey, Alan; Bobes, Raúl J.; Fragoso, Gladis; Sciutto, Edda; Aslett, Martin; Beasley, Helen; Bennett, Hayley M.; Cai, Xuepeng; Camicia, Federico; Clark, Richard; Cucher, Marcela; De Silva, Nishadi; Day, Tim A; Deplazes, Peter; Estrada, Karel; Fernández, Cecilia; Holland, Peter W. H.; Hou, Junling; Hu, Songnian; Huckvale, Thomas; Hung, Stacy S.; Kamenetzky, Laura; Keane, Jacqueline A.; Kiss, Ferenc; Koziol, Uriel; Lambert, Olivia; Liu, Kan; Luo, Xuenong; Luo, Yingfeng; Macchiaroli, Natalia; Nichol, Sarah; Paps, Jordi; Parkinson, John; Pouchkina-Stantcheva, Natasha; Riddiford, Nick; Rosenzvit, Mara; Salinas, Gustavo; Wasmuth, James D.; Zamanian, Mostafa; Zheng, Yadong; Cai, Jianping; Soberón, Xavier; Olson, Peter D.; Laclette, Juan P.; Brehm, Klaus; Berriman, Matthew

    2014-01-01

    Summary Tapeworms cause debilitating neglected diseases that can be deadly and often require surgery due to ineffective drugs. Here we present the first analysis of tapeworm genome sequences using the human-infective species Echinococcus multilocularis, E. granulosus, Taenia solium and the laboratory model Hymenolepis microstoma as examples. The 115-141 megabase genomes offer insights into the evolution of parasitism. Synteny is maintained with distantly related blood flukes but we find extreme losses of genes and pathways ubiquitous in other animals, including 34 homeobox families and several determinants of stem cell fate. Tapeworms have species-specific expansions of non-canonical heat shock proteins and families of known antigens; specialised detoxification pathways, and metabolism finely tuned to rely on nutrients scavenged from their hosts. We identify new potential drug targets, including those on which existing pharmaceuticals may act. The genomes provide a rich resource to underpin the development of urgently needed treatments and control. PMID:23485966

  8. Host and parasite morphology influence congruence between host and parasite phylogenies.

    PubMed

    Sweet, Andrew D; Bush, Sarah E; Gustafsson, Daniel R; Allen, Julie M; DiBlasi, Emily; Skeen, Heather R; Weckstein, Jason D; Johnson, Kevin P

    2018-03-23

    Comparisons of host and parasite phylogenies often show varying degrees of phylogenetic congruence. However, few studies have rigorously explored the factors driving this variation. Multiple factors such as host or parasite morphology may govern the degree of phylogenetic congruence. An ideal analysis for understanding the factors correlated with congruence would focus on a diverse host-parasite system for increased variation and statistical power. In this study, we focused on the Brueelia-complex, a diverse and widespread group of feather lice that primarily parasitise songbirds. We generated a molecular phylogeny of the lice and compared this tree with a phylogeny of their avian hosts. We also tested for the contribution of each host-parasite association to the overall congruence. The two trees overall were significantly congruent, but the contribution of individual associations to this congruence varied. To understand this variation, we developed a novel approach to test whether host, parasite or biogeographic factors were statistically associated with patterns of congruence. Both host plumage dimorphism and parasite ecomorphology were associated with patterns of congruence, whereas host body size, other plumage traits and biogeography were not. Our results lay the framework for future studies to further elucidate how these factors influence the process of host-parasite coevolution. Copyright © 2018 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

  9. The invasive fish tapeworm Atractolytocestus huronensis (Cestoda), a parasite of carp, colonises Africa.

    PubMed

    Scholz, Tomáš; Tavakol, Sareh; Halajian, Ali; Luus-Powell, Wilmien J

    2015-09-01

    Biological invasions represent a serious threat for aquaculture because many of introduced parasites may negatively affect the health state of feral and cultured fish. In the present account, the invasive tapeworm Atractolytocestus huronensis Anthony, 1958 (Cestoda: Caryophyllidea), which was originally described from North America and has been introduced to Europe including the British Isles with its specific host, common carp (Cyprinus carpio L.), is reported from Africa for the first time. Its recent introduction to South Africa, where it was found in four localities where common carp is cultured, is another evidence of insufficient prophylactic measures and inadequate veterinary control during transfers of cultured fish, especially common carp, between continents. Together with the Asian fish tapeworm, Bothriocephalus acheilognathi, A. huronensis is another fish tapeworm with ability to spread throughout the globe as a result of man-made introductions of its fish hosts.

  10. Experimental parasite community ecology: intraspecific variation in a large tapeworm affects community assembly.

    PubMed

    Benesh, Daniel P; Kalbe, Martin

    2016-07-01

    Non-random species associations occur in naturally sampled parasite communities. The processes resulting in predictable community structure (e.g. particular host behaviours, cross-immunity, interspecific competition) could be affected by traits that vary within a parasite species, like growth or antigenicity. We experimentally infected three-spined sticklebacks with a large tapeworm (Schistocephalus solidus) that impacts the energy needs, foraging behaviour and immune reactions of its host. The tapeworms came from two populations, characterized by high or low growth in sticklebacks. Our goal was to evaluate how this parasite, and variation in its growth, affects the acquisition of other parasites. Fish infected with S. solidus were placed into cages in a lake to expose them to the natural parasite community. We also performed a laboratory experiment in which infected fish were exposed to a fixed dose of a common trematode parasite. In the field experiment, infection with S. solidus affected the abundance of four parasite species, relative to controls. For two of the four species, changes occurred only in fish harbouring the high-growth S. solidus; one species increased in abundance and the other decreased. These changes did not appear to be directly linked to S. solidus growth though. The parasite exhibiting elevated abundance was the same trematode used in the laboratory infection. In that experiment, we found a similar infection pattern, suggesting that S. solidus affects the physiological susceptibility of fish to this trematode. Associations between S. solidus and other parasites occur and vary in direction. However, some of these associations were contingent on the S. solidus population, suggesting that intraspecific variability can affect the assembly of parasite communities. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  11. 9 CFR 311.25 - Parasites not transmissible to man; tapeworm cysts in sheep; hydatid cysts; flukes; gid bladder...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Parasites not transmissible to man... DISEASED OR OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.25 Parasites not transmissible to man; tapeworm... man, the following general rules shall govern except as otherwise provided in this section: If the...

  12. 9 CFR 311.25 - Parasites not transmissible to man; tapeworm cysts in sheep; hydatid cysts; flukes; gid bladder...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Parasites not transmissible to man... DISEASED OR OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.25 Parasites not transmissible to man; tapeworm... man, the following general rules shall govern except as otherwise provided in this section: If the...

  13. 9 CFR 311.25 - Parasites not transmissible to man; tapeworm cysts in sheep; hydatid cysts; flukes; gid bladder...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Parasites not transmissible to man... DISEASED OR OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.25 Parasites not transmissible to man; tapeworm... man, the following general rules shall govern except as otherwise provided in this section: If the...

  14. 9 CFR 311.25 - Parasites not transmissible to man; tapeworm cysts in sheep; hydatid cysts; flukes; gid bladder...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Parasites not transmissible to man... DISEASED OR OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.25 Parasites not transmissible to man; tapeworm... man, the following general rules shall govern except as otherwise provided in this section: If the...

  15. Fish tapeworm Khawia sinensis: an indicator of environmental microcystins?

    PubMed

    Palikova, Miroslava; Adamovsky, Ondrej; Blaha, Ludek; Mares, Jan; Kopp, Radovan; Navratil, Stanislav; Cutakova, Zdenka; Soukupova, Zdenka; Pikula, Jiri

    2013-01-01

    Parasites have recently been recognized as accumulation indicators that take up and bio-concentrate substances from environmental pollution. Interestingly, helminths of fish are known to accumulate metals from the ambient environment and to contain several orders of magnitude higher concentrations than hosts. While the majority of reports mention inorganic toxin accumulation in parasites, studies concerning effects of organic pollution are infrequent and little is known about the potential of parasites to bio-accumulate microcystins. The parasite-host system of tapeworm Khawia sinensis and common carp (Cyprinus carpio) was used to address this issue. Both the tapeworms and livers were dissected from experimental carps orally exposed to cyanobacterial biomass for 20 days. The total dose of microcystins amounted to 27 mg/kg of feed, i.e., 0.4 mg/kg of fish mass a day. Microcystin concentrations in tapeworms and carp liver tissues were measured using the LC-MS/MS method. Considering the three measured microcystin variants LR, YR and RR, only MC-RR was detected and its concentrations in tapeworms and carp liver tissue amounted to 5.78±3.78 ng/g and 2.11±0.74 ng/g fresh weight (p<0.05), respectively. Here we show accumulation of microcystin MC-RR in the tapeworm Khawia sinensis, a parasite of common carp (Cyprinus carpio). As this is the first report addressing this issue, further studies will be necessary to examine this specific parasite-host system.

  16. Fitness impacts of tapeworm parasitism on wild gelada monkeys at Guassa, Ethiopia.

    PubMed

    Nguyen, Nga; Fashing, Peter J; Boyd, Derek A; Barry, Tyler S; Burke, Ryan J; Goodale, C Barret; Jones, Sorrel C Z; Kerby, Jeffrey T; Kellogg, Bryce S; Lee, Laura M; Miller, Carrie M; Nurmi, Niina O; Ramsay, Malcolm S; Reynolds, Jason D; Stewart, Kathrine M; Turner, Taylor J; Venkataraman, Vivek V; Knauf, Yvonne; Roos, Christian; Knauf, Sascha

    2015-05-01

    Parasitism is expected to impact host morbidity or mortality, although the fitness costs of parasitism have rarely been quantified for wildlife hosts. Tapeworms in the genus Taenia exploit a variety of vertebrates, including livestock, humans, and geladas (Theropithecus gelada), monkeys endemic to the alpine grasslands of Ethiopia. Despite Taenia's adverse societal and economic impacts, we know little about the prevalence of disease associated with Taenia infection in wildlife or the impacts of this disease on host health, mortality and reproduction. We monitored geladas at Guassa, Ethiopia over a continuous 6½ year period for external evidence (cysts or coenuri) of Taenia-associated disease (coenurosis) and evaluated the impact of coenurosis on host survival and reproduction. We also identified (through genetic and histological analyses) the tapeworms causing coenurosis in wild geladas at Guassa as Taenia serialis. Nearly 1/3 of adult geladas at Guassa possessed ≥1 coenurus at some point in the study. Coenurosis adversely impacted gelada survival and reproduction at Guassa and this impact spanned two generations: adults with coenuri suffered higher mortality than members of their sex without coenuri and offspring of females with coenuri also suffered higher mortality. Coenurosis also negatively affected adult reproduction, lengthening interbirth intervals and reducing the likelihood that males successfully assumed reproductive control over units of females. Our study provides the first empirical evidence that coenurosis increases mortality and reduces fertility in wild nonhuman primate hosts. Our research highlights the value of longitudinal monitoring of individually recognized animals in natural populations for advancing knowledge of parasite-host evolutionary dynamics and offering clues to the etiology and control of infectious disease. © 2015 Wiley Periodicals, Inc.

  17. Phylogeny, host-parasite relationship and zoogeography

    PubMed Central

    1999-01-01

    Phylogeny is the evolutionary history of a group or the lineage of organisms and is reconstructed based on morphological, molecular and other characteristics. The genealogical relationship of a group of taxa is often expressed as a phylogenetic tree. The difficulty in categorizing the phylogeny is mainly due to the existence of frequent homoplasies that deceive observers. At the present time, cladistic analysis is believed to be one of the most effective methods of reconstructing a phylogenetic tree. Excellent computer program software for phylogenetic analysis is available. As an example, cladistic analysis was applied for nematode genera of the family Acuariidae, and the phylogenetic tree formed was compared with the system used currently. Nematodes in the genera Nippostrongylus and Heligmonoides were also analyzed, and the validity of the reconstructed phylogenetic trees was observed from a zoogeographical point of view. Some of the theories of parasite evolution were briefly reviewed as well. Coevolution of parasites and humans was discussed with special reference to the evolutionary relationship between Enterobius and primates. PMID:10634036

  18. 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.

  19. 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.

  20. 9 CFR 311.25 - Parasites not transmissible to man; tapeworm cysts in sheep; hydatid cysts; flukes; gid bladder...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Parasites not transmissible to man; tapeworm cysts in sheep; hydatid cysts; flukes; gid bladder-worms. 311.25 Section 311.25 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS...

  1. Checklist of tapeworms (Platyhelminthes, Cestoda) of vertebrates in Finland

    PubMed Central

    Haukisalmi, Voitto

    2015-01-01

    Abstract A checklist of tapeworms (Cestoda) of vertebrates (fishes, birds and mammals) in Finland is presented, based on published observations, specimens deposited in the collections of the Finnish Museum of Natural History (Helsinki) and the Zoological Museum of the University of Turku, and additional specimens identified by the present author. The checklist includes 170 tapeworm species from 151 host species, comprising 447 parasite species/host species combinations. Thirty of the tapeworm species and 96 of the parasite/host species combinations have not been previously reported from Finland. The total number of tapeworm species in Finland (170 spp.) is significantly lower than the corresponding figure for the Iberian Peninsula (257 spp.), Slovakia (225 spp.) and Poland (279 spp.). The difference between Finland and the other three regions is particularly pronounced for anseriform, podicipediform, charadriiform and passeriform birds, reflecting inadequate and/or biased sampling of these birds in Finland. It is predicted that there are actually ca. 270 species of tapeworms in Finland, assuming that true number of bird tapeworms in Finland corresponds to that in other European countries with more comprehensive knowledge of the local tapeworm fauna. The other main pattern emerging from the present data is the seemingly unexplained absence in (northern) Fennoscandia of several mammalian tapeworms that otherwise have extensive distributions in the Holarctic region or in Eurasia, including the northern regions. Previously unknown type specimens, that is, the holotype of Bothrimonus nylandicus Schneider, 1902 (a junior synonym of Diplocotyle olrikii Krabbe, 1874) (MZH 127096) and the syntypes of Caryophyllaeides fennica (Schneider, 1902) (MZH 127097) were located in the collections of the Finnish Museum of Natural History. PMID:26668540

  2. Endangered fish threatened by Asian fish tapeworm

    USGS Publications Warehouse

    Cole, Rebecca A.

    2004-01-01

    The Asian fish tapeworm, an exotic parasite, has invaded the endangered humpback chub (Gila cypha) population from the Colorado and Little Colorado Rivers in Grand Canyon, Arizona. This parasite causes disease and death in carp in aquaculture settings and may retard growth in hatchery-reared roundtail chub (Gila robusta). Other consequences include destruction and dysfunction of the intestinal lining and adverse changes to certain blood parameters. Introduced into the U.S. in the 1970s with imported grass carp (Ctenopharyngodon idella), the Asian fish tapeworm (Bothriocephalus acheilognathi) was discovered in the Little Colorado River (LCR) by 1990. The LCR is the main tributary to the Colorado River in Grand Canyon and is an important spawning area for humpback chub.

  3. Asian fish tapeworm Bothriocephalus acheilognathi in the desert southwestern United States.

    PubMed

    Archdeacon, Thomas P; Iles, Alison; Kline, S Jason; Bonar, Scott A

    2010-12-01

    The Asian fish tapeworm Bothriocephalus acheilognathi (Cestoda: Bothriocephalidea) is an introduced fish parasite in the southwestern United States and is often considered a serious threat to native desert fishes. Determining the geographic distribution of nonnative fish parasites is important for recovery efforts of native fishes. We examined 1,140 individuals belonging to nine fish species from southwestern U.S. streams and springs between January 2005 and April 2007. The Asian fish tapeworm was present in the Gila River, Salt River, Verde River, San Pedro River, Aravaipa Creek, and Fossil Creek, Arizona, and in Lake Tuendae at Zzyzx Springs and Afton Canyon of the Mojave River, California. Overall prevalence of the Asian fish tapeworm in Arizona fish populations was 19% (range = 0-100%) and varied by location, time, and fish species. In California, the prevalence, abundance, and intensity of the Asian fish tapeworm in Mohave tui chub Gila bicolor mohavensis were higher during warmer months than during cooler months. Three new definitive host species--Yaqui chub G. purpurea, headwater chub G. nigra, and longfin dace agosia chrysogaster--were identified. Widespread occurrence of the Asian fish tapeworm in southwestern U.S. waters suggests that the lack of detection in other systems where nonnative fishes occur is due to a lack of effort as opposed to true absence of the parasite. To limit further spread of diseases to small, isolated systems, we recommend treatment for both endo- and exoparasites when management actions include translocation of fishes.

  4. [Efficacy of praziquantel injectable solution against feline and canine tapeworms.].

    PubMed

    Tüzer, Erkut; Bilgin, Zahide; Oter, Kerem; Erçin, Süleyman; Tinar, Recep

    2010-01-01

    Praziquantel, which has been used in the treatment and control of canine and feline tapeworm infections for about 35 years, has not been tested against these parasites for a long period in Turkey. This study was performed to evaluate the current efficacy of praziquantel against dog and cat tapeworms. Praziquantel injectable solution was administered to 26 dogs (14 of them were infected with Dipylidium caninum, 8 with Taenia spp and 2 with Echinococcus granulosus, 2 with both Dipylidium caninum and Taenia spp) and 2 cats (infected with Joyeuxiella pasqualei) subcutaneously at a dose of 0.1 ml/kg (5.68 mg active ingredient/kg). After treatment, animals were put in individual cages and their feces were taken daily for examination. Feces were examined macroscopically for tapeworm segments and scolexes and microscopically for tapeworm eggs by Fülleborn's flotation and Teleman's sedimentation (for fatty stools). To confirm results of analysis the examinations after treatment were repeated until two subsequent fecal analyses were negative. The parasites disappeared from the feces of all infected animals in 2 or 3 days after the treatment and the drug was found to be 100% effective against both dog and cat tapeworms. No adverse reactions were observed in both dogs and cats treated.

  5. A confocal microscopy-based atlas of tissue architecture in the tapeworm Hymenolepis diminuta.

    PubMed

    Rozario, Tania; Newmark, Phillip A

    2015-11-01

    Tapeworms are pervasive and globally distributed parasites that infect millions of humans and livestock every year, and are the causative agents of two of the 17 neglected tropical diseases prioritized by the World Health Organization. Studies of tapeworm biology and pathology are often encumbered by the complex life cycles of disease-relevant tapeworm species that infect hosts such as foxes, dogs, cattle, pigs, and humans. Thus, studies of laboratory models can help overcome the practical, ethical, and cost-related difficulties faced by tapeworm parasitologists. The rat intestinal tapeworm Hymenolepis diminuta is easily reared in the laboratory and has the potential to enable modern molecular-based experiments that will greatly contribute to our understanding of multiple aspects of tapeworm biology, such as growth and reproduction. As part of our efforts to develop molecular tools for experiments on H. diminuta, we have characterized a battery of lectins, antibodies, and common stains that label different tapeworm tissues and organ structures. Using confocal microscopy, we have assembled an "atlas" of H. diminuta organ architecture that will be a useful resource for helminthologists. The methodologies we describe will facilitate characterization of loss-of-function perturbations using H. diminuta. This toolkit will enable a greater understanding of fundamental tapeworm biology that may elucidate new therapeutic targets toward the eradication of these parasites. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  6. A large 28S rDNA-based phylogeny confirms the limitations of established morphological characters for classification of proteocephalidean tapeworms (Platyhelminthes, Cestoda)

    PubMed Central

    de Chambrier, Alain; Waeschenbach, Andrea; Fisseha, Makda; Scholz, Tomáš; Mariaux, Jean

    2015-01-01

    Abstract Proteocephalidean tapeworms form a diverse group of parasites currently known from 315 valid species. Most of the diversity of adult proteocephalideans can be found in freshwater fishes (predominantly catfishes), a large proportion infects reptiles, but only a few infect amphibians, and a single species has been found to parasitize possums. Although they have a cosmopolitan distribution, a large proportion of taxa are exclusively found in South America. We analyzed the largest proteocephalidean cestode molecular dataset to date comprising more than 100 species (30 new), including representatives from 54 genera (80%) and all subfamilies, thus significantly improving upon previous works to develop a molecular phylogeny for the group. The Old World origin of proteocephalideans is confirmed, with their more recent expansion in South America. The earliest diverging lineages are composed of Acanthotaeniinae and Gangesiinae but most of the presently recognized subfamilies (and genera) appear not to be monophyletic; a deep systematic reorganization of the order is thus needed and the present subfamilial system should be abandoned. The main characters on which the classical systematics of the group has been built, such as scolex morphology or relative position of genital organs in relation to the longitudinal musculature, are of limited value, as demonstrated by the very weak support for morphologically-defined subfamilies. However, new characters, such as the pattern of uterus development, relative ovary size, and egg structure have been identified, which may be useful in defining phylogenetically well-supported subgroups. A strongly supported lineage infecting various snakes from a wide geographical distribution was found. Although several improvements over previous works regarding phylogenetic resolution and taxon coverage were achieved in this study, the major polytomy in our tree, composed largely of siluriform parasites from the Neotropics, remained

  7. Complete life cycle of the canid tapeworm, Echinococcus multilocularis, in laboratory rodents.

    PubMed

    Kamiya, M; Sato, H

    1990-12-01

    Mongolian gerbils, Meriones unguiculatus, when treated at intervals of 2-6 days with prednisolone tertiary butyl acetate, sustained infection with adult Echinococcus multilocularis in the small intestine, with the tapeworm exhibiting normal strobilation and egg production as in the natural canid host. Host age is critical for the survival of the tapeworm in normal gerbils; parasites survive for only 2 days in 20-wk-old animals, 4 days in 4-wk-old animals, but at least 7 days in 3-wk-old animals. The host age dependence in parasite recovery between days 28-37 postinfection was not affected by treatment from around the day of infection. Starting the treatment before infection (on day -17 relative to infection) remarkably improved the tapeworm's survival within the intestine of older animals. Eggs produced in this rodent model system 28 days postinfection were infective to rodents such as Mongolian gerbils and gray red-backed voles, Clethrionomys rufocanus bedfordiae, by oral or intraperitoneal inoculation. The E. multilocularis/Mongolian gerbil system can replace the natural canid hosts as a new way to obtain infective eggs and to analyze host-parasite interactions. The development of an alternative definitive host for zoonotic tapeworms may accelerate experimentation in this field.

  8. Definitive Hosts of Versteria Tapeworms (Cestoda: Taeniidae) Causing Fatal Infection in North America.

    PubMed

    Lee, Laura M; Wallace, Roberta S; Clyde, Victoria L; Gendron-Fitzpatrick, Annette; Sibley, Samuel D; Stuchin, Margot; Lauck, Michael; O'Connor, David H; Nakao, Minoru; Lavikainen, Antti; Hoberg, Eric P; Goldberg, Tony L

    2016-04-01

    We previously reported fatal infection of a captive Bornean orangutan with metacestodes of a novel taeniid tapeworm, Versteria sp. New data implicate mustelids as definitive hosts of these tapeworms in North America. At least 2 parasite genetic lineages circulate in North America, representing separate introductions from Eurasia.

  9. Definitive Hosts of Versteria Tapeworms (Cestoda: Taeniidae) Causing Fatal Infection in North America

    PubMed Central

    Lee, Laura M.; Wallace, Roberta S.; Clyde, Victoria L.; Gendron-Fitzpatrick, Annette; Sibley, Samuel D.; Stuchin, Margot; Lauck, Michael; O’Connor, David H.; Nakao, Minoru; Lavikainen, Antti; Hoberg, Eric P.

    2016-01-01

    We previously reported fatal infection of a captive Bornean orangutan with metacestodes of a novel taeniid tapeworm, Versteria sp. New data implicate mustelids as definitive hosts of these tapeworms in North America. At least 2 parasite genetic lineages circulate in North America, representing separate introductions from Eurasia. PMID:26983004

  10. Tour around the globe: The case of invasive tapeworm Atractolytocestus huronensis (Cestoda: Caryophyllidea), a parasite of common carp.

    PubMed

    Bazsalovicsová, Eva; Králová-Hromadová, Ivica; Xi, Bing-Wen; Štefka, Jan

    2018-02-24

    The monozoic tapeworm Atractolytocestus huronensis Anthony, 1958 (Cestoda: Caryophyllidea), an intestinal parasite of the common carp, is characterized by its invasive character and potential to colonize new territories. It was initially described from North America and has also been found in several European countries. The most recent findings of A. huronensis originated from China and South Africa; however, no data on genetic relationships of these populations were available. The current study provides the first molecular characterisation of A. huronensis from South Africa and China using a partial sequence of mitochondrial cytochrome c oxidase subunit 1 (cox1) and a complete ribosomal ITS2 spacer. Ribosomal and mitochondrial data were applied for phylogenetic analyses in order to assess the genetic interrelationships among global A. huronensis populations. Divergent intragenomic copies of ribosomal ITS2 were detected in all analysed specimens; the structure and frequency of the ITS2 variants of tapeworms from China and South Africa corresponded with the data on ITS2 paralogues observed previously in A. huronensis from Slovakia, the United States and the United Kingdom. The phylogenetic analysis of cox1 indicated that A. huronensis exist in two slightly differentiated clusters; one cluster was supported by all phylogenetic approaches (NJ, ML, BI) and was represented by samples from China, the USA and the UK. A second cluster was represented by tapeworms from continental Europe (Slovakia, Hungary, Romania, Croatia) and South Africa. Haplotype network analysis revealed that the highest population diversity occurs in China. The results provide useful pilot information about the interrelationships of A. huronensis on four continents and indicate that China, or the eastern Palaearctic, served as the original source population for the global expansion of this invasive tapeworm. Data on the origin and distribution of the common carp, the only specific host of A

  11. An experimental approach to the immuno-modulatory basis of host-parasite local adaptation in tapeworm-infected sticklebacks.

    PubMed

    Hamley, Madeleine; Franke, Frederik; Kurtz, Joachim; Scharsack, Jörn Peter

    2017-09-01

    The evolutionary arms race of hosts and parasites often results in adaptations, which may differ between populations. Investigation of such local adaptation becomes increasingly important to understand dynamics of host-parasite interactions and co-evolution. To this end we performed an infection experiment involving pairs of three-spined sticklebacks and their tapeworm parasite Schistocephalus solidus from three geographically separated origins (Germany, Spain and Iceland) in a fully-crossed design for sympatric and allopatric host/parasite combinations. We hypothesized that local adaptation of the hosts results in differences in parasite resistance with variation in parasite infection rates and leukocyte activation, whereas parasites from different origins might differ in virulence reflected in host exploitation rates (parasite indices) and S. solidus excretory-secretory products (SsESP) involved in immune manipulation. In our experimental infections, sticklebacks from Iceland were more resistant to S. solidus infection compared to Spanish and German sticklebacks. Higher resistance of Icelandic sticklebacks seemed to depend on adaptive immunity, whereas sticklebacks of German origin, which were more heavily afflicted by S. solidus, showed elevated activity of innate immune traits. German S. solidus were less successful in infecting and exploiting allopatric hosts compared to their Icelandic and Spanish conspecifics. Nevertheless, exclusively SsESP from German S. solidus triggered significant in vitro responses of leukocytes from naïve sticklebacks. Interestingly, parasite indices were almost identical across the sympatric combinations. Differences in host resistance and parasite virulence between the origins were most evident in allopatric combinations and were consistent within origin; i.e. Icelandic sticklebacks were more resistant and their S. solidus were more virulent in all allopatric combinations, whereas German sticklebacks were less resistant and

  12. Taxonomy, phylogeny and molecular epidemiology of Echinococcus multilocularis: From fundamental knowledge to health ecology.

    PubMed

    Knapp, Jenny; Gottstein, Bruno; Saarma, Urmas; Millon, Laurence

    2015-10-30

    Alveolar echinococcosis, caused by the tapeworm Echinococcus multilocularis, is one of the most severe parasitic diseases in humans and represents one of the 17 neglected diseases prioritised by the World Health Organisation (WHO) in 2012. Considering the major medical and veterinary importance of this parasite, the phylogeny of the genus Echinococcus is of considerable importance; yet, despite numerous efforts with both mitochondrial and nuclear data, it has remained unresolved. The genus is clearly complex, and this is one of the reasons for the incomplete understanding of its taxonomy. Although taxonomic studies have recognised E. multilocularis as a separate entity from the Echinococcus granulosus complex and other members of the genus, it would be premature to draw firm conclusions about the taxonomy of the genus before the phylogeny of the whole genus is fully resolved. The recent sequencing of E. multilocularis and E. granulosus genomes opens new possibilities for performing in-depth phylogenetic analyses. In addition, whole genome data provide the possibility of inferring phylogenies based on a large number of functional genes, i.e. genes that trace the evolutionary history of adaptation in E. multilocularis and other members of the genus. Moreover, genomic data open new avenues for studying the molecular epidemiology of E. multilocularis: genotyping studies with larger panels of genetic markers allow the genetic diversity and spatial dynamics of parasites to be evaluated with greater precision. There is an urgent need for international coordination of genotyping of E. multilocularis isolates from animals and human patients. This could be fundamental for a better understanding of the transmission of alveolar echinococcosis and for designing efficient healthcare strategies. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Phylogenetic relationships within Echinococcus and Taenia tapeworms (Cestoda: Taeniidae): an inference from nuclear protein-coding genes.

    PubMed

    Knapp, Jenny; Nakao, Minoru; Yanagida, Tetsuya; Okamoto, Munehiro; Saarma, Urmas; Lavikainen, Antti; Ito, Akira

    2011-12-01

    The family Taeniidae of tapeworms is composed of two genera, Echinococcus and Taenia, which obligately parasitize mammals including humans. Inferring phylogeny via molecular markers is the only way to trace back their evolutionary histories. However, molecular dating approaches are lacking so far. Here we established new markers from nuclear protein-coding genes for RNA polymerase II second largest subunit (rpb2), phosphoenolpyruvate carboxykinase (pepck) and DNA polymerase delta (pold). Bayesian inference and maximum likelihood analyses of the concatenated gene sequences allowed us to reconstruct phylogenetic trees for taeniid parasites. The tree topologies clearly demonstrated that Taenia is paraphyletic and that the clade of Echinococcus oligarthrus and Echinococcusvogeli is sister to all other members of Echinococcus. Both species are endemic in Central and South America, and their definitive hosts originated from carnivores that immigrated from North America after the formation of the Panamanian land bridge about 3 million years ago (Ma). A time-calibrated phylogeny was estimated by a Bayesian relaxed-clock method based on the assumption that the most recent common ancestor of E. oligarthrus and E. vogeli existed during the late Pliocene (3.0 Ma). The results suggest that a clade of Taenia including human-pathogenic species diversified primarily in the late Miocene (11.2 Ma), whereas Echinococcus started to diversify later, in the end of the Miocene (5.8 Ma). Close genetic relationships among the members of Echinococcus imply that the genus is a young group in which speciation and global radiation occurred rapidly. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Histopathological and ultrastructural studies of the tapeworm Monobothrium wageneri (Caryophyllidea) in the intestinal tract of tench Tinca tinca.

    PubMed

    Williams, C F; Poddubnaya, L G; Scholz, T; Turnbull, J F; Ferguson, H W

    2011-12-06

    Monobothrium wageneri is a monozoic caryophyllidean tapeworm of tench Tinca tinca. The pathological changes caused by this parasite within the intestinal tract of wild tench are described for the first time. Parasites were found attached to the anterior third of the intestine in tight clusters comprising up to 109 tapeworms. Infection was associated with the formation of raised inflammatory swellings surrounding the parasites. This host response, combined with the deep penetration of the scolex into the gut wall, formed a very firm seat of parasite attachment. Histopathological changes were characterised by a pronounced fibrogranulomatous lesion that extended through all layers of the intestine. This was accompanied by haemorrhage, oedema, necrosis and degeneration of the muscularis. A marked eosinophilic interface layer between the scolex of the tapeworm and gut wall indicated intimate host-parasite contact. Ultrastructural examinations revealed coniform spinitriches covering the neck and lateral sides of the scolex and capilliform filitriches present on the apical end of the scolex. Numerous glandular cytons (tegumental glands) were recorded throughout the scolex tegument. Large numbers of secretory granules discharged from the glands through a network of processes onto the scolex surface were consistent with distancing the cellular responses of the host. Observations of severe inflammatory lesions, partial intestinal occlusion and the potential for intestinal perforation represent important pathological changes that are consistent with loss of normal gut function. The lesions associated with the attachment of M. wageneri are more severe than those recorded for any other tapeworm of British freshwater fish.

  15. Genetics of the pig tapeworm in Madagascar reveal a history of human dispersal and colonization

    USDA-ARS?s Scientific Manuscript database

    An intricate history of human dispersal and geographic colonization has strongly affected the distribution of obligate parasites circulating among people. Among these parasites, the pig tapeworm Taenia solium occurs throughout the world as the causative agent of cysticercosis, one of the most serio...

  16. [Tapeworm Oochoristica tuberculata (Rudolphi, 1819)--parasite of the lizard Eremias argus Peters, 1869 in Zabaikalie].

    PubMed

    Dugarov, Zh N; Baldanova, D R; Khamnueva, T R

    2012-01-01

    Morphological characteristics of the tapeworm Oochoristica tuberculata from the lizard Eremias argus is given from the northern border of the host areal. The complexes of most stable and most variable characters of this tapeworm are determined. The list of hosts is given for Oochoristica tuberculata.

  17. An investigation of the co-evolutionary relationships between onchobothriid tapeworms and their elasmobranch hosts.

    PubMed

    Caira, J N; Jensen, K

    2001-07-01

    There is general consensus that the living elasmobranchs comprise a monophyletic taxon. There is evidence that, among tetraphyllidean tapeworms, the approximately 201 hooked species (Onchobothriidae) may also comprise a monophyletic group. Determinations of host specificity are contingent upon correct specific identifications. Since 1960, over 200 new elasmobranch species and over 100 new onchobothriid species have been described. Some confidence can be placed in host and parasite identifications of recent studies, but specific identifications provided in older literature in many cases are suspect. There is some consensus among published works on the phylogenetic relationships among elasmobranchs. Phylogenetic relationships among onchobothriids remain largely unresolved. Elasmobranchs have been poorly sampled for onchobothriids; records exist for approximately 20% of the 911 species and approximately 44% of the 170 elasmobranch genera. Onchobothriids are remarkably host specific, exhibiting essentially oioxenous specificity for their definitive hosts. Multiple onchobothriid species commonly parasitise the same host species; in some cases these are congeners, in other cases these are members of two different onchobothriid genera. There is substantial incongruence between available host and parasite phylogenies. For example, Acanthobothrium is by far the most ubiquitous onchobothriid genus, parasitising almost all orders of elasmobranchs known to host onchobothriids, yet, there is no evidence of major clades of Acanthobothrium corresponding to postulated major subgroupings of elasmobranchs (e.g. Galea and Squalea or sharks and rays). Potamotrygonocestus appears to be among the most basal onchobothriid groups, yet it parasitises one of the most derived elasmobranch groups (the freshwater stingray genus Potamotrygon). It appears that congeners parasitising the same host species are not necessarily each other's closest relatives. At this point the preliminary and

  18. Tapeworm Infection

    MedlinePlus

    ... adult tapeworm consists of a head, neck and chain of segments called proglottids. When you have an ... blockage. If tapeworms grow large enough, they can block your appendix, leading to infection (appendicitis); your bile ...

  19. Spatial relationship between Taenia solium tapeworm carriers and necropsy cyst burden in pigs.

    PubMed

    Pray, Ian W; Ayvar, Viterbo; Gamboa, Ricardo; Muro, Claudio; Moyano, Luz M; Benavides, Victor; Flecker, Robert H; Garcia, Hector H; O'Neal, Seth E

    2017-04-01

    Taenia solium, a parasite that affects humans and pigs, is the leading cause of preventable epilepsy in the developing world. Geographic hotspots of pigs testing positive for serologic markers of T. solium exposure have been observed surrounding the locations of human tapeworm carriers. This clustered pattern of seropositivity in endemic areas formed the basis for geographically targeted control interventions, which have been effective at reducing transmission. In this study, we further explore the spatial relationship between human tapeworm carriers and infected pigs using necroscopic examination as a quantitative gold-standard diagnostic to detect viable T. solium cyst infection in pigs. We performed necroscopic examinations on pigs from 7 villages in northern Peru to determine the number of viable T. solium cysts in each pig. Participating humans in the study villages were tested for T. solium tapeworm infection (i.e., taeniasis) with an ELISA coproantigen assay, and the distances from each pig to its nearest human tapeworm carrier were calculated. We assessed the relationship between proximity to a tapeworm carrier and the prevalence of light, moderate, and heavy cyst burden in pigs. The prevalence of pig infection was greatest within 50 meters of a tapeworm carrier and decreased monotonically as distance increased. Pigs living less than 50 meters from a human tapeworm carrier were 4.6 times more likely to be infected with at least one cyst than more distant pigs. Heavier cyst burdens, however, were not more strongly associated with proximity to tapeworm carriers than light cyst burdens. Our study shows that human tapeworm carriers and pigs with viable T. solium cyst infection are geographically correlated in endemic areas. This finding supports control strategies that treat humans and pigs based on their proximity to other infected individuals. We did not, however, find sufficient evidence that heavier cyst burdens in pigs would serve as improved targets for

  20. Tapeworms (Cestoda: Caryophyllidea), parasites of Clarias batrachus (Pisces: Siluriformes) in the Indomalayan region.

    PubMed

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

    2011-06-01

    Revision of monozoic cestodes (Caryophyllidea) parasitic in commercially important walking catfish Clarias batrachus (L.) in tropical Asia (Indomalayan zoogeographical region) was carried out, based on the evaluation of newly collected material from India, Indonesia, and Thailand, as well as a study of type specimens. Instead of the 59 nominal taxa of 15 genera from 3 caryophyllidean families previously described, only 8 species of the Lytocestidae are considered to be valid: Bovienia indica (Niyogi, Gupta and Agarwal, 1982) n. comb.; Bovienia raipurensis (Satpute and Agarwal, 1980) Mackiewicz, 1994; Bovienia serialis (Bovien, 1926) Fuhrmann, 1931; Djombangia penetrans Bovien, 1926; Lucknowia microcephala (Bovien, 1926) n. comb.; Lytocestus indicus (Moghe, 1925) Woodland 1926; Pseudocaryophyllaeus ritai Gupta and Singh, 1983; and Pseudocaryophyllaeus tenuicollis (Bovien, 1926) n. comb. All valid species are redescribed and SEM photomicrographs of their scolices and photomicrographs of their eggs are provided for the first time. Crescentovitus Murhar, 1963, Heeradevina Srivastav and Khare, 2005, Pseudobatrachus Pathak and Srivastav, 2005, Pseudobilobulata Srivastav and Lohia, 2002, Pseudoclariasis Pathak, 2002, and Pseudoinverta Pathak, 2002 are invalidated and 50 nominal species are newly synonymized, including 4 species described from other fish hosts. Taxonomic status of the remaining caryophyllidean taxa reported from C. batrachus (at least 6 taxa) could not be clarified because of the unavailability of their original descriptions. A key to identification of caryophyllidean tapeworms parasitic in C. batrachus is provided. To avoid current inflation of descriptions of invalid taxa, researchers are strongly encouraged to work only with well-fixed material; damaged, decomposed, or strongly flattened specimens should not be used for taxonomic studies, and type specimens must always be deposited in internationally recognized collections.

  1. Biting midges (Culicoides, Diptera) transmit Haemoproteus parasites of owls: evidence from sporogony and molecular phylogeny.

    PubMed

    Bukauskaitė, Dovilė; Žiegytė, Rita; Palinauskas, Vaidas; Iezhova, Tatjana A; Dimitrov, Dimitar; Ilgūnas, Mikas; Bernotienė, Rasa; Markovets, Mikhail Yu; Valkiūnas, Gediminas

    2015-06-04

    Haemoproteus parasites are widespread, and several species cause diseases both in birds and blood-sucking insects. These pathogens are transmitted by dipterans belonging to the Ceratopogonidae and Hippoboscidae, however certain vector species remain unknown for the majority of Haemoproteus spp. Owls are often infected by Haemoproteus parasites, but experimental studies on vectors of these infections are lacking. The aim of this study was to investigate sporogonic development of two widespread Haemoproteus parasites of owls, H. noctuae and H. syrnii in experimentally infected biting midges Culicoides impunctatus and Culicoides nubeculosus. We also followed in vitro sporogonic development of these infections and determined their phylogenetic relationships with Haemoproteus spp., for which vectors have been identified. Wild-caught C. impunctatus and laboratory reared C. nubeculosus were infected experimentally by allowing them to take blood meals on one individual long-eared owl (Asio otus) and one tawny owl (Strix aluco) harbouring mature gametocytes of H. noctuae (lineage hCIRCUM01) and H. syrnii (hCULCIB01), respectively. The engorged insects were maintained in the laboratory at 16-18 °C, and dissected at intervals in order to follow the development of ookinetes, oocysts and sporozoites. We also observed in vitro development of sexual stages of both parasites by exposure of infected blood to air. The parasite lineages were determined by polymerase chain reaction-based methods. Bayesian phylogeny was constructed in order to determine the relationships of owl parasites with other avian Haemoproteus spp., for which vectors have been identified. Both H. noctuae and H. syrnii completed sporogony in C. nubeculosus, and H. noctuae completed sporogony in C. impunctatus. Ookinetes, oocysts and sporozoites of these parasites were reported and described. Gametes and ookinetes of both species readily developed in vitro. In accordance with sporogony data, the phylogenetic

  2. Spatial relationship between Taenia solium tapeworm carriers and necropsy cyst burden in pigs

    PubMed Central

    Ayvar, Viterbo; Gamboa, Ricardo; Muro, Claudio; Moyano, Luz M.; Benavides, Victor; Flecker, Robert H.; Garcia, Hector H.; O’Neal, Seth E.

    2017-01-01

    Background Taenia solium, a parasite that affects humans and pigs, is the leading cause of preventable epilepsy in the developing world. Geographic hotspots of pigs testing positive for serologic markers of T. solium exposure have been observed surrounding the locations of human tapeworm carriers. This clustered pattern of seropositivity in endemic areas formed the basis for geographically targeted control interventions, which have been effective at reducing transmission. In this study, we further explore the spatial relationship between human tapeworm carriers and infected pigs using necroscopic examination as a quantitative gold-standard diagnostic to detect viable T. solium cyst infection in pigs. Methodology/Principal findings We performed necroscopic examinations on pigs from 7 villages in northern Peru to determine the number of viable T. solium cysts in each pig. Participating humans in the study villages were tested for T. solium tapeworm infection (i.e., taeniasis) with an ELISA coproantigen assay, and the distances from each pig to its nearest human tapeworm carrier were calculated. We assessed the relationship between proximity to a tapeworm carrier and the prevalence of light, moderate, and heavy cyst burden in pigs. The prevalence of pig infection was greatest within 50 meters of a tapeworm carrier and decreased monotonically as distance increased. Pigs living less than 50 meters from a human tapeworm carrier were 4.6 times more likely to be infected with at least one cyst than more distant pigs. Heavier cyst burdens, however, were not more strongly associated with proximity to tapeworm carriers than light cyst burdens. Conclusion/Significance Our study shows that human tapeworm carriers and pigs with viable T. solium cyst infection are geographically correlated in endemic areas. This finding supports control strategies that treat humans and pigs based on their proximity to other infected individuals. We did not, however, find sufficient evidence that

  3. Cerebellar cysticercosis caused by larval Taenia crassiceps tapeworm in immunocompetent woman, Germany.

    PubMed

    Ntoukas, Vasileios; Tappe, Dennis; Pfütze, Daniel; Simon, Michaela; Holzmann, Thomas

    2013-12-01

    Human cysticercosis caused by Taenia crassiceps tapeworm larvae involves the muscles and subcutis mostly in immunocompromised patients and the eye in immunocompetent persons. We report a successfully treated cerebellar infection in an immunocompetent woman. We developed serologic tests, and the parasite was identified by histologic examination and 12s rDNA PCR and sequencing.

  4. Cerebellar Cysticercosis Caused by Larval Taenia crassiceps Tapeworm in Immunocompetent Woman, Germany

    PubMed Central

    Ntoukas, Vasileios; Tappe, Dennis; Pfütze, Daniel; Simon, Michaela

    2013-01-01

    Human cysticercosis caused by Taenia crassiceps tapeworm larvae involves the muscles and subcutis mostly in immunocompromised patients and the eye in immunocompetent persons. We report a successfully treated cerebellar infection in an immunocompetent woman. We developed serologic tests, and the parasite was identified by histologic examination and 12s rDNA PCR and sequencing. PMID:24274258

  5. Pacific Broad Tapeworm Adenocephalus pacificus as a Causative Agent of Globally Reemerging Diphyllobothriosis.

    PubMed

    Kuchta, Roman; Serrano-Martínez, Marcus Enrique; Scholz, Tomas

    2015-10-01

    The Pacific broad tapeworm Adenocephalus pacificus (syn. Diphyllobothrium pacificum) is the causative agent of the third most common fish-borne cestodosis among humans. Although most of the nearly 1,000 cases among humans have been reported in South America (Peru, Chile, and Ecuador), cases recently imported to Europe demonstrate the potential for spread of this tapeworm throughout the world as a result of global trade of fresh or chilled marine fish and travel or migration of humans. We provide a comprehensive survey of human cases of infection with this zoonotic parasite, summarize the history of this re-emerging disease, and identify marine fish species that may serve as a source of human infection when eaten raw or undercooked.

  6. Ultrastructural aspects of spermatogenesis, testes, and vas deferens in the parthenogenetic tapeworm Atractolytocestus huronensis Anthony, 1958 (Cestoda: Caryophyllidea), a carp parasite from Slovakia.

    PubMed

    Bruňanská, Magdaléna; Nebesářová, Jana; Oros, Mikuláš

    2011-01-01

    Spermatogenesis, testes, and vas deferens in the parthenogenetic monozoic tapeworm Atractolytocestus huronensis Anthony, 1958 (Cestoda: Caryophyllidea) from Slovakia, parasitizing the carp Cyprinus carpio L., have been investigated by means of transmission electron microscopy for the first time. The present results show that helminths with parthenogenetic and normal reproduction may share some common spermatology features, e.g., dense cytoplasm of the peripherally localized spermatogonia or a rosette type of spermatogenesis. In contrast to tapeworms with normal reproduction, the most prominent ultrastructural characteristic of the spermatocytes of A. huronensis is fragmentation of their nuclei. This clear feature of cell degeneration might be a consequence of the aberrant first meiotic division. Peripheral cortical microtubules and a single centriole, indicators of the ongoing spermiogenesis, were observed only very rarely in the early spermatids. Characteristics of normal spermiogenesis, i.e., apical dense material in the zone of differentiation in early stages of spermiogenesis, flagellar rotation, and proximo-distal fusion, were never found in the present study. The testes follicles are surrounded by a thin cytoplasmic sheath underlined by a basal lamina. Vas deferens is lined by flat epithelium with numerous surface lamellae and cilia. Mature, functional spermatozoa were not observed in the vas deferens of A. huronensis from Slovakia.

  7. 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.

  8. 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.

  9. Pacific Broad Tapeworm Adenocephalus pacificus as a Causative Agent of Globally Reemerging Diphyllobothriosis

    PubMed Central

    Serrano-Martínez, Marcus Enrique; Scholz, Tomas

    2015-01-01

    The Pacific broad tapeworm Adenocephalus pacificus (syn. Diphyllobothrium pacificum) is the causative agent of the third most common fish-borne cestodosis among humans. Although most of the nearly 1,000 cases among humans have been reported in South America (Peru, Chile, and Ecuador), cases recently imported to Europe demonstrate the potential for spread of this tapeworm throughout the world as a result of global trade of fresh or chilled marine fish and travel or migration of humans. We provide a comprehensive survey of human cases of infection with this zoonotic parasite, summarize the history of this re-emerging disease, and identify marine fish species that may serve as a source of human infection when eaten raw or undercooked. PMID:26402440

  10. [Dipylidium caninum, a rare parasite in man].

    PubMed

    Brandstetter, W; Auer, H

    1994-01-01

    Dipylidium caninum, the dog tapeworm, is a common cosmopolitan parasite of dogs and cats. Infestations of man are observed only sporadically. We report the case of a 22 months-old child living in Upper Austria with dipylidiasis. The parasite is briefly outlined with respect to biology, epidemiology, clinical features, diagnosis, therapy and prevention.

  11. Novel praziquantel treatment regime for controlling Asian tapeworm infections in pond-reared fish

    USGS Publications Warehouse

    Iles, Alison C.; Archdeacon, Thomas P.; Bonar, Scott A.

    2012-01-01

    The Asian tapeworm Bothriocephalus achelognathii is an intestinal fish parasite that is nonnative to but widespread throughout the southwestern United States. Praziquantel is an anthelminthic drug commonly used to treat fish for Asian tapeworm; however, it does not kill tapeworm eggs, so the water in ponds used for fish rearing must be exchanged after treatment. Our objective was to determine whether a system containing both an intermediate copepod host and a definitive fish host for Asian tapeworm could be treated without exchanging the water by using a follow-up treatment for any tapeworms that developed from eggs released before or during the first treatment. Here, we have described a new praziquantel treatment regimen to control Asian tapeworm infections in freshwater-reared fish. To evaluate the efficacy of this regimen, we stocked 50 red shiners Cyprinella lutrensis and an intermediate copepod host, Cyclops vernalis, into each of six pond mesocosms containing artificial macrophytes, sand, and gravel to simulate natural pools and provide suitable substrate for the copepod's life history. The test fish population had been naturally infected with B. achelognathii and had an initial infection prevalence of 14% and an infection intensity of 2.14 ± 2.19 (mean ± SD) worms per fish. Three mesocosms were treated twice, each with 2.5 mg/L praziquantel; 19 d passed between treatments to allow for possible reinfection to occur. After a 2.5-month posttreatment period to allow any remaining tapeworms to reestablish themselves, we killed and dissected all of the remaining fish. No worms were found in treated fish; however, the control group had an infection prevalence of 18 ± 6% and an infection intensity of 3.45 ± 2.1 worms per fish. Based on these results, we concluded that the praziquantel treatment regime administered was efficacious and suggest testing it on a larger scale. We caution that praziquantel has not been approved by the U.S. Food and Drug Administration

  12. 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.

  13. Challenges and opportunities in detecting Taenia solium tapeworm carriers in Los Angeles County California, 2009-2014.

    PubMed

    Croker, Curtis

    2015-12-01

    Carriers of the pork tapeworm, Taenia solium, are the sole source of neurocysticercosis, a parasitic tissue infection that can be chronic and severe. Identifying T. solium tapeworm carriers is challenging. Many are asymptomatic and go undetected and unreported. In addition, T. solium is difficult to distinguish from other Taenia species of less concern. From 2009 to 2014, 24 taeniasis cases were reported to the Los Angeles County (LAC) Department of Public Health. Twenty reports were received solely from our automated electronic laboratory reporting system (ELR), two from health care providers, and two were generated internally from investigation of households with a reported neurocysticercosis case. Further investigation identified one T. solium carrier originally reported by ELR and one identified from a neurocysticercosis case investigation. These results suggest that T. solium tapeworm carriers can be identified from investigation of ELR reports of unspeciated Taenia cases as well as from households of neurocysticercosis cases. Published by Elsevier Ltd.

  14. 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

  15. Phylogeny of haemosporidian blood parasites revealed by a multi-gene approach.

    PubMed

    Borner, Janus; Pick, Christian; Thiede, Jenny; Kolawole, Olatunji Matthew; Kingsley, Manchang Tanyi; Schulze, Jana; Cottontail, Veronika M; Wellinghausen, Nele; Schmidt-Chanasit, Jonas; Bruchhaus, Iris; Burmester, Thorsten

    2016-01-01

    The apicomplexan order Haemosporida is a clade of unicellular blood parasites that infect a variety of reptilian, avian and mammalian hosts. Among them are the agents of human malaria, parasites of the genus Plasmodium, which pose a major threat to human health. Illuminating the evolutionary history of Haemosporida may help us in understanding their enormous biological diversity, as well as tracing the multiple host switches and associated acquisitions of novel life-history traits. However, the deep-level phylogenetic relationships among major haemosporidian clades have remained enigmatic because the datasets employed in phylogenetic analyses were severely limited in either gene coverage or taxon sampling. Using a PCR-based approach that employs a novel set of primers, we sequenced fragments of 21 nuclear genes from seven haemosporidian parasites of the genera Leucocytozoon, Haemoproteus, Parahaemoproteus, Polychromophilus and Plasmodium. After addition of genomic data from 25 apicomplexan species, the unreduced alignment comprised 20,580 bp from 32 species. Phylogenetic analyses were performed based on nucleotide, codon and amino acid data employing Bayesian inference, maximum likelihood and maximum parsimony. All analyses resulted in highly congruent topologies. We found consistent support for a basal position of Leucocytozoon within Haemosporida. In contrast to all previous studies, we recovered a sister group relationship between the genera Polychromophilus and Plasmodium. Within Plasmodium, the sauropsid and mammal-infecting lineages were recovered as sister clades. Support for these relationships was high in nearly all trees, revealing a novel phylogeny of Haemosporida, which is robust to the choice of the outgroup and the method of tree inference. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Impairment of the chemical defence of the beetle, Tenebrio molitor, by metacestodes (cysticeroids) of the tapeworm, Hymenolepis diminuta.

    PubMed

    Blankespoor, C L; Pappas, P W; Eisner, T

    1997-07-01

    The defensive glands of beetles, Tenebrio molitor, infected with metacestodes (cysticercoids) of Hymenolepis diminuta are everted less frequently upon stimulation, and contain less toluquinone (methylbenzoquinone) and m-cresol, than glands of uninfected controls. These differences, as shown in predation trials with wild rats, increase the likelihood that both cysticercoids and beetles will be ingested by the tapeworm's definitive host. This is the first documented case of a parasite inhibiting the chemical defence of an intermediate host, and one of only a few reports of parasite-induced manipulation of host biology supported by empirical evidence implicating facilitated parasite transmission between host species.

  17. Two cases of dipylidiasis (dog tapeworm infection) in children: update on an old problem.

    PubMed

    Hamrick, H J; Drake, W R; Jones, H M; Askew, A P; Weatherly, N F

    1983-07-01

    Children in households with dogs and cats may become infected with the dog tapeworm more frequently than suspected. Because of age-appropriate hand-to-mouth exploration, young infants and toddlers, through contact with fleas on pets, floors, and furnishings, are particularly susceptible. Knowledge of the life cycle of this animal parasite and the manner in which children acquire and demonstrate infection can lead to early diagnosis and effective treatment.

  18. 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

  19. Insights using a molecular approach into the life cycle of a tapeworm infecting great white sharks.

    PubMed

    Randhawa, Haseeb S

    2011-04-01

    The great white shark Carcharodon carcharias Linnaeus, 1758 is a versatile and fierce predator (and responsible for many shark attacks on humans). This apex predator feeds on a wide range of organisms including teleosts, other elasmobranchs, cephalopods, pinnipeds, and cetaceans. Although much is known about its diet, no trophic links have been empirically identified as being involved in the transmission of its tapeworm parasites. Recently, the use of molecular tools combined with phylogenetics has proven useful to identify larval and immature stages of marine tapeworms; utilization of the technique has been increasing rapidly. However, the usefulness of this approach remains limited by the availability of molecular data. Here, I employed gene sequence data from the D2 region of the large subunit of ribosomal DNA to link adults of the tapeworm Clistobothrium carcharodoni Dailey and Vogelbein, 1990 (Cestoda: Tetraphyllidea) to larvae for which sequence data for this gene are available. The sequences from the adult tapeworms were genetically identical (0% sequence divergence) to those available on GenBank for "SP" 'small' Scolex pleuronectis recovered from the striped dolphin (Stenella coeruleoalba) and Risso's dolphin (Grampus griseus). This study is the first to provide empirical evidence linking the trophic interaction between great white sharks and cetaceans as a definitive route for the successful transmission of a tetraphyllidean tapeworm. Using the intensity of infection data from this shark and from cetaceans as proxies for the extent of predation, I estimate that this individual shark would have consumed between 9 to 83 G. griseus , fresh, dead, or both, in its lifetime.

  20. Metazoan parasites of deep-sea fishes from the South Eastern Pacific: Exploring the role of ecology and host phylogeny

    NASA Astrophysics Data System (ADS)

    Ñacari, Luis A.; Oliva, Marcelo E.

    2016-09-01

    We studied the parasite fauna of five deep-sea fish species (>1000 m depth), Three members of Macrouridae (Macrourus holotrachys, Coryphaenoides ariommus and Coelorhynchus sp.), the Morid Antimora rostrata and the Synaphobranchidae Diaptobranchus capensis caught as by-catch of the Patagonian toothfish (Dissostichus eleginoides) from central and northern Chile at depths between 1000 and 2000 m. The parasite fauna of M. holotrachys was the most diverse, with 32 species (The higher reported for Macrourus spp.) and the lower occur in the basketwork eel D. capensis (one species). Trophically transmitted parasites, mainly Digenea and Nematoda explain 59.1% of the total number of species obtained (44 species) and the 81.1% of the 1020 specimens collected. Similarity analysis based on prevalence as well as a Correspondence analysis shows that higher similitude in parasite fauna occurs in members of Macrouridae. The importance of diet and phylogeny is discussed as forces behind the characteristics of the endoparasite and ectoparasite communities found in the studied fish species.

  1. Inhibition of Tapeworm Thioredoxin and Glutathione Pathways by an Oxadiazole N-Oxide Leads to Reduced Mesocestoides vogae Infection Burden in Mice.

    PubMed

    Pasquet, Vivian; Bisio, Hugo; López, Gloria V; Romanelli-Cedrez, Laura; Bonilla, Mariana; Saldaña, Jenny; Salinas, Gustavo

    2015-06-26

    Parasitic flatworms cause serious infectious diseases that affect humans and livestock in vast regions of the world, yet there are few effective drugs to treat them. Thioredoxin glutathione reductase (TGR) is an essential enzyme for redox homeostasis in flatworm parasites and a promising pharmacological target. We purified to homogeneity and characterized the TGR from the tapeworm Mesocestoides vogae (syn. M. corti). This purification revealed absence of conventional TR and GR. The glutathione reductase activity of the purified TGR exhibits a hysteretic behavior typical of flatworm TGRs. Consistently, M. vogae genome analysis revealed the presence of a selenocysteine-containing TGR and absence of conventional TR and GR. M. vogae thioredoxin and glutathione reductase activities were inhibited by 3,4-bis(phenylsulfonyl)-1,2,5-oxadiazole N2-oxide (VL16E), an oxadiazole N-oxide previously identified as an inhibitor of fluke and tapeworm TGRs. Finally, we show that mice experimentally infected with M. vogae tetrathyridia and treated with either praziquantel, the reference drug for flatworm infections, or VL16E exhibited a 28% reduction of intraperitoneal larvae numbers compared to vehicle treated mice. Our results show that oxadiazole N-oxide is a promising chemotype in vivo and highlights the convenience of M. vogae as a model for rapid assessment of tapeworm infections in vivo.

  2. Ecological aspects of the occurrence of asian tapeworm, Bothriocephalus acheilognathi Yamaguti, 1934 infection in the largemouth yellowfish, Labeobarbus kimberleyensis ( Gilchrist and Thompson, 1913) in the Vaal Dam, South Africa

    NASA Astrophysics Data System (ADS)

    Retief, N.-R.; Avenant-Oldewage, A.; du Preez, H. H.

    Infection of fish by the Asian tapeworm can damage intestines and cause abnormal growth. Eighty largemouth yellowfish Labeobarbus kimberleyensis were collected in the Vaal Dam (26°52.249‧S, 28°10.249‧E) with the aid of gill nets during a study between April 2005 and February 2006. The fish were killed and the weight and length determined. Thereafter the intestines were removed, the length determined and the intestines opened to expose the tapeworms. The distance between the beginning of the intestine and the attachment position of the first tapeworm was measured, and thereafter all the worms were collected. The prevalence, abundance and mean intensity was calculated for all the surveys. Seasonality and intensity of tapeworms were compared to the intestine and total lengths of the fish. All the tapeworms were identified as the Asian Tapeworm Bothriocephalus acheilognathi Yamaguti, 1934. The position of the first tapeworm was located between 10% and 20% from the anterior end of the intestine in close proximity to the bile opening. A total of 100% prevalence was recorded for all the surveys and the highest mean intensity of 231.1 was recorded during the autumn survey. The lowest mean intensity of 73.7 was recorded during the summer survey. Although the infection rates were very high, the fish condition was good and apparently the fecundity of the fish was not negatively affected as young fish fry was collected during the summer survey. Parasite numbers are higher and differ from a study conducted in 2000 and this is attributed to water temperature and water quality. No correlation was observed between parasite intensity and total length of each fish. This indicates that intensity is not dependant on host size and that infection is not the result of a buildt of over years.

  3. The catholic taste of broad tapeworms - multiple routes to human infection.

    PubMed

    Waeschenbach, Andrea; Brabec, Jan; Scholz, Tomáš; Littlewood, D Timothy J; Kuchta, Roman

    2017-11-01

    Broad tapeworms (Cestoda: Diphyllobothriidea) are the principal agents of widespread food-borne cestodosis. Diphyllobothriosis and diplogonoporosis, caused by members of the genera Diphyllobothrium, Diplogonoporus and Adenocephalus, are the most common fish cestodoses with an estimated 20million people infected worldwide, and has seen recent (re)emergences in Europe due to the increasing popularity of eating raw or undercooked fish. Sparganosis is a debilitating and potentially lethal disease caused by the larvae of the genus Spirometra, which occurs throughout much of the (sub)tropics and is caused by the consumption of raw snakes and frogs, and drinking water contaminated by infected copepods. Both diseases are caused by several species, but the frequency by which the transition to humans has occurred has never been studied. Using a phylogenetic framework of 30 species based on large and small nuclear ribosomal RNA subunits (ssrDNA, lsrDNA), large subunit mitochondrial ribosomal RNA (rrnL) and cytochrome c oxidase subunit I (cox1), we hypothesize that humans have been acquired asaccidental hosts four times across the tree of life of diphyllobothriideans. However, polytomies prevent an unambiguous reconstruction of the evolution of intermediate and definitive host use. The broad host spectrum and the frequency with which switching between major host groups appears to have occurred, may hold the answer as to why accidental human infection occurred multiple times across the phylogeny of diphyllobothriideans. In this study Diplogonoporus is determined to be the junior synonym of Diphyllobothrium. Furthermore, we divide the latter polyphyletic genus into (i) the resurrected genus Dibothriocephalus to include freshwater and terrestrial species including Dibothriocephalus dendriticus, Dibothriocephalus latus and Dibothriocephalus nihonkaiensis as the most common parasites of humans, and (ii) the genus Diphyllobothrium to accommodate parasites from cetaceans including

  4. Update on the distribution of the co-invasive Schyzocotyle acheilognathi (= Bothriocephalus acheilognathi), the Asian fish tapeworm, in freshwater fishes of Mexico.

    PubMed

    Pérez-Ponce de León, G; Lagunas-Calvo, O; García-Prieto, L; Briosio-Aguilar, R; Aguilar-Aguilar, R

    2018-05-01

    The Asian fish tapeworm, Schyzocotyle acheilognathi (syn. Bothriocephalus acheilognathi) represents a threat to freshwater fish, mainly cyprinids, across the globe. This tapeworm possesses an extraordinary ability to adapt to different environmental conditions and, because of that, from its natural geographical origin in mainland Asia, it has colonized every continent except Antarctica. It is thought that this pathogenic tapeworm was first co-introduced into Mexico in 1965 from China, with the grass carp Ctenopharyngodon idella, although the first formal record of its presence was published in 1981. Over the past 35 years, the Asian fish tapeworm has invaded about 22% of the freshwater fish in Mexico. Because fish communities in Mexico are characterized by high species richness and levels of endemism, S. acheilognathi is considered as a co-introduced and co-invasive species. In this review, we update the geographic distribution and host spectrum of the Asian fish tapeworm in Mexico. Up until December 2016, the tapeworm had been recorded in 110 freshwater fish species (96 native and 14 introduced), included in 51 genera, 11 families and 4 orders; it was also widely distributed in all types of aquatic environments, and has been found in 214 localities. We present novel data from a survey aimed at establishing the distribution pattern of the tapeworm in native freshwater fishes of two rivers in north-central Mexico, and the genetic variation among individuals of this co-invasive species collected from different host species and localities. We discuss briefly the factors that have determined the remarkable invasive success of this parasite in freshwater systems in Mexico.

  5. 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.

  6. Isotopic discrimination of stable isotopes of nitrogen (δ15N) and carbon (δ13C) in a host-specific holocephalan tapeworm.

    PubMed

    Navarro, J; Albo-Puigserver, M; Coll, M; Saez, R; Forero, M G; Kutcha, R

    2014-09-01

    During the past decade, parasites have been considered important components of their ecosystems since they can modify food-web structures and functioning. One constraint to the inclusion of parasites in food-web models is the scarcity of available information on their feeding habits and host-parasite relationships. The stable isotope approach is suggested as a useful methodology to determine the trophic position and feeding habits of parasites. However, the isotopic approach is limited by the lack of information on the isotopic discrimination (ID) values of parasites, which is pivotal to avoiding the biased interpretation of isotopic results. In the present study we aimed to provide the first ID values of δ(15)N and δ(13)C between the gyrocotylidean tapeworm Gyrocotyle urna and its definitive host, the holocephalan Chimaera monstrosa. We also test the effect of host body size (body length and body mass) and sex of the host on the ID values. Finally, we illustrate how the trophic relationships of the fish host C. monstrosa and the tapeworm G. urna could vary relative to ID values. Similar to other studies with parasites, the ID values of the parasite-host system were negative for both isotopic values of N (Δδ(15)N = - 3.33 ± 0.63‰) and C (Δδ(13)C = - 1.32 ± 0.65‰), independent of the sex and size of the host. By comparing the specific ID obtained here with ID from other studies, we illustrate the importance of using specific ID in parasite-host systems to avoid potential errors in the interpretation of the results when surrogate values from similar systems or organisms are used.

  7. 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.

  8. In vitro screening for cestocidal activity of three species of Cassia plants against the tapeworm Raillietina tetragona.

    PubMed

    Kundu, S; Lyndem, L M

    2013-06-01

    Different species of Cassia plant are widely available in India and are commonly used either for their laxative, antimicrobial or antibacterial activity. In the present study the effectiveness in vitro of the crude alcoholic extracts of three species, namely Cassia alata, C. occidentalis and C. angustifolia, in the early paralysis and mortality of the fowl tapeworm Raillietina tetragona at concentrations ranging from 5 to 80 mg/ml was investigated. Time of paralysis and death were monitored frequently. Immediately after paralysis the tapeworms were processed for electron microscopic studies. While the untreated or control parasites survived for 81.93 ± 5.85 h, the parasites treated with C. alata took less time (1.68 ± 0.27 h) to be paralysed, followed by those treated with C. angustifolia (2.95 ± 0.29 h). Although C. occidentalis took more time (4.13 ± 0.31 h) to paralyse, in combination with either C. alata or C. angustifolia the time taken to paralyse became shorter. All the plant-treated parasites showed irrevocable changes in the scolex and proglottids as compared with the control, and these observations are comparable with those obtained with praziquantel. These results indicate that the three plants tested can be claimed to have anthelmintic activity in addition to their known properties, both when used individually and in combination. Further investigations will be required to evaluate their mechanism of action.

  9. Complete mitochondrial genomes of Taenia multiceps, T. hydatigena and T. pisiformis: additional molecular markers for a tapeworm genus of human and animal health significance.

    PubMed

    Jia, Wan-Zhong; Yan, Hong-Bin; Guo, Ai-Jiang; Zhu, Xing-Quan; Wang, Yu-Chao; Shi, Wan-Gui; Chen, Hao-Tai; Zhan, Fang; Zhang, Shao-Hua; Fu, Bao-Quan; Littlewood, D Timothy J; Cai, Xue-Peng

    2010-07-22

    Mitochondrial genomes provide a rich source of molecular variation of proven and widespread utility in molecular ecology, population genetics and evolutionary biology. The tapeworm genus Taenia includes a diversity of tapeworm parasites of significant human and veterinary importance. Here we add complete sequences of the mt genomes of T. multiceps, T. hydatigena and T. pisiformis, to a data set of 4 published mtDNAs in the same genus. Seven complete mt genomes of Taenia species are used to compare and contrast variation within and between genomes in the genus, to estimate a phylogeny for the genus, and to develop novel molecular markers as part of an extended mitochondrial toolkit. The complete circular mtDNAs of T. multiceps, T. hydatigena and T. pisiformis were 13,693, 13,492 and 13,387 bp in size respectively, comprising the usual complement of flatworm genes. Start and stop codons of protein coding genes included those found commonly amongst other platyhelminth mt genomes, but the much rarer initiation codon GTT was inferred for the gene atp6 in T. pisiformis. Phylogenetic analysis of mtDNAs offered novel estimates of the interrelationships of Taenia. Sliding window analyses showed nad6, nad5, atp6, nad3 and nad2 are amongst the most variable of genes per unit length, with the highest peaks in nucleotide diversity found in nad5. New primer pairs capable of amplifying fragments of variable DNA in nad1, rrnS and nad5 genes were designed in silico and tested as possible alternatives to existing mitochondrial markers for Taenia. With the availability of complete mtDNAs of 7 Taenia species, we have shown that analysis of amino acids provides a robust estimate of phylogeny for the genus that differs markedly from morphological estimates or those using partial genes; with implications for understanding the evolutionary radiation of important Taenia. Full alignment of the nucleotides of Taenia mtDNAs and sliding window analysis suggests numerous alternative gene

  10. Complete mitochondrial genomes of Taenia multiceps, T. hydatigena and T. pisiformis: additional molecular markers for a tapeworm genus of human and animal health significance

    PubMed Central

    2010-01-01

    Background Mitochondrial genomes provide a rich source of molecular variation of proven and widespread utility in molecular ecology, population genetics and evolutionary biology. The tapeworm genus Taenia includes a diversity of tapeworm parasites of significant human and veterinary importance. Here we add complete sequences of the mt genomes of T. multiceps, T. hydatigena and T. pisiformis, to a data set of 4 published mtDNAs in the same genus. Seven complete mt genomes of Taenia species are used to compare and contrast variation within and between genomes in the genus, to estimate a phylogeny for the genus, and to develop novel molecular markers as part of an extended mitochondrial toolkit. Results The complete circular mtDNAs of T. multiceps, T. hydatigena and T. pisiformis were 13,693, 13,492 and 13,387 bp in size respectively, comprising the usual complement of flatworm genes. Start and stop codons of protein coding genes included those found commonly amongst other platyhelminth mt genomes, but the much rarer initiation codon GTT was inferred for the gene atp6 in T. pisiformis. Phylogenetic analysis of mtDNAs offered novel estimates of the interrelationships of Taenia. Sliding window analyses showed nad6, nad5, atp6, nad3 and nad2 are amongst the most variable of genes per unit length, with the highest peaks in nucleotide diversity found in nad5. New primer pairs capable of amplifying fragments of variable DNA in nad1, rrnS and nad5 genes were designed in silico and tested as possible alternatives to existing mitochondrial markers for Taenia. Conclusions With the availability of complete mtDNAs of 7 Taenia species, we have shown that analysis of amino acids provides a robust estimate of phylogeny for the genus that differs markedly from morphological estimates or those using partial genes; with implications for understanding the evolutionary radiation of important Taenia. Full alignment of the nucleotides of Taenia mtDNAs and sliding window analysis suggests

  11. Photoreactivating enzyme activity in the rat tapeworm, Hymenolepis diminuta

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

    Woodhead, A.D.; Achey, P.M.

    1981-06-01

    There has been considerable speculation about the occurrence of photoreactivating enzyme in different organisms and about its biological purpose. We have developed a simple, sensitive assay for estimating pyrimidine dimers in DNA which is useful in making a rapid survey for the presence of the enzyme. Using this method, we have found photoreactivating enzyme activity in the tissues of the rat tapeworm Hymenolepis diminuta. This parasite spends the majority of its life span in the bodies of its definitive or intermediate hosts, but a period is spent externally. We suggest that photoreactivating enzyme may be important in preserving the integritymore » of embryonic DNA during this free-living stage.« less

  12. Photoreactivating enzyme activity in the rat tapeworm, Hymenolepis diminuta

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

    Woodhead, A.D.; Achey, P.M.

    1981-01-01

    There has been considerable speculation about the occurrence of photoreactivating enzyme in different organisms and about its biologic purpose. We have developed a simple, sensitive assay for estimating pyrimidine dimers in DNA which is useful in making a rapid survey for the presence of the enzyme. Using this method, we have found photoreactivating enzyme activity in the tissues of the rat tapeworm, Hymenolepis diminuta. This parasite spends the majority of its life span in the bodies of its definitive or intermediate hosts, but a period is spent externally. We suggest that photoreactivating enzyme may be important in perserving the integritymore » of embryonic DNA during this free-living stage.« less

  13. Sympatric distribution of three human Taenia tapeworms collected between 1935 and 2005 in Korea.

    PubMed

    Jeon, Hyeong-Kyu; Kim, Kyu-Heon; Chai, Jong-Yil; Yang, Hyun-Jong; Rim, Han-Jong; Eom, Keeseon S

    2008-12-01

    Taeniasis has been known as one of the prevalent parasitic infections in Korea. Until recently, Taenia saginata had long been considered a dominant, and widely distributed species but epidemiological profiles of human Taenia species in Korea still remain unclear. In order to better understand distribution patterns of human Taenia tapeworms in Korea, partial nucleotide sequences of mitochondrial cox1 and ITS2 (internal transcribed spacer 2) were determined, along with morphological examinations, on 68 Taenia specimens obtained from university museum collections deposited since 1935. Genomic DNA was extracted from formalin-preserved specimens. Phylogenetic relationships among the genotypes (cox1 haplotype) detected in this study were inferred using the neighbor-joining method as a tree building method. Morphological and genetic analyses identified 3 specimens as T. solium, 51 specimens as T. asiatica, and 14 specimens as T. saginata. Our results indicate that all 3 Taenia tapeworms are sympatrically distributed in Korea with T. asiatica dominating over T. saginata and T. solium.

  14. Sympatric Distribution of Three Human Taenia Tapeworms Collected between 1935 and 2005 in Korea

    PubMed Central

    Jeon, Hyeong-Kyu; Kim, Kyu-Heon; Chai, Jong-Yil; Yang, Hyun-Jong; Rim, Han-Jong

    2008-01-01

    Taeniasis has been known as one of the prevalent parasitic infections in Korea. Until recently, Taenia saginata had long been considered a dominant, and widely distributed species but epidemiological profiles of human Taenia species in Korea still remain unclear. In order to better understand distribution patterns of human Taenia tapeworms in Korea, partial nucleotide sequences of mitochondrial cox1 and ITS2 (internal transcribed spacer 2) were determined, along with morphological examinations, on 68 Taenia specimens obtained from university museum collections deposited since 1935. Genomic DNA was extracted from formalin-preserved specimens. Phylogenetic relationships among the genotypes (cox1 haplotype) detected in this study were inferred using the neighbor-joining method as a tree building method. Morphological and genetic analyses identified 3 specimens as T. solium, 51 specimens as T. asiatica, and 14 specimens as T. saginata. Our results indicate that all 3 Taenia tapeworms are sympatrically distributed in Korea with T. asiatica dominating over T. saginata and T. solium. PMID:19127329

  15. 9 CFR 311.24 - Hogs affected with tapeworm cysts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Hogs affected with tapeworm cysts. 311.24 Section 311.24 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... affected with tapeworm cysts. Carcasses of hogs affected with tapeworm cysts (Cysticercus cellulosae) may...

  16. 9 CFR 311.24 - Hogs affected with tapeworm cysts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Hogs affected with tapeworm cysts. 311.24 Section 311.24 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... affected with tapeworm cysts. Carcasses of hogs affected with tapeworm cysts (Cysticercus cellulosae) may...

  17. 9 CFR 311.24 - Hogs affected with tapeworm cysts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Hogs affected with tapeworm cysts. 311.24 Section 311.24 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... affected with tapeworm cysts. Carcasses of hogs affected with tapeworm cysts (Cysticercus cellulosae) may...

  18. 9 CFR 311.24 - Hogs affected with tapeworm cysts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Hogs affected with tapeworm cysts. 311.24 Section 311.24 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... affected with tapeworm cysts. Carcasses of hogs affected with tapeworm cysts (Cysticercus cellulosae) may...

  19. Environmental temperature variation influences fitness trade-offs and tolerance in a fish-tapeworm association.

    PubMed

    Franke, Frederik; Armitage, Sophie A O; Kutzer, Megan A M; Kurtz, Joachim; Scharsack, Jörn P

    2017-06-02

    Increasing temperatures are predicted to strongly impact host-parasite interactions, but empirical tests are rare. Host species that are naturally exposed to a broad temperature spectrum offer the possibility to investigate the effects of elevated temperatures on hosts and parasites. Using three-spined sticklebacks, Gasterosteus aculeatus L., and tapeworms, Schistocephalus solidus (Müller, 1776), originating from a cold and a warm water site of a volcanic lake, we subjected sympatric and allopatric host-parasite combinations to cold and warm conditions in a fully crossed design. We predicted that warm temperatures would promote the development of the parasites, while the hosts might benefit from cooler temperatures. We further expected adaptations to the local temperature and mutual adaptations of local host-parasite pairs. Overall, S. solidus parasites grew faster at warm temperatures and stickleback hosts at cold temperatures. On a finer scale, we observed that parasites were able to exploit their hosts more efficiently at the parasite's temperature of origin. In contrast, host tolerance towards parasite infection was higher when sticklebacks were infected with parasites at the parasite's 'foreign' temperature. Cold-origin sticklebacks tended to grow faster and parasite infection induced a stronger immune response. Our results suggest that increasing environmental temperatures promote the parasite rather than the host and that host tolerance is dependent on the interaction between parasite infection and temperature. Sticklebacks might use tolerance mechanisms towards parasite infection in combination with their high plasticity towards temperature changes to cope with increasing parasite infection pressures and rising temperatures.

  20. Asian fish tapeworm, Khawia japonensis (Yamaguti, 1934), has expanded its European invasive range.

    PubMed

    Oros, Mikuláš; Barčák, Daniel; Bazsalovicsová, Eva; Hanzelová, Vladimíra

    2015-05-01

    The invasive fish tapeworm, Khawia japonensis (Yamaguti, 1934) originally described in Japan, is reported for the first time in Slovakia. The tapeworm was found in farmed common carp (Cyprinus carpio L.) from East-Slovakian breeding fish pond. This finding is registered 4 years after the first announcement of this parasite in Europe (Po River Basin in Italy) in 2010 and increases its distribution area within this continent. Morphological characterization of K. japonensis supplemented with DNA sequences of cox1 and ribosomal lsrDNA genes is provided. Specimens from Slovakia phenotypically corresponded with those from feral and farmed carps from China, Vietnam, and Italy. Moreover, 100 and 98.7% identity of partial ribosomal lsrDNA gene and mitochondrial cox1 genes, respectively, were detected with K. japonensis from Japan. The invasive and pathogenic potential of K. japonensis in commercial breeding fisheries and its possible further spread in natural habitats is difficult to estimate for now. As yet, K. japonensis appears to be without a major impact on commercial breeding fisheries, but calls for more attention to the problem of biological invasions.

  1. Human intestinal parasites in crusader Acre: Evidence for migration with disease in the medieval period.

    PubMed

    Mitchell, Piers D; Anastasiou, Evilena; Syon, Danny

    2011-12-01

    The aim of this research is to highlight the role of ancient parasites as evidence for human migration in past populations. The material analysed was soil sediment from the excavation of a medieval cesspool in the city of Acre, in Israel. Archaeological stratigraphy and radiocarbon dating of a fragment of animal bone from the cesspool confirm its use in the 13th century CE, during the crusader period. At that time Acre was located in the Frankish Kingdom of Jerusalem. Soil samples from the cesspool were analysed and eggs of the roundworm (Ascaris lumbricoides) and fish tapeworm (Diphyllobothrium latum) were identified. The fish tapeworm has only been found in the mainland Near East once before, in a latrine of the crusader Order of St. John (Knights Hospitaller). It has been absent in all earlier cesspools, latrines and coprolites so far studied in the region. In contrast to its rarity in the Levant, the fish tapeworm was common in northern Europe during the medieval period. The presence of fish tapeworm eggs in a crusader period cesspool in Acre suggests its use by crusaders or pilgrims from northern Europe who travelled to the Levant carrying these parasites in their intestines. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. 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.

  3. Patterns of co-speciation and host switching in primate malaria parasites.

    PubMed

    Garamszegi, László Zsolt

    2009-05-22

    The evolutionary history of many parasites is dependent on the evolution of their hosts, leading to an association between host and parasite phylogenies. However, frequent host switches across broad phylogenetic distances may weaken this close evolutionary link, especially when vectors are involved in parasites transmission, as is the case for malaria pathogens. Several studies suggested that the evolution of the primate-infective malaria lineages may be constrained by the phylogenetic relationships of their hosts, and that lateral switches between distantly related hosts may have been occurred. However, no systematic analysis has been quantified the degree of phylogenetic association between primates and their malaria parasites. Here phylogenetic approaches have been used to discriminate statistically between events due to co-divergence, duplication, extinction and host switches that can potentially cause historical association between Plasmodium parasites and their primate hosts. A Bayesian reconstruction of parasite phylogeny based on genetic information for six genes served as basis for the analyses, which could account for uncertainties about the evolutionary hypotheses of malaria parasites. Related lineages of primate-infective Plasmodium tend to infect hosts within the same taxonomic family. Different analyses testing for congruence between host and parasite phylogenies unanimously revealed a significant association between the corresponding evolutionary trees. The most important factor that resulted in this association was host switching, but depending on the parasite phylogeny considered, co-speciation and duplication may have also played some additional role. Sorting seemed to be a relatively infrequent event, and can occur only under extreme co-evolutionary scenarios. The concordance between host and parasite phylogenies is heterogeneous: while the evolution of some malaria pathogens is strongly dependent on the phylogenetic history of their primate

  4. Spatial and temporal distribution of the Asian fish tapeworm Bothriocephalus acheilognathi (Cestoda: Bothriocephalidea) in the Rio Grande (Río Bravo del Norte).

    PubMed

    Bean, Megan G; Bonner, Timothy H

    2010-09-01

    Recent collections of the Asian fish tapeworm Bothriocephalus acheilognathi in the Rio Grande have raised concern about the potential impacts on Rio Grande endemic and imperiled fishes. The objectives of this study were to determine distribution and definitive hosts of the Asian fish tapeworm within the Rio Grande drainage and to quantify occurrences and abundances. In total, 1,992 fish spanning 11 families were collected and examined for Asian fish tapeworms in the Rio Grande and the Pecos and Devils rivers. The parasite was collected from red shiners Cyprinella lutrensis, Tamaulipas shiners Notropis braytoni, sand shiners N. stramineus, river carpsuckers Carpiodes carpio, plains killifish Fundulus zebrinus, western mosquitofish Gambusia affinis, blue suckers Cycleptus elongatus, blacktail shiners Cyprinella venusta, proserpine shiners Cyprinella proserpina, and Manantial roundnose minnow Dionda argentosa, with the latter four species being new host records. Monthly collections of red shiners from Big Bend National Park exhibited prevalence levels above 15% in January-March and December and below 10% during April-June and October. With over 50% of the Rio Grande icthyofauna in Texas considered imperiled, the occurrence and pathological effects of the Asian fish tapeworm in combination with reduced water quantity and quality and increased habitat fragmentation are of concern for these taxa.

  5. Migratory behavior of birds affects their coevolutionary relationship with blood parasites.

    PubMed

    Jenkins, Tania; Thomas, Gavin H; Hellgren, Olof; Owens, Ian P F

    2012-03-01

    Host traits, such as migratory behavior, could facilitate the dispersal of disease-causing parasites, potentially leading to the transfer of infections both across geographic areas and between host species. There is, however, little quantitative information on whether variation in such host attributes does indeed affect the evolutionary outcome of host-parasite associations. Here, we employ Leucocytozoon blood parasites of birds, a group of parasites closely related to avian malaria, to study host-parasite coevolution in relation to host behavior using a phylogenetic comparative approach. We reconstruct the molecular phylogenies of both the hosts and parasites and use cophylogenetic tools to assess whether each host-parasite association contributes significantly to the overall congruence between the two phylogenies. We find evidence for a significant fit between host and parasite phylogenies in this system, but show that this is due only to associations between nonmigrant parasites and their hosts. We also show that migrant bird species harbor a greater genetic diversity of parasites compared with nonmigrant species. Taken together, these results suggest that the migratory habits of birds could influence their coevolutionary relationship with their parasites, and that consideration of host traits is important in predicting the outcome of coevolutionary interactions. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  6. Validation of a novel saliva-based ELISA test for diagnosing tapeworm burden in horses.

    PubMed

    Lightbody, Kirsty L; Davis, Paul J; Austin, Corrine J

    2016-06-01

    Tapeworm infections pose a significant threat to equine health as they are associated with clinical cases of colic. Diagnosis of tapeworm burden using fecal egg counts (FECs) is unreliable, and, although a commercial serologic ELISA for anti-tapeworm antibodies is available, it requires a veterinarian to collect the blood sample. A reliable diagnostic test using an owner-accessible sample such as saliva could provide a cost-effective alternative for tapeworm testing in horses, and allow targeted deworming strategies. The purpose of the study was to statistically validate a saliva tapeworm ELISA test and compare to a tapeworm-specific IgG(T) serologic ELISA. Serum samples (139) and matched saliva samples (104) were collected from horses at a UK abattoir. The ileocecal junction and cecum were visually examined for tapeworms and any present were counted. Samples were analyzed using a serologic ELISA and the saliva tapeworm test. The test results were compared to tapeworm numbers and the various data sets were statistically analyzed. Saliva scores had strong positive correlations with both infection intensity (0.74) and serologic results (Spearman's rank coefficients; 0.74 and 0.86, respectively). The saliva tapeworm test was capable of identifying the presence of one or more tapeworms with 83% sensitivity and 85% specificity. Importantly, no high-burden (more than 20 tapeworms) horses were misdiagnosed. The saliva tapeworm test has statistical accuracy for detecting tapeworm burdens in horses with 83% sensitivity and 85% specificity, similar to those of the serologic ELISA (85% and 78%, respectively). © 2016 American Society for Veterinary Clinical Pathology.

  7. Dogs and intestinal parasites: a public health problem.

    PubMed

    Seah, S K; Hucal, G; Law, C

    1975-05-17

    The stools of 239 stray dogs were examined for intestinal parasites. Of the helminths found, Toxocara canis (43.5%), tapeworms (25.5%), Ascaris species (21.3%) and hookworms (12.5%) were the commonest. Of the protozoans found, Isospora species and Entamoeba coli were the most prevalent. An unusual feature of the present study was the finding of Ascaris species. The importance of the high prevalence of intestinal parasites in dogs, the close contact of humans with dogs' excreta and the possible role of this environmental pollution in the spread of human disease are discussed.

  8. Multiplex PCR for Differential Identification of Broad Tapeworms (Cestoda: Diphyllobothrium) Infecting Humans▿

    PubMed Central

    Wicht, Barbara; Yanagida, Tetsuya; Scholz, Tomáš; Ito, Akira; Jiménez, Juan A.; Brabec, Jan

    2010-01-01

    The specific identification of broad tapeworms (genus Diphyllobothrium) infecting humans is very difficult to perform by morphological observation. Molecular analysis by PCR and sequencing represents the only reliable tool to date to identify these parasites to the species level. Due to the recent spread of human diphyllobothriosis in several countries, a correct diagnosis has become crucial to better understand the distribution and the life cycle of human-infecting species as well as to prevent the introduction of parasites to disease-free water systems. Nevertheless, PCR and sequencing, although highly precise, are too complicated, long, and expensive to be employed in medical laboratories for routine diagnostics. In the present study we optimized a cheap and rapid molecular test for the differential identification of the most common Diphyllobothrium species infecting humans (D. latum, D. dendriticum, D. nihonkaiense, and D. pacificum), based on a multiplex PCR with the cytochrome c oxidase subunit 1 gene of mitochondrial DNA. PMID:20592146

  9. Anthelmintic efficacy of Clerodendrum viscosum on fowl tapeworm Raillietina tetragona.

    PubMed

    Nandi, Suranjana; Ukil, Bidisha; Roy, Saptarshi; Kundu, Suman; Lyndem, Larisha Mawkhlieng

    2017-12-01

    Clerodendrum viscosum Vent. (Verbenaceae) is a shrub, widely used amongst the natives of India against various diseases. Crude extract of the plant was tested in vitro on a tapeworm Raillietina tetragona Molin (Davaineidae) to evaluate its potential anthelmintic efficacy and ultrastructural changes in the parasite. Parasites were exposed to different concentrations of ethanolic leaf extract (10-80 mg/mL) and praziquantel (0.0005-0.005 mg/mL) and incubated in phosphate-buffered saline (PBS). The pH was 7.4 at 37 °C, while one set of worms was incubated only with PBS as a control. Permanent immobilization of worms was determined visually when no motility occurred on physically disturbing them. The parasites exposed to high concentrations of leaf extract and praziquantel treatments were processed for histological and electron microscopic studies, as these concentrations took the least time for paralysis and death to occur. With an increase in the concentration of the leaf extract from 10 to 80 mg/mL and praziquantel from 0.0005 to 0.005 mg/mL, the time for the onset of paralysis and death was shortened. The treated parasites lost their spontaneous movement rapidly followed by death. Electron microscopic observations revealed disruptions in the tegument and parenchymal layer, accompanied by deformities in cell organelles. Extensive structural alterations in the tegument indicate that the plant-derived components cause permeability changes in the parasite leading to paralysis and subsequent death. These observations suggest that phytochemicals present in C. viscosum have vermifugal or vermicidal activity, and thus may be exploited as alternative chemotherapeutic agents.

  10. Evolutionary implications of the adaptation to different immune systems in a parasite with a complex life cycle

    PubMed Central

    Hammerschmidt, Katrin; Kurtz, Joachim

    2005-01-01

    Many diseases are caused by parasites with complex life cycles that involve several hosts. If parasites cope better with only one of the different types of immune systems of their host species, we might expect a trade-off in parasite performance in the different hosts, that likely influences the evolution of virulence. We tested this hypothesis in a naturally co-evolving host–parasite system consisting of the tapeworm Schistocephalus solidus and its intermediate hosts, a copepod, Macrocyclops albidus, and the three-spined stickleback Gasterosteus aculeatus. We did not find a trade-off between infection success in the two hosts. Rather, tapeworms seem to trade-off adaptation towards different parts of their hosts' immune systems. Worm sibships that performed better in the invertebrate host also seem to be able to evade detection by the fish innate defence systems, i.e. induce lower levels of activation of innate immune components. These worm variants were less harmful for the fish host likely due to reduced costs of an activated innate immune system. These findings substantiate the impact of both hosts' immune systems on parasite performance and virulence. PMID:16271977

  11. 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

  12. Proteocephalid tapeworms (Cestoda: Onchoproteocephalidea) of loaches (Cobitoidea): Evidence for monophyly and high endemism of parasites in the Far East.

    PubMed

    Scholz, Tomáš; de Chambrier, Alain; Shimazu, Takeshi; Ermolenko, Alexey; Waeschenbach, Andrea

    2017-02-01

    The parasite fauna of loaches (Cypriniformes: Cobitoidea), a group of small bottom-dwelling freshwater fishes with a mostly Eurasian distribution, remains a largely unknown quantity. Here we revise the taxonomy of tapeworms of the genus Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidae) that had been found in loaches from the Palaearctic Region (Central Europe, Japan and Russia [Primorsky Region]). Molecular phylogenetic analysis based on two nuclear (ssr- and lsrDNA) and two mitochondrial genes (cox1 and rrnL) revealed a monophyletic group consisting of four valid species nesting within the Proteocephalus-aggregate: (i) Proteocephalus sagittus (Grimm, 1872) from Barbatula barbatula (Europe, Russia and Tajikistan), (ii) Proteocephalus demshini n. sp. from Barbatula toni (Russian Far East - Primorsky Region), (iii) Proteocephalus midoriensis Shimazu, 1990 from Lefua echigonia (Japan) and L. costata (Russia) (new host and geographical record), and (iv) Proteocephalus misgurni n. sp. from Misgurnus anguillicaudatus (Russia; Primorsky Region). Proteocephalus sagittus and P. demshini, and P. midoriensis and P. misgurni were recovered as sister taxa, respectively. Proteocephalus sagittus and P. demshini are characterized by having proglottids that are wider than long, an elongate to pyriform cirrus-sac and the vitelline follicles that form wide lateral bands. Proteocephalus midoriensis and P. misgurni are characterized by having proglottids that are more elongate and an ovoid to almost spherical cirrus-sac and the vitelline follicles forming narrow lateral bands. Proteocephalus demshini differs from P. sagittus in the posterolateral extent of the vitelline follicles, whereas P. misgurni can be distinguished from P. midoriensis mainly by the relative size of the ovary, posterior extent of the vitelline follicles and width of the scolex. Unlike most species of the Proteocephalus-aggregate that possess an apical sucker, all species from loaches are devoid of any

  13. The Hamster Model for Identification of Specific Antigens of Taenia solium Tapeworms

    PubMed Central

    Ochoa-Sánchez, Alicia; Jiménez, Lucía; Landa, Abraham

    2011-01-01

    Humans acquire taeniasis by ingesting pork meat infected with Taenia solium cysticerci, which are the only definitive hosts of the adult stage (tapeworm) and responsible for transmitting the human and porcine cysticercosis. Hence, detection of human tapeworm carriers is a key element in the development of viable strategies to control the disease. This paper presents the identification of specific antigens using sera from hamsters infected with T. solium tapeworms analyzed by western blot assay with crude extracts (CEs) and excretion-secretion antigens (E/S Ag) obtained from T. solium cysticerci and tapeworms and extracts from other helminthes as controls. The hamster sera infected with T. solium tapeworms recognized specific bands of 72, 48, 36, and 24 kDa, in percentages of 81, 81, 90, and 88%, respectively, using the T. solium tapeworms E/S Ag. The antigens recognized by these hamster sera could be candidates to improve diagnosis of human T. solium taeniasis. PMID:22253530

  14. Hepatozoon parasites (Apicomplexa: Adeleorina) in bats.

    PubMed

    Pinto, C Miguel; Helgen, Kristofer M; Fleischer, Robert C; Perkins, Susan L

    2013-08-01

    We provide the first evidence of Hepatozoon parasites infecting bats. We sequenced a short fragment of the 18S rRNA gene (~600 base pairs) of Hepatozoon parasites from 3 Hipposideros cervinus bats from Borneo. Phylogenies inferred by model-based methods place these Hepatozoon within a clade formed by parasites of reptiles, rodents, and marsupials. We discuss the scenario that bats might be common hosts of Hepatozoon.

  15. Dogs and intestinal parasites: a public health problem.

    PubMed Central

    Seah, S. K.; Hucal, G.; Law, C.

    1975-01-01

    The stools of 239 stray dogs were examined for intestinal parasites. Of the helminths found, Toxocara canis (43.5%), tapeworms (25.5%), Ascaris species (21.3%) and hookworms (12.5%) were the commonest. Of the protozoans found, Isospora species and Entamoeba coli were the most prevalent. An unusual feature of the present study was the finding of Ascaris species. The importance of the high prevalence of intestinal parasites in dogs, the close contact of humans with dogs' excreta and the possible role of this environmental pollution in the spread of human disease are discussed. PMID:1125888

  16. Miscellaneous parasitic diseases

    USGS Publications Warehouse

    Cole, Rebecca A.; Friend, M.

    1999-01-01

    Free-ranging wild birds are afflicted with numerous other parasites that occasionally cause illness and death. Some of these parasites, such as two of the trematodes or flukes highlighted below, can cause major die-offs. This section about parasitic diseases concludes with descriptions of some additional parasites that field biologists may encounter in wild birds. This listing is by no means complete and it is intended only to increase awareness of the diversity of types of parasites that might be encountered during examinations of wild birds. One should not assume that the parasites found during the examination of bird carcasses caused their death. Because parasites of birds vary greatly in size from a protozoa of a few microns in length to tapeworms of several inches in length and because they can be found in virtually all tissues, body cavities and other locations within the bird, the observation of the parasites will depend on their visibility and the thoroughness of the examination. Therefore, it is generally beneficial to submit bird carcasses to qualified disease diagnostic laboratories to obtain evaluations of the significance of endoparasites or of ectoparasites. The methods that are used to preserve the carcass, tissues, or other specimens can enhance or compromise the ability of specialists to identify the parasite to species, and even to genera, in some instances. Therefore, whenever possible, it is best to contact the diagnostic laboratory that will receive the specimens and obtain instructions for collecting, preserving, and shipping field samples (See Chapters 2 and 3).

  17. Biotransformation of anthelmintics and the activity of drug-metabolizing enzymes in the tapeworm Moniezia expansa.

    PubMed

    Prchal, Lukáš; Bártíková, Hana; Bečanová, Aneta; Jirásko, Robert; Vokřál, Ivan; Stuchlíková, Lucie; Skálová, Lenka; Kubíček, Vladimír; Lamka, Jiří; Trejtnar, František; Szotáková, Barbora

    2015-04-01

    The sheep tapeworm Moniezia expansa is very common parasite, which affects ruminants such as sheep, goats as well as other species. The benzimidazole anthelmintics albendazole (ABZ), flubendazole (FLU) and mebendazole (MBZ) are often used to treat the infection. The drug-metabolizing enzymes of helminths may alter the potency of anthelmintic treatment. The aim of our study was to assess the activity of the main drug-metabolizing enzymes and evaluate the metabolism of selected anthelmintics (ABZ, MBZ and FLU) in M. expansa. Activities of biotransformation enzymes were determined in subcellular fractions. Metabolites of the anthelmintics were detected and identified using high performance liquid chromatography/ultra-violet/VIS/fluorescence or ultra-high performance liquid chromatography/mass spectrometry. Reduction of MBZ, FLU and oxidation of ABZ were proved as well as activities of various metabolizing enzymes. Despite the fact that the conjugation enzymes glutathione S-transferase, UDP-glucuronosyl transferase and UDP-glucosyl transferase were active in vitro, no conjugated metabolites of anthelmintics were identified either ex vivo or in vitro. The obtained results indicate that sheep tapeworm is able to deactivate the administered anthelmintics, and thus protects itself against their action.

  18. Molecular insights into a tetraspanin in the hydatid tapeworm Echinococcus granulosus.

    PubMed

    Hu, Dandan; Song, Xingju; Xie, Yue; Zhong, Xiuqin; Wang, Ning; Zheng, Yu; Gu, Xiaobin; Wang, Tao; Peng, Xuerong; Yang, Guangyou

    2015-06-10

    Cystic echinococcosis (hydatid disease), caused by the tapeworm Echinococcus granulosus (class Cestoda; family Taeniidae), is a neglected tropical disease that results in morbidity and mortality in millions of humans, as well as in huge economic losses in the livestock industry globally. Proteins from the tetraspanin family in parasites have recently become regarded as crucial molecules in interaction with hosts in parasitism and are therefore suitable for the development of vaccines and diagnostic agents. However, no information is available to date on E. granulosus tetraspanin. In this study, a uroplakin-I-like tetraspanin (Eg-TSP1) of E. granulosus was cloned and expressed in E. coli. The immunolocalization of Eg-TSP1 in different life stages of E. granulosus was determined using specific polyclonal antibody. The antibody and cytokine profiles of mice that immunized with recombinant Eg-TSP1 (rEg-TSP1) were measured for the immunogenicity analysis of this protein. Additionally, we use RNA interference method to explore the biological function of Eg-TSP1 in larva of E. granulosus. Immunofluorescence analysis showed that endogenous Eg-TSP1 mainly localized in the tegument of larvae and adults. Significantly elevated levels of antibodies IgG1 and IgG2a and of cytokines IFN-γ and IL-12 were observed in the sera of mice after immunization with rEg-TSP1, suggesting a typical T helper (Th)1-mediated immune response elicited by rEg-TSP1. On further probing the role of Eg-TSP1 in E. granulosus by RNA interference, we found that a thinner tegmental distal cytoplasm was induced in protoscoleces treated with siRNA-132 compared to controls. This is the first report characterizing a tetraspanin from the tapeworm E. granulosus. Our results suggest that Eg-TSP1 is associated with biogenesis of the tegument and maintenance of structural integrity of E. granulosus and could therefore be a candidate intervention target for control of hydatid disease.

  19. Parasite transfer from crustacean to fish hosts in the Lübeck Bight, SW Baltic Sea

    NASA Astrophysics Data System (ADS)

    Zander, C. D.; Groenewold, S.; Strohbach, U.

    1994-03-01

    Four helminth parasites out of 19 species found in the Lübeck Bight, Baltic Sea, were chosen for investigations on the transfer from invertebrate to small-sized fish hosts: larvae of the tapeworms Schistocephalus sp. and Bothriocephalus sp. (Cestoda) living in planktonic copepods as primary hosts; Podocotyle atomon (Digenea) and Hysterothylacium sp. (Nematoda) were found in benthic crustaceans, especially Gammarus spp. These hosts were the prey of 3 gobiid fishes, Gobiusculus flavescens (feeding mainly on plankton), Pomatoschistus minutus (preferring benthos), and P. pictus (feeding more on plankton than benthos). Because the fishes selected smaller sizes of crustaceans, they ingested all stages of the copepods but only the smaller-sized groups of gammarids which were often less infested by parasites. In order to evaluate the probability for a fish to be parasitized by a helminth, an infestation potential index (IP) was calculated. Podocotyle atomon and Hysterothylacium sp. revealed an IP which was far lower in gobies than expected when the prevalences of the previous hosts were taken into consideration. The IP of tapeworm larvae was mainly influenced by the feeding pressure of the gobiid predators, which might change with developmental stage and season. It is concluded that parasite transfer to the next host decreases when sizes of prey and predator differ only moderately. This mechanism can reduce the numbers of parasites transferred to less suitable or wrong hosts.

  20. Phylogeny and micro-habitats utilized by lizards determine the composition of their endoparasites in the semiarid Caatinga of Northeast Brazil.

    PubMed

    Brito, S V; Corso, G; Almeida, A M; Ferreira, F S; Almeida, W O; Anjos, L A; Mesquita, D O; Vasconcellos, A

    2014-11-01

    Trophic networks can have architectonic configurations influenced by historical and ecological factors. The objective of this study was to analyze the architecture of networks between lizards, their endoparasites, diet, and micro-habitat, aiming to understand which factors exert an influence on the composition of the species of parasites. All networks showed a compartmentalized pattern. There was a positive relation between diet and the diversity of endoparasites. Our analyses also demonstrated that phylogeny and the use of micro-habitat influenced the composition of species of endoparasites and diet pattern of lizards. The principal factor that explained the modularity of the network was the foraging strategy, with segregation between the "active foragers" and "sit-and-wait" lizards. Our analyses also demonstrated that historical (phylogeny) and ecological factors (use of micro-habitat by the lizards) influenced the composition of parasite communities. These results corroborate other studies with ectoparasites, which indicate phylogeny and micro-habitat as determinants in the composition of parasitic fauna. The influence of phylogeny can be the result of coevolution between parasites and lizards in the Caatinga, and the influence of micro-habitat should be a result of adaptations of species of parasites to occupy the same categories of micro-habitats as hosts, thus favoring contagion.

  1. Phylogenetic congruence of parasitic smut fungi (Anthracoidea, Anthracoideaceae) and their host plants (Carex, Cyperaceae): Cospeciation or host-shift speciation?

    PubMed

    Escudero, Marcial

    2015-07-01

    • Fahrenholz's rule states that common ancestors of extant parasites were parasites of the common ancestors of extant hosts. Consequently, parasite phylogeny should mirror host phylogeny. The smut fungi genus Anthracoidea (Anthracoideaceae) is mainly hosted by species of the genus Carex (Cyperaceae). Whether smut fungi phylogeny mirrors sedge phylogeny is still under debate.• The nuclear large subunit DNA region (LSU; 57 accessions) from 31 Anthracoidea species and the ITS, ETS, and trnL-F spacer-trnL intron complex from 41 Carex species were used to infer the phylogenetic history of parasites and their hosts using a maximum likelihood approach. Event-based and distance-based cophylogenetic methods were used to test the hypothesis of whether the phylogeny of smut fungi from the genus Anthracoidea matches the phylogeny of the sedge Carex species they host.• Cophylogenetic reconstructions taking into account phylogenetic uncertainties based on event-based analyses demonstrated that the Anthracoidea phylogeny has significant topological congruence with the phylogeny of their Carex hosts. A distance-based test was also significant; therefore, the phylogenies of Anthracoide and Carex are partially congruent.• The phylogenetic congruence of Anthracoidea and Carex is partially based on smut fungi species being preferentially hosted by closely related sedges (host conservatism). In addition, many different events rather than only codivergence events are inferred. All of this evidence suggests that host-shift speciation rather than cospeciation seems to explain the cophylogenetic patterns of Anthracoidea and Carex. © 2015 Botanical Society of America, Inc.

  2. Ichthyophonus parasite phylogeny based on ITS rDNA structure prediction and alignment identifies six clades, with a single dominant marine type

    USGS Publications Warehouse

    Gregg, Jacob; Thompson, Rachel L.; Purcell, Maureen; Friedman, Carolyn S.; Hershberger, Paul

    2016-01-01

    Despite their widespread, global impact in both wild and cultured fishes, little is known of the diversity, transmission patterns, and phylogeography of parasites generally identified as Ichthyophonus. This study constructed a phylogeny based on the structural alignment of internal transcribed spacer (ITS) rDNA sequences to compare Ichthyophonus isolates from fish hosts in the Atlantic and Pacific oceans, and several rivers and aquaculture sites in North America, Europe, and Japan. Structure of the Ichthyophonus ITS1–5.8S–ITS2 transcript exhibited several homologies with other eukaryotes, and 6 distinct clades were identified within Ichthyophonus. A single clade contained a majority (71 of 98) of parasite isolations. This ubiquitous Ichthyophonus type occurred in 13 marine and anadromous hosts and was associated with epizootics in Atlantic herring, Chinook salmon, and American shad. A second clade contained all isolates from aquaculture, despite great geographic separation of the freshwater hosts. Each of the 4 remaining clades contained isolates from single host species. This study is the first to evaluate the genetic relationships among Ichthyophonus species across a significant portion of their host and geographic range. Additionally, parasite infection prevalence is reported in 16 fish species.

  3. Helminthic parasites and seizures.

    PubMed

    Garcia, Hector H; Modi, Manish

    2008-08-01

    A large number of helminthic parasites are known to involve the central nervous system (CNS) and produce neurologic symptoms including seizures and epilepsy. Taenia solium (the pork tapeworm) is perhaps most widely prevalent and well known for its association with seizures and epilepsy. Many of the other helminthic disorders have fairly restricted geographic predilections and their occurrence in much of the remaining world is limited to rare cases among travelers and immigrants. Nonetheless, knowledge about the helminthic disorders, the life cycle of their causative agents, and their clinical manifestations and diagnostic features are important in order to recognize them.

  4. A three-genome phylogeny of malaria parasites (Plasmodium and closely related genera): evolution of life-history traits and host switches.

    PubMed

    Martinsen, Ellen S; Perkins, Susan L; Schall, Jos J

    2008-04-01

    Phylogenetic analysis of genomic data allows insights into the evolutionary history of pathogens, especially the events leading to host switching and diversification, as well as alterations of the life cycle (life-history traits). Hundreds, perhaps thousands, of malaria parasite species exploit squamate reptiles, birds, and mammals as vertebrate hosts as well as many genera of dipteran vectors, but the evolutionary and ecological events that led to this diversification and success remain unresolved. For a century, systematic parasitologists classified malaria parasites into genera based on morphology, life cycle, and vertebrate and insect host taxa. Molecular systematic studies based on single genes challenged the phylogenetic significance of these characters, but several significant nodes were not well supported. We recovered the first well resolved large phylogeny of Plasmodium and related haemosporidian parasites using sequence data for four genes from the parasites' three genomes by combining all data, correcting for variable rates of substitution by gene and site, and using both Bayesian and maximum parsimony analyses. Major clades are associated with vector shifts into different dipteran families, with other characters used in traditional parasitological studies, such as morphology and life-history traits, having variable phylogenetic significance. The common parasites of birds now placed into the genus Haemoproteus are found in two divergent clades, and the genus Plasmodium is paraphyletic with respect to Hepatocystis, a group of species with very different life history and morphology. The Plasmodium of mammal hosts form a well supported clade (including Plasmodium falciparum, the most important human malaria parasite), and this clade is associated with specialization to Anopheles mosquito vectors. The Plasmodium of birds and squamate reptiles all fall within a single clade, with evidence for repeated switching between birds and squamate hosts.

  5. Molecular phylogeny of anoplocephalid tapeworms (Cestoda: Anoplocephalidae) infecting humans and non-human primates.

    PubMed

    Doležalová, Jana; Vallo, Peter; Petrželková, Klára J; Foitová, Ivona; Nurcahyo, Wisnu; Mudakikwa, Antoine; Hashimoto, Chie; Jirků, Milan; Lukeš, Julius; Scholz, Tomáš; Modrý, David

    2015-09-01

    Anoplocephalid tapeworms of the genus Bertiella Stiles and Hassall, 1902 and Anoplocephala Blanchard, 1848, found in the Asian, African and American non-human primates are presumed to sporadic ape-to-man transmissions. Variable nuclear (5.8S-ITS2; 28S rRNA) and mitochondrial genes (cox1; nad1) of isolates of anoplocephalids originating from different primates (Callicebus oenanthe, Gorilla beringei, Gorilla gorilla, Pan troglodytes and Pongo abelii) and humans from various regions (South America, Africa, South-East Asia) were sequenced. In most analyses, Bertiella formed a monophyletic group within the subfamily Anoplocephalinae, however, the 28S rRNA sequence-based analysis indicated paraphyletic relationship between Bertiella from primates and Australian marsupials and rodents, which should thus be regarded as different taxa. Moreover, isolate determined as Anoplocephala cf. gorillae from mountain gorilla clustered within the Bertiella clade from primates. This either indicates that A. gorillae deserves to be included into the genus Bertiella, or, that an unknown Bertiella species infects also mountain gorillas. The analyses allowed the genetic differentiation of the isolates, albeit with no obvious geographical or host-related patterns. The unexpected genetic diversity of the isolates studied suggests the existence of several Bertiella species in primates and human and calls for revision of the whole group, based both on molecular and morphological data.

  6. Bothriocephalidean tapeworms (Cestoda) from the blackfish, Centrolophus niger (Perciformes: Centrolophidae).

    PubMed

    Kuchta, Roman; Scholz, Tomás; Brabec, Jan; Jirsová, Dagmar; Gustinelli, Andrea

    2008-06-01

    Bothriocephalidean tapeworms parasitic in the blackfish, Centrolophus niger (Gmelin) (Perciformes: Centrolophidae), are redescribed on the basis of the evaluation of freshly collected specimens and museum material. This evaluation enabled us to supplement species diagnoses by new morphological characters of potential use for phylogenetic analyses, including the data from scanning electron microscopical observations, and to provide a key to identification of the following four species occurring in this fish: Amphicotyle heteropleura (Diesing, 1850); Milanella familiaris Kuchta et Scholz, 2008 (both Triaenophoridae); Bothriocotyle solinosomum Ariola, 1900; and Echinophallus wageneri (Monticelli, 1890) (both Echinophallidae). Large spiniform microtriches were observed on the surface of the posterodorsal margin of segments of B. solinosomum, E. wageneri and M. familiaris. The invalidity of Atelemerus Guiart, 1935, first proposed by Bray et al. (1994), is supported by the present data and its type species, A. acanthodes Guiart, 1935, is newly synonymised with E. wageneri.

  7. 9 CFR 311.23 - Tapeworm cysts (cysticercus bovis) in cattle.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Tapeworm cysts (cysticercus bovis) in cattle. 311.23 Section 311.23 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... PARTS § 311.23 Tapeworm cysts (cysticercus bovis) in cattle. (a) Except as provided in paragraph (b) of...

  8. 9 CFR 311.23 - Tapeworm cysts (cysticercus bovis) in cattle.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Tapeworm cysts (cysticercus bovis) in cattle. 311.23 Section 311.23 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... PARTS § 311.23 Tapeworm cysts (cysticercus bovis) in cattle. (a) Except as provided in paragraph (b) of...

  9. 9 CFR 311.23 - Tapeworm cysts (cysticercus bovis) in cattle.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Tapeworm cysts (cysticercus bovis) in cattle. 311.23 Section 311.23 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... PARTS § 311.23 Tapeworm cysts (cysticercus bovis) in cattle. (a) Except as provided in paragraph (b) of...

  10. 9 CFR 311.23 - Tapeworm cysts (cysticercus bovis) in cattle.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Tapeworm cysts (cysticercus bovis) in cattle. 311.23 Section 311.23 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... PARTS § 311.23 Tapeworm cysts (cysticercus bovis) in cattle. (a) Except as provided in paragraph (b) of...

  11. What are the Mechanisms Behind a Parasite-Induced Decline in Nestmate Recognition in Ants?

    PubMed

    Beros, Sara; Foitzik, Susanne; Menzel, Florian

    2017-09-01

    Social insects have developed sophisticated recognition skills to defend their nests against intruders. They do this by aggressively discriminating against non-nestmates with deviant cuticular hydrocarbon (CHC) signatures. Studying nestmate recognition can be challenging as individual insects do not only vary in their discriminatory abilities, but also in their motivation to behave aggressively. To disentangle the influence of signaling and behavioral motivation on nestmate recognition, we investigated the ant Temnothorax nylanderi, where the presence of tapeworm-infected nestmates leads to reduced nestmate recognition among uninfected workers. The parasite-induced decline in nestmate recognition could be caused by higher intra-colonial cue diversity as tapeworm-infected workers are known to exhibit a modified hydrocarbon signature. This in turn may broaden the neuronal template of their nestmates, leading to a higher tolerance towards alien conspecifics. To test this hypothesis, we exchanged infected ants between colonies and analyzed their impact on CHC profiles of uninfected workers. We demonstrate that despite frequent grooming, which should promote the transfer of recognition cues, CHC profiles of uninfected workers neither changed in the presence of tapeworm-infected ants, nor did it increase cue diversity among uninfected nestmates within or between colonies. However, CHC profiles were systematically affected by the removal of nestmates and addition of non-nestmates, independently from the ants' infection status. For example, when non-nestmates were present workers expressed more dimethyl alkanes and higher overall CHC quantities, possibly to achieve a better distinction from non-nestmates. Workers showed clear task-specific profiles with tapeworm-infected workers resembling more closely young nurses than older foragers. Our results show that the parasite-induced decline in nestmate recognition is not due to increased recognition cue diversity or altered CHC

  12. Topological congruence between phylogenies of Anacanthorus spp. (Monogenea: Dactylogyridae) and their Characiformes (Actinopterygii) hosts: A case of host-parasite cospeciation

    PubMed Central

    Fabrin, Thomaz M. C.; Gasques, Luciano S.; Prioli, Sônia M. A. P.; Balbuena, Juan A.; Prioli, Alberto J.; Takemoto, Ricardo M.

    2018-01-01

    Cophylogenetic studies aim at testing specific hypotheses to understand the nature of coevolving associations between sets of organisms, such as host and parasites. Monogeneans and their hosts provide and interesting platform for these studies due to their high host specificity. In this context, the objective of the present study was to establish whether the relationship between Anacanthorus spp. with their hosts from the upper Paraná River and its tributaries can be explained by means of cospeciation processes. Nine fish species and 14 monogenean species, most of them host specific, were studied. Partial DNA sequences of the genes RAG1, 16S and COI of the fish hosts and of the genes ITS2, COI and 5.8S of the parasite species were used for phylogenetic reconstruction. Maximum likelihood phylogenetic trees of the host and parasite species were built and used for analyses of topological congruence with PACo and ParaFit. The program Jane was used to estimate the nature of cospeciation events. The comparison of the two phylogenies revealed high topological congruence between them. Both PACo and ParaFit supported the hypothesis of global cospeciation. Results from Jane pointed to duplications as the most frequent coevolutionary event, followed by cospeciation, whereas duplications followed by host-switching were the least common event in Anacanthorus spp. studied. Host-sharing (spreading) was also identified but only between congeneric host species. PMID:29538463

  13. Topological congruence between phylogenies of Anacanthorus spp. (Monogenea: Dactylogyridae) and their Characiformes (Actinopterygii) hosts: A case of host-parasite cospeciation.

    PubMed

    da Graça, Rodrigo J; Fabrin, Thomaz M C; Gasques, Luciano S; Prioli, Sônia M A P; Balbuena, Juan A; Prioli, Alberto J; Takemoto, Ricardo M

    2018-01-01

    Cophylogenetic studies aim at testing specific hypotheses to understand the nature of coevolving associations between sets of organisms, such as host and parasites. Monogeneans and their hosts provide and interesting platform for these studies due to their high host specificity. In this context, the objective of the present study was to establish whether the relationship between Anacanthorus spp. with their hosts from the upper Paraná River and its tributaries can be explained by means of cospeciation processes. Nine fish species and 14 monogenean species, most of them host specific, were studied. Partial DNA sequences of the genes RAG1, 16S and COI of the fish hosts and of the genes ITS2, COI and 5.8S of the parasite species were used for phylogenetic reconstruction. Maximum likelihood phylogenetic trees of the host and parasite species were built and used for analyses of topological congruence with PACo and ParaFit. The program Jane was used to estimate the nature of cospeciation events. The comparison of the two phylogenies revealed high topological congruence between them. Both PACo and ParaFit supported the hypothesis of global cospeciation. Results from Jane pointed to duplications as the most frequent coevolutionary event, followed by cospeciation, whereas duplications followed by host-switching were the least common event in Anacanthorus spp. studied. Host-sharing (spreading) was also identified but only between congeneric host species.

  14. Multiple isotope analyses of the pike tapeworm Triaenophorus nodulosus reveal peculiarities in consumer-diet discrimination patterns.

    PubMed

    Behrmann-Godel, J; Yohannes, E

    2015-03-01

    Previous studies of dietary isotope discrimination have led to the general expectation that a consumer will exhibit enriched stable isotope levels relative to its diet. Parasite-host systems are specific consumer-diet pairs in which the consumer (parasite) feeds exclusively on one dietary source: host tissue. However, the small numbers of studies previously carried out on isotopic discrimination in parasite-host (ΔXP-HT) systems have yielded controversial results, showing some parasites to be isotopically depleted relative to their food source, while others are enriched or in equilibrium with their hosts. Although the mechanism for these deviations from expectations remains to be understood, possible influences of specific feeding niche or selection for only a few nutritional components by the parasite are discussed. ΔXP-HT for multiple isotopes (δ13C, δ15N, δ34S) were measured in the pike tapeworm Triaenophorus nodulosus and two of its life-cycle fish hosts, perch Perca fluviatilis and pike Esox lucius, within which T. nodulosus occupies different feeding locations. Variability in the value of ΔXP-HT calculated for the parasite and its different hosts indicates an influence of feeding location on isotopic discrimination. In perch liver ΔXP-HT was relatively more negative for all three stable isotopes. In pike gut ΔXP-HT was more positive for δ13C, as expected in conventional consumer-diet systems. For parasites feeding on pike gut, however, the δ15N and δ34S isotope values were comparable with those of the host. We discuss potential causes of these deviations from expectations, including the effect of specific parasite feeding niches, and conclude that ΔXP-HT should be critically evaluated for trophic interactions between parasite and host before general patterns are assumed.

  15. Host-parasite coevolution: comparative evidence for covariation of life history traits in primates and oxyurid parasites.

    PubMed Central

    Sorci, G; Morand, S; Hugot, J P

    1997-01-01

    The environmental factors that drive the evolution of parasite life histories are mostly unknown. Given that hosts provide the principal environmental features parasites have to deal with, and given that these features (such as resource availability and immune responses) are well characterized by the life history of the host, we may expect natural selection to result in covariation between parasite and host life histories. Moreover, some parasites show a high degree of host specificity, and cladistic analyses have shown that host and parasite phylogenies can be highly congruent. These considerations suggest that parasite and host life histories may covary. The central argument in the theory of life history evolution concerns the existence of trade-offs between traits. For parasitic nematodes it has been shown that larger body sizes induce higher fecundity, but this is achieved at the expense of delayed maturity. As high adult mortality would select for reduced age at maturity, the selective benefit of increased fecundity is expressed only if adult mortality is low. Parasite adult mortality may depend on a number of factors, including host longevity. Here we tested the hypothesis concerning the positive covariation between parasite body size (which reflects parasite longevity) and host longevity. To achieve this goal, we used the association between the pinworms (Oxyuridae, Nematoda) and their primate hosts. Oxyurids are highly host specific and are supposed to be involved in a coevolutionary process with their hosts. We found that female parasite body length was positively correlated with host longevity after correcting for phylogeny and host body mass. Conversely, male parasite body length and host longevity were not correlated. These results confirm that host longevity may represent a constraint on the evolution of body size in oxyurids, at least in females. The discrepancy between female and male oxyurids is likely to depend on the particular mode of

  16. Parasitism by larval tapeworms genus Spirometra in South American amphibians and reptiles: new records from Brazil and Uruguay, and a review of current knowledge in the region.

    PubMed

    Oda, Fabrício H; Borteiro, Claudio; da Graça, Rodrigo J; Tavares, Luiz Eduardo R; Crampet, Alejandro; Guerra, Vinicius; Lima, Flávia S; Bellay, Sybelle; Karling, Letícia C; Castro, Oscar; Takemoto, Ricardo M; Pavanelli, Gilberto C

    2016-12-01

    Spargana are plerocercoid larvae of cestode tapeworms of the genus Spirometra, Family Diphyllobothriidae, parasitic to frogs, reptiles, birds and mammals. This parasitic disease in humans can be transmitted through the use and consumption of amphibians and reptiles. The available knowledge about Spirometra in South America is scarce, and there are only a few reports on the occurrence of sparganum in amphibians and reptiles, many of them published in old papers not easily available to researchers. In this work we present a review on this topic, provide new records in two species of amphibians and 7 species of reptiles from Brazil and Uruguay respectively. We also summarize current knowledge of Spirometra in the continent, along with an updated of host taxonomy. We could gather from the literature a total of 15 studies about amphibian and reptile hosts, published between 1850 and 2016, corresponding to 43 case reports, mostly from Brazil (29) and Uruguay (8), Argentina (3), Peru (2), and Venezuela (1); the majority of them related to reptiles (five lizards and 26 snake species), and 14 corresponded to amphibians (9 anurans). Plerocercoid larvae were located in different organs of the hosts, such as subcutaneous tissue, coelomic cavity, peritoneum, and musculature. The importance of amphibians and reptiles in the transmission of the disease to humans in South America is discussed. Relevant issues to be studied in the near future are the taxonomic characterization of Spirometra in the region and the biological risk of reptile meat for aboriginal and other rural communities. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Predicting what helminth parasites a fish species should have using Parasite Co-occurrence Modeler (PaCo)

    USGS Publications Warehouse

    Strona, Giovanni; Lafferty, Kevin D.

    2013-01-01

    Fish pathologists are often interested in which parasites would likely be present in a particular host. Parasite Co-occurrence Modeler (PaCo) is a tool for identifying a list of parasites known from fish species that are similar ecologically, phylogenetically, and geographically to the host of interest. PaCo uses data from FishBase (maximum length, growth rate, life span, age at maturity, trophic level, phylogeny, and biogeography) to estimate compatibility between a target host and parasite species–genera from the major helminth groups (Acanthocephala, Cestoda, Monogenea, Nematoda, and Trematoda). Users can include any combination of host attributes in a model. These unique features make PaCo an innovative tool for addressing both theoretical and applied questions in parasitology. In addition to predicting the occurrence of parasites, PaCo can be used to investigate how host characteristics shape parasite communities. To test the performance of the PaCo algorithm, we created 12,400 parasite lists by applying any possible combination of model parameters (248) to 50 fish hosts. We then measured the relative importance of each parameter by assessing their frequency in the best models for each host. Host phylogeny and host geography were identified as the most important factors, with both present in 88% of the best models. Habitat (64%) was identified in more than half of the best models. Among ecological parameters, trophic level (41%) was the most relevant while life span (34%), growth rate (32%), maximum length (28%), and age at maturity (20%) were less commonly linked to best models. PaCo is free to use at www.purl.oclc.org/fishpest.

  18. Predicting what helminth parasites a fish species should have using Parasite Co-occurrence Modeler (PaCo).

    PubMed

    Strona, Giovanni; Lafferty, Kevin D

    2013-02-01

    Fish pathologists are often interested in which parasites would likely be present in a particular host. Parasite Co-occurrence Modeler (PaCo) is a tool for identifying a list of parasites known from fish species that are similar ecologically, phylogenetically, and geographically to the host of interest. PaCo uses data from FishBase (maximum length, growth rate, life span, age at maturity, trophic level, phylogeny, and biogeography) to estimate compatibility between a target host and parasite species-genera from the major helminth groups (Acanthocephala, Cestoda, Monogenea, Nematoda, and Trematoda). Users can include any combination of host attributes in a model. These unique features make PaCo an innovative tool for addressing both theoretical and applied questions in parasitology. In addition to predicting the occurrence of parasites, PaCo can be used to investigate how host characteristics shape parasite communities. To test the performance of the PaCo algorithm, we created 12,400 parasite lists by applying any possible combination of model parameters (248) to 50 fish hosts. We then measured the relative importance of each parameter by assessing their frequency in the best models for each host. Host phylogeny and host geography were identified as the most important factors, with both present in 88% of the best models. Habitat (64%) was identified in more than half of the best models. Among ecological parameters, trophic level (41%) was the most relevant while life span (34%), growth rate (32%), maximum length (28%), and age at maturity (20%) were less commonly linked to best models. PaCo is free to use at www.purl.oclc.org/fishpest.

  19. How to catch a parasite: Parasite Niche Modeler (PaNic) meets Fishbase

    USGS Publications Warehouse

    Strona, Giovanni; Lafferty, Kevin D.

    2012-01-01

    Parasite Niche Modeler (PaNic) is a free online software tool that suggests potential hosts for fish parasites. For a particular parasite species from the major helminth groups (Acanthocephala, Cestoda, Monogenea, Nematoda, Trematoda), PaNic takes data from known hosts (maximum body length, growth rate, life span, age at first maturity, trophic level, phylogeny, and biogeography) and hypothesizes similar fish species that might serve as hosts to that parasite. Users can give varying weights to host attributes and create custom models. In addition to suggesting plausible hosts (with varying degrees of confidence), the models indicate known host species that appear to be outliers in comparison to other known hosts. These unique features make PaNic an innovative tool for addressing both theoretical and applied questions in fish parasitology. PaNic can be accessed at .

  20. Parental effects on the larval performance of a tapeworm in its copepod first host.

    PubMed

    Benesh, D P

    2013-08-01

    Parents can influence the phenotype of their offspring through various mechanisms, besides the direct effect of heredity. Such parental effects are little explored in parasitic organisms, perhaps because in many parasites, per capita investment into offspring is low. I investigated whether parental identity, beyond direct genetic effects, could explain variation in the performance of the tapeworm Schistocephalus solidus in its first intermediate host, a copepod. I first determined that two breeding worms could be separated from one another after ~48 h of in vitro incubation and that the isolated worms continued producing outcrossed eggs, that is, rates self-fertilization did not increase after separation. Thus, from a breeding pair, two sets of genetically comparable eggs can be collected that have unambiguous parental identities. In an infection experiment, I found that the development of larval worms tended to vary between the two parental worms within breeding pairs, but infection success and growth rate in copepods did not. Accounting for this parental effect decreased the estimated heritability for development by nearly half. These results suggest that larval performance is not simply a function of a worm's genotype; who mothered or fathered an offspring can also affect offspring fitness, contradicting the perhaps naïve idea that parasites simply produce large quantities of uniformly low-quality offspring. © 2013 The Author. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  1. 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.

  2. The comparative ecology and biogeography of parasites

    PubMed Central

    Poulin, Robert; Krasnov, Boris R.; Mouillot, David; Thieltges, David W.

    2011-01-01

    Comparative ecology uses interspecific relationships among traits, while accounting for the phylogenetic non-independence of species, to uncover general evolutionary processes. Applied to biogeographic questions, it can be a powerful tool to explain the spatial distribution of organisms. Here, we review how comparative methods can elucidate biogeographic patterns and processes, using analyses of distributional data on parasites (fleas and helminths) as case studies. Methods exist to detect phylogenetic signals, i.e. the degree of phylogenetic dependence of a given character, and either to control for these signals in statistical analyses of interspecific data, or to measure their contribution to variance. Parasite–host interactions present a special case, as a given trait may be a parasite trait, a host trait or a property of the coevolved association rather than of one participant only. For some analyses, it is therefore necessary to correct simultaneously for both parasite phylogeny and host phylogeny, or to evaluate which has the greatest influence on trait expression. Using comparative approaches, we show that two fundamental properties of parasites, their niche breadth, i.e. host specificity, and the nature of their life cycle, can explain interspecific and latitudinal variation in the sizes of their geographical ranges, or rates of distance decay in the similarity of parasite communities. These findings illustrate the ways in which phylogenetically based comparative methods can contribute to biogeographic research. PMID:21768153

  3. Ligula intestinalis--a tapeworm contraceptive.

    PubMed

    Arme, Chris

    2002-12-01

    Human contraceptives are 'big business', but might the real breakthrough come out from the pharmaceutical industry but from a tapeworm? Ligula intestinalis can induce infertility in infected fish of the carp family - both males and females. If the mechanism for this can be discovered, this humble flatworm could drastically change contraceptive practices with one pill for all.

  4. A loop-mediated isothermal amplification method for a differential identification of Taenia tapeworms from human: application to a field survey.

    PubMed

    Nkouawa, Agathe; Sako, Yasuhito; Li, Tiaoying; Chen, Xingwang; Nakao, Minoru; Yanagida, Tetsuya; Okamoto, Munehiro; Giraudoux, Patrick; Raoul, Francis; Nakaya, Kazuhiro; Xiao, Ning; Qiu, Jiamin; Qiu, Dongchuan; Craig, Philip S; Ito, Akira

    2012-12-01

    In this study, we applied a loop-mediated isothermal amplification method for identification of human Taenia tapeworms in Tibetan communities in Sichuan, China. Out of 51 proglottids recovered from 35 carriers, 9, 1, and 41 samples were identified as Taenia solium, Taenia asiatica and Taenia saginata, respectively. Same results were obtained afterwards in the laboratory, except one sample. These results demonstrated that the LAMP method enabled rapid identification of parasites in the field surveys, which suggested that this method would contribute to the control of Taenia infections in endemic areas. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  5. Senna leaf extracts induced Ca(+2) homeostasis in a zoonotic tapeworm Hymenolepis diminuta.

    PubMed

    Roy, Saptarshi; Kundu, Suman; Lyndem, Larisha M

    2016-10-01

    Context Plants and plant products have been used in traditional medicine as anthelmintic agents in human and veterinary medicine. Three species of Senna plant, S. alata (L), S. alexandrina (M) and S. occidentalis (L.) Link (Fabaceae) have been shown to have a vermicidal/vermifugal effect on a zoonotic tapeworm Hymenolepis diminuta (Rudolphi) (Cyclophyllidean). Objective The present study validates the mode of action of these Senna plants on the parasite. The alcoholic leaf extract was determined to obtain information on the intracellular free calcium concentration level. Materials and methods Hymenolepis diminuta was maintained in Sprague-Dawley rat model for 2 months. Live parasites collected from infected rat intestine were exposed to 40 mg/mL concentration of each plant extracts prepared in phosphate buffer saline at 37 °C, till parasite gets paralyzed. The rate of efflux of calcium from the parasite tissue to the medium and the level of intracellular Ca(2+ )concentration were determined by an atomic absorption spectroscopy. Results This study revealed that exposure of the worms to the plant extract leads to disruption in intracellular calcium homeostasis. A significant increase (44.6% and 25%) of efflux in Ca(2+ )from the tissue to the incubated medium was observed. Senna alata showed high rate of efflux (5.32 mg/g) followed by S. alexandria and S. occidentalis (both 4.6 mg/g) compared with control (3.68 mg/g). Discussion and conclusion These results suggest that leaf extracts caused membrane permeability to Ca(2+ )after vacuolization of the tegument under stress and the extracts may contain compound that can be used as a chemotherapeutic agent.

  6. Nine Human Sparganosis Cases in Thailand with Molecular Identification of Causative Parasite Species

    PubMed Central

    Boonyasiri, Adhiratha; Cheunsuchon, Pornsuk; Suputtamongkol, Yupin; Yamasaki, Hiroshi; Sanpool, Oranuch; Maleewong, Wanchai; Intapan, Pewpan M.

    2014-01-01

    Human sparganosis is one of the neglected diseases but important food-borne parasitic zoonoses. The disease is caused by larvae (spargana) of diphyllobothriidean tapeworm. Here, we describe nine cases of human sparganosis, caused by Spirometra erinaceieuropaei in a hospital in Thailand during 2001–2012. Clinical characteristics, treatment, and outcome of cases were revealed. Diagnosis and identification of causative parasite species was made by histopathological investigations followed by a polymerase chain reaction-based molecular method using formalin-fixed paraffin embedded tissues. The DNA samples were extracted from tissues and a partial fragment of cytochrome c oxidase subunit 1 (cox1) gene was amplified for the detection of parasitic DNA. Infection could be prevented by increasing activities on health communication by responsible public health agencies. PMID:24842879

  7. Establishment Success of the Beetle Tapeworm Hymenolepis diminuta Depends on Dose and Host Body Condition

    PubMed Central

    Jane Cassidy, Elizabeth; Vitt Meyling, Nicolai

    2018-01-01

    Parasite effects on host fitness and immunology are often intensity-dependent. Unfortunately, only few experimental studies on insect-parasite interactions attempt to control the level of infection, which may contribute substantial variation to the fitness or immunological parameters of interest. The tapeworm Hymenolepis diminuta—flour beetle Tenebrio molitor model—has been used extensively for ecological and evolutionary host–parasite studies. Successful establishment of H. diminuta cysticercoids in T. molitor relies on ingestion of viable eggs and penetration of the gut wall by the onchosphere. Like in other insect models, there is a lack of standardization of the infection load of cysticercoids in beetles. The aims of this study were to: (1) quantify the relationship between exposure dose and establishment success across several H. diminuta egg concentrations; and (2) test parasite establishment in beetles while experimentally manipulating host body condition and potential immune response to infection. Different egg concentrations of H. diminuta isolated from infected rat feces were fed to individual beetles 7–10 days after eclosion and beetles were exposed to starvation, wounding, or insertion of a nylon filament one hour prior to infection. We found that the establishment of cysticercoids in relation to exposure dose could be accurately predicted using a power function where establishment success was low at three lowest doses and higher at the two highest doses tested. Long-term starvation had a negative effect on cysticercoid establishment success, while insertion of a nylon filament and wounding the beetles did not have any effect compared to control treatment. Thus, our results show that parasite load may be predicted from the exposure dose within the observed range, and that the relationship between dose and parasite establishment success is able to withstand some changes in host body condition. PMID:29401652

  8. Establishment Success of the Beetle Tapeworm Hymenolepis diminuta Depends on Dose and Host Body Condition.

    PubMed

    Dhakal, Suraj; Micki Buss, Sebastian; Jane Cassidy, Elizabeth; Vitt Meyling, Nicolai; Lund Fredensborg, Brian

    2018-02-03

    Parasite effects on host fitness and immunology are often intensity-dependent. Unfortunately, only few experimental studies on insect-parasite interactions attempt to control the level of infection, which may contribute substantial variation to the fitness or immunological parameters of interest. The tapeworm Hymenolepis diminuta -flour beetle Tenebrio molitor model-has been used extensively for ecological and evolutionary host-parasite studies. Successful establishment of H. diminuta cysticercoids in T. molitor relies on ingestion of viable eggs and penetration of the gut wall by the onchosphere. Like in other insect models, there is a lack of standardization of the infection load of cysticercoids in beetles. The aims of this study were to: (1) quantify the relationship between exposure dose and establishment success across several H. diminuta egg concentrations; and (2) test parasite establishment in beetles while experimentally manipulating host body condition and potential immune response to infection. Different egg concentrations of H. diminuta isolated from infected rat feces were fed to individual beetles 7-10 days after eclosion and beetles were exposed to starvation, wounding, or insertion of a nylon filament one hour prior to infection. We found that the establishment of cysticercoids in relation to exposure dose could be accurately predicted using a power function where establishment success was low at three lowest doses and higher at the two highest doses tested. Long-term starvation had a negative effect on cysticercoid establishment success, while insertion of a nylon filament and wounding the beetles did not have any effect compared to control treatment. Thus, our results show that parasite load may be predicted from the exposure dose within the observed range, and that the relationship between dose and parasite establishment success is able to withstand some changes in host body condition.

  9. Policy, phylogeny, and the parasite.

    PubMed

    Stentiford, Grant D; Feist, Stephen W; Stone, David M; Peeler, Edmund J; Bass, David

    2014-06-01

    Animal diseases gain political attention by their inclusion on lists of global bodies such as those of the World Organisation for Animal Health (OIE). Inclusion requires national governments to report outbreaks promptly but may lead to trading restrictions between nations in an attempt to limit spread. Detection therefore has consequences that may have direct impact from farm to state levels. We consider here current approaches to discriminating listed parasites from related but unlisted counterparts. We outline necessary drivers for the discrimination of important taxa and how these may be influenced by national policies. Further, we propose a set of 'best practice' measures, broadly based upon current taxonomic philosophies for protists and metazoans, that should be applied when defining taxa for listing as notifiable. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  10. Helminth parasites of native Hawaiian freshwater fishes: an example of extreme ecological isolation.

    PubMed

    Font, W F; Tate, D C

    1994-10-01

    The Hawaiian Islands harbor a depauperate native freshwater fish fauna comprised of 4 endemic gobies (Gobiidae) and 1 endemic sleeper (Eleotridae). We hypothesized that the natural helminth parasite community of these stream fishes would be depauperate because of colonizing constraints. In the absence of exotic fishes, native fishes in streams of Hanakapi'ai and Nu'alolo valleys harbored no adult helminth parasites. In Hakalau Stream on Hawai'i and Wainiha River on Kaua'i, we found introduced swordtails and guppies (Poeciliidae); here, the native gobioid fishes shared species of helminths with poeciliids. They were the nematode Camallanus cotti, the Asian tapeworm Bothriocephalus acheilognathi, and the leech Myzobdella lugubris. Such parasitological data should be incorporated into management plans for the conservation of native Hawaiian stream fishes as these parasites have been previously demonstrated to cause disease.

  11. Intestinal parasites in First World War German soldiers from "Kilianstollen", Carspach, France.

    PubMed

    Le Bailly, Matthieu; Landolt, Michaël; Mauchamp, Leslie; Dufour, Benjamin

    2014-01-01

    Paleoparasitological investigations revealed the presence of intestinal helminths in samples taken from the abdominal cavities of two German soldiers, recovered in the First World War site named "Kilianstollen" in Carspach, France. Eggs from roundworm, whipworm, tapeworm and capillariids were identified. The morphological and morphometrical comparison, followed by statistical analyses, showed that the Carspach capillariid eggs are similar to rodent parasites. Poor sanitary conditions in the trenches, the lack of knowledge of parasites, and the widespread presence of commensal animals, can explain the occurrence of such parasites in human intestines. This study is the second dealing with 20th century human samples. It confirms the presence of intestinal worms in First World War German soldiers. In this case study, the application of statistics to precise measurements facilitated the diagnosis of ancient helminth eggs and completed the microscopic approach.

  12. 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.

  13. Experimental infection of the endangered bonytail chub (Gila elegans) with the Asian fish tapeworm (Bothriocephalus acheilognathi): impacts on survival, growth, and condition

    USGS Publications Warehouse

    Hansen, S.P.; Choudhury, A.; Heisey, D.M.; Ahumada, J.A.; Hoffnagle, T.L.; Cole, Rebecca A.

    2006-01-01

    Bothriocephalus acheilognathi Yamaguti, 1934, a tapeworm known to be pathogenic to some fish species, has become established in the endangered humpback chub (Gila cypha Miller, 1964) in Grand Canyon, USA, following the tapeworm’s introduction into the Colorado River system. The potential impact of this tapeworm on humpback chub was studied by exposing the closely related bonytail chub (Gila elegans Baird and Girard, 1853) to the parasite under a range of conditions that included potential stressors of humpback chub in their natal waters, such as abrupt temperature change and a limited food base. Survival of infected fish under low food rations was considerably lower than that of control fish, and mortality of infected fish began 20 days earlier. Growth of infected fish was significantly reduced, and negative changes in health condition indices were found. No significant negative impacts were revealed from the synergistic effects between temperature shock and infection. Bothriocephalus acheilognathi does present a potential threat to humpback chub in Grand Canyon and should be considered, along with conventional concerns involving altered flow regimes and predation, when management decisions are made concerning conservation of this endangered species.

  14. Human intestinal parasites from a Mamluk Period cesspool in the Christian quarter of Jerusalem: Potential indicators of long distance travel in the 15th century AD.

    PubMed

    Yeh, Hui-Yuan; Prag, Kay; Clamer, Christa; Humbert, Jean-Baptiste; Mitchell, Piers D

    2015-06-01

    The aim of this research is to determine which parasites were present in a mediaeval latrine from the old city of Jerusalem. This latrine contains fragments of pottery from the Middle East and also from Italy, suggesting links of some kind with Europe. Excavation identified two separate entry chutes emptying in a shared cesspool. Radiocarbon dating and pottery analysis is compatible with a date of use in the late fifteenth century and early sixteenth century. Twelve coprolites (preserved stool) and mixed cesspool sediment were analysed with light microscopy and enzyme-linked immunosorbent assay (ELISA). Six species of intestinal parasites were identified. These were the helminths Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm), Taenia sp. (beef/pork/asiatic tapeworm) Diphyllobothrium sp. (fish tapeworm), and two protozoa that can cause dysentery (Entamoeba histolytica and Giardia duodenalis). While roundworm and whipworm were found in every sample, the other parasite species were present in only one or two samples each, suggesting that only a minority of those using the latrine were infected with those species. The role of Jerusalem as a site for long distance trade, migration or pilgrimage is considered when interpreting the Italian pottery and the parasites present, especially E. histolytica and Diphyllobothrium sp. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Diverse sampling of East African haemosporidians reveals chiropteran origin of malaria parasites in primates and rodents.

    PubMed

    Lutz, Holly L; Patterson, Bruce D; Kerbis Peterhans, Julian C; Stanley, William T; Webala, Paul W; Gnoske, Thomas P; Hackett, Shannon J; Stanhope, Michael J

    2016-06-01

    Phylogenies of parasites provide hypotheses on the history of their movements between hosts, leading to important insights regarding the processes of host switching that underlie modern-day epidemics. Haemosporidian (malaria) parasites lack a well resolved phylogeny, which has impeded the study of evolutionary processes associated with host-switching in this group. Here we present a novel phylogenetic hypothesis that suggests bats served as the ancestral hosts of malaria parasites in primates and rodents. Expanding upon current taxon sampling of Afrotropical bat and bird parasites, we find strong support for all major nodes in the haemosporidian tree using both Bayesian and maximum likelihood approaches. Our analyses support a single transition of haemosporidian parasites from saurian to chiropteran hosts, and do not support a monophyletic relationship between Plasmodium parasites of birds and mammals. We find, for the first time, that Hepatocystis and Plasmodium parasites of mammals represent reciprocally monophyletic evolutionary lineages. These results highlight the importance of broad taxonomic sampling when analyzing phylogenetic relationships, and have important implications for our understanding of key host switching events in the history of malaria parasite evolution. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Human-induced eutrophication maintains high parasite prevalence in breeding threespine stickleback populations.

    PubMed

    Budria, Alexandre; Candolin, Ulrika

    2015-04-01

    Anthropogenic activities are having profound impacts on species interactions, with further consequences for populations and communities. We investigated the influence that anthropogenic eutrophication has on the prevalence of the parasitic tapeworm Schistocephalus solidus in threespine stickleback Gasterosteus aculeatus populations. We caught stickleback from four areas along the coast of Finland, and within each area from one undisturbed and one eutrophied habitat. We found the prevalence of the parasite to be lower in the eutrophied habitats at the start of the breeding season, probably because of fewer piscivorous birds that transmit the parasite. However, while the prevalence of the parasite declined across the season in the undisturbed habitat, it did less so in eutrophied habitats. We discuss different processes that could be behind the differences, such as lower predation rate on infected fish, higher food availability and less dispersal in eutrophied habitats. We found no effect of eutrophication on the proportion of infected stickleback that entered reproductive condition. Together with earlier findings, this suggests that eutrophication increases the proportion of infected stickleback that reproduce. This could promote the evolution of less parasite resistant populations, with potential consequences for the viability of the interacting parties of the host-parasite system.

  17. Everyday and exotic foodborne parasites

    PubMed Central

    Lee, Marilyn B

    2000-01-01

    Everyday foodborne parasites, which are endemic in Canada, include the protozoans Entamoeba histolytica, Giardia lamblia and Cryptosporidium parvum. However, these parasites are most frequently acquired through unfiltered drinking water, homosexual activity or close personal contact such as in daycare centres and occasionally via a food vehicle. It is likely that many foodborne outbreaks from these protozoa go undetected. Transmission of helminth infections, such as tapeworms, is rare in Canada because of effective sewage treatment. However, a common foodborne parasite of significance is Toxoplasma gondii. Although infection can be acquired from accidental ingestion of oocysts from cat feces, infection can also result from consumption of tissue cysts in undercooked meat, such as pork or lamb. Congenital transmission poses an immense financial burden, costing Canada an estimated $240 million annually. Also of concern is toxoplasmosis in AIDS patients, which may lead to toxoplasmosis encephalitis, the second most common AIDS-related opportunistic infection of the central nervous system. Exotic parasites (ie, those acquired from abroad or from imported food) are of growing concern because more Canadians are travelling and the number of Canada's trading partners is increasing. Since 1996, over 3000 cases of Cyclospora infection reported in the United States and Canada were epidemiologically associated with importation of Guatemalan raspberries. Unlike toxoplasmosis, where strategies for control largely rest with individual practices, control of cyclosporiasis rests with government policy, which should prohibit the importation of foods at high risk. PMID:18159283

  18. Gastrointestinal parasites in an isolated Norwegian population of wild red deer (Cervus elaphus).

    PubMed

    Davidson, Rebecca K; Kutz, Susan J; Madslien, Knut; Hoberg, Eric; Handeland, Kjell

    2014-10-08

    Thirteen red deer (Cervus elaphus), culled from the isolated population at the Mongstad Oil Refinery, Norway, were investigated for gastrointestinal helminths. These animals, enclosed by the refinery fence, do not have contact with other ruminants and have a high population density considering the available browsing area (1 km(2)) within the refinery site (3 km(2)). The population was estimated to be 110-130 at the time of culling. The helminth fauna among these sampled red deer was enumerated and species were identified based on morphology. Ostertagia leptospicularis/O. kolchida was detected in 83% [CI 55 - 95%], Spiculopteragia spiculoptera/S. mathevossiani in 92% [CI 65 - 99%] and Trichostrongylus axei in 42%, [CI 19 - 68%] of the abomasa examined. Characterisation of the intestinal parasite fauna revealed Capillaria bovis, Cooperia oncophora, Oesophagostomum venulosum, Trichuris globulosa and tapeworm fragments (presumed anoplocephalids) in seven individuals. Only one calf had an infection with more than one intestinal helminth (tapeworm fragment and Trichuris globulosa). The remaining six deer had single species intestinal infections. No significant age related trends were seen, with the exception of higher intensity of infection of T. axei in yearlings relative to other age classes. Assessment of abomasal parasite burden and body condition revealed no significant trends. In calves, statistically non-significant correlation was seen between increased parasite burden and decreased slaughter weight, whilst the opposite was seen in adults with the heaviest adults exhibiting the higher burdens. Given the small sample size the trends that were seen need further investigation. The parasite burden was aggregated with three adult red deer harbouring 75% of the total abomasal parasite count. This isolated population was parasitised by a reduced subset of gastrointestinal nematodes typical of this cervid across an extensive geographic range in Eurasia. The intensity

  19. The evolution of parasitism in Nematoda.

    PubMed

    Blaxter, Mark; Koutsovoulos, Georgios

    2015-02-01

    Nematodes are abundant and diverse, and include many parasitic species. Molecular phylogenetic analyses have shown that parasitism of plants and animals has arisen at least 15 times independently. Extant nematode species also display lifestyles that are proposed to be on the evolutionary trajectory to parasitism. Recent advances have permitted the determination of the genomes and transcriptomes of many nematode species. These new data can be used to further resolve the phylogeny of Nematoda, and identify possible genetic patterns associated with parasitism. Plant-parasitic nematode genomes show evidence of horizontal gene transfer from other members of the rhizosphere, and these genes play important roles in the parasite-host interface. Similar horizontal transfer is not evident in animal parasitic groups. Many nematodes have bacterial symbionts that can be essential for survival. Horizontal transfer from symbionts to the nematode is also common, but its biological importance is unclear. Over 100 nematode species are currently targeted for sequencing, and these data will yield important insights into the biology and evolutionary history of parasitism. It is important that these new technologies are also applied to free-living taxa, so that the pre-parasitic ground state can be inferred, and the novelties associated with parasitism isolated.

  20. The tapeworm Ligula intestinalis (Cestoda: Pseudophyllidea) inhibits LH expression and puberty in its teleost host, Rutilus rutilus.

    PubMed

    Carter, V; Pierce, R; Dufour, S; Arme, C; Hoole, D

    2005-12-01

    The tapeworm Ligula intestinalis occurs in the body cavity of its cyprinid second intermediate host, in this study the roach Rutilus rutilus, and inhibits host gonadal development. The mechanism by which infected fish are prevented from reproducing is unknown. Comparison of parameters, such as body length and weight, and condition factor and age, between infected and uninfected individuals, indicated only minor effects of parasitism on growth and condition. In contrast, seasonal gonadal development, as observed in uninfected fish, did not occur in infected fish, and gonads remained small and blocked at the primary oocyte stage in female roach. As immature ovaries and testes are still present, the parasite is presumed to act upon the brain-pituitary-gonadal axis of the fish to inhibit further development of reproductive organs. We investigated the Ligula/fish interaction at the level of the pituitary gland by determination of gonadotrophin (LH) content using a heterologous RIA for carp (Cyprinus carpio) LHbeta subunit. The results indicated that the pituitary glands of infected roach contained approximately 50% less LH than non-infected fish. After the cloning and sequencing of roach LHbeta subunit, we measured roach LHbeta mRNA levels by real-time RT-PCR. A corresponding 50% reduction in LHbeta mRNA pituitary levels was determined. These results reflect a significant and measurable effect of parasitism on the pituitary gland, and lend support to the hypothesis that excretory/secretory products released from the parasite interact with the brain-pituitary-gonadal axis of the fish host and thus inhibit gonadal development.

  1. A view of early vertebrate evolution inferred from the phylogeny of polystome parasites (Monogenea: Polystomatidae).

    PubMed Central

    Verneau, Olivier; Bentz, Sophie; Sinnappah, Neeta Devi; du Preez, Louis; Whittington, Ian; Combes, Claude

    2002-01-01

    The Polystomatidae is the only family within the Monogenea to parasitize sarcopterygians such as the Australian lungfish Neoceratodus poisteri and freshwater tetrapods (lissamphibians and chelonians). We present a phylogeny based on partial 18S rDNA sequences of 26 species of Polystomatidae and three taxon from the infrasubclass Oligonchoinea (= Polyopisthocotylea) obtained from the gills of teleost fishes. The basal position of the polystome from lungfish within the Polystomatidae suggests that the family arose during the evolutionary transition between actinopterygians and sarcopterygians, ca. 425 million years (Myr) ago. The monophyly of the polystomatid lineages from chelonian and lissamphibian hosts, in addition to estimates of the divergence times, indicate that polystomatids from turtles radiated ca. 191 Myr ago, following a switch from an aquatic amniote presumed to be extinct to turtles, which diversified in the Upper Triassic. Within polystomatids from lissamphibians, we observe a polytomy of four lineages, namely caudatan, neobatrachian, pelobatid and pipid polystomatid lineages, which occurred ca. 246 Myr ago according to molecular divergence-time estimates. This suggests that the first polystomatids of amphibians originated during the evolution and diversification of lissamphibian orders and suborders ca. 250 Myr ago. Finally, we report a vicariance event between two major groups of neobatrachian polystomes, which is probably linked to the separation of South America from Africa ca. 100 Myr ago. PMID:11886648

  2. Expression of gonadotropin subunits in roach (Rutilus rutilus, Cyprinidae) infected with plerocercoids of the tapeworm Ligula intestinalis (Cestoda).

    PubMed

    Trubiroha, Achim; Wuertz, Sven; Frank, Sabrina N; Sures, Bernd; Kloas, Werner

    2009-11-01

    Plerocercoids of the tapeworm Ligula intestinalis (Cestoda: Bothriocephalidea) have been reported to inhibit gametogenesis of their intermediate fish hosts. However, mechanistic studies are rare and the proximate cues leading to impaired reproduction still remain unknown. In the present study we investigated the effects of infection by L. intestinalis on reproductive parameters of roach (Rutilus rutilus, Cyprinidae), a common fish host of this parasite. Field studies on roach demonstrated that in both genders infection prevented gonad development. As revealed by quantitative PCR, infection was accompanied by essentially lower pituitary expression of follicle-stimulating hormone beta-subunit (FSHbeta) and luteinizing hormone beta-subunit (LHbeta) mRNA compared with uninfected roach, providing clear evidence for gonadotropin-insufficiency as the cause of arrested gametogenesis. Under controlled laboratory conditions infected roach showed lower mRNA levels of FSHbeta but not of LHbeta, despite histology revealing similar gonad stages as in uninfected conspecifics. These findings indicate the involvement of FSH rather than LH in mediating effects of infection early during gonad development in roach. Moreover, the impact of L. intestinalis on reproductive parameters of roach appeared to be independent of the parasite burden. Together, these data provide valuable information on the role of FSH and LH as mediators of parasite-induced sterilization in a vertebrate and implicate the selective inhibition of host reproduction by L. intestinalis as a natural source of endocrine disruption in fish.

  3. Numerical and functional responses of intestinal helminths in three rajid skates: evidence for competition between parasites?

    PubMed

    Randhawa, Haseeb S

    2012-11-01

    Host-parasite interactions generally involve communities of parasites. Within these communities, species will co-exist and/or interact with one another in a manner either benefiting the species involved or to the detriment of one or more of the species. At the level of helminth infracommunities, evidence for intra- and inter-specific competition includes numerical responses, i.e. those regulating helminth intensity of infection, and functional responses, i.e. where the presence of competitors modifies the realised niche of infrapopulations. The objectives of this study are to assess the numerical and functional responses of helminths in infracommunities from 3 rajid skates using general linear models. Despite a lack of numerical responses, functional responses to intra- and inter-specific interactions were observed. A positive correlation between the number of individuals in an infrapopulation and its niche breadth (functional response) was observed for the tapeworms Pseudanthobothrium spp. and Echeneibothrium spp., in all their respective hosts, and for the nematode Pseudanisakis sp. in the little skate. Evidence for inter-specific competition includes niche shifts in Pseudanthobothrium purtoni (ex little skate) and Pseudanisakis sp. (ex thorny skate) in the presence of Pseudanisakis sp. and the tapeworm Grillotia sp., respectively. These results are consistent with other studies in providing evidence for competition between helminths of skates.

  4. [The structure of low-abundance and crowded infrapopulations of the tapeworm Hymenolepis diminuta inbred line--WMS IL1].

    PubMed

    Stradowski, M

    2001-01-01

    An average of 4.9 tapeworms were discovered on day 7 of a low-abundance H. diminuta infection of rats of race WAG alb. After 11 months, the mean was only relatively slightly lower at 3.6. These means represent 97.1 and 71.4% of the 5 cysticercoids supplied. In turn, 7 days and 11 months after rats were supplied with 110 cysticercoids, the respective percent-ages were 85.1 and 56.0. All 7- and 12-day tapeworms from the low-abundance and crowded infrapopulations were characterized by the presence of a terminal proglottid of lingulate shape, in which the excretory canals joined. In contrast, older (48-day and 11-month-old) worms showed typical apolysis of gravid proglottids. There were no reports of the destrobilation of tapeworms, and the relatively large number of tapeworms persisting 11 months into the infection is particularly noteworthy. The results point to the lack of any rapid rejection of tapeworms of the kind characterized in many other studies on H. diminuta.

  5. The complete mitochondrial genome of the dwarf tapeworm Hymenolepis nana--a neglected zoonotic helminth.

    PubMed

    Cheng, Tian; Liu, Guo-Hua; Song, Hui-Qun; Lin, Rui-Qing; Zhu, Xing-Quan

    2016-03-01

    Hymenolepis nana, commonly known as the dwarf tapeworm, is one of the most common tapeworms of humans and rodents and can cause hymenolepiasis. Although this zoonotic tapeworm is of socio-economic significance in many countries of the world, its genetics, systematics, epidemiology, and biology are poorly understood. In the present study, we sequenced and characterized the complete mitochondrial (mt) genome of H. nana. The mt genome is 13,764 bp in size and encodes 36 genes, including 12 protein-coding genes, 2 ribosomal RNA, and 22 transfer RNA genes. All genes are transcribed in the same direction. The gene order and genome content are completely identical with their congener Hymenolepis diminuta. Phylogenetic analyses based on concatenated amino acid sequences of 12 protein-coding genes by Bayesian inference, Maximum likelihood, and Maximum parsimony showed the division of class Cestoda into two orders, supported the monophylies of both the orders Cyclophyllidea and Pseudophyllidea. Analyses of mt genome sequences also support the monophylies of the three families Taeniidae, Hymenolepididae, and Diphyllobothriidae. This novel mt genome provides a useful genetic marker for studying the molecular epidemiology, systematics, and population genetics of the dwarf tapeworm and should have implications for the diagnosis, prevention, and control of hymenolepiasis in humans.

  6. Direct manipulation of insect reproduction by agents of parasite origin

    PubMed Central

    Webb, T. J.; Hurd, H.

    1999-01-01

    Reproductive output of female Tenebrio molitor beetles is reduced upon infection with metacestodes of the rat tapeworm, Hymenolepis diminuta. We are using this as a model to investigate the adaptive significance of parasite-induced curtailment of insect reproduction. Production of the yolk protein vitellogenin (Vg) in the insect fat body is significantly reduced both in vitro and in vivo by metacestodes. Synthesis can be measured by using [14C]L-leucine incorporation, followed by immunoprecipitation. In this paper we demonstrate that a significant decrease in [14C]Vg can be produced by an acetic acid extract of the parasite. Conclusive evidence is presented that the active component(s) originate from the metacestodes: an extract of parasites grown entirely axenically has similar deleterious effects. The developmental stage of the metacestode is important: immature (stage I to II) parasites had greater capacity to suppress Vg synthesis than mature ones (stage V to VI). Examination of the chemical nature of the effector molecule(s) revealed that acetic-acid-extractable, boiling-resistant, pronase-sensitive agents in the molecular mass range 10 to 50 kDa reduced Vg synthesis by 47.4%. These data suggest that metacestodes produce a modulator molecule that directly affects insect vitellogenesis and, therefore, that reduction of host fitness may confer a selective advantage upon the parasite.

  7. Cophylogeny of the anther smut fungi and their caryophyllaceous hosts: Prevalence of host shifts and importance of delimiting parasite species for inferring cospeciation

    PubMed Central

    2008-01-01

    Background Using phylogenetic approaches, the expectation that parallel cladogenesis should occur between parasites and hosts has been validated in some studies, but most others provided evidence for frequent host shifts. Here we examine the evolutionary history of the association between Microbotryum fungi that cause anther smut disease and their Caryophyllaceous hosts. We investigated the congruence between host and parasite phylogenies, inferred cospeciation events and host shifts, and assessed whether geography or plant ecology could have facilitated the putative host shifts identified. For cophylogeny analyses on microorganisms, parasite strains isolated from different host species are generally considered to represent independent evolutionary lineages, often without checking whether some strains actually belong to the same generalist species. Such an approach may mistake intraspecific nodes for speciation events and thus bias the results of cophylogeny analyses if generalist species are found on closely related hosts. A second aim of this study was therefore to evaluate the impact of species delimitation on the inferences of cospeciation. Results We inferred a multiple gene phylogeny of anther smut strains from 21 host plants from several geographic origins, complementing a previous study on the delimitation of fungal species and their host specificities. We also inferred a multi-gene phylogeny of their host plants, and the two phylogenies were compared. A significant level of cospeciation was found when each host species was considered to harbour a specific parasite strain, i.e. when generalist parasite species were not recognized as such. This approach overestimated the frequency of cocladogenesis because individual parasite species capable of infecting multiple host species (i.e. generalists) were found on closely related hosts. When generalist parasite species were appropriately delimited and only a single representative of each species was retained

  8. Growth and ontogeny of the tapeworm Schistocephalus solidus in its copepod first host affects performance in its stickleback second intermediate host

    PubMed Central

    2012-01-01

    Background For parasites with complex life cycles, size at transmission can impact performance in the next host, thereby coupling parasite phenotypes in the two consecutive hosts. However, a handful of studies with parasites, and numerous studies with free-living, complex-life-cycle animals, have found that larval size correlates poorly with fitness under particular conditions, implying that other traits, such as physiological or ontogenetic variation, may predict fitness more reliably. Using the tapeworm Schistocephalus solidus, we evaluated how parasite size, age, and ontogeny in the copepod first host interact to determine performance in the stickleback second host. Methods We raised infected copepods under two feeding treatments (to manipulate parasite growth), and then exposed fish to worms of two different ages (to manipulate parasite ontogeny). We assessed how growth and ontogeny in copepods affected three measures of fitness in fish: infection probability, growth rate, and energy storage. Results Our main, novel finding is that the increase in fitness (infection probability and growth in fish) with larval size and age observed in previous studies on S. solidus seems to be largely mediated by ontogenetic variation. Worms that developed rapidly (had a cercomer after 9 days in copepods) were able to infect fish at an earlier age, and they grew to larger sizes with larger energy reserves in fish. Infection probability in fish increased with larval size chiefly in young worms, when size and ontogeny are positively correlated, but not in older worms that had essentially completed their larval development in copepods. Conclusions Transmission to sticklebacks as a small, not-yet-fully developed larva has clear costs for S. solidus, but it remains unclear what prevents the evolution of faster growth and development in this species. PMID:22564512

  9. Pentastomiasis and other parasitic zoonoses from reptiles and amphibians.

    PubMed

    Pantchev, Nikola; Tappe, Dennis

    2011-01-01

    Reptiles are growing in popularity as pets.The colonization of reptiles and amphibians by parasites and the resulting disease conditions are the most common problems seen in captive animals.This review focuses on pentastomiasis and sparganosis, important parasitic zoonoses of reptiles and amphibians, respectively, and free living-amoebae. Humans are suitable accidental hosts for some pentastomid species (particularly Armillifer and Porocephalus). In geographical areas with special ethnics, such as in West and Central Africa, and East Asia, 8-45% of the human population can be affected. Usually the larvae are coincidentally found during abdominal surgeries. However, fatalities have been described. Extreme caution is necessary when handling infected reptiles. Ocular or cerebral sparganosis is not uncommonly found in humans in East Asia. This disease is caused by spargana, tapeworm larvae (plerocercoids) of Spirometra sp. The infection occurs when uncooked meat from reptiles or amphibians is applied to wounds or eyes and the parasites migrate directly to human tissue, or by consumption of contaminated food or water. As a consequence of the reptile's predatory behaviour, the full spectrum of endo- and ectoparasites from potential prey animals can be found as transiting parasites in the intestinal tract, e. g. Hymenolepis nana, Cryptosporidium (C.) muris, C parvum or Capillaria hepatica. Occasionally, free-living amoebae are also found in reptile faeces (Acanthamoeba, Naegleria, Hartmanella, Vahlkampfia or Echinamoeba sp.).

  10. Establishment of the onset of host specificity in four phyllobothriid tapeworm species (Cestoda: Tetraphyllidea) using a molecular approach.

    PubMed

    Randhawa, H S; Saunders, G W; Burt, M D B

    2007-08-01

    A parasitological survey in the Bay of Fundy, Canada, resulted in the recovery of mature specimens from 5 species of phyllobothriid tapeworms (Cestoda: Tetraphyllidea) from 4 rajid skates: Echeneibothrium canadensis and E. dubium abyssorum specimens from Amblyraja radiata; E. vernetae and Pseudanthobothrium n.sp. from Leucoraja erinacea and L. ocellata; and P. hanseni from A. radiata and Malacoraja senta. Partial sequence data of a variable region (D2) from the large subunit ribosomal DNA (LSU) were used here to determine the host distribution of immature specimens for 4 of these 5 species (E. d. abyssorum was not included in the analyses). Immature specimens from both Pseudanthobothrium spp. were identified in the same hosts as recorded previously for mature specimens, thus suggesting that there are mechanisms that prevent the attachment of the parasite in an 'unsuitable' host species. Immature E. canadensis specimens were recovered exclusively from A. radiata, whereas immature E. vernetae specimens were recovered from L. erinacea and A. radiata, despite the latter host species not harbouring mature E. vernetae specimens. Their presence in the latter host species may be explained by host restriction or resistance, which allows the attachment of the parasites in the 'wrong' host species, but not establishment or development.

  11. Seasonal and biogeographical patterns of gastrointestinal parasites in large carnivores: wolves in a coastal archipelago.

    PubMed

    Bryan, Heather M; Darimont, Chris T; Hill, Janet E; Paquet, Paul C; Thompson, R C Andrew; Wagner, Brent; Smits, Judit E G

    2012-05-01

    Parasites are increasingly recognized for their profound influences on individual, population and ecosystem health. We provide the first report of gastrointestinal parasites in gray wolves from the central and north coasts of British Columbia, Canada. Across 60 000 km(2), wolf feces were collected from 34 packs in 2005-2008. At a smaller spatial scale (3300 km(2)), 8 packs were sampled in spring and autumn. Parasite eggs, larvae, and cysts were identified using standard flotation techniques and morphology. A subset of samples was analysed by PCR and sequencing to identify tapeworm eggs (n=9) and Giardia cysts (n=14). We detected ≥14 parasite taxa in 1558 fecal samples. Sarcocystis sporocysts occurred most frequently in feces (43·7%), followed by taeniid eggs (23·9%), Diphyllobothrium eggs (9·1%), Giardia cysts (6·8%), Toxocara canis eggs (2·1%), and Cryptosporidium oocysts (1·7%). Other parasites occurred in ≤1% of feces. Genetic analyses revealed Echinococcus canadensis strains G8 and G10, Taenia ovis krabbei, Diphyllobothrium nehonkaiense, and Giardia duodenalis assemblages A and B. Parasite prevalence differed between seasons and island/mainland sites. Patterns in parasite prevalence reflect seasonal and spatial resource use by wolves and wolf-salmon associations. These data provide a unique, extensive and solid baseline for monitoring parasite community structure in relation to environmental change.

  12. 9 CFR 311.24 - Hogs affected with tapeworm cysts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Hogs affected with tapeworm cysts. 311.24 Section 311.24 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... INSPECTION AND CERTIFICATION DISPOSAL OF DISEASED OR OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.24 Hogs...

  13. The effect of herbivore faeces on the edaphic mite community: implications for tapeworm transmission.

    PubMed

    Václav, Radovan; Kalúz, Stanislav

    2014-03-01

    Oribatid mites may be of epidemiological and medical importance because several species have been shown to serve as intermediate hosts for anoplocephalid tapeworms of wild and domestic animals. Despite their economic and conservation significance, relatively few studies examined factors influencing the effective number of oribatid mites that can serve as intermediate hosts. We examined variation in the structure of the edaphic arthropod community in functionally different territory parts of the Alpine marmot (Marmota marmota latirostris), a known definitive host of a prevalent anoplocephalid tapeworm, Ctenotaenia marmotae. We used a field experiment to test whether the abundance of oribatid mites in marmot pastures is affected by the presence of fresh herbivore faeces. We found that the abundance of soil and litter dwelling oribatid mites in marmot pastures did not change shortly after faeces addition. In contrast, numbers of other predominant soil-litter and phoretic microarthropods increased after faeces addition. The abundance of the two predominant phoretic mites colonizing the faeces was inversely related to the abundance of oribatid mites. In contrast, the abundance of a ubiquitous soil-litter mesostigmatid mite was a positive function of oribatid numbers. Although absolute numbers of oribatid mites did not change after faeces addition, our study suggests that, depending on soil quality or type, the probability of tapeworm egg ingestion by oribatid mites can be reduced due to increased interspecific prey-predatory and trophic interactions. Latrine site selection in Alpine marmots is consistent with a reduced probability of tapeworm transmission by oribatids.

  14. Mitochondrial DNA suggests at least 11 origins of parasitism in angiosperms and reveals genomic chimerism in parasitic plants

    PubMed Central

    Barkman, Todd J; McNeal, Joel R; Lim, Seok-Hong; Coat, Gwen; Croom, Henrietta B; Young, Nelson D; dePamphilis, Claude W

    2007-01-01

    Background Some of the most difficult phylogenetic questions in evolutionary biology involve identification of the free-living relatives of parasitic organisms, particularly those of parasitic flowering plants. Consequently, the number of origins of parasitism and the phylogenetic distribution of the heterotrophic lifestyle among angiosperm lineages is unclear. Results Here we report the results of a phylogenetic analysis of 102 species of seed plants designed to infer the position of all haustorial parasitic angiosperm lineages using three mitochondrial genes: atp1, coxI, and matR. Overall, the mtDNA phylogeny agrees with independent studies in terms of non-parasitic plant relationships and reveals at least 11 independent origins of parasitism in angiosperms, eight of which consist entirely of holoparasitic species that lack photosynthetic ability. From these results, it can be inferred that modern-day parasites have disproportionately evolved in certain lineages and that the endoparasitic habit has arisen by convergence in four clades. In addition, reduced taxon, single gene analyses revealed multiple horizontal transfers of atp1 from host to parasite lineage, suggesting that parasites may be important vectors of horizontal gene transfer in angiosperms. Furthermore, in Pilostyles we show evidence for a recent host-to-parasite atp1 transfer based on a chimeric gene sequence that indicates multiple historical xenologous gene acquisitions have occurred in this endoparasite. Finally, the phylogenetic relationships inferred for parasites indicate that the origins of parasitism in angiosperms are strongly correlated with horizontal acquisitions of the invasive coxI group I intron. Conclusion Collectively, these results indicate that the parasitic lifestyle has arisen repeatedly in angiosperm evolutionary history and results in increasing parasite genomic chimerism over time. PMID:18154671

  15. 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

    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.

  16. Public health significance of zoonotic tapeworms in Korea.

    PubMed

    Moon, J R

    1976-06-01

    Through an epidemiological review on the zoonotic tapeworms in Korea, the frequency and severity of the zoonoses have been recognized. Taeniasis and human cysticercosis are of importance to the public health in Korea. The frequency of taeniasis is 0.3% to 12.7% discovered by stool examination and 4.5% to 38.0% discovered by questionaire survey. Taeniasis occurs more frequently in males than in females and, especially, in both sexes in the age-group of 20 to 49. T. saginata is more common that T. solium. No case of human cysticercosis caused by T.saginata has been reported in Korea. To the contrary, human cysticercosis caused by T. solium has been reported frequently during the 1960's. The severity of human cysticercosis is a significant problem of public health in Korea. Old data on bovine cysticercosis in the 1920's and 1930's are not useful for present control measures. Systematic surveys on bovine and swine cysticercosis as well as taeniasis and human cysticercosis are needed in Korea. Cases of sparganosis have been reported frequently during the past 15 years. Most of the 34 cases of sparganosis reported involved the eating of raw snakes and frogs. Most of the cases occurred in older males. Sparganosis in snakes, frogs, chickens, and swine has been reported in Korea. Human infection of Hymenolepis nana ranged from 0.2% to 1.4% discovered by stool examination. A few cases of adult worm collections of Diphyllobothrium latum and Hymenolepis diminuta have been reported in Korea. Two cases of human hydatid disease have been reported in Korea. No study on the disease in domestic animals is available. No case of human infection with dog tapeworm has been reported, even though it is highly prevalent in the indigenous dogs in Korea. I recommend that further study on the zoonotic tapeworms be conducted epidemiologically in Korea to get basic data for the public health programming.

  17. 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.

  18. Redescription and resurrection of Bertiella satyri (Cestoda, Anoplocephalidae) parasitizing the orangutan (Pongo abelii) in Indonesia.

    PubMed

    Foitová, Ivona; Mašová, Sárka; Tenora, František; Koubková, Božena; Hodová, Iveta; Vyskočilová, Martina; Baruš, Vlastimil; Nurcahyo, Wisnu

    2011-09-01

    The tapeworm species Bertiella satyri from a semi-wild Sumatran orangutan (Pongo abelii: Ponginae) is redescribed and the sequence of its 18S rDNA is presented. The tapeworms parasitizing the genera Pan, Pongo, Homo and Hylobates from Muséum National d'Histoire Naturelle, Paris and from Muséum d´Histoire Naturelle, Genève are also presented. The validity of B. satyri is confirmed. B. satyri (BSA) differs from the most similar species Bertiella studeri (BSTU) in the following characteristics: (1) testes number, BSTU 300-400; BSA 116-124, (2) genital opening, BSTU regularly alternate; BSA irregularly alternate, (3) Cirrus-sac, BSTU short, 0.250-0.320, does not reach excretory ducts; BSA long, 0.630 × 0.495, reaches excretory ducts, (4) egg size, BSTU 0.053-0.060; BSA 0.030-0.051, (5) host BSTU Pan troglodytes, Africa; BSA Pongo pygmaeus, P. abelii, Indonesia (Borneo, Sumatra). Both species differ according to our material and the name B. satyri (Blanchard, 1891) is resurrected.

  19. [Epidemic status of human key parasitic diseases in Tongcheng City, Anhui Province].

    PubMed

    Long-Zhi, Jiang

    2017-10-24

    To understand the current status of key parasitic diseases in Tongcheng City, so as to provide an epidemiological reference for formulating the scientific planning for "13 th Five-year" parasitic diseases prevention and control. The villages of different levels in Tongcheng City were sampled to investigate the infection of parasitic diseases of residents aged three or more years. Soil-transmitted nemathelminth, intestinal protozoa and Enterobius vermicularis were investigated by the Kato-Katz technique (a fecal sample seized two), iodine smear method and cellophane tape method, respectively. Meanwhile a questionnaire survey was conducted on the basic situation, knowledge and health behaviors of the residents to soiltransmitted nemathelminth infection. Totally 1 023 residents were investigated, and 38 were positive of parasitic infection, with the total infection rate of 3.71%. The soil-transmitted nematodes infection rate was 3.62%, 36 people were infected with hookworm (3.52%), one person was infected with Trichuris trichiura (0.10%), one person was infected with intestinal protozoa ( Blastocystis hominis ). Ascaris lumbricoides , E. vermicularis and tapeworm infections were not founded. The total awareness rate of prevention knowledge, behavior and attitude was 76.93%. The infection rate of soil-transmitted nemathelminth infections is reduced below 5% in Tongcheng City. The main species of parasites is Necator americanus , and the population of the infection is mainly concentrated in the residents over the age of 60 years.

  20. Mitochondrial genomes of parasitic flatworms.

    PubMed

    Le, Thanh H; Blair, David; McManus, Donald P

    2002-05-01

    Complete or near-complete mitochondrial genomes are now available for 11 species or strains of parasitic flatworms belonging to the Trematoda and the Cestoda. The organization of these genomes is not strikingly different from those of other eumetazoans, although one gene (atp8) commonly found in other phyla is absent from flatworms. The gene order in most flatworms has similarities to those seen in higher protostomes such as annelids. However, the gene order has been drastically altered in Schistosoma mansoni, which obscures this possible relationship. Among the sequenced taxa, base composition varies considerably, creating potential difficulties for phylogeny reconstruction. Long non-coding regions are present in all taxa, but these vary in length from only a few hundred to approximately 10000 nucleotides. Among Schistosoma spp., the long non-coding regions are rich in repeats and length variation among individuals is known. Data from mitochondrial genomes are valuable for studies on species identification, phylogenies and biogeography.

  1. Effects of environmental variation on host-parasite interaction in three-spined sticklebacks (Gasterosteus aculeatus).

    PubMed

    Scharsack, Jörn P; Franke, Frederik; Erin, Noémi I; Kuske, Andra; Büscher, Janine; Stolz, Hendrik; Samonte, Irene E; Kurtz, Joachim; Kalbe, Martin

    2016-08-01

    Recent research provides accumulating evidence that the evolutionary dynamics of host-parasite adaptations strongly depend on environmental variation. In this context, the three-spined stickleback (Gasterosteus aculeatus) has become an important research model since it is distributed all over the northern hemisphere and lives in very different habitat types, ranging from marine to freshwater, were it is exposed to a huge diversity of parasites. While a majority of studies start from explorations of sticklebacks in the wild, only relatively few investigations have continued under laboratory conditions. Accordingly, it has often been described that sticklebacks differ in parasite burden between habitats, but the underlying co-evolutionary trajectories are often not well understood. With the present review, we give an overview of the most striking examples of stickleback-parasite-environment interactions discovered in the wild and discuss two model parasites which have received some attention in laboratory studies: the eye fluke Diplostomum pseudospathacaeum, for which host fish show habitat-specific levels of resistance, and the tapeworm Schistocephalus solidus, which manipulates immunity and behavior of its stickleback host to its advantage. Finally, we will concentrate on an important environmental variable, namely temperature, which has prominent effects on the activity of the immune system of ectothermic hosts and on parasite growth rates. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

  2. New multiplex PCR method for the simultaneous diagnosis of the three known species of equine tapeworm.

    PubMed

    Bohórquez, G Alejandro; Luzón, Mónica; Martín-Hernández, Raquel; Meana, Aránzazu

    2015-01-15

    Although several techniques exist for the detection of equine tapeworms in serum and feces, the differential diagnosis of tapeworm infection is usually based on postmortem findings and the morphological identification of eggs in feces. In this study, a multiplex polymerase chain reaction (PCR)-based method for the simultaneuos detection of Anoplocephala magna, Anoplocephala perfoliata and Anoplocephaloides mamillana has been developed and validated. The method simultaneously amplifies hypervariable SSUrRNA gene regions in the three tapeworm species in a single reaction using three pairs of primers, which exclusively amplify the internal transcribed spacer 2 (ITS-2) in each target gene. The method was tested on three types of sample: (a) 1/10, 1/100, 1/500, 1/1000, 1/2000 and 1/5000 dilutions of 70 ng of genomic DNA of the three tapeworm species, (b) DNA extracted from negative aliquots of sediments of negative control fecal samples spiked with 500, 200, 100, 50 and 10 eggs (only for A. magna and A. perfoliata; no A. mamillana eggs available) and (c) DNA extracted from 80, 50, 40, 30, 10 and 1 egg per 2 μl of PCR reaction mix (only for A. magna and A. perfoliata; no A. mamillana eggs available). No amplification was observed against the DNA of Gasterophilus intestinalis, Parascaris equorum and Strongylus vulgaris. The multiplex PCR method emerged as specific for the three tapeworms and was able to identify as few as 50 eggs per fecal sample and as little as 0.7 ng of control genomic DNA obtained from the three species. The method proposed is able to differentiate infections caused by the two most frequent species A. magna or A. perfoliata when the eggs are present in feces and is also able to detect mixed infections by the three cestode species. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. 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

    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

  4. Constructing Phylogenies.

    ERIC Educational Resources Information Center

    Bilardello, Nicholas; Valdes, Linda

    1998-01-01

    Introduces a method for constructing phylogenies using molecular traits and elementary graph theory. Discusses analyzing molecular data and using weighted graphs, minimum-weight spanning trees, and rooted cube phylogenies to display the data. (DDR)

  5. Three new genera and species of tapeworms from the longnose sawshark, Pristiophorus cirratus, with comments on their modes of attachment to the spiral intestine.

    PubMed

    McKenzie, V J; Caira, J N

    1998-04-01

    The spiral intestines of 18 specimens of the longnose sawshark Pristiophorus cirratus, collected from southeastern Australia, were examined for parasites. Three new genera and species of tetraphyllidean tapeworms belonging to the Phyllobothriinae within the Phyllobothriidae were discovered as a result of these necropsies. Flexibothrium ruhnkei n. g., n. sp. differs from all other phyllobothriine tapeworms in its possession of bothridia that each bear an apical sucker and a posterior margin that is flexed anteriorly and fused along the median line of the distal bothridial surface, forming 2 essentially open-faced grooves. Light and scanning electron microscopy of worms attached to the mucosal surface suggest that this species uses the open-faced bothridial grooves, the outermost surface of the anteriorly flexed portion of each bothridium, and the interbothridial surfaces to grasp up to a total of 16 mucosal villi and/or ridges. Cardiobothrium beveridgei n. g., n. sp. is unique among the phyllobothriids in its possession of bothridia each with an apical sucker, marginal loculi, and 4 facial loculi arranged in 2 tandem pairs. This taxon is provisionally placed within the Phyllobothriinae, and the subfamilial diagnosis is emended to include species with facial loculi. Examination of specimens fixed in situ and then removed from the mucosal surface suggests that this species uses the larger, posterior pair of facial loculi of each bothridium to grasp the tips of a pair of adjacent villi in order to attach to the mucosal surface. Bibursibothrium gouldeni n. g., n. sp. also appears to belong in the Phyllobothriinae. Within this subfamily it most closely resembles species of Marsupiobothrium in its possession of pouchlike bothridia. However, it conspicuously differs from species in this genus in that its bothridial pouches are subdivided internally into 2 distinct compartments. Cross sections of individuals of this taxon attached to the mucosal surface indicate that each

  6. Diversity and patterns of interaction of an anuran-parasite network in a neotropical wetland.

    PubMed

    Campião, K M; Ribas, A; Tavares, L E R

    2015-12-01

    We describe the diversity and structure of a host-parasite network of 11 anuran species and their helminth parasites in the Pantanal wetland, Brazil. Specifically, we investigate how the heterogeneous use of space by hosts changes parasite community diversity, and how the local pool of parasites exploits sympatric host species of different habits. We examined 229 anuran specimens, interacting with 32 helminth parasite taxa. Mixed effect models indicated the influence of anuran body size, but not habit, as a determinant of parasite species richness. Variation in parasite taxonomic diversity, however, was not significantly correlated with host size or habit. Parasite community composition was not correlated with host phylogeny, indicating no strong effect of the evolutionary relationships among anurans on the similarities in their parasite communities. Host-parasite network showed a nested and non-modular pattern of interaction, which is probably a result of the low host specificity observed for most helminths in this study. Overall, we found host body size was important in determining parasite community richness, whereas low parasite specificity was important to network structure.

  7. Sex differences in frass production and weight change in Tenebrio molitor (Coleoptera) infected with cysticercoids of the tapeworm Hymenolepis diminuta (Cestoda)

    PubMed Central

    Shea, John F.

    2005-01-01

    In their intermediate host, parasites alter aspects of host physiology including waste production and body weight. Further, this alteration may differ between female and male hosts. To study this, a beetle (Tenebrio molitor)-tapeworm (Hymenolepis diminuta) system was used. Infected and uninfected male and female beetles were individually housed in vials without food. Each beetle's weight change and frass production were measured over 24 h periods at 3, 7, 12 and 16 days post-infection. Treatment (infection) had no effect on weight change, but males lost more weight than females. Further, infected females produced more frass than control females. Males on the day of infection had a higher food intake than females. These results suggest that males will be more exposed to infection than females and could explain why males had a higher median cysticercoid infection level. PMID:17119613

  8. Sex differences in frass production and weight change in Tenebrio molitor (Coleoptera) infected with cysticercoids of the tapeworm Hymenolepis diminuta (Cestoda).

    PubMed

    Shea, John F

    2005-11-11

    In their intermediate host, parasites alter aspects of host physiology including waste production and body weight. Further, this alteration may differ between female and male hosts. To study this, a beetle (Tenebrio molitor)-tapeworm (Hymenolepis diminuta) system was used. Infected and uninfected male and female beetles were individually housed in vials without food. Each beetle's weight change and frass production were measured over 24 h periods at 3, 7, 12 and 16 days post-infection. Treatment (infection) had no effect on weight change, but males lost more weight than females. Further, infected females produced more frass than control females. Males on the day of infection had a higher food intake than females. These results suggest that males will be more exposed to infection than females and could explain why males had a higher median cysticercoid infection level.

  9. Diphyllobothriasis: fish tapeworm disease in the circumpolar north.

    PubMed

    Curtis, M A; Bylund, G

    1991-01-01

    Although fish tapeworm infections in arctic and subarctic residents are often attributed to the cestode Diphyllobothrium latum, other Diphyllobothrium species are frequently responsible. D. dendriticum, for example, occurs throughout the circumpolar area at high latitudes beyond the range of D. latum. Several additional species are also implicated in human infections in northern communities bordering the Pacific: D. ursi from northern Canada and Alaska, D. dalliae from Alaska and Siberia, and D. klebanovskii from Siberia. Routine diagnosis of diphyllobothriasis by coprology does not allow designation of the Diphyllobothrium species involved as their eggs cannot be differentiated and identification of the proglottids from adult worms requires a taxonomic specialist. On the other hand, relevant information on the Diphyllobothrium species most likely to infect the inhabitants of a particular region can be derived from a knowledge of the fish consumed. Larvae of D. dendriticum occur predominantly in salmonid fishes (e.g. arctic char, salmon, trout, whitefish), and this parasite has never been found in pike and perch, the usual intermediate hosts of D. latum. Conversely, D. latum is rarely found in salmonids. D. ursi and D. klebanovskii predominantly occur in Pacific salmon, and D. dalliae in Alaskan blackfish. Species other than D. latum probably constitute transitory intestinal infections in humans, usually lasting for only a few months. Although many carriers are asymptomatic, overt clinical manifestations of diphyllobothriasis can include diarrhea, epigastric pain, nausea and vomiting. There are no reports of anaemia associated with any of the northern species except D. latum. Effective control for diphyllobothriasis originating from D. latum has been achieved in many areas by a combination of selective drug therapy and improved sewage treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Human parasites in the Roman World: health consequences of conquering an empire.

    PubMed

    Mitchell, Piers D

    2017-01-01

    The archaeological evidence for parasites in the Roman era is presented in order to demonstrate the species present at that time, and highlight the health consequences for people living under Roman rule. Despite their large multi-seat public latrines with washing facilities, sewer systems, sanitation legislation, fountains and piped drinking water from aqueducts, we see the widespread presence of whipworm (Trichuris trichiura), roundworm (Ascaris lumbricoides) and Entamoeba histolytica that causes dysentery. This would suggest that the public sanitation measures were insufficient to protect the population from parasites spread by fecal contamination. Ectoparasites such as fleas, head lice, body lice, pubic lice and bed bugs were also present, and delousing combs have been found. The evidence fails to demonstrate that the Roman culture of regular bathing in the public baths reduced the prevalence of these parasites. Fish tapeworm was noted to be widely present, and was more common than in Bronze and Iron Age Europe. It is possible that the Roman enthusiasm for fermented, uncooked fish sauce (garum) may have facilitated the spread of this helminth. Roman medical practitioners such as Galen were aware of intestinal worms, explaining their existence and planning treatment using the humoural theory of the period.

  11. Adult somatic stem cells in the human parasite Schistosoma mansoni.

    PubMed

    Collins, James J; Wang, Bo; Lambrus, Bramwell G; Tharp, Marla E; Iyer, Harini; Newmark, Phillip A

    2013-02-28

    Schistosomiasis is among the most prevalent human parasitic diseases, affecting more than 200 million people worldwide. The aetiological agents of this disease are trematode flatworms (Schistosoma) that live and lay eggs within the vasculature of the host. These eggs lodge in host tissues, causing inflammatory responses that are the primary cause of morbidity. Because these parasites can live and reproduce within human hosts for decades, elucidating the mechanisms that promote their longevity is of fundamental importance. Although adult pluripotent stem cells, called neoblasts, drive long-term homeostatic tissue maintenance in long-lived free-living flatworms (for example, planarians), and neoblast-like cells have been described in some parasitic tapeworms, little is known about whether similar cell types exist in any trematode species. Here we describe a population of neoblast-like cells in the trematode Schistosoma mansoni. These cells resemble planarian neoblasts morphologically and share their ability to proliferate and differentiate into derivatives of multiple germ layers. Capitalizing on available genomic resources and RNA-seq-based gene expression profiling, we find that these schistosome neoblast-like cells express a fibroblast growth factor receptor orthologue. Using RNA interference we demonstrate that this gene is required for the maintenance of these neoblast-like cells. Our observations indicate that adaptation of developmental strategies shared by free-living ancestors to modern-day schistosomes probably contributed to the success of these animals as long-lived obligate parasites. We expect that future studies deciphering the function of these neoblast-like cells will have important implications for understanding the biology of these devastating parasites.

  12. Endoparasites of fat-tailed mouse opossums (Thylamys: Didelphidae) from northwestern Argentina and southern Bolivia, with the description of a new species of tapeworm.

    PubMed

    Jiménez, F Agustín; Braun, Janet K; Campbell, Mariel L; Gardner, Scott L

    2008-10-01

    The parasite fauna of 2 species of fat-tailed mouse opossums from northwestern Argentina is herein presented. Five species of helminths were found, i.e., Pterygodermatites kozeki, Hoineffia simplispicula, Oligacanthorhynchus sp., and a new species of tapeworm, Mathevotaenia sanmartini n. sp. (Cyclophyllidea: Anoplocephalidae). The new species is characterized by a calyciform scolex, relatively few testes (32), and a long cirrus sac; it occurs in fat-tailed mouse opossums at localities above 4,000 m. Those characters make it different from 6 species known to occur in marsupials from the New World, and from other species occurring in armadillos and bats. Didelphoxyuris thylamisis, H. simplicispicula, and Oligacanthorhynchus sp. appear to occur in marmosas from the Yungas region. In contrast, both P. kozeki and M. sanmartini n. sp. appear to occur exclusively in the Puna.

  13. Fossils of parasites: what can the fossil record tell us about the evolution of parasitism?

    PubMed

    Leung, Tommy L F

    2017-02-01

    Parasites are common in many ecosystems, yet because of their nature, they do not fossilise readily and are very rare in the geological record. This makes it challenging to study the evolutionary transition that led to the evolution of parasitism in different taxa. Most studies on the evolution of parasites are based on phylogenies of extant species that were constructed based on morphological and molecular data, but they give us an incomplete picture and offer little information on many important details of parasite-host interactions. The lack of fossil parasites also means we know very little about the roles that parasites played in ecosystems of the past even though it is known that parasites have significant influences on many ecosystems. The goal of this review is to bring attention to known fossils of parasites and parasitism, and provide a conceptual framework for how research on fossil parasites can develop in the future. Despite their rarity, there are some fossil parasites which have been described from different geological eras. These fossils include the free-living stage of parasites, parasites which became fossilised with their hosts, parasite eggs and propagules in coprolites, and traces of pathology inflicted by parasites on the host's body. Judging from the fossil record, while there were some parasite-host relationships which no longer exist in the present day, many parasite taxa which are known from the fossil record seem to have remained relatively unchanged in their general morphology and their patterns of host association over tens or even hundreds of millions of years. It also appears that major evolutionary and ecological transitions throughout the history of life on Earth coincided with the appearance of certain parasite taxa, as the appearance of new host groups also provided new niches for potential parasites. As such, fossil parasites can provide additional data regarding the ecology of their extinct hosts, since many parasites have

  14. 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.

  15. Molecular phylogeny based on six nuclear genes suggests that Echinococcus granulosus sensu lato genotypes G6/G7 and G8/G10 can be regarded as two distinct species.

    PubMed

    Laurimäe, Teivi; Kinkar, Liina; Moks, Epp; Romig, Thomas; Omer, Rihab A; Casulli, Adriano; Umhang, Gérald; Bagrade, Guna; Irshadullah, Malik; Sharbatkhori, Mitra; Mirhendi, Hossein; Ponce-Gordo, Francisco; Soriano, Silvia V; Varcasia, Antonio; Rostami-Nejad, Mohammad; Andresiuk, Vanessa; Saarma, Urmas

    2018-05-21

    Tapeworms of the species complex of Echinococcus granulosus sensu lato (s. l.) are the cause of a severe zoonotic disease - cystic echinococcosis, which is listed among the most severe parasitic diseases in humans and is prioritized by the World Health Organization. A stable taxonomy of E. granulosus s. l. is essential to the medical and veterinary communities for accurate and effective communication of the role of different species in this complex on human and animal health. E. granulosus s. l. displays high genetic diversity and has been divided into different species and genotypes. Despite several decades of research, the taxonomy of E. granulosus s. l. has remained controversial, especially the species status of genotypes G6-G10. Here the Bayesian phylogeny based on six nuclear loci (7387 bp in total) demonstrated, with very high support, the clustering of G6/G7 and G8/G10 into two separate clades. According to the evolutionary species concept, G6/G7 and G8/G10 can be regarded as two distinct species. Species differentiation can be attributed to the association with distinct host species, largely separate geographical distribution and low level of cross-fertilization. These factors have limited the gene flow between genotypic groups G6/G7 and G8/G10, resulting in the formation of distinct species. We discuss ecological and epidemiological differences that support the validity of these species.

  16. Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications.

    PubMed

    Tóth, Peter; Undas, Anna K; Verstappen, Francel; Bouwmeester, Harro

    2016-01-01

    The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae), are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs), consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae.

  17. Kinetoplastid phylogenetics, with special reference to the evolution of parasitic trypanosomes.

    PubMed

    Stevens, J R

    2008-09-01

    To fully understand the evolutionary history of parasitic kinetoplastids and to understand the context within which the evolution of each parasite group has developed, an understanding not just of the parasites, but of all kinetoplastids is required. Accordingly, this paper provides an overview of kinetoplastid evolution and systematics, including coverage of the proposal by Moreira et al. (2004) to divide kinetoplasts into Prokinetoplastina (Ichthyobodo and Perkinsiella) and Metakinetoplastina (other bodonids and trypanosomatids). The implications of such a revision, with regard to correctly identifying outgroup taxa for studies of evolution within taxa of medical importance, are addressed, together with a more detailed review of the evolution and origins of the trypanosomes in the light of new phylogenies, new approaches and revisions in kinetoplastid systematics.

  18. The utility of mtDNA and rDNA for barcoding and phylogeny of plant-parasitic nematodes from Longidoridae (Nematoda, Enoplea).

    PubMed

    Palomares-Rius, J E; Cantalapiedra-Navarrete, C; Archidona-Yuste, A; Subbotin, S A; Castillo, P

    2017-09-07

    The traditional identification of plant-parasitic nematode species by morphology and morphometric studies is very difficult because of high morphological variability that can lead to considerable overlap of many characteristics and their ambiguous interpretation. For this reason, it is essential to implement approaches to ensure accurate species identification. DNA barcoding aids in identification and advances species discovery. This study sought to unravel the use of the mitochondrial marker cytochrome c oxidase subunit 1 (coxI) as barcode for Longidoridae species identification, and as a phylogenetic marker. The results showed that mitochondrial and ribosomal markers could be used as barcoding markers, except for some species from the Xiphinema americanum group. The ITS1 region showed a promising role in barcoding for species identification because of the clear molecular variability among species. Some species presented important molecular variability in coxI. The analysis of the newly provided sequences and the sequences deposited in GenBank showed plausible misidentifications, and the use of voucher species and topotype specimens is a priority for this group of nematodes. The use of coxI and D2 and D3 expansion segments of the 28S rRNA gene did not clarify the phylogeny at the genus level.

  19. Ancient Human Parasites in Ethnic Chinese Populations.

    PubMed

    Yeh, Hui-Yuan; Mitchell, Piers D

    2016-10-01

    Whilst archaeological evidence for many aspects of life in ancient China is well studied, there has been much less interest in ancient infectious diseases, such as intestinal parasites in past Chinese populations. Here, we bring together evidence from mummies, ancient latrines, and pelvic soil from burials, dating from the Neolithic Period to the Qing Dynasty, in order to better understand the health of the past inhabitants of China and the diseases endemic in the region. Seven species of intestinal parasite have been identified, namely roundworm, whipworm, Chinese liver fluke, oriental schistosome, pinworm, Taenia sp. tapeworm, and the intestinal fluke Fasciolopsis buski . It was found that in the past, roundworm, whipworm, and Chinese liver fluke appear to have been much more common than the other species. While roundworm and whipworm remained common into the late 20th century, Chinese liver fluke seems to have undergone a marked decline in its prevalence over time. The iconic transport route known as the Silk Road has been shown to have acted as a vector for the transmission of ancient diseases, highlighted by the discovery of Chinese liver fluke in a 2,000 year-old relay station in northwest China, 1,500 km outside its endemic range.

  20. A new phylogeny and environmental DNA insight into paramyxids: an increasingly important but enigmatic clade of protistan parasites of marine invertebrates.

    PubMed

    Ward, Georgia M; Bennett, Martyn; Bateman, Kelly; Stentiford, Grant D; Kerr, Rose; Feist, Stephen W; Williams, Suzanne T; Berney, Cedric; Bass, David

    2016-09-01

    Paramyxida is an order of rhizarian protists that parasitise marine molluscs, annelids and crustaceans. They include notifiable pathogens (Marteilia spp.) of bivalves and other taxa of economic significance for shellfish production. The diversity of paramyxids is poorly known, particularly outside of commercially important hosts, and their phylogenetic position is unclear due to their extremely divergent 18S rDNA sequences. However, novel paramyxean lineages are increasingly being detected in a wide range of invertebrate hosts, and interest in the group is growing, marked by the first 'Paramyxean Working Group' Meeting held in Spain in February 2015. We review the diversity, host affiliations, and geographical ranges of all known paramyxids, present a comprehensive phylogeny of the order and clarify its taxonomy. Our phylogenetic analyses confirm the separate status of four genera: Paramarteilia, Marteilioides, Paramyxa and Marteilia. Further, as including M. granula in Marteilia would make the genus paraphyletic we suggest transferring this species to a new genus, Eomarteilia. We present sequence data for Paramyxa nephtys comb. n., a parasite of polychaete worms, providing morphological data for a clade of otherwise environmental sequences, sister to Marteilioides. Light and electron microscopy analyses show strong similarities with both Paramyxa and Paramyxoides, and we further discuss the validity of those two genera. We provide histological and electron microscopic data for Paramarteilia orchestiae, the type species of that genus originally described from the amphipod Orchestia; in situ hybridisation shows that Paramarteilia also infects crab species. We present, to our knowledge, the first known results of a paramyxid-specific environmental DNA survey of environmental (filtered water, sediment, etc.) and organismally-derived samples, revealing new lineages and showing that paramyxids are associated with a wider range of hosts and habitat types than previously

  1. Molecular characterization of Atractolytocestus sagittatus (Cestoda: Caryophyllidea), monozoic parasite of common carp, and its differentiation from the invasive species Atractolytocestus huronensis.

    PubMed

    Bazsalovicsová, Eva; Králová-Hromadová, Ivica; Stefka, Jan; Scholz, Tomáš

    2012-05-01

    Sequence structure of complete internal transcribed spacer 1 and 2 (ITS1 and ITS2) of the ribosomal DNA region and partial mitochondrial cytochrome c oxidase subunit I (cox1) gene sequences were studied in the monozoic tapeworm Atractolytocestus sagittatus (Kulakovskaya et Akhmerov, 1965) (Cestoda: Caryophyllidea), a parasite of common carp (Cyprinus carpio carpio L.). Intraindividual sequence diversity was observed in both ribosomal spacers. In ITS1, a total number of 19 recombinant clones yielded eight different sequence types (pairwise sequence identity, 99.7-100%) which, however, did not resemble the structure typical for divergent intragenomic ITS copies (paralogues). Polymorphism was displayed by several single nucleotide mutations present exclusively in single clones, but variation in the number of short repetitive motifs was not observed. In ITS2, a total of 21 recombinant clones yielded ten different sequence types (pairwise sequence identity, 97.5-100%). They were mostly characterized by a varying number of (TCGT)(n) repeats resulting in assortment of ITS2 sequences into two sequence variants, which reflected the structure specific for ITS paralogues. The third DNA region analysed, mitochondrial cox1 gene (669 bp) was detected to be 100% identical in all studied A. sagittatus individuals. Comparison of molecular data on A. sagittatus with those on Atractolytocestus huronensis Anthony, 1958, an invasive parasite of common carp, has shown that interspecific differences significantly exceeded intraspecific variation in both ribosomal spacers (81.4-82.5% in ITS1, 74.4-75.2% in ITS2) as well as in mitochondrial cox1, which confirms validity of both congeneric tapeworms parasitic in the same fish host.

  2. Triggering immunological memory against the tapeworm Hymenolepis diminuta to protect against colitis.

    PubMed

    Wang, A; Arai, T; Campbell, A; Reyes, J L; Lopes, F; McKay, D M

    2017-11-01

    Infection with parasitic helminths can ameliorate the severity of concomitant inflammatory disease. To use the tapeworm, Hymenolepis diminuta, and to extend this concept by assessing whether triggering a memory response against the worm inhibits dinitrobenzene sulphonic acid (DNBS)-induced colitis in Balb/c mice. Initial studies revealed that oral infection with 1, 3 or 5 H. diminuta cysticercoids 8 days before intrarectal administration of DNBS (3 mg) resulted in less severe inflammation and that infected mice displayed an increased propensity for T helper-2 immunity. A 1 mg dose of a PBS-soluble extract of the worm (HdAg) delivered intraperitoneally concomitant with DNBS was anticolitic as determined by macroscopic and histological disease scores 72 hour post-DNBS. Mice infected 28 days previously had a memory response as determined by HdAg-evoked increases in interleukin (IL)-4 and IL-10 from in vitro stimulated splenocytes and serum anti-H. diminuta IgG. Moreover, mice infected with 5 H. diminuta 28 days previously were protected from DNBS-induced colitis by secondary infection or 100 μg HdAg (ip.) at the time of DNBS treatment. An additional approach to managing inflammatory disease could be infection with H. diminuta followed by eliciting antiworm recall responses. © 2017 John Wiley & Sons Ltd.

  3. Floriparicapitus, a new genus of lecanicephalidean tapeworm (Cestoda) from sawfishes (Pristidae) and guitarfishes (Rhinobatidae) in the Indo-West Pacific.

    PubMed

    Cielocha, Joanna J; Jensen, Kirsten; Caira, Janine N

    2014-08-01

    Floriparicapitus n. gen. (Cestoda: Lecanicephalidea), with Floriparicapitus euzeti n. gen., n. sp. as its type, is erected to house 3 new tapeworm species and 2 known species that are transferred to the new genus, all parasitizing sawfishes and guitarfishes (order Rhinopristiformes) in Indo-Pacific waters. The new genus differs from the 21 valid lecanicephalidean genera in its possession of a large scolex bearing a laterally expanded apical organ in the form of a rugose sheet in combination with a cirrus conspicuously armed with spinitriches and 3 pairs of excretory vessels. It most closely resembles Lecanicephalum, but differs conspicuously in its possession of 3, rather than 1, pair of excretory vessels. Two new species are described from sawfishes: Floriparicapitus euzeti n. sp., from Pristis clavata and Floriparicapitus juliani n. sp. from Pristis pristis, both from Australia. Floriparicapitus plicatilis n. sp. is described from the guitarfish Glaucostegus typus in Australia and the guitarfish Glaucostegus thouin in Malaysian Borneo. Two species formerly assigned to Cephalobothrium are transferred to the new genus; Floriparicapitus variabilis ( Southwell, 1911 ) n. comb. from the sawfish Anoxypristis cuspidata in Sri Lanka and Floriparicapitus rhinobatidis ( Subhapradha, 1955 ) n. comb. from the guitarfish Glaucostegus granulatus in India. The species from guitarfish differ conspicuously from those parasitizing sawfish in their possession of only 4 ( F. plicatilis n. sp.) or 5 (F. rhinobatidis n. comb.) testes per proglottid versus 9 or more in the 3 sawfish-parasitizing species. The latter 3 species differ from one another in scolex width, acetabular size, number of proglottids, and cirrus sac size. As it stands, the new genus appears to be restricted to a subclade of the Rhinopristiformes consisting of the sawfishes and species of Glaucostegus.

  4. A few good reasons why species-area relationships do not work for parasites.

    PubMed

    Strona, Giovanni; Fattorini, Simone

    2014-01-01

    Several studies failed to find strong relationships between the biological and ecological features of a host and the number of parasite species it harbours. In particular, host body size and geographical range are generally only weak predictors of parasite species richness, especially when host phylogeny and sampling effort are taken into account. These results, however, have been recently challenged by a meta-analytic study that suggested a prominent role of host body size and range extent in determining parasite species richness (species-area relationships). Here we argue that, in general, results from meta-analyses should not discourage researchers from investigating the reasons for the lack of clear patterns, thus proposing a few tentative explanations to the fact that species-area relationships are infrequent or at least difficult to be detected in most host-parasite systems. The peculiar structure of host-parasite networks, the enemy release hypothesis, the possible discrepancy between host and parasite ranges, and the evolutionary tendency of parasites towards specialization may explain why the observed patterns often do not fit those predicted by species-area relationships.

  5. 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.

  6. A phylogeny of Cichlidogyrus spp. (Monogenea, Dactylogyridea) clarifies a host-switch between fish families and reveals an adaptive component to attachment organ morphology of this parasite genus.

    PubMed

    Messu Mandeng, Françoise D; Bilong Bilong, Charles F; Pariselle, Antoine; Vanhove, Maarten P M; Bitja Nyom, Arnold R; Agnèse, Jean-François

    2015-11-10

    Parasite switches to new host species are of fundamental scientific interest and may be considered an important speciation mechanism. For numerous monogenean fish parasites, infecting different hosts is associated with morphological adaptations, in particular of the attachment organ (haptor). However, haptoral morphology in Cichlidogyrus spp. (Monogenea, Dactylogyridea), parasites of African cichlids, has been mainly linked to phylogenetic rather than to host constraints. Here we determined the position of Cichlidogyrus amieti, a parasite of species of Aphyosemion (Cyprinodontiformes, Nothobranchiidae) in the phylogeny of its congeners in order to infer its origin and assess the morphological changes associated with host-switching events. The DNA of specimens of C. amieti isolated from Aphyosemion cameronense in Cameroon was sequenced and analyzed together with that of Cichlidogyrus spp. from cichlid hosts. In order to highlight the influence of the lateral transfer of C. amieti on the haptoral sclerotised parts we performed a Principal Component Analysis (PCA) to compare the attachment organ structure of C. amieti to that of congeners infecting cichlids. Cichlidogyrus amieti was found to be nested within a strongly supported clade of species described from Hemichromis spp. (i.e. C. longicirrus and C. dracolemma). This clade is located at a derived position of the tree, suggesting that C. amieti transferred from cichlids to Cyprinodontiformes and not inversely. The morphological similarity between features of their copulatory organs suggested that C. amieti shares a recent ancestor with C. dracolemma. It also indicates that in this case, these organs do not seem subjected to strong divergent selection pressure. On the other hand, there are substantial differences in haptoral morphology between C. amieti and all of its closely related congeners described from Hemichromis spp.. Our study provides new evidence supporting the hypothesis of the adaptive nature of haptor

  7. 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.

  8. 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.

  9. 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.

  10. Taenia solium Cysticercosis Hotspots Surrounding Tapeworm Carriers: Clustering on Human Seroprevalence but Not on Seizures

    PubMed Central

    Lescano, Andres G.; Garcia, Hector H.; Gilman, Robert H.; Gavidia, Cesar M.; Tsang, Victor C. W.; Rodriguez, Silvia; Moulton, Lawrence H.; Villaran, Manuel V.; Montano, Silvia M.; Gonzalez, Armando E.

    2009-01-01

    Background Neurocysticercosis accounts for 30%–50% of all late-onset epilepsy in endemic countries. We assessed the clustering patterns of Taenia solium human cysticercosis seropositivity and seizures around tapeworm carriers in seven rural communities in Peru. Methodology The presence of T. solium–specific antibodies was defined as one or more positive bands in the enzyme-linked immunoelectrotransfer blot (EITB). Neurocysticercosis-related seizures cases were diagnosed clinically and had positive neuroimaging or EITB. Principal Findings Eleven tapeworm carriers were identified by stool microscopy. The seroprevalence of human cysticercosis was 24% (196/803). Seroprevalence was 21% >50 m from a carrier and increased to 32% at 1–50 m (p = 0.047), and from that distance seroprevalence had another significant increase to 64% at the homes of carriers (p = 0.004). Seizure prevalence was 3.0% (25/837) but there were no differences between any pair of distance ranges (p = 0.629, Wald test 2 degrees of freedom). Conclusion/Significance We observed a significant human cysticercosis seroprevalence gradient surrounding current tapeworm carriers, although cysticercosis-related seizures did not cluster around carriers. Due to differences in the timing of the two outcomes, seroprevalence may reflect recent T. solium exposure more accurately than seizure frequency. PMID:19172178

  11. Genetics of the Pig Tapeworm in Madagascar Reveal a History of Human Dispersal and Colonization

    PubMed Central

    Yanagida, Tetsuya; Carod, Jean-François; Sako, Yasuhito; Nakao, Minoru; Hoberg, Eric P.; Ito, Akira

    2014-01-01

    An intricate history of human dispersal and geographic colonization has strongly affected the distribution of human pathogens. The pig tapeworm Taenia solium occurs throughout the world as the causative agent of cysticercosis, one of the most serious neglected tropical diseases. Discrete genetic lineages of T. solium in Asia and Africa/Latin America are geographically disjunct; only in Madagascar are they sympatric. Linguistic, archaeological and genetic evidence has indicated that the people in Madagascar have mixed ancestry from Island Southeast Asia and East Africa. Hence, anthropogenic introduction of the tapeworm from Southeast Asia and Africa had been postulated. This study shows that the major mitochondrial haplotype of T. solium in Madagascar is closely related to those from the Indian Subcontinent. Parasitological evidence presented here, and human genetics previously reported, support the hypothesis of an Indian influence on Malagasy culture coinciding with periods of early human migration onto the island. We also found evidence of nuclear-mitochondrial discordance in single tapeworms, indicating unexpected cross-fertilization between the two lineages of T. solium. Analyses of genetic and geographic populations of T. solium in Madagascar will shed light on apparently rapid evolution of this organism driven by recent (<2,000 yr) human migrations, following tens of thousands of years of geographic isolation. PMID:25329310

  12. 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 ...

  13. Influence of host diet and phylogeny on parasite sharing by fish in a diverse tropical floodplain.

    PubMed

    Lima, L B; Bellay, S; Giacomini, H C; Isaac, A; Lima-Junior, D P

    2016-03-01

    The patterns of parasite sharing among hosts have important implications for ecosystem structure and functioning, and are influenced by several ecological and evolutionary factors associated with both hosts and parasites. Here we evaluated the influence of fish diet and phylogenetic relatedness on the pattern of infection by parasites with contrasting life history strategies in a freshwater ecosystem of key ecological importance in South America. The studied network of interactions included 52 fish species, which consumed 58 food types and were infected with 303 parasite taxa. Our results show that both diet and evolutionary history of hosts significantly explained parasite sharing; phylogenetically close fish species and/or species sharing food types tend to share more parasites. However, the effect of diet was observed only for endoparasites in contrast to ectoparasites. These results are consistent with the different life history strategies and selective pressures imposed on these groups: endoparasites are in general acquired via ingestion by their intermediate hosts, whereas ectoparasites actively seek and attach to the gills, body surface or nostrils of its sole host, thus not depending directly on its feeding habits.

  14. A monkey's tale: The origin of Plasmodium vivax as a human malaria parasite

    PubMed Central

    Escalante, Ananias A.; Cornejo, Omar E.; Freeland, Denise E.; Poe, Amanda C.; Durrego, Ester; Collins, William E.; Lal, Altaf A.

    2005-01-01

    The high prevalence of Duffy negativity (lack of the Duffy blood group antigen) among human populations in sub-Saharan Africa has been used to argue that Plasmodium vivax originated on that continent. Here, we investigate the phylogenetic relationships among 10 species of Plasmodium that infect primates by using three genes, two nuclear (β-tubulin and cell division cycle 2) and a gene from the plastid genome (the elongation factor Tu). We find compelling evidence that P. vivax is derived from a species that inhabited macaques in Southeast Asia. Specifically, those phylogenies that include P. vivax as an ancient lineage from which all of the macaque parasites could originate are significantly less likely to explain the data. We estimate the time to the most recent common ancestor at four neutral gene loci from Asian and South American isolates (a minimum sample of seven isolates per locus). Our analysis estimates that the extant populations of P. vivax originated between 45,680 and 81,607 years ago. The phylogeny and the estimated time frame for the origination of current P. vivax populations are consistent with an “out of Asia” origin for P. vivax as hominoid parasite. The current debate regarding how the Duffy negative trait became fixed in Africa needs to be revisited, taking into account not only human genetic data but also the genetic diversity observed in the extant P. vivax populations and the phylogeny of the genus Plasmodium. PMID:15684081

  15. Evaluation of anthelmintic potential of the Ethiopian medicinal plant Embelia schimperi Vatke in vivo and in vitro against some intestinal parasites.

    PubMed

    Debebe, Yared; Tefera, Mesfin; Mekonnen, Walelign; Abebe, Dawit; Woldekidan, Samuel; Abebe, Abiy; Belete, Yehualashet; Menberu, Temesgen; Belayneh, Bethelhem; Tesfaye, Berhanu; Nasir, Ibrahim; Yirsaw, Kidist; Basha, Hirut; Dawit, Asrat; Debella, Asfaw

    2015-06-18

    Embelia schimperi has been used for the treatment of intestinal parasites especially tapeworm infestations for centuries in Ethiopia. However, there is lack of scientific based evidences regarding the efficacy, safety and phytochemical analysis of this plant despite its frequent use as an anthelmintic. This study has therefore evaluated the efficacy and acute toxicity of E. schimperi thereby generating relevant preclinical information. The anthelmintic activities of the crude hydroalcoholic extract of E. schimperi and the isolated compound, embelin, were conducted using in vivo and in vitro models against the dwarf tapeworm, Hymenolepis nana, and the hookworm, Necator americanus, respectively. LD50 of the crude hydroalcoholic extract was determined using Swiss albino mice following the OECD guidelines. Chemical characterization of the isolated embelin was conducted using UV-spectroscopy, HPLC and NMR. In the acute toxicity study no prominent signs of toxicity and mortality were recorded among the experimental animals at the highest administered dose. Hence the LD50 of the plant was found to be higher than 5000 mg/kg. In vivo cestocidal activity of the crude hydroalcoholic extract of E. schimperi showed 100% parasite clearance at 1000 mg/kg, while the diammonium salt of embelin showed 85.3% parasite clearance at 750 mg/kg. The in vitro anthelminthic activity study revealed that the LC50 value of the crude extract and albendazole were 228.7 and 51.33 μg/mL, respectively. The results clearly indicated that the hydroalcoholic extract of E. schimperi and the diammonium salt of the isolated compound embelin had anthelmintic activity against hookworm larva in vitro and H. nana in vivo. Hence the findings of this study showed Embelia schimperi appears to possess some anthelmintic activity that may support the usage of these plants by local traditional healers to treat helminthic infestations.

  16. Lifetime inbreeding depression, purging, and mating system evolution in a simultaneous hermaphrodite tapeworm.

    PubMed

    Benesh, Daniel P; Weinreich, Friederike; Kalbe, Martin; Milinski, Manfred

    2014-06-01

    Classical theory on mating system evolution suggests that simultaneous hermaphrodites should either outcross if they have high inbreeding depression (ID) or self-fertilize if they have low ID. However, a mixture of selfing and outcrossing persists in many species. Previous studies with the tapeworm Schistocephalus solidus have found worms to self-fertilize some of their eggs despite ID. The probability for selfing to spread depends on the relative fitness of selfers, as well as the genetic basis for ID and whether it can be effectively purged. We bred S. solidus through two consecutive generations of selfing and recorded several fitness correlates over the whole life cycle. After one round of selfing, ID was pronounced, particularly in early-life traits, and the conservatively estimated lifetime fitness of selfed progeny was only 9% that of the outcrossed controls. After a second generation of selfing, ID remained high but was significantly reduced in several traits, which is consistent with the purging of deleterious recessive alleles (the estimated load of lethal equivalents dropped by 48%). Severe ID, even if it can be rapidly purged, likely prevents transitions toward pure selfing in this parasite, although we also cannot exclude the possibility that low-level selfing has undetected benefits. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  17. Plastid genome structure and loss of photosynthetic ability in the parasitic genus Cuscuta.

    PubMed

    Revill, Meredith J W; Stanley, Susan; Hibberd, Julian M

    2005-09-01

    The genus Cuscuta (dodder) is composed of parasitic plants, some species of which appear to be losing the ability to photosynthesize. A molecular phylogeny was constructed using 15 species of Cuscuta in order to assess whether changes in photosynthetic ability and alterations in structure of the plastid genome relate to phylogenetic position within the genus. The molecular phylogeny provides evidence for four major clades within Cuscuta. Although DNA blot analysis showed that Cuscuta species have smaller plastid genomes than tobacco, and that plastome size varied significantly even within one Cuscuta clade, dot blot analysis indicated that the dodders possess homologous sequence to 101 genes from the tobacco plastome. Evidence is provided for significant rates of DNA transfer from plastid to nucleus in Cuscuta. Size and structure of Cuscuta plastid genomes, as well as photosynthetic ability, appear to vary independently of position within the phylogeny, thus supporting the hypothesis that within Cuscuta photosynthetic ability and organization of the plastid genome are changing in an unco-ordinated manner.

  18. An endemic Taenia from South America: validation of T. Talicei Dollfus, 1960 (Cestoda: Taeniidae) with characterization of metacestodes and adults

    USDA-ARS?s Scientific Manuscript database

    Taeniid tapeworms are characteristic parasites in both domesticated and wild carnivores and life cycles are completed through predator-prey associations with rodent, lagomorph or ungulate intermediate hosts that harbor infective larvae. Globally these tapeworms contribute to morbidity and mortality ...

  19. Persistence of host defence behaviour in the absence of avian brood parasitism

    PubMed Central

    Peer, Brian D.; Kuehn, Michael J.; Rothstein, Stephen I.; Fleischer, Robert C.

    2011-01-01

    The fate of host defensive behaviour in the absence of selection from brood parasitism is critical to long-term host–parasite coevolution. We investigated whether New World Bohemian waxwings Bombycilla garrulus that are allopatric from brown-headed cowbird Molothrus ater and common cuckoo Cuculus canorus parasitism have retained egg rejection behaviour. We found that egg rejection was expressed by 100 per cent of Bohemian waxwings. Our phylogeny revealed that Bohemian and Japanese waxwings Bombycilla japonica were sister taxa, and this clade was sister to the cedar waxwing Bombycilla cedrorum. In addition, there was support for a split between Old and New World Bohemian waxwings. Our molecular clock estimates suggest that egg rejection may have been retained for 2.8–3.0 Myr since New World Bohemian waxwings inherited it from their common ancestor with the rejecter cedar waxwings. These results support the ‘single trajectory’ model of host–brood parasite coevolution that once hosts evolve defences, they are retained, forcing parasites to become more specialized over time. PMID:21493623

  20. Effects of larval tapeworm (Taenia taeniaeformis) infection on reproductive functions in male and female host rats.

    PubMed

    Lin, Y C; Rikihisa, Y; Kono, H; Gu, Y

    1990-04-01

    This report examined the effects of larval tapeworm infection on the reproductive functions in both male and female host rats. Female rats were matched by age, then randomly assigned to control and treatment groups (infected with larval tapeworms). Estrous cycles were determined by vaginal smear with 95% of the control group exhibiting 4-day normal cyclicity and only 55% of the treated group exhibiting normal cycles. Female fertility was then evaluated for the normally cycling rats based on the percentage of successful matings on the evening of proestrus, number of implantation sites on Day 8 of pregnancy, and number of pups born at term. The normally cycling rats exhibited 96% successful mating, 12.95 +/- 1.80 implantation sites, and 11.20 +/- 1.80 pups born. Five months after larval tapeworm infection, the fertility parameters were decreased to 79%, 9.10 +/- 1.20, and 7.50 +/- 1.50, respectively. The control females were then used in a study of male fertility after larval tapeworm infection employing the same parameters used to test female fertility. At the onset of the study, control groups exhibited 95% successful mating, 12.50 +/- 1.50 implantation sites, and 11.60 +/- 1.60 pups born at full term. After the 5-month infection period, the parameters were substantially reduced to 29%, 6.20 +/- 0.80 implantation sites, and 5.10 +/- 0.80 pups, respectively. Average testosterone concentrations in serum and testis from control male rats were 8.80 +/- 0.95 ng/ml and 3.88 +/- 0.25 ng/mg protein, respectively. After the 5-month infection period, these levels were reduced to 2.47 +/- 0.31 ng/ml and 1.28 +/- 0.12 ng/mg protein, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Prevalence and differential host-specificity of two avian blood parasite genera in the Australo-Papuan region

    USGS Publications Warehouse

    Beadell, J.S.; Gering, E.; Austin, J.; Dumbacher, J.P.; Peirce, M.A.; Pratt, T.K.; Atkinson, C.T.; Fleischer, R.C.

    2004-01-01

    The degree to which widespread avian blood parasites in the genera Plasmodium and Haemoproteus pose a threat to novel hosts depends in part on the degree to which they are constrained to a particular host or host family. We examined the host distribution and host-specificity of these parasites in birds from two relatively understudied and isolated locations: Australia and Papua New Guinea. Using polymerase chain reaction (PCR), we detected infection in 69 of 105 species, representing 44% of individuals surveyed (n = 428). Across host families, prevalence of Haemoproteus ranged from 13% (Acanthizidae) to 56% (Petroicidae) while prevalence of Plasmodium ranged from 3% (Petroicidae) to 47% (Ptilonorhynchidae). We recovered 78 unique mitochondrial lineages from 155 sequences. Related lineages of Haemoproteus were more likely to derive from the same host family than predicted by chance at shallow (average LogDet genetic distance = 0, n = 12, P = 0.001) and greater depths (average distance = 0.014, n = 11, P < 0.001) within the parasite phylogeny. Within two major Haemoproteus subclades identified in a maximum likelihood phylogeny, host-specificity was evident up to parasite genetic distances of 0.029 and 0.007 based on logistic regression. We found no significant host relationship among lineages of Plasmodium by any method of analysis. These results support previous evidence of strong host-family specificity in Haemoproteus and suggest that lineages of Plasmodium are more likely to form evolutionarily-stable associations with novel hosts.

  2. A Human Case of Zoonotic Dog Tapeworm, Dipylidium caninum (Eucestoda: Dilepidiidae), in China

    PubMed Central

    Jiang, Peng; Zhang, Xi; Liu, Ruo Dan; Wang, Zhong Quan; Cui, Jing

    2017-01-01

    We described a human case of zoonotic dog tapeworm, Dipylidium caninum (Eucestoda: Dilepidiidae), rarely occurring in China. The mother of a 17 month-old boy noted the appearance of small white and active worms over a month period in her son’s feces, but the boy was asymptomatic except mild diarrhea. We observed 3 tapeworm proglottids resembling cucumber seeds in his stool sample. Microscopically, each proglottid had 2 genital pores, 1 on each lateral edge, and numerous egg capsules in the uterus. The patient was successfully treated with a single oral dose of praziquantel. Adult worms were recovered in the diarrheic stool after praziquantel treatment and purgation. His family had household pet dogs for several years, and he might have acquired the infection by ingestion of infected fleas of his pet dogs. A history of dog or cat pets and flea bites may be important clues to diagnosis of D. caninum infection. The infected pets should also be treated. PMID:28285500

  3. A Human Case of Zoonotic Dog Tapeworm, Dipylidium caninum (Eucestoda: Dilepidiidae), in China.

    PubMed

    Jiang, Peng; Zhang, Xi; Liu, Ruo Dan; Wang, Zhong Quan; Cui, Jing

    2017-02-01

    We described a human case of zoonotic dog tapeworm, Dipylidium caninum (Eucestoda: Dilepidiidae), rarely occurring in China. The mother of a 17 month-old boy noted the appearance of small white and active worms over a month period in her son's feces, but the boy was asymptomatic except mild diarrhea. We observed 3 tapeworm proglottids resembling cucumber seeds in his stool sample. Microscopically, each proglottid had 2 genital pores, 1 on each lateral edge, and numerous egg capsules in the uterus. The patient was successfully treated with a single oral dose of praziquantel. Adult worms were recovered in the diarrheic stool after praziquantel treatment and purgation. His family had household pet dogs for several years, and he might have acquired the infection by ingestion of infected fleas of his pet dogs. A history of dog or cat pets and flea bites may be important clues to diagnosis of D. caninum infection. The infected pets should also be treated.

  4. Molecular phylogeny of the Bothriocephalidea (Cestoda): molecular data challenge morphological classification.

    PubMed

    Brabec, Jan; Waeschenbach, Andrea; Scholz, Tomáš; Littlewood, D Timothy J; Kuchta, Roman

    2015-10-01

    In this study, the relationships of the cestode order Bothriocephalidea, parasites of marine and freshwater bony fish, were assessed using multi-gene molecular phylogenetic analyses. The dataset included 59 species, covering approximately 70% of currently recognised genera, a sample of bothriocephalidean biodiversity gathered through an intense 15year effort. The order as currently circumscribed, while monophyletic, includes three non-monophyletic and one monophyletic families. Bothriocephalidae is monophyletic and forms the most derived lineage of the order, comprised of a single freshwater and several marine clades. Biogeographic patterns within the freshwater clade are indicative of past radiations having occurred in Africa and North America. The earliest diverging lineages of the order comprise a paraphyletic Triaenophoridae. The Echinophallidae, consisting nearly exclusively of parasites of pelagic fish, was also resolved as paraphyletic with respect to the Bothriocephalidae. Philobythoides sp., the only representative included from the Philobythiidae, a unique family of parasites of bathypelagic fish, was sister to the genus Eubothrium, the latter constituting one of the lineages of the paraphyletic Triaenophoridae. Due to the weak statistical support for most of the basal nodes of the Triaenophoridae and Echinophallidae, as well as the lack of obvious morphological synapomorphies shared by taxa belonging to the statistically well-supported lineages, the current family-level classification, although mostly non-monophyletic, is provisionally retained, with the exception of the family Philobythiidae, which is recognised as a synonym of the Triaenophoridae. In addition, Schyzocotyle is resurrected to accommodate the invasive Asian fish tapeworm, Schyzocotyle acheilognathi (Yamaguti, 1934) n. comb. (syn. Bothriocephalus acheilognathi Yamaguti, 1934), which is of veterinary importance, and Schyzocotyle nayarensis (Malhotra, 1983) n. comb. (syn. Ptychobothrium

  5. Benefits of fidelity: does host specialization impact nematode parasite life history and fecundity?

    PubMed

    Koprivnikar, J; Randhawa, H S

    2013-04-01

    The range of hosts used by a parasite is influenced by macro-evolutionary processes (host switching, host-parasite co-evolution), as well as 'encounter filters' and 'compatibility filters' at the micro-evolutionary level driven by host/parasite ecology and physiology. Host specialization is hypothesized to result in trade-offs with aspects of parasite life history (e.g. reproductive output), but these have not been well studied. We used previously published data to create models examining general relationships among host specificity and important aspects of life history and reproduction for nematodes parasitizing animals. Our results indicate no general trade-off between host specificity and the average pre-patent period (time to first reproduction), female size, egg size, or fecundity of these nematodes. However, female size was positively related to egg size, fecundity, and pre-patent period. Host compatibility may thus not be the primary determinant of specificity in these parasitic nematodes if there are few apparent trade-offs with reproduction, but rather, the encounter opportunities for new host species at the micro-evolutionary level, and other processes at the macro-evolutionary level (i.e. phylogeny). Because host specificity is recognized as a key factor determining the spread of parasitic diseases understanding factors limiting host use are essential to predict future changes in parasite range and occurrence.

  6. Reciprocal cross infection of sticklebacks with the diphyllobothriidean cestode Schistocephalus solidus reveals consistent population differences in parasite growth and host resistance.

    PubMed

    Kalbe, Martin; Eizaguirre, Christophe; Scharsack, Jörn P; Jakobsen, Per J

    2016-03-08

    In host-parasite evolutionary arms races, parasites are generally expected to adapt more rapidly, due to their large population sizes and short generation times. There exist systems, though, where parasites cannot outpace their hosts because of similar generation times in both antagonists. In those cases concomitant adaptation is expected. We tested this hypothesis in the three-spined stickleback-Schistocephalus solidus tapeworm system, where generation times are comparable in both organisms. We chose two populations of sticklebacks which differ prominently in the prevalence of S. solidus and consequently in its level of selective pressure. We performed a full factorial common garden experiment. Particularly, Norwegian (NO) and German (DE) sticklebacks, as well as hybrids between both stickleback populations and in both parental combinations, were exposed each to a single S. solidus originating from the same two host populations. We found the infection phenotype to depend on the host population, the parasite population, but not their interaction. NO-parasites showed higher infectivity than DE-parasites, with NO-sticklebacks also being more resistant to DE-parasites than to the sympatric NO-parasite. Reciprocally, DE-hosts were more susceptible to the allopatric NO-parasite while DE-parasites grew less than NO-parasites in all stickleback groups. Despite this asymmetry, the ratio of worm to host weight, an indicator of parasite virulence, was identical in both sympatric combinations, suggesting an optimal virulence as a common outcome of parallel coevolved systems. In hybrid sticklebacks, intermediate infection rates and growth of S. solidus from either origin suggests a simple genetic basis of resistance. However, comparison of infection phenotypes in NO-maternal and DE-maternal hybrid sticklebacks indicates local adaptation to the sympatric counterpart in both the host and the parasite. Host-parasite systems with similar generation time show evidence for

  7. Parasitic infections and resource economy of Danish Iron Age settlement through ancient DNA sequencing.

    PubMed

    Tams, Katrine Wegener; Jensen Søe, Martin; Merkyte, Inga; Valeur Seersholm, Frederik; Henriksen, Peter Steen; Klingenberg, Susanne; Willerslev, Eske; Kjær, Kurt H; Hansen, Anders Johannes; Kapel, Christian Moliin Outzen

    2018-01-01

    In this study, we screen archaeological soil samples by microscopy and analyse the samples by next generation sequencing to obtain results with parasites at species level and untargeted findings of plant and animal DNA. Three separate sediment layers of an ancient man-made pond in Hoby, Denmark, ranging from 100 BC to 200 AD, were analysed by microscopy for presence of intestinal worm eggs and DNA analysis were performed to identify intestinal worms and dietary components. Ancient DNA of parasites, domestic animals and edible plants revealed a change in use of the pond over time reflecting the household practice in the adjacent Iron Age settlement. The most abundant parasite found belonged to the Ascaris genus, which was not possible to type at species level. For all sediment layers the presence of eggs of the human whipworm Trichuris trichiura and the beef tapeworm Taenia saginata suggests continuous disposal of human faeces in the pond. Moreover, the continuous findings of T. saginata further imply beef consumption and may suggest that cattle were living in the immediate surrounding of the site throughout the period. Findings of additional host-specific parasites suggest fluctuating presence of other domestic animals over time: Trichuris suis (pig), Parascaris univalens (horse), Taenia hydatigena (dog and sheep). Likewise, alternating occurrence of aDNA of edible plants may suggest changes in agricultural practices. Moreover, the composition of aDNA of parasites, plants and vertebrates suggests a significant change in the use of the ancient pond over a period of three centuries.

  8. Pasteuria spp.: Systematics and Phylogeny of These Bacterial Parasites of Phytopathogenic Nematodes.

    PubMed

    Preston, J F; Dickson, D W; Maruniak, J E; Nong, G; Brito, J A; Schmidt, L M; Giblin-Davis, R M

    2003-06-01

    Pasteuria spp. include endospore-forming bacterial pathogens of cladoceran crustaceans and plant-parasitic nematodes. Propagation of these nematode pathogens requires attachment of soilborne endospores to nematode hosts, infection, growth, sporulation, and release of endospores to repeat the cycle of infection and propagation. The ability of these bacteria to suppress the levels of plant-parasitic nematodes in the field has made them particularly promising candidates for biocontrol of nematode diseases of plants. Genes encoding 16S ribosomal RNA have been sequenced for the cladoceran (water flea) parasite and type species, Pasteuria ramosa, and for Pasteuria spp. isolated from root-knot (Meloidogyne arenaria race 1 and Meloidogyne sp.), soybean cyst (Heterodera glycines), and sting (Belonolaimus longicaudatus) nematodes. These have provided a phylogenetic basis for their designation to a distinct clade within the family Alicyclobacillaceae of the gram-positive endospore-forming bacteria. Two apparent biotypes of P. penetrans demonstrating a host preference for different Meloidogyne spp. showed identical 16S rDNA sequences, suggesting host-recognition evolves within a given species. The sequences of genes encoding sporulation transcription factors, sigE and sigF, from P. penetrans biotype P-20 show different phylogenetic relationships to other endospore-forming bacteria, supporting their application to further discriminate Pasteuria spp. and biotypes. Distribution of an adhesin-associated epitope on polypeptides from different Pasteuria isolates provides an immunochemical approach to differentiate species and biotypes with specific host preferences. Application of bioinformatics to genomic data, as well as further characterization of the biochemical basis for host recognition, will facilitate development of Pasteuria spp. as benign alternatives to chemical nematicides.

  9. Infection level of the Asian tapeworm (Bothriocephalus acheilognathi) in the cyprinid fish, Schizothorax niger, from Anchar Lake, relative to season, sex, length and condition factor.

    PubMed

    Zargar, Ummer Rashid; Chishti, M Z; Yousuf, A R; Ahmed, Fayaz

    2012-01-01

    Various studies have shown that the Asian fish tapeworm, Bothriocephalus acheilognathi causes great economic loss in hatcheries, fish farms as well as in lakes. In order to understand the seasonal variation of infection in a nutrient-enriched lake, parasitological investigation was carried out in the indigenous cyprinid fish, Schizothorax niger Heckel 1838 from September, 2008 to August, 2009. Overall, this study revealed definite seasonality of infection (p < 0.05), with greater infection in summer (prevalence = 39.5%) and lesser in winter (prevalence = 8.1%). The prevalence among different seasons revealed significant differences (p < 0.05). Sex was not an important factor influencing the prevalence of the Asian tapeworm. A strong positive correlation (Pearson's correlation, r = 0.7; p = 0.02) between total length of S. niger and number of Asian fish tapeworms was observed. Similarly, a strong positive correlation existed between weight of fish and number of tapeworms (Pearson's correlation, r = 0.7; p = 0.005). Prevalence and mean abundance were positively and significantly correlated with water temperature (r = 0.8, p < 0.01 and r = 0.8, p < 0.01, respectively). Thus seasonal dynamics, total length and weight of the host significantly influenced the tapeworm infection. The above findings will be useful in devising the appropriate control strategies for the Asian tapeworm in wild fish in Kashmir valley as well as in similar climatic zones of other parts of the world. Also, information from this study will be used to assess the spread and extent of B. acheilognathi which is a potential threat to the indigenous fish fauna of Anchar Lake.

  10. Diversity and distribution of parasitic angiosperms in China.

    PubMed

    Zhang, Guangfu; Li, Qian; Sun, Shucun

    2018-05-01

    Parasitic plants are an important component of vegetation worldwide, but their diversity and distribution in China have not been systematically reported. This study aimed to (1) explore floral characteristics of China's parasitic plants, (2) map spatial distribution of diversity of these species, and (3) explore factors influencing the distribution pattern. We compiled a nationwide species list of parasitic plants in China, and for each species, we recorded its phylogeny, endemism, and life form (e.g., herb vs. shrub; hemiparasite vs. holoparasite). Species richness and area-corrected species richness were calculated for 28 provinces, covering 98.89% of China's terrestrial area. Regression analyses were performed to determine relationships between provincial area-corrected species richness of parasitic plants and provincial total species richness (including nonparasitic plants) and physical settings (altitude, midlongitude, and midlatitude). A total of 678 species of parasitic angiosperms are recorded in China, 63.13% of which are endemic. Of the total, 59.73% (405 species) are perennials, followed by shrubs/subshrubs (14.75%) and vines (1.47%). About 76.11% (516 species) are of root hemiparasites, higher than that of stem parasites (100, 14.75%), root holoparasites (9.00%), and endophytic parasites (0.15%). A significant positive relationship is found between the area-corrected species richness and the total species richness, which has been previously demonstrated to increase with decreasing longitude and latitude. Moreover, more parasitic species are found in the southwest high-altitude areas than low areas. Consistently, the area-corrected species richness increases with increasing altitude, decreasing latitude, and decreasing longitude, as indicated by regression analyses. China is rich in parasitic flora with a high proportion of endemic species. Perennials and root hemiparasites are the dominant types. The spatial distribution of parasitic plants is largely

  11. A new combination and a new species of onchobothriid tapeworm (Cestoda: Tetraphyllidea: Onchobothriidae) from triakid sharks.

    PubMed

    Kurashima, Akira; Shimizu, Toshiya; Mano, Nobuhiro; Ogawa, Kazuo; Fujita, Toshihiko

    2014-05-01

    A new combination and a new species of onchobothriid tapeworm are described from triakid sharks. We found Platybothrium xiamenensis Wang & Yang, 2001 and Erudituncus musteli (Yamaguti, 1952) from Hemitriakis japanica (Müller & Henle). Based on the morphology of the hooks P. xiamenensis is transferred to the genus Erudituncus Healy, Scholz & Caira, 2001. The specimens studied by us differ from the original description in the number of proglottids and testes and in the size of the cirrus-sac. However, we consider them conspecific with E. xiamenensis due to the consistent hook morphology and laciniations in both descriptions and believe the differences reflect intraspecific variation. The type-host of E. xiamenensis was reported as Mustelus griseus Pietschmann. However, in the present study, this parasite was found only in H. japanica and never in M. griseus although many specimens of the latter host were examined. This suggests that the type-host in the original description has probably been misidentified. We found another undescribed species in M. griseus, Calliobothrium shirozame n. sp., which is distinguished from the congeners by having a unique combination of the number of laciniations: four in the cephalic peduncle, six in the immature proglottids and four in the mature proglottids.

  12. Parasites in the mangrove oyster Crassostrea rhizophorae cultivated in the estuary of the Graciosa River in Taperoá, Bahia.

    PubMed

    Cova, Aliane Watanabe; Serafim Júnior, Moacyr; Boehs, Guisla; Souza, Jackson Moreira de

    2015-01-01

    In this work, parasites associated with the mangrove oyster Crassostrea rhizophorae were studied at a cultivation unit in the estuary of the Graciosa River in Taperoá, Bahia. On a monthly basis, between April 2011 and March 2012, 20 oysters were collected, measured and fixed in 10% formaldehyde. In order to identify the parasites, routine histological techniques were used. The specimens were embedded in paraffin and sections, 7 µm thick, were cut. These were then stained with Harris hematoxylin and eosin and were examined using an optical microscope. The parameters analyzed to investigate water quality showed that the temperature ranged from 23.9 °C to 29.3 °C, water salinity from 0.4 to 24.2 Practical Salinity Units PSU and recorded rainfall from 80 mm to 406.4 mm/month. During the parasitological analyses, infestation of the polychaete Neanthes succinea was observed in 41% of the oysters. Through histological techniques, the following parasites were identified: colonies of Rickettsia-like organisms (RLOs); the protozoa Nematopsis sp. and Ancistrocoma sp.; the turbellarian Urastoma sp.; the metacestode Tylocephalum sp. and an unidentified tapeworm. The data collected showed that there was low-intensity infection with and prevalence of parasites, except for Nematopsis sp., thus attesting that these cultivated oysters were in a healthy condition.

  13. Return to Beringia: parasites reveal cryptic biogeographic history of North American pikas.

    PubMed

    Galbreath, Kurt E; Hoberg, Eric P

    2012-01-22

    Traditional concepts of the Bering Land Bridge as a zone of predominantly eastward expansion from Eurasia and a staging area for subsequent colonization of lower latitudes in North America led to early inferences regarding biogeographic histories of North American faunas, many of which remain untested. Here we apply a host-parasite comparative phylogeographical (HPCP) approach to evaluate one such history, by testing competing biogeographic hypotheses for five lineages of host-specific parasites shared by the collared pika (Ochotona collaris) and American pika (Ochotona princeps) of North America. We determine whether the southern host species (O. princeps) was descended from a northern ancestor or vice versa. Three parasite phylogenies revealed patterns consistent with the hypothesis of a southern origin, which is corroborated by four additional parasite lineages restricted to O. princeps. This finding reverses the traditional narrative for the origins of North American pikas and highlights the role of dispersal from temperate North America into Beringia in structuring northern diversity considerably prior to the Holocene. By evaluating multiple parasite lineages simultaneously, the study demonstrates the power of HPCP for resolving complex biogeographic histories that are not revealed by characteristics of the host alone.

  14. Emergence of new genotype and diversity of Theileria orientalis parasites from bovines in India.

    PubMed

    George, Neena; Bhandari, Vasundhra; Reddy, D Peddi; Sharma, Paresh

    2015-12-01

    Bovine theileriosis is a serious threat to livestock worldwide. Uncertainty around species prevalence, antigenic diversity and genotypes of strains make it difficult to assess the impact of this parasite and to provide necessary treatment. We aimed to characterize genotypic diversity, phylogeny and prevalence of Theileria orientalis parasites from the states of Telangana and Andhra Pradesh, India by collecting bovine blood samples from the major districts of the two states. Bioinformatic analysis identified antigenic diversity among the prevalent parasite strains using major piroplasm surface protein (MPSP) gene. Our study revealed a prevalence rate of 4.8% (n=41/862) of T. orientalis parasites in bovine animals and a new genotype of T. orientalis parasite which was not previously reported in India. The emergence of these new genotypes could be an explanation for the frequent outbreaks of bovine theileriosis. Further, whole genome sequencing of T. orientalis strains will help to elucidate the genetic factors relevant for transmissibility and virulence as well as vaccine and new drug development. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. A DNA and morphology based phylogenetic framework of the ant genus Lasius with hypotheses for the evolution of social parasitism and fungiculture.

    PubMed

    Maruyama, Munetoshi; Steiner, Florian M; Stauffer, Christian; Akino, Toshiharu; Crozier, Ross H; Schlick-Steiner, Birgit C

    2008-08-19

    Ants of the genus Lasius are ecologically important and an important system for evolutionary research. Progress in evolutionary research has been hindered by the lack of a well-founded phylogeny of the subgenera, with three previous attempts disagreeing. Here we employed two mitochondrial genes (cytochrome c oxidase subunit I, 16S ribosomal RNA), comprising 1,265 bp, together with 64 morphological characters, to recover the phylogeny of Lasius by Bayesian and Maximum Parsimony inference after exploration of potential causes of phylogenetic distortion. We use the resulting framework to infer evolutionary pathways for social parasitism and fungiculture. We recovered two well supported major lineages. One includes Acanthomyops, Austrolasius, Chthonolasius, and Lasius pallitarsis, which we confirm to represent a seventh subgenus, the other clade contains Dendrolasius, and Lasius sensu stricto. The subgenus Cautolasius, displaying neither social parasitism nor fungiculture, probably belongs to the second clade, but its phylogenetic position is not resolved at the cutoff values of node support we apply. Possible causes for previous problems with reconstructing the Lasius phylogeny include use of other reconstruction techniques, possibly more prone to instabilities in some instances, and the inclusion of phylogenetically distorting characters. By establishing an updated phylogenetic framework, our study provides the basis for a later formal taxonomic revision of subgenera and for studying the evolution of various ecologically and sociobiologically relevant traits of Lasius, although there is need for future studies to include nuclear genes and additional samples from the Nearctic. Both social parasitism and fungiculture evolved twice in Lasius, once in each major lineage, which opens up new opportunities for comparative analyses. The repeated evolution of social parasitism has been established for other groups of ants, though not for temporary social parasitism as found

  16. Host range and community structure of avian nest parasites in the genus Philornis (Diptera: Muscidae) on the island of Trinidad.

    PubMed

    Bulgarella, Mariana; Heimpel, George E

    2015-09-01

    Parasite host range can be influenced by physiological, behavioral, and ecological factors. Combining data sets on host-parasite associations with phylogenetic information of the hosts and the parasites involved can generate evolutionary hypotheses about the selective forces shaping host range. Here, we analyzed associations between the nest-parasitic flies in the genus Philornis and their host birds on Trinidad. Four of ten Philornis species were only reared from one species of bird. Of the parasite species with more than one host bird species, P. falsificus was the least specific and P. deceptivus the most specific attacking only Passeriformes. Philornis flies in Trinidad thus include both specialists and generalists, with varying degrees of specificity within the generalists. We used three quantities to more formally compare the host range of Philornis flies: the number of bird species attacked by each species of Philornis, a phylogenetically informed host specificity index (Poulin and Mouillot's S TD), and a branch length-based S TD. We then assessed the phylogenetic signal of these measures of host range for 29 bird species. None of these measures showed significant phylogenetic signal, suggesting that clades of Philornis did not differ significantly in their ability to exploit hosts. We also calculated two quantities of parasite species load for the birds - the parasite species richness, and a variant of the S TD index based on nodes rather than on taxonomic levels - and assessed the signal of these measures on the bird phylogeny. We did not find significant phylogenetic signal for the parasite species load or the node-based S TD index. Finally, we calculated the parasite associations for all bird pairs using the Jaccard index and regressed these similarity values against the number of nodes in the phylogeny separating bird pairs. This analysis showed that Philornis on Trinidad tend to feed on closely related bird species more often than expected by chance.

  17. Life cycle and molecular phylogeny of the dinoflagellates Chytriodinium and Dissodinium, ectoparasites of copepod eggs.

    PubMed

    Gómez, Fernando; Moreira, David; López-García, Purificación

    2009-11-01

    The dinoflagellates Chytriodinium affine, C. roseum and Dissodinium pseudolunula are ectoparasites of crustacean eggs. Here, we present new observations regarding their life cycle based on coastal plankton samples and incubations and analyze their molecular phylogeny using the small subunit ribosomal RNA gene (SSU rDNA) as a marker. In contrast to the typical stages already documented for its life cycle, we observed that D. pseudolunula dinospores may exceptionally differentiate inside a globular cyst. Despite its parasitic life style, the cysts and dinospores of D. pseudolunula contain chlorophyll a. We obtained the first SSU rDNA sequences for the genera Chytriodinium (the type C. roseum and C. affine) and Dissodinium (D. pseudolunula). Classical taxonomical schemes have ascribed these genera to the order Blastodiniales. However, our SSU rDNA-based phylogenetic analysis shows that these ectoparasites form a clade in the Gymnodinium sensu stricto group, unarmored dinokaryotic dinoflagellates of the order Gymnodiniales. They branch in a subgroup composed of warnowiids, polykrikoids, the type of Gymnodinium, G. fuscum and G. aureolum. Although Chytriodinium and Dissodinium appear to be relatives based on SSU rDNA phylogeny, feeding and host specificity, their life cycles are substantially different. Based on these data we consider that the type of life cycle is a poor criterion for classification at the family level. We suggest that the morphology of the infective cell is probably the most reliable phenotypic characteristic to determine the systematic position of parasitic dinoflagellates.

  18. 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.

  19. Phylogenetic characterisation of Taenia tapeworms in spotted hyenas and reconsideration of the "Out of Africa" hypothesis of Taenia in humans.

    PubMed

    Terefe, Yitagele; Hailemariam, Zerihun; Menkir, Sissay; Nakao, Minoru; Lavikainen, Antti; Haukisalmi, Voitto; Iwaki, Takashi; Okamoto, Munehiro; Ito, Akira

    2014-07-01

    The African origin of hominins suggests that Taenia spp. in African carnivores are evolutionarily related to the human-infecting tapeworms Taenia solium, Taenia saginata and Taenia asiatica. Nevertheless, the hypothesis has not been verified through molecular phylogenetics of Taenia. This study aimed to perform phylogenetic comparisons between Taenia spp. from African hyenas and the congeneric human parasites. During 2010-2013, 233 adult specimens of Taenia spp. were collected from 11 spotted hyenas in Ethiopia. A screening based on short DNA sequences of the cytochrome c oxidase subunit 1 gene classified the samples into four mitochondrial lineages designated as I-IV. DNA profiles of nuclear genes for DNA polymerase delta (pold) and phosphoenolpyruvate carboxykinase (pepck) showed that lineages II and III can be assigned as two independent species. Common haplotypes of pold and pepck were frequently found in lineages I and IV, suggesting that they constitute a single species. Morphological observations suggested that lineage II is Taenia crocutae, but the other lineages were morphologically inconsistent with known species, suggesting the involvement of two new species. A phylogenetic tree of Taenia spp. was reconstructed by the maximum likelihood method using all protein-coding genes of their mitochondrial genomes. The tree clearly demonstrated that T. crocutae is sister to T. saginata and T. asiatica, whereas T. solium was confirmed to be sister to the brown bear tapeworm, Taenia arctos. The tree also suggested that T. solium and T. arctos are related to two species of Taenia in hyenas, corresponding to lineages I+IV and III. These results may partially support the African origin of human-infecting Taenia spp., but there remains a possibility that host switching of Taenia to hominins was not confined to Africa. Additional taxa from African carnivores are needed for further testing of the "Out of Africa" hypothesis of Taenia in humans. Copyright © 2014 Australian

  20. [An experimental study of the susceptibility of the snakehead Ophiocephalus argus to infestation by larvae of the tapeworm Diphyllobothrium latum].

    PubMed

    Khodakova, V I; Zholdasova, I M; Allaniiazova, T; Frolova, A A; Artamoshin, A S; Guseva, L N; Arystanov, E; Gitsu, G A

    1998-01-01

    Experiments were made to infect young Ophiocephalus argus, the fish of prey delivered from eastern Asia in the Amu-Dar'ya River basin, outside the area of the broad tapeworm Diphyllobothrium latum. The dalags were infected mainly by ingesting the local copepods Arctodiaptomus salinus, the experimentally invaded larvae of the broad tapeworm. The latter larvae were obtained from the development of eggs of the helminth isolated from strobilae from the patients treated in Perm Province. D. latum plerocercoids lived in the dalags nearly 3 weeks, then they died and lysed. Thus, the dalag cannot be a supplementary host of D. latum.

  1. Random sampling of constrained phylogenies: conducting phylogenetic analyses when the phylogeny is partially known.

    PubMed

    Housworth, E A; Martins, E P

    2001-01-01

    Statistical randomization tests in evolutionary biology often require a set of random, computer-generated trees. For example, earlier studies have shown how large numbers of computer-generated trees can be used to conduct phylogenetic comparative analyses even when the phylogeny is uncertain or unknown. These methods were limited, however, in that (in the absence of molecular sequence or other data) they allowed users to assume that no phylogenetic information was available or that all possible trees were known. Intermediate situations where only a taxonomy or other limited phylogenetic information (e.g., polytomies) are available are technically more difficult. The current study describes a procedure for generating random samples of phylogenies while incorporating limited phylogenetic information (e.g., four taxa belong together in a subclade). The procedure can be used to conduct comparative analyses when the phylogeny is only partially resolved or can be used in other randomization tests in which large numbers of possible phylogenies are needed.

  2. The First Molecular Phylogeny of Strepsiptera (Insecta) Reveals an Early Burst of Molecular Evolution Correlated with the Transition to Endoparasitism

    PubMed Central

    McMahon, Dino P.; Hayward, Alexander; Kathirithamby, Jeyaraney

    2011-01-01

    A comprehensive model of evolution requires an understanding of the relationship between selection at the molecular and phenotypic level. We investigate this in Strepsiptera, an order of endoparasitic insects whose evolutionary biology is poorly studied. We present the first molecular phylogeny of Strepsiptera, and use this as a framework to investigate the association between parasitism and molecular evolution. We find evidence of a significant burst in the rate of molecular evolution in the early history of Strepsiptera. The evolution of morphological traits linked to parasitism is significantly correlated with the pattern in molecular rate. The correlated burst in genotypic-phenotypic evolution precedes the main phase of strepsipteran diversification, which is characterised by the return to a low and even molecular rate, and a period of relative morphological stability. These findings suggest that the transition to endoparasitism led to relaxation of selective constraint in the strepsipteran genome. Our results indicate that a parasitic lifestyle can affect the rate of molecular evolution, although other causal life-history traits correlated with parasitism may also play an important role. PMID:21738621

  3. Morphology, epidemiology, and phylogeny of Babesia: An overview

    PubMed Central

    Laha, Ramgopal; Das, M; Sen, A

    2015-01-01

    Babesiosis is a tick-borne hemoprotozoan disease of domestic and wild animals. The disease is caused by various species of Babesia and some species of Babesia have also zoonotic significance. The parasite in vertebrate hosts’ remains in erythrocytes and the morphology of Babesia spp. is not uniform in all vertebrate hosts. With the advancement of science, particularly the use of molecular techniques made it easy to study the evolution of parasites and thereby reclassifying Babesia spp. as per their phylogeny and to establish the relation of one isolate of Babesia spp. with isolates throughout the world. An attempt also made in this communication to enlighten the readers regarding relationship of one isolate of Babesia spp. of a particular area to another isolate of Babesia spp. of that area or other parts of the world and phylogenetic classification of Babesia spp. was also discussed. It has been concluded that as the study on Babesia is complex in nature so monitoring of the infection with the use of modern techniques is very much needed to control the infection. Second, more research work on phylogenetic relationship of Babesia spp. isolated from different hosts is needed, particularly in India to know the evolution of Babesia spp. of a particular area, as it has great importance to study the trans boundary diseases of animals. PMID:26629451

  4. Parasite biodiversity and its determinants in coastal marine teleost fishes of Brazil.

    PubMed

    Luque, J L; Mouillot, D; Poulin, R

    2004-06-01

    Recent studies of the forces behind the diversification of parasite assemblages have shed light on many aspects of parasite biodiversity. By using only parasite species richness as their measure of diversity, however, previous investigations have ignored the relatedness among parasite species and the taxonomic structure of the assemblages, which contain much information about their evolutionary origins. Here, we performed a comparative analysis across 50 species of fish from the coast of Brazil; we evaluated the effects of several host traits (body size, social behaviour, feeding habits, preference for benthic vs. pelagic habitats, depth range, and ability to enter brackish waters) on the diversity of their assemblages of metazoan parasites. As measures of diversity, we used parasite species richness, as well as the average taxonomic distinctness of the assemblage and its variance; the latter measures are based on the average taxonomic distance between any two parasite species in an assemblage. Unlike parasite species richness, taxonomic distinctness was unaffected by the number of host individuals examined per species. Fish body length proved to be the main predictor of parasite species richness, even when controlling for the confounding influences of host phylogeny and sampling effort, although it did not correlate with measures of parasite taxonomic distinctness. Predatory fish also had higher parasite species richness than planktivores, but this trend could not be confirmed using phylogenetically independent contrasts between host taxa. The main host feature associated with the taxonomic diversity of parasites was schooling behaviour, with schooling fish having more taxonomically diverse parasite assemblages than those of their non-schooling relatives. When focusing on endoparasite species only, both predatory feeding habits and a broad depth range were associated with the taxonomic distinctness of parasites. Our results suggest that certain host traits (i

  5. Integrating chytrid fungal parasites into plankton ecology: research gaps and needs.

    PubMed

    Frenken, Thijs; Alacid, Elisabet; Berger, Stella A; Bourne, Elizabeth C; Gerphagnon, Mélanie; Grossart, Hans-Peter; Gsell, Alena S; Ibelings, Bas W; Kagami, Maiko; Küpper, Frithjof C; Letcher, Peter M; Loyau, Adeline; Miki, Takeshi; Nejstgaard, Jens C; Rasconi, Serena; Reñé, Albert; Rohrlack, Thomas; Rojas-Jimenez, Keilor; Schmeller, Dirk S; Scholz, Bettina; Seto, Kensuke; Sime-Ngando, Télesphore; Sukenik, Assaf; Van de Waal, Dedmer B; Van den Wyngaert, Silke; Van Donk, Ellen; Wolinska, Justyna; Wurzbacher, Christian; Agha, Ramsy

    2017-10-01

    Chytridiomycota, often referred to as chytrids, can be virulent parasites with the potential to inflict mass mortalities on hosts, causing e.g. changes in phytoplankton size distributions and succession, and the delay or suppression of bloom events. Molecular environmental surveys have revealed an unexpectedly large diversity of chytrids across a wide range of aquatic ecosystems worldwide. As a result, scientific interest towards fungal parasites of phytoplankton has been gaining momentum in the past few years. Yet, we still know little about the ecology of chytrids, their life cycles, phylogeny, host specificity and range. Information on the contribution of chytrids to trophic interactions, as well as co-evolutionary feedbacks of fungal parasitism on host populations is also limited. This paper synthesizes ideas stressing the multifaceted biological relevance of phytoplankton chytridiomycosis, resulting from discussions among an international team of chytrid researchers. It presents our view on the most pressing research needs for promoting the integration of chytrid fungi into aquatic ecology. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Size matters for lice on birds: Coevolutionary allometry of host and parasite body size.

    PubMed

    Harnos, Andrea; Lang, Zsolt; Petrás, Dóra; Bush, Sarah E; Szabó, Krisztián; Rózsa, Lajos

    2017-02-01

    Body size is one of the most fundamental characteristics of all organisms. It influences physiology, morphology, behavior, and even interspecific interactions such as those between parasites and their hosts. Host body size influences the magnitude and variability of parasite size according to Harrison's rule (HR: positive relationship between host and parasite body sizes) and Poulin's Increasing Variance Hypothesis (PIVH: positive relationship between host body size and the variability of parasite body size). We analyzed parasite-host body size allometry for 581 species of avian lice (∼15% of known diversity) and their hosts. We applied phylogenetic generalized least squares (PGLS) methods to account for phylogenetic nonindependence controlling for host and parasite phylogenies separately and variance heterogeneity. We tested HR and PIVH for the major families of avian lice (Ricinidae, Menoponidae, Philopteridae), and for distinct ecological guilds within Philopteridae. Our data indicate that most families and guilds of avian lice follow both HR and PIVH; however, ricinids did not follow PIVH and the "body lice" guild of philopterid lice did not follow HR or PIVH. We discuss mathematical and ecological factors that may be responsible for these patterns, and we discuss the potential pervasiveness of these relationships among all parasites on Earth. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  7. Selective therapy in equine parasite control--application and limitations.

    PubMed

    Nielsen, M K; Pfister, K; von Samson-Himmelstjerna, G

    2014-05-28

    Since the 1960s equine parasite control has relied heavily on frequent anthelmintic treatments often applied with frequent intervals year-round. However, increasing levels of anthelmintic resistance in cyathostomins and Parascaris equorum are now forcing the equine industry to change to a more surveillance-based treatment approach to facilitate a reduction in treatment intensity. The principle of selective therapy has been implemented with success in small ruminant parasite control, and has also found use in horse populations. Typically, egg counts are performed from all individuals in the population, and those exceeding a predetermined cutoff threshold are treated. Several studies document the applicability of this method in populations of adult horses, where the overall cyathostomin egg shedding can be controlled by only treating about half the horses. However, selective therapy has not been evaluated in foals and young horses, and it remains unknown whether the principle is adequate to also provide control over other important parasites such as tapeworms, ascarids, and large strongyles. One recent study associated selective therapy with increased occurrence of Strongylus vulgaris. Studies are needed to evaluate potential health risks associated with selective therapy, and to assess to which extent development of anthelmintic resistance can be delayed with this approach. The choice of strongyle egg count cutoff value for anthelmintic treatment is currently based more on tradition than science, and a recent publication illustrated that apparently healthy horses with egg counts below 100 eggs per gram (EPG) can harbor cyathostomin burdens in the range of 100,000 luminal worms. It remains unknown whether leaving such horses untreated constitutes a potential threat to equine health. The concept of selective therapy has merit for equine strongyle control, but several questions remain as it has not been fully scientifically evaluated. There is a great need for new and

  8. Culinary delights and travel? A review of zoonotic cestodiases and metacestodiases.

    PubMed

    Ito, Akira; Budke, Christine M

    2014-01-01

    Due to increased globalization, food-borne parasitic infections are becoming more prevalent worldwide, including in countries where these parasites and parasitic diseases had previously been well controlled or eradicated. Improved sanitation, health education, and establishment of appropriate food safety mechanisms can go a long way towards the control of many these infections. However, food-borne parasitic infections are still common diseases in developing countries, especially in rural areas. As many of today's travelers are looking to explore more distant locations and partake in the local cuisine, they may be at greater risk of acquiring a food-borne parasitic infection, including those caused by a number of adult and larval tapeworms. This review discusses fish and meat-borne tapeworms and zoonotic metacestodiases of public health importance to both developing and developed countries, with a focus on infection prevention in travelers. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Parasitic plants have increased rates of molecular evolution across all three genomes

    PubMed Central

    2013-01-01

    plants tend to be smaller than their non-parasitic relatives, which may result in more cell generations per year, thus a higher rate of mutations arising from DNA copy errors per unit time. Demonstration that adoption of a parasitic lifestyle influences the rate of genomic evolution is relevant to attempts to infer molecular phylogenies of parasitic plants and to estimate their evolutionary divergence times using sequence data. PMID:23782527

  10. Parasitic plants have increased rates of molecular evolution across all three genomes.

    PubMed

    Bromham, Lindell; Cowman, Peter F; Lanfear, Robert

    2013-06-19

    their non-parasitic relatives, which may result in more cell generations per year, thus a higher rate of mutations arising from DNA copy errors per unit time. Demonstration that adoption of a parasitic lifestyle influences the rate of genomic evolution is relevant to attempts to infer molecular phylogenies of parasitic plants and to estimate their evolutionary divergence times using sequence data.

  11. A hitchhikers guide to the Galápagos: co-phylogeography of Galápagos mockingbirds and their parasites

    PubMed Central

    2011-01-01

    Background Parasites are evolutionary hitchhikers whose phylogenies often track the evolutionary history of their hosts. Incongruence in the evolutionary history of closely associated lineages can be explained through a variety of possible events including host switching and host independent speciation. However, in recently diverged lineages stochastic population processes, such as retention of ancestral polymorphism or secondary contact, can also explain discordant genealogies, even in fully co-speciating taxa. The relatively simple biogeographic arrangement of the Galápagos archipelago, compared with mainland biomes, provides a framework to identify stochastic and evolutionary informative components of genealogic data in these recently diverged organisms. Results Mitochondrial DNA sequences were obtained for four species of Galápagos mockingbirds and three sympatric species of ectoparasites - two louse and one mite species. These data were complemented with nuclear EF1α sequences in selected samples of parasites and with information from microsatellite loci in the mockingbirds. Mitochondrial sequence data revealed differences in population genetic diversity between all taxa and varying degrees of topological congruence between host and parasite lineages. A very low level of genetic variability and lack of congruence was found in one of the louse parasites, which was excluded from subsequent joint analysis of mitochondrial data. The reconciled multi-species tree obtained from the analysis is congruent with both the nuclear data and the geological history of the islands. Conclusions The gene genealogies of Galápagos mockingbirds and two of their ectoparasites show strong phylogeographic correlations, with instances of incongruence mostly explained by ancestral genetic polymorphism. A third parasite genealogy shows low levels of genetic diversity and little evidence of co-phylogeny with their hosts. These differences can mostly be explained by variation in life

  12. Resolving the infection process reveals striking differences in the contribution of environment, genetics and phylogeny to host-parasite interactions

    PubMed Central

    2011-01-01

    Background Infection processes consist of a sequence of steps, each critical for the interaction between host and parasite. Studies of host-parasite interactions rarely take into account the fact that different steps might be influenced by different factors and might, therefore, make different contributions to shaping coevolution. We designed a new method using the Daphnia magna - Pasteuria ramosa system, one of the rare examples where coevolution has been documented, in order to resolve the steps of the infection and analyse the factors that influence each of them. Results Using the transparent Daphnia hosts and fluorescently-labelled spores of the bacterium P. ramosa, we identified a sequence of infection steps: encounter between parasite and host; activation of parasite dormant spores; attachment of spores to the host; and parasite proliferation inside the host. The chances of encounter had been shown to depend on host genotype and environment. We tested the role of genetic and environmental factors in the newly described activation and attachment steps. Hosts of different genotypes, gender and species were all able to activate endospores of all parasite clones tested in different environments; suggesting that the activation cue is phylogenetically conserved. We next established that parasite attachment occurs onto the host oesophagus independently of host species, gender and environmental conditions. In contrast to spore activation, attachment depended strongly on the combination of host and parasite genotypes. Conclusions Our results show that different steps are influenced by different factors. Host-type-independent spore activation suggests that this step can be ruled out as a major factor in Daphnia-Pasteuria coevolution. On the other hand, we show that the attachment step is crucial for the pronounced genetic specificities of this system. We suggest that this one step can explain host population structure and could be a key force behind coevolutionary

  13. Resolving the infection process reveals striking differences in the contribution of environment, genetics and phylogeny to host-parasite interactions.

    PubMed

    Duneau, David; Luijckx, Pepijn; Ben-Ami, Frida; Laforsch, Christian; Ebert, Dieter

    2011-02-22

    Infection processes consist of a sequence of steps, each critical for the interaction between host and parasite. Studies of host-parasite interactions rarely take into account the fact that different steps might be influenced by different factors and might, therefore, make different contributions to shaping coevolution. We designed a new method using the Daphnia magna - Pasteuria ramosa system, one of the rare examples where coevolution has been documented, in order to resolve the steps of the infection and analyse the factors that influence each of them. Using the transparent Daphnia hosts and fluorescently-labelled spores of the bacterium P. ramosa, we identified a sequence of infection steps: encounter between parasite and host; activation of parasite dormant spores; attachment of spores to the host; and parasite proliferation inside the host. The chances of encounter had been shown to depend on host genotype and environment. We tested the role of genetic and environmental factors in the newly described activation and attachment steps. Hosts of different genotypes, gender and species were all able to activate endospores of all parasite clones tested in different environments; suggesting that the activation cue is phylogenetically conserved. We next established that parasite attachment occurs onto the host oesophagus independently of host species, gender and environmental conditions. In contrast to spore activation, attachment depended strongly on the combination of host and parasite genotypes. Our results show that different steps are influenced by different factors. Host-type-independent spore activation suggests that this step can be ruled out as a major factor in Daphnia-Pasteuria coevolution. On the other hand, we show that the attachment step is crucial for the pronounced genetic specificities of this system. We suggest that this one step can explain host population structure and could be a key force behind coevolutionary cycles. We discuss how different

  14. 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.

  15. 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.

  16. Validity of the bear tapeworm Diphyllobothrium ursi (Cestoda: Diphyllobothriidae) based on morphological and molecular markers.

    PubMed

    Yamasaki, Hiroshi; Muto, Maki; Yamada, Minoru; Arizono, Naoki; Rausch, Robert L

    2012-12-01

    The bear tapeworm Diphyllobothrium ursi is described based upon the morphology of adult tapeworms recovered from the brown bear (Ursus arctos middendorffi) and larval plerocercoids found in sockeye salmon (Oncorhynchus nerka) from Kodiak Island in Alaska in 1952. However, in 1987 D. ursi was synonymized with Diphyllobothrium dendriticum, and the taxonomic relationship between both species has not subsequently been revised. In this study mitochondrial cytochrome c oxidase subunit 1 gene (cox1) sequences of holotype and paratype D. ursi specimens that had been preserved in a formalin-acetic acid-alcohol solution since the time the species was initially described approximately 60 yr ago were analyzed. Molecular and phylogenetic analysis of the cox1 sequences revealed that D. ursi is more closely related to D. dendriticum than it is to Diphyllobothrium nihonkaiense and Diphyllobothrium latum. In addition to molecular evidence, differences in the life cycle and ecology of the larval plerocercoids between D. ursi and D. dendriticum also suggest that D. ursi is a distinct species, separate from D. dendriticum and D. nihonkaiense, and also possibly from D. latum .

  17. Baculovirus phylogeny and evolution.

    PubMed

    Herniou, Elisabeth A; Jehle, Johannes A

    2007-10-01

    The family Baculoviridae represents one of the largest and most diverse groups of viruses and a unique model for studying the forces driving the evolution and biodiversity of double-stranded DNA viruses with large genomes. With the advent of comparative genomics, the phylogenetic relationships of baculoviruses have been put on solid bases. This, as well as improved bioinformatic approaches, has provided a detailed picture of baculovirus phylogeny and evolution. According to the present knowledge, baculoviruses can be classified into at least four evolutionary lineages: the most ancestral dipteran nucleopolyhedroviruses, the hymenopteran nucleopolyhedroviruses and the lepidopteran nucleopolyhedroviruses and granuloviruses. Despite the growing understanding of baculovirus phylogeny and macro-evolution, our knowledge of the micro-evolutionary processes within baculovirus species and virus populations is still limited. Here we present the state of the art on baculovirus phylogeny and evolution.

  18. Hidden biodiversity in an ancient lake: phylogenetic congruence between Lake Tanganyika tropheine cichlids and their monogenean flatworm parasites.

    PubMed

    Vanhove, Maarten P M; Pariselle, Antoine; Van Steenberge, Maarten; Raeymaekers, Joost A M; Hablützel, Pascal I; Gillardin, Céline; Hellemans, Bart; Breman, Floris C; Koblmüller, Stephan; Sturmbauer, Christian; Snoeks, Jos; Volckaert, Filip A M; Huyse, Tine

    2015-09-03

    The stunning diversity of cichlid fishes has greatly enhanced our understanding of speciation and radiation. Little is known about the evolution of cichlid parasites. Parasites are abundant components of biodiversity, whose diversity typically exceeds that of their hosts. In the first comprehensive phylogenetic parasitological analysis of a vertebrate radiation, we study monogenean parasites infecting tropheine cichlids from Lake Tanganyika. Monogeneans are flatworms usually infecting the body surface and gills of fishes. In contrast to many other parasites, they depend only on a single host species to complete their lifecycle. Our spatially comprehensive combined nuclear-mitochondrial DNA dataset of the parasites covering almost all tropheine host species (N = 18), reveals species-rich parasite assemblages and shows consistent host-specificity. Statistical comparisons of host and parasite phylogenies based on distance and topology-based tests demonstrate significant congruence and suggest that host-switching is rare. Molecular rate evaluation indicates that species of Cichlidogyrus probably diverged synchronically with the initial radiation of the tropheines. They further diversified through within-host speciation into an overlooked species radiation. The unique life history and specialisation of certain parasite groups has profound evolutionary consequences. Hence, evolutionary parasitology adds a new dimension to the study of biodiversity hotspots like Lake Tanganyika.

  19. Endoparasite fauna of five Gadiformes fish species from the coast of Chile: host ecology versus phylogeny.

    PubMed

    Chávez, R A; González, M T; Oliva, M E; Valdivia, I M

    2012-03-01

    The aims of the present study were to compare, using multivariate analyses, the degree of similarity of the endoparasite fauna of five fish species belonging to the order Gadiformes: Merluccius gayi, Merluccius australis, Macruronus magellanicus (Gadoidei) and Micromesistius australis and Nezumia pulchella (Macrouroidei), from the southern and central Chilean coast, and to evaluate whether the composition of the endoparasite fauna was determined by phylogenetic or ecological relationships. We employed our database of Merluccius australis, M. magellanicus and Micromesistius australis, which was complemented with published information for M. magellanicus, Merluccius australis, Micromesistius australis, M. gayi and N. pulchella. A higher number of endoparasite species was recorded for Merluccius australis, Micromesistius australis and M. magellanicus, namely Anisakis sp. and Hepatoxylon trichiuri, which is the most prevalent parasite among these hosts. Aporocotyle wilhelmi and Hysterothylacium sp. were detected only in M. gayi, whereas Lepidapedon sp. was found exclusively in N. pulchella. These results suggest that fish ecology rather than host phylogeny was the most important factor for the determination of similarity in parasite composition. This result could be explained by the similar trophic patterns of hosts and by the predominance of generalist larval species among these fish parasite communities.

  20. Geographic Correlation between Tapeworm Carriers and Heavily Infected Cysticercotic Pigs

    PubMed Central

    O'Neal, Seth E.; Moyano, Luz M.; Ayvar, Viterbo; Gonzalvez, Guillermo; Diaz, Andre; Rodriguez, Silvia; Wilkins, Patricia P.; Tsang, Victor C. W.; Gilman, Robert H.; Garcia, Hector H.; Gonzalez, Armando E.

    2012-01-01

    Background Neurocysticercosis is a leading cause of preventable epilepsy in the developing world. Sustainable community-based interventions are urgently needed to control transmission of the causative parasite, Taenia solium. We examined the geospatial relationship between live pigs with visible cysticercotic cysts on their tongues and humans with adult intestinal tapeworm infection (taeniasis) in a rural village in northern Peru. The objective was to determine whether tongue-positive pigs could indicate high-risk geographic foci for taeniasis to guide targeted screening efforts. This approach could offer significant benefit compared to mass intervention. Methods We recorded geographic coordinates of all village houses, collected stool samples from all consenting villagers, and collected blood and examined tongues of all village pigs. Stool samples were processed by enzyme-linked immunosorbent assay (ELISA) for presence of Taenia sp. coproantigens indicative of active taeniasis; serum was processed by enzyme-linked immunoelectrotransfer blot for antibodies against T. solium cysticercosis (EITB LLGP) and T. solium taeniasis (EITB rES33). Findings Of 548 pigs, 256 (46.7%) were positive for antibodies against cysticercosis on EITB LLGP. Of 402 fecal samples, 6 (1.5%) were positive for the presence of Taenia sp. coproantigens. The proportion of coproantigen-positive individuals differed significantly between residents living within 100-meters of a tongue-positive pig (4/79, 5.1%) and residents living >100 meters from a tongue-positive pig (2/323, 0.6%) (p = 0.02). The prevalence of taeniasis was >8 times higher among residents living within 100 meters of a tongue-positive pig compared to residents living outside this range (adjusted PR 8.1, 95% CI 1.4–47.0). Conclusions Tongue-positive pigs in endemic communities can indicate geospatial foci in which the risk for taeniasis is increased. Targeted screening or presumptive treatment for taeniasis within these high

  1. Principal intestinal parasites of dogs in Tirana, Albania.

    PubMed

    Xhaxhiu, Dashamir; Kusi, Ilir; Rapti, Dhimitër; Kondi, Elisabeta; Postoli, Rezart; Rinaldi, Laura; Dimitrova, Zlatka M; Visser, Martin; Knaus, Martin; Rehbein, Steffen

    2011-02-01

    From 2004 to 2009, the digestive tracts of 111 dogs from suburban areas around Tirana, Albania, were examined for intestinal helminths. In addition, rectal faecal samples of all dogs were examined for protozoan infections and 48 faecal samples from dogs >6 months of age were processed with the Baermann technique to test for the excretion of lungworm larvae. The heart and pulmonary arteries of 30 dogs >6 months of age also were examined for nematode parasites. The intestinal parasite fauna of the dogs included three protozoan species (Cystoisospora canis, Cystoisospora ohioensis/burrowsi, Sarcocystis spp.), three cestode species (Dipylidium caninum, Taenia hydatigena, Echinococcus granulosus), five nematode species (Ancylostoma caninum, Uncinaria stenocephala, Toxocara canis, Toxascaris leonina, Trichuris vulpis) and one acanthocephalan (Centrorhynchus buteonis). Rates of infection were: 15.3% for C. canis, 31.5% for C. ohioensis/burrowsi, 1.8% for Sarcocystis spp., 65.8% for D. caninum, 16.2% for T. hydatigena, 2.7% for E. granulosus (genotype G1), 13.5% for A. caninum, 64.9% for U. stenocephala, 75.7% for T. canis, 0.9% for T. leonina, 21.6% for T. vulpis and 0.9% for C. buteonis. Up to six species of gastrointestinal parasites were found per dog. The 63 ≤ 6-month-old dogs harboured significantly (p<0.001) fewer gastrointestinal parasite species concurrently (mean 2.65 ± 1.25 species per animal) than the 48 older animals (mean 3.77 ± 1.45 species per animal). Dogs >6 months of age harboured significantly (p<0.05) more D. caninum, T. hydatigena, A. caninum, U. stenocephala and T. vulpis compared to younger dogs. Conversely, the younger dogs harboured significantly (p<0.001) more T. canis than the older ones. There was no difference in the male and female dogs' counts of individual intestinal helminth species apart from T. hydatigena in dogs >6 months of age: Male dogs harboured significantly (p<0.05) more tapeworms than female dogs. Based on faecal examination

  2. Spathebothriidea: survey of species, scolex and egg morphology, and interrelationships of a non-segmented, relictual tapeworm group (Platyhelminthes: Cestoda).

    PubMed

    Kuchta, Roman; Pearson, Rebecca; Scholz, Tomás; Ditrich, Oleg; Olson, Peter D

    2014-08-01

    Tapeworms of the order Spathebothriidea Wardle et McLeod, 1952 (Cestoda) are reviewed. Molecular data made it possible to assess, for the first time, the phylogenetic relationships of all genera and to confirm the validity of Bothrimonus Duvernoy, 1842, Diplocotyle Krabbe, 1874 and Didymobothrium Nybelin, 1922. A survey of all species considered to be valid is provided together with new data on egg and scolex morphology and surface ultrastructure (i.e. microtriches). The peculiar morphology of the members of this group, which is today represented by five effectively monotypic genera whose host associations and geographical distribution show little commonality, indicate that it is a relictual group that was once diverse and widespread. The order potentially represents the earliest branch of true tapeworms (i.e. Eucestoda) among extant forms.

  3. Taenia solium: current understanding of laboratory animal models of taeniosis.

    PubMed

    Flisser, A; Avila, G; Maravilla, P; Mendlovic, F; León-Cabrera, S; Cruz-Rivera, M; Garza, A; Gómez, B; Aguilar, L; Terán, N; Velasco, S; Benítez, M; Jimenez-Gonzalez, D E

    2010-03-01

    Neurocysticercosis is a public health problem in many developing countries and is the most frequent parasitic disease of the brain. The human tapeworm carrier is the main risk factor for acquiring neurocysticercosis. Since the parasite lodges only in the human intestine, experimental models of Taenia solium taeniosis have been explored. Macaques, pigs, dogs, cats and rabbits are unsuccessful hosts even in immunodepressed status. By contrast, rodents are adequate hosts since tapeworms with mature, pregravid and, in some cases, gravid proglottids develop after infection. In this review, information that has been generated with experimental models of taeniosis due to T. solium is discussed. Initially, the use of the model for immunodiagnosis of human taeniosis and evaluation of intervention measures is summarized. Next, descriptions of tapeworms and comparison of hamsters, gerbils and other mammals as experimental models are discussed, as well as data on the humoral immune response, the inflammatory reaction and the production of cytokines associated to Th1 and Th2 responses in the intestinal mucosa. Finally, evaluation of protection induced against the development of tapeworms by recombinant T. solium calreticulin in hamsters is summarized and compared to other studies.

  4. Neurocysticercosis in the infant of a pregnant mother with a tapeworm.

    PubMed

    Asnis, Deborah; Kazakov, Jordan; Toronjadze, Tamar; Bern, Caryn; Garcia, Hector H; McAuliffe, Isabel; Bishop, Henry; Lee, Lillian; Grossmann, Rami; Garcia, Minerva A; Di John, David

    2009-09-01

    Taeniasis occurs after ingestion of undercooked pork infected with cysticerci. Most Taenia solium infections are mild; proglottids are rarely noticed in the feces. Cysticercosis develops with ingestion of eggs from a tapeworm carrier. Cysticercosis affects approximately 50 million people worldwide, and is seen mostly in Central and South America, sub-Saharan Africa, India, and Asia. We present a case of an 18-month-old child living in New York, who presented with seizures caused by neurocysticercosis. A family study found a 22-year-old mother, 7 months pregnant, positive for T. solium, which presented a management dilemma.

  5. Molecular analyses reveal two geographic and genetic lineages for tapeworms, Taenia solium and Taenia saginata, from Ecuador using mitochondrial DNA.

    PubMed

    Solano, Danilo; Navarro, Juan Carlos; León-Reyes, Antonio; Benítez-Ortiz, Washington; Rodríguez-Hidalgo, Richar

    2016-12-01

    Tapeworms Taenia solium and Taenia saginata are the causative agents of taeniasis/cysticercosis. These are diseases with high medical and veterinary importance due to their impact on public health and rural economy in tropical countries. The re-emergence of T. solium as a result of human migration, the economic burden affecting livestock industry, and the large variability of symptoms in several human cysticercosis, encourage studies on genetic diversity, and the identification of these parasites with molecular phylogenetic tools. Samples collected from the Ecuadorian provinces: Loja, Guayas, Manabí, Tungurahua (South), and Imbabura, Pichincha (North) from 2000 to 2012 were performed under Maximum Parsimony analyses and haplotype networks using partial sequences of mitochondrial DNA, cytochrome oxidase subunit I (COI) and NADH subunit I (NDI), from Genbank and own sequences of Taenia solium and Taenia saginata from Ecuador. Both species have shown reciprocal monophyly, which confirms its molecular taxonomic identity. The COI and NDI genes results suggest phylogenetic structure for both parasite species from south and north of Ecuador. In T. solium, both genes gene revealed greater geographic structure, whereas in T. saginata, the variability for both genes was low. In conclusion, COI haplotype networks of T. solium suggest two geographical events in the introduction of this species in Ecuador (African and Asian lineages) and occurring sympatric, probably through the most common routes of maritime trade between the XV-XIX centuries. Moreover, the evidence of two NDI geographical lineages in T. solium from the north (province of Imbabura) and the south (province of Loja) of Ecuador derivate from a common Indian ancestor open new approaches for studies on genetic populations and eco-epidemiology. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. 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

  7. Bipteria vetusta n. sp. – an old parasite in an old host: tracing the origin of myxosporean parasitism in vertebrates.

    PubMed

    Kodádková, Alena; Bartošová-Sojková, Pavla; Holzer, Astrid S; Fiala, Ivan

    2015-03-01

    Myxosporea (Myxozoa), a group of parasitic Cnidaria, use mostly bony fishes (Teleostei) as intermediate hosts; however, they can also parasitize other vertebrates such as cartilaginous fish (Chondrichthyes). Molecular data of myxosporeans from sharks and rays (Elasmobranchii) revealed these parasites to be one of the most basal representatives in the myxosporean phylogenetic tree, suggesting their ancient evolutionary history. A new myxosporean species, Bipteria vetusta n. sp., was found in the gall bladder of rabbit fish, Chimaera monstrosa (Holocephali; Chondrichthyes), and ssrDNA-based phylogeny revealed its basal position within the marine myxosporean lineage. Molecular dating based on ssrDNA analysis suggested the origin of a stem lineage leading to the marine myxosporean lineage at the time of the origin of Chondrichthyes in the Silurian era. The two common lineages of Myxozoa, Myxosporea and Malacosporea, were estimated to have split from their common ancestor in the Cambrian era. Tracing the history of evolution of the "vertebrate host type" character in the context of molecular dating showed that cartilaginous fish represented an ancestral state for all myxosporeans. Teleosts were very likely subsequently parasitized by myxozoans four times, independently. Myxosporean radiation and diversification appear to correlate with intermediate host evolution. The first intermediate hosts of myxosporeans were cartilaginous fish. When bony fish evolved and radiated, myxosporeans switched and adapted to bony fish, and subsequently greatly diversified in this new host niche. We believe that the present study is the first attempt at molecular dating of myxozoan evolution based on an old myxosporean species – a living myxosporean fossil. Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  8. 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."

  9. 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

  10. Development of microsatellite markers in Caryophyllaeus laticeps (Cestoda: Caryophyllidea), monozoic fish tapeworm, using next-generation sequencing approach.

    PubMed

    Králová-Hromadová, Ivica; Minárik, Gabriel; Bazsalovicsová, Eva; Mikulíček, Peter; Oravcová, Alexandra; Pálková, Lenka; Hanzelová, Vladimíra

    2015-02-01

    Caryophyllaeus laticeps (Pallas 1781) (Cestoda: Caryophyllidea) is a monozoic tapeworm of cyprinid fishes with a distribution area that includes Europe, most of the Palaearctic Asia and northern Africa. Broad geographic distribution, wide range of definitive fish hosts and recently revealed high morphological plasticity of the parasite, which is not in an agreement with molecular findings, make this species to be an interesting model for population biology studies. Microsatellites (short tandem repeat (STR) markers), as predominant markers for population genetics, were designed for C. laticeps using a next-generation sequencing (NGS) approach. Out of 165 marker candidates, 61 yielded PCR products of the expected size and in 25 of the candidates a declared repetitive motif was confirmed by Sanger sequencing. After the fragment analysis, six loci were proved to be polymorphic and tested for heterozygosity, Hardy-Weinberg equilibrium and the presence of null alleles on 59 individuals coming from three geographically widely separated populations (Slovakia, Russia and UK). The number of alleles in particular loci and populations ranged from two to five. Significant deficit of heterozygotes and the presence of null alleles were found in one locus in all three populations. Other loci showed deviations from Hardy-Weinberg equilibrium and the presence of null alleles only in some populations. In spite of relatively low polymorphism and the potential presence of null alleles, newly developed microsatellites may be applied as suitable markers in population genetic studies of C. laticeps.

  11. Hox genes and the parasitic flatworms: new opportunities, challenges and lessons from the free-living.

    PubMed

    Olson, P D

    2008-03-01

    Research into the roles played by Hox and related homeotic gene families in the diverse and complex developmental programmes exhibited by parasitic flatworms (Platyhelminthes) can hardly be said to have begun, and thus presents considerable opportunity for new research. Although featured in some of the earliest screens for homeotic genes outside Drosophila and mice, surveys in parasitic flatworms are few in number and almost nothing is yet known of where or when the genes are expressed during ontogeny. This contrasts sharply with a significant body of literature concerning Hox genes in free-living flatworms which have long served as models for the study of regeneration and the maintenance of omnipotent cell lines. Nevertheless, available information suggests that the complement of Hox genes and other classes of homeobox-containing genes in parasitic flatworms is typical of their free-living cousins and of other members of the Lophotrochozoa. Recent work on Schistosoma combined with information on Hox gene expression in planarians indicates that at least some disruption of the clustered genomic arrangement of the genes, as well as of the strict spatial and temporal colinear patterns of expression typical in other groups, may be characteristic of flatworms. However, available data on the genomic arrangement and expression of flatworm Hox genes is so limited at present that such generalities are highly tenuous. Moreover, a basic underlying pattern of colinearity is still observed in their spatial expression patterns making them suitable as cell or region-specific markers. I discuss a number of fundamental developmental questions and some of the challenges to addressing them in relation to each of the major parasitic lineages. In addition, I present newly characterized Hox genes from the model tapeworm Hymenolepis and analyze these by Bayesian inference together with >100 Hox and ParaHox homeodomains of flatworms and select lophotrochozoan taxa, providing a

  12. Molecular phylogeny and systematics of the Echinostomatoidea Looss, 1899 (Platyhelminthes: Digenea).

    PubMed

    Tkach, Vasyl V; Kudlai, Olena; Kostadinova, Aneta

    2016-03-01

    The Echinostomatoidea is a large, cosmopolitan group of digeneans currently including nine families and 105 genera, the vast majority parasitic, as adults, in birds with relatively few taxa parasitising mammals, reptiles and, exceptionally, fish. Despite the complex structure, diverse content and substantial species richness of the group, almost no attempt has been made to elucidate its phylogenetic relationships at the suprageneric level based on molecules due to the lack of data. Herein, we evaluate the consistency of the present morphology-based classification system of the Echinostomatoidea with the phylogenetic relationships of its members based on partial sequences of the nuclear lsrRNA gene for a broad diversity of taxa (80 species, representing eight families and 40 genera), including representatives of five subfamilies of the Echinostomatidae, which currently exhibits the most complex taxonomic structure within the superfamily. This first comprehensive phylogeny for the Echinostomatoidea challenged the current systematic framework based on comparative morphology. A morphology-based evaluation of this new molecular framework resulted in a number of systematic and nomenclatural changes consistent with the phylogenetic estimates of the generic and suprageneric boundaries and a new phylogeny-based classification of the Echinostomatoidea. In the current systematic treatment: (i) the rank of two family level lineages, the former Himasthlinae and Echinochasminae, is elevated to full family status; (ii) Caballerotrema is distinguished at the family level; (iii) the content and diagnosis of the Echinostomatidae (sensu stricto) (s. str.) are revised to reflect its phylogeny, resulting in the abolition of the Nephrostominae and Chaunocephalinae as synonyms of the Echinostomatidae (s. str.); (iv) Artyfechinostomum, Cathaemasia, Rhopalias and Ribeiroia are re-allocated within the Echinostomatidae (s. str.), resulting in the abolition of the Cathaemasiidae, Rhopaliidae

  13. Intestinal Parasitic Infections and Environmental Water Contamination in a Rural Village of Northern Lao PDR.

    PubMed

    Ribas, Alexis; Jollivet, Chloé; Morand, Serge; Thongmalayvong, Boupha; Somphavong, Silaphet; Siew, Chern-Chiang; Ting, Pei-Jun; Suputtamongkol, Saipin; Saensombath, Viengsaene; Sanguankiat, Surapol; Tan, Boon-Huan; Paboriboune, Phimpha; Akkhavong, Kongsap; Chaisiri, Kittipong

    2017-10-01

    A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.

  14. Intestinal Parasitic Infections and Environmental Water Contamination in a Rural Village of Northern Lao PDR

    PubMed Central

    Ribas, Alexis; Jollivet, Chloé; Morand, Serge; Thongmalayvong, Boupha; Somphavong, Silaphet; Siew, Chern-Chiang; Ting, Pei-Jun; Suputtamongkol, Saipin; Saensombath, Viengsaene; Sanguankiat, Surapol; Tan, Boon-Huan; Paboriboune, Phimpha; Akkhavong, Kongsap; Chaisiri, Kittipong

    2017-01-01

    A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor. PMID:29103267

  15. Getting there and around: Host range oscillations during colonization of the Canary Islands by the parasitic nematode Spauligodon.

    PubMed

    Jorge, Fátima; Perera, Ana; Poulin, Robert; Roca, Vicente; Carretero, Miguel A

    2018-01-01

    Episodes of expansion and isolation in geographic range over space and time, during which parasites have the opportunity to expand their host range, are linked to the development of host-parasite mosaic assemblages and parasite diversification. In this study, we investigated whether island colonization events lead to host range oscillations in a taxon of host-specific parasitic nematodes of the genus Spauligodon in the Canary Islands. We further investigated whether range oscillations also resulted in shifts in host breadth (i.e., specialization), as expected for parasites on islands. Parasite phylogeny and divergence time estimates were inferred from molecular data with Bayesian methods. Host divergence times were set as calibration priors after a priori evaluation with a global-fit method of which individual host-parasite associations likely represent cospeciation links. Parasite colonization history was reconstructed, followed by an estimation of oscillation events and specificity level. The results indicate the presence of four Spauligodon clades in the Canary Islands, which originated from at least three different colonization events. We found evidence of host range oscillations to truly novel hosts, which in one case led to higher diversification. Contemporary host-parasite associations show strong host specificity, suggesting that changes in host breadth were limited to the shift period. Lineages with more frequent and wider taxonomic host range oscillations prior to the initial colonization event showed wider range oscillations during colonization and diversification within the archipelago. Our results suggest that a lineage's evolutionary past may be the best indicator of a parasite's potential for future range expansions. © 2017 John Wiley & Sons Ltd.

  16. Simultaneous phylogeny reconstruction and multiple sequence alignment

    PubMed Central

    Yue, Feng; Shi, Jian; Tang, Jijun

    2009-01-01

    Background A phylogeny is the evolutionary history of a group of organisms. To date, sequence data is still the most used data type for phylogenetic reconstruction. Before any sequences can be used for phylogeny reconstruction, they must be aligned, and the quality of the multiple sequence alignment has been shown to affect the quality of the inferred phylogeny. At the same time, all the current multiple sequence alignment programs use a guide tree to produce the alignment and experiments showed that good guide trees can significantly improve the multiple alignment quality. Results We devise a new algorithm to simultaneously align multiple sequences and search for the phylogenetic tree that leads to the best alignment. We also implemented the algorithm as a C program package, which can handle both DNA and protein data and can take simple cost model as well as complex substitution matrices, such as PAM250 or BLOSUM62. The performance of the new method are compared with those from other popular multiple sequence alignment tools, including the widely used programs such as ClustalW and T-Coffee. Experimental results suggest that this method has good performance in terms of both phylogeny accuracy and alignment quality. Conclusion We present an algorithm to align multiple sequences and reconstruct the phylogenies that minimize the alignment score, which is based on an efficient algorithm to solve the median problems for three sequences. Our extensive experiments suggest that this method is very promising and can produce high quality phylogenies and alignments. PMID:19208110

  17. Role of porcine serum haptoglobin in the host-parasite relationship of Taenia solium cysticercosis.

    PubMed

    Navarrete-Perea, José; Toledano-Magaña, Yanis; De la Torre, Patricia; Sciutto, Edda; Bobes, Raúl José; Soberón, Xavier; Laclette, Juan Pedro

    2016-06-01

    Human and porcine cysticercosis is a parasitic disease caused by the larval stage (cysts) of the tapeworm Taenia solium. Cysts may live in several host tissues such as skeletal muscle or brain. We have previously described the presence of host haptoglobin (Hp) and hemoglobin (Hb) in different protein extracts of the T. solium cysts. Here, we report the binding of host Hp and Hb to a number of cyst proteins, evaluated through measuring electrophoretic and light absorbance changes. In the sera obtained from 18 cysticercotic pigs, Hp-Hb complexes were abundant, whereas free Hp was undetectable. In contrast, in the sera from non 18 cysticercotic pigs, Hp-Hb and free Hp were found. In the soluble protein fraction of cysts tissue, free Hp was detected showing a considerable Hb-binding ability, whereas in the vesicular fluid, Hp is mainly bound to Hb. Interestingly, assays carried out with the insoluble fraction of T. solium cysts tissue, showed binding of Hp and Hp-Hb in a saturable way, suggesting the existence of specific interactions. Our results suggested that the parasite can take advantage of the uptaken host Hp and Hb, either free or in complexes, as a source of iron or as a way to modulate the inflammatory response surrounding the T. solium cysts. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Echinococcus granulosus in gray wolves and ungulates in Idaho and Montana, USA.

    PubMed

    Foreyt, William J; Drew, Mark L; Atkinson, Mark; McCauley, Deborah

    2009-10-01

    We evaluated the small intestines of 123 gray wolves (Canis lupus) that were collected from Idaho, USA (n=63), and Montana, USA (n=60), between 2006 and 2008 for the tapeworm Echinococcus granulosus. The tapeworm was detected in 39 of 63 wolves (62%) in Idaho, USA, and 38 of 60 wolves (63%) in Montana, USA. The detection of thousands of tapeworms per wolf was a common finding. In Idaho, USA, hydatid cysts, the intermediate form of E. granulosus, were detected in elk (Cervus elaphus), mule deer (Odocoileus hemionus), and a mountain goat (Oreamnos americanus). In Montana, USA, hydatid cysts were detected in elk. To our knowledge, this is the first report of adult E. granulosus in Idaho, USA, or Montana, USA. It is unknown whether the parasite was introduced into Idaho, USA, and southwestern Montana, USA, with the importation of wolves from Alberta, Canada, or British Columbia, Canada, into Yellowstone National Park, Wyoming, USA, and central Idaho, USA, in 1995 and 1996, or whether the parasite has always been present in other carnivore hosts, and wolves became a new definitive host. Based on our results, the parasite is now well established in wolves in these states and is documented in elk, mule deer, and a mountain goat as intermediate hosts.

  19. The evolution of virulence in primate malaria parasites based on Bayesian reconstructions of ancestral states.

    PubMed

    Garamszegi, László Zsolt

    2011-02-01

    Plasmodium parasites, the causative agents of malaria, are generally considered as harmful parasites, but many of them cause mild symptoms. Little is known about the evolutionary history and phylogenetic constraints that generate this interspecific variation in virulence due to uncertainties about the phylogenetic associations of parasites. Here, to account for such phylogenetic uncertainty, phylogenetic methods based on Bayesian statistics were followed in combination with sequence data from five genes to estimate the ancestral state of virulence in primate Plasmodium parasites. When recent parasites were categorised according to the damage caused to the host, Bayesian estimates of ancestral states indicated that the acquisition of a harmful host exploitation strategy is more likely to be a recent evolutionary event than a result of an ancient change in a character state altering virulence. On the contrary, there was more evidence for moderate host exploitation having a deep origin along the phylogenetic tree. Moreover, the evolution of host severity is determined by the phylogenetic relationships of parasites, as severity gains did not appear randomly on the evolutionary tree. Such phylogenetic constraints can be mediated by the acquisition of virulence genes. As the impact of a parasite on a host is the result of both the parasite's investment in reproduction and host sensitivity, virulence was also estimated by calculating peak parasitemia after eliminating host effects. A directional random-walk evolutionary model showed that the ancestral primate malarias reproduced at very low parasitemia in their hosts. Consequently, the extreme variation in the outcome of malaria infection in different host species can be better understood in light of the phylogeny of parasites. Copyright © 2010 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  20. Helminth (Cestoda, Nematoda) and coccidian (Apicomplexa: Eimeriidae) parasites of the eastern small-footed myotis, Myotis leibii (Chiroptera: Vespertilionidae) from Arkansas, with a description of a new species of Eimeria.

    PubMed

    McAllister, Chris T; Seville, R Scott; Bursey, Charles R

    2017-06-01

    During May and July 2016, 32 eastern small-footed myotis (Myotis leibii) were collected from five counties of northwestern Arkansas and their faeces examined for coccidian parasites. Four of 32 (13%) M. leibii harboured an eimerian that we describe here as new. Oocysts of Eimeria sassei sp. n. were ovoidal to ellipsoidal with a bi-layered wall and measured (length × width, L × W) 18.3 × 15.2 µm, with an L/W ratio of 1.2. A micropyle and oocyst residuum were absent but 1-2 polar granules were present. Sporocysts were ovoidal, 9.6 × 6.3 µm, with an L/W ratio of 1.5. A pronounced, button-like Stieda body was present but substieda and parastieda bodies were absent. A sporocyst residuum was present as distinct aligned or dispersed granules. One bat that we found dead was examined for helminth parasites. It harbored the tapeworm, Vampirolepis sp. and a nematode, Seuratum cancellatum. This is the first coccidian as well as the second helminths reported from M. leibii. In addition, this is the seventh species of coccidian parasite documented from Arkansas bats.

  1. The Schistosoma mansoni phylome: using evolutionary genomics to gain insight into a parasite's biology.

    PubMed

    Silva, Larissa Lopes; Marcet-Houben, Marina; Nahum, Laila Alves; Zerlotini, Adhemar; Gabaldón, Toni; Oliveira, Guilherme

    2012-11-13

    Schistosoma mansoni is one of the causative agents of schistosomiasis, a neglected tropical disease that affects about 237 million people worldwide. Despite recent efforts, we still lack a general understanding of the relevant host-parasite interactions, and the possible treatments are limited by the emergence of resistant strains and the absence of a vaccine. The S. mansoni genome was completely sequenced and still under continuous annotation. Nevertheless, more than 45% of the encoded proteins remain without experimental characterization or even functional prediction. To improve our knowledge regarding the biology of this parasite, we conducted a proteome-wide evolutionary analysis to provide a broad view of the S. mansoni's proteome evolution and to improve its functional annotation. Using a phylogenomic approach, we reconstructed the S. mansoni phylome, which comprises the evolutionary histories of all parasite proteins and their homologs across 12 other organisms. The analysis of a total of 7,964 phylogenies allowed a deeper understanding of genomic complexity and evolutionary adaptations to a parasitic lifestyle. In particular, the identification of lineage-specific gene duplications pointed to the diversification of several protein families that are relevant for host-parasite interaction, including proteases, tetraspanins, fucosyltransferases, venom allergen-like proteins, and tegumental-allergen-like proteins. In addition to the evolutionary knowledge, the phylome data enabled us to automatically re-annotate 3,451 proteins through a phylogenetic-based approach rather than solely sequence similarity searches. To allow further exploitation of this valuable data, all information has been made available at PhylomeDB (http://www.phylomedb.org). In this study, we used an evolutionary approach to assess S. mansoni parasite biology, improve genome/proteome functional annotation, and provide insights into host-parasite interactions. Taking advantage of a proteome

  2. Prevalence of internal parasites in beef cows in the United States: Results of the National Animal Health Monitoring System's (NAHMS) beef study, 2007-2008.

    PubMed

    Stromberg, Bert E; Gasbarre, Louis C; Ballweber, Lora R; Dargatz, David A; Rodriguez, Judith M; Kopral, Christine A; Zarlenga, Dante S

    2015-10-01

    During the United States Department of Agriculture (USDA) National Animal Health Monitoring System's (NAHMS) 2007-2008 beef study, 567 producers from 24 US States were offered the opportunity to collect fecal samples from weaned beef calves and have them evaluated for the presence of parasite eggs (Phase 1). Participating producers were provided with instructions and materials for sample collection. Up to 20 fresh fecal samples were collected from each of the 99 participating operations. Fresh fecal samples were submitted to one of 3 randomly assigned laboratories for evaluation. Upon arrival at the laboratories, all samples were processed for the enumeration of strongyle, Nematodirus, and Trichuris eggs using the modified Wisconsin technique. The presence or absence of coccidian oocysts and tapeworm eggs was also noted. In submissions where the strongyle eggs per gram exceeded 30, aliquots from 2 to 6 animals were pooled for DNA extraction. Extracted DNA was subjected to genus level polymerase chain reaction (PCR) identification for the presence of Ostertagia, Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. In this study, 85.6% of the samples had strongyle type, Nematodirus, and Trichuris eggs. Among the samples evaluated, 91% had Cooperia, 79% Ostertagia, 53% Haemonchus, 38% Oesophagostomum, 18% Nematodirus, 7% Trichuris, and 3% Trichostrongylus. The prevalence of coccidia and tapeworm eggs was 59.9% and 13.7%, respectively.

  3. Phytomonas and other trypanosomatid parasites of plants and fruit.

    PubMed

    Camargo, E P

    1999-01-01

    Trypanosomatid parasites are fairly common in the latex, phloem, fruit sap, seed albumen, and even in the nectar, of many plant families. They are transmitted to the plants in the saliva of phytophagous hemipterous bugs (Insecta). Morphologically, plant trypanosomatids have no special characteristic, except perhaps a very twisted cell body. Most occur in plants as promastigotes and a few as choanomastigotes. It is still controversial whether or not they are pathogenic in lactiferous plants or fruit, but it is certain that the phloem parasites are pathogenic in coconut palms and coffee bushes. In these plants, they cause lethal diseases responsible for the destruction of many plantations in Central and South America, but fortunately nowhere else in the world. Probably more than one genus of Trypanosomatidae is represented among the plant parasites. The most important is certainly Phytomonas, but Leptomonas, Crithidia and Herpetomonas may also be present. The distinction between them is difficult and only recently have molecular markers become available to help in their identification. At present, Phytomonas can be identified by DNA hybridization with a specific probe (SL3') complementary to a sequence of the mini-exon or spliced leader gene. The development of a polymerase chain reaction coupled to SL3' hybridization has facilitated the detection of Phytomonas in plants. The phylogeny of Phytomonas is still being worked out. For the moment it can only be said that the genus is very close to Herpetomonas.

  4. Higher-level molecular phylogeny of the water mites (Acariformes: Prostigmata: Parasitengonina: Hydrachnidiae).

    PubMed

    Dabert, Miroslawa; Proctor, Heather; Dabert, Jacek

    2016-08-01

    With nearly 6000 named species, water mites (Hydrachnidiae) represent the largest group of arachnids to have invaded and extensively diversified in freshwater habitats. Water mites together with three other lineages (the terrestrial Erythraiae and Trombidiae, and aquatic Stygothrombiae), make up the hyporder Parasitengonina, which is characterized by having parasitic larvae and predatory nymphs and adults. Relationships between the Hydrachnidiae and other members of the Parasitengonina are unclear, as are relationships among the major lineages of water mites. Monophyly of water mites has been asserted, with the possible exception of the morphologically distinctive Hydrovolzioidea. Here we infer the phylogeny of water mites using multiple molecular markers and including representatives of all superfamilies of Hydrachnidiae and of almost all other Parasitengonina. Our results support a monophyletic Parasitengonina including Trombidiae, Stygothrombiae, and Hydrachnidiae. A monophyletic Hydrachnidiae, including Hydrovolzioidea, is strongly supported. Terrestrial Parasitengonina do not form a monophyletic sister group to water mites. Stygothrombiae is close to water mites but is not nested within this clade. Water mites appear to be derived from ancestors close to Stygothrombiae or the erythraoid group Calyptostomatoidea; however, this relationship is not clear because of extremely short branches in this part of the parasitengonine tree. We recovered with strong support all commonly accepted water mite superfamilies except for Hydryphantoidea, which is clearly paraphyletic. Our data support the previously proposed clades Protohydrachnidia (Hydrovolzioidea and Eylaoidea), Euhydrachnidia (all remaining superfamilies), and the euhydrachnid subclade Neohydrachnidia (Lebertioidea, Hydrachnoidea, Hygrobatoidea, and Arrenuroidea). We found that larval leg structure and locomotory behavior are strongly congruent with the molecular phylogeny. Other morphological and behavioral

  5. Echinococcus multilocularis and Echinococcus canadensis in wolves from western Canada.

    PubMed

    Schurer, Janna M; Gesy, Karen M; Elkin, Brett T; Jenkins, Emily J

    2014-02-01

    Echinococcus species are important parasites of wildlife, domestic animals and people worldwide; however, little is known about the prevalence, intensity and genetic diversity of Echinococcus tapeworms in Canadian wildlife. Echinococcus tapeworms were harvested from the intestines of 42% of 93 wolves (Canis lupus) from five sampling regions in the Northwest Territories, Manitoba and Saskatchewan, and visually identified to genus level by microscopic examination. Genetic characterization was successful for tapeworms from 30 wolves, and identified both Echinococcus canadensis and Echinococcus multilocularis in all sampling locations. Mixed infections of E. canadensis/E. multilocularis, as well as the G8/G10 genotypes of E. canadensis were observed. These findings suggest that wolves may be an important definitive host for both parasite species in western Canada. This represents the first report of wolves naturally infected with E. multilocularis in North America, and of wolves harbouring mixed infections with multiple species and genotypes of Echinococcus. These observations provide important information regarding the distribution and diversity of zoonotic species of Echinococcus in western North America, and may be of interest from public health and wildlife conservation perspectives.

  6. Phylogeny mandalas for illustrating the Tree of Life.

    PubMed

    Hasegawa, Masami

    2017-12-01

    A circular phylogeny with photos or drawings of species is named a phylogeny mandala. This is one of the ways for illustrating the Tree of Life, and is suitable to show visually how the biodiversity has developed in the course of evolution as clarified by the molecular phylogenetics. To demonstrate the recent progress of molecular phylogenetics, six phylogeny mandalas for various taxonomic groups of life were presented; i.e., (1) Eukaryota, (2) Metazoa, (3) Hexapoda, (4) Tetrapoda, (5) Eutheria, and (6) Primates. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Morphologic and Genetic Identification of Taenia Tapeworms in Tanzania and DNA Genotyping of Taenia solium

    PubMed Central

    Eom, Keeseon S.; Chai, Jong-Yil; Yong, Tai-Soon; Min, Duk-Young; Rim, Han-Jong; Kihamia, Charles

    2011-01-01

    Species identification of Taenia tapeworms was performed using morphologic observations and multiplex PCR and DNA sequencing of the mitochondrial cox1 gene. In 2008 and 2009, a total of 1,057 fecal samples were collected from residents of Kongwa district of Dodoma region, Tanzania, and examined microscopically for helminth eggs and proglottids. Of these, 4 Taenia egg positive cases were identified, and the eggs were subjected to DNA analysis. Several proglottids of Taenia solium were recovered from 1 of the 4 cases. This established that the species were T. solium (n=1) and T. saginata (n=3). One further T. solium specimen was found among 128 fecal samples collected from Mbulu district in Arusha, and this had an intact strobila with the scolex. Phylegenetic analysis of the mtDNA cox1 gene sequences of these 5 isolates showed that T. saginata was basal to the T. solium clade. The mitochondrial cox1 gene sequences of 3 of these Tanzanian isolates showed 99% similarity to T. saginata, and the other 2 isolates showed 100% similarity to T. solium. The present study has shown that Taenia tapeworms are endemic in Kongwa district of Tanzania, as well as in a previously identified Mbulu district. Both T. solium isolates were found to have an "African/Latin American" genotype (cox1). PMID:22355207

  8. Morphologic and genetic identification of Taenia tapeworms in Tanzania and DNA genotyping of Taenia solium.

    PubMed

    Eom, Keeseon S; Chai, Jong-Yil; Yong, Tai-Soon; Min, Duk-Young; Rim, Han-Jong; Kihamia, Charles; Jeon, Hyeong-Kyu

    2011-12-01

    Species identification of Taenia tapeworms was performed using morphologic observations and multiplex PCR and DNA sequencing of the mitochondrial cox1 gene. In 2008 and 2009, a total of 1,057 fecal samples were collected from residents of Kongwa district of Dodoma region, Tanzania, and examined microscopically for helminth eggs and proglottids. Of these, 4 Taenia egg positive cases were identified, and the eggs were subjected to DNA analysis. Several proglottids of Taenia solium were recovered from 1 of the 4 cases. This established that the species were T. solium (n = 1) and T. saginata (n = 3). One further T. solium specimen was found among 128 fecal samples collected from Mbulu district in Arusha, and this had an intact strobila with the scolex. Phylegenetic analysis of the mtDNA cox1 gene sequences of these 5 isolates showed that T. saginata was basal to the T. solium clade. The mitochondrial cox1 gene sequences of 3 of these Tanzanian isolates showed 99% similarity to T. saginata, and the other 2 isolates showed 100% similarity to T. solium. The present study has shown that Taenia tapeworms are endemic in Kongwa district of Tanzania, as well as in a previously identified Mbulu district. Both T. solium isolates were found to have an "African/Latin American" genotype (cox1).

  9. Parasites of sheep herding dogs in central Germany.

    PubMed

    Rehbein, Steffen; Kaulfuß, Karl-heinz; Visser, Martin; Sommer, Maria Franziska; Grimm, Felix; Silaghi, Cornelia

    2016-01-01

    This paper reports on endoparasite infections diagnosed in 2012 by standard coproscopical techniques and coproantigen Giardia ELISA in 165 dogs used for sheep herding in 36 farms in central Germany. The overall prevalence of dogs with evidence of endoparasite infections was 27.3% (95% CI 20.6-34.7). The most frequently identified faecal forms were those of ascarids (Toxocara, 6.7%; Toxascaris 3.6%), hookworms (5.5%) and taeniid cestodes (4.2%), followed by those of Trichuris whipworms (3.0%), Capillaria aerophila (1.8%), Angiostrongylus and Crenosoma lungworms (1.2% each) and Cystoisospora canis coccidians (0.6%). Molecular identification demonstrated the seven dogs shedding taeniid eggs positive for Taenia (T.) species tapeworms (five, T. hydatigena; one, T. ovis; one Taenia sp.). Screening of the faeces with the coproantigen ELISA revealed Giardia specific antigen in 5.5% of the samples. The majority of the dogs had evidence of single endoparasite infections (22.4%) while evidence for infection with two or three parasites concurrently was found in six (3.6%) and two (1.2%) of the dogs, respectively. Dogs ≤ 1 year (n = 19) were parasitized more frequently (p < 0.05) with overall gastrointestinal parasites (63.2% vs. 20.5%), ascarids (36.8% vs. 6.8%) and Giardia spp. (21.1% vs. 3.4%) than older dogs (n = 146). Dogs which had been wormed within six months of examination tested less frequently positive for gastrointestinal helminths compared to dogs not wormed (11.1% vs. 25.0%; p = 0.0567). In addition, ear swabs taken from 43 sheep dogs in 2012 were examined, and Otodectes cynotis mites were extracted from one dog. Identification of ectoparasites collected by full body search and combing from 113 sheep dogs in the years 2011 to 2013 revealed infestation of fleas and ticks (each up to five specimens per dog) on 13 and 108 dogs, respectively, with nine dogs carrying both fleas and ticks. Archaeopsylla erinacei, Ctenocephalides (C) canis, C. felis and Pulex irritans

  10. A case report of a Hymenolepis diminuta infection in a child in St James Parish, Jamaica.

    PubMed

    Cohen, I P

    1989-03-01

    Hymenolepsis diminuta is a tapeworm which is an intestinal parasite of rats and mice. Rarely, through accidental ingestion of an infected arthropod, man can become the definitive host. This report documents, for the first time, that such infections occur in Jamaica, West Indies. The life cycle of the parasite and its treatment are also discussed.

  11. Body size, trophic level, and the use of fish as transmission routes by parasites.

    PubMed

    Poulin, R; Leung, T L F

    2011-07-01

    Within food webs, trophically transmitted helminth parasites use predator-prey links for their own transfer from intermediate prey hosts, in which they occur as larval or juvenile stages, to predatory definitive hosts, in which they reach maturity. In large taxa that can be used as intermediate and/or definitive hosts, such as fish, a host species' position within a trophic network should determine whether its parasite fauna consists mostly of adult or larval helminths, since vulnerability to predation determines an animal's role in predator-prey links. Using a large database on the helminth parasites of 303 fish species, we tested whether the proportion of parasite species in a host that occur as larval or juvenile stages is best explained by their trophic level or by their body size. Independent of fish phylogeny or habitat, only fish body length emerged as a significant predictor of the proportion of parasites in a host that occur as larval stages from our multivariate analyses. On average, the proportion of larval helminth taxa in fish shorter than 20 cm was twice as high as that for fish over 100 cm in length. This is consistent with the prediction that small fishes, being more vulnerable to predation, make better hosts for larval parasites. However, trophic level and body length are strongly correlated among fish species, and they may have separate though confounded effects on the parasite fauna exploiting a given species. Helminths show varying levels of host specificity toward their intermediate host when the latter is the downstream host involved in trophic transmission toward an upstream definitive host. Given this broad physiological compatibility of many helminths with fish hosts, our results indicate that fish body length, as a proxy for vulnerability to predators, is a better predictor of their use by helminth larvae than their trophic level based on diet content.

  12. Prevalence of internal parasites in beef cows in the United States: Results of the National Animal Health Monitoring System’s (NAHMS) beef study, 2007–2008

    PubMed Central

    Stromberg, Bert E.; Gasbarre, Louis C.; Ballweber, Lora R.; Dargatz, David A.; Rodriguez, Judith M.; Kopral, Christine A.; Zarlenga, Dante S.

    2015-01-01

    During the United States Department of Agriculture (USDA) National Animal Health Monitoring System’s (NAHMS) 2007–2008 beef study, 567 producers from 24 US States were offered the opportunity to collect fecal samples from weaned beef calves and have them evaluated for the presence of parasite eggs (Phase 1). Participating producers were provided with instructions and materials for sample collection. Up to 20 fresh fecal samples were collected from each of the 99 participating operations. Fresh fecal samples were submitted to one of 3 randomly assigned laboratories for evaluation. Upon arrival at the laboratories, all samples were processed for the enumeration of strongyle, Nematodirus, and Trichuris eggs using the modified Wisconsin technique. The presence or absence of coccidian oocysts and tapeworm eggs was also noted. In submissions where the strongyle eggs per gram exceeded 30, aliquots from 2 to 6 animals were pooled for DNA extraction. Extracted DNA was subjected to genus level polymerase chain reaction (PCR) identification for the presence of Ostertagia, Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. In this study, 85.6% of the samples had strongyle type, Nematodirus, and Trichuris eggs. Among the samples evaluated, 91% had Cooperia, 79% Ostertagia, 53% Haemonchus, 38% Oesophagostomum, 18% Nematodirus, 7% Trichuris, and 3% Trichostrongylus. The prevalence of coccidia and tapeworm eggs was 59.9% and 13.7%, respectively. PMID:26424909

  13. Nematode parasites of fishes: recent advances and problems of their research.

    PubMed

    Moravec, F

    2007-09-01

    Although nematodes (Nematoda) belong to the most frequent and the most important parasites of fishes in the freshwater, brackish-water and marine environments throughout the world, the present knowledge of these parasites remains still incomplete, especially as to their biology and ecology, but also taxonomy, phylogeny, zoogeography, and the like. However, a certain progress in the research of fish nematodes has been achieved during recent years. An overview of some of the most important discoveries and results obtained is presented. As an example, existing problems in the taxonomy of these nematodes are shown in the dracunculoid family Philometridae (presently including 109 species in 9 genera), where they are associated mainly with some biological peculiarities of these mostly important tissue parasites. Nematodes of the Dracunculoidea as a whole remain poorly known; for example, of 139 valid species parasitizing fishes, 81 (58%) are known by females only and the males have not yet been described for members of 8 (27%) of genera. A taxonomic revision of this nematode group, based on detailed morphological, life history and molecular studies of individual species, is quite necessary; for the time being, Moravec (2006) has proposed a new classification system of dracunculoids, where, based on previous molecular studies, the Anguillicolidae is no longer listed in Dracunculoidea, but in an independent superfamily Anguillicoloidea. Important results have recently been achieved also in the taxonomy of fish nematodes belonging to other superfamilies, as well as in studies of their geographical distribution and diversity in different parts of the world and those of their biology. Opportunities for more detailed studies of fish nematodes have recently greatly improved with the use of some new methods, in particular SEM and DNA studies. There is a need to create a new classification system of these parasites reflecting phylogenetic relationships; a prerequisite for this is

  14. Juvenile morphology in baleen whale phylogeny.

    PubMed

    Tsai, Cheng-Hsiu; Fordyce, R Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  15. Hidden diversity of Nycteribiidae (Diptera) bat flies from the Malagasy region and insights on host-parasite interactions.

    PubMed

    Ramasindrazana, Beza; Goodman, Steven M; Gomard, Yann; Dick, Carl W; Tortosa, Pablo

    2017-12-29

    We present information on Nycteribiidae flies parasitizing the bat families Pteropodidae, Miniopteridae and Vespertilionidae from the Malagasy Region, contributing insight into their diversity and host preference. Our phylogenetic analysis identified nine clusters of nycteribiid bat flies on Madagascar and the neighbouring Comoros Archipelago. Bat flies sampled from frugivorous bats of the family Pteropodidae are monoxenous: Eucampsipoda madagascariensis, E. theodori and Cyclopodia dubia appear wholly restricted to Rousettus madagascariensis, R. obliviosus and Eidolon dupreanum, respectively. Two different host preference patterns occurred in nycteribiids infecting insectivorous bats. Flies parasitizing bats of the genera Miniopterus (Miniopteridae) and Myotis (Vespertilionidae), namely Penicillidia leptothrinax, Penicillidia sp. and Nycteribia stylidiopsis, are polyxenous and showed little host preference, while those parasitizing the genera Pipistrellus and Scotophilus (both Vespertilionidae) and referable to Basilia spp., are monoxenous. Lastly, the inferred Bayesian phylogeny revealed that the genus Basilia, as currently configured, is paraphyletic. This study provides new information on the differentiation of nycteribiid taxa, including undescribed species. Host preference is either strict as exemplified by flies parasitizing fruit bats, or more relaxed as found on some insectivorous bat species, possibly because of roost site sharing. Detailed taxonomic work is needed to address three undescribed nycteribiid taxa found on Pipistrellus and Scotophilus, tentatively allocated to the genus Basilia, but possibly warranting different generic allocation.

  16. On simulated annealing phase transitions in phylogeny reconstruction.

    PubMed

    Strobl, Maximilian A R; Barker, Daniel

    2016-08-01

    Phylogeny reconstruction with global criteria is NP-complete or NP-hard, hence in general requires a heuristic search. We investigate the powerful, physically inspired, general-purpose heuristic simulated annealing, applied to phylogeny reconstruction. Simulated annealing mimics the physical process of annealing, where a liquid is gently cooled to form a crystal. During the search, periods of elevated specific heat occur, analogous to physical phase transitions. These simulated annealing phase transitions play a crucial role in the outcome of the search. Nevertheless, they have received comparably little attention, for phylogeny or other optimisation problems. We analyse simulated annealing phase transitions during searches for the optimal phylogenetic tree for 34 real-world multiple alignments. In the same way in which melting temperatures differ between materials, we observe distinct specific heat profiles for each input file. We propose this reflects differences in the search landscape and can serve as a measure for problem difficulty and for suitability of the algorithm's parameters. We discuss application in algorithmic optimisation and as a diagnostic to assess parameterisation before computationally costly, large phylogeny reconstructions are launched. Whilst the focus here lies on phylogeny reconstruction under maximum parsimony, it is plausible that our results are more widely applicable to optimisation procedures in science and industry. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Phylogeny of the Paracalanidae Giesbrecht, 1888 (Crustacea: Copepoda: Calanoida).

    PubMed

    Cornils, Astrid; Blanco-Bercial, Leocadio

    2013-12-01

    The Paracalanidae are ecologically-important marine planktonic copepods that occur in the epipelagic zone in temperate and tropical waters. They are often the dominant taxon - in terms of biomass and abundance - in continental shelf regions. As primary consumers, they form a vital link in the pelagic food web between primary producers and higher trophic levels. Despite the ecological importance of the taxon, evolutionary and systematic relationships within the family remain largely unknown. A multigene phylogeny including 24 species, including representatives for all seven genera, was determined based on two nuclear genes, small-subunit (18S) ribosomal RNA and Histone 3 (H3) and one mitochondrial gene, cytochrome c oxidase subunit I (COI). The molecular phylogeny was well supported by Maximum likelihood and Bayesian inference analysis; all genera were found to be monophyletic, except for Paracalanus, which was separated into two distinct clades: the Paracalanus aculeatus group and Paracalanus parvus group. The molecular phylogeny also confirmed previous findings that Mecynocera and Calocalanus are genera of the family Paracalanidae. For comparison, a morphological phylogeny was created for 35 paracalanid species based on 54 morphological characters derived from published descriptions. The morphological phylogeny did not resolve all genera as monophyletic and bootstrap support was not strong. Molecular and morphological phylogenies were not congruent in the positioning of Bestiolina and the Paracalanus species groups, possibly due to the lack of sufficient phylogenetically-informative morphological characters. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Occurrence, hosts, morphology, and molecular characterisation of Pasteuria bacteria parasitic in nematodes of the family Plectidae.

    PubMed

    Sturhan, Dieter; Shutova, Tatyana S; Akimov, Vladimir N; Subbotin, Sergei A

    2005-01-01

    Parasitic bacteria of the genus Pasteuria are reported for three Anaplectus and four identified and several unidentified Plectus species found in eight countries in various habitats. The pasteurias from plectids agree in essential morphological characters of sporangia and endospores as well as in developmental cycle with those of the Pasteuria species and strains described from tylenchid nematodes, but appear to be mainly distinguished from these by absence of a distinct perisporium in the spores and the endospores obviously not being cup- or saucer-shaped. The wide range of measurements and morphological peculiarities of sporangia and endospores suggest that probably several Pasteuria species have to be distinguished as parasites in Plectidae. From an infected juvenile of an unidentified plectid species the 16S rRNA gene sequence of Pasteuria sp. was obtained. Substantial sequence divergence from described Pasteuria species and its phylogenetic position on molecular trees indicate that this Pasteuria sp. could be considered as a new species. Preliminary results of the analysis of DNA phylogeny of Pasteuria spp. and their nematode hosts provide evidence for incongruence of their phylogenetic history and of host switching events during evolution of the bacterial parasites.

  19. Molecular Identification of Zoonotic Tissue-Invasive Tapeworm Larvae Other than Taenia solium in Suspected Human Cysticercosis Cases.

    PubMed

    Tappe, Dennis; Berkholz, Jörg; Mahlke, Uwe; Lobeck, Hartmut; Nagel, Thomas; Haeupler, Alexandra; Muntau, Birgit; Racz, Paul; Poppert, Sven

    2016-01-01

    Rarely, zoonotic Taenia species other than Taenia solium cause human cysticercosis. The larval stages are morphologically often indistinguishable. We therefore investigated 12 samples of suspected human cysticercosis cases at the molecular level and surprisingly identified one Taenia crassiceps and one Taenia serialis (coenurosis) infection, which were caused by tapeworm larvae normally infecting rodents and sheep via eggs released from foxes and dogs. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  20. Ribosomal RNA: a key to phylogeny

    NASA Technical Reports Server (NTRS)

    Olsen, G. J.; Woese, C. R.

    1993-01-01

    As molecular phylogeny increasingly shapes our understanding of organismal relationships, no molecule has been applied to more questions than have ribosomal RNAs. We review this role of the rRNAs and some of the insights that have been gained from them. We also offer some of the practical considerations in extracting the phylogenetic information from the sequences. Finally, we stress the importance of comparing results from multiple molecules, both as a method for testing the overall reliability of the organismal phylogeny and as a method for more broadly exploring the history of the genome.

  1. Primate diversification inferred from phylogenies and fossils.

    PubMed

    Herrera, James P

    2017-12-01

    Biodiversity arises from the balance between speciation and extinction. Fossils record the origins and disappearance of organisms, and the branching patterns of molecular phylogenies allow estimation of speciation and extinction rates, but the patterns of diversification are frequently incongruent between these two data sources. I tested two hypotheses about the diversification of primates based on ∼600 fossil species and 90% complete phylogenies of living species: (1) diversification rates increased through time; (2) a significant extinction event occurred in the Oligocene. Consistent with the first hypothesis, analyses of phylogenies supported increasing speciation rates and negligible extinction rates. In contrast, fossils showed that while speciation rates increased, speciation and extinction rates tended to be nearly equal, resulting in zero net diversification. Partially supporting the second hypothesis, the fossil data recorded a clear pattern of diversity decline in the Oligocene, although diversification rates were near zero. The phylogeny supported increased extinction ∼34 Ma, but also elevated extinction ∼10 Ma, coinciding with diversity declines in some fossil clades. The results demonstrated that estimates of speciation and extinction ignoring fossils are insufficient to infer diversification and information on extinct lineages should be incorporated into phylogenetic analyses. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  2. RPS8—a New Informative DNA Marker for Phylogeny of Babesia and Theileria Parasites in China

    PubMed Central

    Tian, Zhan-Cheng; Liu, Guang-Yuan; Yin, Hong; Luo, Jian-Xun; Guan, Gui-Quan; Luo, Jin; Xie, Jun-Ren; Shen, Hui; Tian, Mei-Yuan; Zheng, Jin-feng; Yuan, Xiao-song; Wang, Fang-fang

    2013-01-01

    Piroplasmosis is a serious debilitating and sometimes fatal disease. Phylogenetic relationships within piroplasmida are complex and remain unclear. We compared the intron–exon structure and DNA sequences of the RPS8 gene from Babesia and Theileria spp. isolates in China. Similar to 18S rDNA, the 40S ribosomal protein S8 gene, RPS8, including both coding and non-coding regions is a useful and novel genetic marker for defining species boundaries and for inferring phylogenies because it tends to have little intra-specific variation but considerable inter-specific difference. However, more samples are needed to verify the usefulness of the RPS8 (coding and non-coding regions) gene as a marker for the phylogenetic position and detection of most Babesia and Theileria species, particularly for some closely related species. PMID:24244571

  3. Epsiprantel, a new tapeworm remedy. Preliminary efficacy studies in dogs and cats.

    PubMed

    Manger, B R; Brewer, M D

    1989-01-01

    The anthelmintic potential of epsiprantel, 2-(cyclohexylcarbonyl)-4-oxo-1,2,3,4,6,7,8,12b-octahydropyrazin [2,1-a] [2]benzapine, was revealed using the tapeworms Dipylidium caninum and Taenia taeniaeformis in the cat, and Taenia pisiformis and T. hydatigena in the dog. Subsequent controlled tests in cats demonstrated oral efficacy of 100% against D. caninum with a single dose of 2.5 mg/kg. Although consistently 100% effective against T. taeniaeformis at 5 mg/kg, a single worm was found in one cat treated at 7.5 mg/kg. In experimental infections of Taenia pisiformis in dogs, 100% activity was achieved from a single oral dose of 1 mg/kg. No adverse reaction or drug-associated toxicity were observed at dose levels used.

  4. microRNAs in parasites and parasite infection

    PubMed Central

    Zheng, Yadong; Cai, Xuepeng; Bradley, Janette E.

    2013-01-01

    miRNAs, a subclass of small regulatory RNAs, are present from ancient unicellular protozoans to parasitic helminths and parasitic arthropods. The miRNA-silencing mechanism appears, however, to be absent in a number of protozoan parasites. Protozoan miRNAs and components of their silencing machinery possess features different from other eukaryotes, providing some clues on the evolution of the RNA-induced silencing machinery. miRNA functions possibly associate with neoblast biology, development, physiology, infection and immunity of parasites. Parasite infection can alter host miRNA expression that can favor both parasite clearance and infection. miRNA pathways are, thus, a potential target for the therapeutic control of parasitic diseases. PMID:23392243

  5. Molecular evidence of cryptic diversity in Paracaryophyllaeus (Cestoda: Caryophyllidea), parasites of loaches (Cobitidae) in Eurasia, including description of P. vladkae n. sp.

    PubMed

    Scholz, Tomáš; Oros, Mikuláš; Bazsalovicsová, Eva; Brabec, Jan; Waeschenbach, Andrea; Xi, Bing-Wen; Aydoğdu, Ali; Besprozvannykh, Vladimir; Shimazu, Takeshi; Králová-Hromadová, Ivica; Littlewood, D Timothy J

    2014-12-01

    Molecular phylogenetic analysis of an extensive collection of monozoic tapeworms of the genus Paracaryophyllaeus Kulakovskaya, 1961 (Cestoda: Caryophyllidea), parasites of loaches (Cypriniformes: Cobitidae) in Eurasia, has revealed cryptic species diversity within this long-time monotypic genus, especially in the Paracaryophyllaeus gotoi (Motomura, 1927) species complex [syn. Paracaryophyllaeus dubininorum (Kulakovskaya, 1961); type species]. Three independent, well-supported clades were discovered on the basis of molecular data: (i) specimens from Misgurnus anguillicaudatus and Cobitis lutheri from China, Russian Far East and Japan - called herein P. cf. gotoi 1, which may be conspecific with P. gotoi (Motomura, 1927), although in the absence of sequence data for P. gotoi from its type locality (basin of the River Kumkan in Korea), no certain inferences about their identity can currently be made; (ii) specimens from M. anguillicaudatus from China and Japan - P. cf. gotoi 2, which are morphologically indistinguishable from those of P. cf. gotoi 1; and (iii) morphologically distinct tapeworms from the endemic loach Cobitis bilseli from southwestern Turkey (Beyşehir Lake), which are described herein as a new species. Paracaryophyllaeus vladkae Scholz, Oros and Aydoğdu n. sp. differs from the remaining species of the genus in the following characteristics: the testes begin anterior to the first vitelline follicles (versus posterior), the body is short and robust (versus more elongate and slender), and the scolex is wide, rounded or apically tapered (versus claviform to truncate). Species composition of the genus, host specificity of species and geographical distribution are briefly discussed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Evidence for intercontinental parasite exchange through molecular detection and characterization of haematozoa in northern pintails (Anas acuta) sampled throughout the North Pacific Basin.

    PubMed

    Ramey, Andrew M; Schmutz, Joel A; Reed, John A; Fujita, Go; Scotton, Bradley D; Casler, Bruce; Fleskes, Joseph P; Konishi, Kan; Uchida, Kiyoshi; Yabsley, Michael J

    2015-04-01

    Empirical evidence supports wild birds as playing a role in the interhemispheric exchange of bacteria and viruses; however, data supporting the redistribution of parasites among continents are limited. In this study, the hypothesis that migratory birds contribute to the redistribution of parasites between continents was tested by sampling northern pintails (Anas acuta) at locations throughout the North Pacific Basin in North America and East Asia for haemosporidian infections and assessing the genetic evidence for parasite exchange. Of 878 samples collected from birds in Alaska (USA), California (USA), and Hokkaido (Japan) during August 2011-May 2012 and screened for parasitic infections using molecular techniques, Leucocytozoon, Haemoproteus, and Plasmodium parasites were detected in 555 (63%), 44 (5%), and 52 (6%) samples, respectively. Using an occupancy modeling approach, the probability of detecting parasites via replicate genetic tests was estimated to be high (ρ > 0.95). Multi-model inference supported variation of Leucocytozoon parasite prevalence by northern pintail age class and geographic location of sampling in contrast to Haemoproteus and Plasmodium parasites for which there was only support for variation in parasite prevalence by sampling location. Thirty-one unique mitochondrial DNA haplotypes were detected among haematozoa infecting northern pintails including seven lineages shared between samples from North America and Japan. The finding of identical parasite haplotypes at widely distributed geographic locations and general lack of genetic structuring by continent in phylogenies for Leucocytozoon and Plasmodium provides evidence for intercontinental genetic exchange of haemosporidian parasites. Results suggest that migratory birds, including waterfowl, could therefore facilitate the introduction of avian malaria and other haemosporidia to novel hosts and spatially distant regions.

  7. Evidence for intercontinental parasite exchange through molecular detection and characterization of haematozoa in northern pintails (Anas acuta) sampled throughout the North Pacific Basin

    PubMed Central

    Ramey, Andrew M.; Schmutz, Joel A.; Reed, John A.; Fujita, Go; Scotton, Bradley D.; Casler, Bruce; Fleskes, Joseph P.; Konishi, Kan; Uchida, Kiyoshi; Yabsley, Michael J.

    2014-01-01

    Empirical evidence supports wild birds as playing a role in the interhemispheric exchange of bacteria and viruses; however, data supporting the redistribution of parasites among continents are limited. In this study, the hypothesis that migratory birds contribute to the redistribution of parasites between continents was tested by sampling northern pintails (Anas acuta) at locations throughout the North Pacific Basin in North America and East Asia for haemosporidian infections and assessing the genetic evidence for parasite exchange. Of 878 samples collected from birds in Alaska (USA), California (USA), and Hokkaido (Japan) during August 2011–May 2012 and screened for parasitic infections using molecular techniques, Leucocytozoon, Haemoproteus, and Plasmodium parasites were detected in 555 (63%), 44 (5%), and 52 (6%) samples, respectively. Using an occupancy modeling approach, the probability of detecting parasites via replicate genetic tests was estimated to be high (ρ > 0.95). Multi-model inference supported variation of Leucocytozoon parasite prevalence by northern pintail age class and geographic location of sampling in contrast to Haemoproteus and Plasmodium parasites for which there was only support for variation in parasite prevalence by sampling location. Thirty-one unique mitochondrial DNA haplotypes were detected among haematozoa infecting northern pintails including seven lineages shared between samples from North America and Japan. The finding of identical parasite haplotypes at widely distributed geographic locations and general lack of genetic structuring by continent in phylogenies for Leucocytozoon and Plasmodium provides evidence for intercontinental genetic exchange of haemosporidian parasites. Results suggest that migratory birds, including waterfowl, could therefore facilitate the introduction of avian malaria and other haemosporidia to novel hosts and spatially distant regions. PMID:25830100

  8. Evidence for intercontinental parasite exchange through molecular detection and characterization of haematozoa in northern pintails (Anas acuta) sampled throughout the North Pacific Basin

    USGS Publications Warehouse

    Ramey, Andy M.; Schmutz, Joel A.; Reed, John A.; Fujita, Go; Scotton, Bradley D.; Casler, Bruce; Fleskes, Joseph P.; Konishi, Kan; Uchida, Kiyoshi; Yabsley, Michael J.

    2015-01-01

    Empirical evidence supports wild birds as playing a role in the interhemispheric exchange of bacteria and viruses; however, data supporting the redistribution of parasites among continents are limited. In this study, the hypothesis that migratory birds contribute to the redistribution of parasites between continents was tested by sampling northern pintails (Anas acuta) at locations throughout the North Pacific Basin in North America and East Asia for haemosporidian infections and assessing the genetic evidence for parasite exchange. Of 878 samples collected from birds in Alaska (USA), California (USA), and Hokkaido (Japan) during August 2011 - May 2012 and screened for parasitic infections using molecular techniques, Leucocytozoon, Haemoproteus, and Plasmodium parasites were detected in 555 (63%), 44 (5%), and 52 (6%) samples, respectively. Using an occupancy modeling approach, the probability of detecting parasites via replicate genetic tests was estimated to be high (p ≥ 0.95). Multi-model inference supported variation of Leucocytozoon parasite prevalence by northern pintail age class and geographic location of sampling in contrast to Haemoproteus and Plasmodium parasites for which there was only support for variation in parasite prevalence by sampling location. Thirty-one unique mitochondrial DNA haplotypes were detected among haematozoa infecting northern pintails including seven lineages shared between samples from North America and Japan. The finding of identical parasite haplotypes at widely distributed geographic locations and general lack of genetic structuring by continent in phylogenies for Leucocytozoon and Plasmodium provides evidence for intercontinental genetic exchange of haemosporidian parasites. Results suggest that migratory birds, including waterfowl, could therefore facilitate the introduction of avian malaria and other haemosporidia to novel hosts and spatially distant regions.

  9. Parasitism and mutualism in Wolbachia: what the phylogenomic trees can and cannot say.

    PubMed

    Bordenstein, Seth R; Paraskevopoulos, Charalampos; Dunning Hotopp, Julie C; Sapountzis, Panagiotis; Lo, Nathan; Bandi, Claudio; Tettelin, Hervé; Werren, John H; Bourtzis, Kostas

    2009-01-01

    -heterogenous models of evolution did improve the placement of aberrant taxa in the ingroup phylogeny. Finally, in the unrooted topology, the distribution of parasitism and mutualism across the tree suggests that at least two interphylum transfers shaped the origins of nematode mutualism and arthropod parasitism. We suggest that the ancestry of mutualism and parasitism is not resolvable without more suitable outgroups or complete genome sequences from all Wolbachia supergroups.

  10. Different meal, same flavor: cospeciation and host switching of haemosporidian parasites in some non-passerine birds

    PubMed Central

    2014-01-01

    Background Previous studies have shown that haemosporidian parasites (Haemoproteus (Parahaemoproteus) and Plasmodium) infecting passerine birds have an evolutionary history of host switching with little cospeciation, in particular at low taxonomic levels (e.g., below the family level), which is suggested as the main speciation mechanism of this group of parasites. Recent studies have characterized diverse clades of haemosporidian parasites (H. (Haemoproteus) and H. (Parahaemoproteus)) infecting non-passerine birds (e.g., Columbiformes, Pelecaniiformes). Here, we explore the cospeciation history of H. (Haemoproteus) and H. (Parahaemoproteus) parasites with their non-passerine hosts. Methods We sequenced the mtDNA cyt b gene of both haemosporidian parasites and their avian non-passerine hosts. We built Bayesian phylogenetic hypotheses and created concensus phylograms that were subsequently used to conduct cospeciation analyses. We used both a global cospeciation test, PACo, and an event-cost algorithm implemented in CoRe-PA. Results The global test suggests that H. (Haemoproteus) and H. (Parahaemoproteus) parasites have a diversification history dominated by cospeciation events particularly at the family level. Host-parasite links from the PACo analysis show that host switching events are common within families (i.e., among genera and among species within genera), and occasionally across different orders (e.g., Columbiformes to Pelecaniiformes). Event-cost analyses show that haemosporidian coevolutionary history is dominated by host switching and some codivergence, but with duplication events also present. Genetic lineages unique to raptor species (e.g., FALC11) commonly switch between Falconiformes and Strigiformes. Conclusions Our results corroborate previous findings that have detected a global cospeciation signal at the family taxonomic level, and they also support a history of frequent switching closer to the tips of the host phylogeny, which seems to be the

  11. Multiple Convergent Origins of Workerlessness and Inbreeding in the Socially Parasitic Ant Genus Myrmoxenus.

    PubMed

    Heinze, Jürgen; Buschinger, Alfred; Poettinger, Theo; Suefuji, Masaki

    2015-01-01

    The socially parasitic ant genus Myrmoxenus varies strongly in fundamental life history traits, such as queen-worker ratio, the timing of sexual production, and mating behavior. Myrmoxenus queens generally take over nests of Temnothorax ants, kill the resident queen by throttling, and force the workers to take care of the social parasite's brood. Young queens of M. ravouxi and other species produce large numbers of workers, which during "slave-raids" pillage host pupae from neighboring Temnothorax colonies to increase the workforce in their own nests. Other species, such as M. corsicus, have lost caste polyphenism and rear only male and female sexual offspring. Using sequences of the genes CO I/CO II and wingless we reconstruct the phylogeny of Myrmoxenus and document that the worker caste was lost convergently at least three times. Furthermore, mating in the nest and inbreeding obviously also evolved in parallel from ancestors whose sexuals presumably mated during nuptial flights. Myrmoxenus might thus provide a suitable model to investigate caste differentiation and the plasticity of mating behavior in Hymenoptera.

  12. [Diphyllobothrium pacificum (Nybelin,1931) margolis, 1956 in Canis familiaris from Chincha city, Peru].

    PubMed

    Cabrera, R; Tantaleán, M; Rojas, R

    2001-01-01

    In this communication is presented the finding of the tapeworm Diphyllobothrium pacificum, parasite of sea lions, in Canis familiaris (dog) in Chincha city, Peru. This is the first canine infection with D. pacificum in the South Peruvian coast.

  13. Molecular taxonomy and phylogeny

    USDA-ARS?s Scientific Manuscript database

    The cyst nematodes comprise a group of sedentary endoparasitic nematodes that impact a wide range of crops in both tropical and temperate regions of the world. This chapter updates the taxonomy and phylogeny of this group and describes the nuclear protein coding, ribosomal, and mitochondrial sequenc...

  14. Plastome phylogeny and early diversification of Brassicaceae.

    PubMed

    Guo, Xinyi; Liu, Jianquan; Hao, Guoqian; Zhang, Lei; Mao, Kangshan; Wang, Xiaojuan; Zhang, Dan; Ma, Tao; Hu, Quanjun; Al-Shehbaz, Ihsan A; Koch, Marcus A

    2017-02-16

    The family Brassicaceae encompasses diverse species, many of which have high scientific and economic importance. Early diversifications and phylogenetic relationships between major lineages or clades remain unclear. Here we re-investigate Brassicaceae phylogeny with complete plastomes from 51 species representing all four lineages or 5 of 6 major clades (A, B, C, E and F) as identified in earlier studies. Bayesian and maximum likelihood phylogenetic analyses using a partitioned supermatrix of 77 protein coding genes resulted in nearly identical tree topologies exemplified by highly supported relationships between clades. All four lineages were well identified and interrelationships between them were resolved. The previously defined Clade C was found to be paraphyletic (the genus Megadenia formed a separate lineage), while the remaining clades were monophyletic. Clade E (lineage III) was sister to clades B + C rather than to all core Brassicaceae (clades A + B + C or lineages I + II), as suggested by a previous transcriptome study. Molecular dating based on plastome phylogeny supported the origin of major lineages or clades between late Oligocene and early Miocene, and the following radiative diversification across the family took place within a short timescale. In addition, gene losses in the plastomes occurred multiple times during the evolutionary diversification of the family. Plastome phylogeny illustrates the early diversification of cruciferous species. This phylogeny will facilitate our further understanding of evolution and adaptation of numerous species in the model family Brassicaceae.

  15. Building a Twig Phylogeny

    ERIC Educational Resources Information Center

    Flinn, Kathryn M.

    2015-01-01

    In this classroom activity, students build a phylogeny for woody plant species based on the morphology of their twigs. Using any available twigs, students can practice the process of cladistics to test evolutionary hypotheses for real organisms. They identify homologous characters, determine polarity through outgroup comparison, and construct a…

  16. Using MOEA with Redistribution and Consensus Branches to Infer Phylogenies.

    PubMed

    Min, Xiaoping; Zhang, Mouzhao; Yuan, Sisi; Ge, Shengxiang; Liu, Xiangrong; Zeng, Xiangxiang; Xia, Ningshao

    2017-12-26

    In recent years, to infer phylogenies, which are NP-hard problems, more and more research has focused on using metaheuristics. Maximum Parsimony and Maximum Likelihood are two effective ways to conduct inference. Based on these methods, which can also be considered as the optimal criteria for phylogenies, various kinds of multi-objective metaheuristics have been used to reconstruct phylogenies. However, combining these two time-consuming methods results in those multi-objective metaheuristics being slower than a single objective. Therefore, we propose a novel, multi-objective optimization algorithm, MOEA-RC, to accelerate the processes of rebuilding phylogenies using structural information of elites in current populations. We compare MOEA-RC with two representative multi-objective algorithms, MOEA/D and NAGA-II, and a non-consensus version of MOEA-RC on three real-world datasets. The result is, within a given number of iterations, MOEA-RC achieves better solutions than the other algorithms.

  17. Molecular phylogeny of Arthrotardigrada (Tardigrada).

    PubMed

    Jørgensen, Aslak; Faurby, Søren; Hansen, Jesper G; Møbjerg, Nadja; Kristensen, Reinhardt M

    2010-03-01

    Tardigrades are microscopic ecdysozoans with a worldwide distribution covering marine, limnic and terrestrial habitats. They are regarded as a neglected phylum with regard to studies of their phylogeny. During the last decade molecular data have been included in the investigation of tardigrades. However, the marine arthrotardigrades are still poorly sampled due to their relative rarity, difficult identification and minute size even for tardigrades. In the present study, we have sampled various arthrotardigrades and sequenced the 18S and partial 28S ribosomal subunits. The phylogenetic analyses based on Bayesian inference and maximum parsimony inferred Heterotardigrada (Arthrotardigrada+Echiniscoidea) and Eutardigrada to be monophyletic. Arthrotardigrada was inferred to be paraphyletic as the monophyletic Echiniscoidea is included within the arthrotardigrades. The phylogenetic positions of Stygarctidae and Batillipedidae are poorly resolved with low branch support. The Halechiniscidae is inferred to be polyphyletic as the currently recognized Styraconyxinae is not part of the family. Archechiniscus is the sister-group to the Halechiniscidae and Orzeliscus is placed as one of the basal halechiniscids. The phylogeny of the included eutardigrade taxa resembles the current molecular phylogenies. The genetic diversity within Arthrotardigrada is much larger (18S 15.1-26.5%, 28S 7.2-20.7%) than within Eutardigrada (18S 1.0-12.6%, 28S 1.3-8.2%). This can be explained by higher substitution rates in the arthrotardigrades or by a much younger evolutionary age of the sampled eutardigrades. Copyright 2009 Elsevier Inc. All rights reserved.

  18. Redescription of Corallobothrium solidum (Cestoda: Proteocephalidea) and erection of a new genus, Essexiella, for tapeworms from channel catfishes (Ictaluridae).

    PubMed

    Scholz, Tomáš; de Chambrier, Alain; Mariaux, Jean; Kuchta, Roman

    2011-12-01

    The proteocephalidean tapeworm, Corallobothrium solidum, type species of the genus, is redescribed on the basis of the examination of its type specimens and extensive material recently collected from Malapterurus electricus (type host). Some morphological characteristics of taxonomic importance are reported for the first time, such as the presence of semispherical (U-shaped) sphincters on the external (outer) margin of the suckers, a vaginal sphincter, a well-developed seminal receptacle, and a unique morphology of the eggs. Corallobothrium solidum differs from the 2 remaining species of the genus, both parasitic in channel catfishes (Ictaluridae), in its scolex shape, morphology of its suckers, presence of longitudinal and transverse grooves on the body surface, dense network of excretory canals in the apical part of the scolex, morphology of the eggs, and uterine development. The non-monophyletic nature of Corallobothrium is further supported by molecular data (partial sequences of the 28S rRNA gene) because C. solidum and the 2 remaining species from ictalurids do not form a monophyletic assemblage. Therefore, Essexiella n. gen. is proposed to accommodate Essexiella fimbriatum new comb. (type and only species; syn. Corallobothrium fimbriatum) from channel catfish. Essexiella n. gen. differs from Corallobothrium, Megathylacoides, and Megathylacus by the absence of a sphincter in the suckers, from Corallotaenia by the shape of the scolex and the number and shape of proglottids, and from Paraproteocephalus by the structure of the uterus. The diagnosis of Corallobothrium, which becomes monotypic and restricted to electric catfishes in Africa, is emended. The remaining species of Corallobothrium, Corallobothrium parafimbriatum, is tentatively transferred to Corallotaenia as Corallotaenia parafimbriata n. comb., based on molecular data, small size of the strobila, and shape of the scolex.

  19. Phylogeny predicts future habitat shifts due to climate change.

    PubMed

    Kuntner, Matjaž; Năpăruş, Magdalena; Li, Daiqin; Coddington, Jonathan A

    2014-01-01

    Taxa may respond differently to climatic changes, depending on phylogenetic or ecological effects, but studies that discern among these alternatives are scarce. Here, we use two species pairs from globally distributed spider clades, each pair representing two lifestyles (generalist, specialist) to test the relative importance of phylogeny versus ecology in predicted responses to climate change. We used a recent phylogenetic hypothesis for nephilid spiders to select four species from two genera (Nephilingis and Nephilengys) that match the above criteria, are fully allopatric but combined occupy all subtropical-tropical regions. Based on their records, we modeled each species niche spaces and predicted their ecological shifts 20, 40, 60, and 80 years into the future using customized GIS tools and projected climatic changes. Phylogeny better predicts the species current ecological preferences than do lifestyles. By 2080 all species face dramatic reductions in suitable habitat (54.8-77.1%) and adapt by moving towards higher altitudes and latitudes, although at different tempos. Phylogeny and life style explain simulated habitat shifts in altitude, but phylogeny is the sole best predictor of latitudinal shifts. Models incorporating phylogenetic relatedness are an important additional tool to predict accurately biotic responses to global change.

  20. Phylogeny and adaptation shape the teeth of insular mice

    PubMed Central

    Ledevin, Ronan; Chevret, Pascale; Ganem, Guila; Britton-Davidian, Janice; Hardouin, Emilie A.; Chapuis, Jean-Louis; Pisanu, Benoit; da Luz Mathias, Maria; Schlager, Stefan; Auffray, Jean-Christophe; Renaud, Sabrina

    2016-01-01

    By accompanying human travels since prehistorical times, the house mouse dispersed widely throughout the world, and colonized many islands. The origin of the travellers determined the phylogenetic source of the insular mice, which encountered diverse ecological and environmental conditions on the various islands. Insular mice are thus an exceptional model to disentangle the relative role of phylogeny, ecology and climate in evolution. Molar shape is known to vary according to phylogeny and to respond to adaptation. Using for the first time a three-dimensional geometric morphometric approach, compared with a classical two-dimensional quantification, the relative effects of size variation, phylogeny, climate and ecology were investigated on molar shape diversity across a variety of islands. Phylogeny emerged as the factor of prime importance in shaping the molar. Changes in competition level, mostly driven by the presence or absence of the wood mouse on the different islands, appeared as the second most important effect. Climate and size differences accounted for slight shape variation. This evidences a balanced role of random differentiation related to history of colonization, and of adaptation possibly related to resource exploitation. PMID:26842576

  1. Phylogeny and adaptation shape the teeth of insular mice.

    PubMed

    Ledevin, Ronan; Chevret, Pascale; Ganem, Guila; Britton-Davidian, Janice; Hardouin, Emilie A; Chapuis, Jean-Louis; Pisanu, Benoit; da Luz Mathias, Maria; Schlager, Stefan; Auffray, Jean-Christophe; Renaud, Sabrina

    2016-02-10

    By accompanying human travels since prehistorical times, the house mouse dispersed widely throughout the world, and colonized many islands. The origin of the travellers determined the phylogenetic source of the insular mice, which encountered diverse ecological and environmental conditions on the various islands. Insular mice are thus an exceptional model to disentangle the relative role of phylogeny, ecology and climate in evolution. Molar shape is known to vary according to phylogeny and to respond to adaptation. Using for the first time a three-dimensional geometric morphometric approach, compared with a classical two-dimensional quantification, the relative effects of size variation, phylogeny, climate and ecology were investigated on molar shape diversity across a variety of islands. Phylogeny emerged as the factor of prime importance in shaping the molar. Changes in competition level, mostly driven by the presence or absence of the wood mouse on the different islands, appeared as the second most important effect. Climate and size differences accounted for slight shape variation. This evidences a balanced role of random differentiation related to history of colonization, and of adaptation possibly related to resource exploitation. © 2016 The Author(s).

  2. When integration fails: Prokaryote phylogeny and the tree of life.

    PubMed

    O'Malley, Maureen A

    2013-12-01

    Much is being written these days about integration, its desirability and even its necessity when complex research problems are to be addressed. Seldom, however, do we hear much about the failure of such efforts. Because integration is an ongoing activity rather than a final achievement, and because today's literature about integration consists mostly of manifesto statements rather than precise descriptions, an examination of unsuccessful integration could be illuminating to understand better how it works. This paper will examine the case of prokaryote phylogeny and its apparent failure to achieve integration within broader tree-of-life accounts of evolutionary history (often called 'universal phylogeny'). Despite the fact that integrated databases exist of molecules pertinent to the phylogenetic reconstruction of all lineages of life, and even though the same methods can be used to construct phylogenies wherever the organisms fall on the tree of life, prokaryote phylogeny remains at best only partly integrated within tree-of-life efforts. I will examine why integration does not occur, compare it with integrative practices in animal and other eukaryote phylogeny, and reflect on whether there might be different expectations of what integration should achieve. Finally, I will draw some general conclusions about integration and its function as a 'meta-heuristic' in the normative commitments guiding scientific practice. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Phylogeny with introgression in Habronattus jumping spiders (Araneae: Salticidae).

    PubMed

    Leduc-Robert, Geneviève; Maddison, Wayne P

    2018-02-22

    Habronattus is a diverse clade of jumping spiders with complex courtship displays and repeated evolution of Y chromosomes. A well-resolved species phylogeny would provide an important framework to study these traits, but has not yet been achieved, in part because the few genes available in past studies gave conflicting signals. Such discordant gene trees could be the result of incomplete lineage sorting (ILS) in recently diverged parts of the phylogeny, but there are indications that introgression could be a source of conflict. To infer Habronattus phylogeny and investigate the cause of gene tree discordance, we assembled transcriptomes for 34 Habronattus species and 2 outgroups. The concatenated 2.41 Mb of nuclear data (1877 loci) resolved phylogeny by Maximum Likelihood (ML) with high bootstrap support (95-100%) at most nodes, with some uncertainty surrounding the relationships of H. icenoglei, H. cambridgei, H. oregonensis, and Pellenes canadensis. Species tree analyses by ASTRAL and SVDQuartets gave almost completely congruent results. Several nodes in the ML phylogeny from 12.33 kb of mitochondrial data are incongruent with the nuclear phylogeny and indicate possible mitochondrial introgression: the internal relationships of the americanus and the coecatus groups, the relationship between the altanus, decorus, banksi, and americanus group, and between H. clypeatus and the coecatus group. To determine the relative contributions of ILS and introgression, we analyzed gene tree discordance for nuclear loci longer than 1 kb using Bayesian Concordance Analysis (BCA) for the americanus group (679 loci) and the VCCR clade (viridipes/clypeatus/coecatus/roberti groups) (517 loci) and found signals of introgression in both. Finally, we tested specifically for introgression in the concatenated nuclear matrix with Patterson's D statistics and D FOIL . We found nuclear introgression resulting in substantial admixture between americanus group species, between H. roberti

  4. Short report: cysticercosis in an Egyptian mummy of the late Ptolemaic period.

    PubMed

    Bruschi, Fabrizio; Masetti, Massimo; Locci, Maria Teresa; Ciranni, Rosalba; Fornaciari, Gino

    2006-04-01

    We describe here an ancient case of cysticercosis that was discovered in an Egyptian mummy of a young woman of about 20 years of age who lived in the late Ptolemaic period (second to first centuries b.c.). On removal of the stomach and its rehydration, a cystic lesion in the stomach wall was observed by naked eye. Microscopical examination of sections of this lesion revealed a cystic structure, with a wall, with numerous projecting eversions, a characteristic feature of the larval stage (cysticercus) of the human tapeworm Taenia solium (or "pig tapeworm"). Immunohistochemical testing with serum from a T. solium-infected human confirmed the identity of the cyst. This finding is the oldest on record of the antiquity of this zoonotic parasite. This observation also confirms that, in Hellenistic Egypt, the farming of swine, along with man an intermediate host of this parasite, was present, and supports other archeological evidence.

  5. Comparative development of Taenia solium in experimental models.

    PubMed

    Maravilla, P; Avila, G; Cabrera, V; Aguilar, L; Flisser, A

    1998-10-01

    Various mammals were evaluated as experimental models of adult Taenia solium. Suppressed and nonsuppressed hosts were used as experimental models. Infections were performed per os with cysticerci obtained from pigs; immunosuppression was induced with methyl prednisolone acetate at intervals of 10-14 days after infection. Tapeworms developed in hamsters, gerbils, and chinchillas but failed to develop in rabbits, cats, pigs, and rhesus monkeys. In infectable animals, treatment with the steroid facilitated maintenance and development of the parasite, and more tapeworms were obtained. Mature and some pregravid proglottids were recovered from hamsters and gerbils, whereas a gravid T. solium was obtained from a chinchilla at 12 wk postinfection. Eggs recovered from the chinchilla transformed into cysticerci in a pig 12 wk after oral infection. The T. solium-chinchilla experimental system seems to be an alternative definitive host for this parasite and thus the basis for a great diversity of studies.

  6. 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.

  7. [Epidemiology and prevention of echinococcosis in France].

    PubMed

    Petavy, A F; Deblock, S; Walbaum, S

    1990-01-21

    Echinococcosis is a cosmopolitan parasitic disease caused by the larvae of two tapeworms: Echinococcus granulosus responsible for unilocular hydatidosis, and Echinococcus multilocularis responsible for alveolar hydatid disease. In both cases man is infected by ingesting eggs of these tapeworms belonging to the genus Cestoda. In France, the only animal that acts as definitive host and transmits the unilocular type of hydatid disease is the dog, while the alveolar type is transmitted by dogs, foxes and cats. Carnivorous pet animals must be taken into account in the prevention of echinococcosis, whether their role is direct or indirect (fouling plants).

  8. Differential parasitism of seed-feeding Cydia (Lepidoptera: Tortricidae) by native and alien wasp species relative to elevation in subalpine Sophora (Fabaceae) forests on Mauna Kea, Hawaii

    USGS Publications Warehouse

    Oboyski, P.T.; Slotterback, J.W.; Banko, P.C.

    2004-01-01

    Alien parasitic wasps, including accidental introductions and purposefully released biological control agents, have been implicated in the decline of native Hawaiian Lepidoptera. Understanding the potential impacts of alien wasps requires knowledge of ecological parameters that influence parasitism rates for species in their new environment. Sophora seed-feeding Cydia spp. (Lepidoptera: Tortricidae) were surveyed for larval parasitoids to determine how native and alien wasps are partitioned over an elevation gradient (2200-2800 m) on Hawaii Island, Hawaii. Parasitism rate of native Euderus metallicus (Eulophidae) increased with increased elevation, while parasitism rate by immigrant Calliephialtes grapholithae (Ichneumonidae) decreased. Parasitism by Pristomerus hawaiiensis (Ichneumonidae), origins uncertain, also decreased with increased elevation. Two other species, Diadegma blackburni (Ichneumonidae), origins uncertain, and Brasema cushmani (Eupelmidae), a purposefully introduced biological control agent for pepper weevil, did not vary significantly with elevation. Results are contrasted with a previous study of this system with implications for the conservation of an endangered bird species that feed on Cydia larvae. Interpretation of results is hindered by lack of knowledge of autecology of moths and wasps, origins, phylogeny, systematics, competitive ability, and physiological limitations of each wasp species. These factors should be incorporated into risk analysis for biological control introductions and invasive species programs. ?? 2004 Kluwer Academic Publishers.

  9. Paternity-parasitism trade-offs: a model and test of host-parasite cooperation in an avian conspecific brood parasite.

    PubMed

    Lyon, Bruce E; Hochachka, Wesley M; Eadie, John M

    2002-06-01

    Efforts to evaluate the evolutionary and ecological dynamics of conspecific brood parasitism in birds and other animals have focused on the fitness costs of parasitism to hosts and fitness benefits to parasites. However, it has been speculated recently that, in species with biparental care, host males might cooperate with parasitic females by allowing access to the host nest in exchange for copulations. We develop a cost-benefit model to explore the conditions under which such host-parasite cooperation might occur. When the brood parasite does not have a nest of her own, the only benefit to the host male is siring some of the parasitic eggs (quasi-parasitism). Cooperation with the parasite is favored when the ratio of host male paternity of his own eggs relative to his paternity of parasitic eggs exceeds the cost of parasitism. When the brood parasite has a nest of her own, a host male can gain additional, potentially more important benefits by siring the high-value, low-cost eggs laid by the parasite in her own nest. Under these conditions, host males should be even more likely to accept parasitic eggs in return for copulations with the parasitic female. We tested these predictions for American coots (Fulica americana), a species with a high frequency of conspecific brood parasitism. Multilocus DNA profiling indicated that host males did not sire any of the parasitic eggs laid in host nests, nor did they sire eggs laid by the parasite in her own nest. We used field estimates of the model parameters from a four-year study of coots to predict the minimum levels of paternity required for the costs of parasitism to be offset by the benefits of mating with brood parasites. Observed levels of paternity were significantly lower than those predicted under a variety of assumptions, and we reject the hypothesis that host males cooperated with parasitic females. Our model clarifies the specific costs and benefits that influence host-parasite cooperation and, more generally

  10. Human Bertiella studeri in Spain, probably of African origin.

    PubMed

    Galan-Puchades, M T; Fuentes, M V; Mas-Coma, S

    1997-06-01

    A mature tapeworm and gravid proglottids of Bertiella studeri were reported from the stools of a 33-year-old pregnant Spanish woman. The patient had spent the six months preceding this discovery in Kenya. The evidence suggests a case of parasitism imported to Spain from the African continent. The patient presented no symptoms related to the parasite and the discovery in stools of a number of active, white structures led her to collect them. A morphologic and morphometric description of the material obtained is presented. Mebendazole failed to remove the parasite but niclosamide was effective.

  11. A supermatrix phylogeny of corvoid passerine birds (Aves: Corvides).

    PubMed

    Jønsson, Knud Andreas; Fabre, Pierre-Henri; Kennedy, Jonathan D; Holt, Ben G; Borregaard, Michael K; Rahbek, Carsten; Fjeldså, Jon

    2016-01-01

    The Corvides (previously referred to as the core Corvoidea) are a morphologically diverse clade of passerine birds comprising nearly 800 species. The group originated some 30 million years ago in the proto-Papuan archipelago, to the north of Australia, from where lineages have dispersed and colonized all of the world's major continental and insular landmasses (except Antarctica). During the last decade multiple species-level phylogenies have been generated for individual corvoid families and more recently the inter-familial relationships have been resolved, based on phylogenetic analyses using multiple nuclear loci. In the current study we analyse eight nuclear and four mitochondrial loci to generate a dated phylogeny for the majority of corvoid species. This phylogeny includes 667 out of 780 species (85.5%), 141 out of 143 genera (98.6%) and all 31 currently recognized families, thus providing a baseline for comprehensive macroecological, macroevolutionary and biogeographical analyses. Using this phylogeny we assess the temporal consistency of the current taxonomic classification of families and genera. By adopting an approach that enforces temporal consistency by causing the fewest possible taxonomic changes to currently recognized families and genera, we find the current familial classification to be largely temporally consistent, whereas that of genera is not. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Dipylidium (Dog and Cat Flea Tapeworm) FAQs

    MedlinePlus

    ... Page last updated: January 10, 2012 Content source: Global Health – Division of Parasitic Diseases Email Recommend Tweet YouTube Instagram Listen Watch RSS ABOUT About CDC Jobs Funding LEGAL Policies Privacy FOIA No Fear Act OIG 1600 Clifton ...

  13. Interacting parasites

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2010-01-01

    Parasitism is the most popular life-style on Earth, and many vertebrates host more than one kind of parasite at a time. A common assumption is that parasite species rarely interact, because they often exploit different tissues in a host, and this use of discrete resources limits competition (1). On page 243 of this issue, however, Telfer et al. (2) provide a convincing case of a highly interactive parasite community in voles, and show how infection with one parasite can affect susceptibility to others. If some human parasites are equally interactive, our current, disease-by-disease approach to modeling and treating infectious diseases is inadequate (3).

  14. Discovery-based studies of schistosome diversity stimulate new hypotheses about parasite biology

    PubMed Central

    Brant, Sara V.; Loker, Eric S.

    2013-01-01

    This review provides an update of ongoing efforts to expand our understanding of the diversity inherent within the Schistosomatidae, the parasites responsible for causing schistosomiasis and cercarial dermatitis. By revealing more of the species present, particularly among under-studied avian schistosomes, we gain increased understanding of patterns of schistosome diversification, and their abilities to colonize new hosts and habitats. Schistosomes reveal a surprising ability to switch into new snail and vertebrate host species, into new intra-host habitats, and may adopt novel body forms in the process. Often these changes are not associated with deep splits or long branches in their phylogeny, suggesting they are of relatively recent origin. Several hypotheses prompted by the new observations are discussed, helping to focus thinking on processes influencing not only schistosome diversification, but also their pathogenicity and abundance. PMID:23849836

  15. Timing and Order of Transmission Events Is Not Directly Reflected in a Pathogen Phylogeny

    PubMed Central

    Romero-Severson, Ethan; Skar, Helena; Bulla, Ingo; Albert, Jan; Leitner, Thomas

    2014-01-01

    Pathogen phylogenies are often used to infer spread among hosts. There is, however, not an exact match between the pathogen phylogeny and the host transmission history. Here, we examine in detail the limitations of this relationship. First, all splits in a pathogen phylogeny of more than 1 host occur within hosts, not at the moment of transmission, predating the transmission events as described by the pretransmission interval. Second, the order in which nodes in a phylogeny occur may be reflective of the within-host dynamics rather than epidemiologic relationships. To investigate these phenomena, motivated by within-host diversity patterns, we developed a two-phase coalescent model that includes a transmission bottleneck followed by linear outgrowth to a maximum population size followed by either stabilization or decline of the population. The model predicts that the pretransmission interval shrinks compared with predictions based on constant population size or a simple transmission bottleneck. Because lineages coalesce faster in a small population, the probability of a pathogen phylogeny to resemble the transmission history depends on when after infection a donor transmits to a new host. We also show that the probability of inferring the incorrect order of multiple transmissions from the same host is high. Finally, we compare time of HIV-1 infection informed by genetic distances in phylogenies to independent biomarker data, and show that, indeed, the pretransmission interval biases phylogeny-based estimates of when transmissions occurred. We describe situations where caution is needed not to misinterpret which parts of a phylogeny that may indicate outbreaks and tight transmission clusters. PMID:24874208

  16. Molecular and phylogenetic characterization of honey bee viruses, Nosema microsporidia, protozoan parasites, and parasitic mites in China.

    PubMed

    Yang, Bu; Peng, Guangda; Li, Tianbang; Kadowaki, Tatsuhiko

    2013-02-01

    China has the largest number of managed honey bee colonies, which produce the highest quantity of honey and royal jelly in the world; however, the presence of honey bee pathogens and parasites has never been rigorously identified in Chinese apiaries. We thus conducted a molecular survey of honey bee RNA viruses, Nosema microsporidia, protozoan parasites, and tracheal mites associated with nonnative Apis mellifera ligustica and native Apis cerana cerana colonies in China. We found the presence of black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), and sacbrood virus (SBV), but not that of acute bee paralysis virus (ABPV) or Kashmir bee virus (KBV). DWV was the most prevalent in the tested samples. Phylogenies of Chinese viral isolates demonstrated that genetically heterogeneous populations of BQCV, CBPV, DWV, and A. cerana-infecting SBV, and relatively homogenous populations of IAPV and A. meliifera-infecting new strain of SBV with single origins, are spread in Chinese apiaries. Similar to previous observations in many countries, Nosema ceranae, but not Nosema apis, was prevalent in the tested samples. Crithidia mellificae, but not Apicystis bombi was found in five samples, including one A. c. cerana colony, demonstrating that C. mellificae is capable of infecting multiple honey bee species. Based on kinetoplast-encoded cytochrome b sequences, the C. mellificae isolate from A. c. cerana represents a novel haplotype with 19 nucleotide differences from the Chinese and Japanese isolates from A. m. ligustica. This suggests that A. c. cerana is the native host for this specific haplotype. The tracheal mite, Acarapis woodi, was detected in one A. m. ligustica colony. Our results demonstrate that honey bee RNA viruses, N. ceranae, C. mellificae, and tracheal mites are present in Chinese apiaries, and some might be originated from native Asian honey bees.

  17. A six-gene phylogeny provides new insights into choanoflagellate evolution.

    PubMed

    Carr, Martin; Richter, Daniel J; Fozouni, Parinaz; Smith, Timothy J; Jeuck, Alexandra; Leadbeater, Barry S C; Nitsche, Frank

    2017-02-01

    Recent studies have shown that molecular phylogenies of the choanoflagellates (Class Choanoflagellatea) are in disagreement with their traditional taxonomy, based on morphology, and that Choanoflagellatea requires considerable taxonomic revision. Furthermore, phylogenies suggest that the morphological and ecological evolution of the group is more complex than has previously been recognized. Here we address the taxonomy of the major choanoflagellate order Craspedida, by erecting four new genera. The new genera are shown to be morphologically, ecologically and phylogenetically distinct from other choanoflagellate taxa. Furthermore, we name five novel craspedid species, as well as formally describe ten species that have been shown to be either misidentified or require taxonomic revision. Our revised phylogeny, including 18 new species and sequence data for two additional genes, provides insights into the morphological and ecological evolution of the choanoflagellates. We examine the distribution within choanoflagellates of these two additional genes, EF-1A and EFL, closely related translation GTPases which are required for protein synthesis. Mapping the presence and absence of these genes onto the phylogeny highlights multiple events of gene loss within the choanoflagellates. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Phylogenomic Reconstruction of the Oomycete Phylogeny Derived from 37 Genomes

    PubMed Central

    McCarthy, Charley G. P.

    2017-01-01

    ABSTRACT The oomycetes are a class of microscopic, filamentous eukaryotes within the Stramenopiles-Alveolata-Rhizaria (SAR) supergroup which includes ecologically significant animal and plant pathogens, most infamously the causative agent of potato blight Phytophthora infestans. Single-gene and concatenated phylogenetic studies both of individual oomycete genera and of members of the larger class have resulted in conflicting conclusions concerning species phylogenies within the oomycetes, particularly for the large Phytophthora genus. Genome-scale phylogenetic studies have successfully resolved many eukaryotic relationships by using supertree methods, which combine large numbers of potentially disparate trees to determine evolutionary relationships that cannot be inferred from individual phylogenies alone. With a sufficient amount of genomic data now available, we have undertaken the first whole-genome phylogenetic analysis of the oomycetes using data from 37 oomycete species and 6 SAR species. In our analysis, we used established supertree methods to generate phylogenies from 8,355 homologous oomycete and SAR gene families and have complemented those analyses with both phylogenomic network and concatenated supermatrix analyses. Our results show that a genome-scale approach to oomycete phylogeny resolves oomycete classes and individual clades within the problematic Phytophthora genus. Support for the resolution of the inferred relationships between individual Phytophthora clades varies depending on the methodology used. Our analysis represents an important first step in large-scale phylogenomic analysis of the oomycetes. IMPORTANCE The oomycetes are a class of eukaryotes and include ecologically significant animal and plant pathogens. Single-gene and multigene phylogenetic studies of individual oomycete genera and of members of the larger classes have resulted in conflicting conclusions concerning interspecies relationships among these species, particularly for the

  19. Host specificity and genealogy of the louse Polyplax serrata on field mice, Apodemus species: a case of parasite duplication or colonisation?

    PubMed

    Stefka, Jan; Hypsa, Václav

    2008-05-01

    The genealogy, population structure and population dynamics of the sucking louse Polyplax serrata were analysed across four host species of the genus Apodemus. An analysis of 126 sequences of cytochrome c oxidase subunit I using phylogenetic approaches and haplotype networking revealed a clear structure of European samples, forming three distinct and genetically distant clades with different host specificities. Although a clear connection was detected between the host and parasite genealogies/phylogenies, a uniform pattern of co-speciation was not found. For example, a dramatic shift in the degree of host specificity was demonstrated for two related louse lineages living in sympatry and sharing one of their host species. While one of the louse lineages frequently parasitised two different host taxa (Apodemus sylvaticus and Apodemus flavicollis), the other louse lineage was strictly specific to A. flavicollis. The estimate of divergence time between the two louse lineages indicates that they may have arisen due to parasite duplication on A. flavicollis.

  20. Cultivation of parasites.

    PubMed

    Ahmed, Nishat Hussain

    2014-07-01

    Parasite cultivation techniques constitute a substantial segment of present-day study of parasites, especially of protozoa. Success in establishing in vitro and in vivo culture of parasites not only allows their physiology, behavior and metabolism to be studied dynamically, but also allows the nature of the antigenic molecules in the excretory and secretory products to be vigorously pursued and analyzed. The complex life-cycles of various parasites having different stages and host species requirements, particularly in the case of parasitic helminths, often make parasite cultivation an uphill assignment. Culturing of parasites depends on the combined expertise of all types of microbiological cultures. Different parasites require different cultivation conditions such as nutrients, temperature and even incubation conditions. Cultivation is an important method for diagnosis of many clinically important parasites, for example, Entamoeba histolytica, Trichomonas vaginalis, Leishmania spp., Strongyloides stercoralis and free-living amoebae. Many commercial systems like InPouch TV for T. vaginalis, microaerophilous stationary phase culture for Babesia bovis and Harada-Mori culture technique for larval-stage nematodes have been developed for the rapid diagnosis of the parasitic infections. Cultivation also has immense utility in the production of vaccines, testing vaccine efficacy, and antigen - production for obtaining serological reagents, detection of drug-resistance, screening of potential therapeutic agents and conducting epidemiological studies. Though in vitro cultivation techniques are used more often compared with in vivo techniques, the in vivo techniques are sometimes used for diagnosing some parasitic infections such as trypanosomiasis and toxoplasmosis. Parasite cultivation continues to be a challenging diagnostic option. This review provides an overview of intricacies of parasitic culture and update on popular methods used for cultivating parasites.

  1. Cultivation of parasites

    PubMed Central

    Ahmed, Nishat Hussain

    2014-01-01

    Parasite cultivation techniques constitute a substantial segment of present-day study of parasites, especially of protozoa. Success in establishing in vitro and in vivo culture of parasites not only allows their physiology, behavior and metabolism to be studied dynamically, but also allows the nature of the antigenic molecules in the excretory and secretory products to be vigorously pursued and analyzed. The complex life-cycles of various parasites having different stages and host species requirements, particularly in the case of parasitic helminths, often make parasite cultivation an uphill assignment. Culturing of parasites depends on the combined expertise of all types of microbiological cultures. Different parasites require different cultivation conditions such as nutrients, temperature and even incubation conditions. Cultivation is an important method for diagnosis of many clinically important parasites, for example, Entamoeba histolytica, Trichomonas vaginalis, Leishmania spp., Strongyloides stercoralis and free-living amoebae. Many commercial systems like InPouch TV for T. vaginalis, microaerophilous stationary phase culture for Babesia bovis and Harada-Mori culture technique for larval-stage nematodes have been developed for the rapid diagnosis of the parasitic infections. Cultivation also has immense utility in the production of vaccines, testing vaccine efficacy, and antigen - production for obtaining serological reagents, detection of drug-resistance, screening of potential therapeutic agents and conducting epidemiological studies. Though in vitro cultivation techniques are used more often compared with in vivo techniques, the in vivo techniques are sometimes used for diagnosing some parasitic infections such as trypanosomiasis and toxoplasmosis. Parasite cultivation continues to be a challenging diagnostic option. This review provides an overview of intricacies of parasitic culture and update on popular methods used for cultivating parasites. PMID

  2. Syphacia obvelata (Nematode, Oxyuridae) infecting laboratory mice Mus musculus (Rodentia, Muridae): phylogeny and host-parasite relationship.

    PubMed

    Abdel-Gaber, Rewaida

    2016-03-01

    Syphacia obvelata is a pinworm nematode parasite infecting man and laboratory animals in high abundance. This parasitological study was carried out during the period of March 2014-February 2015 to investigate the helminth parasites infecting the laboratory mice Mus musculus in the Animal House at Cairo University, Egypt. The prevalence of S. obvelata in M. musculus was 75.0 %. The extent of infection with S. obvelata is analyzed according to the sex of the host mice. It was shown that the prevalence of male infection was greater than female worms. Morphological characterization revealed that the present Oxyurid species possesses a rounded cephalic end with less developed lips, esophagus divided into cylindrical corpus, and globular bulb supported internally with valvular apparatus; three mamelons are located at the ventral surface with a single chitinized spicule and a gubernaculum provided with an accessory hook in males, and ovijector apparatus opens ventrally by the vulva surrounded by protruded lips in female worms. Body of the male was 0.623-1.130 (0.830 ± 0.11) mm long and 0.092-0.130 (0.110 ± 0.01) mm wide; the esophagus was 0.164-0.280 (0.210 ± 0.01) mm long; the nerve ring and excretory pore are located at 0.035-0.132 (0.073 ± 0.01) and 0.087-0.191 (0.145 ± 0.01) mm from the anterior end, respectively, while the female measured 2.930-4.650 (3.540 ± 0.1) mm long and 0.120-0.232 (0.156 ± 0.001) mm wide; the esophagus was 0.213-0.410 (0.342 ± 0.01) mm long; the nerve ring, excretory pore, and vulval opening are located at 0.026-0.157 (0.121 ± 0.01), 0.134-0.243 (0.195 ± 0.01), and 0.323-0.632 (0.546 ± 0.11) mm from the anterior end, respectively; eggs measured 0.120-0.139 (0.129 ± 0.001) mm long and 0.030-0.052 (0.045 ± 0.001) mm wide. It compared morphometrically with other Syphacia species described previously and showed little differences in

  3. Identifying wildlife reservoirs of neglected taeniid tapeworms: Non-invasive diagnosis of endemic Taenia serialis infection in a wild primate population

    PubMed Central

    Griffin, Randi H.; Gomery, Megan A.; Dorny, Pierre; Noh, John C.; Handali, Sukwan; Chastain, Holly M.; Wilkins, Patricia P.; Nunn, Charles L.; Snyder-Mackler, Noah; Beehner, Jacinta C.; Bergman, Thore J.

    2017-01-01

    Despite the global distribution and public health consequences of Taenia tapeworms, the life cycles of taeniids infecting wildlife hosts remain largely undescribed. The larval stage of Taenia serialis commonly parasitizes rodents and lagomorphs, but has been reported in a wide range of hosts that includes geladas (Theropithecus gelada), primates endemic to Ethiopia. Geladas exhibit protuberant larval cysts indicative of advanced T. serialis infection that are associated with high mortality. However, non-protuberant larvae can develop in deep tissue or the abdominal cavity, leading to underestimates of prevalence based solely on observable cysts. We adapted a non-invasive monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) to detect circulating Taenia spp. antigen in dried gelada urine. Analysis revealed that this assay was highly accurate in detecting Taenia antigen, with 98.4% specificity, 98.5% sensitivity, and an area under the curve of 0.99. We used this assay to investigate the prevalence of T. serialis infection in a wild gelada population, finding that infection is substantially more widespread than the occurrence of visible T. serialis cysts (16.4% tested positive at least once, while only 6% of the same population exhibited cysts). We examined whether age or sex predicted T. serialis infection as indicated by external cysts and antigen presence. Contrary to the female-bias observed in many Taenia-host systems, we found no significant sex bias in either cyst presence or antigen presence. Age, on the other hand, predicted cyst presence (older individuals were more likely to show cysts) but not antigen presence. We interpret this finding to indicate that T. serialis may infect individuals early in life but only result in visible disease later in life. This is the first application of an antigen ELISA to the study of larval Taenia infection in wildlife, opening the doors to the identification and description of infection dynamics in reservoir

  4. Identifying wildlife reservoirs of neglected taeniid tapeworms: Non-invasive diagnosis of endemic Taenia serialis infection in a wild primate population.

    PubMed

    Schneider-Crease, India; Griffin, Randi H; Gomery, Megan A; Dorny, Pierre; Noh, John C; Handali, Sukwan; Chastain, Holly M; Wilkins, Patricia P; Nunn, Charles L; Snyder-Mackler, Noah; Beehner, Jacinta C; Bergman, Thore J

    2017-07-01

    Despite the global distribution and public health consequences of Taenia tapeworms, the life cycles of taeniids infecting wildlife hosts remain largely undescribed. The larval stage of Taenia serialis commonly parasitizes rodents and lagomorphs, but has been reported in a wide range of hosts that includes geladas (Theropithecus gelada), primates endemic to Ethiopia. Geladas exhibit protuberant larval cysts indicative of advanced T. serialis infection that are associated with high mortality. However, non-protuberant larvae can develop in deep tissue or the abdominal cavity, leading to underestimates of prevalence based solely on observable cysts. We adapted a non-invasive monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) to detect circulating Taenia spp. antigen in dried gelada urine. Analysis revealed that this assay was highly accurate in detecting Taenia antigen, with 98.4% specificity, 98.5% sensitivity, and an area under the curve of 0.99. We used this assay to investigate the prevalence of T. serialis infection in a wild gelada population, finding that infection is substantially more widespread than the occurrence of visible T. serialis cysts (16.4% tested positive at least once, while only 6% of the same population exhibited cysts). We examined whether age or sex predicted T. serialis infection as indicated by external cysts and antigen presence. Contrary to the female-bias observed in many Taenia-host systems, we found no significant sex bias in either cyst presence or antigen presence. Age, on the other hand, predicted cyst presence (older individuals were more likely to show cysts) but not antigen presence. We interpret this finding to indicate that T. serialis may infect individuals early in life but only result in visible disease later in life. This is the first application of an antigen ELISA to the study of larval Taenia infection in wildlife, opening the doors to the identification and description of infection dynamics in reservoir

  5. 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.

  6. [Metazoan parasites of Micropterus salmoides (Centrarchidae: Perciformes) from reservoirs of Nuevo León, México and their association with condition factor and gender].

    PubMed

    Galaviz S, Lucio; Escobar G, Baldemar; Iruegas B, Francisco Javier; Molina, Zinnia Judith

    2016-06-01

    The largemouth bass Micropterus salmoides is a very valuable fish species for aquaculture and sport fishing; however, there are no systematic studies on fish metazoan parasites in Mexico. The main objective of the present study was to describe the prevalence, abundance, and intensity of M. salmoides metazoan parasites, and their association with fish condition factor and gender. The sample size was composed by 672 hosts, collected between 2011-2013 from the following reservoirs of Nuevo Leon, México: Rodrigo Gómez dam (“La Boca”, LB), Cuchillo-Solidaridad dam (CS), Salinillas lagoon (LS), Mariano Escobedo dam (“Sombreretillo”, S), and José López Portillo dam (“Cerro Prieto”, CP). Living fish were transported to the laboratory; sizes and weights were then recorded to calculate the Fulton condition factor (k). If possible, gender was also recorded. Parasites were detected under stereoscopy, recollected and preserved by traditional techniques. Statistical analysis of association between parasitic load, gender, and Fulton condition factor were calculated, using the X2 and the Student-t tests. Results showed that 12 different metazoans were identified, two flukes (Posthodiplostomum minimum centrarchi and Phyllodistomum pearsei), one tapeworm (Proteocephalus ambloplitis), three roundworms (Contracaecum sp., Spinitectus carolini and Philometra nodulosa), two acantocephalan (Neoechinorhynchus cylindratus and Arhythmorhynchus sp.), one leech (Myzobdella moorei), and three copepods (Ergasilus versicolor; Ergasilus arthrosis and Ergasilus cerastes). HSD Tukey test showed that infected fish from LB were significantly different than LS, CS, CP, and S (P<0.05). Parasites most commonly collected in all five locations were P. m. centrarchi, Contracaecum sp. and E. versicolor. The frequency of P. m. centrarchi was highly significant (P<0.001) than other parasites; furthermore, this parasite showed the highest prevalence (97.5 %), abundance (10.12-83.6), and

  7. Principles of cophylogenetic maps

    NASA Astrophysics Data System (ADS)

    Charleston, Michael A.

    Cophylogeny is the study of the relationships between phylogenies of ecologically related groups (taxa, geographical areas, genes etc.), where one, the "host" phylogeny, is independent and the other, the "associate" phylogeny, is hypothesized to be dependent to some degree on the host. Given two such phylogenies our aim is to estimate the past associations between the host and associate taxa. This chapter describes cophylogeny and discusses some of its basic pri nciples. The necessary properties of any cophylogenetic method are described. Charleston [5] created a graph which contains all the potential solutions to a given cophylogenetic problem. The vertices of this graph are associations, either observed or hypothetical, between "host" and associated taxonomic units, and the arcs correspond to the associate phylogeny. A new and more general method of constructing the Jungle is presented, which will correctly account for reticulate host and/or parasite phylogenies. Keywords: cophylogeny, coevolution, gene tree/species tree, host/parasite coevolution, host switch, horizontal transfer, biogeography.

  8. Comparative evolutionary diversity and phylogenetic structure across multiple forest dynamics plots: a mega-phylogeny approach

    PubMed Central

    Erickson, David L.; Jones, Frank A.; Swenson, Nathan G.; Pei, Nancai; Bourg, Norman A.; Chen, Wenna; Davies, Stuart J.; Ge, Xue-jun; Hao, Zhanqing; Howe, Robert W.; Huang, Chun-Lin; Larson, Andrew J.; Lum, Shawn K. Y.; Lutz, James A.; Ma, Keping; Meegaskumbura, Madhava; Mi, Xiangcheng; Parker, John D.; Fang-Sun, I.; Wright, S. Joseph; Wolf, Amy T.; Ye, W.; Xing, Dingliang; Zimmerman, Jess K.; Kress, W. John

    2014-01-01

    Forest dynamics plots, which now span longitudes, latitudes, and habitat types across the globe, offer unparalleled insights into the ecological and evolutionary processes that determine how species are assembled into communities. Understanding phylogenetic relationships among species in a community has become an important component of assessing assembly processes. However, the application of evolutionary information to questions in community ecology has been limited in large part by the lack of accurate estimates of phylogenetic relationships among individual species found within communities, and is particularly limiting in comparisons between communities. Therefore, streamlining and maximizing the information content of these community phylogenies is a priority. To test the viability and advantage of a multi-community phylogeny, we constructed a multi-plot mega-phylogeny of 1347 species of trees across 15 forest dynamics plots in the ForestGEO network using DNA barcode sequence data (rbcL, matK, and psbA-trnH) and compared community phylogenies for each individual plot with respect to support for topology and branch lengths, which affect evolutionary inference of community processes. The levels of taxonomic differentiation across the phylogeny were examined by quantifying the frequency of resolved nodes throughout. In addition, three phylogenetic distance (PD) metrics that are commonly used to infer assembly processes were estimated for each plot [PD, Mean Phylogenetic Distance (MPD), and Mean Nearest Taxon Distance (MNTD)]. Lastly, we examine the partitioning of phylogenetic diversity among community plots through quantification of inter-community MPD and MNTD. Overall, evolutionary relationships were highly resolved across the DNA barcode-based mega-phylogeny, and phylogenetic resolution for each community plot was improved when estimated within the context of the mega-phylogeny. Likewise, when compared with phylogenies for individual plots, estimates of

  9. 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...

  10. Explaining evolution via constrained persistent perfect phylogeny

    PubMed Central

    2014-01-01

    Background The perfect phylogeny is an often used model in phylogenetics since it provides an efficient basic procedure for representing the evolution of genomic binary characters in several frameworks, such as for example in haplotype inference. The model, which is conceptually the simplest, is based on the infinite sites assumption, that is no character can mutate more than once in the whole tree. A main open problem regarding the model is finding generalizations that retain the computational tractability of the original model but are more flexible in modeling biological data when the infinite site assumption is violated because of e.g. back mutations. A special case of back mutations that has been considered in the study of the evolution of protein domains (where a domain is acquired and then lost) is persistency, that is the fact that a character is allowed to return back to the ancestral state. In this model characters can be gained and lost at most once. In this paper we consider the computational problem of explaining binary data by the Persistent Perfect Phylogeny model (referred as PPP) and for this purpose we investigate the problem of reconstructing an evolution where some constraints are imposed on the paths of the tree. Results We define a natural generalization of the PPP problem obtained by requiring that for some pairs (character, species), neither the species nor any of its ancestors can have the character. In other words, some characters cannot be persistent for some species. This new problem is called Constrained PPP (CPPP). Based on a graph formulation of the CPPP problem, we are able to provide a polynomial time solution for the CPPP problem for matrices whose conflict graph has no edges. Using this result, we develop a parameterized algorithm for solving the CPPP problem where the parameter is the number of characters. Conclusions A preliminary experimental analysis shows that the constrained persistent perfect phylogeny model allows to

  11. Molecular analyses on host-seeking black flies (Diptera: Simuliidae) reveal a diverse assemblage of Leucocytozoon (Apicomplexa: Haemospororida) parasites in an alpine ecosystem.

    PubMed

    Murdock, Courtney C; Adler, Peter H; Frank, Jared; Perkins, Susan L

    2015-06-25

    Molecular studies have suggested that the true diversity of Leucocytozoon (Apicomplexa: Haemospororida) species well exceeds the approximately 35 currently described taxa. Further, the degree of host-specificity may vary substantially among lineages. Parasite distribution can be influenced by the ability of the parasite to infect a host, vector preferences for certain avian hosts, or other factors such as microhabitat requirements that increase the probability that vertebrate hosts and vectors are in frequent contact with each other. Whereas most studies of haemosporidians have focused on passerine hosts, sampling vectors in the same habitats may allow the detection of other lineages affecting other hosts. We sampled abundant, ornithophilic black flies (Simuliidae) across a variety of sites and habitats in the Colorado Rocky Mountains throughout the summer of 2007. Black flies were screened with PCR using Leucocytozoon-specific primers that amplify a portion of the cytochrome b gene, and the sequences were compared to the haplotypes in the MalAvi database. Infections of Leucocytozoon from birds sampled in the same area were also included. We recovered 33 unique haplotypes from the black flies in this study area, which represented a large phylogenetic diversity of Leucocytozoon parasites. However, there were no clear patterns of avian host species or geography for the distribution of Leucocytozoon haplotypes in the phylogeny. Sampling host-seeking vectors is a useful way to obtain a wide variety of avian haemosporidian haplotypes from a given area and may prove useful for understanding the global patterns of host, parasite, and vector associations of these ubiquitous and diverse parasites.

  12. DNA barcoding and phylogeny of Calidris and Tringa (Aves: Scolopacidae).

    PubMed

    Huang, Zuhao; Tu, Feiyun

    2017-07-01

    The avian genera Calidris and Tringa are the largest of the widespread family of Scolopacidae. The phylogeny of members of the two genera is still a matter of controversial. Mitochondrial cytochrome c oxidase subunit I (COI) can serve as a fast and accurate marker for the identification and phylogeny of animal species. In this study, we analyzed the COI barcodes of thirty-one species of the two genera. All the species had distinct COI sequences. Two hundred and twenty-one variable sites were identified. Kimura two-parameter distances were calculated between barcodes. Neighbor-joining and maximum likelihood methods were used to construct phylogenetic trees. All the species could be discriminated by their distinct clades in the phylogenetic trees. The phylogenetic trees grouped all the species of Calidris and Tringa into different monophyletic clade, respectively. COI data showed a well-supported phylogeny for Calidris and Tringa species.

  13. A Molecular Phylogeny of Living Primates

    PubMed Central

    Perelman, Polina; Johnson, Warren E.; Roos, Christian; Seuánez, Hector N.; Horvath, Julie E.; Moreira, Miguel A. M.; Kessing, Bailey; Pontius, Joan; Roelke, Melody; Rumpler, Yves; Schneider, Maria Paula C.; Silva, Artur; O'Brien, Stephen J.; Pecon-Slattery, Jill

    2011-01-01

    Comparative genomic analyses of primates offer considerable potential to define and understand the processes that mold, shape, and transform the human genome. However, primate taxonomy is both complex and controversial, with marginal unifying consensus of the evolutionary hierarchy of extant primate species. Here we provide new genomic sequence (∼8 Mb) from 186 primates representing 61 (∼90%) of the described genera, and we include outgroup species from Dermoptera, Scandentia, and Lagomorpha. The resultant phylogeny is exceptionally robust and illuminates events in primate evolution from ancient to recent, clarifying numerous taxonomic controversies and providing new data on human evolution. Ongoing speciation, reticulate evolution, ancient relic lineages, unequal rates of evolution, and disparate distributions of insertions/deletions among the reconstructed primate lineages are uncovered. Our resolution of the primate phylogeny provides an essential evolutionary framework with far-reaching applications including: human selection and adaptation, global emergence of zoonotic diseases, mammalian comparative genomics, primate taxonomy, and conservation of endangered species. PMID:21436896

  14. Displaced phylogeographic signals from Gyrodactylus arcuatus, a parasite of the three-spined stickleback Gasterosteus aculeatus, suggest freshwater glacial refugia in Europe

    USGS Publications Warehouse

    Lumme, Jaakko; Mäkinen, Hannu; Ermolenko, Alexey V.; Gregg, Jacob L.; Ziętara, Marek S.

    2016-01-01

    We examined the global mitochondrial phylogeography of Gyrodactylus arcuatus, a flatworm ectoparasite of three-spined stickleback Gasterosteus aculeatus. In accordance with the suggested high divergence rate of 13%/million years, the genetic variation of the parasite was high: haplotype diversity h = 0.985 and nucleotide diversity π = 0.0161. The differentiation among the parasite populations was substantial (Φst = 0.759), with two main allopatric clades (here termed Euro and North) accounting for 54% of the total genetic variation. The diversity center of the Euro clade was in the Baltic Sea, while the North clade was spread across the Barents and White Seas. A single haplotype within the North clade was found in the western and eastern Pacific Ocean. Divergence of main clades was estimated to be circa 200 thousand years ago. Each main clade was further divided into six distinct subclades, estimated to have diverged in isolation since 135 thousand years ago. This second division corresponds approximately to the Eemian interglacial predating the last glacial maximum. A demographic expansion of the subclades is associated with colonisation of northern Europe since the last glacial maximum, circa 15–40 thousand years ago. The parasite phylogeny is most likely explained by sequential isolated bottlenecks and expansions in numerous allopatric refugia. The postglacial intermingling and high variation in the marine parasite populations, separately in the Baltic and Barents Seas, suggest low competition of divergent parasite matrilines, coupled with a large population size and high rate of dispersal of hosts. The genetic contribution of the assumed refugial fish populations maintaining the parasite during the last glacial maximum was not detected among the marine sticklebacks, which perhaps were infected after range expansion.

  15. Displaced phylogeographic signals from Gyrodactylus arcuatus, a parasite of the three-spined stickleback Gasterosteus aculeatus, suggest freshwater glacial refugia in Europe.

    PubMed

    Lumme, Jaakko; Mäkinen, Hannu; Ermolenko, Alexey V; Gregg, Jacob L; Ziętara, Marek S

    2016-08-01

    We examined the global mitochondrial phylogeography of Gyrodactylus arcuatus, a flatworm ectoparasite of three-spined stickleback Gasterosteus aculeatus. In accordance with the suggested high divergence rate of 13%/million years, the genetic variation of the parasite was high: haplotype diversity h=0.985 and nucleotide diversity π=0.0161. The differentiation among the parasite populations was substantial (Φst=0.759), with two main allopatric clades (here termed Euro and North) accounting for 54% of the total genetic variation. The diversity center of the Euro clade was in the Baltic Sea, while the North clade was spread across the Barents and White Seas. A single haplotype within the North clade was found in the western and eastern Pacific Ocean. Divergence of main clades was estimated to be circa 200 thousand years ago. Each main clade was further divided into six distinct subclades, estimated to have diverged in isolation since 135 thousand years ago. This second division corresponds approximately to the Eemian interglacial predating the last glacial maximum. A demographic expansion of the subclades is associated with colonisation of northern Europe since the last glacial maximum, circa 15-40 thousand years ago. The parasite phylogeny is most likely explained by sequential isolated bottlenecks and expansions in numerous allopatric refugia. The postglacial intermingling and high variation in the marine parasite populations, separately in the Baltic and Barents Seas, suggest low competition of divergent parasite matrilines, coupled with a large population size and high rate of dispersal of hosts. The genetic contribution of the assumed refugial fish populations maintaining the parasite during the last glacial maximum was not detected among the marine sticklebacks, which perhaps were infected after range expansion. Copyright © 2016 Australian Society for Parasitology. All rights reserved.

  16. Catenotaenia dendritica (Cestoda: Catenotaeniidae) and Three Ectoparasite Species in the Red Squirrel, Sciurus vulgaris, from Cheongju, Korea

    PubMed Central

    Choe, Seongjun; Lee, Dongmin; Park, Hansol; Jeon, Hyeong-Kyu; Lee, Youngsun; Na, Ki-Jeong; Lee, In-Yong; Eom, Keeseon S.

    2016-01-01

    Parasites are recorded from the red squirrel, Sciurus vulgaris, from Cheongju, the Republic of Korea. A total of 5 road-killed squirrels were thoroughly examined for internal and external parasites from November 2011 to May 2014. Total 4 parasite species, including 1 tapeworm and 3 ectoparasite species were recovered. They were morphologically identified as Catenotaenia dendritica (Cestoda: Catenotaeniidae), Hirstionyssus sciurinus, Leptotrombidium pallidum, and Ceratophyllus (Monopsyllus) indages. Among them, C. dendritica and H. sciurinus are recorded for the first time in the Korean parasite fauna. In addition, the possibility that the red squirrel could act as a reservoir host for a zoonotic disease like tsutsugamushi disease with L. pallidum as its vector has been raised. PMID:27658604

  17. Catenotaenia dendritica (Cestoda: Catenotaeniidae) and Three Ectoparasite Species in the Red Squirrel, Sciurus vulgaris, from Cheongju, Korea.

    PubMed

    Choe, Seongjun; Lee, Dongmin; Park, Hansol; Jeon, Hyeong-Kyu; Lee, Youngsun; Na, Ki-Jeong; Lee, In-Yong; Eom, Keeseon S

    2016-08-01

    Parasites are recorded from the red squirrel, Sciurus vulgaris, from Cheongju, the Republic of Korea. A total of 5 road-killed squirrels were thoroughly examined for internal and external parasites from November 2011 to May 2014. Total 4 parasite species, including 1 tapeworm and 3 ectoparasite species were recovered. They were morphologically identified as Catenotaenia dendritica (Cestoda: Catenotaeniidae), Hirstionyssus sciurinus, Leptotrombidium pallidum, and Ceratophyllus (Monopsyllus) indages. Among them, C. dendritica and H. sciurinus are recorded for the first time in the Korean parasite fauna. In addition, the possibility that the red squirrel could act as a reservoir host for a zoonotic disease like tsutsugamushi disease with L. pallidum as its vector has been raised.

  18. Molecular phylogeny and morphological change in the Psittacula parakeets.

    PubMed

    Groombridge, Jim J; Jones, Carl G; Nichols, Richard A; Carlton, Mark; Bruford, Michael W

    2004-04-01

    We reconstruct a phylogeny of the African and Asian Psittacula parakeets using approximately 800bp of mitochondrial cytochrome b sequence to examine their evolutionary relationships in reference to their head plumage and major morphological tail innovations. Our phylogeny identifies three groups, whose distinctiveness is also apparent from their possession of three different head plumage characters: a neck ring, a distinctive colouration of the head, and a 'moustache'-shaped pattern that extends from the chin to the cheek. We examine the extent of sexual dimorphism in tail length across the phylogeny and reveal large differences between closely related forms. We apply a range of published avian cytochrome b substitution rates to our data, as an alternative to internal calibration of a molecular clock arising from incomplete paleontological information. An ancestral Psittacula form appears to have evolved during the late Miocene-early Pliocene (3.4-9.7MYA), a time when regional geological processes on the Asian continent may have promoted subsequent diversity at the species level, and many forms diverged relatively early on in the evolutionary history of Psittacula (between 2.5 and 7.7MYA). However, others, such as the derbyan and moustached parakeets, diverged as recently as 0.2MYA. Our phylogeny also suggests that the echo parakeet from Mauritius diverged from the Indian ringneck parakeet as opposed to the African ringneck, and may have done so relatively recently. The molecular results indicate support for a southwards radiation from India across the Indian Ocean to Mauritius, where the arrival-date of the echo parakeet appears consistent with the island's volcanic formation.

  19. A well-resolved phylogeny of the trees of Puerto Rico based on DNA barcode sequence data.

    PubMed

    Muscarella, Robert; Uriarte, María; Erickson, David L; Swenson, Nathan G; Zimmerman, Jess K; Kress, W John

    2014-01-01

    The use of phylogenetic information in community ecology and conservation has grown in recent years. Two key issues for community phylogenetics studies, however, are (i) low terminal phylogenetic resolution and (ii) arbitrarily defined species pools. We used three DNA barcodes (plastid DNA regions rbcL, matK, and trnH-psbA) to infer a phylogeny for 527 native and naturalized trees of Puerto Rico, representing the vast majority of the entire tree flora of the island (89%). We used a maximum likelihood (ML) approach with and without a constraint tree that enforced monophyly of recognized plant orders. Based on 50% consensus trees, the ML analyses improved phylogenetic resolution relative to a comparable phylogeny generated with Phylomatic (proportion of internal nodes resolved: constrained ML = 74%, unconstrained ML = 68%, Phylomatic = 52%). We quantified the phylogenetic composition of 15 protected forests in Puerto Rico using the constrained ML and Phylomatic phylogenies. We found some evidence that tree communities in areas of high water stress were relatively phylogenetically clustered. Reducing the scale at which the species pool was defined (from island to soil types) changed some of our results depending on which phylogeny (ML vs. Phylomatic) was used. Overall, the increased terminal resolution provided by the ML phylogeny revealed additional patterns that were not observed with a less-resolved phylogeny. With the DNA barcode phylogeny presented here (based on an island-wide species pool), we show that a more fully resolved phylogeny increases power to detect nonrandom patterns of community composition in several Puerto Rican tree communities. Especially if combined with additional information on species functional traits and geographic distributions, this phylogeny will (i) facilitate stronger inferences about the role of historical processes in governing the assembly and composition of Puerto Rican forests, (ii) provide insight into Caribbean

  20. Phylogeny mandalas of birds using the lithographs of John Gould's folio bird books.

    PubMed

    Hasegawa, Masami; Kuroda, Sayako

    2017-12-01

    The phylogeny mandala, which is a circular phylogeny with photos or drawings of species, is a suitable way to show visually how the biodiversity has developed in the course of evolution as clarified by the molecular phylogenetics. In this article, in order to demonstrate the recent progress of avian molecular phylogenetics, six phylogeny mandalas of various taxonomic groups of birds are presented with the lithographs of John Gould's folio bird books; i.e., (1) whole Aves, (2) Passeriformes, (3) Paradisaeidae in Corvoidea (Passeriformes), (4) Meliphagoidea (Passeriformes), (5) Trochili in Apodiformes, and (6) Galliformes. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. 77 FR 4225 - Oral Dosage Form New Animal Drugs; Milbemycin Oxime, Lufenuron, and Praziquantel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-27

    ... control of fleas, and for the treatment and control of various internal parasites in dogs. DATES: This... and control of adult roundworm, adult hookworm, adult whipworm, and adult tapeworm infections in dogs...) Sponsor. See No. 058198 in Sec. 510.600(c) of this chapter. (c) [Reserved] (d) Conditions of use--(1) Dogs...

  2. Taxonomic and phytogeographic implications from ITS phylogeny in Berberis (Berberidaceae).

    PubMed

    Kim, Young-Dong; Kim, Sung-Hee; Landrum, Leslie R

    2004-06-01

    A phylogeny based on the internal transcribed spacer (ITS) sequences from 79 taxa representing much of the diversity of Berberis L. (four major groups and 22 sections) was constructed for the first time. The phylogeny was basically congruent with the previous classification schemes at higher taxonomic levels, such as groups and subgroups. A notable exception is the non-monophyly of the group Occidentales of compound-leaved Berberis (previously separated as Mahonia). At lower levels, however, most of previous sections and subsections were not evident especially in simple-leaved Berberis. Possible relationship between section Horridae (group Occidentales) and the simple-leaved Berberis clade implies paraphyly of the compound-leaved Berberis. A well-known South America-Old World (mainly Asia) disjunctive distribution pattern of the simple-leaved Berberis is explained by a vicariance event occurring in the Cretaceous period. The ITS phylogeny also suggests that a possible connection between the Asian and South American groups through the North American species ( Berberis canadensis or B. fendleri) is highly unlikely.

  3. When parasites become prey: ecological and epidemiological significance of eating parasites

    USGS Publications Warehouse

    Johnson, Pieter T.J.; Dobson, Andrew P.; Lafferty, Kevin D.; Marcogliese, David J.; Memmott, Jane; Orlofske, Sarah A.; Poulin, Robert; Thieltges, David W.

    2010-01-01

    Recent efforts to include parasites in food webs have drawn attention to a previously ignored facet of foraging ecology: parasites commonly function as prey within ecosystems. Because of the high productivity of parasites, their unique nutritional composition and their pathogenicity in hosts, their consumption affects both food-web topology and disease risk in humans and wildlife. Here, we evaluate the ecological, evolutionary and epidemiological significance of feeding on parasites, including concomitant predation, grooming, predation on free-living stages and intraguild predation. Combining empirical data and theoretical models, we show that consumption of parasites is neither rare nor accidental, and that it can sharply affect parasite transmission and food web properties. Broader consideration of predation on parasites will enhance our understanding of disease control, food web structure and energy transfer, and the evolution of complex life cycles.

  4. Molecular phylogeny and character evolution in terete-stemmed Andean opuntias (Cactaceae-Opuntioideae).

    PubMed

    Ritz, C M; Reiker, J; Charles, G; Hoxey, P; Hunt, D; Lowry, M; Stuppy, W; Taylor, N

    2012-11-01

    The cacti of tribe Tephrocacteae (Cactaceae-Opuntioideae) are adapted to diverse climatic conditions over a wide area of the southern Andes and adjacent lowlands. They exhibit a range of life forms from geophytes and cushion-plants to dwarf shrubs, shrubs or small trees. To confirm or challenge previous morphology-based classifications and molecular phylogenies, we sampled DNA sequences from the chloroplast trnK/matK region and the nuclear low copy gene phyC and compared the resulting phylogenies with previous data gathered from nuclear ribosomal DNA sequences. The here presented chloroplast and nuclear low copy gene phylogenies were mutually congruent and broadly coincident with the classification based on gross morphology and seed micro-morphology and anatomy. Reconstruction of hypothetical ancestral character states suggested that geophytes and cushion-forming species probably evolved several times from dwarf shrubby precursors. We also traced an increase of embryo size at the expense of the nucellus-derived storage tissue during the evolution of the Tephrocacteae, which is thought to be an evolutionary advantage because nutrients are then more rapidly accessible for the germinating embryo. In contrast to these highly concordant phylogenies, nuclear ribosomal DNA data sampled by a previous study yielded conflicting phylogenetic signals. Secondary structure predictions of ribosomal transcribed spacers suggested that this phylogeny is strongly influenced by the inclusion of paralogous sequence probably arisen by genome duplication during the evolution of this plant group. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Parasites that cause problems in Malaysia: soil-transmitted helminths and malaria parasites.

    PubMed

    Singh, B; Cox-Singh, J

    2001-12-01

    Malaysia is a developing country with a range of parasitic infections. Indeed, soil-transmitted helminths and malaria parasites continue to have a significant impact on public health in Malaysia. In this article, the prevalence and distribution of these parasites, the problems associated with parasitic infections, the control measures taken to deal with these parasites and implications for the future will be discussed.

  6. [Assessment of the quality of laboratory diagnosis of intestinal parasitic diseases by the laboratories participating in the Federal System of External Quality Assessment of Clinical Laboratory Testing].

    PubMed

    Malakhov, V N; Dovgalev, A S; Astanina, S Iu; Serdiuk, A P

    2014-01-01

    In 2010-2013, the quality of microscopic detection of the causative agents ofparasitic diseases in the feces has been assessed by the specialists of the laboratories of the therapeutic-and-prophylactic institutions (TPIs) and Hygiene and Epidemiology Centers, Russian Inspectorate for the Protection of Consumer Rights and Human Welfare, which are participants of the Federal System of External Quality Assessment of Clinical Laboratory Testing. Thirty-two specimens containing 16 species of human helminths and 4 species of enteric protozoa in different combinations were examined. The findings suggest that the quality of microscopic detection of the causative agents of parasitic diseases is low in the laboratories of health care facilities and that the specialists of the laboratories of TPIs and Hygiene and Epidemiology Centers, Russian Inspectorate for the Protection of Consumer Rights and Human Welfare, do not not possess the knowledge and skills necessary to make a laboratory diagnosis of helminths and enteric protozoa. The average detection rates of helminths and protozoa were at a level of 64 and 36%, respectively. The correct results showed that the proportion of helminths and protozoa were 94.5 and 5.5%, respectively. According to the biological and epidemiological classification of helminths, there were higher detection rates for contact group parasites (Enterobius vermicularis and Hymenolepis nana) and geohelminths (Ascaris, Trichuris trichiura, and others). Biohelminths (Opisthorchis, tapeworms, and others) Were detectable slightly worse.

  7. Genus-specific PCR Primers Targeting Intracellular Parasite Euduboscquella (Dinoflagellata: Syndinea)

    NASA Astrophysics Data System (ADS)

    Jung, Jae-Ho; Choi, Jung Min; Kim, Young-Ok

    2018-03-01

    We designed a genus-specific primer pair targeting the intracellular parasite Euduboscquella. To increase target specificity and inhibit untargeted PCR, two nucleotides were added at the 3' end of the reverse primer, one being a complementary nucleotide to the Euduboscquella-specific SNP (single-nucleotide polymorphism) and the other a deliberately mismatched nucleotide. Target specificity of the primer set was verified experimentally using PCR of two Euduboscquella species (positive controls) and 15 related species (negative controls composed of ciliates, diatoms and dinoflagellates), and analytical comparison with SILVA SSU rRNA gene database (release 119) in silico. In addition, we applied the Euduboscquella-specific primer set to four environmental samples previously determined by cytological staining to be either positive or negative for Euduboscquella. As expected, only positive controls and environmental samples known to contain Euduboscquella were successfully amplified by the primer set. An inferred SSU rRNA gene phylogeny placed environmental samples containing aloricate ciliates infected by Euduboscquella in a cluster discrete from Euduboscquella groups a-d previously reported from loricate, tintinnid ciliates.

  8. The tapeworm Atractolytocestus tenuicollis (Cestoda: Caryophyllidea)--a sister species or ancestor of an invasive A. huronensis?

    PubMed

    Králová-Hromadová, Ivica; Štefka, Jan; Bazsalovicsová, Eva; Bokorová, Silvia; Oros, Mikuláš

    2013-10-01

    Atractolytocestus tenuicollis (Li, 1964) Xi, Wang, Wu, Gao et Nie, 2009 is a monozoic, non-segmented tapeworm of the order Caryophyllidea, parasitizing exclusively common carp (Cyprinus carpio L.). In the current work, the first molecular data, in particular complete ribosomal internal transcribed spacer 2 (ITS2) and partial mitochondrial cytochrome c oxidase subunit I (cox1) on A. tenuicollis from Niushan Lake, Wuhan, China, are provided. In order to evaluate molecular interrelationships within Atractolytocestus, the data on A. tenuicollis were compared with relevant data on two other congeners, Atractolytocestus huronensis and Atractolytocestus sagittatus. Divergent intragenomic copies (ITS2 paralogues) were detected in the ITS2 ribosomal spacer of A. tenuicollis; the same phenomenon has previously been observed also in two other congeners. ITS2 structure of A. tenuicollis was very similar to that of A. huronensis from Slovakia, USA and UK; overall pairwise sequence identity was 91.7-95.2%. On the other hand, values of sequence identity between A. tenuicollis and A. sagittatus were lower, 69.7-70.9%. Cox1 sequence, analysed in five A. tenuicollis individuals, were 100 % identical and no intraspecific variation was observed. Comparison of A. tenuicollis cox1 with respective sequences of two other Atractolytocestus species showed that the mitochondrial haplotype found in Chinese A. tenuicollis is structurally specific (haplotype 4; Ha4) and differs from all so far determined Atractolytocestus haplotypes (Ha1 and Ha2 for A. huronensis; Ha3 for A. sagittatus). Pairwise sequence identity between A. tenuicollis cox1 haplotype and remaining three haplotypes followed the same pattern as in ITS2. The nucleotide and amino acide (aa) sequence comparison with A. huronensis Ha1 and Ha2 revealed higher sequence identity, 90.3-90.8% (96.9% in aa), while lower values were achieved between A. tenuicollis haplotype and Ha3 of Japanese A. sagittatus-75.2 % (81.9 % in aa). The

  9. Developmental Stage of Parasites Influences the Structure of Fish-Parasite Networks

    PubMed Central

    Bellay, Sybelle; de Oliveira, Edson Fontes; Almeida-Neto, Mário; Lima Junior, Dilermando Pereira; Takemoto, Ricardo Massato; Luque, José Luis

    2013-01-01

    Specialized interactions tend to be more common in systems that require strong reciprocal adaptation between species, such as those observed between parasites and hosts. Parasites exhibit a high diversity of species and life history strategies, presenting host specificity which increases the complexity of these antagonistic systems. However, most studies are limited to the description of interactions between a few parasite and host species, which restricts our understanding of these systems as a whole. We investigated the effect of the developmental stage of the parasite on the structure of 30 metazoan fish-parasite networks, with an emphasis on the specificity of the interactions, connectance and modularity. We assessed the functional role of each species in modular networks and its interactions within and among the modules according to the developmental stage (larval and adult) and taxonomic group of the parasites. We observed that most parasite and host species perform a few interactions but that parasites at the larval stage tended to be generalists, increasing the network connectivity within and among modules. The parasite groups did not differ among each other in the number of interactions within and among the modules when considering only species at the larval stage. However, the same groups of adult individuals differed from each other in their interaction patterns, which were related to variations in the degree of host specificity at this stage. Our results show that the interaction pattern of fishes with parasites, such as acanthocephalans, cestodes, digeneans and nematodes, is more closely associated with their developmental stage than their phylogenetic history. This finding corroborates the hypothesis that the life history of parasites results in adaptations that cross phylogenetic boundaries. PMID:24124506

  10. Developmental stage of parasites influences the structure of fish-parasite networks.

    PubMed

    Bellay, Sybelle; de Oliveira, Edson Fontes; Almeida-Neto, Mário; Lima Junior, Dilermando Pereira; Takemoto, Ricardo Massato; Luque, José Luis

    2013-01-01

    Specialized interactions tend to be more common in systems that require strong reciprocal adaptation between species, such as those observed between parasites and hosts. Parasites exhibit a high diversity of species and life history strategies, presenting host specificity which increases the complexity of these antagonistic systems. However, most studies are limited to the description of interactions between a few parasite and host species, which restricts our understanding of these systems as a whole. We investigated the effect of the developmental stage of the parasite on the structure of 30 metazoan fish-parasite networks, with an emphasis on the specificity of the interactions, connectance and modularity. We assessed the functional role of each species in modular networks and its interactions within and among the modules according to the developmental stage (larval and adult) and taxonomic group of the parasites. We observed that most parasite and host species perform a few interactions but that parasites at the larval stage tended to be generalists, increasing the network connectivity within and among modules. The parasite groups did not differ among each other in the number of interactions within and among the modules when considering only species at the larval stage. However, the same groups of adult individuals differed from each other in their interaction patterns, which were related to variations in the degree of host specificity at this stage. Our results show that the interaction pattern of fishes with parasites, such as acanthocephalans, cestodes, digeneans and nematodes, is more closely associated with their developmental stage than their phylogenetic history. This finding corroborates the hypothesis that the life history of parasites results in adaptations that cross phylogenetic boundaries.

  11. Parasites and cancers: parasite antigens as possible targets for cancer immunotherapy.

    PubMed

    Darani, Hossein Yousofi; Yousefi, Morteza

    2012-12-01

    An adverse relationship between some parasite infections and cancer in the human population has been reported by different research groups. Anticancer activity of some parasites such as Trypanosoma cruzi, Toxoplasma gondii, Toxocara canis, Acantamoeba castellani and Plasmodium yoelii has been shown in experimental animals. Moreover, it has been shown that cancer-associated mucin-type O-glycan compositions are made by parasites, therefore cancers and parasites have common antigens. In this report anticancer activities of some parasites have been reviewed and the possible mechanisms of these actions have also been discussed.

  12. Resolution of ray-finned fish phylogeny and timing of diversification.

    PubMed

    Near, Thomas J; Eytan, Ron I; Dornburg, Alex; Kuhn, Kristen L; Moore, Jon A; Davis, Matthew P; Wainwright, Peter C; Friedman, Matt; Smith, W Leo

    2012-08-21

    Ray-finned fishes make up half of all living vertebrate species. Nearly all ray-finned fishes are teleosts, which include most commercially important fish species, several model organisms for genomics and developmental biology, and the dominant component of marine and freshwater vertebrate faunas. Despite the economic and scientific importance of ray-finned fishes, the lack of a single comprehensive phylogeny with corresponding divergence-time estimates has limited our understanding of the evolution and diversification of this radiation. Our analyses, which use multiple nuclear gene sequences in conjunction with 36 fossil age constraints, result in a well-supported phylogeny of all major ray-finned fish lineages and molecular age estimates that are generally consistent with the fossil record. This phylogeny informs three long-standing problems: specifically identifying elopomorphs (eels and tarpons) as the sister lineage of all other teleosts, providing a unique hypothesis on the radiation of early euteleosts, and offering a promising strategy for resolution of the "bush at the top of the tree" that includes percomorphs and other spiny-finned teleosts. Contrasting our divergence time estimates with studies using a single nuclear gene or whole mitochondrial genomes, we find that the former underestimates ages of the oldest ray-finned fish divergences, but the latter dramatically overestimates ages for derived teleost lineages. Our time-calibrated phylogeny reveals that much of the diversification leading to extant groups of teleosts occurred between the late Mesozoic and early Cenozoic, identifying this period as the "Second Age of Fishes."

  13. Large-scale phylogenomic analysis resolves a backbone phylogeny in ferns.

    PubMed

    Shen, Hui; Jin, Dongmei; Shu, Jiang-Ping; Zhou, Xi-Le; Lei, Ming; Wei, Ran; Shang, Hui; Wei, Hong-Jin; Zhang, Rui; Liu, Li; Gu, Yu-Feng; Zhang, Xian-Chun; Yan, Yue-Hong

    2018-02-01

    Ferns, originated about 360 million years ago, are the sister group of seed plants. Despite the remarkable progress in our understanding of fern phylogeny, with conflicting molecular evidence and different morphological interpretations, relationships among major fern lineages remain controversial. With the aim to obtain a robust fern phylogeny, we carried out a large-scale phylogenomic analysis using high-quality transcriptome sequencing data, which covered 69 fern species from 38 families and 11 orders. Both coalescent-based and concatenation-based methods were applied to both nucleotide and amino acid sequences in species tree estimation. The resulting topologies are largely congruent with each other, except for the placement of Angiopteris fokiensis, Cheiropleuria bicuspis, Diplaziopsis brunoniana, Matteuccia struthiopteris, Elaphoglossum mcclurei, and Tectaria subpedata. Our result confirmed that Equisetales is sister to the rest of ferns, and Dennstaedtiaceae is sister to eupolypods. Moreover, our result strongly supported some relationships different from the current view of fern phylogeny, including that Marattiaceae may be sister to the monophyletic clade of Psilotaceae and Ophioglossaceae; that Gleicheniaceae and Hymenophyllaceae form a monophyletic clade sister to Dipteridaceae; and that Aspleniaceae is sister to the rest of the groups in eupolypods II. These results were interpreted with morphological traits, especially sporangia characters, and a new evolutionary route of sporangial annulus in ferns was suggested. This backbone phylogeny in ferns sets a foundation for further studies in biology and evolution in ferns, and therefore in plants. © The Authors 2017. Published by Oxford University Press.

  14. Large-scale phylogenomic analysis resolves a backbone phylogeny in ferns

    PubMed Central

    Shen, Hui; Jin, Dongmei; Shu, Jiang-Ping; Zhou, Xi-Le; Lei, Ming; Wei, Ran; Shang, Hui; Wei, Hong-Jin; Zhang, Rui; Liu, Li; Gu, Yu-Feng; Zhang, Xian-Chun; Yan, Yue-Hong

    2018-01-01

    Abstract Background Ferns, originated about 360 million years ago, are the sister group of seed plants. Despite the remarkable progress in our understanding of fern phylogeny, with conflicting molecular evidence and different morphological interpretations, relationships among major fern lineages remain controversial. Results With the aim to obtain a robust fern phylogeny, we carried out a large-scale phylogenomic analysis using high-quality transcriptome sequencing data, which covered 69 fern species from 38 families and 11 orders. Both coalescent-based and concatenation-based methods were applied to both nucleotide and amino acid sequences in species tree estimation. The resulting topologies are largely congruent with each other, except for the placement of Angiopteris fokiensis, Cheiropleuria bicuspis, Diplaziopsis brunoniana, Matteuccia struthiopteris, Elaphoglossum mcclurei, and Tectaria subpedata. Conclusions Our result confirmed that Equisetales is sister to the rest of ferns, and Dennstaedtiaceae is sister to eupolypods. Moreover, our result strongly supported some relationships different from the current view of fern phylogeny, including that Marattiaceae may be sister to the monophyletic clade of Psilotaceae and Ophioglossaceae; that Gleicheniaceae and Hymenophyllaceae form a monophyletic clade sister to Dipteridaceae; and that Aspleniaceae is sister to the rest of the groups in eupolypods II. These results were interpreted with morphological traits, especially sporangia characters, and a new evolutionary route of sporangial annulus in ferns was suggested. This backbone phylogeny in ferns sets a foundation for further studies in biology and evolution in ferns, and therefore in plants. PMID:29186447

  15. Dinoflagellate phylogeny revisited: Using ribosomal proteins to resolve deep branching dinoflagellate clades

    PubMed Central

    Bachvaroff, Tsvetan R.; Gornik, Sebastian G.; Concepcion, Gregory T.; Waller, Ross F.; Mendez, Gregory S.; Lippmeier, J. Casey; Delwiche, Charles F.

    2014-01-01

    The alveolates are composed of three major lineages, the ciliates, dinoflagellates, and apicomplexans. Together these ‘protist’ taxa play key roles in primary production and ecology, as well as in illness of humans and other animals. The interface between the dinoflagellate and apicomplexan clades has been an area of recent discovery, blurring the distinction between these two clades. Moreover, phylogenetic analysis has yet to determine the position of basal dinoflagellate clades hence the deepest branches of the dinoflagellate tree currently remain unresolved. Large-scale mRNA sequencing was applied to 11 species of dinoflagellates, including strains of the syndinean genera Hematodinium and Amoebophrya, parasites of crustaceans and dinoflagellates, respectively, to optimize and update the dinoflagellate tree. From the transcriptome-scale data a total of 73 ribosomal protein-coding genes were selected for phylogeny. After individual gene orthology assessment, the genes were concatenated into a >15,000 amino acid alignment with 76 taxa from dinoflagellates, apicomplexans, ciliates, and the outgroup heterokonts. Overall the tree was well resolved and supported, when the data was subsampled with gblocks or constraint trees were tested with the approximately unbiased test. The deepest branches of the dinoflagellate tree can now be resolved with strong support, and provides a clearer view of the evolution of the distinctive traits of dinoflagellates. PMID:24135237

  16. Correcting for sequencing error in maximum likelihood phylogeny inference.

    PubMed

    Kuhner, Mary K; McGill, James

    2014-11-04

    Accurate phylogenies are critical to taxonomy as well as studies of speciation processes and other evolutionary patterns. Accurate branch lengths in phylogenies are critical for dating and rate measurements. Such accuracy may be jeopardized by unacknowledged sequencing error. We use simulated data to test a correction for DNA sequencing error in maximum likelihood phylogeny inference. Over a wide range of data polymorphism and true error rate, we found that correcting for sequencing error improves recovery of the branch lengths, even if the assumed error rate is up to twice the true error rate. Low error rates have little effect on recovery of the topology. When error is high, correction improves topological inference; however, when error is extremely high, using an assumed error rate greater than the true error rate leads to poor recovery of both topology and branch lengths. The error correction approach tested here was proposed in 2004 but has not been widely used, perhaps because researchers do not want to commit to an estimate of the error rate. This study shows that correction with an approximate error rate is generally preferable to ignoring the issue. Copyright © 2014 Kuhner and McGill.

  17. Heavy metal resistant strains are widespread along Streptomyces phylogeny.

    PubMed

    Alvarez, Analía; Catalano, Santiago A; Amoroso, María Julia

    2013-03-01

    The genus Streptomyces comprises a group of bacteria species with high economic importance. Several of these species are employed at industrial scale for the production of useful compounds. Other characteristic found in different strains within this genus is their capability to tolerate high level of substances toxic for humans, heavy metals among them. Although several studies have been conducted in different species of the genus in order to disentangle the mechanisms associated to heavy metal resistance, little is known about how they have evolved along Streptomyces phylogeny. In this study we built the largest Streptomyces phylogeny generated up to date comprising six genes, 113 species of Streptomyces and 27 outgroups. The parsimony-based phylogenetic analysis indicated that (i) Streptomyces is monophyletic and (ii) it appears as sister clade of a group formed by Kitasatospora and Streptacidiphilus species, both genera also monophyletic. Streptomyces strains resistant to heavy metals are not confined to a single lineage but widespread along Streptomyces phylogeny. Our result in combination with genomic, physiological and biochemical data suggest that the resistance to heavy metals originated several times and by different mechanisms in Streptomyces history. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Phylogeny of metabolic networks: a spectral graph theoretical approach.

    PubMed

    Deyasi, Krishanu; Banerjee, Anirban; Deb, Bony

    2015-10-01

    Many methods have been developed for finding the commonalities between different organisms in order to study their phylogeny. The structure of metabolic networks also reveals valuable insights into metabolic capacity of species as well as into the habitats where they have evolved. We constructed metabolic networks of 79 fully sequenced organisms and compared their architectures. We used spectral density of normalized Laplacian matrix for comparing the structure of networks. The eigenvalues of this matrix reflect not only the global architecture of a network but also the local topologies that are produced by different graph evolutionary processes like motif duplication or joining. A divergence measure on spectral densities is used to quantify the distances between various metabolic networks, and a split network is constructed to analyse the phylogeny from these distances. In our analysis, we focused on the species that belong to different classes, but appear more related to each other in the phylogeny. We tried to explore whether they have evolved under similar environmental conditions or have similar life histories. With this focus, we have obtained interesting insights into the phylogenetic commonality between different organisms.

  19. Description of the first cryptic avian malaria parasite, Plasmodium homocircumflexum n. sp., with experimental data on its virulence and development in avian hosts and mosquitoes.

    PubMed

    Palinauskas, Vaidas; Žiegytė, Rita; Ilgūnas, Mikas; Iezhova, Tatjana A; Bernotienė, Rasa; Bolshakov, Casimir; Valkiūnas, Gediminas

    2015-01-01

    For over 100 years studies on avian haemosporidian parasite species have relied on similarities in their morphology to establish a species concept. Some exceptional cases have also included information about the life cycle and sporogonic development. More than 50 avian Plasmodium spp. have now been described. However, PCR-based studies show a much broader diversity of haemosporidian parasites, indicating the possible existence of a diverse group of cryptic species. In the present study, using both similarity and phylogenetic species definition concepts, we believe that we report the first characterised cryptic speciation case of an avian Plasmodium parasite. We used sequence information on the mitochondrial cytochrome b gene and constructed phylogenies of identified Plasmodium spp. to define their position in the phylogenetic tree. After analysis of blood stages, the morphology of the parasite was shown to be identical to Plasmodium circumflexum. However, the geographic distribution of the new parasite, the phylogenetic information, as well as patterns of development of infection, indicate that this parasite differs from P. circumflexum. Plasmodium homocircumflexum n. sp. was described based on information about genetic differences from described lineages, phylogenetic position and biological characters. This parasite develops parasitemia in experimentally infected birds - the domestic canary Serinus canaria domestica, siskin Carduelis spinus and crossbill Loxia curvirostra. Anaemia caused by high parasitemia, as well as cerebral paralysis caused by exoerythrocytic stages in the brain, are the main reasons for mortality. Exoerythrocytic stages also form in other organs (heart, kidneys, liver, lungs, spleen, intestines and pectoral muscles). DNA amplification was unsuccessful from faecal samples of heavily infected birds. The sporogonic development initiates, but is abortive, at the oocyst stage in two common European mosquito species, Culex pipiens pipiens (forms

  20. A Well-Resolved Phylogeny of the Trees of Puerto Rico Based on DNA Barcode Sequence Data

    PubMed Central

    Muscarella, Robert; Uriarte, María; Erickson, David L.; Swenson, Nathan G.; Zimmerman, Jess K.; Kress, W. John

    2014-01-01

    Background The use of phylogenetic information in community ecology and conservation has grown in recent years. Two key issues for community phylogenetics studies, however, are (i) low terminal phylogenetic resolution and (ii) arbitrarily defined species pools. Methodology/principal findings We used three DNA barcodes (plastid DNA regions rbcL, matK, and trnH-psbA) to infer a phylogeny for 527 native and naturalized trees of Puerto Rico, representing the vast majority of the entire tree flora of the island (89%). We used a maximum likelihood (ML) approach with and without a constraint tree that enforced monophyly of recognized plant orders. Based on 50% consensus trees, the ML analyses improved phylogenetic resolution relative to a comparable phylogeny generated with Phylomatic (proportion of internal nodes resolved: constrained ML = 74%, unconstrained ML = 68%, Phylomatic = 52%). We quantified the phylogenetic composition of 15 protected forests in Puerto Rico using the constrained ML and Phylomatic phylogenies. We found some evidence that tree communities in areas of high water stress were relatively phylogenetically clustered. Reducing the scale at which the species pool was defined (from island to soil types) changed some of our results depending on which phylogeny (ML vs. Phylomatic) was used. Overall, the increased terminal resolution provided by the ML phylogeny revealed additional patterns that were not observed with a less-resolved phylogeny. Conclusions/significance With the DNA barcode phylogeny presented here (based on an island-wide species pool), we show that a more fully resolved phylogeny increases power to detect nonrandom patterns of community composition in several Puerto Rican tree communities. Especially if combined with additional information on species functional traits and geographic distributions, this phylogeny will (i) facilitate stronger inferences about the role of historical processes in governing the assembly and

  1. Taxonomic triage and the poverty of phylogeny.

    PubMed Central

    Wheeler, Quentin D

    2004-01-01

    Revisionary taxonomy is frequently dismissed as merely descriptive, which belies its strong intellectual content and hypothesis-driven nature. Funding for taxonomy is inadequate and largely diverted to studies of phylogeny that neither improve classifications nor nomenclature. Phylogenetic classifications are optimal for storing and predicting information, but phylogeny divorced from taxonomy is ephemeral and erodes the accuracy and information content of the language of biology. Taxonomic revisions and monographs are efficient, high-throughput species hypothesis-testing devices that are ideal for the World Wide Web. Taxonomic knowledge remains essential to credible biological research and is made urgent by the biodiversity crisis. Theoretical and technological advances and threats of mass species extinctions indicate that this is the time for a renaissance in taxonomy. Clarity of vision and courage of purpose are needed from individual taxonomists and natural history museums to bring about this evolution of taxonomy into the information age. PMID:15253345

  2. Fishing drives declines in fish parasite diversity and has variable effects on parasite abundance.

    PubMed

    Wood, Chelsea L; Sandin, Stuart A; Zgliczynski, Brian; Guerra, Ana Sofía; Micheli, Fiorenza

    2014-07-01

    Despite the ubiquity and ecological importance of parasites, relatively few studies have assessed their response to anthropogenic environmental change. Heuristic models have predicted both increases and decreases in parasite abundance in response to human disturbance, with empirical support for both. However, most studies focus on one or a few selected parasite species. Here, we assess the abundance of parasites of seven species of coral reef fishes collected from three fished and three unfished islands of the Line Islands archipelago in the central equatorial Pacific. Because we chose fish hosts that spanned different trophic levels, taxonomic groups, and body sizes, we were able to compare parasite responses across a broad cross section of the total parasite community in the presence and absence of fishing, a major human impact on marine ecosystems. We found that overall parasite species richness was substantially depressed on fished islands, but that the response of parasite abundance varied among parasite taxa: directly transmitted parasites were significantly more abundant on fished than on unfished islands, while the reverse was true for trophically transmitted parasites. This probably arises because trophically transmitted parasites require multiple host species, some of which are the top predators most sensitive to fishing impacts. The increase in directly transmitted parasites appeared to be due to fishing-driven compensatory increases in the abundance of their hosts. Together, these results provide support for the predictions of both heuristic models, and indicate that the direction of fishing's impact on parasite abundance is mediated by parasite traits, notably parasite transmission strategies.

  3. Paradigms for parasite conservation.

    PubMed

    Dougherty, Eric R; Carlson, Colin J; Bueno, Veronica M; Burgio, Kevin R; Cizauskas, Carrie A; Clements, Christopher F; Seidel, Dana P; Harris, Nyeema C

    2016-08-01

    Parasitic species, which depend directly on host species for their survival, represent a major regulatory force in ecosystems and a significant component of Earth's biodiversity. Yet the negative impacts of parasites observed at the host level have motivated a conservation paradigm of eradication, moving us farther from attainment of taxonomically unbiased conservation goals. Despite a growing body of literature highlighting the importance of parasite-inclusive conservation, most parasite species remain understudied, underfunded, and underappreciated. We argue the protection of parasitic biodiversity requires a paradigm shift in the perception and valuation of their role as consumer species, similar to that of apex predators in the mid-20th century. Beyond recognizing parasites as vital trophic regulators, existing tools available to conservation practitioners should explicitly account for the unique threats facing dependent species. We built upon concepts from epidemiology and economics (e.g., host-density threshold and cost-benefit analysis) to devise novel metrics of margin of error and minimum investment for parasite conservation. We define margin of error as the risk of accidental host extinction from misestimating equilibrium population sizes and predicted oscillations, while minimum investment represents the cost associated with conserving the additional hosts required to maintain viable parasite populations. This framework will aid in the identification of readily conserved parasites that present minimal health risks. To establish parasite conservation, we propose an extension of population viability analysis for host-parasite assemblages to assess extinction risk. In the direst cases, ex situ breeding programs for parasites should be evaluated to maximize success without undermining host protection. Though parasitic species pose a considerable conservation challenge, adaptations to conservation tools will help protect parasite biodiversity in the face of

  4. Deep phylogeny and evolution of sponges (phylum Porifera).

    PubMed

    Wörheide, G; Dohrmann, M; Erpenbeck, D; Larroux, C; Maldonado, M; Voigt, O; Borchiellini, C; Lavrov, D V

    2012-01-01

    Sponges (phylum Porifera) are a diverse taxon of benthic aquatic animals of great ecological, commercial, and biopharmaceutical importance. They are arguably the earliest-branching metazoan taxon, and therefore, they have great significance in the reconstruction of early metazoan evolution. Yet, the phylogeny and systematics of sponges are to some extent still unresolved, and there is an on-going debate about the exact branching pattern of their main clades and their relationships to the other non-bilaterian animals. Here, we review the current state of the deep phylogeny of sponges. Several studies have suggested that sponges are paraphyletic. However, based on recent phylogenomic analyses, we suggest that the phylum Porifera could well be monophyletic, in accordance with cladistic analyses based on morphology. This finding has many implications for the evolutionary interpretation of early animal traits and sponge development. We further review the contribution that mitochondrial genes and genomes have made to sponge phylogenetics and explore the current state of the molecular phylogenies of the four main sponge lineages (Classes), that is, Demospongiae, Hexactinellida, Calcarea, and Homoscleromorpha, in detail. While classical systematic systems are largely congruent with molecular phylogenies in the class Hexactinellida and in certain parts of Demospongiae and Homoscleromorpha, the high degree of incongruence in the class Calcarea still represents a challenge. We highlight future areas of research to fill existing gaps in our knowledge. By reviewing sponge development in an evolutionary and phylogenetic context, we support previous suggestions that sponge larvae share traits and complexity with eumetazoans and that the simple sedentary adult lifestyle of sponges probably reflects some degree of secondary simplification. In summary, while deep sponge phylogenetics has made many advances in the past years, considerable efforts are still required to achieve a

  5. Resolution of ray-finned fish phylogeny and timing of diversification

    PubMed Central

    Near, Thomas J.; Eytan, Ron I.; Dornburg, Alex; Kuhn, Kristen L.; Moore, Jon A.; Davis, Matthew P.; Wainwright, Peter C.; Friedman, Matt; Smith, W. Leo

    2012-01-01

    Ray-finned fishes make up half of all living vertebrate species. Nearly all ray-finned fishes are teleosts, which include most commercially important fish species, several model organisms for genomics and developmental biology, and the dominant component of marine and freshwater vertebrate faunas. Despite the economic and scientific importance of ray-finned fishes, the lack of a single comprehensive phylogeny with corresponding divergence-time estimates has limited our understanding of the evolution and diversification of this radiation. Our analyses, which use multiple nuclear gene sequences in conjunction with 36 fossil age constraints, result in a well-supported phylogeny of all major ray-finned fish lineages and molecular age estimates that are generally consistent with the fossil record. This phylogeny informs three long-standing problems: specifically identifying elopomorphs (eels and tarpons) as the sister lineage of all other teleosts, providing a unique hypothesis on the radiation of early euteleosts, and offering a promising strategy for resolution of the “bush at the top of the tree” that includes percomorphs and other spiny-finned teleosts. Contrasting our divergence time estimates with studies using a single nuclear gene or whole mitochondrial genomes, we find that the former underestimates ages of the oldest ray-finned fish divergences, but the latter dramatically overestimates ages for derived teleost lineages. Our time-calibrated phylogeny reveals that much of the diversification leading to extant groups of teleosts occurred between the late Mesozoic and early Cenozoic, identifying this period as the “Second Age of Fishes.” PMID:22869754

  6. Parasites as prey in aquatic food webs: implications for predator infection and parasite transmission

    USGS Publications Warehouse

    Thieltges, David W.; Amundsen, Per-Arne; Hechinger, Ryan F.; Johnson, Pieter T.J.; Lafferty, Levin D.; Mouritsen, Kim N.; Preston, Daniel L.; Reise, Karsten; Zander, C. Dieter; Poulin, Robert

    2013-01-01

    While the recent inclusion of parasites into food-web studies has highlighted the role of parasites as consumers, there is accumulating evidence that parasites can also serve as prey for predators. Here we investigated empirical patterns of predation on parasites and their relationships with parasite transmission in eight topological food webs representing marine and freshwater ecosystems. Within each food web, we examined links in the typical predator–prey sub web as well as the predator–parasite sub web, i.e. the quadrant of the food web indicating which predators eat parasites. Most predator– parasite links represented ‘concomitant predation’ (consumption and death of a parasite along with the prey/host; 58–72%), followed by ‘trophic transmission’ (predator feeds on infected prey and becomes infected; 8–32%) and predation on free-living parasite life-cycle stages (4–30%). Parasite life-cycle stages had, on average, between 4.2 and 14.2 predators. Among the food webs, as predator richness increased, the number of links exploited by trophically transmitted parasites increased at about the same rate as did the number of links where these stages serve as prey. On the whole, our analyses suggest that predation on parasites has important consequences for both predators and parasites, and food web structure. Because our analysis is solely based on topological webs, determining the strength of these interactions is a promising avenue for future research.

  7. Infection by Haemoproteus parasites in four species of frigatebirds and the description of a new species of Haemoproteus (Haemosporida: Haemoproteidae)

    USGS Publications Warehouse

    Merino, Santiago; Hennicke, Janos; Martinez, Javier; Ludynia, Katrin; Torres, Roxana; Work, Thierry M.; Stroud, Stedson; Masello, Juan F.; Quillfeldt, Petra

    2012-01-01

    Among seabirds, the fregatids stand out with a high prevalence of blood parasites. Four of 5 species in this family have been found to be infected with Haemoproteus; however, complete species descriptions with molecular phylogeny are lacking. Seventy-five samples from 4 species of frigatebirds, i.e., Fregata andrewsi, Fregata minor, Fregata magnificens, and Fregata aquila, were screened for infections caused by species of Haemoproteus. Four different parasite haplotypes were found infecting frigatebirds based on the sequencing of a fragment of the cytochrome b gene. Two haplotypes belong to the subgenus Parahaemoproteus, and the other 2 correspond to haplotypes within the subgenus Haemoproteus. The more prevalent and cosmopolitan Parahaemoproteus haplotype (FregPHae1) was phylogenetically grouped with other Haemoproteus parasites infecting non-passerine birds, but it could not be detected from the single sample from F. aquila. The other Parahaemoproteus haplotype (FregPHae2) was not phylogenetically clustered with parasites infecting non-passerine birds, and it was sequenced from a single (1 each) F. andrewsi and F. minor. Blood smears from F. andrewsi infected only by FregPHae1 haplotype showed sufficient gametocytes to allow description of a new species, Haemoproteus valkiūnasi sp. nov. In contrast to Haemoproteus iwa, the only previously known blood parasite infecting frigatebirds and described from F. minor from Galapagos Islands, parasites from F. andrewsi (1) are shorter with no contact of gametocyte with host cell membrane, (2) have fewer pigment granules, and (3) have wider microgametocytes, with a smaller host nuclear displacement. In contrast, patent single infections corresponding to the cosmopolitan haplotype of the subgenus Haemoproteus (FregHae1) were also found in samples from 1 F. andrewsi, 1 F. minor, and 1 F. aquila. In all these cases, the number of microgametocytes was very low, resembling H. iwa, which lacks microgametocytes in the original

  8. 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.

  9. Ecosystem consequences of fish parasites

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2008-01-01

    In most aquatic ecosystems, fishes are hosts to parasites and, sometimes, these parasites can affect fish biology. Some of the most dramatic cases occur when fishes are intermediate hosts for larval parasites. For example, fishes in southern California estuaries are host to many parasites. The most common of these parasites, Euhaplorchis californiensis, infects the brain of the killifish Fundulus parvipinnis and alters its behaviour, making the fish 10–30 times more susceptible to predation by the birds that serve as its definitive host. Parasites like E. californiensis are embedded in food webs because they require trophic transmission. In the Carpinteria Salt Marsh estuarine food web, parasites dominate the links and comprise substantial amount of biomass. Adding parasites to food webs alters important network statistics such as connectance and nestedness. Furthermore, some free-living stages of parasites are food items for free-living species. For instance, fishes feed on trematode cercariae. Being embedded in food webs makes parasites sensitive to changes in the environment. In particular, fishing and environmental disturbance, by reducing fish populations, may reduce parasite populations. Indirect evidence suggests a decrease in parasites in commercially fished species over the past three decades. In addition, environmental degradation can affect fish parasites. For these reasons, parasites in fishes may serve as indicators of environmental impacts.

  10. Molecular phylogeny and morphological evolution of the Acantharia (Radiolaria).

    PubMed

    Decelle, Johan; Suzuki, Noritoshi; Mahé, Fredéric; de Vargas, Colomban; Not, Fabrice

    2012-05-01

    Acantharia are ubiquitous and abundant rhizarian protists in the world ocean. The skeleton made of strontium sulphate and the fact that certain harbour microalgal endosymbionts make them key planktonic players for the ecology of marine ecosystems. Based on morphological criteria, the current taxonomy of Acantharia was established by W.T. Schewiakoff in 1926, since when no major revision has been undertaken. Here, we established the first comprehensive molecular phylogeny from single morphologically-identified acantharian cells, isolated from various oceans. Our phylogenetic analyses based on 78 18S rDNA and 107 partial 28S rDNA revealed the existence of 6 main clades, sub-divided into 13 sub-clades. The polyphyletic nature of acantharian families and genera demonstrates the need for revision of the current taxonomy. This molecular phylogeny, which highlights the taxonomic relevance of specific morphological criteria, such as the presence of a shell and the organisation of the central junction, provides a robust phylogenetic framework for future taxonomic emendation. Finally, mapping all the existing environmental sequences available to date from different marine ecosystems onto our reference phylogeny unveiled another 3 clades and improved the understanding of the biogeography and ecology of Acantharia. Copyright © 2011 Elsevier GmbH. All rights reserved.

  11. Phylogeny of Anophelinae using mitochondrial protein coding genes

    PubMed Central

    de Oliveira, Tatiane Marques Porangaba; Bergo, Eduardo S.; Conn, Jan E.; Sant’Ana, Denise Cristina; Nagaki, Sandra Sayuri; Nihei, Silvio; Lamas, Carlos Einicker; González, Christian; Moreira, Caio Cesar; Sallum, Maria Anice Mureb

    2017-01-01

    Malaria is a vector-borne disease that is a great burden on the poorest and most marginalized communities of the tropical and subtropical world. Approximately 41 species of Anopheline mosquitoes can effectively spread species of Plasmodium parasites that cause human malaria. Proposing a natural classification for the subfamily Anophelinae has been a continuous effort, addressed using both morphology and DNA sequence data. The monophyly of the genus Anopheles, and phylogenetic placement of the genus Bironella, subgenera Kerteszia, Lophopodomyia and Stethomyia within the subfamily Anophelinae, remain in question. To understand the classification of Anophelinae, we inferred the phylogeny of all three genera (Anopheles, Bironella, Chagasia) and major subgenera by analysing the amino acid sequences of the 13 protein coding genes of 150 newly sequenced mitochondrial genomes of Anophelinae and 18 newly sequenced Culex species as outgroup taxa, supplemented with 23 mitogenomes from GenBank. Our analyses generally place genus Bironella within the genus Anopheles, which implies that the latter as it is currently defined is not monophyletic. With some inconsistencies, Bironella was placed within the major clade that includes Anopheles, Cellia, Kerteszia, Lophopodomyia, Nyssorhynchus and Stethomyia, which were found to be monophyletic groups within Anophelinae. Our findings provided robust evidence for elevating the monophyletic groupings Kerteszia, Lophopodomyia, Nyssorhynchus and Stethomyia to genus level; genus Anopheles to include subgenera Anopheles, Baimaia, Cellia and Christya; Anopheles parvus to be placed into a new genus; Nyssorhynchus to be elevated to genus level; the genus Nyssorhynchus to include subgenera Myzorhynchella and Nyssorhynchus; Anopheles atacamensis and Anopheles pictipennis to be transferred from subgenus Nyssorhynchus to subgenus Myzorhynchella; and subgenus Nyssorhynchus to encompass the remaining species of Argyritarsis and Albimanus Sections

  12. Blastocystis phylogeny among various isolates from humans to insects.

    PubMed

    Yoshikawa, Hisao; Koyama, Yukiko; Tsuchiya, Erika; Takami, Kazutoshi

    2016-12-01

    Blastocystis is a common unicellular eukaryotic parasite found not only in humans, but also in various kinds of animal species worldwide. Since Blastocystis isolates are morphologically indistinguishable, many molecular biological approaches have been applied to classify these isolates. The complete or partial sequences of the small subunit rRNA gene (SSU rDNA) are mainly used for comparisons and phylogenetic analyses among Blastocystis isolates. However, various lengths of the partial SSU rDNA sequence have been used for phylogenetic inference among genetically different isolates. Based on the complete SSU rDNA sequences, consensus terminology of nine subtypes (STs) of Blastocystis sp. that were supported by phylogenetically monophyletic nine clades was proposed in 2007. Thereafter, eight additional kinds of STs comprising non-human mammalian Blastocystis isolates have been reported based on the phylogeny of SSU rDNA sequences, while STs 11 and 12 were only proposed on the base of partial sequences. Although many sequence data from mammalian and avian Blastocystis are registered in GenBank, only limited data on SSU rDNA are available for poikilotherm-derived Blastocystis isolates. Therefore, the phylogenetic positions of the reptilian/amphibian Blastocystis clades are unstable. The phylogenetic inference of various STs comprising mammalian and/or avian Blastocystis isolates was verified herein based on comparisons between partial and complete SSU rDNA sequences, and the phylogenetic positions of reptilian and amphibian Blastocystis isolates were also investigated using 14 new Blastocystis isolates from reptiles with all known isolates from other reptilians, amphibians, and insects registered in GenBank. Copyright © 2016. Published by Elsevier Ireland Ltd.

  13. 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.

  14. Asian horses deepen the MSY phylogeny.

    PubMed

    Felkel, S; Vogl, C; Rigler, D; Jagannathan, V; Leeb, T; Fries, R; Neuditschko, M; Rieder, S; Velie, B; Lindgren, G; Rubin, C-J; Schlötterer, C; Rattei, T; Brem, G; Wallner, B

    2018-02-01

    Humans have shaped the population history of the horse ever since domestication about 5500 years ago. Comparative analyses of the Y chromosome can illuminate the paternal origin of modern horse breeds. This may also reveal different breeding strategies that led to the formation of extant breeds. Recently, a horse Y-chromosomal phylogeny of modern horses based on 1.46 Mb of the male-specific Y (MSY) was generated. We extended this dataset with 52 samples from five European, two American and seven Asian breeds. As in the previous study, almost all modern European horses fall into a crown group, connected via a few autochthonous Northern European lineages to the outgroup, the Przewalski's Horse. In total, we now distinguish 42 MSY haplotypes determined by 158 variants within domestic horses. Asian horses show much higher diversity than previously found in European breeds. The Asian breeds also introduce a deep split to the phylogeny, preliminarily dated to 5527 ± 872 years. We conclude that the deep splitting Asian Y haplotypes are remnants of a far more diverse ancient horse population, whose haplotypes were lost in other lineages. © 2018 Stichting International Foundation for Animal Genetics.

  15. Phylogeny of mycoplasmalike organisms (phytoplasmas): a basis for their classification.

    PubMed Central

    Gundersen, D E; Lee, I M; Rehner, S A; Davis, R E; Kingsbury, D T

    1994-01-01

    A global phylogenetic analysis using parsimony of 16S rRNA gene sequences from 46 mollicutes, 19 mycoplasmalike organisms (MLOs) (new trivial name, phytoplasmas), and several related bacteria placed the MLOs definitively among the members of the class Mollicutes and revealed that MLOs form a large discrete monophyletic clade, paraphyletic to the Acholeplasma species, within the Anaeroplasma clade. Within the MLO clade resolved in the global mollicutes phylogeny and a comprehensive MLO phylogeny derived by parsimony analyses of 16S rRNA gene sequences from 30 diverse MLOs representative of nearly all known distinct MLO groups, five major phylogenetic groups with a total of 11 distinct subclades (monophyletic groups or taxa) could be recognized. These MLO subclades (roman numerals) and designated type strains were as follows: i, Maryland aster yellows AY1; ii, apple proliferation AP-A; iii, peanut witches'-broom PnWB; iv, Canada peach X CX; v, rice yellow dwarf RYD; vi, pigeon pea witches'-broom PPWB; vii, palm lethal yellowing LY; viii, ash yellows AshY; ix, clover proliferation CP; x, elm yellows EY; and xi, loofah witches'-broom LfWB. The designations of subclades and their phylogenetic positions within the MLO clade were supported by a congruent phylogeny derived by parsimony analyses of ribosomal protein L22 gene sequences from most representative MLOs. On the basis of the phylogenies inferred in the present study, we propose that MLOs should be represented taxonomically at the minimal level of genus and that each phylogenetically distinct MLO subclade identified should represent at least a distinct species under this new genus. Images PMID:8071198

  16. Role of parasitic vaccines in integrated control of parasitic diseases in livestock

    PubMed Central

    Sharma, Neelu; Singh, Veer; Shyma, K. P.

    2015-01-01

    Parasitic infections adversely affect animal’s health and threaten profitable animal production, thus affecting the economy of our country. These infections also play a major role in the spread of zoonotic diseases. Parasitic infections cause severe morbidity and mortality in animals especially those affecting the gastrointestinal system and thus affect the economy of livestock owner by decreasing the ability of the farmer to produce economically useful animal products. Due to all these reasons proper control of parasitic infection is critically important for sustained animal production. The most common and regularly used method to control parasitic infection is chemotherapy, which is very effective but has several disadvantages like drug resistance and drug residues. Integrated approaches to control parasitic infections should be formulated including grazing management, biological control, genetic resistance of hosts, and parasitic vaccines. India ranks first in cattle and buffalo population, but the majority of livestock owners have fewer herds, so other measures like grazing management, biological control, genetic resistance of hosts are not much practical to use. The most sustainable and economical approach to control parasitic infection in our country is to vaccinate animals, although vaccines increase the initial cost, but the immunity offered by the vaccine are long lived. Thus, vaccination of animals for various clinical, chronic, subclinical parasitic infections will be a cheaper and effective alternative to control parasitic infection for long time and improve animal production. PMID:27047140

  17. Parasites in marine food webs

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2013-01-01

    Most species interactions probably involve parasites. This review considers the extent to which marine ecologists should consider parasites to fully understand marine communities. Parasites are influential parts of food webs in estuaries, temperate reefs, and coral reefs, but their ecological importance is seldom recognized. Though difficult to observe, parasites can have substantial biomass, and they can be just as common as free-living consumers after controlling for body mass and trophic level. Parasites have direct impacts on the energetics of their hosts and some affect host behaviors, with ecosystem-level consequences. Although they cause disease, parasites are sensitive components of ecosystems. In particular, they suffer secondary extinctions due to biodiversity loss. Some parasites can also return to a system after habitat restoration. For these reasons, parasites can make good indicators of ecosystem integrity. Fishing can indirectly increase or decrease parasite populations and the effects of climate change on parasites are likely to be equally as complex.

  18. Shark tales: a molecular species-level phylogeny of sharks (Selachimorpha, Chondrichthyes).

    PubMed

    Vélez-Zuazo, Ximena; Agnarsson, Ingi

    2011-02-01

    Sharks are a diverse and ecologically important group, including some of the ocean's largest predatory animals. Sharks are also commercially important, with many species suffering overexploitation and facing extinction. However, despite a long evolutionary history, commercial, and conservation importance, phylogenetic relationships within the sharks are poorly understood. To date, most studies have either focused on smaller clades within sharks, or sampled taxa sparsely across the group. A more detailed species-level phylogeny will offer further insights into shark taxonomy, provide a tool for comparative analyses, as well as facilitating phylogenetic estimates of conservation priorities. We used four mitochondrial and one nuclear gene to investigate the phylogenetic relationships of 229 species (all eight Orders and 31 families) of sharks, more than quadrupling the number of taxon sampled in any prior study. The resulting Bayesian phylogenetic hypothesis agrees with prior studies on the major relationships of the sharks phylogeny; however, on those relationships that have proven more controversial, it differs in several aspects from the most recent molecular studies. The phylogeny supports the division of sharks into two major groups, the Galeomorphii and Squalimorphii, rejecting the hypnosqualean hypothesis that places batoids within sharks. Within the squalimorphs the orders Hexanchiformes, Squatiniformes, Squaliformes, and Pristiophoriformes are broadly monophyletic, with minor exceptions apparently due to missing data. Similarly, within Galeomorphs, the orders Heterodontiformes, Lamniformes, Carcharhiniformes, and Orectolobiformes are broadly monophyletic, with a couple of species 'misplaced'. In contrast, many of the currently recognized shark families are not monophyletic according to our results. Our phylogeny offers some of the first clarification of the relationships among families of the order Squaliformes, a group that has thus far received relatively

  19. Character analysis and the integration of molecular and morphological data in an understanding of sand dollar phylogeny.

    PubMed

    Marshall, C R

    1992-03-01

    Reconciling discordant morphological and molecular phylogenies remains a problem in modern systematics. By examining conflicting DNA-hybridization and morphological phylogenies of sand dollars, I show that morphological criteria may be used to help evaluate the reliability of molecular phylogenies where they differ from morphological trees. All available criteria for assessing the reliability of DNA-hybridization phylogenies suggest that the sand dollar DNA-hybridization phylogeny is robust. Standard homology-recognition criteria are used to assess the a priori reliabilities of the morphological attributes associated with the node drawn into question by the DNA data, and it is shown that these attributes are among the least phylogenetically informative of all the morphological characters. Moreover, the questioned node has the smallest number of supporting characters, and most of these characters are associated with the food grooves, which suggests that they may be functionally correlated. Thus, on the basis of the analysis of the morphological data and given the robustness of the DNA tree, the DNA phylogeny is preferred. Further, paleobiogeographic data support the DNA tree rather than the morphological tree, and a plausible heterochronic mechanism has been proposed that may account for the homoplasious morphological evolution that must have occurred if the DNA tree is correct.

  20. Reduction of parasitic lasing

    NASA Technical Reports Server (NTRS)

    Storm, Mark E. (Inventor)

    1994-01-01

    A technique was developed which carefully retro-reflects precisely controlled amounts of light back into a laser system thereby intentionally forcing the laser system components to oscillate in a new resonator called the parasitic oscillator. The parasitic oscillator uses the laser system to provide the gain and an external mirror is used to provide the output coupling of the new resonator. Any change of gain or loss inside the new resonator will directly change the lasing threshold of the parasitic oscillator. This change in threshold can be experimentally measured as a change in the absolute value of reflectivity, provided by the external mirror, necessary to achieve lasing in the parasitic oscillator. Discrepancies between experimental data and a parasitic oscillator model are direct evidence of optical misalignment or component performance problems. Any changes in the optical system can instantly be measured as a change in threshold for the parasitic oscillator. This technique also enables aligning the system for maximum parasitic suppression with the system fully operational.

  1. How have fisheries affected parasite communities?

    USGS Publications Warehouse

    Wood, Chelsea L.; Lafferty, Kevin D.

    2015-01-01

    To understand how fisheries affect parasites, we conducted a meta-analysis of studies that contrasted parasite assemblages in fished and unfished areas. Parasite diversity was lower in hosts from fished areas. Larger hosts had a greater abundance of parasites, suggesting that fishing might reduce the abundance of parasites by selectively removing the largest, most heavily parasitized individuals. After controlling for size, the effect of fishing on parasite abundance varied according to whether the host was fished and the parasite's life cycle. Parasites of unfished hosts were more likely to increase in abundance in response to fishing than were parasites of fished hosts, possibly due to compensatory increases in the abundance of unfished hosts. While complex life cycle parasites tended to decline in abundance in response to fishing, directly transmitted parasites tended to increase. Among complex life cycle parasites, those with fished hosts tended to decline in abundance in response to fishing, while those with unfished hosts tended to increase. However, among directly transmitted parasites, responses did not differ between parasites with and without fished hosts. This work suggests that parasite assemblages are likely to change substantially in composition in increasingly fished ecosystems, and that parasite life history and fishing status of the host are important in predicting the response of individual parasite species or groups to fishing.

  2. 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.

  3. Viruses of parasites as actors in the parasite-host relationship: A "ménage à trois".

    PubMed

    Gómez-Arreaza, Amaranta; Haenni, Anne-Lise; Dunia, Irene; Avilán, Luisana

    2017-02-01

    The complex parasite-host relationship involves multiple mechanisms. Moreover, parasites infected by viruses modify this relationship adding more complexity to the system that now comprises three partners. Viruses infecting parasites were described several decades ago. However, until recently little was known about the viruses involved and their impact on the resulting disease caused to the hosts. To clarify this situation, we have concentrated on parasitic diseases caused to humans and on how virus-infected parasites could alter the symptoms inflicted on the human host. It is clear that the effect caused to the human host depends on the virus and on the parasite it has infected. Consequently, the review is divided as follows: Viruses with a possible effect on the virulence of the parasite. This section reviews pertinent articles showing that infection of parasites by viruses might increase the detrimental effect of the tandem virus-parasite on the human host (hypervirulence) or decrease virulence of the parasite (hypovirulence). Parasites as vectors affecting the transmission of viruses. In some cases, the virus-infected parasite might facilitate the transfer of the virus to the human host. Parasites harboring viruses with unidentified effects on their host. In spite of recently renewed interest in parasites in connection with their viruses, there still remains a number of cases in which the effect of the virus of a given parasite on the human host remains ambiguous. The triangular relationship between the virus, the parasite and the host, and the modulation of the pathogenicity and virulence of the parasites by viruses should be taken into account in the rationale of fighting against parasites. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Predation on transmission stages reduces parasitism: sea anemones consume transmission stages of a barnacle parasite.

    PubMed

    Fong, Caitlin R; Kuris, Armand M

    2017-06-01

    While parasites serve as prey, it is unclear how the spatial distribution of parasite predators provides transmission control and influences patterns of parasitism. Because many of its organisms are sessile, the rocky intertidal zone is a valuable but little used system to understand spatial patterns of parasitism and elucidate the underlying mechanisms driving these patterns. Sea anemones and barnacles are important space competitors in the rocky intertidal zone along the Pacific coast of North America. Anemones are voracious, indiscriminate predators; thus, they may intercept infectious stages of parasites before they reach a host. We investigate whether a sea anemone protects an associated barnacle from parasitism by Hemioniscus balani, an isopod parasitic castrator. At Coal Oil Point, Santa Barbara, California USA, 29% of barnacles were within 1 cm from an anemone at the surveyed tidal height. Barnacles associated with anemones had reduced parasite prevalence and higher reproductive productivity than those remote from sea anemones. In the laboratory, anemones readily consumed the transmission stage of the parasite. Hence, anemone consumption of parasite transmission stages may provide a mechanism by which community context regulates parasite prevalence at a local scale. Our results suggest predation may be an important process providing parasite transmission control.

  5. Parasite Carbohydrate Vaccines.

    PubMed

    Jaurigue, Jonnel A; Seeberger, Peter H

    2017-01-01

    Vaccination is an efficient means of combating infectious disease burden globally. However, routine vaccines for the world's major human parasitic diseases do not yet exist. Vaccines based on carbohydrate antigens are a viable option for parasite vaccine development, given the proven success of carbohydrate vaccines to combat bacterial infections. We will review the key components of carbohydrate vaccines that have remained largely consistent since their inception, and the success of bacterial carbohydrate vaccines. We will then explore the latest developments for both traditional and non-traditional carbohydrate vaccine approaches for three of the world's major protozoan parasitic diseases-malaria, toxoplasmosis, and leishmaniasis. The traditional prophylactic carbohydrate vaccine strategy is being explored for malaria. However, given that parasite disease biology is complex and often arises from host immune responses to parasite antigens, carbohydrate vaccines against deleterious immune responses in host-parasite interactions are also being explored. In particular, the highly abundant glycosylphosphatidylinositol molecules specific for Plasmodium, Toxoplasma , and Leishmania spp. are considered exploitable antigens for this non-traditional vaccine approach. Discussion will revolve around the application of these protozoan carbohydrate antigens for vaccines currently in preclinical development.

  6. Parasite Carbohydrate Vaccines

    PubMed Central

    Jaurigue, Jonnel A.; Seeberger, Peter H.

    2017-01-01

    Vaccination is an efficient means of combating infectious disease burden globally. However, routine vaccines for the world's major human parasitic diseases do not yet exist. Vaccines based on carbohydrate antigens are a viable option for parasite vaccine development, given the proven success of carbohydrate vaccines to combat bacterial infections. We will review the key components of carbohydrate vaccines that have remained largely consistent since their inception, and the success of bacterial carbohydrate vaccines. We will then explore the latest developments for both traditional and non-traditional carbohydrate vaccine approaches for three of the world's major protozoan parasitic diseases—malaria, toxoplasmosis, and leishmaniasis. The traditional prophylactic carbohydrate vaccine strategy is being explored for malaria. However, given that parasite disease biology is complex and often arises from host immune responses to parasite antigens, carbohydrate vaccines against deleterious immune responses in host-parasite interactions are also being explored. In particular, the highly abundant glycosylphosphatidylinositol molecules specific for Plasmodium, Toxoplasma, and Leishmania spp. are considered exploitable antigens for this non-traditional vaccine approach. Discussion will revolve around the application of these protozoan carbohydrate antigens for vaccines currently in preclinical development. PMID:28660174

  7. Phylogenies support out-of-equilibrium models of biodiversity.

    PubMed

    Manceau, Marc; Lambert, Amaury; Morlon, Hélène

    2015-04-01

    There is a long tradition in ecology of studying models of biodiversity at equilibrium. These models, including the influential Neutral Theory of Biodiversity, have been successful at predicting major macroecological patterns, such as species abundance distributions. But they have failed to predict macroevolutionary patterns, such as those captured in phylogenetic trees. Here, we develop a model of biodiversity in which all individuals have identical demographic rates, metacommunity size is allowed to vary stochastically according to population dynamics, and speciation arises naturally from the accumulation of point mutations. We show that this model generates phylogenies matching those observed in nature if the metacommunity is out of equilibrium. We develop a likelihood inference framework that allows fitting our model to empirical phylogenies, and apply this framework to various mammalian families. Our results corroborate the hypothesis that biodiversity dynamics are out of equilibrium. © 2015 John Wiley & Sons Ltd/CNRS.

  8. Diphyllobothriasis in a U.S. Military Aviator.

    PubMed

    Kasteler, Stephen D

    2018-05-01

    Diphyllobothriasis is estimated to afflict 10-20 million people worldwide; however, this is the first case reported in a United States military aviator. Among the largest parasites of humans, the "fish tapeworm" grows from 2-15 m in length, can live >20 yr in the intestines, and is contracted through consumption of uncooked, unfrozen freshwater or anadromous fish species. A 32-yr-old male F-22 pilot presented with mild stomach cramping, bloating, nausea, and intermittent loose stools. Symptoms were relieved with bismuth subsalicylate until several days later when the patient, during otherwise normal bowel movements, extracted multiple broken segments of tapeworm. Although physically asymptomatic, he was psychologically disturbed. Based on the large number of ova with characteristic shape, size, color, and operculum, coupled with the flattened body, yellowish coloration, and rectangular proglottids with centrally located "rosette" uteri, he was diagnosed with diphyllobothriasis (likely D. latum or D. nihonkaiense). Successful treatment with a single oral dose of praziquantel (>10 mg · kg-1) was confirmed by negative stool examination over 60 d posttreatment. He likely contracted the parasite from ingesting salmon sushi or sashimi while previously stationed in Japan. Despite only mild physical symptoms, the pilot's psychological distress and distraction from knowing about the meters-long tapeworm was significant. Prompt treatment was paramount to resumption of military operations. Aviators should be educated and encouraged to eat only well-cooked or previously frozen fish, especially when indulging in cultural cuisine.Kasteler SD. Diphyllobothriasis in a U.S. military aviator. Aerosp Med Hum Perform. 2018; 89(5):473-477.

  9. Whole-Genome Sequencing of Theileria parva Strains Provides Insight into Parasite Migration and Diversification in the African Continent

    PubMed Central

    Hayashida, Kyoko; Abe, Takashi; Weir, William; Nakao, Ryo; Ito, Kimihito; Kajino, Kiichi; Suzuki, Yutaka; Jongejan, Frans; Geysen, Dirk; Sugimoto, Chihiro

    2013-01-01

    The disease caused by the apicomplexan protozoan parasite Theileria parva, known as East Coast fever or Corridor disease, is one of the most serious cattle diseases in Eastern, Central, and Southern Africa. We performed whole-genome sequencing of nine T. parva strains, including one of the vaccine strains (Kiambu 5), field isolates from Zambia, Uganda, Tanzania, or Rwanda, and two buffalo-derived strains. Comparison with the reference Muguga genome sequence revealed 34 814–121 545 single nucleotide polymorphisms (SNPs) that were more abundant in buffalo-derived strains. High-resolution phylogenetic trees were constructed with selected informative SNPs that allowed the investigation of possible complex recombination events among ancestors of the extant strains. We further analysed the dN/dS ratio (non-synonymous substitutions per non-synonymous site divided by synonymous substitutions per synonymous site) for 4011 coding genes to estimate potential selective pressure. Genes under possible positive selection were identified that may, in turn, assist in the identification of immunogenic proteins or vaccine candidates. This study elucidated the phylogeny of T. parva strains based on genome-wide SNPs analysis with prediction of possible past recombination events, providing insight into the migration, diversification, and evolution of this parasite species in the African continent. PMID:23404454

  10. Whole-genome sequencing of Theileria parva strains provides insight into parasite migration and diversification in the African continent.

    PubMed

    Hayashida, Kyoko; Abe, Takashi; Weir, William; Nakao, Ryo; Ito, Kimihito; Kajino, Kiichi; Suzuki, Yutaka; Jongejan, Frans; Geysen, Dirk; Sugimoto, Chihiro

    2013-06-01

    The disease caused by the apicomplexan protozoan parasite Theileria parva, known as East Coast fever or Corridor disease, is one of the most serious cattle diseases in Eastern, Central, and Southern Africa. We performed whole-genome sequencing of nine T. parva strains, including one of the vaccine strains (Kiambu 5), field isolates from Zambia, Uganda, Tanzania, or Rwanda, and two buffalo-derived strains. Comparison with the reference Muguga genome sequence revealed 34 814-121 545 single nucleotide polymorphisms (SNPs) that were more abundant in buffalo-derived strains. High-resolution phylogenetic trees were constructed with selected informative SNPs that allowed the investigation of possible complex recombination events among ancestors of the extant strains. We further analysed the dN/dS ratio (non-synonymous substitutions per non-synonymous site divided by synonymous substitutions per synonymous site) for 4011 coding genes to estimate potential selective pressure. Genes under possible positive selection were identified that may, in turn, assist in the identification of immunogenic proteins or vaccine candidates. This study elucidated the phylogeny of T. parva strains based on genome-wide SNPs analysis with prediction of possible past recombination events, providing insight into the migration, diversification, and evolution of this parasite species in the African continent.

  11. Niche metabolism in parasitic protozoa

    PubMed Central

    Ginger, Michael L

    2005-01-01

    Complete or partial genome sequences have recently become available for several medically and evolutionarily important parasitic protozoa. Through the application of bioinformatics complete metabolic repertoires for these parasites can be predicted. For experimentally intractable parasites insight provided by metabolic maps generated in silico has been startling. At its more extreme end, such bioinformatics reckoning facilitated the discovery in some parasites of mitochondria remodelled beyond previous recognition, and the identification of a non-photosynthetic chloroplast relic in malarial parasites. However, for experimentally tractable parasites, mapping of the general metabolic terrain is only a first step in understanding how the parasite modulates its streamlined, yet still often puzzlingly complex, metabolism in order to complete life cycles within host, vector, or environment. This review provides a comparative overview and discussion of metabolic strategies used by several different parasitic protozoa in order to subvert and survive host defences, and illustrates how genomic data contribute to the elucidation of parasite metabolism. PMID:16553311

  12. A novel molecular marker for the study of Neotropical cichlid phylogeny.

    PubMed

    Fabrin, T M C; Gasques, L S; Prioli, S M A P; Prioli, A J

    2015-12-22

    The use of molecular markers has contributed to phylogeny and to the reconstruction of species' evolutionary history. Each region of the genome has different evolution rates, which may or may not identify phylogenetic signal at different levels. Therefore, it is important to assess new molecular markers that can be used for phylogenetic reconstruction. Regions that may be associated with species characteristics and are subject to selective pressure, such as opsin genes, which encode proteins related to the visual system and are widely expressed by Cichlidae family members, are interesting. Our aim was to identify a new nuclear molecular marker that could establish the phylogeny of Neotropical cichlids and is potentially correlated with the visual system. We used Bayesian inference and maximum likelihood analysis to support the use of the nuclear opsin LWS gene in the phylogeny of eight Neotropical cichlid species. Their use concatenated to the mitochondrial gene COI was also tested. The LWS gene fragment comprised the exon 2-4 region, including the introns. The LWS gene provided good support for both analyses up to the genus level, distinguishing the studied species, and when concatenated to the COI gene, there was a good support up to the species level. Another benefit of utilizing this region, is that some polymorphisms are associated with changes in spectral properties of the LWS opsin protein, which constitutes the visual pigment that absorbs red light. Thus, utilization of this gene as a molecular marker to study the phylogeny of Neotropical cichlids is promising.

  13. Retaliatory mafia behavior by a parasitic cowbird favors host acceptance of parasitic eggs.

    PubMed

    Hoover, Jeffrey P; Robinson, Scott K

    2007-03-13

    Why do many hosts accept costly avian brood parasitism even when parasitic eggs and nestlings differ dramatically in appearance from their own? Scientists argue that evolutionary lag or equilibrium can explain this evolutionary enigma. Few, however, consider the potential of parasitic birds to enforce acceptance by destroying eggs or nestlings of hosts that eject parasitic eggs and thereby reject parasitism. This retaliatory "mafia" behavior has been reported in one species of parasitic cuckoo but never in parasitic cowbirds. Here we present experimental evidence of mafia behavior in the brown-headed cowbird (Molothrus ater), a widely distributed North American brood parasite. We manipulated ejection of cowbird eggs and cowbird access to predator-proof nests in a common host to test experimentally for mafia behavior. When cowbird access was allowed, 56% of "ejector" nests were depredated compared with only 6% of "accepter" nests. No nests were destroyed when cowbird access was always denied or when access was denied after we removed cowbird eggs, indicating that cowbirds were responsible. Nonparasitized nests were depredated at an intermediate rate (20%) when cowbirds were allowed access, suggesting that cowbirds may occasionally "farm" hosts to create additional opportunities for parasitism. Cowbirds parasitized most (85%) renests of the hosts whose nests were depredated. Ejector nests produced 60% fewer host offspring than accepter nests because of the predatory behavior attributed to cowbirds. Widespread predatory behaviors in cowbirds could slow the evolution of rejection behaviors and further threaten populations of some of the >100 species of regular cowbird hosts.

  14. Retaliatory mafia behavior by a parasitic cowbird favors host acceptance of parasitic eggs

    PubMed Central

    Hoover, Jeffrey P.; Robinson, Scott K.

    2007-01-01

    Why do many hosts accept costly avian brood parasitism even when parasitic eggs and nestlings differ dramatically in appearance from their own? Scientists argue that evolutionary lag or equilibrium can explain this evolutionary enigma. Few, however, consider the potential of parasitic birds to enforce acceptance by destroying eggs or nestlings of hosts that eject parasitic eggs and thereby reject parasitism. This retaliatory “mafia” behavior has been reported in one species of parasitic cuckoo but never in parasitic cowbirds. Here we present experimental evidence of mafia behavior in the brown-headed cowbird (Molothrus ater), a widely distributed North American brood parasite. We manipulated ejection of cowbird eggs and cowbird access to predator-proof nests in a common host to test experimentally for mafia behavior. When cowbird access was allowed, 56% of “ejector” nests were depredated compared with only 6% of “accepter” nests. No nests were destroyed when cowbird access was always denied or when access was denied after we removed cowbird eggs, indicating that cowbirds were responsible. Nonparasitized nests were depredated at an intermediate rate (20%) when cowbirds were allowed access, suggesting that cowbirds may occasionally “farm” hosts to create additional opportunities for parasitism. Cowbirds parasitized most (85%) renests of the hosts whose nests were depredated. Ejector nests produced 60% fewer host offspring than accepter nests because of the predatory behavior attributed to cowbirds. Widespread predatory behaviors in cowbirds could slow the evolution of rejection behaviors and further threaten populations of some of the >100 species of regular cowbird hosts. PMID:17360549

  15. Parasite Microbiome Project: Systematic Investigation of Microbiome Dynamics within and across Parasite-Host Interactions.

    PubMed

    Dheilly, Nolwenn M; Bolnick, Daniel; Bordenstein, Seth; Brindley, Paul J; Figuères, Cédric; Holmes, Edward C; Martínez Martínez, Joaquín; Phillips, Anna J; Poulin, Robert; Rosario, Karyna

    2017-01-01

    Understanding how microbiomes affect host resistance, parasite virulence, and parasite-associated diseases requires a collaborative effort between parasitologists, microbial ecologists, virologists, and immunologists. We hereby propose the Parasite Microbiome Project to bring together researchers with complementary expertise and to study the role of microbes in host-parasite interactions. Data from the Parasite Microbiome Project will help identify the mechanisms driving microbiome variation in parasites and infected hosts and how that variation is associated with the ecology and evolution of parasites and their disease outcomes. This is a call to arms to prevent fragmented research endeavors, encourage best practices in experimental approaches, and allow reliable comparative analyses across model systems. It is also an invitation to foundations and national funding agencies to propel the field of parasitology into the microbiome/metagenomic era.

  16. A molecular phylogeny of anseriformes based on mitochondrial DNA analysis.

    PubMed

    Donne-Goussé, Carole; Laudet, Vincent; Hänni, Catherine

    2002-06-01

    To study the phylogenetic relationships among Anseriformes, sequences for the complete mitochondrial control region (CR) were determined from 45 waterfowl representing 24 genera, i.e., half of the existing genera. To confirm the results based on CR analysis we also analyzed representative species based on two mitochondrial protein-coding genes, cytochrome b (cytb) and NADH dehydrogenase subunit 2 (ND2). These data allowed us to construct a robust phylogeny of the Anseriformes and to compare it with existing phylogenies based on morphological or molecular data. Chauna and Dendrocygna were identified as early offshoots of the Anseriformes. All the remaining taxa fell into two clades that correspond to the two subfamilies Anatinae and Anserinae. Within Anserinae Branta and Anser cluster together, whereas Coscoroba, Cygnus, and Cereopsis form a relatively weak clade with Cygnus diverging first. Five clades are clearly recognizable among Anatinae: (i) the Anatini with Anas and Lophonetta; (ii) the Aythyini with Aythya and Netta; (iii) the Cairinini with Cairina and Aix; (iv) the Mergini with Mergus, Bucephala, Melanitta, Callonetta, Somateria, and Clangula, and (v) the Tadornini with Tadorna, Chloephaga, and Alopochen. The Tadornini diverged early on from the Anatinae; then the Mergini and a large group that comprises the Anatini, Aythyini, Cairinini, and two isolated genera, Chenonetta and Marmaronetta, diverged. The phylogeny obtained with the control region appears more robust than the one obtained with mitochondrial protein-coding genes such as ND2 and cytb. This suggests that the CR is a powerful tool for bird phylogeny, not only at a small scale (i.e., relationships between species) but also at the family level. Whereas morphological analysis effectively resolved the split between Anatinae and Anserinae and the existence of some of the clades, the precise composition of the clades are different when morphological and molecular data are compared. (c) 2002 Elsevier

  17. Inevitability of Genetic Parasites

    PubMed Central

    Iranzo, Jaime; Puigbò, Pere; Lobkovsky, Alexander E.; Wolf, Yuri I.

    2016-01-01

    Abstract Almost all cellular life forms are hosts to diverse genetic parasites with various levels of autonomy including plasmids, transposons and viruses. Theoretical modeling of the evolution of primordial replicators indicates that parasites (cheaters) necessarily evolve in such systems and can be kept at bay primarily via compartmentalization. Given the (near) ubiquity, abundance and diversity of genetic parasites, the question becomes pertinent: are such parasites intrinsic to life? At least in prokaryotes, the persistence of parasites is linked to the rate of horizontal gene transfer (HGT). We mathematically derive the threshold value of the minimal transfer rate required for selfish element persistence, depending on the element duplication and loss rates as well as the cost to the host. Estimation of the characteristic gene duplication, loss and transfer rates for transposons, plasmids and virus-related elements in multiple groups of diverse bacteria and archaea indicates that most of these rates are compatible with the long term persistence of parasites. Notably, a small but non-zero rate of HGT is also required for the persistence of non-parasitic genes. We hypothesize that cells cannot tune their horizontal transfer rates to be below the threshold required for parasite persistence without experiencing highly detrimental side-effects. As a lower boundary to the minimum DNA transfer rate that a cell can withstand, we consider the process of genome degradation and mutational meltdown of populations through Muller’s ratchet. A numerical assessment of this hypothesis suggests that microbial populations cannot purge parasites while escaping Muller’s ratchet. Thus, genetic parasites appear to be virtually inevitable in cellular organisms. PMID:27503291

  18. Molecular Infectious Disease Epidemiology: Survival Analysis and Algorithms Linking Phylogenies to Transmission Trees

    PubMed Central

    Kenah, Eben; Britton, Tom; Halloran, M. Elizabeth; Longini, Ira M.

    2016-01-01

    Recent work has attempted to use whole-genome sequence data from pathogens to reconstruct the transmission trees linking infectors and infectees in outbreaks. However, transmission trees from one outbreak do not generalize to future outbreaks. Reconstruction of transmission trees is most useful to public health if it leads to generalizable scientific insights about disease transmission. In a survival analysis framework, estimation of transmission parameters is based on sums or averages over the possible transmission trees. A phylogeny can increase the precision of these estimates by providing partial information about who infected whom. The leaves of the phylogeny represent sampled pathogens, which have known hosts. The interior nodes represent common ancestors of sampled pathogens, which have unknown hosts. Starting from assumptions about disease biology and epidemiologic study design, we prove that there is a one-to-one correspondence between the possible assignments of interior node hosts and the transmission trees simultaneously consistent with the phylogeny and the epidemiologic data on person, place, and time. We develop algorithms to enumerate these transmission trees and show these can be used to calculate likelihoods that incorporate both epidemiologic data and a phylogeny. A simulation study confirms that this leads to more efficient estimates of hazard ratios for infectiousness and baseline hazards of infectious contact, and we use these methods to analyze data from a foot-and-mouth disease virus outbreak in the United Kingdom in 2001. These results demonstrate the importance of data on individuals who escape infection, which is often overlooked. The combination of survival analysis and algorithms linking phylogenies to transmission trees is a rigorous but flexible statistical foundation for molecular infectious disease epidemiology. PMID:27070316

  19. Parasites and marine invasions

    USGS Publications Warehouse

    Torchin, M.E.; Lafferty, K.D.; Kuris, A.M.

    2002-01-01

    Introduced marine species are a major environmental and economic problem. The rate of these biological invasions has substantially increased in recent years due to the globalization of the world's economies. The damage caused by invasive species is often a result of the higher densities and larger sizes they attain compared to where they are native. A prominent hypothesis explaining the success of introduced species is that they are relatively free of the effects of natural enemies. Most notably, they may encounter fewer parasites in their introduced range compared to their native range. Parasites are ubiquitous and pervasive in marine systems, yet their role in marine invasions is relatively unexplored. Although data on parasites of marine organisms exist, the extent to which parasites can mediate marine invasions, or the extent to which invasive parasites and pathogens are responsible for infecting or potentially decimating native marine species have not been examined. In this review, we present a theoretical framework to model invasion success and examine the evidence for a relationship between parasite presence and the success of introduced marine species. For this, we compare the prevalence and species richness of parasites in several introduced populations of marine species with populations where they are native. We also discuss the potential impacts of introduced marine parasites on native ecosystems.

  20. Functional genomics of a generalist parasitic plant: Laser microdissection of host-parasite interface reveals host-specific patterns of parasite gene expression

    PubMed Central

    2013-01-01

    Background Orobanchaceae is the only plant family with members representing the full range of parasitic lifestyles plus a free-living lineage sister to all parasitic lineages, Lindenbergia. A generalist member of this family, and an important parasitic plant model, Triphysaria versicolor regularly feeds upon a wide range of host plants. Here, we compare de novo assembled transcriptomes generated from laser micro-dissected tissues at the host-parasite interface to uncover details of the largely uncharacterized interaction between parasitic plants and their hosts. Results The interaction of Triphysaria with the distantly related hosts Zea mays and Medicago truncatula reveals dramatic host-specific gene expression patterns. Relative to above ground tissues, gene families are disproportionally represented at the interface including enrichment for transcription factors and genes of unknown function. Quantitative Real-Time PCR of a T. versicolor β-expansin shows strong differential (120x) upregulation in response to the monocot host Z. mays; a result that is concordant with our read count estimates. Pathogenesis-related proteins, other cell wall modifying enzymes, and orthologs of genes with unknown function (annotated as such in sequenced plant genomes) are among the parasite genes highly expressed by T. versicolor at the parasite-host interface. Conclusions Laser capture microdissection makes it possible to sample the small region of cells at the epicenter of parasite host interactions. The results of our analysis suggest that T. versicolor’s generalist strategy involves a reliance on overlapping but distinct gene sets, depending upon the host plant it is parasitizing. The massive upregulation of a T. versicolor β-expansin is suggestive of a mechanism for parasite success on grass hosts. In this preliminary study of the interface transcriptomes, we have shown that T. versicolor, and the Orobanchaceae in general, provide excellent opportunities for the

  1. Identification of a Divergent Environmental DNA Sequence Clade Using the Phylogeny of Gregarine Parasites (Apicomplexa) from Crustacean Hosts

    PubMed Central

    Rueckert, Sonja; Simdyanov, Timur G.; Aleoshin, Vladimir V.; Leander, Brian S.

    2011-01-01

    Background Environmental SSU rDNA surveys have significantly improved our understanding of microeukaryotic diversity. Many of the sequences acquired using this approach are closely related to lineages previously characterized at both morphological and molecular levels, making interpretation of these data relatively straightforward. Some sequences, by contrast, appear to be phylogenetic orphans and are sometimes inferred to represent “novel lineages” of unknown cellular identity. Consequently, interpretation of environmental DNA surveys of cellular diversity rely on an adequately comprehensive database of DNA sequences derived from identified species. Several major taxa of microeukaryotes, however, are still very poorly represented in these databases, and this is especially true for diverse groups of single-celled parasites, such as gregarine apicomplexans. Methodology/Principal Findings This study attempts to address this paucity of DNA sequence data by characterizing four different gregarine species, isolated from the intestines of crustaceans, at both morphological and molecular levels: Thiriotia pugettiae sp. n. from the graceful kelp crab (Pugettia gracilis), Cephaloidophora cf. communis from two different species of barnacles (Balanus glandula and B. balanus), Heliospora cf. longissima from two different species of freshwater amphipods (Eulimnogammarus verrucosus and E. vittatus), and Heliospora caprellae comb. n. from a skeleton shrimp (Caprella alaskana). SSU rDNA sequences were acquired from isolates of these gregarine species and added to a global apicomplexan alignment containing all major groups of gregarines characterized so far. Molecular phylogenetic analyses of these data demonstrated that all of the gregarines collected from crustacean hosts formed a very strongly supported clade with 48 previously unidentified environmental DNA sequences. Conclusions/Significance This expanded molecular phylogenetic context enabled us to establish a major clade

  2. The Effect of Parasite Infection on Stable Isotope Turnover Rates of δ15N, δ13C and δ34S in Multiple Tissues of Eurasian Perch Perca fluviatilis.

    PubMed

    Yohannes, Elizabeth; Grimm, Claudia; Rothhaupt, Karl-Otto; Behrmann-Godel, Jasminca

    2017-01-01

    Stable isotope analysis of commercially and ecologically important fish can improve understanding of life-history and trophic ecology. However, accurate interpretation of stable isotope values requires knowledge of tissue-specific isotopic turnover that will help to describe differences in the isotopic composition of tissues and diet. We performed a diet-switch experiment using captive-reared parasite-free Eurasian perch (Perca fluviatilis) and wild caught specimens of the same species, infected with the pike tapeworm Triaenophorus nodulosus living in host liver tissue. We hypothesize that metabolic processes related to infection status play a major role in isotopic turnover and examined the influence of parasite infection on isotopic turn-over rate of carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) in liver, blood and muscle. The δ15N and δ13C turnovers were fastest in liver tissues, followed by blood and muscle. In infected fish, liver and blood δ15N and δ13C turnover rates were similar. However, in infected fish, liver and blood δ13C turnover was faster than that of δ15N. Moreover, in infected subjects, liver δ15N and δ13C turnover rates were three to five times faster than in livers of uninfected subjects (isotopic half-life of ca.3-4 days compared to 16 and 10 days, respectively). Blood δ34S turnover rate were about twice faster in non-infected individuals implying that parasite infection could retard the turnover rate of δ34S and sulphur containing amino acids. Slower turnover rate of essential amino acid could probably decrease individual immune function. These indicate potential hidden costs of chronic and persistent infections that may have accumulated adverse effects and might eventually impair life-history fitness. For the first time, we were able to shift the isotope values of parasites encapsulated in the liver by changing the dietary source of the host. We also report variability in isotopic turnover rates between tissues, elements and

  3. The Effect of Parasite Infection on Stable Isotope Turnover Rates of δ15N, δ13C and δ34S in Multiple Tissues of Eurasian Perch Perca fluviatilis

    PubMed Central

    Yohannes, Elizabeth; Grimm, Claudia; Rothhaupt, Karl-Otto; Behrmann-Godel, Jasminca

    2017-01-01

    Stable isotope analysis of commercially and ecologically important fish can improve understanding of life-history and trophic ecology. However, accurate interpretation of stable isotope values requires knowledge of tissue-specific isotopic turnover that will help to describe differences in the isotopic composition of tissues and diet. We performed a diet-switch experiment using captive-reared parasite-free Eurasian perch (Perca fluviatilis) and wild caught specimens of the same species, infected with the pike tapeworm Triaenophorus nodulosus living in host liver tissue. We hypothesize that metabolic processes related to infection status play a major role in isotopic turnover and examined the influence of parasite infection on isotopic turn-over rate of carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) in liver, blood and muscle. The δ15N and δ13C turnovers were fastest in liver tissues, followed by blood and muscle. In infected fish, liver and blood δ15N and δ13C turnover rates were similar. However, in infected fish, liver and blood δ13C turnover was faster than that of δ15N. Moreover, in infected subjects, liver δ15N and δ13C turnover rates were three to five times faster than in livers of uninfected subjects (isotopic half-life of ca.3-4 days compared to 16 and 10 days, respectively). Blood δ34S turnover rate were about twice faster in non-infected individuals implying that parasite infection could retard the turnover rate of δ34S and sulphur containing amino acids. Slower turnover rate of essential amino acid could probably decrease individual immune function. These indicate potential hidden costs of chronic and persistent infections that may have accumulated adverse effects and might eventually impair life-history fitness. For the first time, we were able to shift the isotope values of parasites encapsulated in the liver by changing the dietary source of the host. We also report variability in isotopic turnover rates between tissues, elements and

  4. Life-cycle, ultrastructure, and phylogeny of Parvilucifera corolla sp. nov. (Alveolata, Perkinsozoa), a parasitoid of dinoflagellates.

    PubMed

    Reñé, Albert; Alacid, Elisabet; Figueroa, Rosa Isabel; Rodríguez, Francisco; Garcés, Esther

    2017-04-01

    Recent studies of marine protists have revealed parasites to be key components of marine communities. Here we describe a new species of the parasitoid genus Parvilucifera that was observed infecting the dinoflagellate Durinskia baltica in salt marshes of the Catalan coast (NW Mediterranean). In parallel, the same species was detected after the incubation of seawater from the Canary Islands (Lanzarote, NE Atlantic). The successful isolation of strains from both localities allowed description of the life cycle, ultrastructure, and phylogeny of the species. Its infection mechanism consists of a free-living zoospore that penetrates a dinoflagellate cell. The resulting trophont gradually degrades the dinoflagellate cytoplasm while growing in size. Once the host is consumed, schizogony of the parasitoid yields a sporocyte. After cytokinesis is complete, the newly formed zoospores are released into the environment and are ready to infect new host cells. A distinguishing feature of the species is the radial arrangement of its zoospores around the central area of the sporocyte during their formation. The species shows a close morphological similarity with other species of the genus, including P. infectans, P. sinerae, and P. rostrata. Copyright © 2016 Elsevier GmbH. All rights reserved.

  5. Northeast India Helminth Parasite Information Database (NEIHPID): Knowledge Base for Helminth Parasites.

    PubMed

    Biswal, Devendra Kumar; Debnath, Manish; Kharumnuid, Graciously; Thongnibah, Welfrank; Tandon, Veena

    2016-01-01

    Most metazoan parasites that invade vertebrate hosts belong to three phyla: Platyhelminthes, Nematoda and Acanthocephala. Many of the parasitic members of these phyla are collectively known as helminths and are causative agents of many debilitating, deforming and lethal diseases of humans and animals. The North-East India Helminth Parasite Information Database (NEIHPID) project aimed to document and characterise the spectrum of helminth parasites in the north-eastern region of India, providing host, geographical distribution, diagnostic characters and image data. The morphology-based taxonomic data are supplemented with information on DNA sequences of nuclear, ribosomal and mitochondrial gene marker regions that aid in parasite identification. In addition, the database contains raw next generation sequencing (NGS) data for 3 foodborne trematode parasites, with more to follow. The database will also provide study material for students interested in parasite biology. Users can search the database at various taxonomic levels (phylum, class, order, superfamily, family, genus, and species), or by host, habitat and geographical location. Specimen collection locations are noted as co-ordinates in a MySQL database and can be viewed on Google maps, using Google Maps JavaScript API v3. The NEIHPID database has been made freely available at http://nepiac.nehu.ac.in/index.php.

  6. Northeast India Helminth Parasite Information Database (NEIHPID): Knowledge Base for Helminth Parasites

    PubMed Central

    Debnath, Manish; Kharumnuid, Graciously; Thongnibah, Welfrank; Tandon, Veena

    2016-01-01

    Most metazoan parasites that invade vertebrate hosts belong to three phyla: Platyhelminthes, Nematoda and Acanthocephala. Many of the parasitic members of these phyla are collectively known as helminths and are causative agents of many debilitating, deforming and lethal diseases of humans and animals. The North-East India Helminth Parasite Information Database (NEIHPID) project aimed to document and characterise the spectrum of helminth parasites in the north-eastern region of India, providing host, geographical distribution, diagnostic characters and image data. The morphology-based taxonomic data are supplemented with information on DNA sequences of nuclear, ribosomal and mitochondrial gene marker regions that aid in parasite identification. In addition, the database contains raw next generation sequencing (NGS) data for 3 foodborne trematode parasites, with more to follow. The database will also provide study material for students interested in parasite biology. Users can search the database at various taxonomic levels (phylum, class, order, superfamily, family, genus, and species), or by host, habitat and geographical location. Specimen collection locations are noted as co-ordinates in a MySQL database and can be viewed on Google maps, using Google Maps JavaScript API v3. The NEIHPID database has been made freely available at http://nepiac.nehu.ac.in/index.php PMID:27285615

  7. Why do morphological phylogenies vary in quality? An investigation based on the comparative history of lizard clades.

    PubMed

    Arnold, E N

    1990-05-22

    Phylogenies based on morphology vary considerably in their quality: some are robust and explicit with little conflict in the data set, whereas others are far more tenuous, with much conflict and many possible alternatives. The main primary reasons for untrue or inexplicit morphological phylogenies are: not enough characters developed between branching points, uncertain character polarity, poorly differentiated character states, homoplasy caused by parallelism or reversal, and extinction, which may remove species entirely from consideration and can make originally conflicting data sets misleadingly compatible, increasing congruence at the expense of truth. Extinction differs from other confounding factors in not being apparent either in the data set or in subsequent analysis. One possibility is that variation in the quality of morphological phylogenies has resulted from exposure to different ecological situations. To investigate this, it is necessary to compare the histories of the clades concerned. In the case of explicit morphological phylogenies, ecological and behavioural data can be integrated with them and it may then be possible to decide whether morphological characters are likely to have been elicited by the environments through which the clade has passed. The credibility of such results depends not only on the phylogeny being robust but also on its detailed topology: a pectinate phylogeny will often allow more certain and more explicit statements to be made about historical events. In the case of poor phylogenies, it is not possible to produce detailed histories, but they can be compared with robust phylogenies in the range of ecological situations occupied, and whether they occupy novel situations in comparison with their outgroups. LeQuesne testing can give information about niche homoplasy, and it may also be possible to see if morphological features are functionally associated with ecological parameters, even if the direction of change is unknown

  8. Molecular evidence for host-parasite co-speciation between lizards and Schellackia parasites.

    PubMed

    Megía-Palma, Rodrigo; Martínez, Javier; Cuervo, José J; Belliure, Josabel; Jiménez-Robles, Octavio; Gomes, Verónica; Cabido, Carlos; Pausas, Juli G; Fitze, Patrick S; Martín, José; Merino, Santiago

    2018-05-05

    Current and past parasite transmission may depend on the overlap of host distributions, potentially affecting parasite specificity and co-evolutionary processes. Nonetheless, parasite diversification may take place in sympatry when parasites are transmitted by vectors with low mobility. Here, we test the co-speciation hypothesis between lizard final hosts of the Family Lacertidae, and blood parasites of the genus Schellackia, which are potentially transmitted by haematophagous mites. The effects of current distributional overlap of host species on parasite specificity are also investigated. We sampled 27 localities on the Iberian Peninsula and three in northern Africa, and collected blood samples from 981 individual lizards of seven genera and 18 species. The overall prevalence of infection by parasites of the genus Schellackia was ∼35%. We detected 16 Schellackia haplotypes of the 18S rRNA gene, revealing that the genus Schellackia is more diverse than previously thought. Phylogenetic analyses showed that Schellackia haplotypes grouped into two main monophyletic clades, the first including those detected in host species endemic to the Mediterranean region and the second those detected in host genera Acanthodactylus, Zootoca and Takydromus. All but one of the Schellackia haplotypes exhibited a high degree of host specificity at the generic level and 78.5% of them exclusively infected single host species. Some host species within the genera Podarcis (six species) and Iberolacerta (two species) were infected by three non-specific haplotypes of Schellackia, suggesting that host switching might have positively influenced past diversification of the genus. However, the results supported the idea that current host switching is rare because there existed a significant positive correlation between the number of exclusive parasite haplotypes and the number of host species with current sympatric distribution. This result, together with significant support for host-parasite

  9. Peroxiredoxins in Parasites

    PubMed Central

    Gretes, Michael C.; Poole, Leslie B.

    2012-01-01

    Abstract Significance: Parasite survival and virulence relies on effective defenses against reactive oxygen and nitrogen species produced by the host immune system. Peroxiredoxins (Prxs) are ubiquitous enzymes now thought to be central to such defenses and, as such, have potential value as drug targets and vaccine antigens. Recent Advances: Plasmodial and kinetoplastid Prx systems are the most extensively studied, yet remain inadequately understood. For many other parasites our knowledge is even less well developed. Through parasite genome sequencing efforts, however, the key players are being discovered and characterized. Here we describe what is known about the biochemistry, regulation, and cell biology of Prxs in parasitic protozoa, helminths, and fungi. At least one Prx is found in each parasite with a sequenced genome, and a notable theme is the common patterns of expression, localization, and functionality among sequence-similar Prxs in related species. Critical Issues: The nomenclature of Prxs from parasites is in a state of disarray, causing confusion and making comparative inferences difficult. Here we introduce a systematic Prx naming convention that is consistent between organisms and informative about structural and evolutionary relationships. Future Directions: The new nomenclature should stimulate the crossfertilization of ideas among parasitologists and with the broader redox research community. The diverse parasite developmental stages and host environments present complex systems in which to explore the variety of roles played by Prxs, with a view toward parlaying what is learned into novel therapies and vaccines that are urgently needed. Antioxid. Redox Signal. 17, 608–633. PMID:22098136

  10. Phylogeny of the túngara frog genus Engystomops (= Physalaemus pustulosus species group; Anura: Leptodactylidae).

    PubMed

    Ron, Santiago R; Santos, Juan C; Cannatella, David C

    2006-05-01

    We present a phylogeny of the Neotropical genus Engystomops (= Physalaemus pustulosus species group) based on sequences of approximately 2.4 kb of mtDNA, (12S rRNA, valine-tRNA, and 16S rRNA) and propose a phylogenetic nomenclature. The phylogeny includes all described taxa and two unnamed species. All analyses indicate that Engystomops is monophyletic and contains two basal allopatric clades. Clade I (Edentulus) includes E. pustulosus and the Amazonian E. petersi + E. cf. freibergi. Clade II (Duovox) includes all species distributed in W Ecuador and NW Peru. Brevivox, a clade of small-sized species is strongly supported within Duovox. Populations of Engystomops pustulosus fall into two well-supported clades, each of which occupies two disjunct portions of the species range. Overall, our phylogeny is congruent with most previous hypotheses. This study is among the few published species-level phylogenies of Neotropical amphibians derived from molecular datasets. A review of the proportion of new species detected by similar studies suggests that the increasing use of molecular techniques will lead to the discovery of a vast number of species of Neotropical amphibians.

  11. Phylogenetic analysis of apicomplexan parasites infecting commercially valuable species from the North-East Atlantic reveals high levels of diversity and insights into the evolution of the group.

    PubMed

    Xavier, Raquel; Severino, Ricardo; Pérez-Losada, Marcos; Gestal, Camino; Freitas, Rita; Harris, D James; Veríssimo, Ana; Rosado, Daniela; Cable, Joanne

    2018-01-25

    The Apicomplexa from aquatic environments are understudied relative to their terrestrial counterparts, and the seminal work assessing the phylogenetic relations of fish-infecting lineages is mostly based on freshwater hosts. The taxonomic uncertainty of some apicomplexan groups, such as the coccidia, is high and many genera were recently shown to be paraphyletic, questioning the value of strict morphological and ecological traits for parasite classification. Here, we surveyed the genetic diversity of the Apicomplexa in several commercially valuable vertebrates from the North-East Atlantic, including farmed fish. Most of the sequences retrieved were closely related to common fish coccidia of Eimeria, Goussia and Calyptospora. However, some lineages from the shark Scyliorhinus canicula were placed as sister taxa to the Isospora, Caryospora and Schellakia group. Additionally, others from Pagrus caeruleostictus and Solea senegalensis belonged to an unknown apicomplexan group previously found in the Caribbean Sea, where it was sequenced from the water column, corals, and fish. Four distinct parasite lineages were found infecting farmed Dicentrarchus labrax or Sparus aurata. One of the lineages from farmed D. labrax was also found infecting wild counterparts, and another was also recovered from farmed S. aurata and farm-associated Diplodus sargus. Our results show that marine fish apicomplexans are diverse, and we highlight the need for a more extensive assessment of parasite diversity in this phylum. Additionally, parasites recovered from S. canicula were recovered as basal to their piscine counterparts reflecting hosts phylogeny.

  12. Phylogeny and temporal diversification of darters (Percidae: Etheostomatinae).

    PubMed

    Near, Thomas J; Bossu, Christen M; Bradburd, Gideon S; Carlson, Rose L; Harrington, Richard C; Hollingsworth, Phillip R; Keck, Benjamin P; Etnier, David A

    2011-10-01

    Discussions aimed at resolution of the Tree of Life are most often focused on the interrelationships of major organismal lineages. In this study, we focus on the resolution of some of the most apical branches in the Tree of Life through exploration of the phylogenetic relationships of darters, a species-rich clade of North American freshwater fishes. With a near-complete taxon sampling of close to 250 species, we aim to investigate strategies for efficient multilocus data sampling and the estimation of divergence times using relaxed-clock methods when a clade lacks a fossil record. Our phylogenetic data set comprises a single mitochondrial DNA (mtDNA) gene and two nuclear genes sampled from 245 of the 248 darter species. This dense sampling allows us to determine if a modest amount of nuclear DNA sequence data can resolve relationships among closely related animal species. Darters lack a fossil record to provide age calibration priors in relaxed-clock analyses. Therefore, we use a near-complete species-sampled phylogeny of the perciform clade Centrarchidae, which has a rich fossil record, to assess two distinct strategies of external calibration in relaxed-clock divergence time estimates of darters: using ages inferred from the fossil record and molecular evolutionary rate estimates. Comparison of Bayesian phylogenies inferred from mtDNA and nuclear genes reveals that heterospecific mtDNA is present in approximately 12.5% of all darter species. We identify three patterns of mtDNA introgression in darters: proximal mtDNA transfer, which involves the transfer of mtDNA among extant and sympatric darter species, indeterminate introgression, which involves the transfer of mtDNA from a lineage that cannot be confidently identified because the introgressed haplotypes are not clearly referable to mtDNA haplotypes in any recognized species, and deep introgression, which is characterized by species diversification within a recipient clade subsequent to the transfer of

  13. Molecular identification of Taenia serialis coenurosis in a wild Ethiopian gelada (Theropithecus gelada).

    PubMed

    Schneider-Crease, India A; Snyder-Mackler, Noah; Jarvey, Julie C; Bergman, Thore J

    2013-11-15

    Since morphological identification of a larval Taeniid in geladas (Theropithecus gelada) has produced inconsistent results, genetic information is pivotal for species identification. Nuclear and mitochondrial DNA from a coenurus in a wild gelada were compared to published sequences from multiple Taeniid species, confirming the identification of this parasite as Taenia serialis. A demographic analysis finds age to be a strong predictor of coenuri. Tapeworms rarely employ primates as intermediate hosts, and the presence of T. serialis in a wild gelada population may indicate a substantial ecological shift in this parasite's life cycle. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. [Main evolution lines of plant parasitic nematodes of the order Aphelenchida siddiqi, 1980].

    PubMed

    Ryss, A Iu

    2007-01-01

    Phylogenic models for each aphelenchid family and phylogeny of the order Aphelenchida as a whole were developed on the base of detailed comparative morphological and bionomical analysis of the order. Bionomical and morphological characters having a phylogenetic significance were selected. Classification proposed by Hunt, 1993 was used as the starting-point of the study. Life cycles and their evolution in Aphelenchida were analyzed on the base of phylogenetic trees. It is concluded, that aphelenchid ancestors combined mycophagy, plant parasitic, and partly predaceous feeding. Relations of the primitive Aphelenchida with their symbionts developed from the spots of the fungal organic matter decomposition in the "nema- tode-fungi" associations, followed by a transition to the temporary endoparasitic habit omitting ectoparasitism. With a complication of the nematodes' life cycles, the insect vector (detritophagous or pollinator) transformed into the real insect host of the parasitic nematode in the 2-host life cycle (with the plant and insect hosts) or in the obligate 1-host entomoparasitic life cycle of the aphelenchid nematodes. Specialization of the aphelenchid life cycles to insect vectors followed two main ways. In the first way, the resistant to unfavorable environmental conditions nematode juveniles, known already for the primitive aphelenchids transformed into dispersal juveniles, and later into parasitic juveniles. In the second evolution line the dispersal function were laid on inseminated but non-gravid (not egg-producing) females. Both above-mentioned trends of parasitic specialization were arisen independently in different phylogenetic lines of the Aphelenchida. In each line of the parasitic development in different nematode families, the highly specialized ectoparasites, as well as endoparasites on insects, were formed. In the evolution of life cycle of parasitic nematodes, a tendency to decrease the body size took place. The function of dispersion shifted

  15. Codiversification of gastrointestinal microbiota and phylogeny in passerines is not explained by ecological divergence.

    PubMed

    Kropáčková, Lucie; Těšický, Martin; Albrecht, Tomáš; Kubovčiak, Jan; Čížková, Dagmar; Tomášek, Oldřich; Martin, Jean-François; Bobek, Lukáš; Králová, Tereza; Procházka, Petr; Kreisinger, Jakub

    2017-10-01

    Vertebrate gut microbiota (GM) is comprised of a taxonomically diverse consortium of symbiotic and commensal microorganisms that have a pronounced effect on host physiology, immune system function and health status. Despite much research on interactions between hosts and their GM, the factors affecting inter- and intraspecific GM variation in wild populations are still poorly known. We analysed data on faecal microbiota composition in 51 passerine species (319 individuals) using Illumina MiSeq sequencing of bacterial 16S rRNA (V3-V4 variable region). Despite pronounced interindividual variation, GM composition exhibited significant differences at the interspecific level, accounting for approximately 20%-30% of total GM variation. We also observed a significant correlation between GM composition divergence and host's phylogenetic divergence, with strength of correlation higher than that of GM vs. ecological or life history traits and geographic variation. The effect of host's phylogeny on GM composition was significant, even after statistical control for these confounding factors. Hence, our data do not support codiversification of GM and passerine phylogeny solely as a by-product of their ecological divergence. Furthermore, our findings do not support that GM vs. host's phylogeny codiversification is driven primarily through trans-generational GM transfer as the GM vs. phylogeny correlation does not increase with higher sequence similarity used when delimiting operational taxonomic units. Instead, we hypothesize that the GM vs. phylogeny correlation may arise as a consequence of interspecific divergence of genes that directly or indirectly modulate composition of GM. © 2017 John Wiley & Sons Ltd.

  16. Extracellular vesicles in parasitic diseases

    PubMed Central

    Marcilla, Antonio; Martin-Jaular, Lorena; Trelis, Maria; de Menezes-Neto, Armando; Osuna, Antonio; Bernal, Dolores; Fernandez-Becerra, Carmen; Almeida, Igor C.; del Portillo, Hernando A.

    2014-01-01

    Parasitic diseases affect billions of people and are considered a major public health issue. Close to 400 species are estimated to parasitize humans, of which around 90 are responsible for great clinical burden and mortality rates. Unfortunately, they are largely neglected as they are mainly endemic to poor regions. Of relevance to this review, there is accumulating evidence of the release of extracellular vesicles (EVs) in parasitic diseases, acting both in parasite–parasite inter-communication as well as in parasite–host interactions. EVs participate in the dissemination of the pathogen and play a role in the regulation of the host immune systems. Production of EVs from parasites or parasitized cells has been described for a number of parasitic infections. In this review, we provide the most relevant findings of the involvement of EVs in intercellular communication, modulation of immune responses, involvement in pathology, and their potential as new diagnostic tools and therapeutic agents in some of the major human parasitic pathogens. PMID:25536932

  17. Synthesis of phylogeny and taxonomy into a comprehensive tree of life.

    PubMed

    Hinchliff, Cody E; Smith, Stephen A; Allman, James F; Burleigh, J Gordon; Chaudhary, Ruchi; Coghill, Lyndon M; Crandall, Keith A; Deng, Jiabin; Drew, Bryan T; Gazis, Romina; Gude, Karl; Hibbett, David S; Katz, Laura A; Laughinghouse, H Dail; McTavish, Emily Jane; Midford, Peter E; Owen, Christopher L; Ree, Richard H; Rees, Jonathan A; Soltis, Douglas E; Williams, Tiffani; Cranston, Karen A

    2015-10-13

    Reconstructing the phylogenetic relationships that unite all lineages (the tree of life) is a grand challenge. The paucity of homologous character data across disparately related lineages currently renders direct phylogenetic inference untenable. To reconstruct a comprehensive tree of life, we therefore synthesized published phylogenies, together with taxonomic classifications for taxa never incorporated into a phylogeny. We present a draft tree containing 2.3 million tips-the Open Tree of Life. Realization of this tree required the assembly of two additional community resources: (i) a comprehensive global reference taxonomy and (ii) a database of published phylogenetic trees mapped to this taxonomy. Our open source framework facilitates community comment and contribution, enabling the tree to be continuously updated when new phylogenetic and taxonomic data become digitally available. Although data coverage and phylogenetic conflict across the Open Tree of Life illuminate gaps in both the underlying data available for phylogenetic reconstruction and the publication of trees as digital objects, the tree provides a compelling starting point for community contribution. This comprehensive tree will fuel fundamental research on the nature of biological diversity, ultimately providing up-to-date phylogenies for downstream applications in comparative biology, ecology, conservation biology, climate change, agriculture, and genomics.

  18. Higher-level phylogeny of paraneopteran insects inferred from mitochondrial genome sequences

    PubMed Central

    Li, Hu; Shao, Renfu; Song, Nan; Song, Fan; Jiang, Pei; Li, Zhihong; Cai, Wanzhi

    2015-01-01

    Mitochondrial (mt) genome data have been proven to be informative for animal phylogenetic studies but may also suffer from systematic errors, due to the effects of accelerated substitution rate and compositional heterogeneity. We analyzed the mt genomes of 25 insect species from the four paraneopteran orders, aiming to better understand how accelerated substitution rate and compositional heterogeneity affect the inferences of the higher-level phylogeny of this diverse group of hemimetabolous insects. We found substantial heterogeneity in base composition and contrasting rates in nucleotide substitution among these paraneopteran insects, which complicate the inference of higher-level phylogeny. The phylogenies inferred with concatenated sequences of mt genes using maximum likelihood and Bayesian methods and homogeneous models failed to recover Psocodea and Hemiptera as monophyletic groups but grouped, instead, the taxa that had accelerated substitution rates together, including Sternorrhyncha (a suborder of Hemiptera), Thysanoptera, Phthiraptera and Liposcelididae (a family of Psocoptera). Bayesian inference with nucleotide sequences and heterogeneous models (CAT and CAT + GTR), however, recovered Psocodea, Thysanoptera and Hemiptera each as a monophyletic group. Within Psocodea, Liposcelididae is more closely related to Phthiraptera than to other species of Psocoptera. Furthermore, Thysanoptera was recovered as the sister group to Hemiptera. PMID:25704094

  19. A fungal phylogeny based on 42 complete genomes derived from supertree and combined gene analysis

    PubMed Central

    Fitzpatrick, David A; Logue, Mary E; Stajich, Jason E; Butler, Geraldine

    2006-01-01

    Background To date, most fungal phylogenies have been derived from single gene comparisons, or from concatenated alignments of a small number of genes. The increase in fungal genome sequencing presents an opportunity to reconstruct evolutionary events using entire genomes. As a tool for future comparative, phylogenomic and phylogenetic studies, we used both supertrees and concatenated alignments to infer relationships between 42 species of fungi for which complete genome sequences are available. Results A dataset of 345,829 genes was extracted from 42 publicly available fungal genomes. Supertree methods were employed to derive phylogenies from 4,805 single gene families. We found that the average consensus supertree method may suffer from long-branch attraction artifacts, while matrix representation with parsimony (MRP) appears to be immune from these. A genome phylogeny was also reconstructed from a concatenated alignment of 153 universally distributed orthologs. Our MRP supertree and concatenated phylogeny are highly congruent. Within the Ascomycota, the sub-phyla Pezizomycotina and Saccharomycotina were resolved. Both phylogenies infer that the Leotiomycetes are the closest sister group to the Sordariomycetes. There is some ambiguity regarding the placement of Stagonospora nodurum, the sole member of the class Dothideomycetes present in the dataset. Within the Saccharomycotina, a monophyletic clade containing organisms that translate CTG as serine instead of leucine is evident. There is also strong support for two groups within the CTG clade, one containing the fully sexual species Candida lusitaniae, Candida guilliermondii and Debaryomyces hansenii, and the second group containing Candida albicans, Candida dubliniensis, Candida tropicalis, Candida parapsilosis and Lodderomyces elongisporus. The second major clade within the Saccharomycotina contains species whose genomes have undergone a whole genome duplication (WGD), and their close relatives. We could not

  20. 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.

  1. 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

  2. Protein moonlighting in parasitic protists.

    PubMed

    Ginger, Michael L

    2014-12-01

    Reductive evolution during the adaptation to obligate parasitism and expansions of gene families encoding virulence factors are characteristics evident to greater or lesser degrees in all parasitic protists studied to date. Large evolutionary distances separate many parasitic protists from the yeast and animal models upon which classic views of eukaryotic biochemistry are often based. Thus a combination of evolutionary divergence, niche adaptation and reductive evolution means the biochemistry of parasitic protists is often very different from their hosts and to other eukaryotes generally, making parasites intriguing subjects for those interested in the phenomenon of moonlighting proteins. In common with other organisms, the contribution of protein moonlighting to parasite biology is only just emerging, and it is not without controversy. Here, an overview of recently identified moonlighting proteins in parasitic protists is provided, together with discussion of some of the controversies.

  3. It's a predator-eat-parasite world: how characteristics of predator, parasite and environment affect consumption.

    PubMed

    Orlofske, Sarah A; Jadin, Robert C; Johnson, Pieter T J

    2015-06-01

    Understanding the effects of predation on disease dynamics is increasingly important in light of the role ecological communities can play in host-parasite interactions. Surprisingly, however, few studies have characterized direct predation of parasites. Here we used an experimental approach to show that consumption of free-living parasite stages is highly context dependent, with significant influences of parasite size, predator size and foraging mode, as well as environmental condition. Among the four species of larval trematodes and two types of predators (fish and larval damselflies) studied here, parasites with larger infective stages (size >1,000 μm) were most vulnerable to predation by fish, while small-bodied fish and damselflies (size <10 mm) consumed the most infectious stages. Small parasite species (size approx. 500 μm) were less frequently consumed by both fish and larval damselflies. However, these results depended strongly on light availability; trials conducted in the dark led to significantly fewer parasites consumed overall, especially those with a size of <1,000 μm, emphasizing the importance of circadian shedding times of parasite free-living stages for predation risk. Intriguingly, active predation functioned to help limit fishes' infection by directly penetrating parasite species. Our results are consistent with established theory developed for predation on zooplankton that emphasizes the roles of body size, visibility and predation modes and further suggest that consumer-resource theory may provide a predictive framework for when predators should significantly influence parasite transmission. These results contribute to our understanding of transmission in natural systems, the role of predator-parasite links in food webs and the evolution of parasite morphology and behavior.

  4. A plastid gene phylogeny of the non-photosynthetic parasitic Orobanche (Orobanchaceae) and related genera

    USGS Publications Warehouse

    Park, J.-M.; Manen, J.-F.; Colwell, A.E.; Schneeweiss, G.M.

    2008-01-01

    The phylogenetic relationships of the non-photosynthetic Orobanche sensu lato (Orobanchaceae), which includes some of the economically most important parasitic weeds, remain insufficiently understood and controversial. This concerns both the phylogenetic relationships within the genus, in particular its monophyly or lack thereof, and the relationships to other holoparasitic genera such as Cistanche or Conopholis. Here we present the first comprehensive phylogenetic study of this group based on a region from the plastid genome (rps2 gene). Although substitution rates appear to be elevated compared to the photosynthetic members of Orobanchaceae, relationships among the major lineages Cistanche, Conopholis plus Epifagus, Boschniakia rossica (Cham. & Schltdl.) B. Fedtsch., B. himalaica Hook. f. & Thomson, B. hookeri Walp. plus B. strobilacea A. Gray, and Orobanche s. l. remain unresolved. Resolution within Orobanche, however, is much better. In agreement with morphological, cytological and other molecular phylogenetic evidence, five lineages, corresponding to the four traditionally recognised sections (Gymnocaulis, Myzorrhiza, Orobanche, Trionychon) and O. latisquama Reut. ex Boiss. (of sect. Orobanche), can be distinguished. A combined analysis of plastid rps2 and nuclear ITS sequences of the holoparasitic genera results in more resolved and better supported trees, although the relationships among Orobanche s. l., Cistanche, and the clade including the remaining genera is unresolved. Therefore, rps2 is a marker from the plastid genome that is well-suited to be used in combination with other already established nuclear markers for resolving generic relationships of Orobanche and related genera. ?? 2008 The Botanical Society of Japan and Springer.

  5. Phylogeny Inference of Closely Related Bacterial Genomes: Combining the Features of Both Overlapping Genes and Collinear Genomic Regions

    PubMed Central

    Zhang, Yan-Cong; Lin, Kui

    2015-01-01

    Overlapping genes (OGs) represent one type of widespread genomic feature in bacterial genomes and have been used as rare genomic markers in phylogeny inference of closely related bacterial species. However, the inference may experience a decrease in performance for phylogenomic analysis of too closely or too distantly related genomes. Another drawback of OGs as phylogenetic markers is that they usually take little account of the effects of genomic rearrangement on the similarity estimation, such as intra-chromosome/genome translocations, horizontal gene transfer, and gene losses. To explore such effects on the accuracy of phylogeny reconstruction, we combine phylogenetic signals of OGs with collinear genomic regions, here called locally collinear blocks (LCBs). By putting these together, we refine our previous metric of pairwise similarity between two closely related bacterial genomes. As a case study, we used this new method to reconstruct the phylogenies of 88 Enterobacteriale genomes of the class Gammaproteobacteria. Our results demonstrated that the topological accuracy of the inferred phylogeny was improved when both OGs and LCBs were simultaneously considered, suggesting that combining these two phylogenetic markers may reduce, to some extent, the influence of gene loss on phylogeny inference. Such phylogenomic studies, we believe, will help us to explore a more effective approach to increasing the robustness of phylogeny reconstruction of closely related bacterial organisms. PMID:26715828

  6. Multilocus resolution of Mugilidae phylogeny (Teleostei: Mugiliformes): Implications for the family's taxonomy.

    PubMed

    Xia, Rong; Durand, Jean-Dominique; Fu, Cuizhang

    2016-03-01

    The interrelationships among mugilids (Mugiliformes: Mugilidae) remain highly debated. Using a mitochondrial gene-based phylogeny as criterion, a revised classification with 25 genera in the Mugilidae has recently been proposed. However, phylogenetic relationships of major mitochondrial lineages remain unresolved and to gain a general acceptance the classification requires confirmation based on multilocus evidence and diagnostic morphological characters. Here, we construct a species-tree using twelve nuclear and three mitochondrial loci and infer the evolution of 71 morphological characters. Our multilocus phylogeny does not agree with previous morphology-based hypotheses for the relationships within Mugilidae, confirms the revised classification with 25 genera and further resolves their phylogenetic relationships. Using the well-resolved multilocus phylogeny as the criterion, we reclassify Mugilidae genera into three new subfamilies (Myxinae, Rhinomugilinae, and Cheloninae) and one new, recombined, subfamily (Mugilinae). The Rhinomugilinae subfamily is further divided into four tribes. The revised classification of Mugilidae is supported by morpho-anatomical synapomorphies or a combination of characters. These characters are used to erect a key to the subfamilies and genera. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Role of parasites in cancer.

    PubMed

    Mandong, B M; Ngbea, J A; Raymond, Vhriterhire

    2013-01-01

    In areas of parasitic endemicity, the occurrence of cancer that is not frequent may be linked with parasitic infection. Epidemiological correlates between some parasitic infections and cancer is strong, suggesting a strong aetiological association. The common parasites associated with human cancers are schistosomiasis, malaria, liver flukes (Clonorchis sinenses, Opistorchis viverrini). To review the pathology, literature and methods of diagnosis. Literature review from peer reviewed Journals cited in PubMed and local journals. Parasites may serve as promoters of cancer in endemic areas of infection.

  8. Parasite Removal, but Not Herbivory, Deters Future Parasite Attachment on Tomato

    PubMed Central

    Tjiurutue, Muvari Connie; Palmer-Young, Evan C.; Adler, Lynn S.

    2016-01-01

    Plants face many antagonistic interactions that occur sequentially. Often, plants employ defense strategies in response to the initial damage that are highly specific and can affect interactions with subsequent antagonists. In addition to herbivores and pathogens, plants face attacks by parasitic plants, but we know little about how prior herbivory compared to prior parasite attachment affects subsequent host interactions. If host plants can respond adaptively to these different damage types, we predict that prior parasitism would have a greater deterrent effect on subsequent parasites than would prior herbivory. To test the effects of prior parasitism and prior herbivory on subsequent parasitic dodder (Cuscuta spp.) preference, we conducted two separate greenhouse studies with tomato hosts (Solanum lycopersicum). In the first experiment, we tested the effects of previous dodder attachment on subsequent dodder preference on tomato hosts using three treatments: control plants that had no previous dodder attachment; dodder-removed plants that had an initial dodder seedling attached, removed and left in the same pot to simulate parasite death; and dodder-continuous plants with an initial dodder seedling that remained attached. In the second experiment, we tested the effects of previous caterpillar damage (Spodoptera exigua) and mechanical damage on future dodder attachment on tomato hosts. Dodder attached most slowly to tomato hosts that had dodder plants previously attached and then removed, compared to control plants or plants with continuous dodder attachment. In contrast, herbivory did not affect subsequent dodder attachment rate. These results indicate that dodder preference depended on the identity and the outcome of the initial attack, suggesting that early-season interactions have the potential for profound impacts on subsequent community dynamics. PMID:27529694

  9. Evolution of the protists and protistan parasites from the perspective of molecular systematics.

    PubMed

    Sogin, M L; Silberman, J D

    1998-01-01

    Unlike prokaryotes, the Protista are rich in morphological and ultrastructure information. Their amazing phenotypic diversity permits assignment of many protists to cohesive phyletic assemblages but sometimes blurs relationships between major lineages. With the advent of molecular techniques, it became possible to test evolutionary hypotheses that were originally formulated according to shared phenotypic traits. More than any other gene family, studies of rRNAs changed our understanding of protist evolution. Stramenopiles (oomycetes, chrysophytes, phaeophytes, synurophytes, diatoms, xanthophytes, bicosoecids, slime nets) and alveolates (dinoflagellates, apicomplexans, ciliates) are two novel, complex evolutionary assemblages which diverged nearly simultaneously with animals, fungi, plants, rhodophytes, haptophytes and a myriad of independent amoeboid lineages. Their separation may have occurred one billion years ago and collectively these lineages make up the "crown" of the eukaryotic tree. Deeper branches in the eukaryotic tree show 16S-like rRNA sequence variation that is much greater than that observed within the Archaea and the Bacteria. A progression of independent protist branches, some as ancient as the divergence between the two prokaryotic domains, preceded the sudden radiation of "crown" groups. Trichomonads, diplomonads and Microsporidia are basal to all other eukaryotes included in rRNA studies. Together with pelobionts, oxymonads, retortamonads and hypermastigids, these amitochondriate taxa comprise the Archaezoa. This skeletal phylogeny suggested that early branching eukaryotes lacked mitochondria, peroxisomes and typical stacked Golgi dictyosomes. However, recent studies of heat shock proteins indicate that the first eukaryotes may have had mitochondria. When evaluated in terms of evolution of ultrastructure, lifestyles and other phenotypic traits, the rRNA phylogenies provide the most consistent of molecular trees. They permit identification of the

  10. Infection by Dipylidium caninum in an infant.

    PubMed

    Molina, Claudia P; Ogburn, James; Adegboyega, Patrick

    2003-03-01

    Dipylidium caninum, the dog tapeworm, is a cosmopolitan parasite of dogs and cats and occasionally causes human infection in the United States. Diagnosis is made by observing the characteristic rice grain-like proglottids in stool specimens and the pathognomonic egg packets in the gravid uterus in histologic sections of the parasite. There have been few reported cases of human infection with this parasite, and very little information on the pathology of this zoonotic disease is available in the English language. This report of a case of D caninum infection in a 6-month-old infant highlights the diagnostic features of this disease. To our knowledge, this is the first case to be reported in the American pathology literature during the last 36 years (MEDLINE database, 1966-2002).

  11. Parasitism and the biodiversity-functioning relationship

    USGS Publications Warehouse

    Frainer, André; McKie, Brendan G.; Amundsen, Per-Arne; Knudsen, Rune; Lafferty, Kevin D.

    2018-01-01

    Biodiversity affects ecosystem functioning.Biodiversity may decrease or increase parasitism.Parasites impair individual hosts and affect their role in the ecosystem.Parasitism, in common with competition, facilitation, and predation, could regulate BD-EF relationships.Parasitism affects host phenotypes, including changes to host morphology, behavior, and physiology, which might increase intra- and interspecific functional diversity.The effects of parasitism on host abundance and phenotypes, and on interactions between hosts and the remaining community, all have potential to alter community structure and BD-EF relationships.Global change could facilitate the spread of invasive parasites, and alter the existing dynamics between parasites, communities, and ecosystems.Species interactions can influence ecosystem functioning by enhancing or suppressing the activities of species that drive ecosystem processes, or by causing changes in biodiversity. However, one important class of species interactions – parasitism – has been little considered in biodiversity and ecosystem functioning (BD-EF) research. Parasites might increase or decrease ecosystem processes by reducing host abundance. Parasites could also increase trait diversity by suppressing dominant species or by increasing within-host trait diversity. These different mechanisms by which parasites might affect ecosystem function pose challenges in predicting their net effects. Nonetheless, given the ubiquity of parasites, we propose that parasite–host interactions should be incorporated into the BD-EF framework.

  12. How Many Parasites Species a Frog Might Have? Determinants of Parasite Diversity in South American Anurans

    PubMed Central

    Campião, Karla Magalhães; Ribas, Augusto Cesar de Aquino; Morais, Drausio Honorio; da Silva, Reinaldo José; Tavares, Luiz Eduardo Roland

    2015-01-01

    There is an increasing interest in unveiling the dynamics of parasite infection. Understanding the interaction patterns, and determinants of host-parasite association contributes to filling knowledge gaps in both community and disease ecology. Despite being targeted as a relevant group for conservation efforts, determinants of the association of amphibians and their parasites in broad scales are poorly understood. Here we describe parasite biodiversity in South American amphibians, testing the influence of host body size and geographic range in helminth parasites species richness (PSR). We also test whether parasite diversity is related to hosts’ phylogenetic diversity. Results showed that nematodes are the most common anuran parasites. Host-parasite network has a nested pattern, with specialist helminth taxa generally associated with hosts that harbour the richest parasite faunas. Host size is positively correlated with helminth fauna richness, but we found no support for the association of host geographic range and PSR. These results remained consistent after correcting for uneven study effort and hosts’ phylogenic correlation. However, we found no association between host and parasite diversity, indicating that more diversified anuran clades not necessarily support higher parasite diversity. Overall, considering both the structure and the determinants of PRS in anurans, we conclude that specialist parasites are more likely to be associated with large anurans, which are the ones harbouring higher PSR, and that the lack of association of PSR with hosts’ clade diversification suggests it is strongly influenced by ecological and contemporary constrains. PMID:26473593

  13. How Many Parasites Species a Frog Might Have? Determinants of Parasite Diversity in South American Anurans.

    PubMed

    Campião, Karla Magalhães; Ribas, Augusto Cesar de Aquino; Morais, Drausio Honorio; da Silva, Reinaldo José; Tavares, Luiz Eduardo Roland

    2015-01-01

    There is an increasing interest in unveiling the dynamics of parasite infection. Understanding the interaction patterns, and determinants of host-parasite association contributes to filling knowledge gaps in both community and disease ecology. Despite being targeted as a relevant group for conservation efforts, determinants of the association of amphibians and their parasites in broad scales are poorly understood. Here we describe parasite biodiversity in South American amphibians, testing the influence of host body size and geographic range in helminth parasites species richness (PSR). We also test whether parasite diversity is related to hosts' phylogenetic diversity. Results showed that nematodes are the most common anuran parasites. Host-parasite network has a nested pattern, with specialist helminth taxa generally associated with hosts that harbour the richest parasite faunas. Host size is positively correlated with helminth fauna richness, but we found no support for the association of host geographic range and PSR. These results remained consistent after correcting for uneven study effort and hosts' phylogenic correlation. However, we found no association between host and parasite diversity, indicating that more diversified anuran clades not necessarily support higher parasite diversity. Overall, considering both the structure and the determinants of PRS in anurans, we conclude that specialist parasites are more likely to be associated with large anurans, which are the ones harbouring higher PSR, and that the lack of association of PSR with hosts' clade diversification suggests it is strongly influenced by ecological and contemporary constrains.

  14. Beringia: Intercontinental exchange and diversification of high latitude mammals and their parasites during the Pliocene and Quaternary

    USGS Publications Warehouse

    Cook, Joseph A.; Hoberg, Eric P.; Koehler, Anson V.; Henttonen, Heikki; Wickström, Lotta; Haukisalmi, Voitto; Galbreath, Kurt E.; Chernyavski, Felix; Dokuchaev, Nikolai; Lahzuhtkin, Anatoli; MacDonald, Stephen O.; Hope, Andrew G.; Waltari, Eric; Runck, Amy; Veitch, Alasdair; Jenkins, Emily; Kutz, Susan; Eckerlin, Ralph P.

    2005-01-01

    Beringia is the region spanning eastern Asia and northwestern North America that remained ice-free during the full glacial events of the Pleistocene. Numerous questions persist regarding the importance of this region in the evolution of northern faunas. Beringia has been implicated as both a high latitude refugium and as the crossroads (Bering Land Bridge) of the northern continents for boreal mammals. The Beringian Coevolution Project (BCP) is an international collaboration that has provided material to assess the pattern and timing of faunal exchange across the crossroads of the northern continents and the potential impact of past climatic events on differentiation. Mammals and associated parasite specimens have been collected and preserved from more than 200 field sites in eastern Russia, Alaska and northwestern Canada since 1999. Previously, fossils and taxonomic comparisons between Asia and North America mammals have shed light on these events. Molecular phylogenetics based on BCP specimens is now being used to trace the history of faunal exchange and diversification. We have found substantial phylogeographic structure in the Arctic and in Beringia in mustelid carnivores, arvicoline rodents, arctic hares and soricine shrews, including spatially concordant clades and contact zones across taxa that correspond to the edges of Beringia. Among the tapeworms of these mammalian hosts, new perspectives on diversity have also been developed. Arostrilepis horrida (Hymenolepididae) was considered to represent a single widespread and morphologically variable species occurring in a diversity of voles and lemmings in eastern and western Beringia and more broadly across the Holarctic region. The BCP has demonstrated a complex of at least 10 species that are poorly differentiated morphologically. The diversity of Paranoplocephala spp. and Anolocephaloides spp. (Anoplocephalidae) in Beringia included relatively few widespread and morphologically variable species in arvicolines

  15. SNV-PPILP: refined SNV calling for tumor data using perfect phylogenies and ILP.

    PubMed

    van Rens, Karen E; Mäkinen, Veli; Tomescu, Alexandru I

    2015-04-01

    Recent studies sequenced tumor samples from the same progenitor at different development stages and showed that by taking into account the phylogeny of this development, single-nucleotide variant (SNV) calling can be improved. Accurate SNV calls can better reveal early-stage tumors, identify mechanisms of cancer progression or help in drug targeting. We present SNV-PPILP, a fast and easy to use tool for refining GATK's Unified Genotyper SNV calls, for multiple samples assumed to form a phylogeny. We tested SNV-PPILP on simulated data, with a varying number of samples, SNVs, read coverage and violations of the perfect phylogeny assumption. We always match or improve the accuracy of GATK, with a significant improvement on low read coverage. SNV-PPILP, available at cs.helsinki.fi/gsa/snv-ppilp/, is written in Python and requires the free ILP solver lp_solve. Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. A synoptic review of Caryophyllaeus Gmelin, 1790 (Cestoda: Caryophyllidea), parasites of cyprinid fishes.

    PubMed

    Barcak, Daniel; Oros, Mikulas; Hanzelova, Vladimira; Scholz, Tomas

    2017-08-16

    Tapeworms of the genus Caryophyllaeus Gmelin, 1790 (Caryophyllidea: Caryophyllaeidae), common parasites of cyprinid fishes, are reviewed and taxonomic status of 42 nominal taxa that have been placed in the genus during its long history is clarified. The following seven species occurring in the Palaearctic Region are recognised as valid: C. laticeps (Pallas, 1781), C. auriculatus (Kulakovskaya, 1961), C. balticus (Szidat, 1941) comb. n. (syn. Khawia baltica Szidat, 1941), C. brachycollis Janiszewska, 1953, C. fimbriceps Annenkova-Chlopina, 1919, C. syrdarjensis Skrjabin, 1913, and newly described Caryophyllaeus chondrostomi sp. n. (= C. laticeps morphotype 4 of Bazsalovicsová et al., 2014) from common nase, Chondrostoma nasus (Linnaeus), found in Austria and Slovakia. The new species differs by the paramuscular or cortical position of preovarian vitelline follicles, a large, robust body (up to 64 mm long), conspicuously long vas deferens, flabellate scolex with small wrinkles on the anterior margin, and anteriormost testes located in a relatively short distance from the anterior extremity. Caryophyllaeus kashmirenses Mehra, 1930 and Caryophyllaeus prussicus (Szidat, 1937) comb. n. are considered to be species inquirendae, C. truncatus von Siebold in Baird, 1853 and C. tuba von Siebold in Baird, 1853 are nomina nuda. Data on the morphology, host spectra, distribution and known life-cycles of valid species are provided. Phylogenetic interrelations of four species of the genus including its type species and newly described C. chondrostomi were assessed based on an analysis of sequences of lsrDNA and cox1. A key to identification of all valid species of Caryophyllaeus is also provided.

  17. 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.

  18. Host phylogeny determines viral persistence and replication in novel hosts.

    PubMed

    Longdon, Ben; Hadfield, Jarrod D; Webster, Claire L; Obbard, Darren J; Jiggins, Francis M

    2011-09-01

    Pathogens switching to new hosts can result in the emergence of new infectious diseases, and determining which species are likely to be sources of such host shifts is essential to understanding disease threats to both humans and wildlife. However, the factors that determine whether a pathogen can infect a novel host are poorly understood. We have examined the ability of three host-specific RNA-viruses (Drosophila sigma viruses from the family Rhabdoviridae) to persist and replicate in 51 different species of Drosophilidae. Using a novel analytical approach we found that the host phylogeny could explain most of the variation in viral replication and persistence between different host species. This effect is partly driven by viruses reaching a higher titre in those novel hosts most closely related to the original host. However, there is also a strong effect of host phylogeny that is independent of the distance from the original host, with viral titres being similar in groups of related hosts. Most of this effect could be explained by variation in general susceptibility to all three sigma viruses, as there is a strong phylogenetic correlation in the titres of the three viruses. These results suggest that the source of new emerging diseases may often be predictable from the host phylogeny, but that the effect may be more complex than simply causing most host shifts to occur between closely related hosts.

  19. Host Phylogeny Determines Viral Persistence and Replication in Novel Hosts

    PubMed Central

    Longdon, Ben; Hadfield, Jarrod D.; Webster, Claire L.

    2011-01-01

    Pathogens switching to new hosts can result in the emergence of new infectious diseases, and determining which species are likely to be sources of such host shifts is essential to understanding disease threats to both humans and wildlife. However, the factors that determine whether a pathogen can infect a novel host are poorly understood. We have examined the ability of three host-specific RNA-viruses (Drosophila sigma viruses from the family Rhabdoviridae) to persist and replicate in 51 different species of Drosophilidae. Using a novel analytical approach we found that the host phylogeny could explain most of the variation in viral replication and persistence between different host species. This effect is partly driven by viruses reaching a higher titre in those novel hosts most closely related to the original host. However, there is also a strong effect of host phylogeny that is independent of the distance from the original host, with viral titres being similar in groups of related hosts. Most of this effect could be explained by variation in general susceptibility to all three sigma viruses, as there is a strong phylogenetic correlation in the titres of the three viruses. These results suggest that the source of new emerging diseases may often be predictable from the host phylogeny, but that the effect may be more complex than simply causing most host shifts to occur between closely related hosts. PMID:21966271

  20. Emergence of polycystic neotropical echinococcosis.

    PubMed

    Tappe, Dennis; Stich, August; Frosch, Matthias

    2008-02-01

    Echinococcosis is a parasitic zoonosis of increasing concern. In 1903, the first cases of human polycystic echinococcosis, a disease resembling alveolar echinococcosis, emerged in Argentina. One of the parasites responsible, Echinococcus oligarthrus, had been discovered in its adult strobilar stage before 1850. However, >100 years passed from the first description of the adult parasite to the recognition that this species is responsible for some cases of human neotropical polycystic echinococcosis and the elucidation of the parasite's life cycle. A second South American species, E. vogeli, was described in 1972. Obtaining recognition of the 2 species and establishing their connection to human disease were complicated because the life cycle of tapeworms is complex and comprises different developmental stages in diverse host species. To date, at least 106 human cases have been reported from 12 South and Central American countries.

  1. Lack of preference for infective faeces in Hymenolepis diminuta-infected beetles (Tenebrio molitor).

    PubMed

    Shea, John F

    2007-09-01

    The beetle-tapeworm life cycle provides a convenient system to study how host behaviour influences the probability of re-infection because initial and secondary infections can be tracked. The beetle, Tenebrio molitor, is infected with the tapeworm Hymenolepis diminuta when it ingests rat faeces containing tapeworm eggs, which upon hatching undergo five morphologically distinct stages while developing inside the beetle. In a series of preference trials, both individual and groups of previously infected beetles were exposed to baits of infective (faeces with eggs) and uninfective faeces. Beetles did not differ in the amount of time spent or in the number of occurrences at each bait type, suggesting that infected beetles show no preference for infective faeces. This may be a host adaptation to avoid further infection, parasite manipulation to avoid competition for host resources, or both. Further, once infected, beetles are no more or no less likely to become re-infected than uninfected beetles. An analysis of the mean and variance of infection suggests that some individuals are highly susceptible to and some are highly resistant to infection, with males being more variable than females. This could explain the higher load of cysticercoids observed in males.

  2. Characterisation and expression of a PP1 serine/threonine protein phosphatase (PfPP1) from the malaria parasite, Plasmodium falciparum: demonstration of its essential role using RNA interference

    PubMed Central

    Kumar, Rajinder; Adams, Brian; Oldenburg, Anja; Musiyenko, Alla; Barik, Sailen

    2002-01-01

    Background Reversible protein phosphorylation is relatively unexplored in the intracellular protozoa of the Apicomplexa family that includes the genus Plasmodium, to which belong the causative agents of malaria. Members of the PP1 family represent the most highly conserved protein phosphatase sequences in phylogeny and play essential regulatory roles in various cellular pathways. Previous evidence suggested a PP1-like activity in Plasmodium falciparum, not yet identified at the molecular level. Results We have identified a PP1 catalytic subunit from P. falciparum and named it PfPP1. The predicted primary structure of the 304-amino acid long protein was highly similar to PP1 sequences of other species, and showed conservation of all the signature motifs. The purified recombinant protein exhibited potent phosphatase activity in vitro. Its sensitivity to specific phosphatase inhibitors was characteristic of the PP1 class. The authenticity of the PfPP1 cDNA was further confirmed by mutational analysis of strategic amino acid residues important in catalysis. The protein was expressed in all erythrocytic stages of the parasite. Abrogation of PP1 expression by synthetic short interfering RNA (siRNA) led to inhibition of parasite DNA synthesis. Conclusions The high sequence similarity of PfPP1 with other PP1 members suggests conservation of function. Phenotypic gene knockdown studies using siRNA confirmed its essential role in the parasite. Detailed studies of PfPP1 and its regulation may unravel the role of reversible protein phosphorylation in the signalling pathways of the parasite, including glucose metabolism and parasitic cell division. The use of siRNA could be an important tool in the functional analysis of Apicomplexan genes. PMID:12057017

  3. AIDS-associated parasitic diarrhoea.

    PubMed

    Arora, D R; Arora, B

    2009-01-01

    Since the advent of human immunodeficiency virus infection, with its profound and progressive effect on the cellular immune system, a group of human opportunistic pathogens has come into prominence. Opportunistic parasitic infection can cause severe morbidity and mortality. Because many of these infections are treatable, an early and accurate diagnosis is important. This can be accomplished by a variety of methods such as direct demonstration of parasites and by serological tests to detect antigen and/or specific antibodies. However, antibody response may be poor in these patients and therefore immunodiagnostic tests have to be interpreted with caution. Cryptosporidium parvum, Isospora belli, Cyclospora cayetanensis, Microsporidia, Entamoeba histolytica and Strongyloides stercoralis are the commonly detected parasites. Detection of these parasites will help in proper management of these patients because drugs are available for most of these parasitic infections.

  4. Inferring epidemiological parameters from phylogenies using regression-ABC: A comparative study

    PubMed Central

    Gascuel, Olivier

    2017-01-01

    Inferring epidemiological parameters such as the R0 from time-scaled phylogenies is a timely challenge. Most current approaches rely on likelihood functions, which raise specific issues that range from computing these functions to finding their maxima numerically. Here, we present a new regression-based Approximate Bayesian Computation (ABC) approach, which we base on a large variety of summary statistics intended to capture the information contained in the phylogeny and its corresponding lineage-through-time plot. The regression step involves the Least Absolute Shrinkage and Selection Operator (LASSO) method, which is a robust machine learning technique. It allows us to readily deal with the large number of summary statistics, while avoiding resorting to Markov Chain Monte Carlo (MCMC) techniques. To compare our approach to existing ones, we simulated target trees under a variety of epidemiological models and settings, and inferred parameters of interest using the same priors. We found that, for large phylogenies, the accuracy of our regression-ABC is comparable to that of likelihood-based approaches involving birth-death processes implemented in BEAST2. Our approach even outperformed these when inferring the host population size with a Susceptible-Infected-Removed epidemiological model. It also clearly outperformed a recent kernel-ABC approach when assuming a Susceptible-Infected epidemiological model with two host types. Lastly, by re-analyzing data from the early stages of the recent Ebola epidemic in Sierra Leone, we showed that regression-ABC provides more realistic estimates for the duration parameters (latency and infectiousness) than the likelihood-based method. Overall, ABC based on a large variety of summary statistics and a regression method able to perform variable selection and avoid overfitting is a promising approach to analyze large phylogenies. PMID:28263987

  5. Pets and Parasites

    MedlinePlus

    ... in Children and TeensRead MoreBMI Calculator Cat and Dog BitesCat-Scratch DiseaseAvoiding SnakebitesDog Bites: How to Teach ... and Parasites Pets and Parasites Share Print A dog may be man’s best friend. However, household pets ...

  6. A new genus and species of proteocephalidean tapeworm (Cestoda), first parasite found in the driftwood catfish Tocantinsia piresi (Siluriformes: Auchenipteridae) from Brazil.

    PubMed

    Alves, Philippe Vieira; Chambrier, Alain de; Scholz, Tomas; Luque, Jose Luis

    2015-01-01

    Frezella gen. n. is proposed to accommodate Frezella vaucheri sp. n. from poorly known auchenipterid fish, Tocantinsia piresi (Miranda Ribeiro), from the Xingú River, one of the principal tributaries of the lower Amazon River in Brazil. The new genus belongs to the Proteocephalinae because of the medullary position of the testes, ovary (yet some follicles penetrate to the cortex on the dorsal side), vitelline follicles and uterus. It differs from other proteocephaline genera in the morphology of the scolex, which includes a metascolex composed of two distinct zones: anterior, strongly wrinkled part posterior to the suckers, and posterior, sparsely folded zone. Frezella can also be differentiated by having the internal longitudinal musculature hypertrophied laterally on both sides, the presence of some ovarian follicles in the cortex on the dorsal side and the presence of additional pair of tiny, thin-walled osmoregulatory canals situated slightly dorsomedian to ventral canals. Frezella vaucheri is the first helminth parasite reported from T. piresi, which occurs in the lower reaches of the Amazon and Tocantins River basins in Brazil.

  7. Genome Evolution of Plant-Parasitic Nematodes.

    PubMed

    Kikuchi, Taisei; Eves-van den Akker, Sebastian; Jones, John T

    2017-08-04

    Plant parasitism has evolved independently on at least four separate occasions in the phylum Nematoda. The application of next-generation sequencing (NGS) to plant-parasitic nematodes has allowed a wide range of genome- or transcriptome-level comparisons, and these have identified genome adaptations that enable parasitism of plants. Current genome data suggest that horizontal gene transfer, gene family expansions, evolution of new genes that mediate interactions with the host, and parasitism-specific gene regulation are important adaptations that allow nematodes to parasitize plants. Sequencing of a larger number of nematode genomes, including plant parasites that show different modes of parasitism or that have evolved in currently unsampled clades, and using free-living taxa as comparators would allow more detailed analysis and a better understanding of the organization of key genes within the genomes. This would facilitate a more complete understanding of the way in which parasitism has shaped the genomes of plant-parasitic nematodes.

  8. Trichinella spiralis: Adaptation and parasitism

    PubMed Central

    Zarlenga, Dante; Wang, Zhengyuan; Mitreva, Makedonka

    2016-01-01

    Publication of the genome from the clade I organism, Trichinella spiralis, has provided us an avenue to address more holistic problems in parasitology; namely the processes of adaptation and the evolution of parasitism. Parasitism among nematodes has evolved in multiple, independent events. Deciphering processes that drive species diversity and adaptation are keys to understanding parasitism and advancing control strategies. Studies have been put forth on morphological and physiological aspects of parasitism and adaptation in nematodes; however, data is now coming available to investigate adaptation, host switching and parasitism at the genomic level. Herein we compare proteomic data from the clade I parasite, Trichinella spiralis with data from Brugia malayi (clade III), Meloidogyne hapla and Meloidogyne incognita (clade IV), and free-living nematodes belonging to the genera Caenorhabditis and Pristionchus (clade V). We explore changes in protein family birth/death and expansion/reduction over the course of metazoan evolution using Homo sapiens, Drosophila melanogaster and Saccharomyces cerevisiae as out-groups for the phylum Nematoda. We further examine relationships between these changes and the ability and/or result of nematodes adapting to their environments. Data are consistent with gene loss occurring in conjunction with nematode specialization resulting from parasitic worms acclimating to well-defined, environmental niches. We observed evidence for independent, lateral gene transfer events involving conserved genes that may have played a role in the evolution of nematode parasitism. In general, parasitic nematodes gained proteins through duplication and lateral gene transfer, and lost proteins through random mutation and deletions. Data suggest independent acquisition rather than ancestral inheritance among the Nematoda followed by selective gene loss over evolutionary time. Data also show that parasitism and adaptation affected a broad range of proteins

  9. An experimental phylogeny to benchmark ancestral sequence reconstruction

    PubMed Central

    Randall, Ryan N.; Radford, Caelan E.; Roof, Kelsey A.; Natarajan, Divya K.; Gaucher, Eric A.

    2016-01-01

    Ancestral sequence reconstruction (ASR) is a still-burgeoning method that has revealed many key mechanisms of molecular evolution. One criticism of the approach is an inability to validate its algorithms within a biological context as opposed to a computer simulation. Here we build an experimental phylogeny using the gene of a single red fluorescent protein to address this criticism. The evolved phylogeny consists of 19 operational taxonomic units (leaves) and 17 ancestral bifurcations (nodes) that display a wide variety of fluorescent phenotypes. The 19 leaves then serve as ‘modern' sequences that we subject to ASR analyses using various algorithms and to benchmark against the known ancestral genotypes and ancestral phenotypes. We confirm computer simulations that show all algorithms infer ancient sequences with high accuracy, yet we also reveal wide variation in the phenotypes encoded by incorrectly inferred sequences. Specifically, Bayesian methods incorporating rate variation significantly outperform the maximum parsimony criterion in phenotypic accuracy. Subsampling of extant sequences had minor effect on the inference of ancestral sequences. PMID:27628687

  10. Parasites in bloom: flowers aid dispersal and transmission of pollinator parasites within and between bee species.

    PubMed

    Graystock, Peter; Goulson, Dave; Hughes, William O H

    2015-08-22

    The dispersal of parasites is critical for epidemiology, and the interspecific vectoring of parasites when species share resources may play an underappreciated role in parasite dispersal. One of the best examples of such a situation is the shared use of flowers by pollinators, but the importance of flowers and interspecific vectoring in the dispersal of pollinator parasites is poorly understood and frequently overlooked. Here, we use an experimental approach to show that during even short foraging periods of 3 h, three bumblebee parasites and two honeybee parasites were dispersed effectively onto flowers by their hosts, and then vectored readily between flowers by non-host pollinator species. The results suggest that flowers are likely to be hotspots for the transmission of pollinator parasites and that considering potential vector, as well as host, species will be of general importance for understanding the distribution and transmission of parasites in the environment and between pollinators. © 2015 The Author(s).

  11. Modelling the risk of Taenia solium exposure from pork produced in western Kenya.

    PubMed

    Thomas, Lian F; de Glanville, William A; Cook, Elizabeth A J; Bronsvoort, Barend M De C; Handel, Ian; Wamae, Claire N; Kariuki, Samuel; Fèvre, Eric M

    2017-02-01

    The tapeworm Taenia solium is the parasite responsible for neurocysticercosis, a neglected tropical disease of public health importance, thought to cause approximately 1/3 of epilepsy cases across endemic regions. The consumption of undercooked infected pork perpetuates the parasite's life-cycle through the establishment of adult tapeworm infections in the community. Reducing the risk associated with pork consumption in the developing world is therefore a public health priority. The aim of this study was to estimate the risk of any one pork meal in western Kenya containing a potentially infective T. solium cysticercus at the point of consumption, an aspect of the parasite transmission that has not been estimated before. To estimate this, we used a quantitative food chain risk assessment model built in the @RISK add-on to Microsoft Excel. This model indicates that any one pork meal consumed in western Kenya has a 0.006 (99% Uncertainty Interval (U.I). 0.0002-0.0164) probability of containing at least one viable T. solium cysticercus at the point of consumption and therefore being potentially infectious to humans. This equates to 22,282 (99% U.I. 622-64,134) potentially infective pork meals consumed in the course of one year within Busia District alone. This model indicates a high risk of T. solium infection associated with pork consumption in western Kenya and the work presented here can be built upon to investigate the efficacy of various mitigation strategies for this locality.

  12. Generalized Buneman Pruning for Inferring the Most Parsimonious Multi-state Phylogeny

    NASA Astrophysics Data System (ADS)

    Misra, Navodit; Blelloch, Guy; Ravi, R.; Schwartz, Russell

    Accurate reconstruction of phylogenies remains a key challenge in evolutionary biology. Most biologically plausible formulations of the problem are formally NP-hard, with no known efficient solution. The standard in practice are fast heuristic methods that are empirically known to work very well in general, but can yield results arbitrarily far from optimal. Practical exact methods, which yield exponential worst-case running times but generally much better times in practice, provide an important alternative. We report progress in this direction by introducing a provably optimal method for the weighted multi-state maximum parsimony phylogeny problem. The method is based on generalizing the notion of the Buneman graph, a construction key to efficient exact methods for binary sequences, so as to apply to sequences with arbitrary finite numbers of states with arbitrary state transition weights. We implement an integer linear programming (ILP) method for the multi-state problem using this generalized Buneman graph and demonstrate that the resulting method is able to solve data sets that are intractable by prior exact methods in run times comparable with popular heuristics. Our work provides the first method for provably optimal maximum parsimony phylogeny inference that is practical for multi-state data sets of more than a few characters.

  13. Synthesis of phylogeny and taxonomy into a comprehensive tree of life

    PubMed Central

    Hinchliff, Cody E.; Smith, Stephen A.; Allman, James F.; Burleigh, J. Gordon; Chaudhary, Ruchi; Coghill, Lyndon M.; Crandall, Keith A.; Deng, Jiabin; Drew, Bryan T.; Gazis, Romina; Gude, Karl; Hibbett, David S.; Katz, Laura A.; Laughinghouse, H. Dail; McTavish, Emily Jane; Midford, Peter E.; Owen, Christopher L.; Ree, Richard H.; Rees, Jonathan A.; Soltis, Douglas E.; Williams, Tiffani; Cranston, Karen A.

    2015-01-01

    Reconstructing the phylogenetic relationships that unite all lineages (the tree of life) is a grand challenge. The paucity of homologous character data across disparately related lineages currently renders direct phylogenetic inference untenable. To reconstruct a comprehensive tree of life, we therefore synthesized published phylogenies, together with taxonomic classifications for taxa never incorporated into a phylogeny. We present a draft tree containing 2.3 million tips—the Open Tree of Life. Realization of this tree required the assembly of two additional community resources: (i) a comprehensive global reference taxonomy and (ii) a database of published phylogenetic trees mapped to this taxonomy. Our open source framework facilitates community comment and contribution, enabling the tree to be continuously updated when new phylogenetic and taxonomic data become digitally available. Although data coverage and phylogenetic conflict across the Open Tree of Life illuminate gaps in both the underlying data available for phylogenetic reconstruction and the publication of trees as digital objects, the tree provides a compelling starting point for community contribution. This comprehensive tree will fuel fundamental research on the nature of biological diversity, ultimately providing up-to-date phylogenies for downstream applications in comparative biology, ecology, conservation biology, climate change, agriculture, and genomics. PMID:26385966

  14. Supermatrix phylogeny and biogeography of the Australasian Meliphagides radiation (Aves: Passeriformes).

    PubMed

    Marki, Petter Z; Jønsson, Knud A; Irestedt, Martin; Nguyen, Jacqueline M T; Rahbek, Carsten; Fjeldså, Jon

    2017-02-01

    With nearly 300 species, the infraorder Meliphagides represents one of the largest and most conspicuous Australasian bird radiations. Although the group has been the focus of a number of recent phylogenetic studies, a comprehensive species-level phylogenetic hypothesis is still lacking. This has impeded the assessment of broad-scale evolutionary, biogeographic and ecological hypotheses. In the present study, we use a supermatrix approach including five mitochondrial and four nuclear markers to infer a time-calibrated phylogeny of the Meliphagides. Our phylogeny, which includes 286 of the 289 (99%) currently recognized species, is largely congruent with previous estimates. However, the addition of 60 newly sequenced species reveals some novel relationships. Our biogeographic analyses suggest an Australian origin for the group in the early Oligocene (31.3Mya, 95% HPD 25.2-38.2Mya). In addition, we find that dispersal events out of Australia have been numerous and frequent, particularly to New Guinea, which has also been the source of multiple back-colonizations to the Australian mainland. The phylogeny provides an important framework for studying a wide variety of macroecological and macroevolutionary themes, including character evolution, origin and timing of diversification, biogeographic patterns and species responses to climate change. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. The crustacean parasites Ellobiopsis Caullery, 1910 and Thalassomyces Niezabitowski, 1913 form a monophyletic divergent clade within the Alveolata.

    PubMed

    Gómez, Fernando; López-García, Purificación; Nowaczyk, Antoine; Moreira, David

    2009-09-01

    The Ellobiopsidae are enigmatic parasites of crustaceans that have been grouped together exclusively on the basis of morphological similarities. Ultrastructural studies have revealed their affiliation within the alveolates, which was confirmed by the phylogenetic analysis of the ribosomal RNA gene (SSU rDNA) sequences of two species of Thalassomyces Niezabitowski, 1913. However, their precise systematic position within this group remains unresolved, since they could not be definitively allied with any particular alveolate group. To better determine the systematic position of ellobiopsids by molecular phylogeny, we sequenced the SSU rDNA from the type-species of the Ellobiopsidae, Ellobiopsis chattoni Caullery, 1910. We found E. chattoni infecting various copepod hosts, Acartia clausi Giesbrecht, Centropages typicus Kröyer and Clausocalanus sp., in the Bay of Marseille, NW Mediterranean Sea, which allowed us to study several stages of the parasite development. A single unicellular multinucleate specimen provided two different sequences of the SSU rDNA gene, indicating the existence of polymorphism at this locus within single individuals. Ellobiopsis Caullery, 1910 and Thalassomyces formed a very divergent and well-supported clade in phylogenetic analyses. This clade appears to be more closely related to the dinoflagellates (including the Syndiniales/Marine Alveolate Group II and the Dinokaryota) and Marine Alveolate Group I than to the other alveolates (Ciliophora, Perkinsozoa and Apicomplexa).

  16. Fossil Crustaceans as Parasites and Hosts.

    PubMed

    Klompmaker, Adiël A; Boxshall, Geoff A

    2015-01-01

    Numerous crustacean lineages have independently moved into parasitism as a mode of life. In modern marine ecosystems, parasitic crustaceans use representatives from many metazoan phyla as hosts. Crustaceans also serve as hosts to a rich diversity of parasites, including other crustaceans. Here, we show that the fossil record of such parasitic interactions is sparse, with only 11 examples, one dating back to the Cambrian. This may be due to the limited preservation potential and small size of parasites, as well as to problems with ascribing traces to parasitism with certainty, and to a lack of targeted research. Although the confirmed stratigraphic ranges are limited for nearly every example, evidence of parasitism related to crustaceans has become increasingly more complete for isopod-induced swellings in decapods so that quantitative analyses can be carried out. Little attention has yet been paid to the origin of parasitism in deep time, but insight can be generated by integrating data on fossils with molecular studies on modern parasites. In addition, there are other traces left by parasites that could fossilize, but have not yet been recognized in the fossil record. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Introduced species and their missing parasites

    USGS Publications Warehouse

    Torchin, Mark E.; Lafferty, Kevin D.; Dobson, Andrew P.; McKenzie, Valerie J.; Kuris, Armand M.

    2003-01-01

    Damage caused by introduced species results from the high population densities and large body sizes that they attain in their new location. Escape from the effects of natural enemies is a frequent explanation given for the success of introduced species. Because some parasites can reduce host density and decrease body size, an invader that leaves parasites behind and encounters few new parasites can experience a demographic release and become a pest. To test whether introduced species are less parasitized, we have compared the parasites of exotic species in their native and introduced ranges, using 26 host species of molluscs, crustaceans, fishes, birds, mammals, amphibians and reptiles. Here we report that the number of parasite species found in native populations is twice that found in exotic populations. In addition, introduced populations are less heavily parasitized (in terms of percentage infected) than are native populations. Reduced parasitization of introduced species has several causes, including reduced probability of the introduction of parasites with exotic species (or early extinction after host establishment), absence of other required hosts in the new location, and the host-specific limitations of native parasites adapting to new hosts.

  18. Fishing out marine parasites? Impacts of fishing on rates of parasitism in the ocean.

    PubMed

    Wood, Chelsea L; Lafferty, Kevin D; Micheli, Fiorenza

    2010-06-01

    Among anthropogenic effects on the ocean, fishing is one of the most pervasive and extends deepest into the past. Because fishing reduces the density of fish (reducing transmission efficiency of directly transmitted parasites), selectively removes large fish (which tend to carry more parasites than small fish), and reduces food web complexity (reducing transmission efficiency of trophically transmitted parasites), the removal of fish from the world's oceans over the course of hundreds of years may be driving a longterm, global decline in fish parasites. There has been growing recognition in recent years that parasites are a critical part of biodiversity and that their loss could substantially alter ecosystem function. Such a loss may be among the last major ecological effects of industrial fishing to be recognized by scientists.

  19. Evolutionary processes involved in the diversification of chelonian and mammal polystomatid parasites (Platyhelminthes, Monogenea, Polystomatidae) revealed by palaeoecology of their hosts.

    PubMed

    Héritier, Laurent; Badets, Mathieu; Du Preez, Louis H; Aisien, Martins S O; Lixian, Fan; Combes, Claude; Verneau, Olivier

    2015-11-01

    Polystomatid flatworms (Platyhelminthes) are monogenean parasites that infect exclusively aquatic or semi-aquatic sarcopterygians such as the Australian lungfish, amphibians, freshwater turtles and the African common hippopotamus. Previous studies on the phylogenetic relationships of these parasites, excluding Oculotrema hippopotami infecting common hippos, showed a global coevolution between hosts and their parasites at a macroevolutionary scale. These studies also demonstrated a strong correlation between the diversification of early neobatrachian polystomes and Gondwana breakup in the Mesozoic period. However the origin of chelonian polystomes is still in question as a switch from presumably primitive aquatic amniotes to turtles at the time of their first appearance, or soon after during their radiation, was assumed. In order to resolve this sticking point, we extended the phylogeny of polystomes with broader parasite sampling, i.e. 55 polystome species including Nanopolystoma tinsleyi a polystome infecting caecilians and O. hippopotami, and larger set of sequence data covering two nuclear and two mitochondrial genes coding for the ribosomal RNA 18S and 28S, the Cytochrome c Oxidase I and the ribosomal RNA 12S, respectively. The secondary structure of nuclear rRNAs genes (stems and loops) was taken into account for sequence alignments and Bayesian analyses were performed based on the appropriate models of evolution selected independently for the four designed partitions. Molecular calibrations were also conducted for dating the main speciation events in the polystome tree. The phylogenetic position of chelonian parasites that are phylogenetically closer to N. tinsleyi than all other amphibian polystomes and molecular time estimates suggest that these parasites originated following a switch from caecilians, at a geological period when primitive turtles may already have adapted to an aquatic life style, i.e. at about 178Million years ago, or a little later when

  20. Allee effect from parasite spill-back.

    PubMed

    Krkošek, Martin; Ashander, Jaime; Frazer, L Neil; Lewis, Mark A

    2013-11-01

    The exchange of native pathogens between wild and domesticated animals can lead to novel disease threats to wildlife. However, the dynamics of wild host-parasite systems exposed to a reservoir of domesticated hosts are not well understood. A simple mathematical model reveals that the spill-back of native parasites from domestic to wild hosts may cause a demographic Allee effect in the wild host population. A second model is tailored to the particulars of pink salmon (Oncorhynchus gorbuscha) and salmon lice (Lepeophtheirus salmonis), for which parasite spill-back is a conservation and fishery concern. In both models, parasite spill-back weakens the coupling of parasite and wild host abundance-particularly at low host abundance-causing parasites per host to increase as a wild host population declines. These findings show that parasites shared across host populations have effects analogous to those of generalist predators and can similarly cause an unstable equilibrium in a focal host population that separates persistence and extirpation. Allee effects in wildlife arising from parasite spill-back are likely to be most pronounced in systems where the magnitude of transmission from domestic to wild host populations is high because of high parasite abundance in domestic hosts, prolonged sympatry of domestic and wild hosts, a high transmission coefficient for parasites, long-lived parasite larvae, and proximity of domesticated populations to wildlife migration corridors.

  1. Manipulation of host behavior by parasitic insects and insect parasites.

    PubMed

    Libersat, Frederic; Delago, Antonia; Gal, Ram

    2009-01-01

    Parasites often alter the behavior of their hosts in ways that are ultimately beneficial to the parasite or its offspring. Although the alteration of host behavior by parasites is a widespread phenomenon, the underlying neuronal mechanisms are only beginning to be understood. Here, we focus on recent advances in the study of behavioral manipulation via modulation of the host central nervous system. We elaborate on a few case studies, in which recently published data provide explanations for the neuronal basis of parasite-induced alteration of host behavior. Among these, we describe how a worm may influence the nervous system of its cricket host and manipulate the cricket into committing suicide by jumping into water. We then focus on Ampulex compressa, which uses an Alien-like strategy for the sake of its offspring. Unlike most venomous hunters, this wasp injects venom directly into specific cerebral regions of its cockroach prey. As a result of the sting, the cockroach remains alive but immobile, but not paralyzed, and serves to nourish the developing wasp larva.

  2. A new theory of phylogeny inference through construction of multidimensional vector space.

    PubMed

    Kitazoe, Y; Kurihara, Y; Narita, Y; Okuhara, Y; Tominaga, A; Suzuki, T

    2001-05-01

    Here, a new theory of molecular phylogeny is developed in a multidimensional vector space (MVS). The molecular evolution is represented as a successive splitting of branch vectors in the MVS. The end points of these vectors are the extant species and indicate the specific directions reflected by their individual histories of evolution in the past. This representation makes it possible to infer the phylogeny (evolutionary histories) from the spatial positions of the end points. Search vectors are introduced to draw out the groups of species distributed around them. These groups are classified according to the nearby order of branches with them. A law of physics is applied to determine the species positions in the MVS. The species are regarded as the particles moving in time according to the equation of motion, finally falling into the lowest-energy state in spite of their randomly distributed initial condition. This falling into the ground state results in the construction of an MVS in which the relative distances between two particles are equal to the substitution distances. The species positions are obtained prior to the phylogeny inference. Therefore, as the number of species increases, the species vectors can be more specific in an MVS of a larger size, such that the vector analysis gives a more stable and reliable topology. The efficacy of the present method was examined by using computer simulations of molecular evolution in which all the branch- and end-point sequences of the trees are known in advance. In the phylogeny inference from the end points with 100 multiple data sets, the present method consistently reconstructed the correct topologies, in contrast to standard methods. In applications to 185 vertebrates in the alpha-hemoglobin, the vector analysis drew out the two lineage groups of birds and mammals. A core member of the mammalian radiation appeared at the base of the mammalian lineage. Squamates were isolated from the bird lineage to compose the

  3. Host-Parasite Interactions and Purifying Selection in a Microsporidian Parasite of Honey Bees

    PubMed Central

    Huang, Qiang; Chen, Yan Ping; Wang, Rui Wu; Cheng, Shang; Evans, Jay D.

    2016-01-01

    To clarify the mechanisms of Nosema ceranae parasitism, we deep-sequenced both honey bee host and parasite mRNAs throughout a complete 6-day infection cycle. By time-series analysis, 1122 parasite genes were significantly differently expressed during the reproduction cycle, clustering into 4 expression patterns. We found reactive mitochondrial oxygen species modulator 1 of the host to be significantly down regulated during the entire infection period. Our data support the hypothesis that apoptosis of honey bee cells was suppressed during infection. We further analyzed genome-wide genetic diversity of this parasite by comparing samples collected from the same site in 2007 and 2013. The number of SNP positions per gene and the proportion of non-synonymous substitutions per gene were significantly reduced over this time period, suggesting purifying selection on the parasite genome and supporting the hypothesis that a subset of N. ceranae strains might be dominating infection. PMID:26840596

  4. Host-Parasite Interactions and Purifying Selection in a Microsporidian Parasite of Honey Bees.

    PubMed

    Huang, Qiang; Chen, Yan Ping; Wang, Rui Wu; Cheng, Shang; Evans, Jay D

    2016-01-01

    To clarify the mechanisms of Nosema ceranae parasitism, we deep-sequenced both honey bee host and parasite mRNAs throughout a complete 6-day infection cycle. By time-series analysis, 1122 parasite genes were significantly differently expressed during the reproduction cycle, clustering into 4 expression patterns. We found reactive mitochondrial oxygen species modulator 1 of the host to be significantly down regulated during the entire infection period. Our data support the hypothesis that apoptosis of honey bee cells was suppressed during infection. We further analyzed genome-wide genetic diversity of this parasite by comparing samples collected from the same site in 2007 and 2013. The number of SNP positions per gene and the proportion of non-synonymous substitutions per gene were significantly reduced over this time period, suggesting purifying selection on the parasite genome and supporting the hypothesis that a subset of N. ceranae strains might be dominating infection.

  5. Parasite-induced aposematism” protects entomopathogenic nematode parasites against invertebrate enemies

    PubMed Central

    Fenton, Andy; Speed, Michael P.

    2016-01-01

    Aposematism is a well-known strategy in which prey defend themselves from predation by pairing defenses such as toxins, with warning signals that are often visually conspicuous color patterns. Here, we examine the possibility that aposematism can be induced in a host by colonies of infectious parasites in order to protect the parasites from the consequences of attacks on the host. Earlier studies show that avian predators are reluctant to feed on carcasses of host prey that are infected with the entomopathogenic nematode, Heterorhabditis bacteriophora. As the age of infection increases, the parasites kill and preserve the host and subsequently cause its color to change, becoming bright pink then red. Nematode colonies in dead hosts may also be vulnerable, however, to nocturnally active foragers that do not use vision in prey detection. Here, then we test a novel hypothesis that the nematode parasites also produce a warning odor, which functions to repel nocturnally active predators (in this case, the beetle Pterostichus madidus). We show that beetles decrease their feeding on infected insect prey as the age of infection increases and that olfactory cues associated with the infections are effective mechanisms for deterring beetle predation, even at very early stages of infection. We propose that “parasite-induced aposematism” from the nematodes serves to replace the antipredator defenses of the recently killed host. Because sessile carcasses are exposed to a greater range of predators than the live hosts, several alternative defense mechanisms are required to protect the colony, hence aposematic signals are likely diverse in such “parasite-induced aposematism.” PMID:27004015

  6. [Advances on antitumor effect of parasites].

    PubMed

    Wang, Su-wen; Sun, Jun

    2014-08-01

    Immune response induced by parasites could inhibit tumor growth and promote apoptosis of tumor cells. The investigation into this character will provide new insights on the anti-tumor effect of parasites. The mechanism of parasite immune evasion may provide a reference for tumor research. Furthermore, some anti-parasitic drugs have shown antitumor effect indicating that the development of antitumor drugs may get inspiration from anti-parasitic drug studies.

  7. Testing the new animal phylogeny: a phylum level molecular analysis of the animal kingdom.

    PubMed

    Bourlat, Sarah J; Nielsen, Claus; Economou, Andrew D; Telford, Maximilian J

    2008-10-01

    The new animal phylogeny inferred from ribosomal genes some years ago has prompted a number of radical rearrangements of the traditional, morphology based metazoan tree. The two main bilaterian clades, Deuterostomia and Protostomia, find strong support, but the protostomes consist of two sister groups, Ecdysozoa and Lophotrochozoa, not seen in morphology based trees. Although widely accepted, not all recent molecular phylogenetic analyses have supported the tripartite structure of the new animal phylogeny. Furthermore, even if the small ribosomal subunit (SSU) based phylogeny is correct, there is a frustrating lack of resolution of relationships between the phyla that make up the three clades of this tree. To address this issue, we have assembled a dataset including a large number of aligned sequence positions as well as a broad sampling of metazoan phyla. Our dataset consists of sequence data from ribosomal and mitochondrial genes combined with new data from protein coding genes (5139 amino acid and 3524 nucleotide positions in total) from 37 representative taxa sampled across the Metazoa. Our data show strong support for the basic structure of the new animal phylogeny as well as for the Mandibulata including Myriapoda. We also provide some resolution within the Lophotrochozoa, where we confirm support for a monophyletic clade of Echiura, Sipuncula and Annelida and surprising evidence of a close relationship between Brachiopoda and Nemertea.

  8. Parasites, Plants, and People.

    PubMed

    Johnson, Marion; Moore, Tony

    2016-06-01

    Anthelminthic resistance is acknowledged worldwide and is a major problem in Aotearoa New Zealand, thus alternative parasite management strategies are imperative. One Health is an initiative linking animal, human, and environmental health. Parasites, plants, and people illustrate the possibilities of providing diverse diets for stock thereby lowering parasite burdens, improving the cultural wellbeing of a local community, and protecting the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. 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

  10. Case report: the first case of human infection by adult of SPIROMETRA ERINACEIEUROPAEI in VIETNAM.

    PubMed

    Le, Anh Tran; Do, Le-Quyen Thi; Nguyen, Huong-Binh Thi; Nguyen, Hong-Ngoc Thi; Do, Anh Ngoc

    2017-10-10

    Tapeworms of the genus Spirometra include species whose larval stages can infect humans, causing a disease called sparganosis. Cases of human infection with adult worms are very rare and have been reported in Korea and China. Here we report the first case of human infection with an adult of Spirometra erinaceieuropaei in Vietnam. A 23-year-old male was admitted to 103 Military Hospital, Hanoi, Vietnam with fever, weight loss and epigastric discomfort. Preliminary diagnosis based on discovery of parasite eggs in his faeces incorrectly determined a fluke as the agent of the infection and praziquantel was prescribed. Two days later he passed out proglottids in his stool. The tapeworm was identified as Spirometra erinaceieuropaei using morphological and molecular tools. This is the first case of human infection with adult worm of Spirometra erinaceieuropaei in Vietnam.

  11. Mitogenomic perspectives on the origin and phylogeny of living amphibians.

    PubMed

    Zhang, Peng; Zhou, Hui; Chen, Yue-Qin; Liu, Yi-Fei; Qu, Liang-Hu

    2005-06-01

    Establishing the relationships among modern amphibians (lissamphibians) and their ancient relatives is necessary for our understanding of early tetrapod evolution. However, the phylogeny is still intractable because of the highly specialized anatomy and poor fossil record of lissamphibians. Paleobiologists are still not sure whether lissamphibians are monophyletic or polyphyletic, and which ancient group (temnospondyls or lepospondyls) is most closely related to them. In an attempt to address these problems, eight mitochondrial genomes of living amphibians were determined and compared with previously published amphibian sequences. A comprehensive molecular phylogenetic analysis of nucleotide sequences yields a highly resolved tree congruent with the traditional hypotheses (Batrachia). By using a molecular clock-independent approach for inferring dating information from molecular phylogenies, we present here the first molecular timescale for lissamphibian evolution, which suggests that lissamphibians first emerged about 330 million years ago. By observing the fit between molecular and fossil times, we suggest that the temnospondyl-origin hypothesis for lissamphibians is more credible than other hypotheses. Moreover, under this timescale, the potential geographic origins of the main living amphibian groups are discussed: (i) advanced frogs (neobatrachians) may possess an Africa-India origin; (ii) salamanders may have originated in east Asia; (iii) the tropic forest of the Triassic Pangaea may be the place of origin for the ancient caecilians. An accurate phylogeny with divergence times can be also helpful to direct the search for "missing" fossils, and can benefit comparative studies of amphibian evolution.

  12. Phylogeny and species traits predict bird detectability

    USGS Publications Warehouse

    Solymos, Peter; Matsuoka, Steven M.; Stralberg, Diana; Barker, Nicole K. S.; Bayne, Erin M.

    2018-01-01

    Avian acoustic communication has resulted from evolutionary pressures and ecological constraints. We therefore expect that auditory detectability in birds might be predictable by species traits and phylogenetic relatedness. We evaluated the relationship between phylogeny, species traits, and field‐based estimates of the two processes that determine species detectability (singing rate and detection distance) for 141 bird species breeding in boreal North America. We used phylogenetic mixed models and cross‐validation to compare the relative merits of using trait data only, phylogeny only, or the combination of both to predict detectability. We found a strong phylogenetic signal in both singing rates and detection distances; however the strength of phylogenetic effects was less than expected under Brownian motion evolution. The evolution of behavioural traits that determine singing rates was found to be more labile, leaving more room for species to evolve independently, whereas detection distance was mostly determined by anatomy (i.e. body size) and thus the laws of physics. Our findings can help in disentangling how complex ecological and evolutionary mechanisms have shaped different aspects of detectability in boreal birds. Such information can greatly inform single‐ and multi‐species models but more work is required to better understand how to best correct possible biases in phylogenetic diversity and other community metrics.

  13. The mitogenomic phylogeny of the Elasmobranchii (Chondrichthyes).

    PubMed

    Amaral, Cesar R L; Pereira, Filipe; Silva, Dayse A; Amorim, António; de Carvalho, Elizeu F

    2017-09-20

    Here we present a mitogenomic perspective on the evolution of sharks and rays, being a first glance on the complete mitochondrial history of such an old and diversified group of vertebrates. The Elasmobranchii is a diverse subclass of Chondrichthyes, or cartilaginous fish, with about 1200 species of ocean- and freshwater-dwelling fishes spread all over the world's seas, including some of the ocean's largest fishes. The group dates back about 400 million years near the Devonian-Silurian boundary, being nowadays represented by several derivative lineages, mainly related to Mesozoic forms. Although considered of ecological, commercial and conservation importance, the phylogeny of this old group is poorly studied and still under debate. Here we apply a molecular systematic approach on 82 complete mitochondrial genomes to investigate the phylogeny of the Elasmobranchii. By using maximum likelihood (ML) and Bayesian analyses, we found a clear separation within the shark clade between the Galeomorphii and the Squalomorphii, as well as sister taxa relationships between the Carcharhiniformes and the Lamniformes. Moreover, we found that Pristoidei clusters within the Rhinobatoidei, having been recovered as the sister taxon of the Rhinobatos genus in a clade which also includes the basal Zapteryx. Our results also reject the Hypnosqualea hypothesis, which proposes that the Batoidea should be placed within the Selachii.

  14. Parasite Prevalence Corresponds to Host Life History in a Diverse Assemblage of Afrotropical Birds and Haemosporidian Parasites

    PubMed Central

    Lutz, Holly L.; Hochachka, Wesley M.; Engel, Joshua I.; Bell, Jeffrey A.; Tkach, Vasyl V.; Bates, John M.; Hackett, Shannon J.; Weckstein, Jason D.

    2015-01-01

    Avian host life history traits have been hypothesized to predict rates of infection by haemosporidian parasites. Using molecular techniques, we tested this hypothesis for parasites from three haemosporidian genera (Plasmodium, Haemoproteus, and Leucocytozoon) collected from a diverse sampling of birds in northern Malawi. We found that host life history traits were significantly associated with parasitism rates by all three parasite genera. Nest type and nest location predicted infection probability for all three parasite genera, whereas flocking behavior is an important predictor of Plasmodium and Haemoproteus infection and habitat is an important predictor of Leucocytozoon infection. Parasite prevalence was 79.1% across all individuals sampled, higher than that reported for comparable studies from any other region of the world. Parasite diversity was also exceptionally high, with 248 parasite cytochrome b lineages identified from 152 host species. A large proportion of Plasmodium, Haemoproteus, and Leucocytozoon parasite DNA sequences identified in this study represent new, previously undocumented lineages (n = 201; 81% of total identified) based on BLAST queries against the avian malaria database, MalAvi. PMID:25853491

  15. Linking parasite populations in hosts to parasite populations in space through Taylor's law and the negative binomial distribution

    PubMed Central

    Poulin, Robert; Lagrue, Clément

    2017-01-01

    The spatial distribution of individuals of any species is a basic concern of ecology. The spatial distribution of parasites matters to control and conservation of parasites that affect human and nonhuman populations. This paper develops a quantitative theory to predict the spatial distribution of parasites based on the distribution of parasites in hosts and the spatial distribution of hosts. Four models are tested against observations of metazoan hosts and their parasites in littoral zones of four lakes in Otago, New Zealand. These models differ in two dichotomous assumptions, constituting a 2 × 2 theoretical design. One assumption specifies whether the variance function of the number of parasites per host individual is described by Taylor's law (TL) or the negative binomial distribution (NBD). The other assumption specifies whether the numbers of parasite individuals within each host in a square meter of habitat are independent or perfectly correlated among host individuals. We find empirically that the variance–mean relationship of the numbers of parasites per square meter is very well described by TL but is not well described by NBD. Two models that posit perfect correlation of the parasite loads of hosts in a square meter of habitat approximate observations much better than two models that posit independence of parasite loads of hosts in a square meter, regardless of whether the variance–mean relationship of parasites per host individual obeys TL or NBD. We infer that high local interhost correlations in parasite load strongly influence the spatial distribution of parasites. Local hotspots could influence control and conservation of parasites. PMID:27994156

  16. Parasite infracommunities of a specialized marine fish species in a compound community dominated by generalist parasites.

    PubMed

    Lanfranchi, A L; Rossin, M A; Timi, J T

    2009-12-01

    The structure and composition of parasite communities of Mullus argentinae were analysed under two alternative hypotheses in a sample of 75 specimens caught off Mar del Plata, Argentina (38 degrees 27'S, 57 degrees 90'W). The first, based on the dominance of trophically transmitted larval parasites of low host-specificity among fish species in the region, predicts that infracommunities will be random subsets of regionally available species. The second, based on previous studies on other mullids, predicts that infracommunities will be dominated by adult digeneans. The parasite fauna of goatfishes was mainly composed of endoparasites, with metacercariae of Prosorhynchus australis accounting for most individual parasites and greatly affecting infracommunity descriptors. Its importance was reinforced by the low number of trophically transmitted larval parasites. Both hypotheses were refuted; parasite communities were not dominated either by trophically transmitted larval parasites of low host-specificity or by adult digeneans. Prosorhynchus australis was the only species displaying any degree of phylogenetic specificity. Therefore, the influence of phylogenetic factors seems to exceed that of ecological ones in determining the observed structure of infracommunities. However, it is precisely host ecology that allows P. australis to become the determinant of infracommunity structure by constraining the acquisition of other parasites. Studies aiming to determine the relative importance of evolutionary and ecological processes as structuring forces of parasite communities should take into account not only the identity and specificity of their component parasites, but also their availability in the compound community.

  17. Fishing out marine parasites? Impacts of fishing on rates of parasitism in the ocean

    USGS Publications Warehouse

    Wood, Chelsea L.; Lafferty, Kevin D.; Micheli, Fiorenza

    2010-01-01

    Among anthropogenic effects on the ocean, fishing is one of the most pervasive and extends deepest into the past. Because fishing reduces the density of fish (reducing transmission efficiency of directly transmitted parasites), selectively removes large fish (which tend to carry more parasites than small fish), and reduces food web complexity (reducing transmission efficiency of trophically transmitted parasites), the removal of fish from the world’s oceans over the course of hundreds of years may be driving a long-term, global decline in fish parasites. There has been growing recognition in recent years that parasites are a critical part of biodiversity and that their loss could substantially alter ecosystem function. Such a loss may be among the last major ecological effects of industrial fishing to be recognized by scientists.

  18. Genome-Scale Phylogeny of the Alphavirus Genus Suggests a Marine Origin

    PubMed Central

    Palacios, G.; Tesh, R. B.; Savji, N.; Guzman, H.; Sherman, M.; Weaver, S. C.; Lipkin, W. I.

    2012-01-01

    The genus Alphavirus comprises a diverse group of viruses, including some that cause severe disease. Using full-length sequences of all known alphaviruses, we produced a robust and comprehensive phylogeny of the Alphavirus genus, presenting a more complete evolutionary history of these viruses compared to previous studies based on partial sequences. Our phylogeny suggests the origin of the alphaviruses occurred in the southern oceans and spread equally through the Old and New World. Since lice appear to be involved in aquatic alphavirus transmission, it is possible that we are missing a louse-borne branch of the alphaviruses. Complete genome sequencing of all members of the genus also revealed conserved residues forming the structural basis of the E1 and E2 protein dimers. PMID:22190718

  19. Parasitic miticidal therapy.

    PubMed

    Ghubash, Rudayna

    2006-08-01

    Parasites are a common cause of dermatological disease in the dog and cat. Knowledge of different miticidal options for the common parasitic diseases is imperative when choosing the appropriate treatment for a patient. This is especially important with the recent advent of safer and more effective antiparasitic medications. Diagnostic and therapeutic methods for Cheyletiella spp., Demodex spp., Notoedres cati, Sarcoptes scabei, and Otodectes cyanotis are discussed, with emphasis on protocols for miticidal therapies, as well as safety concerns and side effects. This information will allow the practitioner to choose the safest and most efficient treatment for parasitic skin disease in their small animal patients.

  20. PARASITES OF FISH

    EPA Science Inventory

    The intent of this chapter is to describe the parasites of importance to fishes maintained and used in laboratory settings. In contrast to the frist edition, the focus will be only on those parasites that pose a serious threat to or are common in fishes held in these confined en...

  1. Parasites in algae mass culture

    PubMed Central

    Carney, Laura T.; Lane, Todd W.

    2014-01-01

    Parasites are now known to be ubiquitous across biological systems and can play an important role in modulating algal populations. However, there is a lack of extensive information on their role in artificial ecosystems such as algal production ponds and photobioreactors. Parasites have been implicated in the demise of algal blooms. Because individual mass culture systems often tend to be unialgal and a select few algal species are in wide scale application, there is an increased potential for parasites to have a devastating effect on commercial scale monoculture. As commercial algal production continues to expand with a widening variety of applications, including biofuel, food and pharmaceuticals, the parasites associated with algae will become of greater interest and potential economic impact. A number of important algal parasites have been identified in algal mass culture systems in the last few years and this number is sure to grow as the number of commercial algae ventures increases. Here, we review the research that has identified and characterized parasites infecting mass cultivated algae, the techniques being proposed and or developed to control them, and the potential impact of parasites on the future of the algal biomass industry. PMID:24936200

  2. Evolutionary Origins of Rhizarian Parasites.

    PubMed

    Sierra, Roberto; Cañas-Duarte, Silvia J; Burki, Fabien; Schwelm, Arne; Fogelqvist, Johan; Dixelius, Christina; González-García, Laura N; Gile, Gillian H; Slamovits, Claudio H; Klopp, Christophe; Restrepo, Silvia; Arzul, Isabelle; Pawlowski, Jan

    2016-04-01

    The SAR group (Stramenopila, Alveolata, Rhizaria) is one of the largest clades in the tree of eukaryotes and includes a great number of parasitic lineages. Rhizarian parasites are obligate and have devastating effects on commercially important plants and animals but despite this fact, our knowledge of their biology and evolution is limited. Here, we present rhizarian transcriptomes from all major parasitic lineages in order to elucidate their evolutionary relationships using a phylogenomic approach. Our results suggest that Ascetosporea, parasites of marine invertebrates, are sister to the novel clade Apofilosa. The phytomyxean plant parasites branch sister to the vampyrellid algal ectoparasites in the novel clade Phytorhiza. They also show that Ascetosporea + Apofilosa + Retaria + Filosa + Phytorhiza form a monophyletic clade, although the branching pattern within this clade is difficult to resolve and appears to be model-dependent. Our study does not support the monophyly of the rhizarian parasitic lineages (Endomyxa), suggesting independent origins for rhizarian animal and plant parasites. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Cardiac Involvement with Parasitic Infections

    PubMed Central

    Hidron, Alicia; Vogenthaler, Nicholas; Santos-Preciado, José I.; Rodriguez-Morales, Alfonso J.; Franco-Paredes, Carlos; Rassi, Anis

    2010-01-01

    Summary: Parasitic infections previously seen only in developing tropical settings can be currently diagnosed worldwide due to travel and population migration. Some parasites may directly or indirectly affect various anatomical structures of the heart, with infections manifested as myocarditis, pericarditis, pancarditis, or pulmonary hypertension. Thus, it has become quite relevant for clinicians in developed settings to consider parasitic infections in the differential diagnosis of myocardial and pericardial disease anywhere around the globe. Chagas' disease is by far the most important parasitic infection of the heart and one that it is currently considered a global parasitic infection due to the growing migration of populations from areas where these infections are highly endemic to settings where they are not endemic. Current advances in the treatment of African trypanosomiasis offer hope to prevent not only the neurological complications but also the frequently identified cardiac manifestations of this life-threatening parasitic infection. The lack of effective vaccines, optimal chemoprophylaxis, or evidence-based pharmacological therapies to control many of the parasitic diseases of the heart, in particular Chagas' disease, makes this disease one of the most important public health challenges of our time. PMID:20375355

  4. Parasites and immunotherapy: with or against?

    PubMed

    Yousofi Darani, Hossein; Yousefi, Morteza; Safari, Marzieh; Jafari, Rasool

    2016-06-01

    Immunotherapy is a sort of therapy in which antibody or antigen administrates to the patient in order to treat or reduce the severity of complications of disease. This kind of treatment practiced in a wide variety of diseases including infectious diseases, autoimmune disorders, cancers and allergy. Successful and unsuccessful immunotherapeutic strategies have been practiced in variety of parasitic infections. On the other hand parasites or parasite antigens have also been considered for immunotherapy against other diseases such as cancer, asthma and multiple sclerosis. In this paper immunotherapy against common parasitic infections, and also immunotherapy of cancer, asthma and multiple sclerosis with parasites or parasite antigens have been reviewed.

  5. Parasitic worms: how many really?

    PubMed

    Strona, Giovanni; Fattorini, Simone

    2014-04-01

    Accumulation curves are useful tools to estimate species diversity. Here we argue that they can also be used in the study of global parasite species richness. Although this basic idea is not completely new, our approach differs from the previous ones as it treats each host species as an independent sample. We show that randomly resampling host-parasite records from the existing databases makes it possible to empirically model the relationship between the number of investigated host species, and the corresponding number of parasite species retrieved from those hosts. This method was tested on 21 inclusive lists of parasitic worms occurring on vertebrate hosts. All of the obtained models conform well to a power law curve. These curves were then used to estimate global parasite species richness. Results obtained with the new method suggest that current predictions are likely to severely overestimate parasite diversity. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  6. A malaria parasite formin regulates actin polymerization and localizes to the parasite-erythrocyte moving junction during invasion.

    PubMed

    Baum, Jake; Tonkin, Christopher J; Paul, Aditya S; Rug, Melanie; Smith, Brian J; Gould, Sven B; Richard, Dave; Pollard, Thomas D; Cowman, Alan F

    2008-03-13

    Malaria parasites invade host cells using actin-based motility, a process requiring parasite actin filament nucleation and polymerization. Malaria and other apicomplexan parasites lack Arp2/3 complex, an actin nucleator widely conserved across eukaryotes, but do express formins, another type of actin nucleator. Here, we demonstrate that one of two malaria parasite formins, Plasmodium falciparum formin 1 (PfFormin 1), and its ortholog in the related parasite Toxoplasma gondii, follows the moving tight junction between the invading parasite and the host cell, which is the predicted site of the actomyosin motor that powers motility. Furthermore, in vitro, the PfFormin1 actin-binding formin homology 2 domain is a potent nucleator, stimulating actin polymerization and, like other formins, localizing to the barbed end during filament elongation. These findings support a conserved molecular mechanism underlying apicomplexan parasite motility and, given the essential role that actin plays in cell invasion, highlight formins as important determinants of malaria parasite pathogenicity.

  7. `Inter-Arrival Time' Inspired Algorithm and its Application in Clustering and Molecular Phylogeny

    NASA Astrophysics Data System (ADS)

    Kolekar, Pandurang S.; Kale, Mohan M.; Kulkarni-Kale, Urmila

    2010-10-01

    Bioinformatics, being multidisciplinary field, involves applications of various methods from allied areas of Science for data mining using computational approaches. Clustering and molecular phylogeny is one of the key areas in Bioinformatics, which help in study of classification and evolution of organisms. Molecular phylogeny algorithms can be divided into distance based and character based methods. But most of these methods are dependent on pre-alignment of sequences and become computationally intensive with increase in size of data and hence demand alternative efficient approaches. `Inter arrival time distribution' (IATD) is a popular concept in the theory of stochastic system modeling but its potential in molecular data analysis has not been fully explored. The present study reports application of IATD in Bioinformatics for clustering and molecular phylogeny. The proposed method provides IATDs of nucleotides in genomic sequences. The distance function based on statistical parameters of IATDs is proposed and distance matrix thus obtained is used for the purpose of clustering and molecular phylogeny. The method is applied on a dataset of 3' non-coding region sequences (NCR) of Dengue virus type 3 (DENV-3), subtype III, reported in 2008. The phylogram thus obtained revealed the geographical distribution of DENV-3 isolates. Sri Lankan DENV-3 isolates were further observed to be clustered in two sub-clades corresponding to pre and post Dengue hemorrhagic fever emergence groups. These results are consistent with those reported earlier, which are obtained using pre-aligned sequence data as an input. These findings encourage applications of the IATD based method in molecular phylogenetic analysis in particular and data mining in general.

  8. Relationships of Reproductive Traits With the Phylogeny of the African Noctuid Stem Borers

    PubMed Central

    Calatayud, Paul-André; Dupas, Stéphane; Frérot, Brigitte; Genestier, Gilles; Ahuya, Peter; Capdevielle-Dulac, Claire; Le Ru, Bruno

    2016-01-01

    The display of the reproductive behavior in most noctuid Lepidoptera follows a diel periodicity and is limited to a precise period of either the day or the night. These behavioral traits and the sex pheromone chemistry can be species specific and thus might be linked to the phylogeny. The objective of this study was to test the relationship of these reproductive traits with phylogeny. The study was undertaken using eight closely related species of noctuid stem borers, which are easy to rear under artificial conditions, namely, Busseola fusca, B. nairobica, B. sp. nr. segeta, Manga melanodonta, M. sp. nr. nubifera, Pirateolea piscator, Sesamia calamistis, and S. nonagrioides. For each species, the adult emergence period, the mating time, and the oviposition period were estimated, referred as biological traits. The components of the sex pheromones emitted by the females of each species were also analyzed by gas chromatography–mass spectrometry. Among the biological traits measured, only those linked to the oviposition pattern (timing and egg loads per night) were significantly correlated with the phylogeny of these species. For the sex pheromone components, among the 13 components identified in all species, only four, namely, Z9-tetradecenyl acetate (Z9-TDA), Z11-TDA, E11-TDA, and Z11-hexadecenyl acetate (Z11-HDA), showed the highest significant correlations with the phylogeny. These results suggest that among the different reproductive traits evaluated, only few are phylogenetically constrained. Their involvement in the reinforcement of ecological speciation in noctuid stem borers is discussed. PMID:27867304

  9. A core phylogeny of Dictyostelia inferred from genomes representative of the eight major and minor taxonomic divisions of the group.

    PubMed

    Singh, Reema; Schilde, Christina; Schaap, Pauline

    2016-11-17

    Dictyostelia are a well-studied group of organisms with colonial multicellularity, which are members of the mostly unicellular Amoebozoa. A phylogeny based on SSU rDNA data subdivided all Dictyostelia into four major groups, but left the position of the root and of six group-intermediate taxa unresolved. Recent phylogenies inferred from 30 or 213 proteins from sequenced genomes, positioned the root between two branches, each containing two major groups, but lacked data to position the group-intermediate taxa. Since the positions of these early diverging taxa are crucial for understanding the evolution of phenotypic complexity in Dictyostelia, we sequenced six representative genomes of early diverging taxa. We retrieved orthologs of 47 housekeeping proteins with an average size of 890 amino acids from six newly sequenced and eight published genomes of Dictyostelia and unicellular Amoebozoa and inferred phylogenies from single and concatenated protein sequence alignments. Concatenated alignments of all 47 proteins, and four out of five subsets of nine concatenated proteins all produced the same consensus phylogeny with 100% statistical support. Trees inferred from just two out of the 47 proteins, individually reproduced the consensus phylogeny, highlighting that single gene phylogenies will rarely reflect correct species relationships. However, sets of two or three concatenated proteins again reproduced the consensus phylogeny, indicating that a small selection of genes suffices for low cost classification of as yet unincorporated or newly discovered dictyostelid and amoebozoan taxa by gene amplification. The multi-locus consensus phylogeny shows that groups 1 and 2 are sister clades in branch I, with the group-intermediate taxon D. polycarpum positioned as outgroup to group 2. Branch II consists of groups 3 and 4, with the group-intermediate taxon Polysphondylium violaceum positioned as sister to group 4, and the group-intermediate taxon Dictyostelium polycephalum

  10. A Lack of Parasitic Reduction in the Obligate Parasitic Green Alga Helicosporidium

    PubMed Central

    Pombert, Jean-François; Blouin, Nicolas Achille; Lane, Chris; Boucias, Drion; Keeling, Patrick J.

    2014-01-01

    The evolution of an obligate parasitic lifestyle is often associated with genomic reduction, in particular with the loss of functions associated with increasing host-dependence. This is evident in many parasites, but perhaps the most extreme transitions are from free-living autotrophic algae to obligate parasites. The best-known examples of this are the apicomplexans such as Plasmodium, which evolved from algae with red secondary plastids. However, an analogous transition also took place independently in the Helicosporidia, where an obligate parasite of animals with an intracellular infection mechanism evolved from algae with green primary plastids. We characterised the nuclear genome of Helicosporidium to compare its transition to parasitism with that of apicomplexans. The Helicosporidium genome is small and compact, even by comparison with the relatively small genomes of the closely related green algae Chlorella and Coccomyxa, but at the functional level we find almost no evidence for reduction. Nearly all ancestral metabolic functions are retained, with the single major exception of photosynthesis, and even here reduction is not complete. The great majority of genes for light-harvesting complexes, photosystems, and pigment biosynthesis have been lost, but those for other photosynthesis-related functions, such as Calvin cycle, are retained. Rather than loss of whole function categories, the predominant reductive force in the Helicosporidium genome is a contraction of gene family complexity, but even here most losses affect families associated with genome maintenance and expression, not functions associated with host-dependence. Other gene families appear to have expanded in response to parasitism, in particular chitinases, including those predicted to digest the chitinous barriers of the insect host or remodel the cell wall of Helicosporidium. Overall, the Helicosporidium genome presents a fascinating picture of the early stages of a transition from free

  11. Ontogeny and Phylogeny from an Epigenetic Point of View.

    ERIC Educational Resources Information Center

    Lovtrup, Soren

    1984-01-01

    The correlation between ontogeny and phylogeny is analyzed through the discussion of four theories on the reality, history, epigenetic, and ecological aspects of the mechanism of evolution. Also discussed are historical and creative aspects of evolution and three epigenetic mechanisms instantiated in the case of the amphibian embryo. (Author/RH)

  12. The Effect and Relative Importance of Neutral Genetic Diversity for Predicting Parasitism Varies across Parasite Taxa

    PubMed Central

    Ruiz-López, María José; Monello, Ryan J.; Gompper, Matthew E.; Eggert, Lori S.

    2012-01-01

    Understanding factors that determine heterogeneity in levels of parasitism across individuals is a major challenge in disease ecology. It is known that genetic makeup plays an important role in infection likelihood, but the mechanism remains unclear as does its relative importance when compared to other factors. We analyzed relationships between genetic diversity and macroparasites in outbred, free-ranging populations of raccoons (Procyon lotor). We measured heterozygosity at 14 microsatellite loci and modeled the effects of both multi-locus and single-locus heterozygosity on parasitism using an information theoretic approach and including non-genetic factors that are known to influence the likelihood of parasitism. The association of genetic diversity and parasitism, as well as the relative importance of genetic diversity, differed by parasitic group. Endoparasite species richness was better predicted by a model that included genetic diversity, with the more heterozygous hosts harboring fewer endoparasite species. Genetic diversity was also important in predicting abundance of replete ticks (Dermacentor variabilis). This association fit a curvilinear trend, with hosts that had either high or low levels of heterozygosity harboring fewer parasites than those with intermediate levels. In contrast, genetic diversity was not important in predicting abundance of non-replete ticks and lice (Trichodectes octomaculatus). No strong single-locus effects were observed for either endoparasites or replete ticks. Our results suggest that in outbred populations multi-locus diversity might be important for coping with parasitism. The differences in the relationships between heterozygosity and parasitism for the different parasites suggest that the role of genetic diversity varies with parasite-mediated selective pressures. PMID:23049796

  13. Parasite specialization in a unique habitat: hummingbirds as reservoirs of generalist blood parasites of Andean birds.

    PubMed

    Moens, Michaël A J; Valkiūnas, Gediminas; Paca, Anahi; Bonaccorso, Elisa; Aguirre, Nikolay; Pérez-Tris, Javier

    2016-09-01

    Understanding how parasites fill their ecological niches requires information on the processes involved in the colonization and exploitation of unique host species. Switching to hosts with atypical attributes may favour generalists broadening their niches or may promote specialization and parasite diversification as the consequence. We analysed which blood parasites have successfully colonized hummingbirds, and how they have evolved to exploit such a unique habitat. We specifically asked (i) whether the assemblage of Haemoproteus parasites of hummingbirds is the result of single or multiple colonization events, (ii) to what extent these parasites are specialized in hummingbirds or shared with other birds and (iii) how hummingbirds contribute to sustain the populations of these parasites, in terms of both prevalence and infection intensity. We sampled 169 hummingbirds of 19 species along an elevation gradient in Southern Ecuador to analyse the host specificity, diversity and infection intensity of Haemoproteus by molecular and microscopy techniques. In addition, 736 birds of 112 species were analysed to explore whether hummingbird parasites are shared with other birds. Hummingbirds hosted a phylogenetically diverse assemblage of generalist Haemoproteus lineages shared with other host orders. Among these parasites, Haemoproteus witti stood out as the most generalized. Interestingly, we found that infection intensities of this parasite were extremely low in passerines (with no detectable gametocytes), but very high in hummingbirds, with many gametocytes seen. Moreover, infection intensities of H. witti were positively correlated with the prevalence across host species. Our results show that hummingbirds have been colonized by generalist Haemoproteus lineages on multiple occasions. However, one of these generalist parasites (H. witti) seems to be highly dependent on hummingbirds, which arise as the most relevant reservoirs in terms of both prevalence and

  14. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites, or...

  15. Parasitism and the Biodiversity-Functioning Relationship.

    PubMed

    Frainer, André; McKie, Brendan G; Amundsen, Per-Arne; Knudsen, Rune; Lafferty, Kevin D

    2018-04-01

    Species interactions can influence ecosystem functioning by enhancing or suppressing the activities of species that drive ecosystem processes, or by causing changes in biodiversity. However, one important class of species interactions - parasitism - has been little considered in biodiversity and ecosystem functioning (BD-EF) research. Parasites might increase or decrease ecosystem processes by reducing host abundance. Parasites could also increase trait diversity by suppressing dominant species or by increasing within-host trait diversity. These different mechanisms by which parasites might affect ecosystem function pose challenges in predicting their net effects. Nonetheless, given the ubiquity of parasites, we propose that parasite-host interactions should be incorporated into the BD-EF framework. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Nuclear hormone receptors in parasitic helminths

    PubMed Central

    Wu, Wenjie; LoVerde, Philip T

    2010-01-01

    Nuclear receptors (NRs) belong to a large protein superfamily that are important transcriptional modulators in metazoans. Parasitic helminths include parasitic worms from the Lophotrochozoa (Platyhelminths) and Ecdysozoa (Nematoda). NRs in parasitic helminths diverged into two different evolutionary lineages. NRs in parasitic Platyhelminths have orthologues in Deuterostomes, in arthropods or both with a feature of extensive gene loss and gene duplication within different gene groups. NRs in parasitic Nematoda follow the nematode evolutionary lineage with a feature of multiple duplication of SupNRs and gene loss. PMID:20600585

  17. A review of taeniasis and cysticercosis in the Lao People's Democratic Republic.

    PubMed

    Conlan, James; Khounsy, Syseng; Inthavong, Phouth; Fenwick, Stanley; Blacksell, Stuart; Thompson, R C Andrew

    2008-09-01

    Taeniasis and cysticercosis are important but underreported parasitic zoonoses in the Lao People's Democratic Republic (Lao PDR). Reports of human and pig cysticercosis are rather limited and based largely on anecdotal evidence. To date, no structured surveys of disease prevalence or incidence have been reported. However, one unpublished pilot survey of pig cysticercosis in a slaughterhouse in northern Laos estimated prevalence to be 1.7%, without speciation of parasite cysts. Over the past 20 years, nine surveys of intestinal helminthic infection have been conducted; the prevalence of human taeniasis ranged from 0 to 14.0%. The study designs and sample sizes varied greatly, however a high degree of spatial and age variation in taeniasis prevalence was evident. These results are however inconclusive as the species of tapeworm infecting the people was not determined. To further our knowledge of taeniasis and cysticercosis in Lao PDR, structured community-based surveys in high-risk areas are required in combination with the use of sensitive and specific diagnostic tests capable of identifying the pork tapeworm, Taenia solium. This will enable the development and implementation of control measures that are both appropriate and sustainable if T. solium is shown to be a public health threat.

  18. Molecular phylogeny of Entomophthoromycota

    USDA-ARS?s Scientific Manuscript database

    The Entomophthoromycota is a ubiquitous group of fungi best known as pathogens of a wide variety of economically important insect pests, arachnids, and other soil invertebrates, a smaller number of parasites of reptiles, vertebrates (including humans), macromycetes, fern gametophytes, and desmid alg...

  19. Host Sexual Dimorphism and Parasite Adaptation

    PubMed Central

    Duneau, David; Ebert, Dieter

    2012-01-01

    In species with separate sexes, parasite prevalence and disease expression is often different between males and females. This effect has mainly been attributed to sex differences in host traits, such as immune response. Here, we make the case for how properties of the parasites themselves can also matter. Specifically, we suggest that differences between host sexes in many different traits, such as morphology and hormone levels, can impose selection on parasites. This selection can eventually lead to parasite adaptations specific to the host sex more commonly encountered, or to differential expression of parasite traits depending on which host sex they find themselves in. Parasites adapted to the sex of the host in this way can contribute to differences between males and females in disease prevalence and expression. Considering those possibilities can help shed light on host–parasite interactions, and impact epidemiological and medical science. PMID:22389630

  20. The role of moulting in parasite defence

    PubMed Central

    Duneau, David; Ebert, Dieter

    2012-01-01

    Parasitic infections consist of a succession of steps during which hosts and parasites interact in specific manners. At each step, hosts can use diverse defence mechanisms to counteract the parasite's attempts to invade and exploit them. Of these steps, the penetration of parasites into the host is a key step for a successful infection and the epithelium is the first line of host defence. The shedding of this protective layer (moulting) is a crucial feature in the life cycle of several invertebrate and vertebrate taxa, and is generally considered to make hosts vulnerable to parasites and predators. Here, we used the crustacean Daphnia magna to test whether moulting influences the likelihood of infection by the castrating bacterium Pasteuria ramosa. This parasite is known to attach to the host cuticula before penetrating into its body. We found that the likelihood of successful parasite infection is greatly reduced if the host moults within 12 h after parasite exposure. Thus, moulting is beneficial for the host being exposed to this parasite. We further show that exposure to the parasite does not induce hosts to moult earlier. We discuss the implications of our findings for host and parasite evolution and epidemiology. PMID:22496187