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Sample records for nematode parasitic adaptation

  1. Signatures of adaptation to plant parasitism in nematode genomes.

    Science.gov (United States)

    Bird, David McK; Jones, John T; Opperman, Charles H; Kikuchi, Taisei; Danchin, Etienne G J

    2015-02-01

    Plant-parasitic nematodes cause considerable damage to global agriculture. The ability to parasitize plants is a derived character that appears to have independently emerged several times in the phylum Nematoda. Morphological convergence to feeding style has been observed, but whether this is emergent from molecular convergence is less obvious. To address this, we assess whether genomic signatures can be associated with plant parasitism by nematodes. In this review, we report genomic features and characteristics that appear to be common in plant-parasitic nematodes while absent or rare in animal parasites, predators or free-living species. Candidate horizontal acquisitions of parasitism genes have systematically been found in all plant-parasitic species investigated at the sequence level. Presence of peptides that mimic plant hormones also appears to be a trait of plant-parasitic species. Annotations of the few genomes of plant-parasitic nematodes available to date have revealed a set of apparently species-specific genes on every occasion. Effector genes, important for parasitism are frequently found among those species-specific genes, indicating poor overlap. Overall, nematodes appear to have developed convergent genomic solutions to adapt to plant parasitism.

  2. Genomic mechanisms accounting for the adaptation to parasitism in nematode-trapping fungi.

    Directory of Open Access Journals (Sweden)

    Tejashwari Meerupati

    2013-11-01

    Full Text Available Orbiliomycetes is one of the earliest diverging branches of the filamentous ascomycetes. The class contains nematode-trapping fungi that form unique infection structures, called traps, to capture and kill free-living nematodes. The traps have evolved differently along several lineages and include adhesive traps (knobs, nets or branches and constricting rings. We show, by genome sequencing of the knob-forming species Monacrosporium haptotylum and comparison with the net-forming species Arthrobotrys oligospora, that two genomic mechanisms are likely to have been important for the adaptation to parasitism in these fungi. Firstly, the expansion of protein domain families and the large number of species-specific genes indicated that gene duplication followed by functional diversification had a major role in the evolution of the nematode-trapping fungi. Gene expression indicated that many of these genes are important for pathogenicity. Secondly, gene expression of orthologs between the two fungi during infection indicated that differential regulation was an important mechanism for the evolution of parasitism in nematode-trapping fungi. Many of the highly expressed and highly upregulated M. haptotylum transcripts during the early stages of nematode infection were species-specific and encoded small secreted proteins (SSPs that were affected by repeat-induced point mutations (RIP. An active RIP mechanism was revealed by lack of repeats, dinucleotide bias in repeats and genes, low proportion of recent gene duplicates, and reduction of recent gene family expansions. The high expression and rapid divergence of SSPs indicate a striking similarity in the infection mechanisms of nematode-trapping fungi and plant and insect pathogens from the crown groups of the filamentous ascomycetes (Pezizomycotina. The patterns of gene family expansions in the nematode-trapping fungi were more similar to plant pathogens than to insect and animal pathogens. The observation

  3. Genome Evolution of Plant-Parasitic Nematodes.

    Science.gov (United States)

    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.

  4. Parallel adaptations and common host cell responses enabling feeding of obligate and facultative plant parasitic nematodes

    NARCIS (Netherlands)

    Smant, Geert; Helder, Johannes; Goverse, Aska

    2018-01-01

    Parallel adaptations enabling the use of plant cells as the primary food source have occurred multiple times in distinct nematode clades. The hallmark of all extant obligate and facultative plant-feeding nematodes is the presence of an oral stylet, which is required for penetration of plant cell

  5. RNA interference in plant parasitic nematodes

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-04

    Aug 4, 2008 ... nematodes. RNAi should help identify gene and, hence, protein targets for nematode control strategies. Key words: RNA interference, RNAi, gene expression, plant parasitic nematodes. INTRODUCTION. Plant parasitic nematodes are found as pests of crops throughout the world with many having a severe ...

  6. Adaptive radiation within marine anisakid nematodes: a zoogeographical modeling of cosmopolitan, zoonotic parasites.

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    Thomas Kuhn

    Full Text Available Parasites of the nematode genus Anisakis are associated with aquatic organisms. They can be found in a variety of marine hosts including whales, crustaceans, fish and cephalopods and are known to be the cause of the zoonotic disease anisakiasis, a painful inflammation of the gastro-intestinal tract caused by the accidental consumptions of infectious larvae raw or semi-raw fishery products. Since the demand on fish as dietary protein source and the export rates of seafood products in general is rapidly increasing worldwide, the knowledge about the distribution of potential foodborne human pathogens in seafood is of major significance for human health. Studies have provided evidence that a few Anisakis species can cause clinical symptoms in humans. The aim of our study was to interpolate the species range for every described Anisakis species on the basis of the existing occurrence data. We used sequence data of 373 Anisakis larvae from 30 different hosts worldwide and previously published molecular data (n = 584 from 53 field-specific publications to model the species range of Anisakis spp., using a interpolation method that combines aspects of the alpha hull interpolation algorithm as well as the conditional interpolation approach. The results of our approach strongly indicate the existence of species-specific distribution patterns of Anisakis spp. within different climate zones and oceans that are in principle congruent with those of their respective final hosts. Our results support preceding studies that propose anisakid nematodes as useful biological indicators for their final host distribution and abundance as they closely follow the trophic relationships among their successive hosts. The modeling might although be helpful for predicting the likelihood of infection in order to reduce the risk of anisakiasis cases in a given area.

  7. Parasitic Nematode Interactions with Mammals and Plants

    NARCIS (Netherlands)

    Jasmer, D.P.; Goverse, A.; Smant, G.

    2003-01-01

    Parasitic nematodes that infect humans, animals, and plants cause serious diseases that are deleterious to human health and agricultural productivity. Chemical and biological control methods have reduced the impact of these parasites. However, surviving environmental stages lead to persistent

  8. Transgenesis in the parasitic nematode Strongyloides ratti.

    Science.gov (United States)

    Li, Xinshe; Shao, Hongguang; Junio, Ariel; Nolan, Thomas J; Massey, Holman C; Pearce, Edward J; Viney, Mark E; Lok, James B

    2011-10-01

    Strongyloides and related genera are advantageous subjects for transgenesis in parasitic nematodes, primarily by gonadal microinjection as has been used with Caenorhabditis elegans. Transgenesis has been achieved in Strongyloides stercoralis and in Parastrongyloides trichosuri, but both of these lack well-adapted, conventional laboratory hosts in which to derive transgenic lines. By contrast, Strongyloides ratti develops in laboratory rats with high efficiency and offers the added advantages of robust genomic and transcriptomic databases and substantial volumes of genetic, developmental and immunological data. Therefore, we evaluated methodology for transgenesis in S. stercoralis as a means of transforming S. ratti. S. stercoralis-based GFP reporter constructs were expressed in a proportion of F1 transgenic S. ratti following gonadal microinjection into parental free-living females. Frequencies of transgene expression in S. ratti, ranged from 3.7% for pAJ09 to 6.8% for pAJ20; respective frequencies for these constructs in S. stercoralis were 5.6% and 33.5%. Anatomical patterns of transgene expression were virtually identical in S. ratti and S. stercoralis. This is the first report of transgenesis in S. ratti, an important model organism for biological investigations of parasitic nematodes. Availability of the rat as a well-adapted laboratory host will facilitate derivation of transgenic lines of this parasite. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Bioinformatic identification of cytochrome b5 homologues from the parasitic nematode Ascaris suum and the free-living nematode Caenorhabditis elegans highlights the crucial role of A. suum adult-specific secretory cytochrome b₅ in parasitic adaptation.

    Science.gov (United States)

    Takamiya, Shinzaburo; Hashimoto, Muneaki; Mita, Toshihiro; Yokota, Takehiro; Nakajima, Yoshitaka; Yamakura, Fumiyuki; Sugio, Shigetoshi; Fujimura, Tsutomu; Ueno, Takashi; Yamasaki, Hiroshi

    2016-04-01

    We previously reported that adult Ascaris suum possesses NADH-metmyoglobin and NADH-methaemoglobin reductase systems that are located in the cells of the body wall and in the extracellular perienteric fluid, respectively, which helps them adapt to environmental hypoxia by recovering the differential functions of myoglobin and haemoglobin. A. suum cytochrome b5, an adult-specific secretory protein and an essential component of the NADH-metmyo (haemo) globin reductase system, has been extensively studied, and its unique nature has been determined. However, the relationship between A. suum cytochrome b5 and the canonical cytochrome b5 proteins, from the free-living nematode Caenorhabditis elegans is unclear. Here, we have characterised four cytochrome b5-like proteins from C. elegans (accession numbers: CAB01732, CCD68984, CAJ58492, and CAA98498) and three from A. suum (accession numbers: ADY48796, ADY46277, and ADY48338) and compared them with A. suum cytochrome b5 in silico. Bioinformatic and molecular analyses showed that CAA98498 from C. elegans is equivalent of A. suum cytochrome b5, which was not expressed as a mature mRNA. Further, the CAA98498 possessed no secretory signal peptide, which occurs in A. suum cytochrome b5 precursor. These results suggest that this free-living nematode does not need a haemoprotein such as the A. suum cytochrome b5 and highlight the crucial function of this A. suum adult-specific secretory cytochrome b5 in parasitic adaptation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Transgenesis and neuronal ablation in parasitic nematodes: revolutionary new tools to dissect host–parasite interactions

    Science.gov (United States)

    Lok, J. B.; Artis, D.

    2011-01-01

    SUMMARY Ease of experimental gene transfer into viral and prokaryotic pathogens has made transgenesis a powerful tool for investigating the interactions of these pathogens with the host immune system. Recent advances have made this approach feasible for more complex protozoan parasites. By contrast, the lack of a system for heritable transgenesis in parasitic nematodes has hampered progress toward understanding the development of nematode-specific cellular responses. Recently, however, significant strides towards such a system have been made in several parasitic nematodes, and the possible applications of these in immunological research should now be contemplated. In addition, methods for targeted cell ablation have been successfully adapted from Caenorhabditis elegans methodology and applied to studies of neurobiology and behaviour in Strongyloides stercoralis. Together, these new technical developments offer exciting new tools to interrogate multiple aspects of the host–parasite interaction following nematode infection. PMID:18324923

  11. Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants.

    Science.gov (United States)

    Silvestre, A; Cabaret, J

    2004-06-01

    In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control)? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation) are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole). Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy) are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial: it is not possible to avoid it, but only to delay its development in farm animal industry.

  12. Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants

    Directory of Open Access Journals (Sweden)

    Silvestre A.

    2004-06-01

    Full Text Available In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control ? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole. Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial : it is not possible to avoid it, but only to delay its development in farm animal industry.

  13. Cell cycle activation by plant parasitic nematodes

    NARCIS (Netherlands)

    Goverse, A.; Almeida Engler, de J.; Verhees, J.; Krol, van der S.; Helder, J.; Gheysen, G.

    2000-01-01

    Sedentary nematodes are important pests of crop plants. They are biotrophic parasites that can induce the (re)differentiation of either differentiated or undifferentiated plant cells into specialized feeding cells. This (re)differentiation includes the reactivation of the cell cycle in specific

  14. Prevalence of parasitic gastrointestinal nematodes of small ...

    African Journals Online (AJOL)

    A cross-sectional study was conducted from December, 2014 to May, 2015 on 914 animals (345 sheep and 569 goats) at Jalingo abattoir, Taraba State, Nigeria based on faecal examination. The objective of the study was to determine the prevalence rate of parasitic gastrointestinal nematodes in slaughtered small ...

  15. Smart Parasitic Nematodes Use Multifaceted Strategies to Parasitize Plants

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    Muhammad A. Ali

    2017-10-01

    Full Text Available Nematodes are omnipresent in nature including many species which are parasitic to plants and cause enormous economic losses in various crops. During the process of parasitism, sedentary phytonematodes use their stylet to secrete effector proteins into the plant cells to induce the development of specialized feeding structures. These effectors are used by the nematodes to develop compatible interactions with plants, partly by mimicking the expression of host genes. Intensive research is going on to investigate the molecular function of these effector proteins in the plants. In this review, we have summarized which physiological and molecular changes occur when endoparasitic nematodes invade the plant roots and how they develop a successful interaction with plants using the effector proteins. We have also mentioned the host genes which are induced by the nematodes for a compatible interaction. Additionally, we discuss how nematodes modulate the reactive oxygen species (ROS and RNA silencing pathways in addition to post-translational modifications in their own favor for successful parasitism in plants.

  16. Remote Sensing of Parasitic Nematodes in Plants

    Science.gov (United States)

    Lawrence, Gary W.; King, Roger; Kelley, Amber T.; Vickery, John

    2007-01-01

    A method and apparatus for remote sensing of parasitic nematodes in plants, now undergoing development, is based on measurement of visible and infrared spectral reflectances of fields where the plants are growing. Initial development efforts have been concentrated on detecting reniform nematodes (Rotylenchulus reniformis) in cotton plants, because of the economic importance of cotton crops. The apparatus includes a hand-held spectroradiometer. The readings taken by the radiometer are processed to extract spectral reflectances at sixteen wavelengths between 451 and 949 nm that, taken together, have been found to be indicative of the presence of Rotylenchulus reniformis. The intensities of the spectral reflectances are used to estimate the population density of the nematodes in an area from which readings were taken.

  17. Adaptive immunity alters distinct host feeding pathways during nematode induced inflammation, a novel mechanism in parasite expulsion.

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    John J Worthington

    2013-01-01

    Full Text Available Gastrointestinal infection is often associated with hypophagia and weight loss; however, the precise mechanisms governing these responses remain poorly defined. Furthermore, the possibility that alterations in feeding during infection may be beneficial to the host requires further study. We used the nematode Trichinella spiralis, which transiently inhabits the small intestine before migrating to skeletal muscle, as a biphasic model of infection to determine the cellular and molecular pathways controlling feeding during enteric and peripheral inflammation. Through the infection of genetically modified mice lacking cholecystokinin, Tumor necrosis factor α receptors and T and B-cells, we observed a biphasic hypophagic response to infection resulting from two separate immune-driven mechanisms. The enteroendocrine I-cell derived hormone cholecystokinin is an essential mediator of initial hypophagia and is induced by CD4+ T-cells during enteritis. In contrast, the second hypophagic response is extra-intestinal and due to the anorectic effects of TNFα during peripheral infection of the muscle. Moreover, via maintaining naive levels of the adipose secreted hormone leptin throughout infection we demonstrate a novel feedback loop in the immunoendocrine axis. Immune driven I-cell hyperplasia and resultant weight loss leads to a reduction in the inflammatory adipokine leptin, which in turn heightens protective immunity during infection. These results characterize specific immune mediated mechanisms which reduce feeding during intestinal or peripheral inflammation. Importantly, the molecular mediators of each phase are entirely separate. The data also introduce the first evidence that I-cell hyperplasia is an adaptively driven immune response that directly impinges on the outcome to infection.

  18. Transgenesis in parasitic nematodes: building a better array

    OpenAIRE

    Lok, James B.

    2009-01-01

    In spite of recent progress in the development of transgenesis in parasitic nematodes, several impediments remain before this methodology can become a practical and widely employed tool in parasitology. Recently published studies on transgenesis in the necromenic nematode Pristionchus pacificus from the laboratory of Ralf Sommer highlight several leads that might be valuable as efforts to refine current systems in obligate parasites go forward.

  19. Cloning and characterization of hypoxia-inducible factor-1 subunits from Ascaris suum - a parasitic nematode highly adapted to changes of oxygen conditions during its life cycle.

    Science.gov (United States)

    Goto, Miho; Amino, Hisako; Nakajima, Mikage; Tsuji, Naotoshi; Sakamoto, Kimitoshi; Kita, Kiyoshi

    2013-03-01

    The parasitic nematode Ascaris suum successfully adapts to a significant decrease in oxygen availability during its life cycle by altering its metabolic system dramatically. However, little is known about the regulatory mechanisms of adaptation to hypoxic environments in A. suum. In multicellular organisms, hypoxia-inducible factor-1 (HIF-1), a heterodimeric transcription factor composed of HIF-1α and HIF-1β subunits, is a master regulator of genes involved in adaptation to hypoxia. In the present study, cDNAs encoding HIF-1α and HIF-1β were cloned from A. suum and characterized. The full-length A. suum hif-1α and hif-1β cDNAs contain open reading frames encoding proteins with 832 and 436 amino acids, respectively. In the deduced amino acid sequences of A. suum HIF-1α and HIF-1β, functional domains essential for DNA-binding, dimerization, and oxygen-dependent prolyl hydroxylation were conserved. The interaction between A. suum HIF-1α and HIF-1β was confirmed by the yeast two-hybrid assay. Both A. suum hif-1α and hif-1β mRNAs were expressed at all stages examined (fertilized eggs, third-stage larvae, lung-stage larvae, young adult worms, and adult muscle tissue), and most abundantly in the aerobic free-living third-stage larvae, followed by a gradual decrease after infection of the host. hif-1 mRNA transcription was not sensitive to the oxygen environment in either third-stage larvae or adult worms (muscle tissue), and was regulated in a stage-specific manner. High expression of hif-1 mRNAs in third-stage larvae suggests its contribution to pre-adaptation to a hypoxic environment after infection of their host. Sequence analysis of 5'-upstream regions of mitochondrial complex II (succinate-ubiquinone reductase/quinol-fumarate reductase) genes, which show stage-specific expression and play an important role in oxygen adaptation during the life cycle, revealed that all subunits except for the adult-type flavoprotein subunit (Fp) possess putative hypoxia

  20. Targeted mutagenesis in a human-parasitic nematode.

    Directory of Open Access Journals (Sweden)

    Spencer S Gang

    2017-10-01

    Full Text Available Parasitic nematodes infect over 1 billion people worldwide and cause some of the most common neglected tropical diseases. Despite their prevalence, our understanding of the biology of parasitic nematodes has been limited by the lack of tools for genetic intervention. In particular, it has not yet been possible to generate targeted gene disruptions and mutant phenotypes in any parasitic nematode. Here, we report the development of a method for introducing CRISPR-Cas9-mediated gene disruptions in the human-parasitic threadworm Strongyloides stercoralis. We disrupted the S. stercoralis twitchin gene unc-22, resulting in nematodes with severe motility defects. Ss-unc-22 mutations were resolved by homology-directed repair when a repair template was provided. Omission of a repair template resulted in deletions at the target locus. Ss-unc-22 mutations were heritable; we passed Ss-unc-22 mutants through a host and successfully recovered mutant progeny. Using a similar approach, we also disrupted the unc-22 gene of the rat-parasitic nematode Strongyloides ratti. Our results demonstrate the applicability of CRISPR-Cas9 to parasitic nematodes, and thereby enable future studies of gene function in these medically relevant but previously genetically intractable parasites.

  1. Microsatellite diversity of isolates of the parasitic nematode Haemonchus contortus

    NARCIS (Netherlands)

    Otsen, M.; Plas, M. E.; Lenstra, J. A.; Roos, M. H.; Hoekstra, R.

    2000-01-01

    The alarming development of anthelmintic resistance in important gastrointestinal nematode parasites of man and live-stock is caused by selection for specific genotypes. In order to provide genetic tools to study the nematode populations and the consequences of anthelmintic treatment, we isolated

  2. Occurence of plant parasitic nematodes and factors that enhance ...

    African Journals Online (AJOL)

    Plant parasitic nematodes remain a major challenge to crop production that has hitherto received minmum research attention in sub-Saharan Africa. This paper gives the diversity of nematode genera and species associated with cereal crops and indicates the possibility of nemadode population build up due to production ...

  3. occurrence of plant parasitic nematodes and factors that enhance ...

    African Journals Online (AJOL)

    Administrator

    Plant parasitic nematodes remain a major challenge to crop production that has hitherto received minmum research attention in sub-Saharan Africa. This paper gives the diversity of nematode genera and species associ- ated with cereal crops and indicates the possibility of nemadode population build up due to production ...

  4. Transgenesis in parasitic nematodes: building a better array

    Science.gov (United States)

    Lok, James B.

    2011-01-01

    In spite of recent progress in the development of transgenesis in parasitic nematodes, several impediments remain before this methodology can become a practical and widely employed tool in parasitology. Recently published studies on transgenesis in the necromenic nematode Pristionchus pacificus from the laboratory of Ralf Sommer highlight several leads that might be valuable as efforts to refine current systems in obligate parasites go forward. PMID:19617000

  5. Developmental plasticity and the evolution of parasitism in an unusual nematode, Parastrongyloides trichosuri

    Directory of Open Access Journals (Sweden)

    Stasiuk Susan J

    2012-01-01

    Full Text Available Abstract Background Parasitism is an important life history strategy in many metazoan taxa. This is particularly true of the Phylum Nematoda, in which parasitism has evolved independently at least nine times. The apparent ease with which parasitism has evolved amongst nematodes may, in part, be due to a feature of nematode development acting as a pre-adaptation for the transition from a free-living to a parasitic life history. One candidate pre-adaptive feature for evolution in terrestrial nematodes is the dauer larva, a developmentally arrested morph formed in response to environmental signals. Results We investigated the role of dauer development in the nematode, Parastrongyloides trichosuri, which has retained a complete free-living life cycle in addition to a life cycle as a mammalian gastrointestinal parasite. We show that the developmental switch between these life histories is sensitive to the same environmental cues as dauer arrest in free-living nematodes, including sensitivity to a chemical cue produced by the free-living stages. Furthermore, we show that genetic variation for the sensitivity of the cue(s exists in natural populations of P. trichosuri, such that we derived inbred lines that were largely insensitive to the cue and other lines that were supersensitive to the cue. Conclusions For this parasitic clade, and perhaps more widely in the phylum, the evolution of parasitism co-opted the dauer switch of a free-living ancestor. This lends direct support to the hypothesis that the switch to developmental arrest in the dauer larva acted as a pre-adaptation for the evolution of parasitism, and suggests that the sensory transduction machinery downstream of the cue may have been similarly co-opted and modified.

  6. Top 10 plant-parasitic nematodes in molecular plant pathology.

    Science.gov (United States)

    Jones, John T; Haegeman, Annelies; Danchin, Etienne G J; Gaur, Hari S; Helder, Johannes; Jones, Michael G K; Kikuchi, Taisei; Manzanilla-López, Rosa; Palomares-Rius, Juan E; Wesemael, Wim M L; Perry, Roland N

    2013-12-01

    The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a 'top 10' list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. However, care was taken to include researchers from as many parts of the world as possible when carrying out the survey. The top 10 list emerging from the survey is composed of: (1) root-knot nematodes (Meloidogyne spp.); (2) cyst nematodes (Heterodera and Globodera spp.); (3) root lesion nematodes (Pratylenchus spp.); (4) the burrowing nematode Radopholus similis; (5) Ditylenchus dipsaci; (6) the pine wilt nematode Bursaphelenchus xylophilus; (7) the reniform nematode Rotylenchulus reniformis; (8) Xiphinema index (the only virus vector nematode to make the list); (9) Nacobbus aberrans; and (10) Aphelenchoides besseyi. The biology of each nematode (or nematode group) is reviewed briefly. © 2013 BSPP AND JOHN WILEY & SONS LTD.

  7. Nucleic acid transfection and transgenesis in parasitic nematodes.

    Science.gov (United States)

    Lok, James B

    2012-04-01

    Transgenesis is an essential tool for assessing gene function in any organism, and it is especially crucial for parasitic nematodes given the dwindling armamentarium of effective anthelmintics and the consequent need to validate essential molecular targets for new drugs and vaccines. Two of the major routes of gene delivery evaluated to date in parasitic nematodes, bombardment with DNA-coated microparticles and intragonadal microinjection of DNA constructs, draw upon experience with the free-living nematode Caenorhabditis elegans. Bombardment has been used to transiently transfect Ascaris suum, Brugia malayi and Litomosoides sigmodontis with both RNA and DNA. Microinjection has been used to achieve heritable transgenesis in Strongyloides stercoralis, S. ratti and Parastrongyloides trichosuri and for additional transient expression studies in B. malayi. A third route of gene delivery revisits a classic method involving DNA transfer facilitated by calcium-mediated permeabilization of recipient cells in developing B. malayi larvae and results in transgene inheritance through host and vector passage. Assembly of microinjected transgenes into multi-copy episomal arrays likely results in their transcriptional silencing in some parasitic nematodes. Methods such as transposon-mediated transgenesis that favour low-copy number chromosomal integration may remedy this impediment to establishing stable transgenic lines. In the future, stable transgenesis in parasitic nematodes could enable loss-of-function approaches by insertional mutagenesis, in situ expression of inhibitory double-stranded RNA or boosting RNAi susceptibility through heterologous expression of dsRNA processing and transport proteins.

  8. Parasitic nematodes in the chimpanzee population on Rubondo Island, Tanzania

    Czech Academy of Sciences Publication Activity Database

    Petrželková, Klára Judita; Hasegawa, H.; Moscovice, L. R.; Kaur, T.; Issa, M. H.; Huffman, M. A.

    2006-01-01

    Roč. 27, č. 3 (2006), s. 767-777 ISSN 0164-0291 Institutional research plan: CEZ:AV0Z60930519 Keywords : chimpanzee * introduced population * nematode * new parasite record * Rubondo Island Subject RIV: EG - Zoology Impact factor: 1.331, year: 2006

  9. Top 10 plant-parasitic nematodes in molecular plant pathology

    NARCIS (Netherlands)

    Jones, J.T.; Haegeman, A.; Danchin, E.G.J.; Gaur, H.S.; Helder, J.; Jones, M.G.K.; Kikuchi, T.; Manzanilla-López, R.; Palomares-Rius, J.E.; Wesemael, W.M.L.; Perry, R.N.

    2013-01-01

    The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a ‘top 10’ list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region

  10. RNA interference in plant parasitic nematodes | Karakas | African ...

    African Journals Online (AJOL)

    Conserved in most eukaryotic organisms, the RNAi pathway is thought to have evolved as a form of innate immunity against viruses and also plays a major role in regulating development and genome maintenance. RNAi has recently been demonstrated in plant parasitic nematodes. It is a potentially powerful investigative ...

  11. Nematodes Parasites of Teiid Lizards from the Brazilian Amazon Rainforest.

    Science.gov (United States)

    Macedo, L C; Gardner, S L; Melo, F T V; Giese, E G; Santos, J N

    2017-04-01

    This study presents the helminth composition and parameters of infection by several species of nematodes in teiid lizards, Ameiva ameiva ameiva (Linnaeus, 1758), Cnemidophorus cryptus Cole and Dessauer, 1993, and Kentropyx calcarata Spix, 1825 from the Brazilian Amazonian Rainforest. The population of lizards studied were parasitized by 6 species of Phylum Nemata including: Spinicauda spinicauda (Olfers, 1919), Parapharyngodon alvarengai Freitas, 1957, Physaloptera sp. (adults), Physaloptera sp. (larvae), Piratuba digiticauda Lent and Freitas, 1941, and Anisakidae (larvae). The overall prevalence was 66.17% and the mean intensity of infection was 19.40 ± 25.48. The association between the body-length of lizards and the abundance and richness of parasitic nematodes was statistically significant only in Ameiva a. ameiva. A new host record is reported here with 1 specimen of the family Anasakidae in Ameiva a. ameiva. Both S. spinicauda and Physaloptera sp. represent new records from C. cryptus.

  12. Can parasites halt the invader? Mermithid nematodes parasitizing the yellow-legged Asian hornet in France

    Directory of Open Access Journals (Sweden)

    Claire Villemant

    2015-05-01

    Full Text Available Since its introduction in France 10 years ago, the yellow-legged Asian bee-hawking hornet Vespa velutina has rapidly spread to neighboring countries (Spain, Portugal, Belgium, Italy, and Germany, becoming a new threat to beekeeping activities. While introduced species often leave behind natural enemies from their original home, which benefits them in their new environment, they can also suffer local recruitment of natural enemies. Three mermithid parasitic subadults were obtained from V. velutina adults in 2012, from two French localities. However, these were the only parasitic nematodes reported up to now in Europe, in spite of the huge numbers of nests destroyed each year and the recent examination of 33,000 adult hornets. This suggests that the infection of V. velutina by these nematodes is exceptional. Morphological criteria assigned the specimens to the genus Pheromermis and molecular data (18S sequences to the Mermithidae, due to the lack of Pheromermis spp. sequences in GenBank. The species is probably Pheromermis vesparum, a parasite of social wasps in Europe. This nematode is the second native enemy of Vespa velutina recorded in France, after a conopid fly whose larvae develop as internal parasitoids of adult wasps and bumblebees. In this paper, we provide arguments for the local origin of the nematode parasite and its limited impact on hornet colony survival. We also clarify why these parasites (mermithids and conopids most likely could not hamper the hornet invasion nor be used in biological control programs against this invasive species.

  13. Practical application of insect-parasitic nematodes and sterile flies

    International Nuclear Information System (INIS)

    Galle, F.; Loosjes, M.

    1987-01-01

    The company 'de Groene Vlieg' started with commercial control of the onion fly by means of the sterile insect technique. At the moment 10 per cent of the Dutch spring sown onions are treated with this method. The mass-rearing, the estimations of populations and the repeated releases of sterilized flies make it a rather complicated method. It can be applied economically per field, but only in areas with a concentration of onion growing. For export we see no possibilities yet. In principle the sterile insect technique can be applied also to other flies (carrot rust fly, cabbage root fly), but a suitable artificial diet is still lacking. Since some years we also rear the insect parasitic nematodes Heterorhabditis sp. and Neoaplectana bibionis. The later is experimentally used with success against Agrotis segetum caterpillars in lettuce. Research will yield more applications of nematodes against different pests. We use Heterorhabditis sp. in practice against the black vine weevil (Otiorhynchus sulcatus), a serious pest in glass houses, tree nurseries and gardens. Good control is achieved with a dose of one half to one million nematodes per square meter in moist soil and with temperatures above 12 degrees C. The application is similar to that of a chemical insecticide. The pest is killed by symbiontic bacteria, released by the nematodes after penetrating into the body cavity of the larvae. The nematodes are delivered by mail. If cooled they can be kept alive for over four weeks in the package. We export already to Switzerland and plan to export also to Western Germany. At this moment a possible admittance is under investigation in the Netherlands for application of a nuclear polyhedrosis virus against Spodoptera exigua caterpillars

  14. Microsporidia are natural intracellular parasites of the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Troemel, Emily R; Félix, Marie-Anne; Whiteman, Noah K; Barrière, Antoine; Ausubel, Frederick M

    2008-12-09

    For decades the soil nematode Caenorhabditis elegans has been an important model system for biology, but little is known about its natural ecology. Recently, C. elegans has become the focus of studies of innate immunity and several pathogens have been shown to cause lethal intestinal infections in C. elegans. However none of these pathogens has been shown to invade nematode intestinal cells, and no pathogen has been isolated from wild-caught C. elegans. Here we describe an intracellular pathogen isolated from wild-caught C. elegans that we show is a new species of microsporidia. Microsporidia comprise a large class of eukaryotic intracellular parasites that are medically and agriculturally important, but poorly understood. We show that microsporidian infection of the C. elegans intestine proceeds through distinct stages and is transmitted horizontally. Disruption of a conserved cytoskeletal structure in the intestine called the terminal web correlates with the release of microsporidian spores from infected cells, and appears to be part of a novel mechanism by which intracellular pathogens exit from infected cells. Unlike in bacterial intestinal infections, the p38 MAPK and insulin/insulin-like growth factor (IGF) signaling pathways do not appear to play substantial roles in resistance to microsporidian infection in C. elegans. We found microsporidia in multiple wild-caught isolates of Caenorhabditis nematodes from diverse geographic locations. These results indicate that microsporidia are common parasites of C. elegans in the wild. In addition, the interaction between C. elegans and its natural microsporidian parasites provides a system in which to dissect intracellular intestinal infection in vivo and insight into the diversity of pathogenic mechanisms used by intracellular microbes.

  15. The Ditylenchus destructor genome provides new insights into the evolution of plant parasitic nematodes.

    Science.gov (United States)

    Zheng, Jinshui; Peng, Donghai; Chen, Ling; Liu, Hualin; Chen, Feng; Xu, Mengci; Ju, Shouyong; Ruan, Lifang; Sun, Ming

    2016-07-27

    Plant-parasitic nematodes were found in 4 of the 12 clades of phylum Nematoda. These nematodes in different clades may have originated independently from their free-living fungivorous ancestors. However, the exact evolutionary process of these parasites is unclear. Here, we sequenced the genome sequence of a migratory plant nematode, Ditylenchus destructor We performed comparative genomics among the free-living nematode, Caenorhabditis elegans and all the plant nematodes with genome sequences available. We found that, compared with C. elegans, the core developmental control processes underwent heavy reduction, though most signal transduction pathways were conserved. We also found D. destructor contained more homologies of the key genes in the above processes than the other plant nematodes. We suggest that Ditylenchus spp. may be an intermediate evolutionary history stage from free-living nematodes that feed on fungi to obligate plant-parasitic nematodes. Based on the facts that D. destructor can feed on fungi and has a relatively short life cycle, and that it has similar features to both C. elegans and sedentary plant-parasitic nematodes from clade 12, we propose it as a new model to study the biology, biocontrol of plant nematodes and the interaction between nematodes and plants. © 2016 The Author(s).

  16. Observations on some nematodes parasitic in freshwater fishes in Laos.

    Science.gov (United States)

    Moravec, F; Scholz, T

    1991-01-01

    In 1989, samples of some freshwater fishes collected in Vientiane Province (R. Mekong basin) in Laos were examined for helminths. This material comprised 11 species of parasitic nematodes (7 adults and 4 larvae), including 3 species new to science: Camallanus (Camallanus) hampalae sp. n. from Hampala macrolepidota, Procamallanus (Punctocamallanus) punctatus sp. n. from Mystus rhegma and Mystus sp., and Rhabdochona (Globochona) equispiculata sp. n. from Hampala macrolepidota and H. dispar. Zeylanema Yeh, 1960 is considered a subgenus of the genus Camallanus, Dentocamallanus subgen. n. (type species C. (D.) sweeti (Moorthy, 1937)) is proposed for the species of Paracamallanus with teeth in the buccal capsule, and Punctocamallanus subgen. n. (type species P. (P.) punctatus sp. n.) for the species of Procamallanus with the buccal capsule ornamented with punctations. The name Rhabdochona wangi nom. nov. is proposed for R. bagarii Wang et Guo, 1983 (a homonym to R. bagarii Gupta et Srivastava, 1982) and Camallanus gomtii Gupta et Verma, 1978 is newly synonymized with Neocamallanus ophiocephali (Pearse, 1933). All the nematodes are recorded from Laos for the first time. The parasites are briefly described and illustrated and some problems concerning their taxonomy and geographical distribution are discussed.

  17. Exploring the host parasitism of the migratory plant-parasitic nematode Ditylenchus destuctor by expressed sequence tags analysis.

    Directory of Open Access Journals (Sweden)

    Huan Peng

    Full Text Available The potato rot nematode, Ditylenchus destructor, is a very destructive nematode pest on many agriculturally important crops worldwide, but the molecular characterization of its parasitism of plant has been limited. The effectors involved in nematode parasitism of plant for several sedentary endo-parasitic nematodes such as Heterodera glycines, Globodera rostochiensis and Meloidogyne incognita have been identified and extensively studied over the past two decades. Ditylenchus destructor, as a migratory plant parasitic nematode, has different feeding behavior, life cycle and host response. Comparing the transcriptome and parasitome among different types of plant-parasitic nematodes is the way to understand more fully the parasitic mechanism of plant nematodes. We undertook the approach of sequencing expressed sequence tags (ESTs derived from a mixed stage cDNA library of D. destructor. This is the first study of D. destructor ESTs. A total of 9800 ESTs were grouped into 5008 clusters including 3606 singletons and 1402 multi-member contigs, representing a catalog of D. destructor genes. Implementing a bioinformatics' workflow, we found 1391 clusters have no match in the available gene database; 31 clusters only have similarities to genes identified from D. africanus, the most closely related species to D. destructor; 1991 clusters were annotated using Gene Ontology (GO; 1550 clusters were assigned enzyme commission (EC numbers; and 1211 clusters were mapped to 181 KEGG biochemical pathways. 22 ESTs had similarities to reported nematode effectors. Interestedly, most of the effectors identified in this study are involved in host cell wall degradation or modification, such as 1,4-beta-glucanse, 1,3-beta-glucanse, pectate lyase, chitinases and expansin, or host defense suppression such as calreticulin, annexin and venom allergen-like protein. This result implies that the migratory plant-parasitic nematode D. destructor secrets similar effectors to

  18. RNA Interference: A Novel Source of Resistance to Combat Plant Parasitic Nematodes

    Directory of Open Access Journals (Sweden)

    Sagar Banerjee

    2017-05-01

    Full Text Available Plant parasitic nematodes cause severe damage and yield loss in major crops all over the world. Available control strategies include use of insecticides/nematicides but these have proved detrimental to the environment, while other strategies like crop rotation and resistant cultivars have serious limitations. This scenario provides an opportunity for the utilization of technological advances like RNA interference (RNAi to engineer resistance against these devastating parasites. First demonstrated in the model free living nematode, Caenorhabtidis elegans; the phenomenon of RNAi has been successfully used to suppress essential genes of plant parasitic nematodes involved in parasitism, nematode development and mRNA metabolism. Synthetic neurotransmitants mixed with dsRNA solutions are used for in vitro RNAi in plant parasitic nematodes with significant success. However, host delivered in planta RNAi has proved to be a pioneering phenomenon to deliver dsRNAs to feeding nematodes and silence the target genes to achieve resistance. Highly enriched genomic databases are exploited to limit off target effects and ensure sequence specific silencing. Technological advances like gene stacking and use of nematode inducible and tissue specific promoters can further enhance the utility of RNAi based transgenics against plant parasitic nematodes.

  19. Colitis promotes adaptation of an intestinal nematode: a Heligmosomoides polygyrus mouse model system.

    Directory of Open Access Journals (Sweden)

    Katarzyna Donskow-Łysoniewska

    Full Text Available The precise mechanism of the very effective therapeutic effect of gastrointestinal nematodes on some autoimmune diseases is not clearly understood and is currently being intensively investigated. Treatment with living helminths has been initiated to reverse intestinal immune-mediated diseases in humans. However, little attention has been paid to the phenotype of nematodes in the IBD-affected gut and the consequences of nematode adaptation. In the present study, exposure of Heligmosomoides polygyrus larvae to the changed cytokine milieu of the intestine during colitis reduced inflammation in an experimental model of dextran sulphate sodium (DSS- induced colitis, but increased nematode establishment in the moderate-responder BALB/c mouse strain. We used mass spectrometry in combination with two-dimensional Western blotting to determine changes in protein expression and changes in nematode antigens recognized by IgG1 in mice with colitis. We show that nematode larvae immunogenicity is changed by colitis as soon as 6 days post-infection; IgG1 did not recognize highly conserved proteins Lev-11 (isoform 1 of tropomyosin α1 chain, actin-4 isoform or FTT-2 isoform a (14-3-3 family protein. These results indicate that changes in the small intestine provoked by colitis directly influence the nematode proteome. The unrecognized proteins seem to be key antigenic epitopes able to induce protective immune responses. The proteome changes were associated with weak immune recognition and increased larval adaptation and worm growth, altered localization in the intestine and increased survival of males but reduced worm fecundity. In this report, the mechanisms influencing nematode survival and the consequences of changed immunogenicity that reflect the immune response at the site colonized by the parasite in mice with colitis are described. The results are relevant to the use of live parasites to ameliorate IBD.

  20. Adaptations in the energy metabolism of parasites

    NARCIS (Netherlands)

    van Grinsven, K.W.A.|info:eu-repo/dai/nl/304833436

    2009-01-01

    For this thesis fundamental research was performed on the metabolic adaptations found in parasites. Studying the adaptations in parasite metabolisms leads to a better understanding of parasite bioenergetics and can also result in the identification of new anti-parasitic drug targets. We focussed on

  1. The Activation and Suppression of Plant Innate Immunity by Parasitic Nematodes

    NARCIS (Netherlands)

    Goverse, A.; Smant, G.

    2014-01-01

    Plant-parasitic nematodes engage in prolonged and intimate relationships with their host plants, often involving complex alterations in host cell morphology and function. It is puzzling how nematodes can achieve this, seemingly without activating the innate immune system of their hosts. Secretions

  2. Plant parasitic nematodes associated with Indian Pennywort Centella asiatica (L. Urban in Manipur

    Directory of Open Access Journals (Sweden)

    N.R. Devi

    2009-12-01

    Full Text Available A survey of the plant parasitic nematodes associated with Centella asiatica (L. Urban was conducted in different localities of Manipur. Twenty one species of plant parasitic nematodes belonging to 12 genera were found to occur. Tylenchorhynelms mashhoodi, Aphelenchus avenae and Helicotylenchus dihystera were predominant with absolute densities ranging from 338 - 498 per 500g soil. Basiria varians and T.mashhoodi were recorded with highest absolute frequency and absolute density respectively.

  3. Survey and effects of plant parasitic root nematodes of cashew ...

    African Journals Online (AJOL)

    . Five thousand, one hundred and twenty cashew trees were sampled and nematodes in their rhizospheres extracted by modified Cobb's decanting and sieving technique. Pure cultures of the nematodes were further inoculated on 30 days old ...

  4. Mating clusters in the mosquito parasitic nematode, Strelkovimermis spiculatus.

    Science.gov (United States)

    Dong, Limin; Sanad, Manar; Wang, Yi; Xu, Yanli; Shamseldean, Muhammad S M; Gaugler, Randy

    2014-03-01

    Mating aggregations in the mosquito parasitic nematode, Strelkovimermis spiculatus, were investigated in the laboratory. Female postparasites, through their attraction of males and, remarkably, other females, drive the formation of mating clusters. Clusters may grow in size by merging with other individual or clusters. Female molting to the adult stage and reproductive success are enhanced in larger clusters. Male mating behavior is initiated when the female begins to molt to the adult stage by shedding dual juvenile cuticles posteriorly. Males coil their tail around the adult cuticle, migrating progressively along the female in intimate synchrony with the molting cuticle until the vulva is exposed and mating can occur. The first arriving male is assured of access to a virgin female, as his intermediate location between the vulva and subsequently arriving males blocks these competitors. Males deposit an adhesive gelatinous copulatory plug into and over the vulva before departing the female. Fecundity was greater in larger mating clusters, but this was a function of a greater rate of molting which is a prerequisite for mating. Males compete for virgin females by emerging and molting to the adult stage earlier than females. Mating aggregations have previously only been examined in snakes, but these studies have tended to be observational as snakes offer a challenging system for study. The relatively easy to culture and manipulate mermithid system may offer a model for experimental studies of male-male competition, protandry, copulatory plugs and female choice in mating clusters. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. In vitro proteolysis of nematode FLPs by preparations from the free-living nematode Panagrellus redivivus and two plant-parasitic nematodes (Heterodera glycines and Meloidogyne incognita)

    Science.gov (United States)

    Proteolytic activities in extracts from three nematodes, the plant parasites Heterodera glycines and Meloidogyne incognita, and the free-living Panagrellus redivivus, were surveyed for substrate preferences using a battery of seven FRET-modified peptide substrates, all derived from members of the la...

  6. Msp40 effector of root-knot nematode manipulates plant immunity to facilitate parasitism.

    Science.gov (United States)

    Niu, Junhai; Liu, Pei; Liu, Qian; Chen, Changlong; Guo, Quanxin; Yin, Junmei; Yang, Guangsui; Jian, Heng

    2016-01-22

    Root-knot nematodes (RKNs) are obligate biotrophic parasites that invade plant roots and engage in prolonged and intimate relationships with their hosts. Nematode secretions, some of which have immunosuppressing activity, play essential roles in successful parasitism; however, their mechanisms of action remain largely unknown. Here, we show that the RKN-specific gene MiMsp40, cloned from Meloidogyne incognita, is expressed exclusively in subventral oesophageal gland cells and is strongly upregulated during early parasitic stages. Arabidopsis plants overexpressing MiMsp40 were more susceptible to nematode infection than were wild type plants. Conversely, the host-derived MiMsp40 RNAi suppressed nematode parasitism and/or reproduction. Moreover, overexpression of MiMsp40 in plants suppressed the deposition of callose and the expression of marker genes for bacterial elicitor elf18-triggered immunity. Transient expression of MiMsp40 prevented Bax-triggered defence-related programmed cell death. Co-agroinfiltration assays indicated that MiMsp40 also suppressed macroscopic cell death triggered by MAPK cascades or by the ETI cognate elicitors R3a/Avr3a. Together, these results demonstrate that MiMsp40 is a novel Meloidogyne-specific effector that is injected into plant cells by early parasitic stages of the nematode and that plays a role in suppressing PTI and/or ETI signals to facilitate RKN parasitism.

  7. Nematode effector proteins: an emerging paradigm of parasitism

    Science.gov (United States)

    Phytonematodes use a stylet and secreted effectors to invade host tissues and extract nutrients to support their growth and development. The molecular function of nematode effectors is currently the subject of intense investigation. In this review, we summarize our current understanding of nematode ...

  8. The discovery of fluazaindolizine: A new product for the control of plant parasitic nematodes.

    Science.gov (United States)

    Lahm, George P; Desaeger, Johan; Smith, Ben K; Pahutski, Thomas F; Rivera, Michel A; Meloro, Tony; Kucharczyk, Roman; Lett, Renee M; Daly, Anne; Smith, Brenton T; Cordova, Daniel; Thoden, Tim; Wiles, John A

    2017-04-01

    Fluazaindolizine is a new highly effective and selective product for the control of plant parasitic nematodes. Specificity for nematodes coupled with absence of activity against the target sites of commercial nematicides suggests that fluazaindolizine has a novel mode of action. The discovery, structure-activity development and biological properties for this new class of nematicides are presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Exploitation of FTA cartridges for the sampling, long-term storage, and DNA-based analyses of plant-parasitic nematodes.

    Science.gov (United States)

    Marek, Martin; Zouhar, Miloslav; Douda, Ondřej; Maňasová, Marie; Ryšánek, Pavel

    2014-03-01

    The use of DNA-based analyses in molecular plant nematology research has dramatically increased over recent decades. Therefore, the development and adaptation of simple, robust, and cost-effective DNA purification procedures are required to address these contemporary challenges. The solid-phase-based approach developed by Flinders Technology Associates (FTA) has been shown to be a powerful technology for the preparation of DNA from different biological materials, including blood, saliva, plant tissues, and various human and plant microbial pathogens. In this work, we demonstrate, for the first time, that this FTA-based technology is a valuable, low-cost, and time-saving approach for the sampling, long-term archiving, and molecular analysis of plant-parasitic nematodes. Despite the complex structure and anatomical organization of the multicellular bodies of nematodes, we report the successful and reliable DNA-based analysis of nematode high-copy and low-copy genes using the FTA technology. This was achieved by applying nematodes to the FTA cards either in the form of a suspension of individuals, as intact or pestle-crushed nematodes, or by the direct mechanical printing of nematode-infested plant tissues. We further demonstrate that the FTA method is also suitable for the so-called "one-nematode-assay", in which the target DNA is typically analyzed from a single individual nematode. More surprisingly, a time-course experiment showed that nematode DNA can be detected specifically in the FTA-captured samples many years after initial sampling occurs. Collectively, our data clearly demonstrate the applicability and the robustness of this FTA-based approach for molecular research and diagnostics concerning phytonematodes; this research includes economically important species such as the stem nematode (Ditylenchus dipsaci), the sugar beet nematode (Heterodera schachtii), and the Northern root-knot nematode (Meloidogyne hapla).

  10. PLANT-PARASITIC NEMATODES ON STONE FRUITS AND CITRUS IN LEBANON

    Directory of Open Access Journals (Sweden)

    Said K. Ibrahim

    2016-06-01

    Full Text Available Ibrahim Said K., Ibrahim Azar, Christian Naser, Badran Akikki and Ludmilla Ibrahim. 2016. Plant-parasitic nematodes on stone fruits and citrus in Lebanon. Lebanese Science Journal, 17(1: 9-24. This study aimed to determine the occurrence, distribution of plant parasitic nematodes on stone fruits in Lebanon and to determine the effect of plant extracts on the mortality of several nematode species. A total of 308 soil samples were collected from five different crops. Almost all surveyed areas showed infection with nematodes. The soil infestation rate with nematodes in collected soil samples from all 10 surveyed crops ranged from 66.6 to 100%. Eighteen out of 308 soil samples were free of nematodes (5.8%. All the collected soil samples from nectarine and plum orchards were infested with nematodes (100%, followed by citrus (97.6%, apple (88.7%, pear and quince (85.7%, and cherry (81.4%. The lowest infection (66.6% was detected on almond and apricot. The level of infestation varied from one area to another and ranged between 0.1 and 28 nematodes per 1 g of soil, with the highest number obtained on cherry. Several genera were identified based on morphological characters including: root-knot nematodes (Meloidogyne spp., Tylenchulus, Xiphinema, Rotylenchus, Pratylenchus, and Longidorus. Tylenchulus and Radopholus spp. were the most common on citrus trees, whereas Pratylechus and Meloidogyne spp. were detected almost in all the samples collected from all the crops. Six chopped aromatic plants were tested in pot experiments to control nematodes population densities. The results revealed that carbofuran (nematicide was the most effective (88.48% in comparison to the plant materials. Allium sativum gave the highest control (76.52% followed by Tageta patula (72.0%, Cucurbita maxima (71.84% and Inula viscosa (63.96%. Origanum syriacum (55.04% and Thymus (53.72% were less effective in comparison to the rest of tested plant materials.

  11. Prevalence of intestinal nematode parasitism among pet dogs in the United States (2003-2006).

    Science.gov (United States)

    Mohamed, Ahmed S; Moore, George E; Glickman, Larry T

    2009-03-01

    To estimate prevalence of intestinal nematode parasitism among pet dogs in the United States and characterize risk factors for infection. Retrospective period prevalence survey. 1,213,061 dogs examined at 547 private veterinary hospitals in 44 states from January 1, 2003, through December 31, 2006. Data were obtained from electronic medical records of all dogs that had at least 1 fecal flotation test. Risk factors for intestinal nematode parasitism were identified by means of multivariable logistic regression analysis. 2,785,248 fecal flotation tests were performed during the study period. When results for only the first test in each dog were considered, prevalences of Toxocara, Ancylostoma, and Trichuris parasitism were 5.04%, 4.50%, and 0.81%, respectively. Dogs parasitism, compared with dogs > 5.0 years old; sexually intact male and female dogs had higher odds of parasitism, compared with spayed female dogs; toy dogs had lower odds of parasitism, compared with dogs in other breed groups; and dogs living in the mountain region had lower odds of parasitism, compared with dogs living in other regions. Results suggested that age, body weight, sex, breed, and geographic region were risk factors for intestinal nematode parasitism among pet dogs in the United States.

  12. Binding of hematin by a nem class of glutathione transferase from the blood-feeding parasitic nematode Haemonchus contortus

    NARCIS (Netherlands)

    Rossum, A.J.; Jefferies, J.R.; Rijsewijk, F.A.M.; LaCourse, E.J.; Teesdale, P.; Barrett, J.; Tait, A.; Brophy, P.M.

    2004-01-01

    The phase II detoxification system glutathione transferase (GST) is associated with the establishment of parasitic nematode infections within the gastrointestinal environment of the mammalian host. We report the functional analysis of a GST from an important worldwide parasitic nematode of small

  13. A check-list of the nematode parasites of South African Serpentes (snakes) and Sauria (lizards).

    Science.gov (United States)

    Hering-Hagenbeck, S F; Boomker, J

    2000-03-01

    Published records, in combination with own data have been brought together to provide data on parasite/host relationships of reptiles that occur in the Republic of South Africa. A total of 62 nematode species belonging to 23 genera and 11 families are recorded from 20 snake and 21 lizard species. The genera Kalicephalus, Spauligodon, Ophidascaris and Abbreviata are especially well represented with between five and eight species per genus. The most nematode species were recorded from the flap-neck chameleon, Chamaeleo dilepis (eight), the puff-adder, Bitis arietans (eight) and the water monitor, Varanus niloticus (seven). All synonyms of parasites and hosts are given.

  14. Nematode parasite diversity in birds: the role of host ecology, life history and migration.

    Science.gov (United States)

    Leung, Tommy L F; Koprivnikar, Janet

    2016-11-01

    Previous studies have found that migratory birds generally have a more diverse array of pathogens such as parasites, as well as higher intensities of infection. However, it is not clear whether this is driven by the metabolic and physiological demands of migration, differential selection on host life-history traits or basic ecological differences between migratory and non-migratory species. Parasitic helminths can cause significant pathology in their hosts, and many are trophically transmitted such that host diet and habitat use play key roles in the acquisition of infections. Given the concurrent changes in avian habitats and migratory behaviour, it is critical to understand the degree to which host ecology influences their parasite communities. We examined nematode parasite diversity in 153 species of Anseriformes (water birds) and Accipitriformes (predatory birds) in relation to their migratory behaviour, diet, habitat use, geographic distribution and life history using previously published data. Overall, migrators, host species with wide geographic distributions and those utilizing multiple aquatic habitats had greater nematode richness (number of species), and birds with large clutches harboured more diverse nematode fauna with respect to number of superfamilies. Separate analyses for each host order found similar results related to distribution, habitat use and migration; however, herbivorous water birds played host to a less diverse nematode community compared to those that consume some animals. Birds using multiple aquatic habitats have a more diverse nematode fauna relative to primarily terrestrial species, likely because there is greater opportunity for contact with parasite infectious stages and/or consumption of infected hosts. As such, omnivorous and carnivorous birds using aquatic habitats may be more affected by environmental changes that alter their diet and range. Even though there were no overall differences in their ecology and life history

  15. Nematode parasites of the channids in Orogodo River, Southern ...

    African Journals Online (AJOL)

    ... showed the water to be stressed with high BOD and nutrients levels. The intensity of the parasites in the host fish agree with previous hypotheses suggesting that environmental pollution does affect parasite population. Keywords: Parachanna obscura, Parachanna africana, biomonitoring, parasite intensity, Orogodo River

  16. The gastropod shell has been co-opted to kill parasitic nematodes.

    Science.gov (United States)

    Rae, R

    2017-07-06

    Exoskeletons have evolved 18 times independently over 550 MYA and are essential for the success of the Gastropoda. The gastropod shell shows a vast array of different sizes, shapes and structures, and is made of conchiolin and calcium carbonate, which provides protection from predators and extreme environmental conditions. Here, I report that the gastropod shell has another function and has been co-opted as a defense system to encase and kill parasitic nematodes. Upon infection, cells on the inner layer of the shell adhere to the nematode cuticle, swarm over its body and fuse it to the inside of the shell. Shells of wild Cepaea nemoralis, C. hortensis and Cornu aspersum from around the U.K. are heavily infected with several nematode species including Caenorhabditis elegans. By examining conchology collections I show that nematodes are permanently fixed in shells for hundreds of years and that nematode encapsulation is a pleisomorphic trait, prevalent in both the achatinoid and non-achatinoid clades of the Stylommatophora (and slugs and shelled slugs), which diverged 90-130 MYA. Taken together, these results show that the shell also evolved to kill parasitic nematodes and this is the only example of an exoskeleton that has been co-opted as an immune system.

  17. Recent Duplication and Functional Divergence in Parasitic Nematode Levamisole-Sensitive Acetylcholine Receptors.

    Directory of Open Access Journals (Sweden)

    Thomas B Duguet

    2016-07-01

    Full Text Available Helminth parasites rely on fast-synaptic transmission in their neuromusculature to experience the outside world and respond to it. Acetylcholine plays a pivotal role in this and its receptors are targeted by a wide variety of both natural and synthetic compounds used in human health and for the control of parasitic disease. The model, Caenorhabditis elegans is characterized by a large number of acetylcholine receptor subunit genes, a feature shared across the nematodes. This dynamic family is characterized by both gene duplication and loss between species. The pentameric levamisole-sensitive acetylcholine receptor has been characterized from C. elegans, comprised of five different subunits. More recently, cognate receptors have been reconstituted from multiple parasitic nematodes that are found to vary in subunit composition. In order to understand the implications of receptor composition change and the origins of potentially novel drug targets, we investigated a specific example of subunit duplication based on analysis of genome data for 25 species from the 50 helminth genome initiative. We found multiple independent duplications of the unc-29, acetylcholine receptor subunit, where codon substitution rate analysis identified positive, directional selection acting on amino acid positions associated with subunit assembly. Characterization of four gene copies from a model parasitic nematode, Haemonchus contortus, demonstrated that each copy has acquired unique functional characteristics based on phenotype rescue of transgenic C. elegans and electrophysiology of receptors reconstituted in Xenopus oocytes. We found evidence that a specific incompatibility has evolved for two subunits co-expressed in muscle. We demonstrated that functional divergence of acetylcholine receptors, driven by directional selection, can occur more rapidly than previously thought and may be mediated by alteration of receptor assembly. This phenomenon is common among the

  18. Haemonchus contortus and Trichostrongylus colubriformis did not adapt to long-term exposure to sheep that were genetically resistant or susceptible to nematode infections.

    Science.gov (United States)

    Kemper, K E; Elwin, R L; Bishop, S C; Goddard, M E; Woolaston, R R

    2009-04-01

    We tested the hypothesis that Haemonchus contortus and Trichostrongylus colubriformis would adapt to long-term exposure to sheep that were either genetically resistant or susceptible to H. contortus. Sheep genotypes were from lines with 10 years prior selection for low (resistant, R) or high (susceptible, S) faecal worm egg count (WEC) following H. contortus infection. Long-term exposure of H. contortus and T.colubriformis to R or S genotypes was achieved using serial passage for up to 30 nematode generations. Thus, we generated four nematode strains; one strain of each species solely exposed to R sheep and one strain of each species solely exposed to S sheep. Considerable host genotype differences in mean WEC during serial passage confirmed adequate nematode selection pressure for both H. contortus (R 4900 eggs per gram (epg), S 19,900 epg) and T. colubriformis (R 5300 epg, S 13,500 epg). Adaptation of nematode strain to host genotype was tested using seven cross-classified tests for H. contortus, and two cross-classified and one outbred genotype test for T. colubriformis. In the cross-classified design, where each strain infects groups of R, S or randomly bred control sheep, parasite adaptation would be indicated by a significant host genotype by nematode strain interaction for traits indicating parasite reproductive success; specifically WEC and, for H. contortus strains, packed cell volume. We found no significant evidence of parasite adaptation to host genotype (P>0.05) for either the H. contortus or T. colubriformis strains. Therefore, we argue that nematodes will not adapt quickly to sheep bred for nematode resistance, where selection is based on low WEC, although selecting sheep using a subset of immune functions may increase adaptation risk. Our results support the hypothesis that nematode resistance is determined by many genes each with relatively small effect. In conclusion, selection of sheep for nematode resistance using WEC should be sustainable in

  19. Hybrid fitness in a locally adapted parasite.

    Science.gov (United States)

    Dybdahl, Mark F; Jokela, Jukka; Delph, Lynda F; Koskella, Britt; Lively, Curtis M

    2008-12-01

    The parasite (Red Queen) hypothesis for the maintenance of sexual reproduction and genetic diversity assumes that host-parasite interactions result from tight genetic specificity. Hence, hybridization between divergent parasite populations would be expected to disrupt adaptive gene combinations, leading to reduced infectivity on exposure to parental sympatric hosts, as long as gene effects are nonadditive. In contrast, hybridization would not cause reduced infectivity on allopatric hosts unless the divergent parasite populations possess alleles that are intrinsically incompatible when they are combined. In three different experiments, we compared the infectivity of locally adapted parasite (trematode) populations with that of F(1) hybrid parasites when exposed to host (snail) populations that were sympatric to one of the two parasite populations. We tested for intrinsic genetic incompatibilities in two experiments by including one host population that was allopatric to both parasite populations. As predicted, when the target host populations were sympatric to the parasite populations, the hybrids were significantly less infective than the parental average, while hybrid parasites on allopatric hosts were not, thereby ruling out intrinsic genetic incompatibilities. The results are consistent with nonadditive gene effects and tightly specific host-driven selection underlying parasite divergence, as envisioned by coevolutionary theory and the Red Queen hypothesis.

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

    Czech Academy of Sciences Publication Activity Database

    Moravec, František

    2007-01-01

    Roč. 49, č. 3 (2007), s. 155-160 ISSN 0048-2951 R&D Projects: GA ČR(CZ) GA524/06/0170; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : parasitic nematode * research * fish Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine

  1. Plant-parasitic nematodes associated with olive trees in Al-Jouf region, north Saudi Arabia

    Science.gov (United States)

    A preliminary survey of plant-parasitic nematodes associated with olive was performed in Al-Jouf region, north Saudi Arabia. Olive is a newly introduced crop in this region, and is cultivated in the agricultural enterprises of some of the biggest Saudi agricultural companies. Seedlings are mostly im...

  2. On the modulation of innate immunity by plant-parasitic cyst nematodes

    NARCIS (Netherlands)

    Postma, W.J.

    2013-01-01

    Plant-parasitic cyst nematodes are major agricultural pests worldwide. These obligate endoparasites invade the roots of host plants where they transform cells near the vascular cylinder into a permanent feeding site. Plants possess a multilayered innate immune system consisting of different

  3. A survey of plant-parasitic nematodes of yam farms in Awka-North ...

    African Journals Online (AJOL)

    SARAH

    2015-11-30

    Nov 30, 2015 ... Duru et al. J. Appl. Biosci. 2015 A survey of plant-parasitic nematodes of yam farms in Awka-North local government area, Anambra state, Nigeria. 8951. INTRODUCTION. Yam (Dioscorea spp.) is an annual or perennial tuber-bearing and climbing plant that grows for 6-. 12 months depending on the cultivar ...

  4. GESTION DES NEMATODES A GALLES PARASITES DE LA ...

    African Journals Online (AJOL)

    ACSS

    Galeano, M. 2003. Evaluating Pochonia chlamydosporia in a double-cropping system of lettuce and tomato in plastic houses infested with Meloidogyne javanica. Plant Pathology 52: 521-528. Westerdahl, B.B. et Becker, J.O. 2009. Cucurbit Nematodes. UC Pest Management. Guidelines: Cucurbits. UC ANR Publication.

  5. PLANT-PARASITIC NEMATODES ON STONE FRUITS AND CITRUS IN LEBANON

    International Nuclear Information System (INIS)

    Ibrahim, S.K.; Azar, I.; Naser, CH.; Akikki, B; Ibrahim, L.

    2016-01-01

    This study aimed to determine the occurrence, distribution of plant parasitic nematodes on stone fruits in Lebanon and to determine the effect of plant extracts on the mortality of several nematode species. A total of 308 soil samples were collected from five different crops. Almost all surveyed areas showed infection with nematodes.The soil infestation rate with nematodes in collected soil samples from all 10 surveyed crops ranged from 66.6 to 100%. Eighteen out of 308 soil samples were free of nematodes (5.8%). All the collected soil samples from nectarine and plum orchards were infested with nematodes (100%), followed by citrus (97.6%), apple (88.7%), pear and quince (85.7%), and cherry (81.4%). The lowest infection (66.6%) was detected on almond and apricot. The level of infestation varied from one area to another and ranged between 0.1and 28 nematodes per 1 g of soil, with the highest number obtained on cherry. Several genera were identified based on morphological characters including:root-knot nematodes (Meloidogynespp.), Tylenchulus, Xiphinema, Rotylenchus, Pratylenchus, and Longidorus. Tylenchulus and Radopholus spp. were the most common on citrus trees, whereas Pratylechus and Meloidogyne spp. were detected almost in all the samples collected from all the crops. Six chopped aromatic plants were tested in pot experiments to control nematodes population densities. The results revealed that carbofuran (nematicide) was the most effective (88.48%) in comparison to the plant materials. Allium sativum gave the highest control (76.52%) followed by Tageta patula (72.0%), Cucurbita maxima (71.84%) and Inula viscosa (63.96%). Origanum syriacum (55.04%)d Thymus (53.72%) were less effective in comparison to the rest of tested plant materials. (author)

  6. Transmission electron microscopic observation of body cuticle structures of phoretic and parasitic stages of Parasitaphelenchinae nematodes.

    Directory of Open Access Journals (Sweden)

    Taisuke Ekino

    Full Text Available Using transmission electron microscopy, we examined the body cuticle ultrastructures of phoretic and parasitic stages of the parasitaphelenchid nematodes Bursaphelenchus xylophilus, B. conicaudatus, B. luxuriosae, B. rainulfi; an unidentified Bursaphelenchus species, and an unidentified Parasitaphelenchus species. Nematode body cuticles usually consist of three zones, a cortical zone, a median zone, and a basal zone. The phoretic stages of Bursaphelenchus spp., isolated from the tracheal systems of longhorn beetles or the elytra of bark beetles, have a thick and radially striated basal zone. In contrast, the parasitic stage of Parasitaphelenchus sp., isolated from bark beetle hemocoel, has no radial striations in the basal zone. This difference probably reflects the peculiar ecological characteristics of the phoretic stage. A well-developed basal radially striated zone, composed of very closely linked proteins, is the zone closest to the body wall muscle. Therefore, the striation is necessary for the phoretic species to be able to seek, enter, and depart from host/carrier insects, but is not essential for internal parasites in parasitaphelenchid nematodes. Phylogenetic relationships inferred from near-full-length small subunit ribosomal RNA sequences suggest that the cuticle structures of parasitic species have apomorphic characters, e.g., lack of striation in the basal zone, concurrent with the evolution of insect parasitism from a phoretic life history.

  7. IMMUNE REGULATING ES-PRODUCTS IN PARASITIC NEMATODES

    DEFF Research Database (Denmark)

    Bahlool, Qusay Zuhair Mohammad; Buchmann, Kurt; Kania, Per Walter

    work elucidates the effect of ES substances on the fish immune system by measuring immune gene expression in spleen and liver of rainbow trout (Oncorhynchus mykiss) injected intraperitoneally with ES products isolated from A. simplex third stage larvae. The overall gene expression profile of exposed...... fish showed a generalized down-regulation of the immune genes tested, suggesting a role of ES proteins in minimizing the immune reaction of rainbow trout against invading nematodes. We also tested the enzymatic activity of the ES proteins and found that lipase, esterase lipase, valine and cysteine...... arylamidases, naphthol-AS-BI-phosphohydrolase and a-galactosidase activities were present in the ES solution. This type of hydrolytic enzyme activity may play a role in nematode penetration of host tissue. Based on the notion that A. simplex ES-proteins may have an immune-depressive effect, it could also...

  8. Evaluation of Clonostachys rosea for Control of Plant-Parasitic Nematodes in Soil and in Roots of Carrot and Wheat.

    Science.gov (United States)

    Iqbal, Mudassir; Dubey, Mukesh; McEwan, Kerstin; Menzel, Uwe; Franko, Mikael Andersson; Viketoft, Maria; Jensen, Dan Funck; Karlsson, Magnus

    2018-01-01

    Biological control is a promising approach to reduce plant diseases caused by nematodes. We tested the effect of the fungus Clonostachys rosea strain IK726 inoculation on nematode community composition in a naturally nematode infested soil in a pot experiment, and the effect of C. rosea on plant health. The numbers of plant-parasitic nematode genera extracted from soil and plant roots decreased by 40 to 73% when C. rosea was applied, while genera of nonparasitic nematodes were not affected. Soil inoculation of C. rosea increased fresh shoot weight and shoot length of wheat plants by 20 and 24%, respectively, while only shoot dry weight increased by 48% in carrots. Light microscopy of in vitro C. rosea-nematode interactions did not reveal evidence of direct parasitism. However, culture filtrates of C. rosea growing in potato dextrose broth, malt extract broth and synthetic nutrient broth exhibited toxicity toward nematodes and immobilized 57, 62, and 100% of the nematodes, respectively, within 48 h. This study demonstrates that C. rosea can control plant-parasitic nematodes and thereby improve plant growth. The most likely mechanism responsible for the antagonism is antibiosis through production of nematicidal compounds, rather than direct parasitism.

  9. Parasitic nematode communities of the red kangaroo, Macropus rufus: richness and structuring in captive systems.

    Science.gov (United States)

    Lott, M J; Hose, G C; Power, M L

    2015-08-01

    Captive management practices have the potential to drastically alter pre-existing host-parasite relationships. This can have profound implications for the health and productivity of threatened species in captivity, even in the absence of clinical symptoms of disease. Maximising the success of captive breeding programmes requires a detailed knowledge of anthropogenic influences on the structure of parasite assemblages in captive systems. In this study, we employed two high-throughput molecular techniques to characterise the parasitic nematode (suborder Strongylida) communities of the red kangaroo, Macropus rufus, across seven captive sites. The first was terminal restriction fragment length polymorphism (T-RFLP) analysis of a region of rDNA encompassing the internal transcribed spacers 1 (ITS1), the 5.8S rRNA gene and the internal transcribed spacer 2 (ITS2). The second was Illumina MiSeq next-generation sequencing of the ITS2 region. The prevalence, intensity of infection, taxonomic composition and comparative structure of strongylid nematode assemblages was assessed at each location. Prevalence (P = <0.001) and mean infection intensity (df = 6, F = 17.494, P = <0.001) differed significantly between the seven captive sites. Significant levels of parasite community structure were observed (ANOSIM, P = 0.01), with most of the variation being distributed within, rather than between, captive sites. The range of nematode taxa that occurred in captive red kangaroos appeared to differ from that of wild conspecifics, with representatives of the genus Cloacina, a dominant nematode parasite of the macropodid forestomach, being detected at only two of the seven study sites. This study also provides the first evidence for the presence of the genus Trichostrongylus in a macropodid marsupial. Our results demonstrate that contemporary species management practices may exert a profound influence on the structure of parasite communities in captive systems.

  10. Factors associated with the suppressiveness of sugarcane soils to plant-parasitic nematodes

    Science.gov (United States)

    Stirling, Graham R.; Rames, Emily; Stirling, A. Marcelle; Hamill, Sharon

    2011-01-01

    Observations in three Australian sugarcane fields suggested that the soil just under the trash blanket (the covering of crop residue that remains on the soil surface after crops are harvested) was suppressive to plant-parasitic nematodes. Roots were concentrated in this upper layer of soil but plant-parasitic nematode populations were relatively low and roots showed few signs of nematode damage. Root biomass was much lower 15 cm further down the soil profile, where root health was poor and populations of plant-parasitic nematodes were 3-5 times higher than near the soil surface. A bioassay in which Radopholus similis (a nematode that does not occur in sugarcane soils) was inoculated into heat-sterilized and untreated soils, confirmed that biological factors were limiting nematode populations in some of the soils, with soil from 0-2 cm much more suppressive than soil from 15-17 cm. Surface soil from one site was highly suppressive, as only 16% of R. similis recoverable from heated soil were retrieved from this soil after 8 days. Numerous soil chemical, biochemical, and biological properties were measured, and non-linear regression analysis identified two major groups of factors that were significantly associated with suppressiveness. One group reflected the amount of organic matter in soil (total C, total N, and labile C) and the other was associated with the size of the free-living nematode community (total numbers of free-living nematodes, and numbers of plant associates, bacterial feeders, fungal feeders, and carnivores). These results suggested that suppressiveness was biologically mediated and was sustained by C inputs from crop residues and roots. Since nematode-trapping fungi in the test soils could not be quantified using traditional dilution plating methods, their possible role as suppressive agents was assessed by generating TRFLP profiles with Orbiliales-specific primers, and by sequencing cloned PCR products. Although the molecular data were obtained

  11. Prevalence and Molecular Identification of Nematode and Dipteran Parasites in an Australian Alpine Grasshopper (Kosciuscola tristis)

    Science.gov (United States)

    Umbers, Kate D. L.; Byatt, Lachlan J.; Hill, Nichola J.; Bartolini, Remo J.; Hose, Grant C.; Herberstein, Marie E.; Power, Michelle L

    2015-01-01

    In alpine Australia, Orthoptera are abundant, dominant herbivores, important prey species, and hosts for parasites and parasitoids. Despite the central role of orthopterans in alpine ecosystems, the impact of parasites on orthopteran populations is under-explored. In this study we describe the relationship between parasite prevalence and host sex, body size and year of collection. We accessed an existing, preserved collection of 640 Kosciuscola tristis collected from across its range between 2007 and 2011. Upon dissection we collected juvenile parasites and used molecular tools to identify them to three families (Nematoda; Mermithidae, and Arthropoda: Diptera: Tachinidae and Sarcophagidae). The prevalence of nematodes ranged from 3.5% to 25.0% and dipterans from 2.4% to 20.0%. Contrary to predictions, we found no associations between parasite prevalence and grasshopper sex or size. Although there was an association between prevalence of both nematodes and dipterans with year of collection, this is likely driven by a small sample size in the first year. Our results provide a foundation for future studies into parasite prevalence within the alpine environment and the abiotic factors that might influence these associations. PMID:25919745

  12. Plant systemic induced responses mediate interactions between root parasitic nematodes and aboveground herbivorous insects

    Directory of Open Access Journals (Sweden)

    Mesfin eWondafrash

    2013-04-01

    Full Text Available Insects and nematodes are the most diverse and abundant groups of multicellular animals feeding on plants on either side of the soil-air interface. Several herbivore-induced responses are systemic, and hence can influence the preference and performance of organisms in other plant organs. Recent studies show that plants mediate interactions between belowground plant parasitic nematodes and aboveground herbivorous insects. Based on the knowledge of plant responses to pathogens, we review the emerging insights on plant systemic responses against root-feeding nematodes and shoot-feeding insects. We discuss the potential mechanisms of plant-mediated indirect interactions between both groups of organisms and point to gaps in our knowledge. Root-feeding nematodes can positively or negatively affect shoot herbivorous insects, and vice versa. The outcomes of the interactions between these spatially separated herbivore communities appear to be influenced by the feeding strategy of the nematodes and the insects, as well as by host plant susceptibility to both herbivores. The potential mechanisms for these interactions include systemic induced plant defence, interference with the translocation and dynamics of locally induced secondary metabolites, and reallocation of plant nutritional reserves. During evolution, plant parasitic nematodes as well as herbivorous insects have acquired effectors that modify plant defence responses and resource allocation patterns to their advantage. However, it is also known that plants under herbivore attack change the allocation of their resources, e.g. for compensatory growth responses, which may affect the performance of other organisms feeding on the plant. Studying the chemical and molecular basis of these interactions will reveal the molecular mechanisms that are involved. Moreover, it will lead to a better understanding of the ecological relevance of aboveground-belowground interactions, as well as support the

  13. The transcriptome of the invasive eel swimbladder nematode parasite Anguillicola crassus.

    Science.gov (United States)

    Heitlinger, Emanuel; Bridgett, Stephen; Montazam, Anna; Taraschewski, Horst; Blaxter, Mark

    2013-02-08

    Anguillicola crassus is an economically and ecologically important parasitic nematode of eels. The native range of A. crassus is in East Asia, where it infects Anguilla japonica, the Japanese eel. A. crassus was introduced into European eels, Anguilla anguilla, 30 years ago. The parasite is more pathogenic in its new host than in its native one, and is thought to threaten the endangered An. anguilla across its range. The molecular bases for the increased pathogenicity of the nematodes in their new hosts is not known. A reference transcriptome was assembled for A. crassus from Roche 454 pyrosequencing data. Raw reads (756,363 total) from nematodes from An. japonica and An. anguilla hosts were filtered for likely host contaminants and ribosomal RNAs. The remaining 353,055 reads were assembled into 11,372 contigs of a high confidence assembly (spanning 6.6 Mb) and an additional 21,153 singletons and contigs of a lower confidence assembly (spanning an additional 6.2 Mb). Roughly 55% of the high confidence assembly contigs were annotated with domain- or protein sequence similarity derived functional information. Sequences conserved only in nematodes, or unique to A. crassus were more likely to have secretory signal peptides. Thousands of high quality single nucleotide polymorphisms were identified, and coding polymorphism was correlated with differential expression between individual nematodes. Transcripts identified as being under positive selection were enriched in peptidases. Enzymes involved in energy metabolism were enriched in the set of genes differentially expressed between European and Asian A. crassus. The reference transcriptome of A. crassus is of high quality, and will serve as a basis for future work on the invasion biology of this important parasite. The polymorphisms identified will provide a key tool set for analysis of population structure and identification of genes likely to be involved in increased pathogenicity in European eel hosts. The

  14. Inequalities in body size among mermithid nematodes parasitizing earwigs.

    Science.gov (United States)

    Maure, Fanny; Poulin, Robert

    2016-12-01

    Variation among body sizes of adult parasitic worms determines the relative genetic contribution of individuals to the next generation as it affects the effective parasite population size. Here, we investigate inequalities in body size and how they are affected by intensity of infection in Mermis nigrescens (Mermithidae: Nematoda) parasitizing the European earwig Forficula auricularia in New Zealand. Among a population of pre-adult worms prior to their emergence from the host, we observed only modest inequalities in body length; however, among worms sharing the same individual host, inequalities in body sizes decreased with increasing intensity of infection. Thus, the more worms occurred in a host, the more the second-longest, third-longest and even fourth-longest worms approached the longest worm in body length. This pattern, also known from another mermithid species, suggests that worms sharing the same host may have infected it roughly simultaneously, when the host encountered a clump of eggs in the environment. Thus, the life history and mode of infection of the parasite may explain the modest inequalities in the sizes achieved by pre-adult worms, which are lower than those reported for endoparasitic helminths of vertebrates.

  15. Management of pest mole crickets in Florida and Puerto Rico with a nematode and parasitic wasp

    International Nuclear Information System (INIS)

    Leppla, N.C.; Frank, J.H.; Adjei, M.B.; Vicente, N.E.

    2007-01-01

    Non-indigenous invasive mole crickets, Scapteriscus vicinus Scudder (Orthoptera: Gryllotalpidae) in Florida and S. didactylus (Latreille) (the 'changa') in Puerto Rico, are being managed with an entomopathogenic nematode, Steinernema scapterisci (Nguyen and Smart) (Rhabditida: Steinernematidae), and a parasitic wasp, Larra bicolor L. (Hymenoptera: Sphecidae). Pest mole cricket populations have declined by 95% in north central Florida since these specialist natural enemies were released and established in the 1980s. Commercial production of the nematode was initiated, nearly 70 billion were applied in 34 Florida counties, and their establishment, spread, and impact on mole crickets were monitored. The infected mole crickets dispersed the nematode rapidly, so that within 6 months these parasites were present in most of the insects trapped in experimental pastures. Three years later, mole cricket populations were reduced to acceptable levels and the bahiagrass had recovered. The nematode was released for the first time in Puerto Rico during 2001 and has persisted; the wasp was introduced in the late 1930s. The geographical distribution of the wasp is being expanded in Florida and Puerto Rico by planting plots of Spermacoce verticillata (L.), a wildflower indigenous to Puerto Rico and widely distributed in southern Florida. Pastures, sod farms, golf courses, landscapes, and vegetable farms in Florida and Puerto Rico are benefiting from biological control of invasive mole crickets. (author) [es

  16. Insights into Adaptations to a Near-Obligate Nematode Endoparasitic Lifestyle from the Finished Genome of Drechmeria coniospora

    NARCIS (Netherlands)

    Zhang, L.; Zhou, Z.; Guo, Q.; Fokkens, L.; Miskei, M.; Pócsi, I.; Zhang, W.; Chen, M.; Wang, L.; Sun, Y.; Donzelli, B.G.G.; Gibson, D.M.; Nelson, D.R.; Luo, J.G.; Rep, M.; Liu, H.; Yang, S.; Wang, J.; Krasnoff, S.B.; Xu, Y.; Molnár, I.; Lin, M.

    2016-01-01

    Nematophagous fungi employ three distinct predatory strategies: nematode trapping, parasitism of females and eggs, and endoparasitism. While endoparasites play key roles in controlling nematode populations in nature, their application for integrated pest management is hindered by the limited

  17. Reproduction of Plant-parasitic Nematodes on Winter Rapeseed (Brassica napus ssp. oleiferas)

    OpenAIRE

    Bernard, E. C.; Montgomery-Dee, M. E.

    1993-01-01

    The reproduction of isolates of five plant-parasitic nematode species on the winter rapeseed cultivars Bridger, Gorzanski, H-47, Lindora, and Viking was evaluated. Each cultivar was a good host for Helicotylenchus pseudorobustus, Meloidogyne hapla, and M. incognita, All rapeseed cultivars were poor hosts for Pratylenchus scribneri, in comparison with a susceptible reference host. Heterodera glycines females rarely developed on any cultivar, but low numbers of juveniles invaded roots and males...

  18. Nematode parasites of Clarias gariepinus (Burchell, 1822) from the Rietvlei Dam, South Africa.

    Science.gov (United States)

    Barson, M; Avenant-Oldewage, A

    2006-06-01

    Catfish, Clarias gariepinus, from the Rietvlei Dam near Pretoria, South Africa were examined for nematode parasites. Two species, Procamallanus laeviconchus in the stomach and Contracaecum spp. larvae in the abdominal cavity, were found. The morphology of these species, based on light and scanning electron microscopy, and how they compare with previously described specimens are discussed. Infection rates were mild compared to previous surveys although Contracaecum spp. had a high prevalence of 86%.

  19. Lack of evidence for co-speciation in a parasitic nematode of grey kangaroos.

    Science.gov (United States)

    Chilton, N B; Morris, G M; Beveridge, I; Coulson, G

    2004-09-01

    Multilocus enzyme electrophoresis was used to compare specimens of the parasitic nematode Cloacina obtusa from the stomach of the eastern grey kangaroo, Macropus giganteus and the western grey kangaroo, M. fuliginosus. Allelic variation among nematodes was detected at 17 (85%) of 20 loci, but there was only a single fixed genetic difference (at the locus for isocitrate dehydrogenase, IDH) between C. obtusa from M. fuliginosus and those from M. giganteus in areas where each host occurred in allopatry. However, this fixed difference was not apparent within the zone of host sympatry. Although electrophoretic data indicate genetic divergence among allopatric populations of C. obtusa in the two host species, the magnitude of the electrophoretic difference (5%) between these populations does not refute the hypothesis that C. obtusa represents a single species. The 'usual' situation for parasitic helminths of grey kangaroos is that pairs of parasite species occur in the two host species. This situation differs for C. obtusa, where there has been a lack of speciation following a speciation event in its macropodid marsupial hosts. This finding suggests that a speciation event in the host does not necessarily lead to a speciation event for all its parasites and further highlights our lack of understanding of which processes drive speciation in parasites.

  20. Anthelmintic effects of forage chicory against parasitic nematodes in cattle

    DEFF Research Database (Denmark)

    Pena-Espinoza, Miguel Angel; Williams, Andrew; Thamsborg, Stig Milan

    . ostertagi. L1 viability was evaluated after 12 hours incubation. RESULTS: Mean FECs (corrected for faecal dry matter) were not different between groups (p=0.14), but weight gains were higher in CHI calves (+ 35%; p... mg/mL). CONCLUSIONS: Based on these preliminary results, chicory silage (Spadona) has significant in vivo anthelmintic effects against O. ostertagi, possibly mediated by SL, and marked differences exist in the anti-parasitic activity of SL extracts from two different chicory cultivars....

  1. A phylogenetic test of the Red Queen Hypothesis: outcrossing and parasitism in the Nematode phylum.

    Science.gov (United States)

    Gibson, Amanda Kyle; Fuentes, Jesualdo Arturo

    2015-02-01

    Sexual outcrossing is costly relative to selfing and asexuality, yet it is ubiquitous in nature, a paradox that has long puzzled evolutionary biologists. The Red Queen Hypothesis argues that outcrossing is maintained by antagonistic interactions between host and parasites. Most tests of this hypothesis focus on the maintenance of outcrossing in hosts. The Red Queen makes an additional prediction that parasitic taxa are more likely to be outcrossing than their free-living relatives. We test this prediction in the diverse Nematode phylum using phylogenetic comparative methods to evaluate trait correlations. In support of the Red Queen, we demonstrate a significant correlation between parasitism and outcrossing in this clade. We find that this correlation is driven by animal parasites, for which outcrossing is significantly enriched relative to both free-living and plant parasitic taxa. Finally, we test hypotheses for the evolutionary history underlying the correlation of outcrossing and animal parasitism. Our results demonstrate that selfing and asexuality are significantly less likely to arise on parasitic lineages than on free-living ones. The findings of this study are consistent with the Red Queen Hypothesis. Moreover, they suggest that the maintenance of genetic variation is an important factor in the persistence of parasitic lineages. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  2. Population density and phenotypic attributes influence the level of nematode parasitism in roe deer.

    Science.gov (United States)

    Body, Guillaume; Ferté, Hubert; Gaillard, Jean-Michel; Delorme, Daniel; Klein, François; Gilot-Fromont, Emmanuelle

    2011-11-01

    The impact of parasites on population dynamics is well documented, but less is known on how host population density affects parasite spread. This relationship is difficult to assess because of confounding effects of social structure, population density, and environmental conditions that lead to biased among-population comparisons. Here, we analyzed the infestation by two groups of nematodes (gastro-intestinal (GI) strongyles and Trichuris) in the roe deer (Capreolus capreolus) population of Trois Fontaines (France) between 1997 and 2007. During this period, we experimentally manipulated population density through changes in removals. Using measures collected on 297 individuals, we quantified the impact of density on parasite spread after taking into account possible influences of date, age, sex, body mass, and weather conditions. The prevalence and abundance of eggs of both parasites in females were positively related to roe deer density, except Trichuris in adult females. We also found a negative relationship between parasitism and body mass, and strong age and sex-dependent patterns of parasitism. Prime-age adults were less often parasitized and had lower fecal egg counts than fawns or old individuals, and males were more heavily and more often infected than females. Trichuris parasites were not affected by weather, whereas GI strongyles were less present after dry and hot summers. In the range of observed densities, the observed effect of density likely involves a variation of the exposure rate, as opposed to variation in host susceptibility.

  3. Angiostrongylus cantonensis: An optimized cultivation of this parasitic nematode under laboratory conditions.

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    Xie, Hui; Yuan, Dongjuan; Luo, Shiqi; Zeng, Xingda; Zeng, Xin; He, Ping; Lv, Zhiyue; Wu, Zhongdao

    2017-08-01

    Angiostrongylus cantonensis (A. cantonensis), a parasitic nematode, is the important neurotropic pathogen which causes human angiostrongyliasis. It has a complex life-cycle and severe parasite-host interaction in contrast to free-living nematode. Establishment of a well-suited life-cycle and in vitro cultivation of A. cantonensis in the laboratory will be one of the key techniques to elucidate the mechanism of parasite-host interaction. However, the low survival and growth rate of worms is still to be the problem. We optimized the known life-cycle of A. cantonensis in the laboratory, showing that small in size, easy to breed, and high compatibility of Biomphalaria straminea precede the common snails as an intermediate host of A. cantonensis. Furthermore, the egg hatching rate in Ham's F-12 medium reached approximately 80% using the eggs of mature female adult worms. We also demonstrated that the survival of larvae could be sustained for more than 30 days by in vitro cultivation of L1 larvae in DMEM with mixed antibiotics (100 units/mL of penicillin G potassium, 50 μg/mL of streptomycin sulfate, and 0.5 μg/mL of amphotericin B) and L3, L4, and L5 larvae in Waymouth's medium with 20% fetal calf serum and mixed antibiotics. Infective L1 and L3 larvae kept high infective rate to the snail and rat after cultivation in these media, respectively. It will provide the basis for studying on genetic manipulations for functional genes, new drug screening, and the mechanism of parasite-host interaction of parasitic nematodes.

  4. Characterization of the Pratylenchus penetrans transcriptome including data mining of putative nematode genes involved in plant parasitism

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    The root lesion nematode Pratylenchus penetrans is considered one of the most economically important species within the genus. Host range studies have shown that nearly 400 plant species can be parasitized by this species. To obtain insight into the transcriptome of this migratory plant-parasitic ne...

  5. A pharmacological study of NLP-12 neuropeptide signaling in free-living and parasitic nematodes.

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    Peeters, Lise; Janssen, Tom; De Haes, Wouter; Beets, Isabel; Meelkop, Ellen; Grant, Warwick; Schoofs, Liliane

    2012-03-01

    NLP-12a and b have been identified as cholecystokinin/sulfakinin-like neuropeptides in the free-living nematode Caenorhabditis elegans. They are suggested to play an important role in the regulation of digestive enzyme secretion and fat storage. This study reports on the identification and characterization of an NLP-12-like peptide precursor gene in the rat parasitic nematode Strongyloides ratti. The S. ratti NLP-12 peptides are able to activate both C. elegans CKR-2 receptor isoforms in a dose-dependent way with affinities in the same nanomolar range as the native C. elegans NLP-12 peptides. The C-terminal RPLQFamide sequence motif of the NLP-12 peptides is perfectly conserved between free-living and parasitic nematodes. Based on systemic amino acid replacements the Arg-, Leu- and Phe- residues appear to be critical for high-affinity receptor binding. Finally, a SAR analysis revealed the essential pharmacophore in C. elegans NLP-12b to be the pentapeptide RPLQFamide. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Tv-RIO1 – an atypical protein kinase from the parasitic nematode Trichostrongylus vitrinus

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    Sternberg Paul W

    2008-09-01

    Full Text Available Abstract Background Protein kinases are key enzymes that regulate a wide range of cellular processes, including cell-cycle progression, transcription, DNA replication and metabolic functions. These enzymes catalyse the transfer of phosphates to serine, threonine and tyrosine residues, thus playing functional roles in reversible protein phosphorylation. There are two main groups, namely eukaryotic protein kinases (ePKs and atypical protein kinases (aPKs; RIO kinases belong to the latter group. While there is some information about RIO kinases and their roles in animals, nothing is known about them in parasites. This is the first study to characterise a RIO1 kinase from any parasite. Results A full-length cDNA (Tv-rio-1 encoding a RIO1 protein kinase (Tv-RIO1 was isolated from the economically important parasitic nematode Trichostrongylus vitrinus (Order Strongylida. The uninterrupted open reading frame (ORF of 1476 nucleotides encoded a protein of 491 amino acids, containing the characteristic RIO1 motif LVHADLSEYNTL. Tv-rio-1 was transcribed at the highest level in the third-stage larva (L3, and a higher level in adult females than in males. Comparison with homologues from other organisms showed that protein Tv-RIO1 had significant homology to related proteins from a range of metazoans and plants. Amino acid sequence identity was most pronounced in the ATP-binding motif, active site and metal binding loop. Phylogenetic analyses of selected amino acid sequence data revealed Tv-RIO1 to be most closely related to the proteins in the species of Caenorhabditis. A structural model of Tv-RIO1 was constructed and compared with the published crystal structure of RIO1 of Archaeoglobus fulgidus (Af-Rio1. Conclusion This study provides the first insights into the RIO1 protein kinases of nematodes, and a foundation for further investigations into the biochemical and functional roles of this molecule in biological processes in parasitic nematodes.

  7. Nematode parasite control of livestock in the tropics/subtropics: the need for novel approaches.

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    Waller, P J

    1997-10-01

    Because parasites are more abundant, small ruminants in the tropical/subtropical regions of the world experience much greater ravages from internal parasitic disease than those in the temperate regions. In the tropics/subtropics, the limiting ecological factor influencing the severity of parasitism is rainfall, as temperatures almost always favour hatching and development of the free-living stages. Attempts to expand sheep and goat production by replacing traditional village production systems, which rarely involve anthelmintic treatment, with large-scale intensive commercial enterprises invariably induce complete reliance on anthelmintics to control nematode parasites. This has led to the widespread development of high level, multiple anthelmintic resistance throughout the tropics/subtropics, and in certain regions this has reached the ultimate disastrous scenario of total chemotherapeutic failure. Immediate concerted efforts are needed to resolve this crisis. Significant benefits are likely to emerge from research into non-chemotherapeutic approaches to nematode parasite control, such as grazing management, worm vaccines, breed selection and biological control. However, it is likely that none, in isolation or collectively, will completely replace the need for effective anthelmintics. What is needed is the integration of all methods of parasite control as they come to hand, with the underlying aim of reducing the use and thus preserving the effectiveness of anthelmintics. Although cheap and simple procedures, based on sound epidemiological principles, can achieve dramatic benefits in worm control, they have been poorly adopted by livestock owners. Clearly then, the greatest need is for technology transfer and education programmes, but these activities are generally found to be chronically under-resourced.

  8. Experience-dependent olfactory behaviors of the parasitic nematode Heligmosomoides polygyrus.

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    Felicitas Ruiz

    2017-11-01

    Full Text Available Parasitic nematodes of humans and livestock cause extensive disease and economic loss worldwide. Many parasitic nematodes infect hosts as third-stage larvae, called iL3s. iL3s vary in their infection route: some infect by skin penetration, others by passive ingestion. Skin-penetrating iL3s actively search for hosts using host-emitted olfactory cues, but the extent to which passively ingested iL3s respond to olfactory cues was largely unknown. Here, we examined the olfactory behaviors of the passively ingested murine gastrointestinal parasite Heligmosomoides polygyrus. H. polygyrus iL3s were thought to reside primarily on mouse feces, and infect when mice consume feces containing iL3s. However, iL3s can also adhere to mouse fur and infect orally during grooming. Here, we show that H. polygyrus iL3s are highly active and show robust attraction to host feces. Despite their attraction to feces, many iL3s migrate off feces to engage in environmental navigation. In addition, H. polygyrus iL3s are attracted to mammalian skin odorants, suggesting that they migrate toward hosts. The olfactory preferences of H. polygyrus are flexible: some odorants are repulsive for iL3s maintained on feces but attractive for iL3s maintained off feces. Experience-dependent modulation of olfactory behavior occurs over the course of days and is mediated by environmental carbon dioxide (CO2 levels. Similar experience-dependent olfactory plasticity occurs in the passively ingested ruminant-parasitic nematode Haemonchus contortus, a major veterinary parasite. Our results suggest that passively ingested iL3s migrate off their original fecal source and actively navigate toward hosts or new host fecal sources using olfactory cues. Olfactory plasticity may be a mechanism that enables iL3s to switch from dispersal behavior to host-seeking behavior. Together, our results demonstrate that passively ingested nematodes do not remain inactive waiting to be swallowed, but rather display

  9. Nematodes (Mermithidae parasitizing grasshoppers (Orthoptera: Acrididae in the Pampean region, Argentina

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    J. M. Rusconi

    Full Text Available Abstract This work provides the results of a survey of entomonematodes parasites of grasshoppers in grasslands of the Pampean Region, Argentina. Nymphs of Staurorhectus longicornis Giglio-Tos, Laplatacris dispar Rhen, 1939, Dichroplus elongatus Giglio-Tos, 1894 and Metaleptea brevicornis (L. (Orthoptera: Acrididae were collected. Mermithidae was the only family registered with seven species: Agamermis decaudata Cobb, Steiner and Christie, 1923, Amphimermis bonaerensis Miralles and Camino, 1983, Amphimermis dichroplusi Camino and Lange, 1997, Amphimermis ronderosi Camino and Lange, 1997, Hexamermis coclhearius Stock and Camino, 1992, Hexamermis ovistriata Stock and Camino, 1992, and Longimermis acridophila Camino and Stock, 1989. The values of parasitism ranged between 1-12%, and intensity not overcome the number of 5.0 nematodes per larva. The nematodes observed showed specificity, not registering the same species of parasite in more than one host species. The Pampean region constituted an area with high diversity of mermithids where new species could be consider as bioregulator agents of this troublesome insect pests in agricultural areas of Argentina.

  10. Nematodes (Mermithidae) parasitizing grasshoppers (Orthoptera: Acrididae) in the Pampean region, Argentina.

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    Rusconi, J M; Camino, N B; Achinelly, M F

    2017-03-01

    This work provides the results of a survey of entomonematodes parasites of grasshoppers in grasslands of the Pampean Region, Argentina. Nymphs of Staurorhectus longicornis Giglio-Tos, Laplatacris dispar Rhen, 1939, Dichroplus elongatus Giglio-Tos, 1894 and Metaleptea brevicornis (L.) (Orthoptera: Acrididae) were collected. Mermithidae was the only family registered with seven species: Agamermis decaudata Cobb, Steiner and Christie, 1923, Amphimermis bonaerensis Miralles and Camino, 1983, Amphimermis dichroplusi Camino and Lange, 1997, Amphimermis ronderosi Camino and Lange, 1997, Hexamermis coclhearius Stock and Camino, 1992, Hexamermis ovistriata Stock and Camino, 1992, and Longimermis acridophila Camino and Stock, 1989. The values of parasitism ranged between 1-12%, and intensity not overcome the number of 5.0 nematodes per larva. The nematodes observed showed specificity, not registering the same species of parasite in more than one host species. The Pampean region constituted an area with high diversity of mermithids where new species could be consider as bioregulator agents of this troublesome insect pests in agricultural areas of Argentina.

  11. Structural and functional characterisation of FOXO/Acan-DAF-16 from the parasitic nematode Angiostrongylus cantonensis.

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    Yan, Baolong; Sun, Weiwei; Yan, Lanzhu; Zhang, Liangliang; Zheng, Yuan; Zeng, Yuzhen; Huang, Huicong; Liang, Shaohui

    2016-12-01

    Fork head box transcription factors subfamily O (FoxO) is regarded to be significant in cell-cycle control, cell differentiation, ageing, stress response, apoptosis, tumour formation and DNA damage repair. In the free-living nematode Caenorhabditis elegans, the FoxO transcription factor is encoded by Ce-daf-16, which is negatively regulated by insulin-like signaling (IIS) and involved in promoting dauer formation through bringing about its hundreds of downstream genes expression. In nematode parasites, orthologues of daf-16 from several species have been identified, with functions in rescue of dauer phenotypes determined in a surrogate system C. elegans. In this study, we identified the FoxO encoding gene, Acan-daf-16, from the parasitic nematode Angiostrongylus cantonensis, and determined the genomic structures, transcripts and functions far more thorough in longevity, stress resistance and dauer formation. Acan-daf-16 encodes two proteins, Acan-DAF-16A and Acan-DAF-16B, consisting of 555 and 491 amino acids, respectively. Both isoforms possess the highly conserved fork head domains. Acan-daf-16A and Acan-daf-16B are expressed from distinct promoters. The expression patterns of Acan-daf-16 isoforms in the C. elegans surrogate system showed that p Acan-daf-16a:gfp was expressed in all cells of C. elegans, including the pharynx, and the expression of p Acan-daf-16b:gfp was restricted to the pharynx. In addition to the same genomic organization to the orthologue in C. elegans, Ce-daf-16, both Acan-DAF-16 isoforms could restore the C. elegans daf-16(mg54) mutation in longevity, dauer formation and stress resistance, in spite of the partial complementation of Acan-DAF-16B isoform in longevity. These findings provide further evidence of the functional conservation of DAF-16s between parasitic nematodes and the free-living nematode C. elegans. Copyright © 2016. Published by Elsevier B.V.

  12. Some aspects of the taxonomy and biology of dracunculoid nematodes parasitic in fishes: a review.

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    Moravec, Frantisek

    2004-03-01

    The nematode superfamily Dracunculoidea includes 166 recognized species, of which 150 (90%) are parasitic in about 300 species of freshwater, brackish-water and marine fishes. Fish dracunculoids are placed in 31 genera (86% of all dracunculoid genera) belonging to eight of the nine dracunculoid families: Anguillicolidae, Daniconematidae, Guyanemidae, Lucionematidae, Micropleuridae, Philometridae, Skrjabillanidae, and Tetanonematidae; the genus Lockenloia is considered incertae sedis. Because of difficulties in studying fish dracunculoids, associated with their morphological and biological peculiarities, most species of these largely histozoic parasites are poorly known and males of the majority of species and of eight genera have not yet been discovered. It is apparent that the present classification system of dracunculoids as a whole does not reflect phylogenetic relationships and a taxonomic revision of this nematode group, based on detailed morphological (including SEM and TEM), life history and molecular studies of individual species, is quite necessary. Data on the biology of fish dracunculoids is scarce. In known cases, their life cycles involve copepods, ostracods or branchiurids as intermediate hosts and, sometimes, fish paratenic hosts are known to occur in dracunculoid species parasitizing as adults piscivorous definitive hosts. However, nothing is known about the life cycles of representatives of 20 genera. Some species of dracunculoids, particularly of philometrids, are highly pathogenic and are known as agents of serious fish diseases. During recent years, especially the importance of Philometra spp. parasitizing the gonads of many species of marine fishes has increased due in particular to the rapid development of marine aquaculture, because they may significantly decrease fish reproduction or even cause full parasitic castration. Therefore, further detailed studies on fish dracunculoids are significant not only from the theoretical viewpoint, but

  13. Anatomical Alterations in Plant Tissues Induced by Plant-Parasitic Nematodes

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    Juan E. Palomares-Rius

    2017-11-01

    Full Text Available Plant-parasitic nematodes (PPNs interact with plants in different ways, for example, through subtle feeding behavior, migrating destructively through infected tissues, or acting as virus-vectors for nepoviruses. They are all obligate biotrophic parasites as they derive their nutrients from living cells which they modify using pharyngeal gland secretions prior to food ingestion. Some of them can also shield themselves against plant defenses to sustain a relatively long lasting interaction while feeding. This paper is centered on cell types or organs that are newly induced in plants during PPN parasitism, including recent approaches to their study based on molecular biology combined with cell biology-histopathology. This issue has already been reviewed extensively for major PPNs (i.e., root-knot or cyst nematodes, but not for other genera (viz. Nacobbus aberrans, Rotylenchulus spp.. PPNs have evolved with plants and this co-evolution process has allowed the induction of new types of plant cells necessary for their parasitism. There are four basic types of feeding cells: (i non-hypertrophied nurse cells; (ii single giant cells; (iii syncytia; and (iv coenocytes. Variations in the structure of these cells within each group are also present between some genera depending on the nematode species viz. Meloidogyne or Rotylenchulus. This variability of feeding sites may be related in some way to PPN life style (migratory ectoparasites, sedentary ectoparasites, migratory ecto-endoparasites, migratory endoparasites, or sedentary endoparasites. Apart from their co-evolution with plants, the response of plant cells and roots are closely related to feeding behavior, the anatomy of the nematode (mainly stylet size, which could reach different types of cells in the plant, and the secretory fluids produced in the pharyngeal glands. These secretory fluids are injected through the stylet into perforated cells where they modify plant cytoplasm prior to food removal

  14. Anatomical Alterations in Plant Tissues Induced by Plant-Parasitic Nematodes

    Science.gov (United States)

    Palomares-Rius, Juan E.; Escobar, Carolina; Cabrera, Javier; Vovlas, Alessio; Castillo, Pablo

    2017-01-01

    Plant-parasitic nematodes (PPNs) interact with plants in different ways, for example, through subtle feeding behavior, migrating destructively through infected tissues, or acting as virus-vectors for nepoviruses. They are all obligate biotrophic parasites as they derive their nutrients from living cells which they modify using pharyngeal gland secretions prior to food ingestion. Some of them can also shield themselves against plant defenses to sustain a relatively long lasting interaction while feeding. This paper is centered on cell types or organs that are newly induced in plants during PPN parasitism, including recent approaches to their study based on molecular biology combined with cell biology-histopathology. This issue has already been reviewed extensively for major PPNs (i.e., root-knot or cyst nematodes), but not for other genera (viz. Nacobbus aberrans, Rotylenchulus spp.). PPNs have evolved with plants and this co-evolution process has allowed the induction of new types of plant cells necessary for their parasitism. There are four basic types of feeding cells: (i) non-hypertrophied nurse cells; (ii) single giant cells; (iii) syncytia; and (iv) coenocytes. Variations in the structure of these cells within each group are also present between some genera depending on the nematode species viz. Meloidogyne or Rotylenchulus. This variability of feeding sites may be related in some way to PPN life style (migratory ectoparasites, sedentary ectoparasites, migratory ecto-endoparasites, migratory endoparasites, or sedentary endoparasites). Apart from their co-evolution with plants, the response of plant cells and roots are closely related to feeding behavior, the anatomy of the nematode (mainly stylet size, which could reach different types of cells in the plant), and the secretory fluids produced in the pharyngeal glands. These secretory fluids are injected through the stylet into perforated cells where they modify plant cytoplasm prior to food removal. Some

  15. Comparative analysis of complete mitochondrial genome sequences confirms independent origins of plant-parasitic nematodes

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    Sultana Tahera

    2013-01-01

    Full Text Available Abstract Background The nematode infraorder Tylenchomorpha (Class Chromadorea includes plant parasites that are of agricultural and economic importance, as well as insect-associates and fungal feeding species. Among tylenchomorph plant parasites, members of the superfamily Tylenchoidea, such as root-knot nematodes, have great impact on agriculture. Of the five superfamilies within Tylenchomorpha, one (Aphelenchoidea includes mainly fungal-feeding species, but also some damaging plant pathogens, including certain Bursaphelenchus spp. The evolutionary relationships of tylenchoid and aphelenchoid nematodes have been disputed based on classical morphological features and molecular data. For example, similarities in the structure of the stomatostylet suggested a common evolutionary origin. In contrast, phylogenetic hypotheses based on nuclear SSU ribosomal DNA sequences have revealed paraphyly of Aphelenchoidea, with, for example, fungal-feeding Aphelenchus spp. within Tylenchomorpha, but Bursaphelenchus and Aphelenchoides spp. more closely related to infraorder Panagrolaimomorpha. We investigated phylogenetic relationships of plant-parasitic tylenchoid and aphelenchoid species in the context of other chromadorean nematodes based on comparative analysis of complete mitochondrial genome data, including two newly sequenced genomes from Bursaphelenchus xylophilus (Aphelenchoidea and Pratylenchus vulnus (Tylenchoidea. Results The complete mitochondrial genomes of B. xylophilus and P. vulnus are 14,778 bp and 21,656 bp, respectively, and identical to all other chromadorean nematode mtDNAs in that they contain 36 genes (lacking atp8 encoded in the same direction. Their mitochondrial protein-coding genes are biased toward use of amino acids encoded by T-rich codons, resulting in high A+T richness. Phylogenetic analyses of both nucleotide and amino acid sequence datasets using maximum likelihood and Bayesian methods did not support B. xylophilus as most

  16. Biogeography of Parasitic Nematode Communities in the Galápagos Giant Tortoise: Implications for Conservation Management.

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    Guillaume Fournié

    Full Text Available The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programmes. Coprological examinations revealed nematode eggs to be common, with more than 80% of tortoises infected within each wild population. Faecal samples from tortoises within captive breeding centres on Santa Cruz, Isabela and San Cristobal islands also were examined. Five different nematode egg types were identified: oxyuroid, ascarid, trichurid and two types of strongyle. Sequencing of the 18S small-subunit ribosomal RNA gene from adult nematodes passed with faeces identified novel sequences indicative of rhabditid and ascaridid species. In the wild, the composition of nematode communities varied according to tortoise species, which co-varied with island, but nematode diversity and abundance were reduced or altered in captive-reared animals. Evolutionary and ecological factors are likely responsible for the variation in nematode distributions in the wild. This possible species/island-parasite co-evolution has not been considered previously for Galápagos tortoises. We recommend that conservation efforts, such as the current Galápagos tortoise captive breeding/rearing and release programme, be managed with respect to parasite biogeography and host-parasite co-evolutionary processes in addition to the biogeography of the host.

  17. Biogeography of Parasitic Nematode Communities in the Galápagos Giant Tortoise: Implications for Conservation Management.

    Science.gov (United States)

    Fournié, Guillaume; Goodman, Simon J; Cruz, Marilyn; Cedeño, Virna; Vélez, Alberto; Patiño, Leandro; Millins, Caroline; Gibbons, Lynda M; Fox, Mark T; Cunningham, Andrew A

    2015-01-01

    The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programmes. Coprological examinations revealed nematode eggs to be common, with more than 80% of tortoises infected within each wild population. Faecal samples from tortoises within captive breeding centres on Santa Cruz, Isabela and San Cristobal islands also were examined. Five different nematode egg types were identified: oxyuroid, ascarid, trichurid and two types of strongyle. Sequencing of the 18S small-subunit ribosomal RNA gene from adult nematodes passed with faeces identified novel sequences indicative of rhabditid and ascaridid species. In the wild, the composition of nematode communities varied according to tortoise species, which co-varied with island, but nematode diversity and abundance were reduced or altered in captive-reared animals. Evolutionary and ecological factors are likely responsible for the variation in nematode distributions in the wild. This possible species/island-parasite co-evolution has not been considered previously for Galápagos tortoises. We recommend that conservation efforts, such as the current Galápagos tortoise captive breeding/rearing and release programme, be managed with respect to parasite biogeography and host-parasite co-evolutionary processes in addition to the biogeography of the host.

  18. Changes in the prevalence of parasitic nematode infections in dogs from animal asylums in Warsaw and sourroundings.

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    Górski, P; Szyja, A; Baska, P; Kazimierczak, K

    2009-01-01

    The distribution of parasitic nematodes of dogs from three shelters for homeless animals in the Warsaw region (Celestynów and Milanówek near Warsaw, Paluch in Warsaw) was investigated. It was found that since our previous investigations (1993-1995) the prevalence of nematode infections had increased in Celestynów and Milanówek and decreased in the municipal shelter in Warsaw (Paluch). The highest percentage of infected animals was found in Celestynów (as in 1993-1995). What can be the importance of local environmental conditions for the prevalence of nematode infections.

  19. Prevalence of common gastrointestinal nematode parasites in scavenging pigs of different ages and sexes in Eastern Centre province, Burkina Faso

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    H.H. Tamboura

    2006-09-01

    Full Text Available The range and infestation intensities of gastrointestinal parasitic nematode species depend on the type of swine production system. The present study focused mainly on nematodes of veterinary importance in scavenging pigs in Burkina Faso, and aimed at determining the prevalence of gastro-intestinal nematode parasites by means of faecal egg per gram (EPG counts. Between November 2001 and October 2002, faecal samples from 383 pigs of different sexes and ages ( 12 months were collected from the rectum and examined for gastrointestinal nematodes parasites using the Mc Master method. Of the 383 pigs examined, 91 % were infected by one or more para sites. Ascaris suum (40 %; 100-1 400 EPG was the most prevalent parasite followed by Strongyloides ransomi (21 %; 100-4 200 EPG, Oesophagostomum spp. (18 %; 100-1 000 EPG, Hyostrongylus rubidus (11 %; 100-1 800 EPG, Globocephalus spp. 10 %; 100-400 EPG and Trichuris suis (1 %; 100-200 EPG. The prevalence was significantly higher in female pigs (n = 239 than in males. In addition, females excreted significantly (P < 0.05 more eggs in their faeces than males, except in the case of Globocephalus spp. The age of the animal had no effect on the prevalence of A. suum whereas there were significant differences in age categories concerning S. ransomi, H. rubidus, Oesophagostumum spp. and Globocephalus spp. Unexpectedly, the high prevalence of these common parasites was not accompanied by elevated EPG values, which suggests the existence of moderate infestations. The present work indicates that the common nematode infestations in pigs do not necessarily need a systematic herd anthelmintic treatment, as only a small number of worms is required to induce immunity. A further study is needed to formulate appropriate and cost-effective strategies for the control of gastro-intestinal nematode parasites in pigs in Burkina Faso.

  20. Chemoattraction and host preference of the gastropod parasitic nematode Phasmarhabditis hermaphrodita.

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    Rae, Robbie G; Robertson, Jamie F; Wilson, Michael J

    2009-06-01

    Phasmarhabditis hermaphrodita is a parasitic nematode that has been formulated into a biological control agent for slugs. The nematode responds to slug-associated cues such as mucus and feces in order to locate potential hosts. We assessed the olfactory response of P. hermaphrodita to mucus from 9 species of slugs, 2 snails, and 2 earthworms (non-hosts). We then examined the susceptibility of each invertebrate test species to high doses of P. hermaphrodita to determine whether susceptible species are more attractive than non-susceptible species to the nematode. We also studied the numbers of infective juveniles produced in each test species, as well as infectivity. Phasmarhabditis hermaphrodita showed strong attraction to mucus from the non-susceptible slug Arion subfuscus, the snail Helix aspersa, and the highly susceptible slug Deroceras reticulatum. In reproduction experiments, P. hermaphrodita produced the highest number of infective juveniles in D. reticulatum and Deroceras panormitanum; however, there was no significant relationship with attraction. Phasmarhabditis hermaphrodita caused significant mortality in 5-11 gastropod species tested (and showed no chemotactic preference for susceptible or non-susceptible species). There was a significant positive relationship between numbers of P. hermaphrodita penetrating into non-susceptible species and chemotaxis response. These necromenic species represent ideal hosts for P. hermaphrodita in terms of providing protection against abiotic and biotic factors as well as transport to many diverse areas.

  1. Parasites of South African freshwater fish. VI. Nematode parasites of some fish species in the Kruger National Park.

    Science.gov (United States)

    Boomker, J

    1994-03-01

    The nematode parasites of 30 spot-tailed robbers, Brycinus imberi, five tiger-fish, Hydrocynus vittatus, 77 large-scaled yellowfish. Barbus marequensis, two mudsuckers, Labeo molybdinus, 114 catfish, Clarias gariepinus, 46 silver barbel, Schilbe intermedius, 66 squeakers, Synodontis zambezensis, three eels, Anguilla spp., 83 Mozambique bream, Oreochromis mossambicus, 81 red-breasted bream, Tilapia rendalli swierstrae and 32 large-mouthed bream, Serranochromis meridianus, caught in the Sabie, Crocodile and Olifants Rivers in the southern and central regions of the Kruger National Park, were collected, identified and counted. A single Camallanus sp. male was recovered from one of the mudsuckers; Capillaria spp. from three catfish and one squeaker; philometrid nematodes from two silver barbel, 15 squeakers and a large-mouthed bream; Paracamallanus cyathopharynx from one tiger-fish, 80 catfish, 28 silver barbel and one squeaker; Procamallanus laeviconchus from a single catfish; Rhabdochona esseniae from six large-scaled yellowfish; Rhabdochona versterae from 14 spot-tailed robbers; Rhabdochona spp. from 20 catfish, 17 silver barbel, eight squeakers, two eels, one large-mouthed bream and two red-breasted bream; Raillietnema synodontisi from 33 squeakers; Spinitectus petterae from 37 catfish; Spinitectus zambezensis from 55 squeakers; Spinitectus spp. from one tiger-fish and four silver barbel, and Spirocamallanus daleneae and Synodontisia thelastomoides from 33 and 35 squeakers, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. A Novel Meloidogyne incognita Effector Misp12 Suppresses Plant Defense Response at Latter Stages of Nematode Parasitism

    Science.gov (United States)

    Xie, Jialian; Li, Shaojun; Mo, Chenmi; Wang, Gaofeng; Xiao, Xueqiong; Xiao, Yannong

    2016-01-01

    Secreted effectors in plant root-knot nematodes (RKNs, or Meloidogyne spp.) play key roles in their parasite processes. Currently identified effectors mainly focus on the early stage of the nematode parasitism. There are only a few reports describing effectors that function in the latter stage. In this study, we identified a potential RKN effector gene, Misp12, that functioned during the latter stage of parasitism. Misp12 was unique in the Meloidogyne spp., and highly conserved in Meloidogyne incognita. It encoded a secretory protein that specifically expressed in the dorsal esophageal gland, and highly up-regulated during the female stages. Transient expression of Misp12-GUS-GFP in onion epidermal cell showed that Misp12 was localized in cytoplast. In addition, in planta RNA interference targeting Misp12 suppressed the expression of Misp12 in nematodes and attenuated parasitic ability of M. incognita. Furthermore, up-regulation of jasmonic acid (JA) and salicylic acid (SA) pathway defense-related genes in the virus-induced silencing of Misp12 plants, and down-regulation of SA pathway defense-related genes in Misp12-expressing plants indicated the gene might be associated with the suppression of the plant defense response. These results demonstrated that the novel nematode effector Misp12 played a critical role at latter parasitism of M. incognita. PMID:27446188

  3. Discovery of quantitative trait loci for resistance to parasitic nematode infection in sheep: I. Analysis of outcross pedigrees

    Directory of Open Access Journals (Sweden)

    Greer Gordon J

    2006-07-01

    Full Text Available Abstract Background Currently most pastoral farmers rely on anthelmintic drenches to control gastrointestinal parasitic nematodes in sheep. Resistance to anthelmintics is rapidly increasing in nematode populations such that on some farms none of the drench families are now completely effective. It is well established that host resistance to nematode infection is a moderately heritable trait. This study was undertaken to identify regions of the genome, quantitative trait loci (QTL that contain genes affecting resistance to parasitic nematodes. Results Rams obtained from crossing nematode parasite resistant and susceptible selection lines were used to derive five large half-sib families comprising between 348 and 101 offspring per sire. Total offspring comprised 940 lambs. Extensive measurements for a range of parasite burden and immune function traits in all offspring allowed each lamb in each pedigree to be ranked for relative resistance to nematode parasites. Initially the 22 most resistant and 22 most susceptible progeny from each pedigree were used in a genome scan that used 203 microsatellite markers spread across all sheep autosomes. This study identified 9 chromosomes with regions showing sufficient linkage to warrant the genotyping of all offspring. After genotyping all offspring with markers covering Chromosomes 1, 3, 4, 5, 8, 12, 13, 22 and 23, the telomeric end of chromosome 8 was identified as having a significant QTL for parasite resistance as measured by the number of Trichostrongylus spp. adults in the abomasum and small intestine at the end of the second parasite challenge. Two further QTL for associated immune function traits of total serum IgE and T. colubiformis specific serum IgG, at the end of the second parasite challenge, were identified on chromosome 23. Conclusion Despite parasite resistance being a moderately heritable trait, this large study was able to identify only a single significant QTL associated with it. The QTL

  4. Some aspects of the taxonomy and biology of adult spirurine nematodes parasitic in fishes: a review.

    Science.gov (United States)

    Moravec, Frantisek

    2007-11-01

    About 300 species belonging to four superfamilies (Gnathostomatoidea, Habronematoidea, Physalopteroidea and Thelazioidea) of the nematode suborder Spirurina are known as the adult parasites of freshwater, brackish-water and marine fishes. They are placed in four families, of which the Gnathostomatidae, including Echinocephalus with a few species and the monotypic Metaleptus, are parasites of elasmobranchs, whereas Ancyracanthus contains one species in teleosts; the Physalopteridae is represented in fish by four genera, Bulbocephalus, Heliconema, Paraleptus and Proleptus, each with several species in both elasmobranchs and teleosts. The majority of fish spirurines belongs to the Rhabdochonidae, which includes 10 genera (Beaninema, Fellicola, Hepatinema, Heptochona, Johnstonmawsonia, Megachona, Pancreatonema, Prosungulonema, Rhabdochona and Vasorhabdochona) of species parasitizing mainly teleosts, rarely elasmobranchs, and the Cystidicolidae with about 23 genera (Ascarophis, Caballeronema, Capillospirura, Comephoronema, Crenatobronema, Cristitectus, Ctenascarophis, Cyclozone, Cystidicola, Cystidicoloides, Johnstonmawsonoides, Metabronema, Moravecnema, Neoascarophis, Parascarophis, Prospinitectus, Pseudascarophis, Pseudoproleptus, Salvelinema, Similascarophis, Spinitectoides, Spinitectus, Sterliadochona), with many species parasitic in teleosts only. Because of difficulties in studying fish spirurines, associated with their morphological and biological peculiarities, most species of these parasites are poorly known. It is apparent that their present classification system does not reflect phylogenetic relationships and a taxonomic revision of this nematode group, based on detailed morphological (including SEM and TEM), life history and molecular studies of individual species, is quite necessary. In Cystidicolidae, several genera have been based on details in the cephalic structures visible only with the aid of SEM, but it will be evident whether or not these tiny

  5. An automated high-throughput system for phenotypic screening of chemical libraries on C. elegans and parasitic nematodes.

    Science.gov (United States)

    Partridge, Frederick A; Brown, Anwen E; Buckingham, Steven D; Willis, Nicky J; Wynne, Graham M; Forman, Ruth; Else, Kathryn J; Morrison, Alison A; Matthews, Jacqueline B; Russell, Angela J; Lomas, David A; Sattelle, David B

    2017-12-02

    Parasitic nematodes infect hundreds of millions of people and farmed livestock. Further, plant parasitic nematodes result in major crop damage. The pipeline of therapeutic compounds is limited and parasite resistance to the existing anthelmintic compounds is a global threat. We have developed an INVertebrate Automated Phenotyping Platform (INVAPP) for high-throughput, plate-based chemical screening, and an algorithm (Paragon) which allows screening for compounds that have an effect on motility and development of parasitic worms. We have validated its utility by determining the efficacy of a panel of known anthelmintics against model and parasitic nematodes: Caenorhabditis elegans, Haemonchus contortus, Teladorsagia circumcincta, and Trichuris muris. We then applied the system to screen the Pathogen Box chemical library in a blinded fashion and identified compounds already known to have anthelmintic or anti-parasitic activity, including tolfenpyrad, auranofin, and mebendazole; and 14 compounds previously undescribed as anthelmintics, including benzoxaborole and isoxazole chemotypes. This system offers an effective, high-throughput system for the discovery of novel anthelmintics. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Biological control of Otiorhynchus sulcatus by insect parasitic nematodes, Heterorhabditis spp., at low temperatures : a systems analytical approach

    NARCIS (Netherlands)

    Westerman, P.R.

    1997-01-01

    The black vine weevil, Otiorhynchus sulcatus, is an important pest in ornamentals and nursery stock in The Netherlands. The larvae, which feed on the root system of the plant, can be controlled by insect parasitic nematodes, Heterorhabditis.

  7. The genome of the yellow potato cyst nematode, Globodera rostochiensis, reveals insights into the basis of parasitism and virulence

    NARCIS (Netherlands)

    Eves-van den Akker, Sebastian; Laetsch, Dominik R.; Thorpe, Peter; Lilley, Catherine J.; Danchin, Etienne G.J.; Rocha, Da Martine; Rancurel, Corinne; Holroyd, Nancy E.; Cotton, James A.; Szitenberg, Amir; Grenier, Eric; Montarry, Josselin; Mimee, Benjamin; Duceppe, Marc Olivier; Boyes, Ian; Marvin, Jessica M.C.; Jones, Laura M.; Yusup, Hazijah B.; Lafond-Lapalme, Joël; Esquibet, Magali; Sabeh, Michael; Rott, Michael; Overmars, Hein; Finkers-Tomczak, Anna; Smant, Geert; Koutsovoulos, Georgios; Blok, Vivian; Mantelin, Sophie; Cock, Peter J.A.; Phillips, Wendy; Henrissat, Bernard; Urwin, Peter E.; Blaxter, Mark; Jones, John T.

    2016-01-01

    Background: The yellow potato cyst nematode, Globodera rostochiensis, is a devastating plant pathogen of global economic importance. This biotrophic parasite secretes effectors from pharyngeal glands, some of which were acquired by horizontal gene transfer, to manipulate host processes and

  8. Controlled Atmosphere Temperature Treatment as Sustainable Alternative to Control Strawberry Tarsenomid Mites and Plant Parasitic Nematodes in Strawberry Plants

    NARCIS (Netherlands)

    Kruistum, van G.; Hoek, H.; Molendijk, L.P.G.

    2012-01-01

    High qualified strawberry (Fragaria × ananassa) planting material, mainly for export, is produced by Dutch growers on circa 1100 ha field area in The Netherlands. Planting stock must be destroyed if strawberry tarsonemid mite (Phytonemus pallidus) or infection by the plant parasitic nematode

  9. Observations on two nematode species parasitizing freshwater fishes in Thailand, including Spinitectus thaiensis sp nov (Cystidicolidae) from Pseudomystus siamensis (Bagridae)

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Yooyen, T.

    2011-01-01

    Roč. 56, č. 1 (2011), 58-66 ISSN 1230-2821 Institutional research plan: CEZ:AV0Z60220518 Keywords : Parasitic nematode * freshwater fish * Thailand Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 0.789, year: 2011

  10. A preliminary proteomic characterisation of extracellular vesicles released by the ovine parasitic nematode, Teladorsagia circumcincta.

    Science.gov (United States)

    Tzelos, Thomas; Matthews, Jacqueline B; Buck, Amy H; Simbari, Fabio; Frew, David; Inglis, Neil F; McLean, Kevin; Nisbet, Alasdair J; Whitelaw, C Bruce A; Knox, David P; McNeilly, Tom N

    2016-05-15

    Teladorsagia circumcincta is a major cause of ovine parasitic gastroenteritis in temperate climatic regions. The development of high levels of anthelmintic resistance in this nematode species challenges its future control. Recent research indicates that many parasite species release extracellular vesicles into their environment, many of which have been classified as endocytic in origin, termed exosomes. These vesicles are considered to play important roles in the intercellular communication between parasites and their hosts, and thus represent potentially useful targets for novel control strategies. Here, we demonstrate that exosome-like extracellular vesicles can be isolated from excretory-secretory (ES) products released by T. circumcincta fourth stage larvae (Tci-L4ES). Furthermore, we perform a comparative proteomic analysis of vesicle-enriched and vesicle-free Tci-L4ES. Approximately 73% of the proteins identified in the vesicle-enriched fraction were unique to this fraction, whilst the remaining 27% were present in both vesicle-enriched and vesicle-free fraction. These unique proteins included structural proteins, nuclear proteins, metabolic proteins, proteolytic enzymes and activation-associated secreted proteins. Finally, we demonstrate that molecules present within the vesicles-enriched material are targets of the IgA and IgG response in T. circumcincta infected sheep, and could potentially represent useful targets for future vaccine intervention studies. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. EFFICACY OF ENDOPHYTIC BACTERIA IN REDUCING PLANT PARASITIC NEMATODE Pratylenchus brachyurus

    Directory of Open Access Journals (Sweden)

    Rita Harni

    2014-04-01

    Full Text Available Pratylenchus brachyurus is a major parasitic nematode on patchouli that reduces plant production up to 85%. The use of endophytic bacteria is promising for controlling nematode and promoting plant growth through production of phytohormones and enhancing the availability of soil nutrients. The objective of the study was to evaluate the efficacy of endophytic bacteria to control P. brachyurus on patchouli plant and its influence on plant productions (plant fresh weight and patchouli oil. The study was conducted at Cimanggu Experimental Garden and Laboratory of the Indonesian Spice and Medicinal Crops Research Institute (ISMECRI, Bogor, West Java. The experi-ment was designed in a randomized block with seven treatments and eight replications; each replication consisted of 10 plants. The treatments evaluated were five isolates of endophytic bacteria (Achromobacter xylosoxidans TT2, Alcaligenes faecalis NJ16, Pseudomonas putida EH11, Bacillus cereus MSK and Bacillus subtilis NJ57, synthetic nematicide as a reference, and non-treated plant as a control.  Four-week old patchouli plants of cv. Sidikalang were treated by soaking the roots in suspension of endophytic bacteria (109 cfu  ml-1 for one hour before trans-planting to the field. At one month after planting, the plants were drenched with the bacterial suspension as much as 100 ml per plant. The results showed that applications of the endophytic bacteria could suppress the nematode populations (52.8-80% and increased plant weight (23.62-57.48% compared to the control. The isolate of endophytic bacterium Achromobacter xylosoxidans TT2 was the best and comparable with carbofuran.

  12. A novel copro-diagnostic molecular method for qualitative detection and identification of parasitic nematodes in amphibians and reptiles.

    Directory of Open Access Journals (Sweden)

    Lucas G Huggins

    Full Text Available Anthropogenic disturbance via resource acquisition, habitat fragmentation and climate change, amongst other factors, has led to catastrophic global biodiversity losses and species extinctions at an accelerating rate. Amphibians are currently one of the worst affected classes with at least a third of species categorised as being threatened with extinction. At the same time, they are also critically important for many habitats and provide man with a powerful proxy for ecosystem health by acting as a bioindicator group. Whilst the causes of synchronised amphibian losses are varied recent research has begun to highlight a growing role that macroparasites are playing in amphibian declines. However, diagnosing parasite infection in the field can be problematic, principally relying on collection and euthanasia of hosts, followed by necropsy and morphological identification of parasites in situ. The current study developed a non-invasive PCR-based methodology for sensitive detection and identification of parasitic nematode DNA released in the faeces of infected amphibians as egg or tissue fragments (environmental DNA. A DNA extraction protocol optimised for liberation of DNA from resilient parasite eggs was developed alongside the design of a novel, nematode universal, degenerate primer pair, thus avoiding the difficulties of using species specific primers in situations where common parasite species are unknown. Used in conjunction this protocol and primer pair was tested on a wide range of faecal samples from captive and wild amphibians. The primers and protocol were validated and detected infections, including a Railletnema nematode infection in poison dart frogs from ZSL London Zoo and Mantella cowani frogs in the wild. Furthermore, we demonstrate the efficacy of our PCR-based protocol for detecting nematode infection in other hosts, such as the presence of pinworm (Aspiculuris in two tortoise species and whipworm (Trichuris muris in mice. Our

  13. A novel copro-diagnostic molecular method for qualitative detection and identification of parasitic nematodes in amphibians and reptiles.

    Science.gov (United States)

    Huggins, Lucas G; Michaels, Christopher J; Cruickshank, Sheena M; Preziosi, Richard F; Else, Kathryn J

    2017-01-01

    Anthropogenic disturbance via resource acquisition, habitat fragmentation and climate change, amongst other factors, has led to catastrophic global biodiversity losses and species extinctions at an accelerating rate. Amphibians are currently one of the worst affected classes with at least a third of species categorised as being threatened with extinction. At the same time, they are also critically important for many habitats and provide man with a powerful proxy for ecosystem health by acting as a bioindicator group. Whilst the causes of synchronised amphibian losses are varied recent research has begun to highlight a growing role that macroparasites are playing in amphibian declines. However, diagnosing parasite infection in the field can be problematic, principally relying on collection and euthanasia of hosts, followed by necropsy and morphological identification of parasites in situ. The current study developed a non-invasive PCR-based methodology for sensitive detection and identification of parasitic nematode DNA released in the faeces of infected amphibians as egg or tissue fragments (environmental DNA). A DNA extraction protocol optimised for liberation of DNA from resilient parasite eggs was developed alongside the design of a novel, nematode universal, degenerate primer pair, thus avoiding the difficulties of using species specific primers in situations where common parasite species are unknown. Used in conjunction this protocol and primer pair was tested on a wide range of faecal samples from captive and wild amphibians. The primers and protocol were validated and detected infections, including a Railletnema nematode infection in poison dart frogs from ZSL London Zoo and Mantella cowani frogs in the wild. Furthermore, we demonstrate the efficacy of our PCR-based protocol for detecting nematode infection in other hosts, such as the presence of pinworm (Aspiculuris) in two tortoise species and whipworm (Trichuris muris) in mice. Our environmental DNA

  14. Canine and feline cardiopulmonary parasitic nematodes in Europe: emerging and underestimated.

    Science.gov (United States)

    Traversa, Donato; Di Cesare, Angela; Conboy, Gary

    2010-07-23

    Cardiopulmonary nematodes of dogs and cats cause parasitic diseases of central relevance in current veterinary practice. In the recent past the distribution of canine and feline heartworms and lungworms has increased in various geographical areas, including Europe. This is true especially for the metastrongyloids Aelurostrongylus abstrusus, Angiostrongylus vasorum and Crenosoma vulpis, the filarioid Dirofilaria immitis and the trichuroid Eucoleus aerophilus (syn. Capillaria aerophila). The reasons of this emergence are little known but many drivers such as global warming, changes in vector epidemiology and movements in animal populations, may be taken into account. The purpose of this article is to review the knowledge of the most important heartworm and lungworm infections of dogs and cats in Europe. In particular recent advances in epidemiology, clinical and control are described and discussed.

  15. Canine and feline cardiopulmonary parasitic nematodes in Europe: emerging and underestimated

    Directory of Open Access Journals (Sweden)

    Conboy Gary

    2010-07-01

    Full Text Available Abstract Cardiopulmonary nematodes of dogs and cats cause parasitic diseases of central relevance in current veterinary practice. In the recent past the distribution of canine and feline heartworms and lungworms has increased in various geographical areas, including Europe. This is true especially for the metastrongyloids Aelurostrongylus abstrusus, Angiostrongylus vasorum and Crenosoma vulpis, the filarioid Dirofilaria immitis and the trichuroid Eucoleus aerophilus (syn. Capillaria aerophila. The reasons of this emergence are little known but many drivers such as global warming, changes in vector epidemiology and movements in animal populations, may be taken into account. The purpose of this article is to review the knowledge of the most important heartworm and lungworm infections of dogs and cats in Europe. In particular recent advances in epidemiology, clinical and control are described and discussed.

  16. Nematode parasites of commercially important fish from the southeast coast of Brazil: Morphological and genetic insight.

    Science.gov (United States)

    Di Azevedo, Maria Isabel N; Iñiguez, Alena M

    2018-02-21

    Studies of nematofauna of teleost fish from the Brazilian coast are relatively scarce and limited to identification based on morphology. The objective of the present study was to determine the diversity and prevalence of nematode parasites in teleost fish from the southeast Atlantic coast of Rio de Janeiro, through morphological, molecular, and ecological approaches. Parasites were collected from sixty specimens each of Genypterus brasiliensis, Micropogonias furnieri, and Mullus argentinae obtained in winters and summers of 2012–2014. Morphological and genetic characterization was conducted using light microscopy and the molecular targets 18S rDNA, ITS1, and mtDNA cox2. Nematodes identified in M. furnieri were Cucculanus genypteri (n = 1575, P = 98.3%) and Hysterothylacium deardorffoverstreetorum (s.l.) (n = 2, P = 3.3%); in G. brasiliensis were Dichelyne (Cucullanellus) sciaenidicola (n = 99, P = 33.3%), Cucculanus pulcherrimus (n = 45, P = 18.3%), Hysterothylacium deardorffoverstreetorum (s.l.) (n = 3, P = 5%), and Anisakis typica (n = 1, P = 1.7%); and, in M. argentinae, were H. deardorffoverstreetorum (s.l.) (n = 146, P = 48.3%), and Procamallanus (Spirocamallanus) halitrophus (n = 4, P = 6.7%). DNA sequence data of C. genypteri, C. pulcherrimus, D. (C.) sciaenidicola, and P. (S.) halitrophus were reported for the first time. New host records are M. argentinae for P. (S.) halitrophus, M. furnieri for A. typica, while H. deardorffoverstreetorum (s.l.) was found in all three fish species. Intestine showed significantly higher intensity than other sites, and no significant seasonal variation in parasitological indices was observed. Hysterothylacium specimens (n = 6) were found in fish muscle, potentially a public health concern.

  17. Draft genome of neurotropic nematode parasite Angiostrongylus cantonensis, causative agent of human eosinophilic meningitis.

    Science.gov (United States)

    Yong, Hoi-Sen; Eamsobhana, Praphathip; Lim, Phaik-Eem; Razali, Rozaimi; Aziz, Farhanah Abdul; Rosli, Nurul Shielawati Mohamed; Poole-Johnson, Johan; Anwar, Arif

    2015-08-01

    Angiostrongylus cantonensis is a bursate nematode parasite that causes eosinophilic meningitis (or meningoencephalitis) in humans in many parts of the world. The genomic data from A. cantonensis will form a useful resource for comparative genomic and chemogenomic studies to aid the development of diagnostics and therapeutics. We have sequenced, assembled and annotated the genome of A. cantonensis. The genome size is estimated to be ∼260 Mb, with 17,280 genomic scaffolds, 91X coverage, 81.45% for complete and 93.95% for partial score based on CEGMA analysis of genome completeness. The number of predicted genes of ≥300 bp was 17,482. A total of 7737 predicted protein-coding genes of ≥50 amino acids were identified in the assembled genome. Among the proteins of known function, kinases are the most abundant followed by transferases. The draft genome contains 34 excretory-secretory proteins (ES), a minimum of 44 Nematode Astacin (NAS) metalloproteases, 12 Homeobox (HOX) genes, and 30 neurotransmitters. The assembled genome size (260 Mb) is larger than those of Pristionchus pacificus, Caenorhabditis elegans, Necator americanus, Caenorhabditis briggsae, Trichinella spiralis, Brugia malayi and Loa loa, but smaller than Haemonchus contortus and Ascaris suum. The repeat content (25%) is similar to H. contortus. The GC content (41.17%) is lower compared to P. pacificus (42.7%) and H. contortus (43.1%) but higher compared to C. briggsae (37.69%), A. suum (37.9%) and N. americanus (40.2%) while the scaffold N50 is 42,191. This draft genome will facilitate the understanding of many unresolved issues on the parasite and the disorder it causes. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Climate-driven changes to the spatio-temporal distribution of the parasitic nematode, Haemonchus contortus, in sheep in Europe.

    Science.gov (United States)

    Rose, Hannah; Caminade, Cyril; Bolajoko, Muhammad Bashir; Phelan, Paul; van Dijk, Jan; Baylis, Matthew; Williams, Diana; Morgan, Eric R

    2016-03-01

    Recent climate change has resulted in changes to the phenology and distribution of invertebrates worldwide. Where invertebrates are associated with disease, climate variability and changes in climate may also affect the spatio-temporal dynamics of disease. Due to its significant impact on sheep production and welfare, the recent increase in diagnoses of ovine haemonchosis caused by the nematode Haemonchus contortus in some temperate regions is particularly concerning. This study is the first to evaluate the impact of climate change on H. contortus at a continental scale. A model of the basic reproductive quotient of macroparasites, Q0 , adapted to H. contortus and extended to incorporate environmental stochasticity and parasite behaviour, was used to simulate Pan-European spatio-temporal changes in H. contortus infection pressure under scenarios of climate change. Baseline Q0 simulations, using historic climate observations, reflected the current distribution of H. contortus in Europe. In northern Europe, the distribution of H. contortus is currently limited by temperatures falling below the development threshold during the winter months and within-host arrested development is necessary for population persistence over winter. In southern Europe, H. contortus infection pressure is limited during the summer months by increased temperature and decreased moisture. Compared with this baseline, Q0 simulations driven by a climate model ensemble predicted an increase in H. contortus infection pressure by the 2080s. In northern Europe, a temporal range expansion was predicted as the mean period of transmission increased by 2-3 months. A bimodal seasonal pattern of infection pressure, similar to that currently observed in southern Europe, emerges in northern Europe due to increasing summer temperatures and decreasing moisture. The predicted patterns of change could alter the epidemiology of H. contortus in Europe, affect the future sustainability of contemporary

  19. The effects of Brassica green manures on plant parasitic and free living nematodes used in combination with reduced rates of synthetic nematicides.

    Science.gov (United States)

    Riga, Ekaterini

    2011-06-01

    Brassica plants once incorporated into soil as green manures have recently been shown to have biofumigant properties and have the potential of controlling plant-parasitic nematodes. In Washington State, plant-parasitic nematodes are successfully managed with synthetic nematicides. However, some of the synthetic nematicides became unavailable recently or their supply is limited leaving growers with few choices to control plant-parasitic nematodes. The objective of this project was to evaluate the effects of Brassica green manures on their own and in combination with reduced rates of synthetic nematicides on plant-parasitic nematodes and free living nematodes. In a greenhouse experiment and field trials in three seasons, Brassica green manures in combination with half the recommended rate of 1,3-dichloropropene (1,3-D, Telone) reduced root knot nematode, Meloidogyne chitwoodi to below detection levels, and reduced lesion nematodes, Pratylenchus penetrans and stubby root nematodes, Paratrichodorus allius, to below economic thresholds. The combination treatments did not affect the beneficial free-living nematode populations and the non-pathogenic Pseudomonas. The total cost of growing and soil-incorporating Brassica crops as green manures in combination with reduced rates of 1,3-D was approximately 35% lower than the present commercial costs for application for the full rate of this fumigant. Integrating conventional management practices with novel techniques fosters sustainability of production systems and can increase economic benefit to producers while reducing chemical input.

  20. Aquatic molluscs as auxiliary hosts for terrestrial nematode parasites: implications for pathogen transmission in a changing climate.

    Science.gov (United States)

    Morley, N J

    2010-06-01

    Nematodes are common parasites of molluscs but are often overlooked. Both metastrongyloid and rhabditoid species dominate the fauna within land snail and slug populations. Nevertheless, a key characteristic of many laboratory studies is the ability of these terrestrial nematodes to utilize aquatic molluscs as auxiliary hosts. The significance of this to the ecology of the parasite has never been evaluated. There is increasing concern as to the impact of climate change on the epidemiology of many parasitic diseases. In particular, it has been suggested that host switching may increase under the pressure of extreme climatic conditions. It is therefore timely to assess the role that aquatic molluscs may play in transmitting terrestrial nematodes, which include species of medical and veterinary importance such as Angiostrongylus cantonensis, A. vasorum, and Muellerius capillaris. The present review assesses the mechanisms of terrestrial nematode transmission through aquatic molluscs focusing on metastrongyloid and rhabditoid species, the importance of variable susceptibility of molluscan hosts, field studies on natural occurrence within aquatic habitats, and the impact of extreme climatic events (floods and droughts) that may increase in frequency under climate change.

  1. Plant-parasitic nematodes associated with olive tree (Olea europaea L.) with a focus on the Mediterranean Basin: a review.

    Science.gov (United States)

    Ali, Nadine; Chapuis, Elodie; Tavoillot, Johannes; Mateille, Thierry

    2014-01-01

    The olive tree (Olea europaea ssp. europaea.) is one of the most ancient cultivated trees. It is an emblematic species owing to its ecological, economic and cultural importance, especially in the Mediterranean Basin. Plant-parasitic nematodes are major damaging pests on olive trees, mainly in nurseries. They significantly contribute to economic losses in the top-ten olive-producing countries in the world. However, the damages they induce in orchards and nurseries are specifically documented only in a few countries. This review aims to update knowledge about the olive-nematode pathosystem by: (1) updating the list of plant-parasitic nematodes associated with olive trees; (2) analysing their diversity (taxonomic level, trophic groups, dominance of taxa), which allowed us (i) to assess the richness observed in each country, and (ii) to exhibit and describe the most important taxa able to induce damages on olive trees such as: Meloidogyne, Pratylenchus, Helicotylenchus, Xiphinema, Tylenchulus, Rotylenchulus, Heterodera (distribution especially in the Mediterranean Basin, pathogenicity and reactions of olive trees); (3) describing some management strategies focusing on alternative control methods; (4) suggesting new approaches for controlling plant-parasitic nematodes based on the management of the diversity of their communities, which are structured by several environmental factors such as olive diversity (due to domestication of wild olive in the past, and to breeding now), cropping systems (from traditional to high-density orchards), irrigation, and terroirs. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  2. Use of the arbuscular mycorrhizal fungus Glomus intraradices as biological control agent of the nematode Nacobbus aberrans parasitizing tomato

    Directory of Open Access Journals (Sweden)

    Nicolás Marro

    2014-10-01

    Full Text Available The plant-parasitic nematode Nacobbus aberrans is an endoparasite that induces gall formation in the roots and causes severe losses to diverse crops. Some populations of this nematode show preference for certain hosts, revealing the existence of "races/groups" with different behaviour and making nematode management difficult. A possible biological control alternative to reduce the damage caused by this species may be the use of arbuscular mycorrhizal fungi (AMF. In the present work, the effect of Glomus intraradices on tomato plants inoculated with the nematode at transplanting and three weeks later was tested. At 60 days, the following parameters were estimated: percentage of AMF colonization, root and aerial dry weight, number of galls and egg masses, and reproduction factor (RF=final population/initial population of N. aberrans. AMF colonization was higher in the presence of the nematode. The use of AMF favoured tomato biomass and reduced the number of galls and RF on the plants inoculated with the nematode at transplanting.

  3. Identification of plant parasitic nematodes in guava (Psidium guajava L.), at the municipality of Manizales (Caldas), Colombia

    International Nuclear Information System (INIS)

    Guzman Piedrahita, Oscar Adrian; Castano Zapata, Jairo

    2010-01-01

    The future of the colombian fruticulture is in permanent crops, such as tropical fruits, amongst them guava. This research had as objective to identify the parasitic nematodes of this crop. The study was conducted at the region of La Cabana, municipality of Manizales, Caldas, located at 1.100 most, average annual temperature of 24 Celsius degrade and annual precipitation of 2.100 mm. The sampling was carried out in a plantation of guava Pera of 3 years old. At random were sampled 10 trees, and from each one was obtained samples of 100 g of roots and 500 g of soil. The extraction of nematodes was done by following the method of centrifugation and sugar flotation. It was identified: Meloidogyne, Helicotylenchus and Pratylenchus, being the most important the root-knob nematode Meloidogyne spp.

  4. Brassicaceous Seed Meals as Soil Amendments to Suppress the Plant-parasitic Nematodes Pratylenchus penetrans and Meloidogyne incognita1

    Science.gov (United States)

    Meyer, S. L. F.; Morra, M. J.

    2009-01-01

    Brassicaceous seed meals are the residual materials remaining after the extraction of oil from seeds; these seed meals contain glucosinolates that potentially degrade to nematotoxic compounds upon incorporation into soil. This study compared the nematode-suppressive ability of four seed meals obtained from Brassica juncea ‘Pacific Gold’, B. napus ‘Dwarf Essex’ and ‘Sunrise’, and Sinapis alba ‘IdaGold’, against mixed stages of Pratylenchus penetrans and Meloidogyne incognita second-stage juveniles (J2). The brassicaceous seed meals were applied to soil in laboratory assays at rates ranging from 0.5 to 10.0% dry w/w with a nonamended control included. Nematode mortality was assessed after 3 days of exposure and calculated as percentage reduction compared to a nonamended control. Across seed meals, M. incognita J2 were more sensitive to the brassicaceous seed meals compared to mixed stages of P. penetrans. Brassica juncea was the most nematode-suppressive seed meal with rates as low as 0.06% resulting in > 90% suppression of both plant-parasitic nematodes. In general B. napus ‘Sunrise’ was the least nematode-suppressive seed meal. Intermediate were the seed meals of S. alba and B. napus ‘Dwarf Essex’; 90% suppression was achieved at 1.0% and 5.0% S. alba and 0.25% and 2.5% B. napus ‘Dwarf Essex’, for M. incognita and P. penetrans, respectively. For B. juncea, seed meal glucosinolate-degradation products appeared to be responsible for nematode suppression; deactivated seed meal (wetted and heated at 70 °C for 48 hr) did not result in similar P. penetrans suppression compared to active seed meal. Sinapis alba seed meal particle size also played a role in nematode suppression with ground meal resulting in 93% suppression of P. penetrans compared with 37 to 46% suppression by pelletized S. alba seed meal. This study demonstrates that all seed meals are not equally suppressive to nematodes and that care should be taken when selecting a source

  5. The adaptive significance of inquiline parasite workers

    DEFF Research Database (Denmark)

    Sumner, Seirian; Nash, David R; Boomsma, Jacobus J

    2003-01-01

    Social parasites exploit the socially managed resources of their host's society. Inquiline social parasites are dependent on their host throughout their life cycle, and so many of the traits inherited from their free-living ancestor are removed by natural selection. One trait that is commonly lost...... a vital role in ensuring the parasite's fitness. We show that the presence of these parasite workers has a positive effect on the production of parasite sexuals and a negative effect on the production of host sexuals. This suggests that inquiline workers play a vital role in suppressing host queen...

  6. Understanding the interaction between an obligate hyperparasitic bacterium, Pasteuria penetrans and its obligate plant-parasitic nematode host, Meloidogyne spp.

    Science.gov (United States)

    Davies, Keith G

    2009-01-01

    Pasteuria penetrans is an endospore-forming bacterium, which is a hyperparasite of root-knot nematodes Meloidogyne spp. that are economically important pests of a wide range of crops. The life cycle of the bacterium and nematode are described with emphasis on the bacterium's potential as a biocontrol agent. Two aspects that currently prohibit the commercial development of the bacterium as a biocontrol agent are the inability to culture it outside its host and its host specificity. Vegetative growth of the bacterium is possible in vitro; however, getting the vegetative stages of the bacterium to enter sporogenesis has been problematic. Insights from genomic survey sequences regarding the role of cation concentration and the phosphorylation of Spo0F have proved useful in inducing vegetative bacteria to sporulate. Similarly, genomic data have also proved useful in understanding the attachment of endospores to the cuticle of infective nematode juveniles, and a Velcro-like model of spore attachment is proposed that involves collagen-like fibres on the surface of the endospore interacting with mucins on the nematode cuticle. Ecological studies of the interactions between Daphnia and Pasteuria ramosa are examined and similarities are drawn between the co-evolution of virulence in the Daphnia system and that of plant-parasitic nematodes.

  7. Response of laboratory-adapted human hookworm and other nematodes to ivermectin.

    Science.gov (United States)

    Rajasekariah, G R; Deb, B N; Dhage, K R; Bose, S

    1986-12-01

    The activity of ivermectin was examined in Necator americanus, a human hookworm, adapted to the laboratory hamster. A dose of 30 mg kg-1 X 1 or 10 mg kg-1 X 2 was required for complete clearance of pre-adult N. americanus; however, hamsters carrying adult N. americanus were completely cured of infection by doses of 15 mg kg-1 or 7.5 mg kg-1 X 2. The doses of ivermectin required for complete elimination of N. americanus were much higher than those reported for other intestinal nematodes. The probable reasons for these higher doses are discussed. Tests were also carried out with other rodent parasites, namely Nematospiroides dubius, Strongyloides ratti and Trichuris muris. Doses as low as 0.3 mg kg-1 X 1 completely eliminated adult N. dubius from mice, whereas++ S. ratti needed a repeated dose (0.3 mg kg-1 X 2). None of the mice was cured of T. muris infection even at doses of 10 mg kg-1 X 2, although some degree of cure was apparent at the toxic dose. It thus appears that ivermectin is in no way superior in its activity against N. americanus and T. muris than the existing anthelmintics.

  8. Effects of Entomopathogenic Nematodes on the Development of Root-knot Nematode and Aphid, and on the Parasitism of Aphid Parasitoid in Tobacco

    Directory of Open Access Journals (Sweden)

    WANG Yu-kun

    2017-05-01

    Full Text Available Entomopathogenic nematodes(EPN which is recognized as a kind of potential biological control material have been paid more and more attention in recent years. In the present study, we selected tobacco(Nicotiana tabacum as the object to study the effects of EPN (Steinernema carpocapsae and Heterorhabditis bacteriophoraon the development of root-knot nematodes and aphid (Myzus persicae, and on the parasitism of aphid parasitoid (Aphidius gifuensis in tobacco. The results showed that (1Under the condition of the artificial removal of aphids, the number of egg per plant was significantly lower under the EPN treatments than control treatment(PS. carpocapsae treatment than the other treatments(PH. bacteriophora cadaver treatment were 89.6 individual·plant-1 and 0.996 g·plant-1, 99.8 individual·plant-1 and 3.258 g·plant-1, 76.6 individual·plant-1 and 1.643 g·plant-1, respectively, indicating that EPN treatment could decrease the number of aphids per mass; (3On the first three observation dates, the number of aphid mummies was significantly lower under S. carpocapsae cadaver treatment than H. bacteriophora cadaver treatment. The results indicated that EPN treatments in tobacco could affect the development of root-knot nematode, and had impact on the development of aphids and the activities of aphid parasitoid by "bottom-up" approach, and these effects were affected by the species of EPN.

  9. Parasites of South African freshwater fish. I. Some nematodes of the catfish [Clarias gariepinus (Burchell, 1822)] from the Hartbeespoort Dam.

    Science.gov (United States)

    Boomker, J

    1982-03-01

    A seasonal study of the parasites of fish in the Hartbeespoort Dam was undertaken in 1979. This paper deals with 4 nematode species recovered from catfish, namely, Paracamallanus cyathopharynx (Baylis, 1923), Procamallanus laeviconchus (Wedl, 1862), Contracaecum sp. and Skrjabinocara sp. Total numbers of parasites recovered are tabulated and their seasonal variation illustrated diagrammatically. Paracamallanus cyathopharynx was recovered from 23 out of 43 catfish examined and Procamallanus laeviconchus from 13, while Contracaecum sp. larvae were present in all the catfish. Skrjabinocara sp. was recovered from 1 catfish only, but it is not regarded as being parasitic in fish, as it was also recovered from 1 out of 4 cormorant examined. Paracamallanus cyathopharynx and Procamallanus laeviconchus are illustrated and the measurements of the Hartbeespoort Dam material compared with those given by various authors who recovered the same parasites from other fish species elsewhere in Africa.

  10. Gnathostomatidae nematode parasite of Colomesus psittacus (Osteichthyes, Tetraodontiformes) in the Ilha de Marajó, Brazilian Amazon.

    Science.gov (United States)

    Pinheiro, Raul Henrique da Silva; Santana, Ricardo Luís Sousa; Melo, Francisco Tiago Vasconcelos; Santos, Jeannie Nascimento Dos; Giese, Elane Guerreiro

    2017-01-01

    The genus Gnathostoma comprises 17 species, whose adult specimens are found in the stomach serosa of animals that consume raw fish; some species of the genus are zoonotic agents. The present study describes the presence of a nematode (Gnathostomatidae) parasitizing the digestive tract of Colomesus psittacus in the Ilha de Marajó in the eastern Brazilian Amazon. Thirty specimens of C. psittacus were collected in the municipality of Soure, Ilha de Marajó, state of Pará, Brazil, transported to the laboratory, necropsied and the helminths were collected and fixed. Of the 30 fish that were studied, 16.67% were parasitized with nematodes. The nematode larvae found encysted in the intestinal serosa have anterior region with two lips, each with a pair of papillae; a cephalic bulb armed with six rows of discontinuous spines; four cervical sacs; a claviform esophagus; cuticular striations along the body; a simple excretory pore; and a short tail ending in a mucron. These morphological structures are diagnostic characters of the genus Gnathostoma, whose adults parasitize the stomach of carnivorous mammals and, rarely, the stomach of fish. However, fish, amphibians, reptiles, and birds are intermediate hosts of the third-stage larvae (L3), and humans may act as accidental hosts.

  11. Evolution of GHF5 endoglucanase gene structure in plant-parasitic nematodes: no evidence for an early domain shuffling event

    Directory of Open Access Journals (Sweden)

    Gheysen Godelieve

    2008-11-01

    Full Text Available Abstract Background Endo-1,4-beta-glucanases or cellulases from the glycosyl hydrolase family 5 (GHF5 have been found in numerous bacteria and fungi, and recently also in higher eukaryotes, particularly in plant-parasitic nematodes (PPN. The origin of these genes has been attributed to horizontal gene transfer from bacteria, although there still is a lot of uncertainty about the origin and structure of the ancestral GHF5 PPN endoglucanase. It is not clear whether this ancestral endoglucanase consisted of the whole gene cassette, containing a catalytic domain and a carbohydrate-binding module (CBM, type 2 in PPN and bacteria or only of the catalytic domain while the CBM2 was retrieved by domain shuffling later in evolution. Previous studies on the evolution of these genes have focused primarily on data of sedentary nematodes, while in this study, extra data from migratory nematodes were included. Results Two new endoglucanases from the migratory nematodes Pratylenchus coffeae and Ditylenchus africanus were included in this study. The latter one is the first gene isolated from a PPN of a different superfamily (Sphaerularioidea; all previously known nematode endoglucanases belong to the superfamily Tylenchoidea (order Rhabditida. Phylogenetic analyses were conducted with the PPN GHF5 endoglucanases and homologous endoglucanases from bacterial and other eukaryotic lineages such as beetles, fungi and plants. No statistical incongruence between the phylogenetic trees deduced from the catalytic domain and the CBM2 was found, which could suggest that both domains have evolved together. Furthermore, based on gene structure data, we inferred a model for the evolution of the GHF5 endoglucanase gene structure in plant-parasitic nematodes. Our data confirm a close relationship between Pratylenchus spp. and the root knot nematodes, while some Radopholus similis endoglucanases are more similar to cyst nematode genes. Conclusion We conclude that the ancestral

  12. Estimated prevalence of nematode parasitism among pet cats in the United States.

    Science.gov (United States)

    De Santis, Andrea C; Raghavan, Malathi; Caldanaro, Richard J; Glickman, Nita W; Moore, George E; Lewis, Hugh B; Schantz, Peter M; Glickman, Lawrence T

    2006-03-15

    To estimate prevalences of roundworm, hookworm, and whipworm infections in pet cats in the United States and identify risk factors for parasitism. Retrospective period prevalence survey. 356,086 cats examined at 359 private veterinary hospitals during 2003. Electronic medical records were searched to identify cats for which fecal flotation tests had been performed and to determine proportions of test results positive for roundworms, hookworms, and whipworms. Potential risk factors for roundworm and hookworm infection were identified by means of multivariate logistic regression analysis. A total of 80,278 tests were performed on fecal samples from 66,819 cats. Calculated prevalences of roundworm, hookworm, and whipworm infection were 2.92%, 0.63%, and 0.031%, respectively. Age, reproductive status, breed, and season were significant risk factors for roundworm infection, with cats prevalences of roundworm and hookworm infection were found. Results suggest that prevalences of nematode infections among pet cats in the United States may be lower than previously suspected on the basis of prevalences reported among cats in humane shelters and those reported in more geographically focused studies.

  13. The genome and life-stage specific transcriptomes of Globodera pallida elucidate key aspects of plant parasitism by a cyst nematode

    KAUST Repository

    Cotton, James A

    2014-03-03

    Background: Globodera pallida is a devastating pathogen of potato crops, making it one of the most economically important plant parasitic nematodes. It is also an important model for the biology of cyst nematodes. Cyst nematodes and root-knot nematodes are the two most important plant parasitic nematode groups and together represent a global threat to food security. Results: We present the complete genome sequence of G. pallida, together with transcriptomic data from most of the nematode life cycle, particularly focusing on the life cycle stages involved in root invasion and establishment of the biotrophic feeding site. Despite the relatively close phylogenetic relationship with root-knot nematodes, we describe a very different gene family content between the two groups and in particular extensive differences in the repertoire of effectors, including an enormous expansion of the SPRY domain protein family in G. pallida, which includes the SPRYSEC family of effectors. This highlights the distinct biology of cyst nematodes compared to the root-knot nematodes that were, until now, the only sedentary plant parasitic nematodes for which genome information was available. We also present in-depth descriptions of the repertoires of other genes likely to be important in understanding the unique biology of cyst nematodes and of potential drug targets and other targets for their control. Conclusions: The data and analyses we present will be central in exploiting post-genomic approaches in the development of much-needed novel strategies for the control of G. pallida and related pathogens. 2014 Cotton et al.; licensee BioMed Central Ltd.

  14. Efficient in vitro RNA interference and immunofluorescence-based phenotype analysis in a human parasitic nematode, Brugia malayi

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    Landmann Frédéric

    2012-01-01

    Full Text Available Abstract Background RNA interference (RNAi is an efficient reverse genetics technique for investigating gene function in eukaryotes. The method has been widely used in model organisms, such as the free-living nematode Caenorhabditis elegans, where it has been deployed in genome-wide high throughput screens to identify genes involved in many cellular and developmental processes. However, RNAi techniques have not translated efficiently to animal parasitic nematodes that afflict humans, livestock and companion animals across the globe, creating a dependency on data tentatively inferred from C. elegans. Results We report improved and effective in vitro RNAi procedures we have developed using heterogeneous short interfering RNA (hsiRNA mixtures that when coupled with optimized immunostaining techniques yield detailed analysis of cytological defects in the human parasitic nematode, Brugia malayi. The cellular disorganization observed in B. malayi embryos following RNAi targeting the genes encoding γ-tubulin, and the polarity determinant protein, PAR-1, faithfully phenocopy the known defects associated with gene silencing of their C. elegans orthologs. Targeting the B. malayi cell junction protein, AJM-1 gave a similar but more severe phenotype than that observed in C. elegans. Cellular phenotypes induced by our in vitro RNAi procedure can be observed by immunofluorescence in as little as one week. Conclusions We observed cytological defects following RNAi targeting all seven B. malayi transcripts tested and the phenotypes mirror those documented for orthologous genes in the model organism C. elegans. This highlights the reliability, effectiveness and specificity of our RNAi and immunostaining procedures. We anticipate that these techniques will be widely applicable to other important animal parasitic nematodes, which have hitherto been mostly refractory to such genetic analysis.

  15. Endosymbiont-based immunity in Drosophila melanogaster against parasitic nematode infection.

    Science.gov (United States)

    Yadav, Shruti; Frazer, Joanna; Banga, Ashima; Pruitt, Katherine; Harsh, Sneh; Jaenike, John; Eleftherianos, Ioannis

    2018-01-01

    Associations between endosymbiotic bacteria and their hosts represent a complex ecosystem within organisms ranging from humans to protozoa. Drosophila species are known to naturally harbor Wolbachia and Spiroplasma endosymbionts, which play a protective role against certain microbial infections. Here, we investigated whether the presence or absence of endosymbionts affects the immune response of Drosophila melanogaster larvae to infection by Steinernema carpocapsae nematodes carrying or lacking their mutualistic Gram-negative bacteria Xenorhabdus nematophila (symbiotic or axenic nematodes, respectively). We find that the presence of Wolbachia alone or together with Spiroplasma promotes the survival of larvae in response to infection with S. carpocapsae symbiotic nematodes, but not against axenic nematodes. We also find that Wolbachia numbers are reduced in Spiroplasma-free larvae infected with axenic compared to symbiotic nematodes, and they are also reduced in Spiroplasma-containing compared to Spiroplasma-free larvae infected with axenic nematodes. We further show that S. carpocapsae axenic nematode infection induces the Toll pathway in the absence of Wolbachia, and that symbiotic nematode infection leads to increased phenoloxidase activity in D. melanogaster larvae devoid of endosymbionts. Finally, infection with either type of nematode alters the metabolic status and the fat body lipid droplet size in D. melanogaster larvae containing only Wolbachia or both endosymbionts. Our results suggest an interaction between Wolbachia endosymbionts with the immune response of D. melanogaster against infection with the entomopathogenic nematodes S. carpocapsae. Results from this study indicate a complex interplay between insect hosts, endosymbiotic microbes and pathogenic organisms.

  16. The Transcriptomes of Xiphinema index and Longidorus elongatus Suggest Independent Acquisition of Some Plant Parasitism Genes by Horizontal Gene Transfer in Early-Branching Nematodes

    NARCIS (Netherlands)

    Danchin, Etienne G.J.; Perfus-Barbeoch, Laetitia; Rancurel, Corinne; Thorpe, Peter; Rocha, Da Martine; Bajew, Simon; Neilson, Roy; Sokolova, Elena; Silva, Da Corinne; Guy, Julie; Labadie, Karine; Esmenjaud, Daniel; Helder, Hans; Jones, John T.; Eves-van den Akker, Sebastian

    2017-01-01

    Nematodes have evolved the ability to parasitize plants on at least four independent occasions, with plant parasites present in Clades 1, 2, 10 and 12 of the phylum. In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been

  17. Histopathology of Andean Potato (Solanum tuberosum Andigenum group) varieties parasitized by the false root-knot nematode, Nacobbus aberrans.

    Science.gov (United States)

    Tordable, M Del C; Andrade, A J; Doucet, M E; Lax, P

    2018-02-01

    Landraces of the Solanum tuberosum Andigenum group are abundant and diverse. They are a valuable genetic resource possessing resistance to pests, diseases, and environmental stresses. In the Andean region, populations of the false root-knot nematode Nacobbus aberrans became specialized to infect native potatoes, being one of the major limiting factors affecting this crop. A better understanding of the host plant-parasite interactions is important in order to select tolerant or resistant plants to be included in management programs. Despite the close of association of N. aberrans with potato, and the great diversity of the S. tuberosum Andigenum group, few histopathological studies have been conducted. The aim of this work was to analyze histological alterations induced by different Argentine populations of the nematode in naturally infested roots of four Andean potato varieties (Collareja, Negra Imilla, Ojo de Señorita and Colorada). All the varieties showed hyperplastic tissue in the central zone of galls, where syncytia developed in close association with the nematode female. Syncytia were composed of modified hyperplastic tissue and parenchyma xylem cells. The results showed differences among varieties in their response to nematode populations, with Ojo de Señorita and Negra Imilla being the most susceptible ones. This study is the first describing histopathological alterations induced by N. aberrans in susceptible Andean potato landraces.

  18. Histopathology of Andean Potato (Solanum tuberosum Andigenum group varieties parasitized by the false root-knot nematode, Nacobbus aberrans

    Directory of Open Access Journals (Sweden)

    M. del C. Tordable

    2018-02-01

    Full Text Available Abstract Landraces of the Solanum tuberosum Andigenum group are abundant and diverse. They are a valuable genetic resource possessing resistance to pests, diseases, and environmental stresses. In the Andean region, populations of the false root-knot nematode Nacobbus aberrans became specialized to infect native potatoes, being one of the major limiting factors affecting this crop. A better understanding of the host plant-parasite interactions is important in order to select tolerant or resistant plants to be included in management programs. Despite the close of association of N. aberrans with potato, and the great diversity of the S. tuberosum Andigenum group, few histopathological studies have been conducted. The aim of this work was to analyze histological alterations induced by different Argentine populations of the nematode in naturally infested roots of four Andean potato varieties (Collareja, Negra Imilla, Ojo de Señorita and Colorada. All the varieties showed hyperplastic tissue in the central zone of galls, where syncytia developed in close association with the nematode female. Syncytia were composed of modified hyperplastic tissue and parenchyma xylem cells. The results showed differences among varieties in their response to nematode populations, with Ojo de Señorita and Negra Imilla being the most susceptible ones. This study is the first describing histopathological alterations induced by N. aberrans in susceptible Andean potato landraces.

  19. Gene Silencing and Sex Determination by Programmed DNA Elimination in Parasitic Nematodes

    Science.gov (United States)

    Streit, Adrian; Wang, Jianbin; Kang, Yuanyuan; Davis, Richard E.

    2016-01-01

    Maintenance of genome integrity is essential. However, programmed DNA elimination removes specific DNA sequences from the genome during early development. DNA elimination occurs in unicellular ciliates and diverse metazoa ranging from nematodes to vertebrates. Two distinct groups of nematodes use DNA elimination to silence germline-expressed genes in the soma (ascarids) or for sex determination (Strongyloides spp.). Data suggest that DNA elimination likely evolved independently in these nematodes. Recent studies indicate that differential CENP-A deposition within chromosomes determines which sequences are retained and lost during Ascaris DNA elimination. Additional studies are needed to determine the distribution, functions, and mechanisms of DNA elimination in nematodes. PMID:27315434

  20. Variability in the fecal egg count and the parasitic burden of hair sheep after grazing in nematode infected paddocks

    Directory of Open Access Journals (Sweden)

    Roberto González-Garduño

    2013-04-01

    Full Text Available This study aimed to evaluate the variability in the fecal egg count (FEC and the parasitic burden of naive hair sheep after grazing in nematode infected paddocks. The research was carried out in Tabasco, Mexico, during two periods (August and December. In each period 32 lambs were grazed for one month on African star grass (Cynodon plectostachyus contaminated with gastrointestinal parasitic nematodes. FEC, packed cell volume (PCV and body weight (BW were recorded. Gastrointestinal worms were recovered at necropsy. Data were analyzed with the MIXED procedure of SAS using a model of repeated measurements over time. A higher number of Haemonchus contortus worms was found in December (2814±838 than in August (1166±305. The opposite occurred with Cooperia curticei (2167±393 and 3638±441, respectively. The FEC and correlation coefficient in respect to the worm burden were higher in December (6516 ± 1599, r=0.83, respectively than in August (4364±771, r=0.44, respectively. A high variability in resistance-susceptibility to gastrointestinal nematodes (GIN occurred in Katahdin × Pelibuey lambs after grazing.

  1. Philippine Survey of Nematode Parasite Infection and Load in the Giant African Snail Achatina fulica indicate Angiostrongylus cantonensis infection in Mindanao

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    Daisy May A. Constantino-Santos

    2014-12-01

    Full Text Available Achatina fulica is a ubiquitous land snail commonly found throughout the Philippines. As a generalist feeder and being able to survive in a wide range of habitat types and conditions, the snail can easily establish itself in a new area after introduction. It also acts as host to a variety of parasites, including nematodes, which may accidentally infect humans. In this study, A. fulica individuals from 13 areas in the Philippines were sampled and analyzed for nematode infection rate and load. Of the 393 individuals sampled, 80 (20% were found to be infected, with 5049 nematodes isolated. The infection rates and parasite load were highly variable. Overall, the parasite load ranges from 1 to 867 per snail. Representative nematodes from A. fulica from Plaridel (n=8 and Davao City (n=26 in Mindanao were subjected to DNA extraction, PCR amplification, and sequencing of the SSU rRNA gene, which is the universal barcode for nematodes. Sequences successfully matched with the dog lungworm Oslerus osleri for the Plaridel nematodes and the rat lungworm Angiostrongylus cantonensis for the Davao City nematodes, respectively. The latter is known to infect humans and can cause eosinophilic meningoencephalitis. This study presents the first report of A. cantonensis in A. fulica from Mindanao and raises a public health concern.

  2. Species Composition and Structure of the Communities of Plant-Parasitic and Free-Living Soil Nematodes in the Greenhouses of Botanical Gardens of Ukraine

    Directory of Open Access Journals (Sweden)

    Gubin A.I.

    2014-07-01

    Full Text Available Species Composition and Structure of the Communities of Plant-Parasitic and Free-Living Soil Nematodes in the Greenhouses of Botanical Gardens of Ukraine. Gubin, A. I., Sigareva, D. D. — In greenhouses of botanical gardens of Ukraine 81 species of nematodes were found. The richest by the number of species was Tylenchida order that was presented by 25 species (31 % of species composition. The dominant group of nematodes was plant-parasitic (most frequent was Rotylenchus robustus (de Man, 1876 Filipjev, 1936 and Meloidogyne incognita (Kofoid et White, 1919 Chitwood, 1949. The group of saprobiotic nematodes, which was presented by 52 species (64 %, appeared to be the richest by the number of species. It is shown, that formation of nematode communities in greenhouses of botanical gardens was caused by the interaction of many related factors, crucial of which is the composition of plant collections. The structure of communities is quite constant and almost independent of the quantity of nematodes species. Plant-parasitic species dominate by the number and frequency of detection, and represent a kind of a core of nematode communities.

  3. The effect of a nematode parasite on feeding and dung-burying behavior of an ecosystem engineer.

    Science.gov (United States)

    Boze, Broox G V; Moore, Janice

    2014-07-01

    Dung beetles (genus Phanaeus) consume feces in both their larval and adults forms and because of their unique dietary niche, and behaviors associated with the burial of feces, are considered ecosystem engineers. In addition, because these insects subsist on a diet composed exclusively of feces, it is likely they encounter parasitic propagules more frequently than other animals do. Parasites often alter their host's behavior, so we set out to test whether Physocephalus sexalatus (a cosmopolitan nematode parasite of ungulates) does so in ways that affect the dung beetle's role as an ecosystem engineer and/or its predator-prey relationships (transmission of the parasite). Classic tests of anti-predator behavior did not reveal behavioral differences based on the beetles' infection status. However, this parasite did alter the beetles' behaviors in ways that could be critical for its role in fecal processing and therefore ecosystem engineering. Infected beetles exhibited anorexic behavior and consumed only half the amount of feces ingested by similar uninfected beetles. Infected beetles also buried less feces and did so in tunnels that were significantly shorter than those created by uninfected beetles. Fecal burial is naturally beneficial because it aerates the soil, incorporates nitrogenous compounds, and increases the flow of water thereby making soil and pastureland more productive. We showed that the nematode parasite P. sexalatus itself becomes an ecosystem engineer as it modifies the behavior of its already influential intermediate host. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  4. Copromicroscopic and molecular assays for the detection of cancer-causing parasitic nematode Spirocerca lupi.

    Science.gov (United States)

    Traversa, Donato; Avolio, Stefania; Modrý, David; Otranto, Domenico; Iorio, Raffaella; Aroch, Itamar; Cringoli, Giuseppe; Milillo, Piermarino; Albrechtová, Katka; Mihalca, Andrei D; Lavy, Eran

    2008-10-20

    Spirocerca lupi (Nematoda, Spirurida) is a life-threatening parasitic nematode of dogs that is presently emerging in several countries. Nonetheless, canine spirocercosis is neglected and underestimated, mainly due to diagnostic limitations inherent to clinico-pathologic, diagnostic imaging and laboratory methodologies. Given the significant benefit of improved diagnosis, the present work evaluated the reliability of a recently described copromicroscopic approach, the FLOTAC technique, as well as a PCR-based assay with that of traditional coproscopic techniques to diagnose S. lupi infection. Ninety-four faecal field samples were collected from two endemic areas (i.e. 29 and 65 from Kenya and Israel, respectively) and processed using different coproscopic examination techniques. In particular, set I (Kenyan samples) comprised the modified flotation with Sheather's sugar solution and merthiolate-iodine-formalin technique, while set II (Israeli samples) comprised a flotation technique with zinc sulphate solution, a modified sugar flotation procedure and the FLOTAC method. All samples were also subjected to a semi-nested PCR protocol specific for a region internal to the mitochondrial cytochrome c oxidase subunit 1 gene of S. lupi. The coproscopic examinations showed low sensitivity and high variability, demonstrating the unreliability of the conventional methods for detecting S. lupi eggs. Nonetheless, the FLOTAC technique scored the highest number of positives and significantly higher number of S. lupi eggs per microscopic field compared to the other coproscopic methods. Additionally, of the coproscopically negative samples, 9 (45%) Kenyan and 21 (38.2%) Israeli samples scored molecularly positive using the PCR-based approach. The potential implications and perspectives for canine spirocercosis of these coproscopic and molecular diagnostic methodologies evaluated herein are discussed.

  5. Successes and failures in the use of parasitic nematodes for pest control

    NARCIS (Netherlands)

    Georgis, R.; Koppenhöfer, A.M.; Lacey, L.A.; Bélair, G.; Duncan, L.W.; Grewal, P.S.; Samish, M.; Tan, L.; Torr, P.; Tol, van R.W.H.M.

    2006-01-01

    Advances in mass-production and formulation technology of entomopathogenic nematodes, the discovery of numerous isolates/strains and the desirability of reducing pesticide usage have resulted in a surge of scientific and commercial interest in these nematodes. The lessons learned from earlier

  6. Conservation of a microRNA cluster in parasitic nematodes and profiling of miRNAs in excretory-secretory products and microvesicles of Haemonchus contortus.

    Directory of Open Access Journals (Sweden)

    Henry Y Gu

    2017-11-01

    Full Text Available microRNAs are small non-coding RNAs that are important regulators of gene expression in a range of animals, including nematodes. We have analysed a cluster of four miRNAs from the pathogenic nematode species Haemonchus contortus that are closely linked in the genome. We find that the cluster is conserved only in clade V parasitic nematodes and in some ascarids, but not in other clade III species nor in clade V free-living nematodes. Members of the cluster are present in parasite excretory-secretory products and can be detected in the abomasum and draining lymph nodes of infected sheep, indicating their release in vitro and in vivo. As observed for other parasitic nematodes, H. contortus adult worms release extracellular vesicles (EV. Small RNA libraries were prepared from vesicle-enriched and vesicle-depleted supernatants from both adult worms and L4 stage larvae. Comparison of the miRNA species in the different fractions indicated that specific miRNAs are packaged within vesicles, while others are more abundant in vesicle-depleted supernatant. Hierarchical clustering analysis indicated that the gut is the likely source of vesicle-associated miRNAs in the L4 stage, but not in the adult worm. These findings add to the growing body of work demonstrating that miRNAs released from parasitic helminths may play an important role in host-parasite interactions.

  7. Cathepsin B Cysteine Proteinase is Essential for the Development and Pathogenesis of the Plant Parasitic Nematode Radopholus similis

    Science.gov (United States)

    Li, Yu; Wang, Ke; Xie, Hui; Wang, Dong-Wei; Xu, Chun-Ling; Huang, Xin; Wu, Wen-Jia; Li, Dan-Lei

    2015-01-01

    Radopholus similis is an important plant parasitic nematode which severely harms many crops. Cathepsin B is present in a wide variety of organisms, and plays an important role in many parasites. Understanding cathepsin B of R. similis would allow us to find new targets and approaches for its control. In this study, we found that Rs-cb-1 mRNA was expressed in esophageal glands, intestines and gonads of females, testes of males, juveniles and eggs in R. similis. Rs-cb-1 expression was the highest in females, followed by juveniles and eggs, and was the lowest in males. The maximal enzyme activity of Rs-CB-1 was detected at pH 6.0 and 40 °C. Silencing of Rs-cb-1 using in vitro RNAi (Soaking with dsRNA in vitro) not only significantly inhibited the development and hatching of R. similis, but also greatly reduced its pathogenicity. Using in planta RNAi, we confirmed that Rs-cb-1 expression in nematodes were significantly suppressed and the resistance to R. similis was significantly improved in T2 generation transgenic tobacco plants expressing Rs-cb-1 dsRNA. The genetic effects of in planta RNAi-induced gene silencing could be maintained in the absence of dsRNA for at least two generations before being lost, which was not the case for the effects induced by in vitro RNAi. Overall, our results first indicate that Rs-cb-1 plays key roles in the development, hatching and pathogenesis of R. similis, and that in planta RNAi is an effective tool in studying gene function and genetic engineering of plant resistance to migratory plant parasitic nematodes. PMID:26221074

  8. Hystrignathus dearmasi sp. n. (Oxyurida, Hystrignathidae), first record of a nematode parasitizing a Panamanian Passalidae (Insecta, Coleoptera)

    Science.gov (United States)

    Morffe, Jans; García, Nayla

    2010-01-01

    Abstract Hystrignathus dearmasi sp. n. (Oxyurida: Hystrignathidae) is described from an unidentified passalid beetle (Coleoptera: Passalidae) from Panama. It resembles Hystrignathus cobbi Travassos & Kloss, 1957 from Brazil, by having a similar form of the cephalic end, extension of cervical spines and absence of lateral alae. It differs from the latter species by having the body shorter, the oesophagus and tail comparatively larger, the vulva situated more posterior and the eggs ridged. This species constitutes the first record of a nematode parasitizing a Panamanian passalid. PMID:21594186

  9. In-vitro predatory activity of nematophagous fungi from Costa Rica with potential use for controlling sheep and goat parasitic nematodes

    OpenAIRE

    Natalia Soto-Barrientos; Jaqueline de Oliveira; Rommel Vega-Obando; Danilo Montero-Caballero; Bernardo Vargas; Jorge Hernández-Gamboa; Claudio Orozco-Solano

    2011-01-01

    In tropical and subtropical regions of the world, parasitic diseases are a main cause of losses in livestock productivity. The increased acquired resistence to anthelmintics by gastrointestinal nematodes, requires biological control be considered as a potential feasible and effective alternative. The most effective natural soil enemies of nematodes are nematophagous fungi. In order to collect and identify predator nematophagous fungi (PNF), samples were obtained from 51 farms distributed thro...

  10. Multichannel microfluidic chip for rapid and reliable trapping and imaging plant-parasitic nematodes

    Science.gov (United States)

    Amrit, Ratthasart; Sripumkhai, Witsaroot; Porntheeraphat, Supanit; Jeamsaksiri, Wutthinan; Tangchitsomkid, Nuchanart; Sutapun, Boonsong

    2013-05-01

    Faster and reliable testing technique to count and identify nematode species resided in plant roots is therefore essential for export control and certification. This work proposes utilizing a multichannel microfluidic chip with an integrated flow-through microfilter to retain the nematodes in a trapping chamber. When trapped, it is rather simple and convenient to capture images of the nematodes and later identify their species by a trained technician. Multiple samples can be tested in parallel using the proposed microfluidic chip therefore increasing number of samples tested per day.

  11. The Transcriptomes of Xiphinema index and Longidorus elongatus Suggest Independent Acquisition of Some Plant Parasitism Genes by Horizontal Gene Transfer in Early-Branching Nematodes.

    Science.gov (United States)

    Danchin, Etienne G J; Perfus-Barbeoch, Laetitia; Rancurel, Corinne; Thorpe, Peter; Da Rocha, Martine; Bajew, Simon; Neilson, Roy; Guzeeva, Elena Sokolova; Da Silva, Corinne; Guy, Julie; Labadie, Karine; Esmenjaud, Daniel; Helder, Johannes; Jones, John T; den Akker, Sebastian Eves-van

    2017-10-23

    Nematodes have evolved the ability to parasitize plants on at least four independent occasions, with plant parasites present in Clades 1, 2, 10 and 12 of the phylum. In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been implicated in the evolution of plant parasitism. We have used ribonucleic acid sequencing (RNAseq) to generate reference transcriptomes for two economically important nematode species, Xiphinema index and Longidorus elongatus , representative of two genera within the early-branching Clade 2 of the phylum Nematoda. We used a transcriptome-wide analysis to identify putative horizontal gene transfer events. This represents the first in-depth transcriptome analysis from any plant-parasitic nematode of this clade. For each species, we assembled ~30 million Illumina reads into a reference transcriptome. We identified 62 and 104 transcripts, from X. index and L. elongatus , respectively, that were putatively acquired via horizontal gene transfer. By cross-referencing horizontal gene transfer prediction with a phylum-wide analysis of Pfam domains, we identified Clade 2-specific events. Of these, a GH12 cellulase from X. index was analysed phylogenetically and biochemically, revealing a likely bacterial origin and canonical enzymatic function. Horizontal gene transfer was previously shown to be a phenomenon that has contributed to the evolution of plant parasitism among nematodes. Our findings underline the importance and the extensiveness of this phenomenon in the evolution of plant-parasitic life styles in this speciose and widespread animal phylum.

  12. Anatomo-pathological aspects of parasitism by nematodes of the superfamily Metastrongyloidea in wild crab-eating fox (Cerdocyon thous in Midwestern Brazil

    Directory of Open Access Journals (Sweden)

    Jair Alves Ferreira Júnior

    Full Text Available ABSTRACT: Nematodes of the superfamily Metastrongyloidea affect the respiratory, cardiovascular, and nervous systems of domestic carnivores and are uncommonly detected in wild animals. This report describes the lesions associated with pulmonary parasitism by nematodes of the superfamily Metastrongyloidea in a wild crab-eating fox ( Cerdocyon thous in the Federal District, Brazil. Grossly, there was pulmonary hyperemia, edema, and emphysema. Microscopically, there was granulomatous arteritis associated with intravascular metastrongylid. The anatomical location, characteristic lesion, and histological features of the parasite suggested that the nematode involved in this case is Angiostrongylus vasorum . This worm is frequently reported parasitizing pulmonary arteries of domestic canids but is uncommonly described in wild canids in Midwestern Brazil.

  13. Control of nematode parasites with agents acting on neuro-musculature systems: lessons for neuropeptide ligand discovery.

    Science.gov (United States)

    Martin, Richard J; Robertson, Alan P

    2010-01-01

    There are a number of reasons why the development of novel anthelmintics is very necessary. In domestic animals, parasites cause serious loss of production and are a welfare concern. The control of these parasites requires changes in management practices to reduce the spread of infection and the use of therapeutic agents to treat affected animals. The development of vaccines against parasites is desirable but their development so far has been very limited. One notable exception is the vaccination of calves against infection by Dictyocaulus viviparous (lungworm) which has proved to be very effective. In domestic animals, the total market for anti-parasitic agents (both ecto- and endo-parasites) is in excess of a billion U.S. dollars. In humans there are serious problems ofmorbidity and mortality associated with parasite infections. 1.6 billion People throughout the world are infected with ascariasis (Fig. 1A) and/or hookworm. Approximately one-third of the world's population is suffering from the effects of intestinal nematode parasites, causing low growth-rates in infants, ill-thrift, diarrhea and in 2% of cases, loss of life. Despite the huge number of affected individuals, the market for anti-parasitic drugs for humans is not big enough to foster the development of anthelmintics because most infestations that occur are in undeveloped countries that lack the ability to pay for the development of these drugs. The major economic motivator then, is for the development of animal anthelmintics. In both domestic animals and now in humans, there is now a level of resistance to the available anthelmintic compounds. The resistance is either: constitutive, where a given species of parasite has never been sensitive to the compound; or acquired, where the resistance has developed through Darwinian selection fostered by the continued exposure to the anti-parasitic drugs. The continued use of all anthelmintics has and will, continue to increase the level of resistance. Cure

  14. Pelecitus helicinus Railliet & Henry, 1910 (Filarioidea, Dirofilariinae and Other Nematode Parasites of Brazilian Birds

    Directory of Open Access Journals (Sweden)

    Oniki Yoshika

    2002-01-01

    Full Text Available We report Pelecitus helicinus Railliet & Henry, 1910 from 13 species of birds of 2 orders and 7 families, collected from the states of São Paulo and Mato Grosso, Brazil. All 13 constitute new host records for this nematode. In addition, we report the first record of Aprocta golvani Diaz-Ungria, 1963 from Brazil and Monasa nigrifrons (Bucconidae, as well as a number of other nematode records from Neotropical birds.

  15. Transcriptome Sequencing Analysis and Functional Identification of Sex Differentiation Genes from the Mosquito Parasitic Nematode, Romanomermis wuchangensis.

    Directory of Open Access Journals (Sweden)

    Mingyue Duan

    Full Text Available Mosquito-transmitted diseases like malaria and dengue fever are global problem and an estimated 50-100 million of dengue or dengue hemorrhagic fever cases are reported worldwide every year. The mermithid nematode Romanomermis wuchangensis has been successfully used as an ecosystem-friendly biocontrol agent for mosquito prevention in laboratory studies. However, this nematode can not undergo sex differentiation in vitro culture, which has seriously affected their application of biocontrol in the field. In this study, based on transcriptome sequencing analysis of R. wuchangensis, Rwucmab-3, Rwuclaf-1 and Rwuctra-2 were cloned and used to investigate molecular regulatory function of sex differentiation. qRT-PCR results demonstrated that the expression level of Rwucmab-3 between male and female displayed obvious difference on the 3rd day of parasitic stage, which was earlier than Rwuclaf-1 and Rwuctra-2, highlighting sex differentiation process may start on the 3rd day of parasitic stage. Besides, FITC was used as a marker to test dsRNA uptake efficiency of R. wuchangensis, which fluorescence intensity increased with FITC concentration after 16 h incubation, indicating this nematode can successfully ingest soaking solution via its cuticle. RNAi results revealed the sex ratio of R. wuchangensis from RNAi treated groups soaked in dsRNA of Rwucmab-3 was significantly higher than gfp dsRNA treated groups and control groups, highlighting RNAi of Rwumab-3 may hinder the development of male nematodes. These results suggest that Rwucmab-3 mainly involves in the initiation of sex differentiation and the development of male sexual dimorphism. Rwuclaf-1 and Rwuctra-2 may play vital role in nematode reproductive and developmental system. In conclusion, transcript sequences presented in this study could provide more bioinformatics resources for future studies on gene cloning and other molecular regulatory mechanism in R. wuchangensis. Moreover, identification

  16. Needles in the EST haystack: large-scale identification and analysis of excretory-secretory (ES proteins in parasitic nematodes using expressed sequence tags (ESTs.

    Directory of Open Access Journals (Sweden)

    Shivashankar H Nagaraj

    2008-09-01

    Full Text Available Parasitic nematodes of humans, other animals and plants continue to impose a significant public health and economic burden worldwide, due to the diseases they cause. Promising antiparasitic drug and vaccine candidates have been discovered from excreted or secreted (ES proteins released from the parasite and exposed to the immune system of the host. Mining the entire expressed sequence tag (EST data available from parasitic nematodes represents an approach to discover such ES targets.In this study, we predicted, using EST2Secretome, a novel, high-throughput, computational workflow system, 4,710 ES proteins from 452,134 ESTs derived from 39 different species of nematodes, parasitic in animals (including humans or plants. In total, 2,632, 786, and 1,292 ES proteins were predicted for animal-, human-, and plant-parasitic nematodes. Subsequently, we systematically analysed ES proteins using computational methods. Of these 4,710 proteins, 2,490 (52.8% had orthologues in Caenorhabditis elegans, whereas 621 (13.8% appeared to be novel, currently having no significant match to any molecule available in public databases. Of the C. elegans homologues, 267 had strong "loss-of-function" phenotypes by RNA interference (RNAi in this nematode. We could functionally classify 1,948 (41.3% sequences using the Gene Ontology (GO terms, establish pathway associations for 573 (12.2% sequences using Kyoto Encyclopaedia of Genes and Genomes (KEGG, and identify protein interaction partners for 1,774 (37.6% molecules. We also mapped 758 (16.1% proteins to protein domains including the nematode-specific protein family "transthyretin-like" and "chromadorea ALT," considered as vaccine candidates against filariasis in humans.We report the large-scale analysis of ES proteins inferred from EST data for a range of parasitic nematodes. This set of ES proteins provides an inventory of known and novel members of ES proteins as a foundation for studies focused on understanding the

  17. Needles in the EST Haystack: Large-Scale Identification and Analysis of Excretory-Secretory (ES) Proteins in Parasitic Nematodes Using Expressed Sequence Tags (ESTs)

    Science.gov (United States)

    Nagaraj, Shivashankar H.; Gasser, Robin B.; Ranganathan, Shoba

    2008-01-01

    Background Parasitic nematodes of humans, other animals and plants continue to impose a significant public health and economic burden worldwide, due to the diseases they cause. Promising antiparasitic drug and vaccine candidates have been discovered from excreted or secreted (ES) proteins released from the parasite and exposed to the immune system of the host. Mining the entire expressed sequence tag (EST) data available from parasitic nematodes represents an approach to discover such ES targets. Methods and Findings In this study, we predicted, using EST2Secretome, a novel, high-throughput, computational workflow system, 4,710 ES proteins from 452,134 ESTs derived from 39 different species of nematodes, parasitic in animals (including humans) or plants. In total, 2,632, 786, and 1,292 ES proteins were predicted for animal-, human-, and plant-parasitic nematodes. Subsequently, we systematically analysed ES proteins using computational methods. Of these 4,710 proteins, 2,490 (52.8%) had orthologues in Caenorhabditis elegans, whereas 621 (13.8%) appeared to be novel, currently having no significant match to any molecule available in public databases. Of the C. elegans homologues, 267 had strong “loss-of-function” phenotypes by RNA interference (RNAi) in this nematode. We could functionally classify 1,948 (41.3%) sequences using the Gene Ontology (GO) terms, establish pathway associations for 573 (12.2%) sequences using Kyoto Encyclopaedia of Genes and Genomes (KEGG), and identify protein interaction partners for 1,774 (37.6%) molecules. We also mapped 758 (16.1%) proteins to protein domains including the nematode-specific protein family “transthyretin-like” and “chromadorea ALT,” considered as vaccine candidates against filariasis in humans. Conclusions We report the large-scale analysis of ES proteins inferred from EST data for a range of parasitic nematodes. This set of ES proteins provides an inventory of known and novel members of ES proteins as a

  18. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia.

    Science.gov (United States)

    Sissay, Menkir M; Uggla, Arvid; Waller, Peter J

    2007-10-01

    A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger Oesopha-gostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the

  19. The Complex Cell Wall Composition of Syncytia Induced by Plant Parasitic Cyst Nematodes Reflects Both Function and Host Plant

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    Li Zhang

    2017-06-01

    Full Text Available Plant–parasitic cyst nematodes induce the formation of specialized feeding structures, syncytia, within their host roots. These unique plant organs serve as the sole nutrient resource for development and reproduction throughout the biotrophic interaction. The multinucleate syncytium, which arises through local dissolution of cell walls and protoplast fusion of multiple adjacent cells, has dense cytoplasm containing numerous organelles, surrounded by thickened outer cell walls that must withstand high turgor pressure. However, little is known about how the constituents of the syncytial cell wall and their conformation support its role during nematode parasitism. We used a set of monoclonal antibodies, targeted to a range of plant cell wall components, to reveal the microstructures of syncytial cell walls induced by four of the most economically important cyst nematode species, Globodera pallida, Heterodera glycines, Heterodera avenae and Heterodera filipjevi, in their respective potato, soybean, and spring wheat host roots. In situ fluorescence analysis revealed highly similar cell wall composition of syncytia induced by G. pallida and H. glycines. Both consisted of abundant xyloglucan, methyl-esterified homogalacturonan and pectic arabinan. In contrast, the walls of syncytia induced in wheat roots by H. avenae and H. filipjevi contain little xyloglucan but are rich in feruloylated xylan and arabinan residues, with variable levels of mixed-linkage glucan. The overall chemical composition of syncytial cell walls reflected the general features of root cell walls of the different host plants. We relate specific components of syncytial cell walls, such as abundant arabinan, methyl-esterification status of pectic homogalacturonan and feruloylation of xylan, to their potential roles in forming a network to support both the strength and flexibility required for syncytium function.

  20. Anti-parasitic effects of plant secondary metabolites on swine nematodes

    OpenAIRE

    Williams, A.R.; Pena-Espinoza, Miguel Angel; Fryganas, Christos; Ropiak, H.M.; Ramsay, Aina; Mueller-Harvey, I.; Thamsborg, S. M.

    2014-01-01

    Organic production presents challenges to animal health and productivity. In organic pig production, animals must have access to outdoor pastures which increases exposure to gastrointestinal parasites. Moreover, the routine use of synthetic anti-parasitic drugs is not allowed. Thus, novel parasite-control options are required. We present results from a comprehensive in vitro screen of plant secondary metabolites (PSM) from diverse plant sources on the economically important pig parasites Asca...

  1. Detection of parasitic nematodes in some fresh water fishes in khazir river in Ninevah governorate

    Directory of Open Access Journals (Sweden)

    A. F. Al-Taee

    2011-01-01

    Full Text Available A total of 200 freshwater fishes belonging to 7 species include, ALburnus capito, Barbus gryous, B. xanthopterus, Chondrostoma regius, Varcorhinus trutta and Liza abu, were collected form Al-Khazir river, Ninevah governorate (about 37 Km east of Mosul city, during the period from October 2006 to April 2007. All fishes were inspected for detection of nematode worms. The study reveals presence of 12 fishes infected with nematode worms, from the total fishes inspected with the prevalence of 6%. In this study also recorded 10 species of nematodes infecting freshwater fishes 3 genera of them recorded for the first time in Iraq are Raphidscaris sp., Anisakis sp. and Eustrongylides sp. in addition to the species Cucullanellus minutus, and Rhabdochona khazirensis as new species.

  2. In vitro anti-parasitic effects of sesquiterpene lactones from chicory against cattle nematodes

    DEFF Research Database (Denmark)

    Pena-Espinoza, Miguel Angel; Williams, A.; Boas, Ulrik

    of SL-rich extracts from 2 chicory cultivars on the viability of first-stage larvae (L1) of Ostertagia ostertagi, a pathogenic cattle nematode. Chicory Spadona and Puna II were grown at the same farm and leaves were sampled the same day. 1 g of freeze-dried leaves was extracted in methanol....../water. Resulting extracts were incubated with cellulase enzymes, recovered in ethyl acetate and purified by normal solid-phase extraction. Obtained extracts were dissolved in 100% dimethyl sulfoxide (DMSO). A calf infected with O. ostertagi served as donor of nematode eggs. Eggs were hatched and L1 obtained were...

  3. A preliminary survey on soil and plant parasitic nematodes of southern Goa, India

    Directory of Open Access Journals (Sweden)

    A.C.M. Lizanne

    2014-01-01

    Full Text Available A preliminary study was conducted to record the diversity of nematode fauna in Goa during 2011-2012. For the present study 50 samples were collected from five talukas of South Goa District, covering 25 villages and 20 landscapes. Permanent slides were prepared after extraction of nematodes using Cobb’s decanting and sieving method and modified Baermann’s funnel method. The study resulted in recording 52 species of seven orders. Dorylaimida was the dominant order both in number of species and genera while the least was Araeolaimida.

  4. Taxonomic status of Cyathostoma nematodes (Nematoda: Syngaminae parasitizing respiratory tracts of birds of prey and owls in Europe and North America: how many species are there?

    Directory of Open Access Journals (Sweden)

    Kanarek G.

    2016-03-01

    Full Text Available So far, the identity of Cyathostoma (Hovorkonema nematodes collected from respiratory tracts of birds of prey (Accipitriformes, Falconiformes and owls (Strigiformes in Europe and North America is extremely inconsistent. Our results, based on analyses of ITS-2 sequences suggest that the Cyathostoma (Hovorkonema nematodes found in the birds of prey and owls from Central Europe and North America probably belong to the same species, C. (Hovorkonema americana Chapin, 1925. We are convinced, that described in recent literature high ITS-2 divergence among C. (Hovorkonema nematodes collected from Europe, has occurred as a result of invalid synonimisation of some C. (Hovorkonema species. In our opinion C. (Hovorkonema americana (typically parasites of tracheae and air sacs of raptors and C. (Hovorkonema variegatum (Creplin, 1849 (typically parasites of tracheae of cranes and storks are valid molecular and morphologically distinct species.

  5. How anthropogenic changes may affect soil-borne parasite diversity? Plant-parasitic nematode communities associated with olive trees in Morocco as a case study.

    Science.gov (United States)

    Ali, Nadine; Tavoillot, Johannes; Besnard, Guillaume; Khadari, Bouchaib; Dmowska, Ewa; Winiszewska, Grażyna; Fossati-Gaschignard, Odile; Ater, Mohammed; Aït Hamza, Mohamed; El Mousadik, Abdelhamid; El Oualkadi, Aïcha; Moukhli, Abdelmajid; Essalouh, Laila; El Bakkali, Ahmed; Chapuis, Elodie; Mateille, Thierry

    2017-02-06

    Plant-parasitic nematodes (PPN) are major crop pests. On olive (Olea europaea), they significantly contribute to economic losses in the top-ten olive producing countries in the world especially in nurseries and under cropping intensification. The diversity and the structure of PPN communities respond to environmental and anthropogenic forces. The olive tree is a good host plant model to understand the impact of such forces on PPN diversity since it grows according to different modalities (wild, feral and cultivated olives). A wide soil survey was conducted in several olive-growing regions in Morocco. The taxonomical and the functional diversity as well as the structures of PPN communities were described and then compared between non-cultivated (wild and feral forms) and cultivated (traditional and high-density olive cultivation) olives. A high diversity of PPN with the detection of 117 species and 47 genera was revealed. Some taxa were recorded for the first time on olive trees worldwide and new species were also identified. Anthropogenic factors (wild vs cultivated conditions) strongly impacted the PPN diversity and the functional composition of communities because the species richness, the local diversity and the evenness of communities significantly decreased and the abundance of nematodes significantly increased in high-density conditions. Furthermore, these conditions exhibited many more obligate and colonizer PPN and less persister PPN compared to non-cultivated conditions. Taxonomical structures of communities were also impacted: genera such as Xiphinema spp. and Heterodera spp. were dominant in wild olive, whereas harmful taxa such as Meloidogyne spp. were especially enhanced in high-density orchards. Olive anthropogenic practices reduce the PPN diversity in communities and lead to changes of the community structures with the development of some damaging nematodes. The study underlined the PPN diversity as a relevant indicator to assess community

  6. Nematodes parasites de quatre especes de Carangoides (Osteichthyes: Carangidae) des eaux de Nouvelle-Caledonie, avec description de Philometra dispar n. sp. (Philometridae)

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Gey, D.; Justine, J.-L.

    2016-01-01

    Roč. 23, Sep 12 (2016), č. článku 40. ISSN 1252-607X R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:60077344 Keywords : parasitic nematode * new species * marine fish * New Caledonia * South Pacific Subject RIV: EG - Zoology Impact factor: 2.545, year: 2016

  7. Parasitic nematodes of the genus Syphacia Seurat, 1916 infecting Muridae in the British Isles, and the peculiar case of Syphacia frederici.

    NARCIS (Netherlands)

    Stewart, Alex; Lowe, Ann; Smales, Lesley; Bajer, Anna; Bradley, Jan; Dwużnik, Dorota; Franssen, Frits; Griffith, Jack; Stuart, Peter; Turner, Cyan; Zaleśny, Grzegorz; Behnke, Jerzy M

    2017-01-01

    Syphacia stroma (von Linstow, 1884) Morgan, 1932 and Syphacia frederici Roman, 1945 are oxyurid nematodes that parasitize two murid rodents, Apodemus sylvaticus and Apodemus flavicollis, on the European mainland. Only S. stroma has been recorded previously in Apodemus spp. from the British Isles.

  8. Redescription of Heliconema africanum (Linstow, 1899) n. comb. (Nematoda: Physalopteridae), a nematode parasite of freshwater eels (Anguilla spp.) in South Africa

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Taraschewski, H.; Weyl, O.L.F.

    2013-01-01

    Roč. 85, č. 3 (2013), s. 263-269 ISSN 0165-5752 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Parasitic nematode * Heliconema * South Africa Subject RIV: EA - Cell Biology Impact factor: 1.035, year: 2013

  9. Plant-Mediated Systemic Interactions Between Pathogens, Parasitic Nematodes, and Herbivores Above- and Belowground

    NARCIS (Netherlands)

    Biere, A.; Goverse, A.

    2016-01-01

    Plants are important mediators of interactions between aboveground (AG) and belowground (BG) pathogens, arthropod herbivores, and nematodes (phytophages). We highlight recent progress in our understanding of within- and cross-compartment plant responses to these groups of phytophages in terms of

  10. Plant-mediated systemic interactions between pathogens, parasitic nematodes, and herbivores above- and belowground

    NARCIS (Netherlands)

    Biere, A.; Goverse, Aska

    2016-01-01

    Plants are important mediators of interactions between aboveground (AG) and belowground (BG) pathogens, arthropod herbivores, and nematodes (phytophages). We highlight recent progress in our understanding of within and cross-compartment plant responses to these groups of phytophages in terms of

  11. Cloning and structural analysis of partial acetylcholine receptor subunit genes from the parasitic nematode Teladorsagia circumcincta

    NARCIS (Netherlands)

    Walker, J.; Hoekstra, R.; Roos, M. H.; Wiley, L. J.; Weiss, A. S.; Sangster, N. C.; Tait, A.

    2001-01-01

    Nematode nicotinic acetylcholine receptors (nAChRs) are the sites of action for the anthelmintic drug levamisole. Recent findings indicate that the molecular mechanism of levamisole resistance may involve changes in the number and/or functions of target nAChRs. Accordingly, we have used an RT-PCR

  12. Ecological aspects of nematode parasites of introduced salmonids from Valdivia river basin, Chile

    Directory of Open Access Journals (Sweden)

    Patricio Torres

    1991-03-01

    Full Text Available Between 1986 and 1987 fishes distributed among the following species introduced in Chile, and from different sectors of the Valdivia river basin (39º30' - 40º00', 73º30' - 71º45'W, were examined: 348 Salmo trutta, 242 Salmo gairdneri, 24 Cyprinus carpio and 52 Gambusia affinis holbrooki. The presence of Camallanus corderoi and Contracaecum sp. in S. gairdneri and of C. corderoi in S. trutta is recorded in Chile for the first time. Cyprinus carpio and G. a. holbrooki did not present infections by nematodes. The prevalence and mean intensity of the infections by nematodes presented significant differences among some sectors of the Valdivia river basin. In general, the prevalence and intensity of the infections by C. corderoi were greater than those by Contracaecum sp. The infections in S. gairdneri were higher than in S. trutta. The sex of the hosts had no influence on the prevalence and intensity of the infections by both nematodes. The length of the hosts did have an influence, except in the case of the infections by Contracaecum sp. in S, gairdneri. The infrapopulations of both nematode species showed over dispersion in most cases. The diet of the examined salmonids suggests that they would become infected principally throught the consuption of autochthonous fishes.

  13. Nematodes parasitic in fishes of cenotes (= sinkholes) of the Peninsula of Yucatan, Mexico. Part 1. Adults.

    Science.gov (United States)

    Moravec, F; Vivas-Rodríguez, C; Scholz, T; Vargas-Vázquez, J; Mendoza-Franco, E; González-Solís, D

    1995-01-01

    The present paper comprises a systematic survey of adult nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southeastern Mexico, in 1993-1994. Examinations of a total of 533 fishes (17 species) originating from 39 cenotes from the Mexican states of Yucatan and Quintana Roo revealed the presence of the following nine nematode species: Rhabdochona (Rhabdochona) kidderi, Procamallanus (Spirocamallanus) rebecae, P. (S.) neocaballeroi, Philometroides caudata, Hysterothylacium cenotue. Pseudocapillaria yucatanensis, Paracapillaria rhamdiae, P. teixerafreitasi and Capillostrongyloides sp. (only females). Four species (R. kidderi, P. rebecae, P. neocaballeroi and Capillostrongyloides sp.) are briefly described and illustrated and some problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Taxonomic changes include Procamallanus (Spirocamallanus) neocaballeroi (Caballero-Deloya. 1977) comb. n. and Procamallanus (Spirocamallanus) rebecae (Andrade-Salas, Pineda-López et García-Magaña, 1994) comb. n. The nematode fauna of fishes in cenotes of the Yucatan Peninsula shows its appurtenance to the Neotropical fauna with close affinities with that of fish nematodes from South America, but with a considerable degree of endemism.

  14. A Lymphatic dwelling filarioid nematode, Rumenfilaria andersoni (Filarioidea; Splendidofilariinae), is an emerging parasite in Finnish cervids

    Science.gov (United States)

    Background-Recent studies revealed expansion of filarioid nematodes into the northern Finland. In addition to Setaria tundra, unidentified and very abundant filarioids, representing Rumenfilaria andersoni, were found inhabiting the lymphatic vessels of reindeer. Our study explores the biology and d...

  15. Whence river blindness? The domestication of mammals and host-parasite co-evolution in the nematode genus Onchocerca.

    Science.gov (United States)

    Lefoulon, Emilie; Giannelli, Alessio; Makepeace, Benjamin L; Mutafchiev, Yasen; Townson, Simon; Uni, Shigehiko; Verocai, Guilherme G; Otranto, Domenico; Martin, Coralie

    2017-07-01

    The genus Onchocerca includes 34 described species and represents one of the largest genera of the filarial nematodes within the family Onchocercidae. Representative members of this genus are mainly parasites of ungulates, with some exceptions such as Onchocerca lupi and Onchocerca volvulus, infecting carnivores and/or humans. For a long time, the evolutionary relationships amongst onchocercids remained poorly studied, as the systematics of this genus was impaired by the high morphological variability of species included in the taxon. Although some molecular phylogenies were developed, these studies were mainly focused on bovine Onchocerca spp. and O. volvulus, including assessments of Wolbachia endosymbionts. In the present study, we analysed 13 Onchocerca spp. from a larger host spectrum using a panel of seven different genes. Analysis of the coxI marker supports its usefulness for the identification of species within the genus. The evolutionary history of the genus has been herein revised by multi-gene phylogenies, presenting three strongly supported clades of Onchocerca spp. Analyses of co-evolutionary scenarios between Onchocerca and their vertebrate hosts underline the effect of domestication on Onchocerca speciation. Our study indicates that a host switch event occurred between Bovidae, Canidae and humans. Cophylogenetic analyses between Onchocerca and the endosymbiotic bacterium Wolbachia indicate the strongest co-evolutionary pattern ever registered within the filarial nematodes. Finally, this dataset indicates that the clade composed by O. lupi, Onchocerca gutturosa, Onchocerca lienalis, Onchocerca ochengi and O. volvulus derived from recent speciation. Copyright © 2017. Published by Elsevier Ltd.

  16. [Gastrointestinal nematode parasitism in ewes and lambs raised in São Carlos, São Paulo].

    Science.gov (United States)

    Chagas, Ana Carolina De S; Oliveira, Márcia Cristina De S; Esteves, Sérgio N; De Oliveira, Henrique N; Giglioti, Rodrigo; Giglioti, Carolina; Carvalho, Camila De O; Ferrezini, Jenifer; Schiavone, Daniele C

    2008-09-01

    Gastrointestinal nematode infections were evaluated in Santa Inês crossbreed sheep (Santa Inês predominance) in a rotational grazing system and in lambs kept indoors, born from the breeding of these females with purebred Santa Ines, Dorper and Suffolk males. Fecal egg counts (FEC), fecal cultures, packed cell volume (PCV) and weights were evaluated during two years. Climate data were registered. Only animals that presented FEC higher than 4,000 and/or PCV lower than 21% were drenched with anthelmintic treatment and this rational use controlled the infection in the flock satisfactorily. An adequate diet during the rainy season and supplementation in dry period were important to increase relative resistance and resilience to parasites, since Haemonchus contortus was detected year-round in this region. The peripartum physiological condition influenced gastrointestinal nematode infections significantly. Crossbred (1/2) Santa Inês + (1/2) Dorper lambs did not show a significant difference in FEC when compared with other breeds, but they had greater live weight and reached slaughter weight earlier.

  17. Investigating anti-parasitic effects of plant secondary metabolites: effects on swine nematodes

    DEFF Research Database (Denmark)

    Williams, Andrew; Pena-Espinoza, Miguel Angel; Fryganas, Christos

    2014-01-01

    is not allowed. Thus, novel parasite-control options are required. We present here results from a comprehensive in vitro screen of plant secondary metabolites (PSM) from diverse plant sources on the economically important pig parasites Ascaris suum and Oesophagostomum dentatum. We focused on two classes of PSM...

  18. Mechanisms of adaptation in the intestinal parasite Giardia lamblia.

    Science.gov (United States)

    Lujan, Hugo D

    2011-01-01

    Giardia lamblia, a parasite of humans, is a major source of waterborne diarrhoeal disease. Giardia is also an excellent system to study basic biochemical processes because it is a single-celled eukaryote with a small genome and its entire life cycle can be replicated in vitro. Giardia trophozoites undergo fundamental changes to survive outside the intestine of their host by differentiating into infective cysts. Encystation entails the synthesis, processing, transport, secretion and extracellular assembly of cyst wall components. To survive within the intestine, Giardia undergoes antigenic variation, a process by which the parasite continuously switches its major surface molecules, allowing the parasite to evade the host's immune response and produce chronic and recurrent infections. The objective of the present chapter is to provide a better understanding of the molecular mechanisms involved in adaptation and differentiation in Giardia, with a particular focus on the process of encystation and antigenic variation of this interesting micro-organism.

  19. Integrated parasite management with special reference to gastro-intestinal nematodes.

    Science.gov (United States)

    Maqbool, I; Wani, Z A; Shahardar, R A; Allaie, I M; Shah, M M

    2017-03-01

    Domestic animals are susceptible to a large number of parasitic diseases, which lead to severe economic losses to livestock industry. So, it is necessary to control parasitic infections in these animals. Control of these helminths is undertaken mostly by anthelmintics, but because of their widespread use there is development of resistance across the globe. However, total dependence on a single method of control has proved to be non-sustainable and cost ineffective in the long term. A combination of treatment and management is necessary to control parasitism so that it will not cause further economic losses to producer as well as to livestock industry. To become practically and ecologically sustainable, parasitic control schemes need to be based on integrated parasite management.

  20. Commercial Biological Control Agents Targeted Against Plant-Parasitic Root-knot Nematodes

    Directory of Open Access Journals (Sweden)

    Marie-Stéphane Tranier

    2014-12-01

    Full Text Available Root-knot nematodes are microscopic round worms, which cause severe agricultural losses. Their attacks affect the productivity by reducing the amount and the caliber of the fruits. Chemical control is widely used, but biological control appears to be a better solution, mainly using microorganisms to reduce the quantity of pests infecting crops. Biological control is developing gradually, and with time, more products are being marketed worldwide. They can be formulated with bacteria, viruses or with filamentous fungi, which can destroy and feed on phytoparasitic nematodes. To be used by the farmers, biopesticides must be legalized by the states, which has led to the establishment of a legal framework for their use, devised by various governmental organizations.

  1. Microarray analysis of gender- and parasite-specific gene transcription in Strongyloides ratti

    NARCIS (Netherlands)

    Evans, Helen; Mello, Luciane V.; Fang, Yongxiang; Wit, Ernst; Thompson, Fiona J.; Viney, Mark E.; Paterson, Steve

    2008-01-01

    The molecular mechanisms by which parasitic nematodes reproduce and have adapted to life within a host are unclear. In the present study, microarray analysis was used to explore differential transcription among the different stages and sexes of Strongyloides ratti, a parasitic nematode of brown

  2. Nematode parasites of two anuran species Rhinella schneideri (Bufonidae and Scinax acuminatus (Hylidae from Corrientes, Argentina

    Directory of Open Access Journals (Sweden)

    Cynthya Elizabeth González

    2008-12-01

    Full Text Available The nematological fauna of most anuran species from Corrientes province, north of Argentina; has not been studied. We report for the first time the nematode species found in Rhinella schneideri and Scinax acuminatus. Forty four amphibians representing two species (R. schneideri -six males, three females and two juveniles- and S. acuminatus -fifteen males and eighteen females were collected near the city of Corrientes, between January 2002 and December 2003 and searched for nematodes. R. schneideri contained eight species of nematodes (adults: Rhabdias füelleborni, R. elegans, Oswaldocruzia proencai, Cosmocerca podicipinus, C. parva and Falcaustra mascula; larvae: Porrocaecum sp. and Physaloptera sp., and S. acuminatus contained three (adults: Cosmocerca parva and Oxyascaris caudacutus; larvae: Physaloptera sp.. We present morphology (scanning electron microscope and metric information, range extensions, and new host records for these nematode species. Rev. Biol. Trop. 56 (4: 2147-2161. Epub 2008 December 12.Cuarenta y cuatro anfibios pertenecientes a dos especies (Rhinella schneideri -seis machos, tres hembras y dos juveniles- y Scinax acuminatus -quince machos y dieciocho hembras fueron recolectados para extraer nemátodos en las proximidades de la ciudad de Corrientes, provincia de Corrientes en Argentina, entre enero 2002 y diciembre 2003. Rhinella schneideri estuvo parasitada por ocho especies de nemátodos (adultos: Rhabdias füelleborni, R. elegans, Oswaldocruzia proencai, Cosmocerca podicipinus, C. parva y Falcaustra mascula; larvas: Porrocaecum sp. y Physaloptera sp., y S. acuminatus presentó tres especies de nemátodos (adultos: Cosmocerca parva y Oxyascaris caudacutus; larva: Physaloptera sp.. Para todas estas especies de nemátodos se presentan datos morfológicos y métricos, y para algunas sus nuevos ámbitos y caracteres, así como también los detalles obtenidos mediante el microscopio electrónico de barrido. Éste es el primer

  3. Differential Metabolic Profiles during the Developmental Stages of Plant-Parasitic Nematode Meloidogyne incognita

    Directory of Open Access Journals (Sweden)

    Parthiban Subramanian

    2017-06-01

    Full Text Available Meloidogyne incognita is a common root-knot nematode with a wide range of plant hosts. We aimed to study the metabolites produced at each stage of the nematode life cycle to understand its development. Metabolites of Meloidogyne incognita were extracted at egg, J2, J3, J4, and female stages and 110 metabolites with available standards were quantified using CE-TOF/MS. Analyses indicated abundance of stage-specific metabolites with the exception of J3 and J4 stages which shared similar metabolic profiles. The egg stage showed increased abundance in glycolysis and energy metabolism related metabolites while the J2 metabolites are associated with tissue formation, motility, and neurotransmission. The J3 and J4 stages indicated amino acid metabolism and urea cycle- related metabolites. The female stage was characterized with polyamine synthesis, antioxidant activity, and synthesis of reproduction related metabolites. Such metabolic profiling helps us understand the dynamic physiological changes related to each developmental stage of the root-knot nematode life cycle.

  4. The Transcriptomes of Xiphinema index and Longidorus elongatus Suggest Independent Acquisition of Some Plant Parasitism Genes by Horizontal Gene Transfer in Early-Branching Nematodes

    Directory of Open Access Journals (Sweden)

    Etienne G.J. Danchin

    2017-10-01

    Full Text Available Nematodes have evolved the ability to parasitize plants on at least four independent occasions, with plant parasites present in Clades 1, 2, 10 and 12 of the phylum. In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been implicated in the evolution of plant parasitism. We have used ribonucleic acid sequencing (RNAseq to generate reference transcriptomes for two economically important nematode species, Xiphinema index and Longidorus elongatus, representative of two genera within the early-branching Clade 2 of the phylum Nematoda. We used a transcriptome-wide analysis to identify putative horizontal gene transfer events. This represents the first in-depth transcriptome analysis from any plant-parasitic nematode of this clade. For each species, we assembled ~30 million Illumina reads into a reference transcriptome. We identified 62 and 104 transcripts, from X. index and L. elongatus, respectively, that were putatively acquired via horizontal gene transfer. By cross-referencing horizontal gene transfer prediction with a phylum-wide analysis of Pfam domains, we identified Clade 2-specific events. Of these, a GH12 cellulase from X. index was analysed phylogenetically and biochemically, revealing a likely bacterial origin and canonical enzymatic function. Horizontal gene transfer was previously shown to be a phenomenon that has contributed to the evolution of plant parasitism among nematodes. Our findings underline the importance and the extensiveness of this phenomenon in the evolution of plant-parasitic life styles in this speciose and widespread animal phylum.

  5. Parasitism by Oestrus ovis: influence of sheep breed and nematode infections.

    Science.gov (United States)

    Silva, B F; Bassetto, C C; Shaw, R J; Canavessi, A M O; Amarante, A F T

    2012-05-25

    Previous studies showed that Santa Ines (SI) hair sheep were more resistant to gastrointestinal nematode infections (GIN) than Ile de France (IF) sheep. The present experiment aimed to evaluate if that reported resistance difference against GIN also occurred against Oestrus ovis infestation and also to evaluate the influence of O. ovis infestation on the gastrointestinal nematodes (GIN) infections. SI (n=12) and IF (n=12) young male lambs were weaned at 2 months of age and moved to a paddock (0.3 ha) with Brachiaria decumbens grass, where they also received concentrate ration. The animals were kept together during the experimental period (September to early December 2009). Fecal and blood samples were taken from all animals every 2 weeks and body weight and nasal discharge score (oestrosis clinic signs) were recorded on the same occasion. In early December 2009, all lambs were sacrificed and O. ovis larvae and GIN were recovered, counted and identified according to the larval stage. All animals were infested by different larval instars of O. ovis without any statistical difference between breeds (P>0.05). The SI lambs had an average of 24.8 larvae, and the intensity of infection ranged between 14 and 39 larvae, while the IF lambs showed an average of 23.5 larvae with the minimum and maximum from 11 to 36 larvae, respectively. SI lambs presented the lowest nematode fecal egg counts (FECs) and the lowest mean numbers of Haemonchus contortus, Trichostrongylus colubriformis and Strongyloides papillosus, however, there was no significant differences between group means (P>0.05). Inverse relationship between numbers of O. ovis larvae and gastrointestinal nematodes was observed in both breeds. SI sheep showed a significant increase in blood eosinophils and total IgE serum levels and these variables were negatively correlated with nematode FEC. A negative correlation was observed between total IgE serum level and H. contortus burden in both breeds. In conclusion, there was

  6. Species of root-knot nematodes and fungal egg parasites recovered from vegetables in Almería and Barcelona, Spain

    OpenAIRE

    Verdejo Lucas, Soledad; Ornat Longarón, Cèsar; Sorribas Royo, Francisco Javier; Stchigel, Alberto Miguel

    2002-01-01

    Intensive vegetable production areas were surveyed in the provinces of Almería (35 sites) and Barcelona (22 sites), Spain, to determine the incidence and identity of Meloidogyne spp. and of fungal parasites of nematode eggs. Two species of Meloidogyne were found in Almería—M. javanica (63% of the samples) and M. incognita (31%). Three species were found in Barcelona, including M. incognita (50%), M. javanica (36%), and M. arenaria (14%). Solanaceous crops supported larger (P < 0.05) nematode ...

  7. Anhydrobiosis and freezing-tolerance: adaptations that facilitate the establishment of Panagrolaimus nematodes in polar habitats.

    Directory of Open Access Journals (Sweden)

    Lorraine M McGill

    Full Text Available Anhydrobiotic animals can survive the loss of both free and bound water from their cells. While in this state they are also resistant to freezing. This physiology adapts anhydrobiotes to harsh environments and it aids their dispersal. Panagrolaimus davidi, a bacterial feeding anhydrobiotic nematode isolated from Ross Island Antarctica, can survive intracellular ice formation when fully hydrated. A capacity to survive freezing while fully hydrated has also been observed in some other Antarctic nematodes. We experimentally determined the anhydrobiotic and freezing-tolerance phenotypes of 24 Panagrolaimus strains from tropical, temperate, continental and polar habitats and we analysed their phylogenetic relationships. We found that several other Panagrolaimus isolates can also survive freezing when fully hydrated and that tissue extracts from these freezing-tolerant nematodes can inhibit the growth of ice crystals. We show that P. davidi belongs to a clade of anhydrobiotic and freezing-tolerant panagrolaimids containing strains from temperate and continental regions and that P. superbus, an early colonizer at Surtsey island, Iceland after its volcanic formation, is closely related to a species from Pennsylvania, USA. Ancestral state reconstructions show that anhydrobiosis evolved deep in the phylogeny of Panagrolaimus. The early-diverging Panagrolaimus lineages are strongly anhydrobiotic but weakly freezing-tolerant, suggesting that freezing tolerance is most likely a derived trait. The common ancestors of the davidi and the superbus clades were anhydrobiotic and also possessed robust freezing tolerance, along with a capacity to inhibit the growth and recrystallization of ice crystals. Unlike other endemic Antarctic nematodes, the life history traits of P. davidi do not show evidence of an evolved response to polar conditions. Thus we suggest that the colonization of Antarctica by P. davidi and of Surtsey by P. superbus may be examples of recent

  8. Anhydrobiosis and freezing-tolerance: adaptations that facilitate the establishment of Panagrolaimus nematodes in polar habitats.

    Science.gov (United States)

    McGill, Lorraine M; Shannon, Adam J; Pisani, Davide; Félix, Marie-Anne; Ramløv, Hans; Dix, Ilona; Wharton, David A; Burnell, Ann M

    2015-01-01

    Anhydrobiotic animals can survive the loss of both free and bound water from their cells. While in this state they are also resistant to freezing. This physiology adapts anhydrobiotes to harsh environments and it aids their dispersal. Panagrolaimus davidi, a bacterial feeding anhydrobiotic nematode isolated from Ross Island Antarctica, can survive intracellular ice formation when fully hydrated. A capacity to survive freezing while fully hydrated has also been observed in some other Antarctic nematodes. We experimentally determined the anhydrobiotic and freezing-tolerance phenotypes of 24 Panagrolaimus strains from tropical, temperate, continental and polar habitats and we analysed their phylogenetic relationships. We found that several other Panagrolaimus isolates can also survive freezing when fully hydrated and that tissue extracts from these freezing-tolerant nematodes can inhibit the growth of ice crystals. We show that P. davidi belongs to a clade of anhydrobiotic and freezing-tolerant panagrolaimids containing strains from temperate and continental regions and that P. superbus, an early colonizer at Surtsey island, Iceland after its volcanic formation, is closely related to a species from Pennsylvania, USA. Ancestral state reconstructions show that anhydrobiosis evolved deep in the phylogeny of Panagrolaimus. The early-diverging Panagrolaimus lineages are strongly anhydrobiotic but weakly freezing-tolerant, suggesting that freezing tolerance is most likely a derived trait. The common ancestors of the davidi and the superbus clades were anhydrobiotic and also possessed robust freezing tolerance, along with a capacity to inhibit the growth and recrystallization of ice crystals. Unlike other endemic Antarctic nematodes, the life history traits of P. davidi do not show evidence of an evolved response to polar conditions. Thus we suggest that the colonization of Antarctica by P. davidi and of Surtsey by P. superbus may be examples of recent "ecological fitting

  9. Anti-parasitic effects of plant secondary metabolites on swine nematodes

    DEFF Research Database (Denmark)

    Williams, A.R.; Pena-Espinoza, Miguel Angel; Fryganas, Christos

    -control options are required. We present results from a comprehensive in vitro screen of plant secondary metabolites (PSM) from diverse plant sources on the economically important pig parasites Ascaris chlamydiae and Oesophagostomum dentatum . We focused on two PSM classes commonly found in natural diets......Organic production presents challenges to animal health and productivity. In organic pig production, animals must have access to outdoor pastures which increases exposure to gastrointestinal parasites. Moreover, the routine use of synthetic anti-parasitic drugs is not allowed. Thus, novel parasite...... – condensed tannins (CT) and sesquiterpene lactones (SL). Different CT-types were purified from various plant sources to reflect their diversity; SL were purified from forage chicory. These PSM were tested in inhibition assays of worm motility and migratory ability. CT had potent activity against A. suum...

  10. Female host sex-biased parasitism with the rodent stomach nematode Mastophorus muris in wild bank voles (Myodes glareolus).

    Science.gov (United States)

    Grzybek, Maciej; Bajer, Anna; Behnke-Borowczyk, Jolanta; Al-Sarraf, Mohammed; Behnke, Jerzy M

    2015-02-01

    Abundance and prevalence of helminth infections often differ between host sexes, and are usually biased in favor of males. Relatively few cases of female-biased parasitism have been reported. We sampled bank voles in three woodland sites in N.E. Poland over 11 years at 3-4-year intervals, and assessed their parasite burdens. Prevalence and abundance of the stomach nematode Mastophorus muris were consistently higher among females. Among adult female bank voles from the two sites that showed the highest prevalence with M. muris, both prevalence and abundance were significantly higher in lactating bank voles, but not pregnant animals, and the effect of lactation was evident in both sites, in all four surveys, and in both age classes. Although the magnitude of the effect of lactation varied between years, it was not confounded by any significant interactions with other factors. We hypothesize that mature and reproductively active female bank voles are subject to higher exposure compared with males of similar age, as a consequence of the increased content of invertebrates in their diet, including the intermediate hosts of M. muris, required to meet the higher increased energy and protein demands of nursing litters throughout the summer months.

  11. Histopathology from liver of tuvira (Gymnotus spp. parasitized by larvae of nematodes

    Directory of Open Access Journals (Sweden)

    Arlene Sobrinho Ventura

    2016-01-01

    Full Text Available ABSTRACT: The aim of this study was to evaluate the histological changes in the liver of thirty-five Gymnotus spp. parasitized by endohelminths collected between April 2012 to October 2013 in commercial bait fish farming of Pantanal basin. Histological cuts of 7µm were stained with hematoxylin-eosin for parasites research and liver changes and have also been submitted to the Perls histochemical method for evaluation of hemosiderosis (Fe+++ based on the incidence degree and severity of change (Grade I, II and III and tests for the presence of central melanomacrophages. Parasites identified were: Brevimulticaecum sp. with a prevalence of 22,9%, Eustrongylides sp 17,1%, Contracaecum type I 68,7%, Contracaecum type II 5,7%, Contracaecum type III 5,7% and larvae of Anisakidae 11,4%. Histological analysis showed intense disorganization of hepatic parenchyma with degenerate hepatocytes due to high parasitic infection, changes that can be deleterious and compromise the organism functioning, being harmful to the health of evaluated animals. Also evidencing normal tissue interleaved with different stages of Fe+++ deposit in grades II and III, injuring or destroing the cell. Histopathological changes in the tuvira's liver suggested a chronic response and the development of a balance relation between tuvira and parasitism by endohelminth identified in this study. There are also a testimony to the health condition of commercial bait fish farming on current ecosystem conditions.

  12. Evaluation of gastro-intestinal nematode parasite control strategies for first-season grazing cattle in Sweden.

    Science.gov (United States)

    Dimander, Sten-Olof; Höglund, Johan; Uggla, Arvid; Spörndly, Eva; Waller, Peter J

    2003-02-13

    in 2000 and resulted in an average 65 kg advantage of the ivermectin treated calves compared with the untreated calves.Thus, this three-year grazing experiment has emphasised the importance of subclinical gastrointestinal nematode infections in FSGC in Sweden. In addition, the study has shown that adequate parasite control may be achievable without the use of anthelmintics.

  13. A synthesis of our current knowledge of philometrid nematodes, a group of increasingly important fish parasites

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; de Buron, I.

    2013-01-01

    Roč. 60, č. 2 (2013), s. 81-101 ISSN 0015-5683 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Nematoda * Philometridae * parasites * fish * taxonomy * morphology * biology * pathology Subject RIV: EA - Cell Biology Impact factor: 1.211, year: 2013

  14. Anti-parasitic effects of plant secondary metabolites on swine nematodes

    DEFF Research Database (Denmark)

    Williams, A.R.; Pena-Espinoza, Miguel Angel; Fryganas, Christos

    -control options are required. We present results from a comprehensive in vitro screen of plant secondary metabolites (PSM) from diverse plant sources on the economically important pig parasites Ascaris chlamydiae and Oesophagostomum dentatum . We focused on two PSM classes commonly found in natural diets...

  15. Distribution of anisakid nematodes parasitizing rajiform skates under commercial exploitation in the Southwestern Atlantic.

    Science.gov (United States)

    Irigoitia, Manuel Marcial; Braicovich, Paola Elizabeth; Lanfranchi, Ana Laura; Farber, Marisa Diana; Timi, Juan Tomás

    2018-02-21

    In order to evaluate the infestation by anisakids present in elasmobranchs and their distribution in the Argentine Sea, this study was carried at a regional scale with the following aims: 1) to identify those anisakid species present in skates under exploitation; 2) to characterize quantitatively these infestations and 3) to determine those factors driving the variability in parasite burdens across skate species. A total of 351 skates, belonging to 3 species (218 Sympterygia bonapartii, 86 Zearaja chilensis and 47 Atlantoraja castelnaui) and from different localities of the Argentine Sea were examined for anisakids. Parasites were found in the stomach wall at high prevalence in some samples. Based on morphology and mtDNA cox2 sequences analyses (from 24 larval worms), specimens were identified as Anisakis berlandi, A. pegreffii and Pseudoterranova cattani; the last two known as potentially pathogenic for humans. Differential distribution patterns were observed across parasite and hosts species. In general, fish caught in southern and deeper waters exhibited higher loads of Anisakis spp., whereas infestation levels by P. cattani increase in larger skates. Taking into account that the mere presence of worms or their antigens in fish meat can provoke allergic responses, information on distribution of parasites and their variability is essential for the implementation of food safety practices. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. In vitro anti-parasitic effects of sesquiterpene lactones from chicory against cattle nematodes

    DEFF Research Database (Denmark)

    Pena-Espinoza, Miguel Angel; Williams, A.; Boas, Ulrik

    . In this study we tested the effect of SL-rich extracts from 2 chicory cultivars on the viability of first-stage larvae (L1) of Ostertagia ostertagi, a pathogenic cattle nematode. Chicory Spadona and Puna II were grown at the same farm and leaves were sampled the same day. 1 g of freeze-dried leaves...... obtained were incubated in 8 extract concentrations for each cultivar (in duplicates) ranging from 2000 μg to 16 μg dry matter (DM) extract/mL (final concentration 1% DMSO in PBS). Ivermectin (1 mg/mL) and 1% DMSO in PBS were used as positive and negative controls, resp. Viability of L1 was evaluated...

  17. Bioactive Volatiles from an Endophytic Daldinia cf. concentrica Isolate Affect the Viability of the Plant Parasitic Nematode Meloidogyne javanica.

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    Orna Liarzi

    Full Text Available Plant-parasitic nematodes form one of the largest sources of biotic stress imposed on plants, and are very difficult to control; among them are the obligate parasites, the sedentary root-knot nematodes (RKNs-Meloidogyne spp.-which are extremely polyphagous and exploit a very wide range of hosts. Endophytic fungi are organisms that spend most of their life cycle within plant tissue without causing visible damage to the host plant. Many endophytes secrete specialized metabolites and/or emit volatile organic compounds (VOCs that exhibit biological activity. Recently, we demonstrated that the endophytic fungus Daldinia cf. concentrica secrets biologically active VOCs. Here we examined the ability of the fungus and its VOCs to control the RKN M. javanica both in vitro and greenhouse experiments. The D. cf. concentrica VOCs showed bionematicidal activity against the second-stage juveniles (J2s of M. javanica. We found that exposure of J2s to fungal volatiles caused 67% reduction in viability, and that application of a synthetic volatile mixture (SVM, comprising 3-methyl-1-butanol, (±-2-methyl-1-butanol, 4-heptanone, and isoamyl acetate, in volumetric ratio of 1:1:2:1 further reduced J2s viability by 99%. We demonstrated that, although each of the four VOCs significantly reduced the viability of J2s relative to the control, only 4-heptanone elicited the same effect as the whole mixture, with nematicidal activity of 90% reduction in viability of the J2s. Study of the effect of the SVM on egg hatching demonstrated that it decreased eggs hatching by 87%. Finally, application of the SVM to soil inoculated with M. javanica eggs or J2s prior to planting susceptible tomato plants resulted in a significantly reduced galling index and fewer eggs produced on each root system, with no effect on root weight. Thus, D. cf. concentrica and/or SVM based on fungal VOCs may be considered as a novel alternative approach to controlling the RKN M. javanica.

  18. Genetic regulation of parasite infection: empirical evidence of the functional significance of an IL4 gene SNP on nematode infections in wild primates

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    Kappeler Peter M

    2011-04-01

    Full Text Available Abstract Background Susceptibility to parasite infection affects fitness-related processes, such as mate choice and survival, yet its genetic regulation remains poorly understood. Interleukin-4 (IL4 plays a central role in the humoral immune defence against nematode parasite infections, inducing IgE switch and regulation of worm expulsion from the intestines. The evolutionary and functional significance of single nucleotide polymorphisms (SNPs in IL4-genes is known, yet empirical information on the effect of IL4 SNPs on gastro-intestinal infections is lacking. Using samples from a population of wild red-fronted lemurs (Eulemur fulvus rufus, Primates: Lemuridae, from western Madagascar, we explored the association of IL4-gene promoter polymorphisms with nematode infections and investigated a possible functional role of the IL4 polymorphism on male reproductive success. Results Using sequence analyses of lemur DNA we detected a new SNP in the IL4 gene promoter area. Carriers of the genotype T/T showed higher nematode infection intensities than individuals of genotypes C/T and C/C. Genetic population analyses using data from more than 10 years, suggested higher reproductive success of T/T males than expected. Conclusions Our results suggest a regulatory effect of an IL4 gene promoter polymorphism on the intensity of parasite infections in a natural population of red-fronted lemurs, with a seemingly disadvantageous genotype represented in low frequencies. Long-term population analyses, however, point in the direction of a negative frequency-dependent association, giving a fitness advantage to the rare genotype. Due to low frequencies of the genotype in question conclusive evidence of a functional role of IL4 polymorphism cannot be drawn here; still, we suggest the use of IL4 polymorphism as a new molecular tool for quick assessment of individual genetic constitution with regard to nematode infection intensities, contributing to a better

  19. The Role of Parasitism in Adaptive Radiations—When Might Parasites Promote and When Might They Constrain Ecological Speciation?

    OpenAIRE

    Karvonen, Anssi; Seehausen, Ole

    2012-01-01

    Research on speciation and adaptive radiation has flourished during the past decades, yet factors underlying initiation of reproductive isolation often remain unknown. Parasites represent important selective agents and have received renewed attention in speciation research. We review the literature on parasite-mediated divergent selection in context of ecological speciation and present empirical evidence for three nonexclusive mechanisms by which parasites might facilitate speciation: reduced...

  20. Genome-wide identification and comprehensive analysis of Excretory/Secretory proteins in nematodes provide potential drug targets for parasite control.

    Science.gov (United States)

    Gahoi, Shachi; Singh, Satendra; Gautam, Budhayash

    2018-03-06

    Nematodes are responsible for causing severe diseases in plants, humans and other animals. Infection is associated with the release of Excretory/Secretory (ES) proteins into host cytoplasm and interference with the host immune system which make them attractive targets for therapeutic use. The identification of ES proteins through bioinformatics approaches is cost- and time-effective and could be used for screening of potential targets for parasitic diseases for further experimental studies. Here, we identified and functionally annotated 93,949 ES proteins, in the genome of 73 nematodes using integration of various bioinformatics tools. 30.6% of ES proteins were found to be supported at RNA level. The predicted ES proteins, annotated by Gene Ontology terms, domains, metabolic pathways, proteases and enzyme class analysis were enriched in molecular functions of proteases, protease inhibitors, c-type lectin and hydrolases which are strongly associated with typical functions of ES proteins. We identified a total of 452 ES proteins from human and plant parasitic nematodes, homologues to DrugBank-approved targets and C. elegans RNA interference phenotype genes which could represent potential targets for parasite control and provide valuable resource for further experimental studies to understand host-pathogen interactions. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Nematophagous fungi as a biological control agent for nematode parasites of small ruminants in Malaysia: a special emphasis on Duddingtonia flagrans.

    Science.gov (United States)

    Chandrawathani, Panchacharam; Jamnah, Omar; Waller, Peter John; Höglund, Johan; Larsen, Michael; Zahari, Wan Mohammed

    2002-01-01

    Approximately 2,800 fresh dung samples from animals, mainly ruminant livestock, were screened for the presence of nematophagous fungi in Malaysia. Arthrobotrys spp. was noted on numerous occasions, but only one isolate of Duddingtonia flagrans was made. For the purposes of producing sufficient quantities of this fungus for feeding trials in sheep, various, commonly available, cheap plant materials were tested as possible growth substrates. This showed that cereal grains (wheat, millet and rice) were the best media for fungal growth. Pen feeding trials were carried out using sheep, both naturally and experimentally infected with nematode parasites (predominantely Haemonchus contortus), to test the efficiency of D. flagrans when administered either in a grain supplement, or incorporated into a feed block. These showed that the fungus survived gut passage in sheep and that dose rates of approximately 1 x 10(6) D. flagrans spores / animal / day, reduced the percentage of infective larvae developing in faecal cultures by more than 90%. These results indicate that using D. flagrans as a biological control agent of nematode parasites, is a promising alternative to nematode parasite control of small ruminants in Malaysia, where anthelmintic resistance is now a major problem.

  2. Nematode parasites of Clarias gariepinus (Burchell, 1822 from the Rietvlei Dam, South Africa

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    M. Barson

    2006-09-01

    Full Text Available Catfish, Clarias gariepinus, from the Rietvlei Dam near Pretoria, South Africa were examined for nem atode parasites. Two species, Procamallanus laeviconchus in the stomach and Contracaecum spp. larvae in the abdominal cavity, were found. The morphology of these species, based on light and scanning electron microscopy, and how they compare with previously described specimens are discussed. Infection rates were mild compared to previous surveys although Contracaecum spp. had a high prevalence of 86 %.

  3. Arbuscular Mycorrhizal Fungi for the Biocontrol of Plant-Parasitic Nematodes: A Review of the Mechanisms Involved.

    Science.gov (United States)

    Schouteden, Nele; De Waele, Dirk; Panis, Bart; Vos, Christine M

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) are obligate root symbionts that can protect their host plant against biotic stress factors such as plant-parasitic nematode (PPN) infection. PPN consist of a wide range of species with different life styles that can cause major damage in many important crops worldwide. Various mechanisms have been proposed to play a role in the biocontrol effect of AMF against PPN. This review presents an overview of the different mechanisms that have been proposed, and discusses into more detail the plausibility of their involvement in the biocontrol against PPN specifically. The proposed mechanisms include enhanced plant tolerance, direct competition for nutrients and space, induced systemic resistance (ISR) and altered rhizosphere interactions. Recent studies have emphasized the importance of ISR in biocontrol and are increasingly placing rhizosphere effects on the foreground as well, both of which will be the focal point of this review. Though AMF are not yet widely used in conventional agriculture, recent data help to develop a better insight into the modes of action, which will eventually lead toward future field applications of AMF against PPN. The scientific community has entered an exciting era that provides the tools to actually unravel the underlying molecular mechanisms, making this a timely opportunity for a review of our current knowledge and the challenges ahead.

  4. Nematodes of Astyanax fasciatus (Actinopterygii: Characidae and their parasitic indices in the São Francisco river, Brazil

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    Flavia Guerra Vieira-Menezes

    Full Text Available Abstract The endoparasite fauna of Astyanax fasciatus from the upper São Francisco river was investigated and ecological parameters and morphological and morphometric data on the parasites are presented. A total of 74 specimens of banded astyanax were collected downstream from the Três Marias dam, municipality of Três Marias, Minas Gerais (18°12’32”S, 45°15’41”W in January 2011 and January 2012. Eleven taxa of Nematoda were found: Contracaecum sp.; Hysterothylacium sp.; Goezia sp.; Brevimulticaecum sp.; Procamallanus sp.; Procamallanus (Spirocamallanus saofranciscencis; Cystidicoloides sp.; Spinitectus rodolphiheringi; Rhabdochona sp.; Spiroxys sp.; and Eustrongylides sp.. The fauna of A. fasciatus consisted of by larval specimens of Contracaecum sp., Hysterothylacium sp., Brevimulticaecum sp., Cystidicoloides sp., and Spiroxys sp., and by adult specimens of P. saofranciscencis, whose prevalence was greater than 10%. Thus, this fish acts as an intermediate host of some species of larval nematodes especially, Anisakidae and Acanthocheilidae (Brevimulticaecum sp., new host record and new locality. It participates in transmitting species such Rhabdochona sp. to carnivorous fish and also acts as a definitive host for P. saofranciscencis and S. rodolphiheringi in the upper São Francisco river.

  5. Nematodes of Astyanax fasciatus (Actinopterygii: Characidae) and their parasitic indices in the São Francisco river, Brazil.

    Science.gov (United States)

    Vieira-Menezes, Flavia Guerra; Costa, Danielle Priscilla Correia; Brasil-Sato, Marilia Carvalho

    2017-01-01

    The endoparasite fauna of Astyanax fasciatus from the upper São Francisco river was investigated and ecological parameters and morphological and morphometric data on the parasites are presented. A total of 74 specimens of banded astyanax were collected downstream from the Três Marias dam, municipality of Três Marias, Minas Gerais (18°12'32"S, 45°15'41"W) in January 2011 and January 2012. Eleven taxa of Nematoda were found: Contracaecum sp.; Hysterothylacium sp.; Goezia sp.; Brevimulticaecum sp.; Procamallanus sp.; Procamallanus (Spirocamallanus) saofranciscencis; Cystidicoloides sp.; Spinitectus rodolphiheringi; Rhabdochona sp.; Spiroxys sp.; and Eustrongylides sp.. The fauna of A. fasciatus consisted of by larval specimens of Contracaecum sp., Hysterothylacium sp., Brevimulticaecum sp., Cystidicoloides sp., and Spiroxys sp., and by adult specimens of P. saofranciscencis, whose prevalence was greater than 10%. Thus, this fish acts as an intermediate host of some species of larval nematodes especially, Anisakidae and Acanthocheilidae (Brevimulticaecum sp., new host record and new locality). It participates in transmitting species such Rhabdochona sp. to carnivorous fish and also acts as a definitive host for P. saofranciscencis and S. rodolphiheringi in the upper São Francisco river.

  6. Anthelmintic effects of forage chicory (Cichorium intybus) against gastrointestinal nematode parasites in experimentally infected cattle

    DEFF Research Database (Denmark)

    Pena-Espinoza, Miguel Angel; Thamsborg, Stig M.; Desrues, Olivier

    2016-01-01

    Two experiments studied the effects of dietary chicory against gastrointestinal nematodes in cattle. In Experiment (Exp.) 1, stabled calves were fed chicory silage (CHI1; n = 9) or ryegrass/clover hay (CTL1; n = 6) with balanced protein/energy intakes between groups. After 16 days, all calves...... received 10 000 Ostertagia ostertagi and 66 000 Cooperia oncophora third-stage larvae (L3) [day (D) 0 post-infection (p.i.)]. In Exp. 2, calves were assigned to pure chicory (CHI2; n=10) or ryegrass/clover (CTL2; n = 10) pastures. After 7 days, animals received 20 000 O. ostertagi L3/calf (D0 p.......i.) and were moved regularly preventing pasture-borne infections. Due to poor regrowth of the chicory pasture, CHI2 was supplemented with chicory silage. At D40 p.i. (Exp. 1) and D35 p.i. (Exp. 2) calves were slaughtered for worm recovery. In Exp.1, fecal egg counts (FEC) were similar between groups. However...

  7. New filarial nematode from Japanese serows (Naemorhedus crispus: Bovidae close to parasites from elephants

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    Uni S.

    2006-09-01

    Full Text Available A new onchocercid species, Loxodontofilaria caprini n. sp. (Filarioidea: Nematoda, found in subcutaneous tissues of 37 (33% of 112 serows (Naemorhedus crispus examined in Japan, is described. The female worm had the characteristics of Loxodontofilaria, e.g., the large body size, well-developed esophagus with a shallow buccal cavity, and the long tail with three caudal lappets. The male worm of the new species, which was first described in the genus, had unequal length of spicules, 10 pairs of pre- and post-caudal papillae, and three terminal caudal lappets. Deirids were present in both sexes. Among four species of the genus Loxodontofilaria: one from the hippopotamus and three from the Elepantidae, L. caprini n. sp. appears close to L. asiatica Bain, Baker & Chabaud, 1982, a subcutaneous parasite of Elephas indicus in Myanmar (Burma. However, L. caprini n. sp. is distinct from L. asiatica in that the Japanese female worm has an esophagus half as long and the microfilariae also half as long with a coiled posterior. The microfilariae were found in the skin of serows. The new parasite appears to clearly illustrate a major event in the evolution of onchocercids: the host-switching. This might have occurred on the Eurasian continent, where elephantids and the lineage of rupicaprines diversified during the Pliocene-Pleistocene, or in Japan, into which some of these hosts migrated.

  8. Phylogenetic relationships of some spirurine nematodes (Nematoda: Chromadorea: Rhabditida: Spirurina) parasitic in fishes inferred from SSU rRNA gene sequences.

    Science.gov (United States)

    Cernotíková, Eva; Horák, Ales; Moravec, Frantisek

    2011-06-01

    Abstract: Small subunit rRNA sequences were obtained from 38 representatives mainly of the nematode orders Spirurida (Camallanidae, Cystidicolidae, Daniconematidae, Philometridae, Physalopteridae, Rhabdochonidae, Skrjabillanidae) and, in part, Ascaridida (Anisakidae, Cucullanidae, Quimperiidae). The examined nematodes are predominantly parasites of fishes. Their analyses provided well-supported trees allowing the study ofphylogenetic relationships among some spirurine nematodes. The present results support the placement of Cucullanidae at the base of the suborder Spirurina and, based on the position of the genus Philonema (subfamily Philoneminae) forming a sister group to Skrjabillanidae (thus Philoneminae should be elevated to Philonemidae), the paraphyly of the Philometridae. Comparison of a large number of sequences of representatives of the latter family supports the paraphyly of the genera Philometra, Philometroides and Dentiphilometra. The validity of the newly included genera Afrophilometra and Caranginema is not supported. These results indicate geographical isolation has not been the cause of speciation in this parasite group and no coevolution with fish hosts is apparent. On the contrary, the group of South-American species ofAlinema, Nilonema and Rumai is placed in an independent branch, thus markedly separated from other family members. Molecular data indicate that the skrjabillanid subfamily Esocineminae (represented by Esocinema bohemicum) should be either elevated to the rank of an independent family or Daniconematidae (Mexiconema africanum) should be decreased to Daniconematinae and transferred to the family Skrjabillanidae. Camallanid genera Camallanus and Procamallanus, as well as the subgenera Procamallanus and Spirocamallanus are confirmed to be paraphyletic. Paraphyly has also been found within Filarioidea, Habronematoidea and Thelazioidea and in Cystidicolidae, Physalopteridae and Thelaziidae. The results of the analyses also show that

  9. The effect of purified condensed tannins of forage plants from Botswana on the free-living stages of gastrointestinal nematode parasites of livestock.

    Science.gov (United States)

    Tibe, O; Sutherland, I A; Lesperance, L; Harding, D R K

    2013-10-18

    The effect of condensed tannins (CT) extracted from forage plants from Botswana on the free-living stages of a number of species of gastrointestinal nematode parasites derived from infected sheep were investigated using in vitro assays. Fresh samples of five different plants (Viscum rotundifolium, Viscum verrucosum, Tapinanthus oleifolius, Grewia flava and Ipomoea sinensis) were collected over two summers (February 2009 and 2010). Fractionation of each crude extract on a Sephadex LH-20 column yielded low molecular weight phenolics and CT-containing fractions. The effect of each purified CT fraction on parasites was evaluated using either egg hatch, larval development or larval migration inhibition assays. Three gastrointestinal nematode species (Haemonchus contortus, Trichostrongylus colubriformis and Teladorsagia circumcincta) derived from infected sheep were evaluated in the study. CT from V. rotundifolium and I. sinensis fractions from samples collected in 2009 and 2010 did not inhibit larval development. However, CT isolated from V. verrucosum, T. oleifolius and G. flava collected in 2009 completely inhibited the development of all parasite species. These CT fractions were more potent in inhibiting larval development of H. contortus than fractions from the same plant species collected in 2010. However, a slight effect on larval migration was observed with some CT extracts. The results suggest that CT extracts of some forage plants from Botswana have anti-parasitic properties in vitro, and that further research is required to determine any in vivo efficacy from feeding the plants to goats in a field situation. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Genomic-bioinformatic analysis of transcripts enriched in the third-stage larva of the parasitic nematode Ascaris suum.

    Directory of Open Access Journals (Sweden)

    Cui-Qin Huang

    2008-06-01

    (Lva (23.5% and larval lethality (Lvl (47%. A genetic interaction network was predicted for these 17 C. elegans orthologues, revealing highly significant interactions for nine molecules associated with embryonic and larval development (66.9%, information storage and processing (5.1%, cellular processing and signaling (15.2%, metabolism (6.1%, and unknown function (6.7%. The potential roles of these molecules in development are discussed in relation to the known roles of their homologues/orthologues in C. elegans and some other nematodes. The results of the present study provide a basis for future functional genomic studies to elucidate molecular aspects governing larval developmental processes in A. suum and/or the transition to parasitism.

  11. Genetics, chromatin diminution, and sex chromosome evolution in the parasitic nematode genus Strongyloides.

    Science.gov (United States)

    Nemetschke, Linda; Eberhardt, Alexander G; Hertzberg, Hubertus; Streit, Adrian

    2010-10-12

    When chromatin diminution occurs during a cell division a portion of the chromatin is eliminated, resulting in daughter cells with a smaller amount of genetic material. In the parasitic roundworms Ascaris and Parascaris, chromatin diminution creates a genetic difference between the soma and the germline. However, the function of chromatin diminution remains a mystery, because the vast majority of the eliminated DNA is noncoding. Within the parasitic roundworm genus Strongyloides, S. stercoralis (in man) and S. ratti (in rat) employ XX/XO sex determination, but the situation in S. papillosus (in sheep) is different but controversial. We demonstrate genetically that S. papillosus employs sex-specific chromatin diminution to eliminate an internal portion of one of the two homologs of one chromosome pair in males. Contrary to ascarids, the eliminated DNA in S. papillosus contains a large number of genes. We demonstrate that the region undergoing diminution is homologous to the X chromosome of the closely related S. ratti. The flanking regions, which are not diminished, are homologous to the S. ratti autosome number I. Furthermore, we found that the diminished chromosome is not incorporated into sperm, resulting in a male-specific transmission ratio distortion. Our data indicate that on the evolutionary path to S. papillosus, the X chromosome fused with an autosome. Chromatin diminution serves to functionally restore an XX/XO sex-determining system. A consequence of the fusion and the process that copes with it is a transmission ratio distortion in males for certain loci. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Sewage sludge amendment and inoculation with plant-parasitic nematodes do not facilitate the internalization of Salmonella Typhimurium LT2 in lettuce plants.

    Science.gov (United States)

    Fornefeld, Eva; Baklawa, Mohamed; Hallmann, Johannes; Schikora, Adam; Smalla, Kornelia

    2018-05-01

    Contamination of fruits and vegetables with Salmonella is a serious threat to human health. In order to prevent possible contaminations of fresh produce it is necessary to identify the contributing ecological factors. In this study we investigated whether the addition of sewage sludge or the presence of plant-parasitic nematodes foster the internalization of Salmonella enterica serovar Typhimurium LT2 into lettuce plants, posing a potential threat for human health. Greenhouse experiments were conducted to investigate whether the amendment of sewage sludge to soil or the presence of plant-parasitic nematodes Meloidogyne hapla or Pratylenchus crenatus promote the internalization of S. Typhimurium LT2 from soil into the edible part of lettuce plants. Unexpectedly, numbers of cultivable S. Typhimurium LT2 decreased faster in soil with sewage sludge than in control soil but not in root samples. Denaturing gradient gel electrophoresis analysis revealed shifts of the soil bacterial communities in response to sewage sludge amendment and time. Infection and proliferation of nematodes inside plant roots were observed but did not influence the number of cultivable S. Typhimurium LT2 in the root samples or in soil. S. Typhimurium LT2 was not detected in the leaf samples 21 and 49 days after inoculation. The results indicate that addition of sewage sludge, M. hapla or P. crenatus to soil inoculated with S. Typhimurium LT2 did not result in an improved survival in soil or internalization of lettuce plants. Copyright © 2017. Published by Elsevier Ltd.

  13. Influence of management and biological factors on parasitic invasions in the wild – Spread of the blood-sucking nematode Ashworthius sidemi in European bison (Bison bonasus

    Directory of Open Access Journals (Sweden)

    Marta Kołodziej-Sobocińska

    2016-12-01

    Full Text Available The full course of new parasite introductions in wild animals is difficult to accurately trace. We documented and analysed the invasive blood-sucking nematode Ashworthius sidemi (Trichostrongylidae introduction and spread in European bison (Bison bonasus from the initial phase of its progression. In the Polish part of the Białowieża Primeval Forest (BPF the parasite was first found in 2000. From 2002 to 2015, 165 culled bison were investigated. The prevalence and intensity of A. sidemi Schulz, 1933 infection increased over the following years, reaching 100% of investigated bison four years after introduction and a maximal median intensity of 8200 nematodes per animal in the winter of 2008/2009. Afterwards, a significant decline of median infection intensity was observed to the minimum value of 410 nematodes per animal. Between 2011 and 2014 prevalence varied from 89 to 100%. Among the factors analysed, the number of years since introduction, herd size, age and sex proved to significantly influence infection intensity. A higher infection intensity was recorded in sub-adults compared to juveniles and adults. Males had significantly lower infection intensity than females, but this was the case for adults only. The highest infection intensities were recorded in the biggest bison herds, where the winter supplementary feeding of bison is intense. Moreover, the longer the parasite was present in the host population, the more important herd size became as a factor. Our study indicates that it is not solely biological factors that determine the spread of a newly detected parasite in wildlife, but that management practices can also have a strong influence. This is especially important in endangered species under intensive human care as the management practices may pose a threat to the species.

  14. RNA interference in adult Ascaris suum--an opportunity for the development of a functional genomics platform that supports organism-, tissue- and cell-based biology in a nematode parasite.

    Science.gov (United States)

    McCoy, Ciaran J; Warnock, Neil D; Atkinson, Louise E; Atcheson, Erwan; Martin, Richard J; Robertson, Alan P; Maule, Aaron G; Marks, Nikki J; Mousley, Angela

    2015-09-01

    The sustainable control of animal parasitic nematodes requires the development of efficient functional genomics platforms to facilitate target validation and enhance anthelmintic discovery. Unfortunately, the utility of RNA interference (RNAi) for the validation of novel drug targets in nematode parasites remains problematic. Ascaris suum is an important veterinary parasite and a zoonotic pathogen. Here we show that adult A. suum is RNAi competent, and highlight the induction, spread and consistency of RNAi across multiple tissue types. This platform provides a new opportunity to undertake whole organism-, tissue- and cell-level gene function studies to enhance target validation processes for nematode parasites of veterinary/medical significance. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Towards the molecular characterisation of parasitic nematode assemblages: an evaluation of terminal-restriction fragment length polymorphism (T-RFLP) analysis.

    Science.gov (United States)

    Lott, M J; Hose, G C; Power, M L

    2014-09-01

    Identifying factors which regulate temporal and regional structuring within parasite assemblages requires the development of non-invasive techniques which facilitate both the rapid discrimination of individual parasites and the capacity to monitor entire parasite communities across time and space. To this end, we have developed and evaluated a rapid fluorescence-based method, terminal restriction fragment length polymorphism (T-RFLP) analysis, for the characterisation of parasitic nematode assemblages in macropodid marsupials. The accuracy with which T-RFLP was capable of distinguishing between the constituent taxa of a parasite community was assessed by comparing sequence data from two loci (the ITS+ region of nuclear ribosomal DNA and the mitochondrial CO1) across ∼20 species of nematodes (suborder Strongylida). Our results demonstrate that with fluorescent labelling of the forward and reverse terminal restriction fragments (T-RFs) of the ITS+ region, the restriction enzyme Hinf1 was capable of generating species specific T-RFLP profiles. A notable exception was within the genus Cloacina, in which closely related species often shared identical T-RFs. This may be a consequence of the group's comparatively recent evolutionary radiation. While the CO1 displayed higher sequence diversity than the ITS+, the subsequent T-RFLP profiles were taxonomically inconsistent and could not be used to further differentiate species within Cloacina. Additionally, several of the ITS+ derived T-RFLP profiles exhibited unexpected secondary peaks, possibly as a consequence of the restriction enzymes inability to cleave partially single stranded amplicons. These data suggest that the question of T-RFLPs utility in monitoring parasite communities cannot be addressed without considering the ecology and unique evolutionary history of the constituent taxa. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Transgenesis in Strongyloides and related parasitic nematodes: historical perspectives, current functional genomic applications and progress towards gene disruption and editing.

    Science.gov (United States)

    Lok, J B; Shao, H; Massey, H C; Li, X

    2017-03-01

    Transgenesis for Strongyloides and Parastrongyloides was accomplished in 2006 and is based on techniques derived for Caenorhabditis elegans over two decades earlier. Adaptation of these techniques has been possible because Strongyloides and related parasite genera carry out at least one generation of free-living development, with adult males and females residing in soil contaminated by feces from an infected host. Transgenesis in this group of parasites is accomplished by microinjecting DNA constructs into the syncytia of the distal gonads of free-living females. In Strongyloides stercoralis, plasmid-encoded transgenes are expressed in promoter-regulated fashion in the F1 generation following gene transfer but are silenced subsequently. Stable inheritance and expression of transgenes in S. stercoralis requires their integration into the genome, and stable lines have been derived from integrants created using the piggyBac transposon system. More direct investigations of gene function involving expression of mutant transgene constructs designed to alter intracellular trafficking and developmental regulation have shed light on the function of the insulin-regulated transcription factor Ss-DAF-16. Transgenesis in Strongyloides and Parastrongyloides opens the possibility of powerful new methods for genome editing and transcriptional manipulation in this group of parasites. Proof of principle for one of these, CRISPR/Cas9, is presented in this review.

  17. Genetic control of acquired resistance to gastrointestinal nematode parasites in sheep

    International Nuclear Information System (INIS)

    Windon, R.G.; Wagland, B.M.; Dineen, J.K.

    1988-01-01

    A radiation attenuated larval vaccine has been used to evaluate the role of genetic components of the immune response in the control of Trichostrongylus colubriformis in sheep. Through selection based on age dependent responsiveness, lines of sheep have been established in which lambs are either high or low responders to vaccination and challenge infection. The estimated and realized heritabilities for the selected trait are 0.35-0.41. Significant interline differences were demonstrated and, within the lines, ewe lambs were consistently more responsive than rams or wethers. The effect of selection was not antigenically specific, since high responsiveness to T. colubriformis was associated with increased responsiveness to other related (T. rugatus) and unrelated parasites (Ostertagia circumcincta and Haemonchus contortus). In addition, high responders had a more vigorous reaction against naturally acquired infections than low responders. The general immunological competence was also increased in high responders; this was shown by the levels of serum complement fixing antibody to larval antigens after vaccination and challenge, in vitro blastogenic responses stimulated by larval antigens and the phagocytic function of peripheral leucocytes. No production penalty (weight gain and wool growth) was associated with heightened responsiveness. (author). 10 refs, 1 fig

  18. Structural Basis for Carbohydrate Recognition and Anti-inflammatory Modulation by Gastrointestinal Nematode Parasite Toxascaris leonina Galectin*

    Science.gov (United States)

    Hwang, Eun Young; Jeong, Mi Suk; Park, Sang Kyun; Ha, Sung Chul; Yu, Hak Sun; Jang, Se Bok

    2016-01-01

    Toxascaris leonina galectin (Tl-gal) is a galectin-9 homologue protein isolated from an adult worm of the canine gastrointestinal nematode parasite, and Tl-gal-vaccinated challenge can inhibit inflammation in inflammatory bowel disease-induced mice. We determined the first X-ray structures of full-length Tl-gal complexes with carbohydrates (lactose, N-acetyllactosamine, lacto-N-tetraose, sialyllactose, and glucose). Bonds were formed on concave surfaces of both carbohydrate recognition domains (CRDs) in Tl-gal. All binding sites were found in the HXXXR and WGXEER motifs. Charged Arg61/Arg196 and Glu80/Glu215 on the conserved motif of Tl-gal N-terminal CRD and C-terminal CRD are critical amino acids for recognizing carbohydrate binding, and the residues can affect protein folding and structure. The polar amino acids His, Asn, and Trp are also important residues for the interaction with carbohydrates through hydrogen bonding. Hemagglutination activities of Tl-gal were inhibited by interactions with carbohydrates and mutations. We found that the mutation of Tl-gal (E80A/E215A) at the carbohydrate binding region induced protein aggregation and could be caused in many diseases. The short linker region between the N-terminal and C-terminal CRDs of Tl-gal was very stable against proteolysis and maintained its biological activity. This structural information is expected to elucidate the carbohydrate recognition mechanism of Tl-gal and improve our understanding of anti-inflammatory mediators and modulators of immune response. PMID:27742836

  19. The nicotinic acetylcholine receptors of the parasitic nematode Ascaris suum: formation of two distinct drug targets by varying the relative expression levels of two subunits.

    Directory of Open Access Journals (Sweden)

    Sally M Williamson

    2009-07-01

    Full Text Available Parasitic nematodes are of medical and veterinary importance, adversely affecting human health and animal welfare. Ascaris suum is a gastrointestinal parasite of pigs; in addition to its veterinary significance it is a good model of the human parasite Ascaris lumbricoides, estimated to infect approximately 1.4 billion people globally. Anthelmintic drugs are essential to control nematode parasites, and nicotinic acetylcholine receptors (nAChRs on nerve and muscle are the targets of cholinergic anthelmintics such as levamisole and pyrantel. Previous genetic analyses of nematode nAChRs have been confined to Caenorhabditis elegans, which is phylogenetically distinct from Ascaris spp. and many other important parasites. Here we report the cloning and expression of two nAChR subunit cDNAs from A. suum. The subunits are very similar in sequence to C. elegans UNC-29 and UNC-38, are expressed on muscle cells and can be expressed robustly in Xenopus oocytes to form acetylcholine-, nicotine-, levamisole- and pyrantel-sensitive channels. We also demonstrate that changing the stoichiometry of the receptor by injecting different ratios of the subunit cRNAs can reproduce two of the three pharmacological subtypes of nAChR present in A. suum muscle cells. When the ratio was 5:1 (Asu-unc-38ratioAsu-unc-29, nicotine was a full agonist and levamisole was a partial agonist, and oocytes responded to oxantel, but not pyrantel. At the reverse ratio (1:5 Asu-unc-38ratioAsu-unc-29, levamisole was a full agonist and nicotine was a partial agonist, and the oocytes responded to pyrantel, but not oxantel. These results represent the first in vitro expression of any parasitic nicotinic receptor and show that their properties are substantially different from those of C. elegans. The results also show that changing the expression level of a single receptor subunit dramatically altered the efficacy of some anthelmintic drugs. In vitro expression of these subunits may permit the

  20. Effect of temperature on different stages of Romanomermis iyengari, a mermithid nematode parasite of mosquitoes

    Directory of Open Access Journals (Sweden)

    K. P. Paily

    1994-12-01

    Full Text Available The effect of temperature (20 degrees-35 degrees C on different stages of Romanomermis iyengari was studied. In embryonic development, the single-cell stage eggs developed into mature eggs in 4.5-6.5 days at 25-35 degrees C but, required 9.5 days at 20 degrees C. Complete hatching occurred in 7 and 9 days after egg-laying at 35 and 30 degrees C, respectively. At 25 and 20 degrees C, 85-96 of the eggs did not hatch even by 30th day. Loss of infectivity and death of the preparasites occurred faster at higher temperatures. The 50 survival durations of preparasites at 20 and 35 degrees C were 105.8 and 10.6 hr respectively. They retained 50 infectivity up to 69.7 and 30.3 hr. The duration of the parasitic phase increased as temperature decreased. Low temperature favoured production of a higher proportion of females which were also larger in size. The maximum time taken for the juveniles to become adults was 14 days at 20 degrees C and the minimum was 9 days at 35 degrees C. Oviposition began earlier at higher temperature than at lower temperature. However, its fecundic period was shorter at 20 degrees C than at 35 degrees C indicating enhanced rate of oviposition at 20 degrees C. Fecundity was adversely affected at 20 degrees C and 35 degrees C. It is shown that the temperature range of 25 degrees-30 degrees C favours optimum development of R. iyengari.

  1. Chemotaxis can take plant-parasitic nematodes to the source of a chemo-attractant via the shortest possible routes.

    Science.gov (United States)

    Reynolds, Andy M; Dutta, Tushar K; Curtis, Rosane H C; Powers, Stephen J; Gaur, Hari S; Kerry, Brian R

    2011-04-06

    It has long been recognized that chemotaxis is the primary means by which nematodes locate host plants. Nonetheless, chemotaxis has received scant attention. We show that chemotaxis is predicted to take nematodes to a source of a chemo-attractant via the shortest possible routes through the labyrinth of air-filled or water-filled channels within a soil through which the attractant diffuses. There are just two provisos: (i) all of the channels through which the attractant diffuses are accessible to the nematodes and (ii) nematodes can resolve all chemical gradients no matter how small. Previously, this remarkable consequence of chemotaxis had gone unnoticed. The predictions are supported by experimental studies of the movement patterns of the root-knot nematodes Meloidogyne incognita and Meloidogyne graminicola in modified Y-chamber olfactometers filled with Pluronic gel. By providing two routes to a source of the attractant, one long and one short, our experiments, the first to demonstrate the routes taken by nematodes to plant roots, serve to test our predictions. Our data show that nematodes take the most direct route to their preferred hosts (as predicted) but often take the longest route towards poor hosts. We hypothesize that a complex of repellent and attractant chemicals influences the interaction between nematodes and their hosts.

  2. Epidemiological studies of parasitic gastrointestinal nematodes, cestodes and coccidia infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe

    Directory of Open Access Journals (Sweden)

    D.M. Pfukenyi

    2007-09-01

    Full Text Available Between January 1999 and December 2000 faecal samples from 16 264 cattle at 12 dipping sites in the highveld and nine in the lowveld communal grazing areas of Zimbabwe were examined for gastrointestinal (GI nematode and cestodes eggs, and coccidia oocysts. Strongyle larvae were identified following culture of pooled faecal samples collected at monthly intervals. The effects of region, age, sex and season on the prevalence of GI nematodes, cestodes and coccidia were determined. Faecal egg and oocyst counts showed an overall prevalence of GI nematodes of 43 %, coccidia 19.8 % and cestodes 4.8 %. A significantly higher prevalence of infection with GI nematodes, cestodes and coccidia was recorded in calves (P < 0.01 than in adults. Pregnant and lactating cows had significantly higher prevalences than bulls, oxen and non-lactating (dry cows (P < 0.01. The general trend of eggs per gram (epg of faeces and oocysts per gram (opg of faeces was associated with the rainfall pattern in the two regions, with high epg and opg being recorded during the wet months. The most prevalent genera of GI nematodes were Cooperia, Haemonchus and Trichostrongylus in that order. Strongyloides papillosus was found exclusively in calves. Haemonchus was significantly more prevalent during the wet season than the dry season (P < 0.01. In contrast, Trichostrongylus was present in significantly (P < 0.01 higher numbers during the dry months than the wet months, while Cooperia and Oesophagostomum revealed no significant differences between the wet and dry season. These findings are discussed with reference to their relevance for strategic control of GI parasites in cattle in communal grazing areas of Zimbabwe.

  3. In vivo effects of Sainfoin (Onobrychis viciifolia) on parasitic nematodes in calves

    DEFF Research Database (Denmark)

    Desrues, Oliver; Pena-Espinoza, Miguel Angel; Hansen, T.V.A.

    , and the intestinal worm Cooperia oncophora. Jersey male calves (2-4 months) reared indoor and GIN naive, were stratified for live weight and randomly allocated into a test group (SF; n=9) which was fed 80% sainfoin (cv. Perly) pellets and hay, and a control group (CO; n=6) fed hay and compound feed. Daily intake...... was monitored and protein/energy intake was equalized in both groups throughout the 8 weeks study period. After 2 weeks adaptation, calves were inoculated with approximately 10,000 O. ostertagi and 65,000 C. oncophora infective third-stage larvae. Individual weight gain was registered weekly, whereas eggs...... excretion, calculated as number of eggs per g of faecal dry matter (FECDM) was recorded 3 times a week. The calves were slaughtered and adult worms recovered 6 weeks post infection. FECDM was analysed by ANOVA using repeated measurements, and worm counts by Kruskal Wallis test. The mean FECDM...

  4. Effects of associated bacteria on the pathogenicity and reproduction of the insect-parasitic nematode Rhabditis blumi (Nematoda: Rhabditida).

    Science.gov (United States)

    Park, Hae Woong; Kim, Yong Ook; Ha, Jae-Seok; Youn, Sung Hun; Kim, Hyeong Hwan; Bilgrami, Anwar L; Shin, Chul Soo

    2011-09-01

    Three bacteria, Alcaligenes faecalis , Flavobacterium sp., and Providencia vermicola , were isolated from dauer juveniles of Rhabditis blumi . The pathogenic effects of the bacteria against 4th instar larvae of Galleria mellonella were investigated. Providencia vermicola and Flavobacterium sp. showed 100% mortality at 48 h after haemocoelic injection, whereas A. faecalis showed less than 30% mortality. Dauer juveniles showed 100% mortality against G. mellonella larvae, whereas axenic juveniles, which do not harbor associated bacteria, exhibited little mortality. All of the associated bacteria were used as a food source for nematode growth, and nematode yield differed with bacterial species. Among the bacterial species, P. vermicola was most valued for nematode yield, showing the highest yield of 5.2 × 10(4) nematodes/mL in the plate. In bacterial cocultures using two of the three associated bacteria, one kind stimulated the other. The highest total bacterial yield of 12.6 g/L was obtained when the inoculum ratio of P. vermicola to A. faecalis was 10:1. In air-lift bioreactors, the nematode growth rate increased with an increasing level of dissolved oxygen. The maximum nematode yield of 1.75 × 10(5) nematodes/mL was obtained at 192 h with an aeration rate of 6 vvm.

  5. Nematode assemblages in the rhizosphere of spring barley (Hordeum vulgare L.) depended on fertilisation and plant growth phase

    DEFF Research Database (Denmark)

    Madsen, Mette Vestergård

    2004-01-01

    rhizosphere; nitrogen and phosphorus fertilisation; nematode assemblages; plant parasites; barley......rhizosphere; nitrogen and phosphorus fertilisation; nematode assemblages; plant parasites; barley...

  6. Nematode parasites of four species of Carangoides (Osteichthyes: Carangidae) in New Caledonian waters, with a description of Philometra dispar n. sp. (Philometridae).

    Science.gov (United States)

    Moravec, František; Gey, Delphine; Justine, Jean-Lou

    2016-01-01

    Parasitological examination of marine perciform fishes belonging to four species of Carangoides, i.e. C. chrysophrys, C. dinema, C. fulvoguttatus and C. hedlandensis (Carangidae), from off New Caledonia revealed the presence of nematodes. The identification of carangids was confirmed by barcoding of the COI gene. The eight nematode species found were: Capillariidae gen. sp. (females), Cucullanus bulbosus (Lane, 1916) (male and females), Hysterothylacium sp. third-stage larvae, Raphidascaris (Ichthyascaris) sp. (female and larvae), Terranova sp. third-stage larvae, Philometra dispar n. sp. (male), Camallanus carangis Olsen, 1954 (females) and Johnstonmawsonia sp. (female). The new species P. dispar from the abdominal cavity of C. dinema is mainly characterised by the body length (5.14 mm), the lengths of markedly unequal spicules (163 and 96 μm) and gubernaculum (102 μm long) provided with a dorsal protuberance and a small, reflexed dorsal barb on its posterior portion. The finding of C. bulbosus represents the first record of this parasite a century after its discovery; the first study of this species by scanning electron microscopy (SEM) enabled detailed redescription. The finding of Johnstonmawsonia sp. in C. fulvoguttatus is the first record of a rhabdochonid nematode from a host belonging to the Carangidae family. Johnstonmawsonia africana Moravec & Puylaert, 1970 and J. campanae Puylaert, 1973 are transferred to Prosungulonema Roytman, 1963 as P. africanum (Moravec & Puylaert, 1970) comb. n. and P. campanae (Puylaert, 1973) n. comb. © F. Moravec et al., published by EDP Sciences, 2016.

  7. Transposon-mediated chromosomal integration of transgenes in the parasitic nematode Strongyloides ratti and establishment of stable transgenic lines.

    Directory of Open Access Journals (Sweden)

    Hongguang Shao

    Full Text Available Genetic transformation is a potential tool for analyzing gene function and thereby identifying new drug and vaccine targets in parasitic nematodes, which adversely affect more than one billion people. We have previously developed a robust system for transgenesis in Strongyloides spp. using gonadal microinjection for gene transfer. In this system, transgenes are expressed in promoter-regulated fashion in the F1 but are silenced in subsequent generations, presumably because of their location in repetitive episomal arrays. To counteract this silencing, we explored transposon-mediated chromosomal integration of transgenes in S. ratti. To this end, we constructed a donor vector encoding green fluorescent protein (GFP under the control of the Ss-act-2 promoter with flanking inverted tandem repeats specific for the piggyBac transposon. In three experiments, free-living Strongyloides ratti females were transformed with this donor vector and a helper plasmid encoding the piggyBac transposase. A mean of 7.9% of F1 larvae were GFP-positive. We inoculated rats with GFP-positive F1 infective larvae, and 0.5% of 6014 F2 individuals resulting from this host passage were GFP-positive. We cultured GFP-positive F2 individuals to produce GFP-positive F3 L3i for additional rounds of host and culture passage. Mean GFP expression frequencies in subsequent generations were 15.6% in the F3, 99.0% in the F4, 82.4% in the F5 and 98.7% in the F6. The resulting transgenic lines now have virtually uniform GFP expression among all progeny after at least 10 generations of passage. Chromosomal integration of the reporter transgenes was confirmed by Southern blotting and splinkerette PCR, which revealed the transgene flanked by S. ratti genomic sequences corresponding to five discrete integration sites. BLAST searches of flanking sequences against the S. ratti genome revealed integrations in five contigs. This result provides the basis for two powerful functional genomic tools

  8. Transposon-mediated chromosomal integration of transgenes in the parasitic nematode Strongyloides ratti and establishment of stable transgenic lines.

    Science.gov (United States)

    Shao, Hongguang; Li, Xinshe; Nolan, Thomas J; Massey, Holman C; Pearce, Edward J; Lok, James B

    2012-01-01

    Genetic transformation is a potential tool for analyzing gene function and thereby identifying new drug and vaccine targets in parasitic nematodes, which adversely affect more than one billion people. We have previously developed a robust system for transgenesis in Strongyloides spp. using gonadal microinjection for gene transfer. In this system, transgenes are expressed in promoter-regulated fashion in the F1 but are silenced in subsequent generations, presumably because of their location in repetitive episomal arrays. To counteract this silencing, we explored transposon-mediated chromosomal integration of transgenes in S. ratti. To this end, we constructed a donor vector encoding green fluorescent protein (GFP) under the control of the Ss-act-2 promoter with flanking inverted tandem repeats specific for the piggyBac transposon. In three experiments, free-living Strongyloides ratti females were transformed with this donor vector and a helper plasmid encoding the piggyBac transposase. A mean of 7.9% of F1 larvae were GFP-positive. We inoculated rats with GFP-positive F1 infective larvae, and 0.5% of 6014 F2 individuals resulting from this host passage were GFP-positive. We cultured GFP-positive F2 individuals to produce GFP-positive F3 L3i for additional rounds of host and culture passage. Mean GFP expression frequencies in subsequent generations were 15.6% in the F3, 99.0% in the F4, 82.4% in the F5 and 98.7% in the F6. The resulting transgenic lines now have virtually uniform GFP expression among all progeny after at least 10 generations of passage. Chromosomal integration of the reporter transgenes was confirmed by Southern blotting and splinkerette PCR, which revealed the transgene flanked by S. ratti genomic sequences corresponding to five discrete integration sites. BLAST searches of flanking sequences against the S. ratti genome revealed integrations in five contigs. This result provides the basis for two powerful functional genomic tools in S. ratti

  9. Risk factors of gastrointestinal nematode parasite infections in small ruminants kept in smallholder mixed farms in Kenya

    Directory of Open Access Journals (Sweden)

    Gachuiri Charles K

    2007-04-01

    Full Text Available Abstract Background Helminth infections in small ruminants are serious problems in the developing world, particularly where nutrition and sanitation are poor. This study investigated the burden and risk factors of gastrointestinal nematode parasite infections in sheep and goats kept in smallholder mixed farms in the Kenyan Central Highlands. Three hundred and seven small ruminants were sampled from 66 smallholder mixed farms in agro-ecological zones 1 (humid and 3 (semi-humid in the Kenyan Central highlands. The farms were visited once a month for eight months during which a health and production survey questionnaire was administered. Fecal samples were collected at each visit from each animal. Fecal egg counts (FEC were performed using the modified McMaster technique. Associations between potential risk factors and FEC were assessed using 3-level Poisson models fit in SAS using GLIMMIX macro. Correlations among repeated observations were adjusted for using three different correlation structures. Results A rise in FEC was observed two months after the onset of rains. Farmer education, age category, de-worming during the preceding month and grazing system were significant predictors of FEC. Additionally, there were significant interactions between grazing system and both de-worming and age category implying that the effect of grazing system is dependent on both de-worming status and age category; and that the effect of de-worming depends on the grazing system. The most important predictors of FEC in the study area were grazing system, de-worming status and education of the farmers. Conclusion Since several factors were important predictors of FEC, controlling gastrointestinal helminths of small ruminants in these resource-poor smallholder mixed farms requires a sustainable integrated helminth control strategy that includes adoption of zero-grazing and more farmer education probably through extension services. Achieving improved helminth controls

  10. High rate of adaptation of mammalian proteins that interact with Plasmodium and related parasites.

    Science.gov (United States)

    Ebel, Emily R; Telis, Natalie; Venkataram, Sandeep; Petrov, Dmitri A; Enard, David

    2017-09-01

    Plasmodium parasites, along with their Piroplasm relatives, have caused malaria-like illnesses in terrestrial mammals for millions of years. Several Plasmodium-protective alleles have recently evolved in human populations, but little is known about host adaptation to blood parasites over deeper evolutionary timescales. In this work, we analyze mammalian adaptation in ~500 Plasmodium- or Piroplasm- interacting proteins (PPIPs) manually curated from the scientific literature. We show that (i) PPIPs are enriched for both immune functions and pleiotropy with other pathogens, and (ii) the rate of adaptation across mammals is significantly elevated in PPIPs, compared to carefully matched control proteins. PPIPs with high pathogen pleiotropy show the strongest signatures of adaptation, but this pattern is fully explained by their immune enrichment. Several pieces of evidence suggest that blood parasites specifically have imposed selection on PPIPs. First, even non-immune PPIPs that lack interactions with other pathogens have adapted at twice the rate of matched controls. Second, PPIP adaptation is linked to high expression in the liver, a critical organ in the parasite life cycle. Finally, our detailed investigation of alpha-spectrin, a major red blood cell membrane protein, shows that domains with particularly high rates of adaptation are those known to interact specifically with P. falciparum. Overall, we show that host proteins that interact with Plasmodium and Piroplasm parasites have experienced elevated rates of adaptation across mammals, and provide evidence that some of this adaptation has likely been driven by blood parasites.

  11. Plasmodial Hsp70s are functionally adapted to the malaria parasite life cycle

    Directory of Open Access Journals (Sweden)

    Jude M Przyborski

    2015-06-01

    Full Text Available The human malaria parasite, Plasmodium falciparum, encodes a minimal complement of six heat shock protein 70s (PfHSP70s, some of which are highly expressed and are thought to play an important role in the survival and pathology of the parasite. In addition to canonical features of molecular chaperones, these HSP70s possess properties that reflect functional adaptation to a parasitic life style, including resistance to thermal insult during fever periods and host-parasite interactions. The parasite even exports an HSP70 to the host cell where it is likely to be involved in host cell modification. This review focuses on the features of the PfHSP70s, particularly with respect to their adaptation to the malaria parasite life cycle.

  12. Nematode parasites of groundnut

    Science.gov (United States)

    Groundnut is the common name for several leguminous plant species producing seed that mature underground, including Bambara groundnut (Vigna subterranean), Hausa groundnut (Macrotyloma geocarpum), and peanut (Arachis spp.). Hausa groundnut is cultivated as a food crop primarily in West Africa and t...

  13. Venom allergen-like proteins in secretions of plant-parasitic nematodes activate and suppress extracellular plant immune receptors

    NARCIS (Netherlands)

    Lozano Torres, J.L.

    2014-01-01

    Parasitic worms threaten human, animal and plant health by infecting people, livestock and crops worldwide. Animals and plants share an anciently evolved innate immune system. Parasites modulate this immune system by secreting proteins to maintain their parasitic lifestyle. This thesis

  14. Venom allergen-like proteins in secretions of plant-parasitic nematodes activate and suppress extracellular plant immune receptors

    NARCIS (Netherlands)

    Lozano Torres, J.L.

    2014-01-01

      Parasitic worms threaten human, animal and plant health by infecting people, livestock and crops worldwide. Animals and plants share an anciently evolved innate immune system. Parasites modulate this immune system by secreting proteins to maintain their parasitic lifestyle. This thesis

  15. Effect of the nematode-trapping fungus Duddingtonia flagrans on the free-living stages of horse parasitic nematodes: a plot study

    DEFF Research Database (Denmark)

    Fernandez, A.S.; Larsen, M.; Nansen, P.

    1997-01-01

    deposition, a subsample of the herbage surrounding each dung pat was collected and the number of larvae on the grass determined. Also, the larval reduction capacity of the fungus was evaluated by faecal cultures set up from all groups of horses. The faecal cultures showed that a sufficient number of spores......A plot experiment was conducted to investigate the ability of the nematode-trapping fungus Duddingtonia flagrans to reduce the transmission of infective horse strongyle larvae from deposited dung onto surrounding herbage. At three different times during the summer 1995, three groups of horses...... the transmission of infective larvae in all groups, resulting in low numbers of larvae on the herbage. During the rainy periods a significant reduction in the number of larvae recovered was observed around all fungal containing pats. There were no significant differences between the number of fungal spares...

  16. A model plant pathogen from the kingdom Animalia: Heterodera glycines, the soybean cyst nematode.

    Science.gov (United States)

    Niblack, T L; Lambert, K N; Tylka, G L

    2006-01-01

    The soybean cyst nematode, Heterodera glycines, adversely affects the production of soybean, Glycine max, in many areas of the world, particularly in the United States, where it is the most economically important soybean pathogen. Despite the availability of hundreds of H. glycines-resistant soybean cultivars, the nematode continues to be a major limiting factor in soybean production. The use of nonhost rotation and resistance are the primary means of reducing losses caused by the nematode, but each of these options has disadvantages. As a subject for study of nematode parasitism and virulence, H. glycines provides a useful model despite its obligately parasitic nature. Its obligately sexual reproduction and ready adaptation to resistant cultivars, formerly referred to as "race shift," presents an excellent opportunity for the study of virulence in nematodes. Recent advances in H. glycines genomics have helped identify putative nematode parasitism genes, which, in turn, will aid in the understanding of nematode pathogenicity and virulence and may provide new targets for engineering nematode resistance.

  17. Identification of plant-parasitic nematodes of ornamental bulbs and use of hidrotermotherapy to control Pratylenchus crenatus on lily

    Directory of Open Access Journals (Sweden)

    Samara Azevedo Oliveira

    2012-06-01

    Jet Set imported from Netherlands. The most efficient variation of time and temperature assessed was the thermal bath at 39ºC per two hours, which showed to be efficient in the control of nematodes without affect the plants development.

  18. Genomes of parasitic nematodes (Meloidogyne hapla, Meloidogyne incognita, Ascaris suum and Brugia malayi) have a reduced complement of small RNA interference pathway genes: knockdown can reduce host infectivity of M. incognita.

    Science.gov (United States)

    Iqbal, Sadia; Fosu-Nyarko, John; Jones, Michael G K

    2016-07-01

    The discovery of RNA interference (RNAi) as an endogenous mechanism of gene regulation in a range of eukaryotes has resulted in its extensive use as a tool for functional genomic studies. It is important to study the mechanisms which underlie this phenomenon in different organisms, and in particular to understand details of the effectors that modulate its effectiveness. The aim of this study was to identify and compare genomic sequences encoding genes involved in the RNAi pathway of four parasitic nematodes: the plant parasites Meloidogyne hapla and Meloidogyne incognita and the animal parasites Ascaris suum and Brugia malayi because full genomic sequences were available-in relation to those of the model nematode Caenorhabditis elegans. The data generated was then used to identify some potential targets for control of the root knot nematode, M. incognita. Of the 84 RNAi pathway genes of C. elegans used as model in this study, there was a 42-53 % reduction in the number of effectors in the parasitic nematodes indicating substantial differences in the pathway between species. A gene each from six functional groups of the RNAi pathway of M. incognita was downregulated using in vitro RNAi, and depending on the gene (drh-3, tsn-1, rrf-1, xrn-2, mut-2 and alg-1), subsequent plant infection was reduced by up to 44 % and knockdown of some genes (i.e. drh-3, mut-2) also resulted in abnormal nematode development. The information generated here will contribute to defining targets for more robust nematode control using the RNAi technology.

  19. Parasites contribute to ecologically dependent postmating isolation in the adaptive radiation of three-spined stickleback.

    Science.gov (United States)

    El Nagar, Aliya; MacColl, Andrew D C

    2016-08-17

    Spatial variation in parasitic infections is common, and has the potential to drive population divergence and the reproductive isolation of hosts. However, despite support from theory and model laboratory systems, little strong evidence has been forthcoming from the wild. Here, we show that parasites are likely to cause reproductive isolation in the adaptive radiation of three-spined stickleback. Adjacent wild populations on the Scottish island of North Uist differ greatly and consistently in the occurrence of different parasites that have substantial effects on fitness. Laboratory-reared fish are more resistant to experimental infection by parasite species from their own population. Furthermore, hybrid backcrosses between the host populations are more resistant to parasites from the parental population to which they are more closely related. These patterns provide strong evidence that parasites can cause ecological speciation, by contributing to selection against migrants and ecologically dependent postmating isolation. © 2016 The Author(s).

  20. Development of Some Larval Nematodes in Experimental and Natural Animal Hosts: An Insight into Development of Pathological Lesions vis-a-vis Host-Parasite Interactions

    Directory of Open Access Journals (Sweden)

    N. Chowdhury

    2013-01-01

    Full Text Available Infective third-stage larvae of three spiruroid nematodes, Ascarops strongylina and Physocephalus sexalatus of pigs and Spirocerca lupi of dogs, were recovered from 14 species of coprophagous beetles belonging to 4 different genera. These larvae were fed to rabbits and/or guinea pigs to study their development in these experimental hosts. Larvae of A. strongylina reached the adult stage in all rabbits and one guinea pig. The adult worms recovered in these hosts were 40% and 4%, respectively, and became diminutive in comparison to their natural hosts. The larvae of P. sexalatus became reencysted in the gastric wall of rabbits inducing marked pathological changes. The infective larvae of S. lupi became reencapsulated in the stomach wall of the rabbit and also showed development in the aortic wall. Adults of Toxocara canis of dog, collected from 5 different regions of the Indian subcontinent, varied significantly in size. The mouse passage of infective larvae of one of these types led to the recovery of the adults from the experimental dogs that were smaller in size and caused severe pathology in natural experimental hosts. Developmental effects shown in experimental hosts and host specificity are of value in understanding the evolution of nematode parasitism.

  1. Parasitism of two zoonotic reservoirs Dasyprocta leporina and D. fuliginosa (Rodentia) from Amazonas, with Trichostrongylina nematodes (Heligmonellidae): description of a new genus and a new species.

    Science.gov (United States)

    Gonçalves, Alessandra Queiroga; Pinto, Roberto Magalhães; Durette-Desset, Marie-Claude

    2007-09-01

    A new genus and a new species of Heligmonellidae nematodes are described parasiting the stomach of three agoutis (two Dasyprocta fuliginosa and one D. leporina) captured in the middle and high Negro river microregion, state of Amazonas, Brazil. The new genus, as well as its type-species, are closely related to the trichostrongylids included in Fuellebornema, particularly on what concerns the pattern of the caudal bursa, but differing from them by the characteristics of the synlophe, that presents a poorly developed carene, when compared to the referred number of body ridges in Freitastrongylus n. gen. and consequently in F. angelae n. sp.,in which the ridges are well developed and the carene at mid-body has a similar size when compared to the ridge situated in front of the right field (ridge no. 5). Caudal bursa is of the type 1-4, with rays 9 shorter than rays 10, with a very long genital cone.

  2. A survey of zoonotic nematodes of commercial key fish species from major European fishing grounds-Introducing the FP7 PARASITE exposure assessment study

    DEFF Research Database (Denmark)

    Levsen, Arne; Svanevik, Cecilie S.; Cipriani, Paolo

    2018-01-01

    assessment survey was organized within WP2. The surveillance task also provided the data or samples needed for data management and sample storage (WP3, Biobank), molecular and genetic parasite species identification (WP4), and statistical modelling and inference (WP8). In total 17,760 fish belonging to 16...... teleost species were examined for anisakids, with special emphasis on economically and ecologically important species such as Atlantic mackerel, herring, European hake, Atlantic cod and anchovy. The target fish species were sampled at four major European fishing areas including the Barents Sea, North Sea...... as number of fish host species and sample size. An important requirement of the survey was the use of commonly accepted nematode detection methods, i.e. the UV-press method or artificial digestion, to quantify infection level and spatial distribution of anisakid larvae in the target fish species. The basic...

  3. Nematode parasites of the Chilean Flamingo, Phoenicopterus chilensis (Phoenicopteridae) from Central Argentina, with a description of a new species of Tetrameres (Tetrameridae).

    Science.gov (United States)

    Núñez, Verónica; Drago, Fabiana B; Digiani, María Celina; Lunaschi, Lia I

    2017-06-01

    During the summer of 2013, several specimens of Phoenicopterus chilensis (Phoenicopteridae) were found dead from unknown causes, in lakes from the endorheic system "Encadenadas del Oeste", Buenos Aires Province, Argentina. Two species of Nematoda were recovered from the proventriculus, one of them new for science. The tetramerid Tetrameres (Tetrameres) salina n. sp. is mainly characterized by having reduced pseudolabia, lips absent, six bifid teeth, males with lateral alae, four rows of somatic spines and length ratio of spicules 1:12-32, and large females with eggs lacking polar filaments. The acuariid, Echinuria skrjabinensis is described and illustrated, this finding represent the second report of this nematode in Argentina and the first record in flamingos. This is the first record of helminths parasitizing wild Chilean Flamingos, but it is not possible to ensure that they accomplish their life cycle in this system of lakes, because the migratory movements of the population of flamingos studied are unknown.

  4. Parasitism of two zoonotic reservoirs Dasyprocta leporina and D. fuliginosa (Rodentia from Amazonas, with Trichostrongylina nematodes (Heligmonellidae: description of a new genus and a new species

    Directory of Open Access Journals (Sweden)

    Alessandra Queiroga Gonçalves

    2007-09-01

    Full Text Available A new genus and a new species of Heligmonellidae nematodes are described parasiting the stomach of three agoutis (two Dasyprocta fuliginosa and one D. leporina captured in the middle and high Negro river microregion, state of Amazonas, Brazil. The new genus, as well as its type-species, are closely related to the trichostrongylids included in Fuellebornema, particularly on what concerns the pattern of the caudal bursa, but differing from them by the characteristics of the synlophe, that presents a poorly developed carene, when compared to the referred number of body ridges in Freitastrongylus n. gen. and consequently in F. angelae n. sp.,in which the ridges are well developed and the carene at mid-body has a similar size when compared to the ridge situated in front of the right field (ridge no. 5. Caudal bursa is of the type 1-4, with rays 9 shorter than rays 10, with a very long genital cone.

  5. Research and implementation of novel approaches for the control of nematode parasites in Latin America and the Caribbean: is there sufficient incentive for a greater extension effort?

    Science.gov (United States)

    Torres-Acosta, J F J; Molento, M; Mendoza de Gives, P

    2012-05-04

    The widespread presence of anthelmintic resistant gastrointestinal parasitic nematodes in outdoor ruminant production systems has driven the need to identify and develop novel approaches for the control of helminths with the intention to reduce the dependence on commercial anthelmintic drugs. This paper identifies what has been done in Latin America (LA) in terms of estimating the prevalence of anthelmintic resistance (AR) in ruminant production systems and the application of different novel approaches for the control of helminths in those systems, including research and extension activities. Firstly, the paucity of knowledge of AR is discussed in the context of different countries, as well as, the available economic resources for research, the technical infrastructure available and the practical difficulties of the production systems. It is then proposed that the search for novel approaches is not only driven by AR but also by the need for techniques that are feasible for application by resource-poor farmers in non-commercial subsistence farming systems. However, the commercial benefits of these approaches are often limited and so are funding inputs in most countries. The workers participating in the research into different novel approaches are identified as well as the different methods being studied in the different areas of LA according to their published results. In addition, the difficulties experienced during extension efforts to reach farmers and help them to adopt novel approaches for the control of parasitic nematodes in LA are discussed. The role of regulatory authorities in these countries is discussed as some methods of control might need an official confirmation of their efficacy as well as authorization prior to application as they may affect animal products (i.e. residues) and/or impose a hazard for animal welfare. The role of the pharmaceutical companies is also discussed. Copyright © 2011. Published by Elsevier B.V.

  6. The application of Arabidopsis thaliana in studying tripartite interactions among plants, beneficial fungal endophytes and biotrophic plant-parasitic nematodes.

    Science.gov (United States)

    Martinuz, Alfonso; Zewdu, Getaneh; Ludwig, Nicole; Grundler, Florian; Sikora, Richard A; Schouten, Alexander

    2015-04-01

    The research demonstrated that Arabidopsis can be used as a model system for studying plant-nematode-endophyte tripartite interactions; thus, opening new possibilities for further characterizing the molecular mechanisms behind these interactions. Arabidopsis has been established as an important model system for studying plant biology and plant-microbe interactions. We show that this plant can also be used for studying the tripartite interactions among plants, the root-knot nematode Meloidogyne incognita and a beneficial endophytic isolate of Fusarium oxysporum, strain Fo162. In various plant species, Fo162 can systemically reduce M. incognita infection development and fecundity. Here it is shown that Fo162 can also colonize A. thaliana roots without causing disease symptoms, thus behaving as a typical endophyte. As observed for other plants, this endophyte could not migrate from the roots into the shoots and leaves. Direct inoculation of the leaves also did not result in colonization of the plant. A significant increase in plant fresh weight, root length and average root diameter was observed, suggesting the promotion of plant growth by the endophyte. The inoculation of A. thaliana with F. oxysporum strain Fo162 also resulted in a significant reduction in the number of M. incognita juveniles infecting the roots and ultimately the number of galls produced. This was also observed in a split-root experiment, in which the endophyte and nematode were spatially separated. The usefulness of Arabidopsis opens new possibilities for further dissecting complex tripartite interactions at the molecular and biochemical level.

  7. How do humans affect wildlife nematodes?

    Science.gov (United States)

    Weinstein, Sara B.; Lafferty, Kevin D.

    2015-01-01

    Human actions can affect wildlife and their nematode parasites. Species introductions and human-facilitated range expansions can create new host–parasite interactions. Novel hosts can introduce parasites and have the potential to both amplify and dilute nematode transmission. Furthermore, humans can alter existing nematode dynamics by changing host densities and the abiotic conditions that affect larval parasite survival. Human impacts on wildlife might impair parasites by reducing the abundance of their hosts; however, domestic animal production and complex life cycles can maintain transmission even when wildlife becomes rare. Although wildlife nematodes have many possible responses to human actions, understanding host and parasite natural history, and the mechanisms behind the changing disease dynamics might improve disease control in the few cases where nematode parasitism impacts wildlife.

  8. In-vitro predatory activity of nematophagous fungi from Costa Rica with potential use for controlling sheep and goat parasitic nematodes

    Directory of Open Access Journals (Sweden)

    Natalia Soto-Barrientos

    2011-03-01

    Full Text Available In tropical and subtropical regions of the world, parasitic diseases are a main cause of losses in livestock productivity. The increased acquired resistence to anthelmintics by gastrointestinal nematodes, requires biological control be considered as a potential feasible and effective alternative. The most effective natural soil enemies of nematodes are nematophagous fungi. In order to collect and identify predator nematophagous fungi (PNF, samples were obtained from 51 farms distributed throughout the seven provinces of Costa Rica. The origin samples included: soil from different crops (potatoes, tomatoes, bananas, ornamental plants, squash and coffee; animal feces (cattle, sheep, goat and horse; soil and fallen leaves from forest; and plants with signs of nematode infection. Each sample was processed using three techniques for the extraction of fungi from soil: sprinkling technique, soil dilution and humidity chamber. Twenty four strains of nematophagous fungi were found in 19 farms; 83.3% of the fungi were isolated by sprinkling technique. The following fungi were idenified: Arthrobotrys oligospora (n=13; Candelabrella musiformis (n=9; and for the first time there was isolation of A. conoides (n=1 and A. dactyloides (n=1 in the country. Moreover, 16 strains from Trichoderma (n=13, Beauveria (n=1, Clonostachys (n=1 and Lecanicillium (n=1 were obtained. In addition, pH of each possible fungal isolation source was measured, and it varied from 5.2 to 9.9, however PNF isolates fell within the range of 5.6 to 7.5. The PNF strains were cultivated in four different media for the production of chhlamydospores: potato dextrose agar (PDA; corn meal agar (CMA; malt extract agar (MEA and potato carrot agar (PCA. Out of these cultures, 95.8% of the strains formed chlamydospores primarily in the PCA. Of these strains, the profilic spore producers were subjected to ruminant artificial gastrointestinal conditions. A total of 14 fungi were tested, out of which

  9. Plasmalogen enrichment in exosomes secreted by a nematode parasite versus those derived from its mouse host: implications for exosome stability and biology

    Directory of Open Access Journals (Sweden)

    Fabio Simbari

    2016-07-01

    Full Text Available Extracellular vesicles (EVs mediate communication between cells and organisms across all 3 kingdoms of life. Several reports have demonstrated that EVs can transfer molecules between phylogenetically diverse species and can be used by parasites to alter the properties of the host environment. Whilst the concept of vesicle secretion and uptake is broad reaching, the molecular composition of these complexes is expected to be diverse based on the physiology and environmental niche of different organisms. Exosomes are one class of EVs originally defined based on their endocytic origin, as these derive from multivesicular bodies that then fuse with the plasma membrane releasing them into the extracellular environment. The term exosome has also been used to describe any small EVs recovered by high-speed ultracentrifugation, irrespective of origin since this is not always well characterized. Here, we use comparative global lipidomic analysis to examine the composition of EVs, which we term exosomes, that are secreted by the gastrointestinal nematode, Heligmosomoides polygyrus, in relation to exosomes secreted by cells of its murine host. Ultra-performance liquid chromatography – tandem mass spectrometry (UPLC-MS/MS analysis reveals a 9- to 62-fold enrichment of plasmalogens, as well as other classes of ether glycerophospholipids, along with a relative lack of cholesterol and sphingomyelin (SM in the nematode exosomes compared with those secreted by murine cells. Biophysical analyses of the membrane dynamics of these exosomes demonstrate increased rigidity in those from the nematode, and parallel studies with synthetic vesicles support a role of plasmalogens in stabilizing the membrane structure. These results suggest that nematodes can maintain exosome membrane structure and integrity through increased plasmalogens, compensating for diminished levels of other lipids, including cholesterol and SM. This work also illuminates the prevalence of

  10. Adaptations to host infection and larval parasitism in Unionoida

    Science.gov (United States)

    Christopher M. Barnhart; Wendell R. Haag; William N. Roston

    2008-01-01

    Freshwater mussel larval parasitism of fish is unique among bivalves. The relationship is primarily phoretic rather than nutritive; only the smallest glochidia and the haustorial larva grow substantially while on the host. Growth of the smallest larvae suggests a lower functional size limit of -150 )um for the juvenile stage. Most Ambleminae, the most diverse North...

  11. First report on nematode parasite infection in the yellowbar angelfish Pomacanthus maculosus (Perciformes: Pomacanthidae) from the Iraqi coral reef, with description of a new species of Cucullanus (Nematoda: Ascaridida) using the integrated approaches.

    Science.gov (United States)

    Li, Liang; Ali, Atheer H; Zhao, Wen-Ting; Lü, Liang; Xu, Zhen

    2016-12-01

    The yellowbar angelfish Pomacanthus maculosus (Forsskål) (Perciformes: Pomacanthidae) is a beautiful, marine ornamental fish with very important commercial value. However, to date, no information is available on nematode parasite infection in P. maculosus. In the present study, the integrated approaches including light and scanning electron microscopy, and sequencing and analysing ribosomal [small ribosomal DNA (18S) and internal transcribed spacer (ITS)] and mitochondrial [cytochrome c oxidase subunit 1 (cox1)] target regions, respectively, were employed for the systematic evaluation of the nematode parasites firstly isolated from P. maculosus in the Iraqi coral reef. The results revealed that these nematodes represent a new species of Cucullanus (Ascaridida: Cucullanidae). The phylogenetic analyses based on 18S, ITS and cox1 sequences were constructed, respectively, to assess the phylogenetic relationships between the new species and the other cucullanids, and the monophyly of Cucullanus, as well as some its related genus-level taxa. The results supported C. extraneus n. sp. appear to be sister to C. hainanensis, and the genera Cucullanus, Dichelyne and Truttaedacnitis may be not monophyletic assemblages. This is the first report of the occurrence of nematode parasites in P. maculosus. Copyright © 2016. Published by Elsevier Ireland Ltd.

  12. Host responses to interspecific brood parasitism: a by-product of adaptations to conspecific parasitism?

    Science.gov (United States)

    Samas, Peter; Hauber, Mark E; Cassey, Phillip; Grim, Tomas

    2014-01-01

    Why have birds evolved the ability to reject eggs? Typically, foreign egg discrimination is interpreted as evidence that interspecific brood parasitism (IP) has selected for the host's ability to recognize and eliminate foreign eggs. Fewer studies explore the alternative hypothesis that rejection of interspecific eggs is a by-product of host defenses, evolved against conspecific parasitism (CP). We performed a large scale study with replication across taxa (two congeneric Turdus thrushes), space (populations), time (breeding seasons), and treatments (three types of experimental eggs), using a consistent design of egg rejection experiments (n = 1057 nests; including controls), in areas with potential IP either present (Europe; native populations) or absent (New Zealand; introduced populations). These comparisons benefited from the known length of allopatry (one and a half centuries), with no gene flow between native and introduced populations, which is rarely available in host-parasite systems. Hosts rejected CP at unusually high rates for passerines (up to 60%). CP rejection rates were higher in populations with higher conspecific breeding densities and no risks of IP, supporting the CP hypothesis. IP rejection rates did not covary geographically with IP risk, contradicting the IP hypothesis. High egg rejection rates were maintained in the relatively long-term isolation from IP despite non-trivial rejection costs and errors. These egg rejection patterns, combined with recent findings that these thrushes are currently unsuitable hosts of the obligate parasitic common cuckoo (Cuculus canorus), are in agreement with the hypothesis that the rejection of IP is a by-product of fine-tuned egg discrimination evolved due to CP. Our study highlights the importance of considering both IP and CP simultaneously as potential drivers in the evolution of egg discrimination, and illustrates how populations introduced to novel ecological contexts can provide critical insights

  13. Meloidogyne lusitanica n. sp. (Nematoda: Meloidogynidae), a Root-knot Nematode Parasitizing Olive Tree (Olea europaea L.)

    OpenAIRE

    de O. Abrantes, Isabel M.; de A. Santos, M. Susana N.

    1991-01-01

    A root-knot nematode from Portugal, Meloidogyne lusitanica n. sp., is described and illustrated from specimens obtained from olive trees (Olea europaea L.). Females of the new species have a characteristic perineal pattern with medium to high trapezoidal dorsal arch with distinct punctuations in the tail terminus area. The excretory pore is located posterior to the stylet, about 1.5-2.5 stylet lengths from the anterior end. The stylet is 17.1 μm long with pear-shaped knobs. Males have a round...

  14. Parasites

    Centers for Disease Control (CDC) Podcasts

    2010-05-06

    In this podcast, a listener wants to know what to do if he thinks he has a parasite or parasitic disease.  Created: 5/6/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 5/6/2010.

  15. A harpin elicitor induces the expression of a coiled-coil nucleotide binding leucine rich repeat (CC-NB-LRR) defense signaling gene and others functioning during defense to parasitic nematodes.

    Science.gov (United States)

    Aljaafri, Weasam A R; McNeece, Brant T; Lawaju, Bisho R; Sharma, Keshav; Niruala, Prakash M; Pant, Shankar R; Long, David H; Lawrence, Kathy S; Lawrence, Gary W; Klink, Vincent P

    2017-12-01

    The bacterial effector harpin induces the transcription of the Arabidopsis thaliana NON-RACE SPECIFIC DISEASE RESISTANCE 1/HARPIN INDUCED1 (NDR1/HIN1) coiled-coil nucleotide binding leucine rich repeat (CC-NB-LRR) defense signaling gene. In Glycine max, Gm-NDR1-1 transcripts have been detected within root cells undergoing a natural resistant reaction to parasitism by the syncytium-forming nematode Heterodera glycines, functioning in the defense response. Expressing Gm-NDR1-1 in Gossypium hirsutum leads to resistance to Meloidogyne incognita parasitism. In experiments presented here, the heterologous expression of Gm-NDR1-1 in G. hirsutum impairs Rotylenchulus reniformis parasitism. These results are consistent with the hypothesis that Gm-NDR1-1 expression functions broadly in generating a defense response. To examine a possible relationship with harpin, G. max plants topically treated with harpin result in induction of the transcription of Gm-NDR1-1. The result indicates the topical treatment of plants with harpin, itself, may lead to impaired nematode parasitism. Topical harpin treatments are shown to impair G. max parasitism by H. glycines, M. incognita and R. reniformis and G. hirsutum parasitism by M. incognita and R. reniformis. How harpin could function in defense has been examined in experiments showing it also induces transcription of G. max homologs of the proven defense genes ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1), TGA2, galactinol synthase, reticuline oxidase, xyloglucan endotransglycosylase/hydrolase, alpha soluble N-ethylmaleimide-sensitive fusion protein (α-SNAP) and serine hydroxymethyltransferase (SHMT). In contrast, other defense genes are not directly transcriptionally activated by harpin. The results indicate harpin induces pathogen associated molecular pattern (PAMP) triggered immunity (PTI) and effector-triggered immunity (ETI) defense processes in the root, activating defense to parasitic nematodes. Copyright © 2017. Published by Elsevier

  16. Nematode parasites of marsupials and small rodents from the Brazilian Atlantic Forest in the State of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Delir Corrêa Gomes

    2003-12-01

    Full Text Available Nematodes from opossums and rodents captured in the Brazilian Atlantic Forest in the State of Rio de Janeiro, Brazil were studied. From the opossums Didelphis aurita Weid-Neuweid, 1826 and Philander opossum (Linnaeus, 1758 the following nematode species were recovered: Viannaia hamata Travassos, 1914, Aspidodera raillieti Travassos, 1913, Cruzia tentaculata (Rudolphi, 1819, Travassos, 1917, Turgida turgida (Rudolphi, 1819 Travassos, 1919, Gongylonemoides marsupialis (Vaz & Pereira, 1934 Freitas & Lent, 1937, Viannaia viannai Travassos, 1914, Spirura guianensis (Ortlepp, 1924 Chitwood, 1938 and from the rodents Akodon cursor (Winger, 1887, Nectomys squamipes (Brants, 1827, Oligoryzomys eliurus (Wagner, 1845 and Oryzomys intermedius (Leche, 1886: Hassalstrongylus epsilon (Travassos, 1937 Durette-Desset, 1971, Syphacia obvelata (Rudolphi, 1802 Seurat, 1916, S. venteli Travassos, 1937, Physaloptera bispiculata Vaz & Pereira, 1935, Litomosoides carinii (Travassos, 1919 Vaz, 1934, Viannaia viannai, Hassalstrongylus epsilon, H. zeta (Travassos, 1937 Durette-Desset, 1971, Stilestrongylus aculeata (Travassos, 1918 Durette-Desset, 1971 S. eta (Travassos, 1937 Durette-Desset, 1971. Highest worm burdens and prevalences were those related to Cruzia tentaculata in marsupials. Stilestrongylus aculeata was referred for the first time in Akodon cursor.

  17. Soil properties and olive cultivar determine the structure and diversity of plant-parasitic nematode communities infesting olive orchards soils in southern Spain.

    Science.gov (United States)

    Palomares-Rius, Juan E; Castillo, Pablo; Montes-Borrego, Miguel; Navas-Cortés, Juan A; Landa, Blanca B

    2015-01-01

    This work has studied for the first time the structure and diversity of plant-parasitic nematodes (PPNs) infesting olive orchard soils in a wide-region in Spain that included 92 locations. It aims at determining which agronomical or environmental factors associated to the olive orchards are the main drivers of the PPNs community structure and diversity. Classical morphological and morphometric identification methods were used to determine the frequency and densities of PPNs. Thirteen families, 34 genera and 77 species of PPNs were identified. The highest diversity was found in Helicotylenchus genus, with six species previously reported in Spain and with H. oleae being a first report. Neodolichorhynchus microphasmis and Diptenchus sp., Diphtherophora sp., and Discotylenchus sp., usually considered fungal feeders, were also reported for the first time associated to olive rhizosphere. PPNs abundance ranged from 66 to 16,288 individuals/500-cm3 of soil with Helicotylenchus digonicus being the most prevalent species, followed by Filenchus sp., Merlinius brevidens and Xiphinema pachtaicum. Nematode abundance and diversity indexes were influenced by olive cultivar, and orchard and soil management practices; while olive variety and soil texture were the main factors driving PPN community composition. Soil physicochemical properties and climatic characteristics most strongly associated to the PPN community composition included pH, sand content and exchangeable K, and maximum and minimum average temperature of the sampled locations. Our data suggests that there is a high diversity of PPNs associated to olive in Southern Spain that can exert different damage to olive roots depending on the olive variety and their abundance. Further analysis to determine the resistance levels of most common olive varieties to the prevalent PPNs in Spain will help to choose the most appropriate ones for the establishment of new plantations. This choice will take into consideration the specific

  18. Soil Properties and Olive Cultivar Determine the Structure and Diversity of Plant-Parasitic Nematode Communities Infesting Olive Orchards Soils in Southern Spain

    Science.gov (United States)

    Palomares-Rius, Juan E.; Castillo, Pablo; Montes-Borrego, Miguel; Navas-Cortés, Juan A.; Landa, Blanca B.

    2015-01-01

    This work has studied for the first time the structure and diversity of plant-parasitic nematodes (PPNs) infesting olive orchard soils in a wide-region in Spain that included 92 locations. It aims at determining which agronomical or environmental factors associated to the olive orchards are the main drivers of the PPNs community structure and diversity. Classical morphological and morphometric identification methods were used to determine the frequency and densities of PPNs. Thirteen families, 34 genera and 77 species of PPNs were identified. The highest diversity was found in Helicotylenchus genus, with six species previously reported in Spain and with H. oleae being a first report. Neodolichorhynchus microphasmis and Diptenchus sp., Diphtherophora sp., and Discotylenchus sp., usually considered fungal feeders, were also reported for the first time associated to olive rhizosphere. PPNs abundance ranged from 66 to 16,288 individuals/500-cm3 of soil with Helicotylenchus digonicus being the most prevalent species, followed by Filenchus sp., Merlinius brevidens and Xiphinema pachtaicum. Nematode abundance and diversity indexes were influenced by olive cultivar, and orchard and soil management practices; while olive variety and soil texture were the main factors driving PPN community composition. Soil physicochemical properties and climatic characteristics most strongly associated to the PPN community composition included pH, sand content and exchangeable K, and maximum and minimum average temperature of the sampled locations. Our data suggests that there is a high diversity of PPNs associated to olive in Southern Spain that can exert different damage to olive roots depending on the olive variety and their abundance. Further analysis to determine the resistance levels of most common olive varieties to the prevalent PPNs in Spain will help to choose the most appropriate ones for the establishment of new plantations. This choice will take into consideration the specific

  19. Occurrence of entomopathogenic fungi and parasitic nematodes on Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae collected in Central Chiapas, Mexico

    Science.gov (United States)

    Fall armyworm larvae (FAW), Spodoptera frugiperda (J. E. Smith) were collected from whorl-stage cornfields, between the V2 and V4 stages, in 22 localities of Central, Chiapas, México, called "La Frailesca" during late June 2009 to determine the occurrence of native entomopathogens and parasitic nema...

  20. Complete genome sequence of Bacillus thuringiensis YC-10, a novel active strain against plant-parasitic nematodes.

    Science.gov (United States)

    Cheng, Feixue; Wang, Jian; Song, Zhiqiang; Cheng, Ju'e; Zhang, Deyong; Liu, Yong

    2015-09-20

    Bacillus thuringiensis is an important microbial biopesticide for controlling agricultural pests by the production of toxic parasporal crystals proteins.Here,we report the finished annotated genome sequence of B. thuringiensis YC-10,which is highly toxic to nematodes.The complete genome sequence consists of a circular chromosome and nine circular plasmids,which the biggest plasmid harbors six parasporal crystals proteins genes consisting of cry1Aa, cry1Ac, cry1Ia, cry2Aa, cry2Ab and cryB1. The crystals proteins of Cry1Ia and Cry1Aa have high nematicidal activity against Meloidogyne incognita. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Behavioural adaptations of argulid parasites (Crustacea: Branchiura) to major challenges in their life cycle.

    Science.gov (United States)

    Mikheev, V N; Pasternak, A F; Valtonen, E T

    2015-07-25

    Fish lice (Argulus spp.) are obligate ectoparasites, which contrary to most aquatic parasites, retain the ability to swim freely throughout the whole of their life. In fish farms, they can quickly increase in numbers and without effective control cause argulosis, which results in the reduced growth and survival of their fish hosts. The morphology of Argulus spp, including their sensory organs, is suitable for both parasitism and free-swimming. By spending a considerable amount of time away from their host, these parasites risk being excessively dispersed, which could endanger mating success. Here we present a review of recent studies on the behaviour of Argulus spp, especially the aggregative behaviour that mitigates the dilution of the parasite population. Aggregation of parasites, which is especially important during the period of reproduction, occurs on different scales and involves both the aggregation of the host and the aggregation of the parasites on the host. The main behavioural adaptations of Argulus spp, including searches for hosts and mates, host manipulation and host choice, are all focused on the fish. As these ectoparasites repeatedly change hosts and inflict skin damage, they can act as vectors for fish pathogens. The development of environmentally friendly measures for the control and prevention of argulosis needs to take into account the behaviour of the parasites.

  2. Genome sequencing of chimpanzee malaria parasites reveals possible pathways of adaptation to human hosts

    KAUST Repository

    Otto, Thomas D.

    2014-09-09

    Plasmodium falciparum causes most human malaria deaths, having prehistorically evolved from parasites of African Great Apes. Here we explore the genomic basis of P. falciparum adaptation to human hosts by fully sequencing the genome of the closely related chimpanzee parasite species P. reichenowi, and obtaining partial sequence data from a more distantly related chimpanzee parasite (P. gaboni). The close relationship between P. reichenowi and P. falciparum is emphasized by almost complete conservation of genomic synteny, but against this strikingly conserved background we observe major differences at loci involved in erythrocyte invasion. The organization of most virulence-associated multigene families, including the hypervariable var genes, is broadly conserved, but P. falciparum has a smaller subset of rif and stevor genes whose products are expressed on the infected erythrocyte surface. Genome-wide analysis identifies other loci under recent positive selection, but a limited number of changes at the host–parasite interface may have mediated host switching.

  3. A Genome Resequencing-Based Genetic Map Reveals the Recombination Landscape of an Outbred Parasitic Nematode in the Presence of Polyploidy and Polyandry.

    Science.gov (United States)

    Doyle, Stephen R; Laing, Roz; Bartley, David J; Britton, Collette; Chaudhry, Umer; Gilleard, John S; Holroyd, Nancy; Mable, Barbara K; Maitland, Kirsty; Morrison, Alison A; Tait, Andy; Tracey, Alan; Berriman, Matthew; Devaney, Eileen; Cotton, James A; Sargison, Neil D

    2018-02-01

    The parasitic nematode Haemonchus contortus is an economically and clinically important pathogen of small ruminants, and a model system for understanding the mechanisms and evolution of traits such as anthelmintic resistance. Anthelmintic resistance is widespread and is a major threat to the sustainability of livestock agriculture globally; however, little is known about the genome architecture and parameters such as recombination that will ultimately influence the rate at which resistance may evolve and spread. Here, we performed a genetic cross between two divergent strains of H. contortus, and subsequently used whole-genome resequencing of a female worm and her brood to identify the distribution of genome-wide variation that characterizes these strains. Using a novel bioinformatic approach to identify variants that segregate as expected in a pseudotestcross, we characterized linkage groups and estimated genetic distances between markers to generate a chromosome-scale F1 genetic map. We exploited this map to reveal the recombination landscape, the first for any helminth species, demonstrating extensive variation in recombination rate within and between chromosomes. Analyses of these data also revealed the extent of polyandry, whereby at least eight males were found to have contributed to the genetic variation of the progeny analyzed. Triploid offspring were also identified, which we hypothesize are the result of nondisjunction during female meiosis or polyspermy. These results expand our knowledge of the genetics of parasitic helminths and the unusual life-history of H. contortus, and enhance ongoing efforts to understand the genetic basis of resistance to the drugs used to control these worms and for related species that infect livestock and humans throughout the world. This study also demonstrates the feasibility of using whole-genome resequencing data to directly construct a genetic map in a single generation cross from a noninbred nonmodel organism with a

  4. Stage-specific excretory-secretory small heat shock proteins from the parasitic nematode Strongyloides ratti--putative links to host's intestinal mucosal defense system.

    Science.gov (United States)

    Younis, Abuelhassan Elshazly; Geisinger, Frank; Ajonina-Ekoti, Irene; Soblik, Hanns; Steen, Hanno; Mitreva, Makedonka; Erttmann, Klaus D; Perbandt, Markus; Liebau, Eva; Brattig, Norbert W

    2011-09-01

    In a search for molecules involved in the interaction between intestinal nematodes and mammalian mucosal host cells, we performed MS to identify excretory-secretory proteins from Strongyloides ratti. In the excretory-secretory proteins of the parasitic female stage, we detected, in addition to other peptides, peptides homologous with the Caenorhabditis elegans heat shock protein (HSP)-17, named Sra-HSP-17.1 (∼ 19 kDa) and Sra-HSP-17.2 (∼ 18 kDa), with 49% amino acid identity. The full-length cDNAs (483 bp and 474 bp, respectively) were identified, and the genomic organization was analyzed. To allow further characterization, the proteins were recombinantly expressed and purified. Profiling of transcription by quantitative real-time-PCR and of protein by ELISA in various developmental stages revealed parasitic female-specific expression. Sequence analyses of both the DNA and amino acid sequences showed that the two proteins share a conserved α-crystallin domain and variable N-terminals. The Sra-HSP-17s showed the highest homology with the deduced small HSP sequence of the human pathogen Strongyloides stercoralis. We observed strong immunogenicity of both proteins, leading to strong IgG responses following infection of rats. Flow cytometric analysis indicated the binding of Sra-HSP-17s to the monocyte-macrophage lineage but not to peripheral lymphocytes or neutrophils. A rat intestinal epithelial cell line showed dose-dependent binding to Sra-HSP-17.1, but not to Sra-HSP-17.2. Exposed monocytes released interleukin-10 but not tumor necrosis factor-α in response to Sra-HSP-17s, suggesting the possible involvement of secreted female proteins in host immune responses. © 2011 The Authors Journal compilation © 2011 FEBS.

  5. Analysis of the genetic diversity of the nematode parasite Baylisascaris schroederi from wild giant pandas in different mountain ranges in China.

    Science.gov (United States)

    Zhou, Xuan; Xie, Yue; Zhang, Zhi-he; Wang, Cheng-dong; Sun, Yun; Gu, Xiao-bin; Wang, Shu-xian; Peng, Xue-rong; Yang, Guang-you

    2013-08-08

    Baylisascaris schroederi is one of the most common nematodes of the giant panda, and can cause severe baylisascarosis in both wild and captive giant pandas. Previous studies of the giant pandas indicated that this population is genetically distinct, implying the presence of a new subspecies. Based on the co-evolution between the parasite and the host, the aim of this study was to investigate the genetic differentiation in the B. schroederi population collected from giant pandas inhabiting different mountain ranges, and further to identify whether the evolution of this parasite correlates with the evolution of giant pandas. In this study, 48 B. schroederi were collected from 28 wild giant pandas inhabiting the Qinling, Minshan and Qionglai mountain ranges in China. The complete sequence of the mitochondrial cytochrome b (mtCytb) gene was amplified by PCR, and the corresponding population genetic diversity of the three mountain populations was determined. In addition, we discussed the evolutionary relationship between B. schroederi and its host giant panda. For the DNA dataset, insignificant Fst values and a significant, high level of gene flow were detected among the three mountain populations of B. schroederi, and high genetic variation within populations and a low genetic distance were observed. Both phylogenetic analyses and network mapping of the 16 haplotypes revealed a dispersed pattern and an absence of branches strictly corresponding to the three mountain range sampling sites. Neutrality tests and mismatch analysis indicated that B. schroederi experienced a population expansion in the past. Taken together, the dispersed haplotype map, extremely high gene flow among the three populations of B. schroederi, low genetic structure and rapid evolutionary rate suggest that the B. schroederi populations did not follow a pattern of isolation by distance, indicating the existence of physical connections before these populations became geographically separated.

  6. Nematóides que parasitam a soja na região de Bauru Nematode parasites of soybean in the Bauru region

    Directory of Open Access Journals (Sweden)

    Luiz Gonzaga E. Lordello

    1956-01-01

    Full Text Available Entre os sérios fatôres que atuam contra a expansão da cultura da soja no Estado de São Paulo, acha-se o representado por nematóides parasitos. Dêstes, os que mais têm atraído a atenção dos cultivadores e fitopatologistas são as espécies formadoras de galhas no sistema radicular (Meloidogyne spp.. O estudo do material atacado coligido em Bauru revelou que, naquela região, três formas se acham envolvidas, a saber : Pratylenchus sp., Meloidogyne incognita (Kofoid & White, 1919 Chitwood, 1949 e M. javanica bauruensis n. subsp. Neste trabalho é estudada a nova subespécie, sendo também apresentadas algumas observações sobre a população de M. incognita.One of the serious detriments to soybean (Glycine max (L. Merr. cultivation in the State of S. Paulo, Brazil, are root-parasitic nematodes. A study of infected material collected at Bauru, where at least two distinct soybean varieties were cultivated, disclosed that three forms were involved: a meadow nematode (Pralylenchus sp. and two root-knot nematodes (Meloidogyne incognita (Kofoid & White, 1919 Chitwood, 1949, and M. javanica bauruensis n. subsp.. Silva, Lordello & Miyasaka (3 published some observations about the resistance of several soybean varieties to the attacks by root-knot nematodes in Campinas. A detailed study of the nematodes involved in those experiments, which were considered as related do M. incognita, has not yet been made. One of the varieties tested, La 41-1219, proved to be resistant, thereby providing promising material for further studies and breeding. Unfortunately, such a variety when planted in Bauru, was severely attacked by a root-knot species, which is identified as M. incognita. Attacks by M. javanica bauruensis was not noted in that variety but was noted in another variety (Abura growing adjacent in the same field. The host preference of those two nematodes was specific and very marked. M. incognita attacked only var. La 41-1219 and M. javanica

  7. Biochar-enhanced composts reduce the potential leaching of nutrients and heavy metals and suppress plant-parasitic nematodes in excessively fertilized cucumber soils.

    Science.gov (United States)

    Cao, Yune; Gao, Yanming; Qi, Yanbin; Li, Jianshe

    2018-03-01

    Excessive fertilization is a common agricultural practice that has largely reduced soil nutrient retention capacity and led to nutrient leaching in China. To reduce nutrient leaching, in this study, we evaluated the application of biochar, compost, and biochar-compost on soil properties, leaching water quality, and cucumber plant growth in soils with different nutrient levels. In general, the concentrations of nutrients and heavy metals in leaching water were higher under high-nutrient conditions than under low-nutrient conditions. Both biochar and compost efficiently enhanced soil cation exchange capacity (CEC), water holding capacity (WHC), and microbial biomass carbon (MBC), nitrogen (MBN), and phosphorus (MBP), reduced the potential leaching of nutrients and heavy metals, and improved plant growth. The efficiency of biochar and compost in soil CEC, WHC, MBC, MBN, and MBP and plant growth was enhanced when applied jointly. In addition, biochar and biochar-enhanced compost efficiently suppressed plant-parasitic nematode infestation in a soil with high levels of both N and P. Our results suggest that biochar-enhanced compost can reduce the potential environmental risks in excessively fertilized vegetable soils.

  8. Two new species of nematode parasites, Cucullanus epinepheli sp. n. (Cucullanidae) and Procamallanus (Spirocamallanus) sinespinis sp. n. (Camallanidae), from marine serranid and haemulid fishes off New Caledonia.

    Science.gov (United States)

    Moravec, Frantisek; Justine, Jean-Lou

    2017-04-05

    Based on light and scanning electron microscopical studies, two new species of parasitic nematodes are described from marine perciform fishes off New Caledonia: Cucullanus epinepheli sp. n. (Cucullanidae) from the intestine of the brownspotted grouper Epinephelus chlorostigma (Valenciennes) (Serranidae) and Procamallanus (Spirocamallanus) sinespinis sp. n. from the intestine of the silver grunt Pomadasys argenteus (Forsskål) (Haemulidae). Cucullanus epinepheli sp. n. differs from its congeners mainly in possessing a unique structure of the anterior, elevated cloacal lip with a large posterior outgrowth covering the cloacal aperture and in the presence of cervical alae and two small preanal papillae on the median dome-shaped precloacal elevation. This is the second known nominal species of this genus parasitising fishes of the family Serranidae and the second representative of Cucullanus Müller, 1777 recorded from fishes in New Caledonian waters. Procamallanus (Spirocamallanus) sinespinis sp. n. is mainly characterised by 10-12 spiral ridges in the buccal capsule, the presence of wide caudal alae, three pairs of pedunculate preanal papillae, two unequally long spicules (465-525 µm and 218-231 µm) and by the tail tip with a knob-like structure in the male, and the broad, rounded tail with a terminal digit-like protrusion without cuticular spikes in the female. This is the fifth nominal species of the subgenus Spirocamallanus Olsen, 1952 reported from fishes in New Caledonian waters.

  9. Effect of changes in the nutritional status on the performances of growing Creole kids during an established nematode parasite infection.

    Science.gov (United States)

    Ceï, W; Archimède, H; Arquet, R; Félicité, Y; Feuillet, D; Nepos, A; Mulciba, P; Etienne, T; Alexandre, G; Bambou, J C

    2017-04-01

    In this study, we evaluated the effect of changes in the nutritional status on the performances of growing Creole kids during an established experimental gastrointestinal nematode (GIN) infection. Eighteen 6-month-old Creole kids were distributed in two main groups infected (I) and non-infected (NI) and were placed for a period of 4 weeks on each of three diets differing in their nutritional values: (1) fresh grass (FG, 6.7 MJ/kg dry matter (DM) and 7.9% crude protein (CP)) non-supplemented, (2) FG supplemented with a commercial concentrate (CC, 12.2 MJ/kg DM and 20.6% of CP), and (3) FG supplemented with dried banana (Ban, 11.1 MJ/kg DM and 4.3% CP). The experiment was designed as a split-plot with experimental infection (I and NI) as the main plot and the diets (FG, CC, and Ban) as the subplots with three replicates. We showed a significant effect of the diet changes on the fecal egg counts. A higher dry matter intake, digestibility, and growth rate were observed with the CC diet but together with a slight but significant increase of the intensity of the GIN infection. These data suggest that the improvement of the protein nutritional status during an establish GIN infection would improve the animal performance at the expense of the mechanism involved in the control of the infection.

  10. Identification of Virulence Factors in Nematode-Trapping Fungi - Insights from Genomics, Transcriptomics and Proteomics

    OpenAIRE

    Andersson, Karl-Magnus

    2013-01-01

    Nematode-trapping fungi are soil-living organisms with the unique ability to capture and infect free-living nematodes. The interest in studying these fungi arises from their potential use as biological control agents for plant- and animal-parasitic nematodes. To enter the parasitic stage, nematode-trapping fungi develop different kinds of trapping structures. In order to understand more about the evolution of parasitism in the nematode-trapping fungi and to identify virulence factors in these...

  11. effect of gamma radiation and parasitic nematodes on the black cut-worm agrotis ipsilon(HUFN)

    International Nuclear Information System (INIS)

    Sileem, T.M.

    2011-01-01

    The sterility effects were examined on the P1 generation of the black cutworm; Agrotis ipsilon (Hufn.) after gamma sterilization with at 0, 75, 100,125, 150,175 and 200 Gy, to identify the dose of gamma irradiation that would allow for maximum production of partially sterile P1 adults while inducing full sterility in the F1 generation. The studied effects were included the percentage mated males with untreated females, copulation duration to format spermatophores directly in the female bursa copulatrix, number of eggs /female deposited by females mated to irradiated males and egg hatch through three sequential females.The irradiated males with tested doses as well as untreated control were tested for mating successive and starting copulation at the same period of the scotophase. The mating competitiveness calculated from the direct observation in A. ipsilon males emerged from pupae irradiated at doses 75 to 200 Gy was noticed. The effect of substerilizing dose (125Gy) on certain biological aspects and reproduction was studied among parental generation, as well as immature stages were investigated throughout two successive generations. The influence of two entomopathogenic nematodes, Steinernema carpocapsae and Steinernema riobrivae on the insect management was included. Special attention was given to combined effect of F1 progeny of partially sterile males and S. Carpocapsae (All) on A .ipsilon, the combination of tested treatments at all concentrations analyzed for synergistic effect. The parasitisation efficacy of EPNs, the morbidity and mortality induced by normal IJs (i.e., IJs derived from untreated host) and the incubation time taken by normal IJs were compared with these of IJs derived from irradiated host with 125 Gy

  12. Shifting from priming of salicylic acid- to jasmonic acid-regulated defences by Trichoderma protects tomato against the root knot nematode Meloidogyne incognita.

    Science.gov (United States)

    Martínez-Medina, Ainhoa; Fernandez, Ivan; Lok, Gerrit B; Pozo, María J; Pieterse, Corné M J; Van Wees, Saskia C M

    2017-02-01

    Beneficial root endophytes such as Trichoderma spp. can reduce infections by parasitic nematodes through triggering host defences. Little is currently known about the complex hormone signalling underlying the induction of resistance. In this study, we investigated whether Trichoderma modulates the hormone signalling network in the host to induce resistance to nematodes. We investigated the role and the timing of the jasmonic acid (JA)- and salicylic acid (SA)-regulated defensive pathways in Trichoderma-induced resistance to the root knot nematode Meloidogyne incognita. A split-root system of tomato (Solanum lycopersicum) was used to study local and systemic induced defences by analysing nematode performance, defence gene expression, responsiveness to exogenous hormone application, and dependence on SA and JA signalling of Trichoderma-induced resistance. Root colonization by Trichoderma impeded nematode performance both locally and systemically at multiple stages of the parasitism, that is, invasion, galling and reproduction. First, Trichoderma primed SA-regulated defences, which limited nematode root invasion. Then, Trichoderma enhanced JA-regulated defences, thereby antagonizing the deregulation of JA-dependent immunity by the nematodes, which compromised galling and fecundity. Our results show that Trichoderma primes SA- and JA-dependent defences in roots, and that the priming of responsiveness to these hormones upon nematode attack is plastic and adaptive to the parasitism stage. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  13. Different responses of soybean cyst nematode resistance between ...

    Indian Academy of Sciences (India)

    YONGCHUN LI

    parasitic nematode that feeds on the roots of soybean and most economically ... sified pest problems (Skorupska et al. 1994). Soybean cyst nematode .... Genomic DNA extraction and pooling for bulk segregant analysis. Genomic DNA was isolated ...

  14. First report of nematode parasites of Physalaemus santafecinus (Anura: Leiuperidae from Corrientes, Argentina Primer registro de nematodos parásitos de Physalaemus santafecinus (Anura: Leiuperidae de Corrientes, Argentina

    Directory of Open Access Journals (Sweden)

    Cynthya Elizabeth González

    2010-12-01

    Full Text Available One hundred and eighty-three nematodes were recovered from 81 adults of leiuperid Physalaemus santafecinus examined from Corrientes, Argentina captured between January 2002 and December 2003. A total of 3 adults nematode species (Cosmocerca podicipinus, Cosmocerca parva, Aplectana hylambatis and 1 larval species (Physaloptera sp. were obtained. We present morphological characters, metric information and range for these nematode species and compared these with other specimens collected from different hosts of the Neotropical Realm. This is the first report of nematode parasites of P. santafecinus from Argentina.Ciento ochenta y tres nematodos fueron recolectados de 81 adultos del leiupérido Physalaemus santafecinus examinados en Corrientes, Argentina y capturados entre enero del 2002 y diciembre del 2003. Estos nematodos pertenecen a un total de 4 especies, 3 en estado adulto: Cosmocerca podicipinus, Cosmocerca parva, Aplectana hylambatis, y 1 especie en estado larval, Physaloptera sp. Se presentan características morfológicas, información métrica e intervalos de medidas de estas especies de nematodos, comparándolas con ejemplares recolectados de diferentes hospederos de la región neotropical. Éste es el primer registro de nematodos parásitos para P. santafecinus de Argentina.

  15. Complex adaptive responses during antagonistic coevolution between Tribolium castaneum and its natural parasite Nosema whitei revealed by multiple fitness components

    Directory of Open Access Journals (Sweden)

    Bérénos Camillo

    2012-01-01

    Full Text Available Abstract Background Host-parasite coevolution can lead to local adaptation of either parasite or host if there is specificity (GxG interactions and asymmetric evolutionary potential between host and parasite. This has been demonstrated both experimentally and in field studies, but a substantial proportion of studies fail to detect such clear-cut patterns. One explanation for this is that adaptation can be masked by counter-adaptation by the antagonist. Additionally, genetic architecture underlying the interaction is often highly complex thus preventing specific adaptive responses. Here, we have employed a reciprocal cross-infection experiment to unravel the adaptive responses of two components of fitness affecting both parties with different complexities of the underlying genetic architecture (i.e. mortality and spore load. Furthermore, our experimental coevolution of hosts (Tribolium castaneum and parasites (Nosema whitei included paired replicates of naive hosts from identical genetic backgrounds to allow separation between host- and parasite-specific responses. Results In hosts, coevolution led to higher resistance and altered resistance profiles compared to paired control lines. Host genotype × parasite genotype interactions (GH × GP were observed for spore load (the trait of lower genetic complexity, but not for mortality. Overall parasite performance correlated with resistance of its matching host coevolution background reflecting a directional and unspecific response to strength of selection during coevolution. Despite high selective pressures exerted by the obligatory killing parasite, and host- and parasite-specific mortality profiles, no general pattern of local adaptation was observed, but one case of parasite maladaptation was consistently observed on both coevolved and control host populations. In addition, the use of replicate control host populations in the assay revealed one case of host maladaptation and one case of parasite

  16. Self-medication as adaptive plasticity: increased ingestion of plant toxins by parasitized caterpillars.

    Directory of Open Access Journals (Sweden)

    Michael S Singer

    Full Text Available Self-medication is a specific therapeutic behavioral change in response to disease or parasitism. The empirical literature on self-medication has so far focused entirely on identifying cases of self-medication in which particular behaviors are linked to therapeutic outcomes. In this study, we frame self-medication in the broader realm of adaptive plasticity, which provides several testable predictions for verifying self-medication and advancing its conceptual significance. First, self-medication behavior should improve the fitness of animals infected by parasites or pathogens. Second, self-medication behavior in the absence of infection should decrease fitness. Third, infection should induce self-medication behavior. The few rigorous studies of self-medication in non-human animals have not used this theoretical framework and thus have not tested fitness costs of self-medication in the absence of disease or parasitism. Here we use manipulative experiments to test these predictions with the foraging behavior of woolly bear caterpillars (Grammia incorrupta; Lepidoptera: Arctiidae in response to their lethal endoparasites (tachinid flies. Our experiments show that the ingestion of plant toxins called pyrrolizidine alkaloids improves the survival of parasitized caterpillars by conferring resistance against tachinid flies. Consistent with theoretical prediction, excessive ingestion of these toxins reduces the survival of unparasitized caterpillars. Parasitized caterpillars are more likely than unparasitized caterpillars to specifically ingest large amounts of pyrrolizidine alkaloids. This case challenges the conventional view that self-medication behavior is restricted to animals with advanced cognitive abilities, such as primates, and empowers the science of self-medication by placing it in the domain of adaptive plasticity theory.

  17. Proteins secreted by root-knot nematodes accumulate in the extracellular compartment during root infection.

    Science.gov (United States)

    Rosso, Marie-Noëlle; Vieira, Paulo; de Almeida-Engler, Janice; Castagnone-Sereno, Philippe

    2011-08-01

    Root-knot nematodes are biotrophic parasites that invade the root apex of host plants and migrate towards the vascular cylinder where they induce the differentiation of root cells into hypertrophied multinucleated giant cells. Giant cells are part of the permanent feeding site required for nematode development into the adult stage. To date, a repertoire of candidate effectors potentially secreted by the nematode into the plant tissues to promote infection has been identified. However, the precise role of these candidate effectors during root invasion or during giant cell induction and maintenance remains largely unknown. Primarily, the identification of the destination of nematode effectors within plant cell compartment(s) is crucial to decipher their actual functions. We analysed the fine localization in root tissues of five nematode effectors throughout the migratory and sedentary phases of parasitism using an adapted immunocytochemical method that preserves host and pathogen tissues.  We showed that secretion of effectors from the amphids or the oesophageal glands is tightly regulated during the course of infection. The analysed effectors accumulated in the root tissues along the nematode migratory path and along the cell wall of giant cells, showing the apoplasm as an important destination compartment for these effectors during migration and feeding cell formation.

  18. Nematode cholinergic pharmacology

    Energy Technology Data Exchange (ETDEWEB)

    Segerberg, M.A.

    1989-01-01

    Nematode acetylcholine (ACh) receptors were characterized using both biochemical and electrophysiological techniques, including: (1) receptor binding studies in crude homogenates of the free-living nematode Caenorhabditis elegans and the parasitic nematode Ascaris lumbricoides with the high-affinity probe ({sup 3}H)N-methylscopolamine (({sup 3}H)NMS) which binds to muscarinic receptors in many vertebrate and invertebrate tissues (2) measurement of depolarization and contraction induced by a variety of cholinergic agents, including N-methylscopolamine (NMS), in an innervated dorsal muscle strip preparation of Ascaris; (3) examination of the antagonistic actions of d-tubocurarine (dTC) and NMS at dorsal neuromuscular junction; (4) measurement of input resistance changes in Ascaris commissural motorneurons induced by ACh, dTC, NMS, pilocarpine and other cholinergic drugs.

  19. The many roads to parasitism: a tale of convergence.

    Science.gov (United States)

    Poulin, Robert

    2011-01-01

    Parasitic organisms account for a large portion of living species. They have arisen on multiple independent occasions in many phyla, and thus encompass a huge biological diversity. This review uses several lines of evidence to argue that this vast diversity can be reduced to a few evolutionary end points that transcend phylogenetic boundaries. These represent peaks in the adaptive landscape reached independently by different lineages undergoing convergent evolution. Among eukaryotic parasites living in or on animals, six basic parasitic strategies are identified based on the number of hosts used per parasite generation, the fitness loss incurred by the host, and the transmission routes used by the parasites. They are parasitoids, parasitic castrators, directly transmitted parasites, trophically transmitted parasites, vector-transmitted parasites and micropredators. These show evidence of convergence in morphology, physiology, reproduction, life cycles and transmission patterns. Parasite-host body size ratios, and the relationship between virulence and intensity of infection, are also associated with the different parasitic strategies, but not consistently so. At the population level, patterns of parasite distribution among hosts are not uniform across all parasitic strategies, but are distinctly different for parasitoids and castrators than for other parasites. To demonstrate that the above six strategies defined for animal parasites are universal, comparisons are made with parasites of plants, in particular, plant-parasitic nematodes and parasitic angiosperms; these are shown to follow the same evolutionary trajectories seen among animal parasites, despite huge physiological and ecological differences between animals and plants. Beyond demonstrating the inevitable convergence of disparate lineages across biological hyperspace towards a limited set of adaptive strategies, this synthesis also provides a unifying framework for the study of parasitism. Copyright

  20. In-vitro predatory activity of nematophagous fungi from Costa Rica with potential use for controlling sheep and goat parasitic nematodes

    Directory of Open Access Journals (Sweden)

    Natalia Soto-Barrientos

    2011-03-01

    Full Text Available In tropical and subtropical regions of the world, parasitic diseases are a main cause of losses in livestock productivity. The increased acquired resistence to anthelmintics by gastrointestinal nematodes, requires biological control be considered as a potential feasible and effective alternative. The most effective natural soil enemies of nematodes are nematophagous fungi. In order to collect and identify predator nematophagous fungi (PNF, samples were obtained from 51 farms distributed throughout the seven provinces of Costa Rica. The origin samples included: soil from different crops (potatoes, tomatoes, bananas, ornamental plants, squash and coffee; animal feces (cattle, sheep, goat and horse; soil and fallen leaves from forest; and plants with signs of nematode infection. Each sample was processed using three techniques for the extraction of fungi from soil: sprinkling technique, soil dilution and humidity chamber. Twenty four strains of nematophagous fungi were found in 19 farms; 83.3% of the fungi were isolated by sprinkling technique. The following fungi were idenified: Arthrobotrys oligospora (n=13; Candelabrella musiformis (n=9; and for the first time there was isolation of A. conoides (n=1 and A. dactyloides (n=1 in the country. Moreover, 16 strains from Trichoderma (n=13, Beauveria (n=1, Clonostachys (n=1 and Lecanicillium (n=1 were obtained. In addition, pH of each possible fungal isolation source was measured, and it varied from 5.2 to 9.9, however PNF isolates fell within the range of 5.6 to 7.5. The PNF strains were cultivated in four different media for the production of chhlamydospores: potato dextrose agar (PDA; corn meal agar (CMA; malt extract agar (MEA and potato carrot agar (PCA. Out of these cultures, 95.8% of the strains formed chlamydospores primarily in the PCA. Of these strains, the profilic spore producers were subjected to ruminant artificial gastrointestinal conditions. A total of 14 fungi were tested, out of which

  1. Control of bovine gastrointestinal nematode parasites using pellets of the nematode-trapping fungus Monacrosporium thaumasium Controle de nematóides parasitos gastrintestinais de bovinos com pellets do fungo predador de nematóides Monacrosporium thaumasium

    Directory of Open Access Journals (Sweden)

    Jackson Victor de Araújo

    2004-04-01

    Full Text Available The viability of a formulation of the fungus Monacrosporium thaumasium associated with ivermectin was evaluated for the biological control of bovine gastrointestinal nematode parasites. Four groups of five calves each were placed in pastures with a stocking rate of 1.6 animal/hectare. In group 1 (control, the calves did not receive any treatment. In group 2, each animal received 20g of pellets of M. thaumasium orally twice a week during a six-month period that began with the onset of the rainy season (October 23, 2000. In group 3, each animal received 20g of pellets of M. thaumasium orally twice a week during the same period as 2, as well as two strategic treatments with ivermectin (200 mcg/kg on May 10, 2001 and July 5, 2001. In group 4, the animals were treated with ivermectin alone as described for group 3. EPG counts for group 1 were significantly greater (PA viabilidade de uma formulação do fungo Monacrosporium thaumasium associada com ivermectina foi avaliada no controle biológico de nematóides parasitos gastrintestinais de bovinos. Quatro grupos de cinco bezerros foram colocados em pastagens com uma taxa de lotação de 1,6 animal/hectare. No grupo 1 (controle, os bezerros não receberam nenhum tratamento. No grupo 2, cada animal recebeu 20 g de pellets de M. thaumasium, via oral, duas vezes por semana e durante um período de seis meses que começou na estação chuvosa (23 de outubro, 2000. No grupo 3, cada animal recebeu 20g de pellets de M. thaumasium, via oral, duas vezes por semana e durante o mesmo período do grupo 2, assim como dois tratamentos estratégicos com ivermectina (200 mcg/kg em 10 de maio de 2001 e em 5 de julho de 2001. No grupo 4, os animais foram tratados somente com ivermectina como descrito no grupo 3. As contagens de OPG dos animais do grupo 1 foram significativamente maiores (P< 0,01 do que os animais dos grupos 2 e 3 e a diferença no final do experimento foi próxima de 100%. Os OPGs dos animais do grupo 4

  2. Phylogeny of nematodes from birds of prey

    OpenAIRE

    Honisch, Michaela

    2010-01-01

    Birds of prey host a wide variety of endoparasites. The majority of these endoparasites are nematodes. They can be found mainly in the digestive and respiratory system. The current accepted phylogeny of nematodes found in birds of prey is based on morphological traits. In this study molecular data were used to assess phylogenetic relationships in this group of parasitic nematodes. The aim of the study was to evaluate a method for rapid species identification, to construct a phylogeny of paras...

  3. [Morphological adaptations of acariform mites (Acari: Acariformes) to permanent parasitism on mammals].

    Science.gov (United States)

    Bochkov, A V

    2007-01-01

    The external morphological adaptations to parasitism in acariform mites (Acari: Acariformes), permanently parasiting mammals, are briefly summated and analyzed. According to several external morphological criteria (structures of gnathosoma, idiosoma, setation, legs and life cycle), the following six morphoecotypes were established: skin mites (i)-- Cheyletidae, Chirorhynchobiidae, Lobalgidae, Myobiidae, Myocoptidae (the most part), Rhyncoptidae, Psoroptidae; fur mites (ii)--Atopomelidae, Clirodiscidae, Listrophoridae, Myocoptidae (Trichoecius only); skin burrowing mites (iii)--Sarcoptidae; intradermal mites (iv) - sorergatidae and Demodicidae; interstitial mites (v) - pimyodicidae; respiratory mites (vi) - reynetidae, Gastronyssidae, Lemurnyssidae, Pneumocoptidae. In the case of prostigmatic mites, the detailed reconstruction of the origin and evolution of "parasitic" morphoecotypes is possible due to the tentative phylogenetic hypotheses, which were proposed for the infraorder Eleutherengon, a, including the most part of the permanent mammalian parasites among prostigmatic mites (Kethley in Norton, 1993; Bochkov, 2002). The parasitism of Speleognathinae (Ereynetidae) in the mammalian respiratory tract arose independently of the other prostigmats. It is quite possible that these mites switched on mammals from birds, because they are more widely represented on these hosts than on mammals. The prostigmatic parasitism on mammalian skin seems to be originated independently in myobiids, in the five cheyletid tribes, Cheyletiellini, Niheliini, and Teinocheylini, Chelonotini, Cheyletini, and, probably, in a cheyletoid ansector of the sister families Psorergatidae-Demodicidae (Bochkov, Fain, 2001; Bochkov, 2002). Demodicids and psorergatids developed adaptations to parasitism in the skin gland ducts and directly in the epithelial level, respectively in the process of the subsequent specialization. Mites of the family Epimyodicidae belong to the phylogenetic line

  4. Microbial ecology and nematode control in natural ecosystems

    NARCIS (Netherlands)

    Costa, S.R.; Van der Putten, W.H.; Kerry, B.R.

    2011-01-01

    Plant-parasitic nematodes have traditionally been studied in agricultural systems, where they can be pests of importance on a wide range of crops. Nevertheless, nematode ecology in natural ecosystems is receiving increasing interest because of the role of nematodes in soil food webs, nutrient

  5. Consistent pattern of local adaptation during an experimental heat wave in a pipefish-trematode host-parasite system.

    Directory of Open Access Journals (Sweden)

    Susanne H Landis

    Full Text Available Extreme climate events such as heat waves are expected to increase in frequency under global change. As one indirect effect, they can alter magnitude and direction of species interactions, for example those between hosts and parasites. We simulated a summer heat wave to investigate how a changing environment affects the interaction between the broad-nosed pipefish (Syngnathus typhle as a host and its digenean trematode parasite (Cryptocotyle lingua. In a fully reciprocal laboratory infection experiment, pipefish from three different coastal locations were exposed to sympatric and allopatric trematode cercariae. In order to examine whether an extreme climatic event disrupts patterns of locally adapted host-parasite combinations we measured the parasite's transmission success as well as the host's adaptive and innate immune defence under control and heat wave conditions. Independent of temperature, sympatric cercariae were always more successful than allopatric ones, indicating that parasites are locally adapted to their hosts. Hosts suffered from heat stress as suggested by fewer cells of the adaptive immune system (lymphocytes compared to the same groups that were kept at 18°C. However, the proportion of the innate immune cells (monocytes was higher in the 18°C water. Contrary to our expectations, no interaction between host immune defence, parasite infectivity and temperature stress were found, nor did the pattern of local adaptation change due to increased water temperature. Thus, in this host-parasite interaction, the sympatric parasite keeps ahead of the coevolutionary dynamics across sites, even under increasing temperatures as expected under marine global warming.

  6. Anthelmintic resistance in cattle nematodes in the US.

    Science.gov (United States)

    Gasbarre, Louis C

    2014-07-30

    The first documented case of macrocyclic lactone resistance in gastrointestinal (GI) nematodes of cattle was seen in the US approximately 10 years ago. Since that time the increase incidence of anthelmintic resistance has continued at an alarming rate. Currently parasites of the genera Cooperia and/or Haemonchus resistant to generic or brand-name macrocyclic lactones have be demonstrated in more than half of all operations examined. Both of these parasite genera are capable of causing economic losses by decreasing food intake and subsequently animal productivity. Currently, there are no easy and quick means to detect anthelmintic resistant GI nematodes. Definitive identification requires killing of cattle. The most commonly used field detection method is the fecal egg count reduction test (FECRT). This method can be adapted for use as a screening agent for Veterinarians and producers to identify less than desired clearance of the parasites after anthelmintic treatment. Further studies can then define the reasons for persistence of the egg counts. The appearance of anthelmintic resistance is largely due to the development of very effective nematode control programs that have significantly improved the productivity of the US cattle industry, but at the same time has placed a high level of selective pressure on the parasite genome. The challenges ahead include the development of programs that control the anthelmintic resistant nematodes but at the same time result in more sustainable parasite control. The goal is to maintain high levels of productivity but to exert less selective pressures on the parasites. One of the most effective means to slow the development of drug resistance is through the simultaneous use of multiple classes of anthelmintics, each of which has a different mode of action. Reduction of the selective pressure on the parasites can be attained through a more targeted approach to drug treatments where the producer's needs are met by selective

  7. Arrested larval development in cattle nematodes.

    Science.gov (United States)

    Armour, J; Duncan, M

    1987-06-01

    Most economically important cattle nematodes are able to arrest their larval development within the host - entering a period of dormancy or hypobiosis. Arrested larvae have a low death rate, and large numbers can accumulate in infected cattle during the grazing season. Because of this, outbreaks of disease caused by such nematodes can occur at times when recent infection with the parasites could not have occurred, for example during winter in temperature northern climates when cattle are normally housed. The capacity to arrest is a heritable trait. It is seen as an adaptation by the parasite to avoid further development to its free-living stages during times when the climate is unsuitable for free-living survival. But levels of arrestment can vary markedly in different regions, in different cattle, and under different management regimes. Climatic factors, previous conditioning, host immune status, and farm management all seem to affect arrestment levels. In this article, James Armour and Mary Duncan review the biological basis of the phenomenon, and discuss the apparently conflicting views on how it is controlled.

  8. ¹H, ¹³C and ¹⁵N chemical shift assignments of Na-FAR-1, a helix-rich fatty acid and retinol binding protein of the parasitic nematode Necator americanus.

    Science.gov (United States)

    Rey-Burusco, M Florencia; Ibañez-Shimabukuro, Marina; Cooper, Alan; Kennedy, Malcolm W; Córsico, Betina; Smith, Brian O

    2014-04-01

    The fatty acid and retinol-binding (FAR) proteins are a family of unusual helix-rich lipid binding proteins found exclusively in nematodes, and are secreted by a range of parasites of humans, animals and plants. Na-FAR-1 is from the parasitic nematode Necator americanus, an intestinal blood-feeding parasite of humans. Sequence-specific (1)H, (13)C and (15)N resonance assignments have been obtained for the recombinant 170 amino acid protein, using three-dimensional triple-resonance heteronuclear magnetic resonance experiments. Backbone assignments have been obtained for 99.3% of the non-proline HN/N pairs (146 out of 147). The amide resonance of T45 was not observed, probably due to rapid exchange with solvent water. A total of 96.9% of backbone resonances were identified, while 97.7% assignment of amino acid sidechain protons is complete. All Hα(166), Hβ(250) and Hγ(160) and 98.4% of the Hδ (126 out of 128) atoms were assigned. In addition, 99.4% Cα (154 out of 155) and 99.3% Cβ (143 out of 144) resonances have been assigned. No resonances were observed for the NH(n) groups of R93 NεHε, arginine, N(η1)H2, N(η2)H2, histidine N(δ1)H(δ1), N(ε1)H(ε1) and lysine N(ζ3)H3. Na-FAR-1 has a similar overall arrangement of α-helices to Ce-FAR-7 of the free-living Caeorhabditis elegans, but with an extra C-terminal helix.

  9. Evaluation of fallow and cover crops for nematode suppression in ...

    African Journals Online (AJOL)

    A study was conducted in three agroecological zones of south-western Nigeria to evaluate the effect of siam weed (Chromolaena odorata) and mucuna (Mucuna utilis) cover/fallow crops on plant-parasitic nematode population. The natural bush regrowth was used as control. Plant-parasitic nematodes were identified and ...

  10. A Survey of Nematode Infection in Oreochromis niloticus (L ...

    African Journals Online (AJOL)

    The incidence and intensity of nematode infection was investigated in Nile tilapia Oreochromis niloticus from Lake Kyoga, Uganda and 11% of the 406 fish examined were parasitized by nematodes of the genus Contracaecum. The prevalence of these parasites was greatest in the smallest and largest size classes, but this ...

  11. Mining the secretome of root-knot nematodes for cell wall modifying proteins

    NARCIS (Netherlands)

    Roze, E.H.A.

    2008-01-01

    The products of parasitism genes in nematodes must be secreted to reach their targets at the nematode-plant interface. These nematode secretory proteins are therefore recognised to play an important role in the nematode-plant interaction and as a result have been subject of intense study for years.

  12. Parasitylenchus sp. (Tylenchomorpha: Allantonematidae) parasitizing field populations of Harmonia axyridis (Coleoptera: Coccinellidae)

    DEFF Research Database (Denmark)

    Harding, Susanne; Poinar, George O. Jr.; Dimitrova, Desislava V.

    2011-01-01

    Adults of the invasive harlequin ladybird, Harmonia axyridis (Coleoptera: Coccinellidae), were found to be parasitized by nematodes (Tylenchomorpha: Allantonematidae) in Denmark. The nematodes were identified as Parasitylenchus sp. Major morphological characters of the nematodes did not differ...

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

    Science.gov (United States)

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

    2012-01-01

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

  14. Immunity comes first: the effect of parasite genotypes on adaptive immunity and immunization in three-spined sticklebacks.

    Science.gov (United States)

    Haase, David; Rieger, Jennifer K; Witten, Anika; Stoll, Monika; Bornberg-Bauer, Erich; Kalbe, Martin; Reusch, Thorsten B H

    2016-01-01

    Adaptive immunity in vertebrates can confer increased resistance against invading pathogens upon re-infection. But how specific parasite genotypes affect the temporal transition from innate to adaptive immunity under continual exposure to parasites is poorly understood. Here, we investigated the effects of homologous and heterologous exposures of genetically distinct parasite lineages of the eye fluke Diplostomum pseudospathaceum on gene expression patterns of adaptive immunity in sticklebacks (Gasterosteus aculeatus). Observable differences in gene expression were largely attributable to final exposures while there was no transcription pattern characteristic for a general response to repeated infections with D. pseudospathaceum. None of the final exposure treatments was able to erase the distinct expression patterns resulting from a heterologous pre-exposed fish. Interestingly, heterologous final exposures showed similarities between different treatment groups subjected to homologous pre-exposure. The observed pattern was supported by parasite infection rates and suggests that host immunization was optimized towards an adaptive immune response that favored effectiveness against parasite diversity over specificity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Long-term effects of eight soil health treatments to control plant-parasitic nematodes and Verticillium dahliae in agro-ecosystems

    NARCIS (Netherlands)

    Korthals, G.W.; Thoden, T.C.; Berg, van den W.; Visser, J.H.M.

    2014-01-01

    There is an urgent need to test and develop sustainable methods for management of soil pathogens, such as the root-lesion nematode Pratylenchus penetrans and the soil fungus Verticillium dahliae. Ultimately this should be investigated with a multidisciplinary approach, with long-term measurements of

  16. Genetic variation of fish parasite populations in historically connected habitats: undetected habitat fragmentation effect on populations of the nematode Procamallanus fulvidraconis in the catfish Pelteobagrus fulvidraco.

    Science.gov (United States)

    Li, Wen X; Wang, Gui T; Nie, P

    2008-06-01

    Habitat fragmentation may have some significant effects on population genetic structure because geographic distance and physical barriers may impede gene flow between populations. In this study, we investigated whether recent habitat fragmentation affected genetic structure and diversity of populations of the nematode Procamallanus fulvidraconis in the yellowhead catfish, Pelteobagrus fulvidraco. The nematode was collected from 12 localities in 7 floodplain lakes of the Yangtze River. Using 11 intersimple sequence repeat markers, analysis of molecular variance showed that genetic diversity occurred mainly within populations (70.26%). Expected heterozygosity (He) of P. fulvidraconis was barely different between connected (0.2105) and unconnected lakes (0.2083). Population subdivision (Fst) between connected lakes (0.2177) was higher than in unconnected lakes (0.1676). However, the connected and unconnected lakes did not cluster into 2 clades. A Mantel test revealed significant positive correlation between genetic and geographic distances (R = 0.5335, P < 0.01). These results suggest that habitat fragmentation did not cause genetic differentiation among populations or a reduction of diversity in isolated populations of P. fulvidraconis. At least 2 factors may increase the dispersal range of the nematode, i.e., flash flooding in summer and other species of fish that may serve as the definitive hosts. Moreover, lake fragmentation is probably a recent process; population size of the nematode in these lakes is large enough to maintain population structure.

  17. Screening of the ‘Open Scaffolds’ collection from Compounds Australia identifies a new chemical entity with anthelmintic activities against different developmental stages of the barber's pole worm and other parasitic nematodes

    Directory of Open Access Journals (Sweden)

    Sarah Preston

    2017-12-01

    Full Text Available The discovery and development of novel anthelmintic classes is essential to sustain the control of socioeconomically important parasitic worms of humans and animals. With the aim of offering novel, lead-like scaffolds for drug discovery, Compounds Australia released the ‘Open Scaffolds’ collection containing 33,999 compounds, with extensive information available on the physicochemical properties of these chemicals. In the present study, we screened 14,464 prioritised compounds from the ‘Open Scaffolds’ collection against the exsheathed third-stage larvae (xL3s of Haemonchus contortus using recently developed whole-organism screening assays. We identified a hit compound, called SN00797439, which was shown to reproducibly reduce xL3 motility by ≥ 70%; this compound induced a characteristic, “coiled” xL3 phenotype (IC50 = 3.46–5.93 μM, inhibited motility of fourth-stage larvae (L4s; IC50 = 0.31–12.5 μM and caused considerable cuticular damage to L4s in vitro. When tested on other parasitic nematodes in vitro, SN00797439 was shown to inhibit (IC50 = 3–50 μM adults of Ancylostoma ceylanicum (hookworm and first-stage larvae of Trichuris muris (whipworm and eventually kill (>90% these stages. Furthermore, this compound completely inhibited the motility of female and male adults of Brugia malayi (50–100 μM as well as microfilariae of both B. malayi and Dirofilaria immitis (heartworm. Overall, these results show that SN00797439 acts against genetically (evolutionarily distant parasitic nematodes i.e. H. contortus and A. ceylanicum [strongyloids] vs. B. malayi and D. immitis [filarioids] vs. T. muris [enoplid], and, thus, might offer a novel, lead-like scaffold for the development of a relatively broad-spectrum anthelmintic. Our future work will focus on assessing the activity of SN00797439 against other pathogens that cause neglected

  18. Nematode Interactions in Nature: Models for Sustainable Control of Nematode Pests of Crop Plants?

    NARCIS (Netherlands)

    Putten, van der W.H.; Cook, R.; Costa, S.; Davies, K.G.; Fargette, M.; Freitas, H.; Hol, W.H.G.; Kerry, B.R.; Maher, N.; Mateille, T.; Moens, M.; Peña, de la E.; Piskiewicz, A.M.; Raeymaekers, A.D.W.; Rodriquez-Echeverria, S.; Wurff, van der A.W.G.

    2006-01-01

    Plant-parasitic nematodes are major crop pests in agro-ecosystems while in nature their impact may range from substantial to no significant growth reduction. The aim of this review is to determine if nematode population control in natural ecosystems may provide us with a model for enhancing

  19. Nematode interactions in nature: models for sustainable control of nematode pests of crop plants?

    NARCIS (Netherlands)

    Van der Putten, W.H.; Cook, R.; Costa, S.R.; Davies, K.G.; Fargette, M.; Freitas, H.; Hol, W.H.G.; Kerry, B.R.; Maher, N.; Mateille, T.; Moens, M.; De la Peña, E.; Piskiewicz, A.; Raeymaekers, A.; Rodríguez-Echeverría, S.; Van der Wurff, A.W.G.

    2006-01-01

    Plant-parasitic nematodes are major crop pests in agro-ecosystems while in nature their impact may range from substantial to no significant growth reduction. The aim of this review is to determine if nematode population control in natural ecosystems may provide us with a model for enhancing

  20. Ecological consequences of manipulative parasites: chapter 9

    Science.gov (United States)

    Lafferty, Kevin D.; Kuris, A. M.

    2012-01-01

    Parasitic "puppet masters", with their twisted, self-serving life history strategies and impressive evolutionary takeovers of host minds, capture the imagination of listeners—even those that might not normally fi nd the topic of parasitism appealing (which includes most everyone). A favorite anecdote concerns the trematode Leucochloridium paradoxum migrating to the eyestalks of its intermediate host snail and pulsating its colored body, presumably to attract the predatory birds that are the final hosts for the worm. Identifying a parasite as “manipulative” infers that a change in host behavior or appearance is a direct consequence of the parasite’s adaptive actions that, on average, will increase the fi tness of the parasite. The list of parasites that manipulate their hosts is long and growing. Holmes and Bethel (1972) presented the earliest comprehensive review and brought the subject to mainstream ecologists. Over two decades ago, Andy Dobson (1988) listed seven cestodes, seven trematodes, ten acanthocephalans, and three nematodes that manipulated host behavior. Fifteen years later, Janice Moore (2002) filled a book with examples. The five infectious trophic strategies, typical parasites (macroparasites), pathogens, trophically transmitted parasites, parasitic castrators, and parasitoids (Kuris and Lafferty 2000; Lafferty and Kuris 2002, 2009) can modify host behavior, but the likelihood that a parasite manipulates behavior differs among strategies. The most studied infectious agents, non-trophically transmitted pathogens and macroparasites, have enormous public health, veterinary, and wildlife disease importance, yet few manipulate host behavior. The beststudied manipulative infectious agents are trophically transmitted parasites in their prey intermediate hosts. Parasitoids and parasitic castrators can also manipulate host behavior, but for different purposes and with different implications. Several studies of manipulative parasites conclude with

  1. (Cobb) Thorne, parasite de

    African Journals Online (AJOL)

    Lazare

    2012-10-11

    Oct 11, 2012 ... Plant parasitic nematodes are microscopic worms, measuring less than. 1 mm in length (Quénéhervé, 2008). They are obligate parasites that feed mostly on plant roots causing symptoms such as necrosis, lesions and galls on the roots (Sarah et al., 1996; Bridge et al., 1997; De Waele and Romulo, 1998).

  2. The nuclear receptor DAF-12 regulates nutrient metabolism and reproductive growth in nematodes.

    Directory of Open Access Journals (Sweden)

    Zhu Wang

    2015-03-01

    Full Text Available Appropriate nutrient response is essential for growth and reproduction. Under favorable nutrient conditions, the C. elegans nuclear receptor DAF-12 is activated by dafachronic acids, hormones that commit larvae to reproductive growth. Here, we report that in addition to its well-studied role in controlling developmental gene expression, the DAF-12 endocrine system governs expression of a gene network that stimulates the aerobic catabolism of fatty acids. Thus, activation of the DAF-12 transcriptome coordinately mobilizes energy stores to permit reproductive growth. DAF-12 regulation of this metabolic gene network is conserved in the human parasite, Strongyloides stercoralis, and inhibition of specific steps in this network blocks reproductive growth in both of the nematodes. Our study provides a molecular understanding for metabolic adaptation of nematodes to their environment, and suggests a new therapeutic strategy for treating parasitic diseases.

  3. Activity of components of the antioxidant system in the roots of potato plants at short-term temperature drop and invasion with parasitic nematodes.

    Science.gov (United States)

    Lavrova, V V; Matveeva, E M; Zinovieva, S V

    2017-09-01

    The activity of catalase and superoxide dismutase in the roots of susceptible plants and plants exposed to alternating temperatures, which were infected with the phytoparasitic nematode G. rostochiensis, was studied. It was found that, throughout the invasion period, the plants susceptible to invasion exhibited a high activity of these enzymes, which allowed them to maintain an active defense against the oxidative stress caused by the invasion and subsequent life activity of larvae. For the plants exposed to alternating temperatures, a decrease in the activity of catalase and superoxide dismutase at the early stages of invasion and an increase in the activity of these enzymes at the later stages was detected.

  4. Adaptive responses and latent costs of multigeneration cadmium exposure in parasite resistant and susceptible strains of a freshwater snail

    Energy Technology Data Exchange (ETDEWEB)

    Salice, Christopher J.; Anderson, Todd; Roesijadi, Guritno

    2010-11-01

    Population response to anthropogenic activities will be influenced by prior adaptation to environmental conditions. We tested how parasite-resistant and -susceptible strains of a freshwater snail responded to cadmium and elevated temperature challenges after having been exposed to low-level cadmium continuously for multiple generations. Snails exposed to cadmium for three generations were removed for the fourth generation, and challenged in the fifth generation with (1) chronic cadmium exposure over the entire life cycle, (2) acute cadmium exposure of adults, and (3) elevated temperature challenge of adults. The parasite susceptible NMRI strain is more cadmium tolerant than the parasite resistant BS90 strain and remained more tolerant than BS90 throughout this study. Additionally, NMRI exhibited greater adaptive capacity for cadmium than BS90 and became more tolerant of both chronic and acute cadmium challenges, while BS90 became more tolerant of acute cadmium challenge only. Fitness costs, reflected in population growth rate, were not apparent in fifth generation snails maintained in cadmium-free conditions. However, costs were latent and expressed as decreased tolerance to a secondarily imposed temperature stress. Adaptation to prior selection pressures can influence subsequent adaptation to anthropogenic stresses and may have associated costs that reduce fitness in novel environments.

  5. Deep-sea parasitic nematodes of the genus Trophomera Rubtsov et Platonova, 1974 (Benthimermithidae) from the Equatorial Atlantic, with the descriptions of two new species

    Science.gov (United States)

    Miljutin, Dmitry M.

    2011-06-01

    Nematode females of the genus Trophomera (Benthimermithidae) from the collection of the Smithsonian's National Museum of Natural History (Washington, DC, USA) were examined. Nematodes were collected in different parts of the Western Atlantic (Hatteras Abyssal Plain, Brazil Basin, and Argentina Basin) from depths of 467-5,223 m. Two new species are described. Body length of T. americana sp. n. is 3,250-4,470 μm; posterior end conical with rounded tip; cephalic setae about 3-4 μm long; trophosome consisting of several longitudinal rows of large cells; ovaries reflected; mature eggs 35 μm in diameter. Body length of T. longiovaris sp. n. is 7,870-15,400 μm; posterior end conical with rounded tip; cephalic sensilla 7 μm long; mouth opening vestigial, present as very narrow apical pore; pharynx devoid of internal lumen and muscular envelope; midgut represents a trophosome without internal lumen; trophosomal cells arranged in 3-4 longitudinal rows; rectum and anus vestigial; female reproductive system didelphic, amphidelphic, very long, occupying about 0.8 total body length; ovaries telogonic, outstretched; oviducts very long, repeatedly folded across body axis; proximal parts of oviducts being than distal ones, uterus distinctly formed. New finds of two known species, T. arnauidi and T. marionensis, are also recorded and described.

  6. Phytopathogenic Nematodes

    NARCIS (Netherlands)

    Helder, J.; Vervoort, M.T.W.; Megen, van H.H.B.; Rybarczyk-Mydlowska, K.; Quist, C.W.; Smant, G.; Bakker, J.

    2015-01-01

    Soil is teeming with life, and rhizosphere soil is even more densely in habited than bulk soil. In terms of biomass, bacteria and fungi are dominant groups, whereas nematodes (roundworms) are the most abundant Metazoans. Bulk soil, soil not directly affected by living plant roots, typically harbours

  7. Growing Tomato ( Lycopersicon esculentum L.) in Nematode ...

    African Journals Online (AJOL)

    Parasitic root-knot nematodes are a threat to tomato production. In this study, the effect of Procarvian carpensis manure at a rate of 5tons/ha and the balanced NPK inorganic fertilizer at a rate of 100kg/ha on the growth performance of the tomato genotype “Duluti” on a highly root-knot nematode soil was evaluated. The field ...

  8. Capacity of the terrestrial entomopathogenic nematode Steinernema rarum (Rhabditida: Steinernematidae to parasite Culex apicinus larvae (Diptera: Culicidae Capacidad del nemátodo terrestre entomopatógeno Steinernema rarum (Rhabditida: Steinernematidae de parasitar larvas de Culex apicinus (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Susana R. Cagnolo

    2010-06-01

    Full Text Available Entomopathogenic nematodes can be considered effective agents for biocontrol, resulting innocuous for humans. Larvaeof Culex apicinus Philippi were exposed to infective juveniles of Steinernema rarum (OLI strain under laboratory conditions, testing six doses (1:1, 5:1, 10:1, 15:1, 100:1, 400:1. An increasing percentage of mosquito larvae mortality was recorded with an increased dose. The highest percentage of mosquito larvae mortality (75% was obtained with the dose 400:1. This is the first report of parasitism of an isolated of S. rarum from Córdoba against larvae of C. apicinus, with promising results. Therefore, further studies must be carried out to determine if these nematodes would be effective as autochthonous agents for the control of Culex Linnaeus and other mosquitoes of sanitary interest in the country.Los nemátodos entomopatógenos son considerados eficientes agentes de control de insectos plaga e inocuos para los humanos. Larvas de Culex apicinus Philippi fueron expuestas a seis dosis (1:1, 5:1, 10:1, 15:1, 100:1, 400:1 de juveniles infectivos de Steinernema rarum (aislado OLI. Se registró un incremento en la mortalidad de las larvas del mosquito con el aumento de la dosis del nematodo. El mayor porcentaje de mortalidad de larvas del mosquito (75% se obtuvo con la dosis 400:1. Este es el primer reporte de parasitismo de un aislado de S. rarum de Córdoba, en larvas de C. apicinus con resultados promisorios. Por lo tanto, se debería profundizar su estudio para determinar si pueden resultar efectivos como agentes autóctonos para el control biológico de mosquitos Culex Linnaeus, y otros de interés sanitario en el país.

  9. Two new species of nematode parasites, Cucullanus epinepheli sp n. (Cucullanidae) and Procamallanus (Spirocamallanus) sinespinis sp n. (Camallanidae), from marine serranid and haemulid fishes off New Caledonia

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Justine, J.-L.

    2017-01-01

    Roč. 64, 5 April (2017), č. článku 011. ISSN 1803-6465 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Nematoda * helminth parasite * Seuratoidea * Camallanoidea * Epinephelus * Pomadasys * South Pacific Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 1.082, year: 2016

  10. Characterization and Function of the Inflammatory Response to Infection by a Gastrointestinal Nematode Parasite: New Insights into Protective Th2 Responses

    Science.gov (United States)

    2006-01-01

    identifies macrophages as important effector cells in protective Th2 responses, providing a possible explanation for the evolution of their...expression of chitinases and chitinase-like genes suggests a potential effector mechanism, as some helminth parasites feature a chitin cuticle that...M.B. Ascaris lumbricoides aggregation in relation to child growth status, delayed cutaneous hypersensitivity, and plant anthelmintic use in

  11. A survey of nematodes of the genus Cucullanus Müller, 1777 (Nematoda, Seuratoidea) parasitic in marine fishes off Brazil, including description of three new species

    Czech Academy of Sciences Publication Activity Database

    Vieira, F.M.; Pereira, F.B.; Pantoja, C.; Soares, I.A.; Pereira, A.N.; Timi, J.T.; Scholz, Tomáš; Luque, J.L.

    2015-01-01

    Roč. 4039, č. 2 (2015), s. 289-311 ISSN 1175-5326 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : new species * Cucullanidae * parasites * Lophiiformes * Perciformes * Gadiformes * Anguilliformes * Ophidiiformes Subject RIV: EG - Zoology Impact factor: 0.994, year: 2015

  12. Fungi associated with free-living soil nematodes in Turkey

    Directory of Open Access Journals (Sweden)

    Karabörklü Salih

    2015-01-01

    Full Text Available Free-living soil nematodes have successfully adapted world-wide to nearly all soil types from the highest to the lowest of elevations. In the current study, nematodes were isolated from soil samples and fungi associated with these free-living soil nematodes were determined. Large subunit (LSU rDNAs of nematode-associated fungi were amplified and sequenced to construct phylogenetic trees. Nematode-associated fungi were observed in six nematode strains belonging to Acrobeloides, Steinernema and Cephalobus genera in different habitats. Malassezia and Cladosporium fungal strains indicated an association with Acrobeloides and Cephalobus nematodes, while Alternaria strains demonstrated an association with the Steinernema strain. Interactions between fungi and free-living nematodes in soil are discussed. We suggest that nematodes act as vectors for fungi.

  13. Comparative Heterochromatin Profiling Reveals Conserved and Unique Epigenome Signatures Linked to Adaptation and Development of Malaria Parasites.

    Science.gov (United States)

    Fraschka, Sabine A; Filarsky, Michael; Hoo, Regina; Niederwieser, Igor; Yam, Xue Yan; Brancucci, Nicolas M B; Mohring, Franziska; Mushunje, Annals T; Huang, Ximei; Christensen, Peter R; Nosten, Francois; Bozdech, Zbynek; Russell, Bruce; Moon, Robert W; Marti, Matthias; Preiser, Peter R; Bártfai, Richárd; Voss, Till S

    2018-03-14

    Heterochromatin-dependent gene silencing is central to the adaptation and survival of Plasmodium falciparum malaria parasites, allowing clonally variant gene expression during blood infection in humans. By assessing genome-wide heterochromatin protein 1 (HP1) occupancy, we present a comprehensive analysis of heterochromatin landscapes across different Plasmodium species, strains, and life cycle stages. Common targets of epigenetic silencing include fast-evolving multi-gene families encoding surface antigens and a small set of conserved HP1-associated genes with regulatory potential. Many P. falciparum heterochromatic genes are marked in a strain-specific manner, increasing the parasite's adaptive capacity. Whereas heterochromatin is strictly maintained during mitotic proliferation of asexual blood stage parasites, substantial heterochromatin reorganization occurs in differentiating gametocytes and appears crucial for the activation of key gametocyte-specific genes and adaptation of erythrocyte remodeling machinery. Collectively, these findings provide a catalog of heterochromatic genes and reveal conserved and specialized features of epigenetic control across the genus Plasmodium. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Social Parasites

    Science.gov (United States)

    Lopez, Miguel A.; Nguyen, HoangKim T.; Oberholzer, Michael; Hill, Kent L.

    2011-01-01

    Summary of recent advances Protozoan parasites cause tremendous human suffering worldwide, but strategies for therapeutic intervention are limited. Recent studies illustrate that the paradigm of microbes as social organisms can be brought to bear on questions about parasite biology, transmission and pathogenesis. This review discusses recent work demonstrating adaptation of social behaviors by parasitic protozoa that cause African sleeping sickness and malaria. The recognition of social behavior and cell-cell communication as a ubiquitous property of bacteria has transformed our view of microbiology, but protozoan parasites have not generally been considered in this context. Works discussed illustrate the potential for concepts of sociomicrobiology to provide insight into parasite biology and should stimulate new approaches for thinking about parasites and parasite-host interactions. PMID:22020108

  15. Efeito do pastejo rotacionado e alternado com bovinos adultos no controle da verminose em ovelhas Effect of rotational and alternate grazing with adult cattle on the control of nematode parasites in sheep

    Directory of Open Access Journals (Sweden)

    L.H. Fernandes

    2004-12-01

    Full Text Available Estudaram-se os efeitos do pastejo alternado de ovinos e bovinos e do pastejo rotacionado sobre o controle da verminose em ovelhas. Utilizou-se uma área experimental composta por três módulos de 1,67ha cada. Os módulos foram subdivididos em oito piquetes. Vinte ovelhas foram colocadas no módulo 1 e quatro bovinos adultos no módulo 2. Os animais permaneceram em cada piquete do módulo por cinco dias, totalizando 40 dias de permanência em cada módulo. Ao final desse período, as ovelhas foram transferidas para o módulo onde estavam os bovinos e estes para o módulo onde estavam os ovinos, mantendo esse esquema até o final do experimento. Um grupo-controle de 20 ovelhas foi mantido, também em sistema rotacionado, em um terceiro módulo, sem compartilhar a pastagem. As ovelhas submetidas ao manejo com bovinos apresentaram o menor grau de infecção por nematódeos gastrintestinais e os maiores valores de volume globular. O pastejo rotacionado de ovinos, sem a utilização de bovinos, não foi eficiente no controle da verminose das ovelhas. A utilização do pastejo rotacionado e alternado de ovinos e bovinos adultos exerceu efeito benéfico significativo no controle da verminose ovina.The effects of rotational and alternate grazing involving cattle and sheep on the control of nematode parasites in sheep were evaluated. Three areas with 1.67ha were subdivided into eight paddocks each. Twenty ewes and four cattle were allotted to areas 1 and 2, respectively. They grazed during five days in each of eight paddocks of each area. The sheep and cattle rotated in each area for 40 days. At the end of this period, ewes were transferred to the area where cattle were previously kept and these animals were transferred to the area where sheep had previously grazed. This arrangement was kept until the end of the experiment. A control group with 20 ewes rotated in the third area, also with eight paddocks. Ewes that alternately grazed with cattle showed

  16. Cattle and Nematodes Under Global Change: Transmission Models as an Ally.

    Science.gov (United States)

    Verschave, Sien H; Charlier, Johannes; Rose, Hannah; Claerebout, Edwin; Morgan, Eric R

    2016-09-01

    Nematode infections are an important economic constraint to cattle farming. Future risk levels and transmission dynamics will be affected by changes in climate and farm management. The prospect of altered parasite epidemiology in combination with anthelmintic resistance requires the adaptation of current control approaches. Mathematical models that simulate disease dynamics under changing climate and farm management can help to guide the optimization of helminth control strategies. Recent efforts have increasingly employed such models to assess the impact of predicted climate scenarios on future infection pressure for gastrointestinal nematodes (GINs) in cattle, and to evaluate possible adaptive control measures. This review aims to consolidate progress in this field to facilitate further modeling and application. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. An extensive comparison of the effect of anthelmintic classes on diverse nematodes

    Science.gov (United States)

    Soil-transmitted helminths are parasitic nematodes that inhabit the human intestine. These parasites, which include two hookworm species, Ancylostoma duodenale and Necator americanus, the whipworm Trichuris trichiura, and the large roundworm Ascaris lumbricoides, infect upwards of two billion people...

  18. Book review: Systematics of Cyst Nematodes (Nematoda: Heteroderinae)

    Science.gov (United States)

    The cyst nematodes are an important group of plant-parasitic nematodes that cause billions of dollars in economic damage to crops every year. This article reviews a recently published, two-volume monograph that describes the morphological and molecular characteristics of these agriculturally signif...

  19. Prevalence of trichostrongylid nematode in sheeps in Benin City ...

    African Journals Online (AJOL)

    Parasitism of Trichostrongylid nematode is a world-wide problem for both small and large scale farmers and is a great threat to the livestock industry and also a major constraint to the wellbeing and productive performance of ruminant animals. This study was carried out to determine the effect of Trichostrongylid nematode in ...

  20. Plants producing pyrrolizidine alkaloids: sustainable tools for nematode management?

    NARCIS (Netherlands)

    Thoden, T.C.; Boppre, M.

    2010-01-01

    1,2-dehydropyrrolizidine ester alkaloids (pyrrolizidine alkaloids; PAs) are a class of secondary plant metabolites found in hundreds of plant species. In vitro, PAs are known to affect plant-parasitic nematodes. Thus, PA-producing plants might be used in nematode management. So far, however,

  1. Excretory/secretory products from the gastrointestinal nematode Trichuris muris.

    Science.gov (United States)

    Tritten, Lucienne; Tam, Mifong; Vargas, Mireille; Jardim, Armando; Stevenson, Mary M; Keiser, Jennifer; Geary, Timothy G

    2017-07-01

    To better control gastrointestinal nematode infections in humans and animals, it is important to understand the strategies used by these parasites to modulate the host immune system. In this regard, molecules released by parasites have been attributed crucially important roles in host-parasite negotiations. We characterized the excretory/secretory (E/S) microRNA (miRNA) and protein profiles from the mouse gastrointestinal nematode parasite Trichuris muris. Released miRNAs were subjected to miRNA sequencing and E/S proteins were analysed by mass spectrometry. Fourteen miRNAs were identified in T. muris exosome-like vesicles, as well as 73 proteins of nematode origin, 11 of which were unique to this study. Comparison with published nematode protein secretomes revealed high conservation at the functional level. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Studies on the parasites of zebras. V. Nematodes of the Burchell's and Hartmann's mountain zebras from the Etosha National Park, South West Africa/Namibia.

    Science.gov (United States)

    Krecek, R C; Reinecke, R K; Malan, F S

    1987-03-01

    Nine Burchell's and 6 Hartman's mountain zebras were culled during the 3 climatic periods characteristic of the Etosha National Park, South West Africa/Namibia, and were examined for helminths. The Burchell's zebras ranged in age from 4 1/2 to 19 years and the mountain zebras from 3 1/2 to 13 years. Twenty-five species of nematodes, belonging to the families Atractidae, Strongylidae, Oxyuridae, Onchocercidae and Habronematidae, were recovered. Of the family Cyathostominae, the following species were the most numerous in the Burchell's zebras: Cyathostomum montgomeryi (7 120-67 042), Cylicocyclus triramosus (11-34 540), Cylicostephanus minutus (4 698-40 019) and Cylindropharynx sp. (? intermedia) (3 591-40 018). The atractids present were: Crossocephalus viviparus (20-5 045 212) and Probstmayria vivipara (5 140-3 801 300). Three of the above cyathostome species were also most abundant in mountain zebras: Cylicocyclus triramosus (54-19 782), Cylicostephanus minutus (555-12 396) and Cylindrophrynx sp. (? intermedia) (3-5 325). New reports include Cylicostephanus longiconus in the Burchell's zebras and Cyathostomum alveatum, Cyathostomum montgomeryi, Cylicostephanus bidentatus and Draschia megastoma in the mountain zebra. The overwintering of 4th stage cyathostomes in the gut walls and their emergence which differ in the 2 hosts, are discussed.

  3. Um nematodeo parasito do pinguim Spheniscus magellanicus (Forster (Ascaridoidea, Anisakidae A nematode parasite of the penguin Spheniscus magellanicus (Forster (Ascaroidea, Anisakidae

    Directory of Open Access Journals (Sweden)

    Cláudia Portes Santos

    1984-06-01

    Full Text Available O material estudado foi coletado no "pinguim naufragado", Sphenicus magellanicus (Forster, na baia de Guanabara, Rio de Janeiro e cedido pela bióloga Carla Chediak. Foram examinadas onze fêmeas e três machos, sendo depositados na coleção do Instituto Oswaldo Cruz (IOC sob o numero 31.639. Foi ainda examinado o material pertencente a coleção do IOC, ainda não identificado, tambem coletado do mesmo hospedeiro no Rio de Janeiro, de numeros 20.986 e 30.257.The nematodes were collected from the penguin Spheniscus magellanicus (Forster (Sphenisciformes. A study from the main species of Contracaecum that occur in penguins and piscivorous birds from the south hemisphere is made, more specifically the C. eudyptulae Johnston & Mawson, 1942a, C. eudyptes Johnston & Mawson, 1953, C. heardi Mawson, 1953, C. antarcticum Johnston, 1938, C. prevosli Tchéprakoff, 1966, C. spiculigerum (Rudolphi, 1809, C. osculatum (Rudolphi, 1802, C. scotti (Leiper & Atkinson, 1914 and C. pelagicum Johnston & Mawson, 1942b. C. pelagicum is redescribed and turns to be a new rference for Spheniscus magellanicus (Foster.

  4. Helminths of Wild Predatory Mammals of Ukraine. Nematodes

    Directory of Open Access Journals (Sweden)

    Varodi E. I.

    2017-06-01

    Full Text Available The article summarizes information on the nematodes parasitic in wild Carnivora of Ukraine. Totally, 50 species of nematodes are known to parasitise carnivorans in the country, 30 species were registered in the present study. Nematodes were found in 14 species of examined hosts from the families Canidae, Mustelidae and Felidae. Maximum diversity of nematodes of carnivorans was observed in Polissia (forest zone in the north of the country and in Kherson Region in the south. Hosts from the family Canidae harboured 19 nematode species; studied species of the Mustelidae were infected with 15 nematode species, 6 of them were also found in Canidae. The wildcat (Felis silvestris Schreber and the lynx (Lynx lynx Linnaeus harboured only two species of nematodes, both are specific parasites of these hosts. The most comprehensive information concerns the nematode communities of the red fox (Vulpes vulpes Linnaeus and the wolf (Canis lupus Linnaeus, with 19 and 9 nematode species found, correspondingly. From 1 to 6 nematode species were found in other species of carnivorans.

  5. Generalists at the interface: Nematode transmission between wild and domestic ungulates

    Directory of Open Access Journals (Sweden)

    Josephine G. Walker

    2014-12-01

    Full Text Available Many parasitic nematode species are generalists capable of infecting multiple host species. The complex life cycle of nematodes, involving partial development outside of the host, facilitates transmission of these parasites between host species even when there is no direct contact between hosts. Infective nematode larvae persist in the environment, and where grazing or water sources are shared ingestion of parasite larvae deposited by different host species is likely. In this paper we examine the extent to which nematode parasite species have been observed in sympatric wild and domestic ungulates. First, using existing host–parasite databases, we describe expected overlap of 412 nematode species between 76 wild and 8 domestic ungulate host species. Our results indicate that host-specific parasites make up less than half of the nematode parasites infecting any particular ungulate host species. For wild host species, between 14% (for common warthog and 76% (for mouflon of parasitic nematode species are shared with domestic species. For domestic host species, between 42% (for horse and 77% (for llamas/alpacas of parasitic nematode species are shared with wild species. We also present an index of liability to describe the risk of cross-boundary parasites to each host species. We then examine specific examples from the literature in which transmission of nematode parasites between domestic and wild ungulates is described. However, there are many limitations in the existing data due to geographical bias and certain host species being studied more frequently than others. Although we demonstrate that many species of parasitic nematode are found in both wild and domestic hosts, little work has been done to demonstrate whether transmission is occurring between species or whether similar strains circulate separately. Additional research on cross-species transmission, including the use of models and of genetic methods to define strains, will provide

  6. Generalists at the interface: Nematode transmission between wild and domestic ungulates.

    Science.gov (United States)

    Walker, Josephine G; Morgan, Eric R

    2014-12-01

    Many parasitic nematode species are generalists capable of infecting multiple host species. The complex life cycle of nematodes, involving partial development outside of the host, facilitates transmission of these parasites between host species even when there is no direct contact between hosts. Infective nematode larvae persist in the environment, and where grazing or water sources are shared ingestion of parasite larvae deposited by different host species is likely. In this paper we examine the extent to which nematode parasite species have been observed in sympatric wild and domestic ungulates. First, using existing host-parasite databases, we describe expected overlap of 412 nematode species between 76 wild and 8 domestic ungulate host species. Our results indicate that host-specific parasites make up less than half of the nematode parasites infecting any particular ungulate host species. For wild host species, between 14% (for common warthog) and 76% (for mouflon) of parasitic nematode species are shared with domestic species. For domestic host species, between 42% (for horse) and 77% (for llamas/alpacas) of parasitic nematode species are shared with wild species. We also present an index of liability to describe the risk of cross-boundary parasites to each host species. We then examine specific examples from the literature in which transmission of nematode parasites between domestic and wild ungulates is described. However, there are many limitations in the existing data due to geographical bias and certain host species being studied more frequently than others. Although we demonstrate that many species of parasitic nematode are found in both wild and domestic hosts, little work has been done to demonstrate whether transmission is occurring between species or whether similar strains circulate separately. Additional research on cross-species transmission, including the use of models and of genetic methods to define strains, will provide evidence to answer this

  7. Nest sanitation behavior in hirundines as a pre-adaptation to egg rejection to counter brood parasitism.

    Science.gov (United States)

    Yang, Canchao; Wang, Longwu; Liang, Wei; Møller, Anders Pape

    2015-01-01

    Previous studies suggested that nest sanitation behavior may have been a pre-adaptation from which egg rejection of brood parasite eggs evolved. We tested this hypothesis in two swallow species, the red-rumped swallow (Cecropis daurica) and the barn swallow (Hirundo rustica). Our results indicated that the red-rumped swallow, which is an accepter of foreign eggs, rejected a low percentage of non-egg-shaped objects and did so less often than the barn swallow, which is an intermediate rejecter of foreign eggs. Furthermore, the egg rejection rates of the barn swallow increased with the increase in rejection rates of non-egg-shaped objects among different populations. These results showed that nest cleaning behavior could have evolved into a means of reducing the costs of brood parasitism, suggesting that egg recognition ability has evolved from recognition of non-egg-shaped objects. This finding advances our understanding of the evolution of egg recognition behavior in birds.

  8. A Long Temporal Study of Parasitism in Asexual-Sexual Populations of Carassius gibelio: Does the Parasite Infection Support Coevolutionary Red Queen Dynamics?

    Directory of Open Access Journals (Sweden)

    Tomáš Pakosta

    2018-01-01

    Full Text Available Carassius gibelio is an extraordinary cyprinid species exhibiting both sexual and asexual reproduction. We hypothesized that parasitism selection is one of the potential mechanisms contributing to the coexistence of the two reproductive forms of C. gibelio living in the same habitat. We performed a four-year study to investigate the dynamics of parasite infection in C. gibelio. According to the Red Queen prediction, the asexual form is a target of parasite adaptation due to its low genetic variability. Both sexual and gynogenetic forms of C. gibelio exhibited similar levels of prevalence, with monogeneans being the most frequently observed parasite group. We observed the temporal dynamics of parasite infection in the last year of investigation, when both forms were more strongly parasitized. The sexual form was more parasitized by ectoparasites in the first and last years and less parasitized by nematodes in the last year when compared to the gynogenetic form. We found no trend of high parasite infection in gynogenetic mtDNA haplotypes. We conclude that Red Queen dynamics is not the mechanism driving parasite infection in sexual-gynogenetic C. gibelio over a long time scale. Alternatively, we suggest that the dynamics of parasite infection in this complex may be generated by multiple mechanisms.

  9. Antitumor effect of malaria parasite infection in a murine Lewis lung cancer model through induction of innate and adaptive immunity.

    Directory of Open Access Journals (Sweden)

    Lili Chen

    Full Text Available BACKGROUND: Lung cancer is the most common malignancy in humans and its high fatality means that no effective treatment is available. Developing new therapeutic strategies for lung cancer is urgently needed. Malaria has been reported to stimulate host immune responses, which are believed to be efficacious for combating some clinical cancers. This study is aimed to provide evidence that malaria parasite infection is therapeutic for lung cancer. METHODOLOGY/PRINCIPAL FINDINGS: Antitumor effect of malaria infection was examined in both subcutaneously and intravenously implanted murine Lewis lung cancer (LLC model. The results showed that malaria infection inhibited LLC growth and metastasis and prolonged the survival of tumor-bearing mice. Histological analysis of tumors from mice infected with malaria revealed that angiogenesis was inhibited, which correlated with increased terminal deoxynucleotidyl transferase-mediated (TUNEL staining and decreased Ki-67 expression in tumors. Through natural killer (NK cell cytotoxicity activity, cytokine assays, enzyme-linked immunospot assay, lymphocyte proliferation, and flow cytometry, we demonstrated that malaria infection provided anti-tumor effects by inducing both a potent anti-tumor innate immune response, including the secretion of IFN-γ and TNF-α and the activation of NK cells as well as adaptive anti-tumor immunity with increasing tumor-specific T-cell proliferation and cytolytic activity of CD8(+ T cells. Notably, tumor-bearing mice infected with the parasite developed long-lasting and effective tumor-specific immunity. Consequently, we found that malaria parasite infection could enhance the immune response of lung cancer DNA vaccine pcDNA3.1-hMUC1 and the combination produced a synergistic antitumor effect. CONCLUSIONS/SIGNIFICANCE: Malaria infection significantly suppresses LLC growth via induction of innate and adaptive antitumor responses in a mouse model. These data suggest that the malaria

  10. Antitumor Effect of Malaria Parasite Infection in a Murine Lewis Lung Cancer Model through Induction of Innate and Adaptive Immunity

    Science.gov (United States)

    Chen, Lili; He, Zhengxiang; Qin, Li; Li, Qinyan; Shi, Xibao; Zhao, Siting; Chen, Ling; Zhong, Nanshan; Chen, Xiaoping

    2011-01-01

    Background Lung cancer is the most common malignancy in humans and its high fatality means that no effective treatment is available. Developing new therapeutic strategies for lung cancer is urgently needed. Malaria has been reported to stimulate host immune responses, which are believed to be efficacious for combating some clinical cancers. This study is aimed to provide evidence that malaria parasite infection is therapeutic for lung cancer. Methodology/Principal Findings Antitumor effect of malaria infection was examined in both subcutaneously and intravenously implanted murine Lewis lung cancer (LLC) model. The results showed that malaria infection inhibited LLC growth and metastasis and prolonged the survival of tumor-bearing mice. Histological analysis of tumors from mice infected with malaria revealed that angiogenesis was inhibited, which correlated with increased terminal deoxynucleotidyl transferase-mediated (TUNEL) staining and decreased Ki-67 expression in tumors. Through natural killer (NK) cell cytotoxicity activity, cytokine assays, enzyme-linked immunospot assay, lymphocyte proliferation, and flow cytometry, we demonstrated that malaria infection provided anti-tumor effects by inducing both a potent anti-tumor innate immune response, including the secretion of IFN-γ and TNF-α and the activation of NK cells as well as adaptive anti-tumor immunity with increasing tumor-specific T-cell proliferation and cytolytic activity of CD8+ T cells. Notably, tumor-bearing mice infected with the parasite developed long-lasting and effective tumor-specific immunity. Consequently, we found that malaria parasite infection could enhance the immune response of lung cancer DNA vaccine pcDNA3.1-hMUC1 and the combination produced a synergistic antitumor effect. Conclusions/Significance Malaria infection significantly suppresses LLC growth via induction of innate and adaptive antitumor responses in a mouse model. These data suggest that the malaria parasite may provide a

  11. Phytochemical analysis and in vitro anthelmintic activity of Lophira lanceolata (Ochnaceae) on the bovine parasite Onchocerca ochengi and on drug resistant strains of the free-living nematode Caenorhabditis elegans.

    Science.gov (United States)

    Kalmobé, Justin; Ndjonka, Dieudonné; Boursou, Djafsia; Vildina, Jacqueline Dikti; Liebau, Eva

    2017-08-14

    Onchocerciasis is one of the tropical neglected diseases (NTDs) caused by the nematode Onchocerca volvulus. Control strategies currently in use rely on mass administration of ivermectin, which has marked activity against microfilariae. Furthermore, the development of resistance to ivermectin was observed. Since vaccine and safe macrofilaricidal treatment against onchocerciasis are still lacking, there is an urgent need to discover novel drugs. This study was undertaken to investigate the anthelmintic activity of Lophira lanceolata on the cattle parasite Onchocerca ochengi and the anthelmintic drug resistant strains of the free living nematode Caenorhabditis elegans and to determine the phytochemical profiles of the extracts and fractions of the plants. Plant was extracted in ethanol or methanol-methylene chloride. O. ochengi, C. elegans wild-type and C. elegans drug resistant strains were cultured in RPMI-1640 and NGM-agar respectively. Drugs diluted in dimethylsulphoxide/RPMI or M9-Buffer were added in assays and monitored at 48 h and 72 h. Worm viability was determined by using the MTT/formazan colorimetric method. Polyphenol, tannin and flavonoid contents were determined by dosage of gallic acid and rutin. Acute oral toxicity was evaluated using Swiss albino mice. Ethanolic and methanolic-methylene chloride extracts killed O. ochengi with LC 50 values of 9.76, 8.05, 6.39 μg/mL and 9.45, 7.95, 6.39 μg/mL respectively for leaves, trunk bark and root bark after 72 h. The lowest concentrations required to kill 50% of the wild-type of C. elegans were 1200 and 1890 μg/mL with ethanolic crude extract, 1000 and 2030 μg/mL with MeOH-CH 2 Cl 2 for root bark and trunk bark of L. lanceolata, respectively after 72 h. Leave extracts of L. lanceolata are lethal to albendazole and ivermectin resistant strains of C. elegans after 72 h. Methanol/methylene chloride extracted more metabolites. Additionally, extracts could be considered relatively safe. Ethanolic and

  12. Batwanema gen. n. and Chokwenema gen. n. (Oxyurida, Hystrignathidae), new nematode genera as parasites of Passalidae (Coleoptera) from the Democratic Republic of Congo

    Science.gov (United States)

    Morffe, Jans; García, Nayla

    2013-01-01

    Abstract Two new genera and species parasitizing passalid beetles from the Democratic Republic of Congo are described. Batwanema congo gen. n. et sp. n. is characterized by having females with the cervical cuticle armed with scale-like projections, arranged initially in rows of eight elements that gradually divide and form pointed spines toward the end of the spiny region, two cephalic annuli, clavate procorpus and genital tract monodelphic-prodelphic. Two Malagasian species of Artigasia Christie, 1934 were placed in this genus as B. latum (Van Waerebeke, 1973) comb. n. and B. annulatum (Van Waerebeke, 1973) comb. n. Chokwenema lepidophorum gen. n. et sp. n. is characterized by having females with the cervical cuticle armed with scale-like projections, arranged initially in rows of eight elements (similar to Batwanema) that divide gradually, forming spines; a single cephalic annule cone-like, truncated, moderately inflated; procorpus sub-cylindrical and genital tract didelphic-amphidelphic. PMID:24363593

  13. The Elusive Search for Reniform Nematode Resistance in Cotton.

    Science.gov (United States)

    Khanal, Churamani; McGawley, Edward C; Overstreet, Charles; Stetina, Salliana R

    2018-02-05

    The reniform nematode (Rotylenchulus reniformis Linford and Oliveira) has emerged as the most important plant-parasitic nematode of cotton in the United States cotton belt. Success in the development of reniform nematode-resistant upland cotton cultivars (Gossypium hirsutum L.) has not been realized despite over three decades of breeding efforts. Research approaches ranging from conventional breeding to triple species hybrids to marker-assisted selection have been employed to introgress reniform nematode resistance from other species of cotton into upland cultivars. Reniform nematode-resistant breeding lines derived from G. longicalyx were developed in 2007. However, these breeding lines displayed stunting symptoms and a hypersensitive response to reniform nematode infection. Subsequent breeding efforts focused on G. barbadense, G. aridum, G. armoreanum, and other species that have a high level of resistance to reniform nematode. Marker-assisted selection has greatly improved screening of reniform nematode-resistant lines. The use of advanced molecular techniques such as CRISPER-Cas9 systems and alternative ways such as delivery of suitable "cry" proteins and specific double-stranded RNA to nematodes will assist in developing resistant cultivars of cotton. In spite of the efforts of cotton breeders and nematologists, successes are limited only to the development of reniform nematode-resistant breeding lines. In this article, we provide an overview of the approaches employed to develop reniform nematode-resistant upland cotton cultivars in the past, progress to date, major obstacles, and some promising future research activity.

  14. First report of nematode parasites of Physalaemus santafecinus (Anura: Leiuperidae) from Corrientes, Argentina Primer registro de nematodos parásitos de Physalaemus santafecinus (Anura: Leiuperidae) de Corrientes, Argentina

    OpenAIRE

    Cynthya Elizabeth González; Monika Inés Hamann

    2010-01-01

    One hundred and eighty-three nematodes were recovered from 81 adults of leiuperid Physalaemus santafecinus examined from Corrientes, Argentina captured between January 2002 and December 2003. A total of 3 adults nematode species (Cosmocerca podicipinus, Cosmocerca parva, Aplectana hylambatis) and 1 larval species (Physaloptera sp.) were obtained. We present morphological characters, metric information and range for these nematode species and compared these with other specimens collected from ...

  15. PARASITIC INFECTION OF SYNODONTIS BATENSODA (RÜPPELL ...

    African Journals Online (AJOL)

    IYAJI

    2013-05-15

    May 15, 2013 ... Key words: Parasites, protozoan, helminths, nematodes, cestodes, acanthocephalans, Synodontis batensoda,. Rivers Niger-Benue Confluence, Nigeria. INTRODUCTION. Parasite communities of the tropical freshwater fishes are generalized as being isolationist, poor and of low diversity. (Kennedy et al.

  16. TABLE PREVALENCE OF GIT NEMATODES IN CATTLE

    African Journals Online (AJOL)

    User

    A study was carried out on the prevalence of gastrointestinal (GI) nematodes infection in naturally infected cattle in Ogbomoso area of Oyo State using standard parasitological techniques. The results indicated that out of the 1000 cattle examined, 30(3%) were infected and parasites identified were Haemonchus contortus.

  17. The G-protein γ subunit gpc-1 of the nematode C.elegans is involved in taste adaptation

    OpenAIRE

    Jansen, Gert; Weinkove, David; Plasterk, Ronald H.A.

    2002-01-01

    Caenorhabditis elegans has two heterotrimeric G-protein γ subunits, gpc-1 and gpc-2. Although GPC-1 is specifically expressed in sensory neurons, it is not essential for the detection of odorants or salts. To test whether GPC-1 is involved in sensory plasticity, we developed a water soluble compound adaptation assay. The behaviour of wild-type animals in this assay confirms that prolonged exposure to salts can abolish chemo-attraction to these compounds. This process is time and concentration...

  18. Tropical nematode diversity: vertical stratification of nematode communities in a Costa Rican humid lowland rainforest.

    Science.gov (United States)

    Powers, T O; Neher, D A; Mullin, P; Esquivel, A; Giblin-Davis, R M; Kanzaki, N; Stock, S P; Mora, M M; Uribe-Lorio, L

    2009-03-01

    Comparisons of nematode communities among ecosystems have indicated that, unlike many organisms, nematode communities have less diversity in the tropics than in temperate ecosystems. There are, however, few studies of tropical nematode diversity on which to base conclusions of global patterns of diversity. This study reports an attempt to estimate nematode diversity in the lowland tropical rainforest of La Selva Biological Research Station in Costa Rica. We suggest one reason that previous estimates of tropical nematode diversity were low is because habitats above the mineral soil are seldom sampled. As much as 62% of the overall genetic diversity, measured by an 18S ribosomal barcode, existed in litter and understorey habitats and not in soil. A maximum-likelihood tree of barcodes from 360 individual nematodes indicated most major terrestrial nematode lineages were represented in the samples. Estimated 'species' richness ranged from 464 to 502 within the four 40 x 40 m plots. Directed sampling of insects and their associated nematodes produced a second set of barcodes that were not recovered by habitat sampling, yet may constitute a major class of tropical nematode diversity. While the generation of novel nematode barcodes proved relatively easy, their identity remains obscure due to deficiencies in existing taxonomic databases. Specimens of Criconematina, a monophyletic group of soil-dwelling plant-parasitic nematodes were examined in detail to assess the steps necessary for associating barcodes with nominal species. Our results highlight the difficulties associated with studying poorly understood organisms in an understudied ecosystem using a destructive (i.e. barcode) sampling method.

  19. Rapid evolution of parasite life history traits on an expanding range-edge.

    Science.gov (United States)

    Kelehear, Crystal; Brown, Gregory P; Shine, Richard

    2012-04-01

    Parasites of invading species undergoing range advance may be exposed to powerful new selective forces. Low host density in range-edge populations hampers parasite transmission, requiring the parasite to survive longer periods in the external environment before encountering a potential host. These conditions should favour evolutionary shifts in offspring size to maximise parasite transmission. We conducted a common-garden experiment to compare life history traits among seven populations of the nematode lungworm (Rhabdias pseudosphaerocephala) spanning from the parasite population core to the expanding range-edge in invasive cane toads (Rhinella marina) in tropical Australia. Compared to conspecifics from the population core, nematodes from the range-edge exhibited larger eggs, larger free-living adults and larger infective larvae, and reduced age at maturity in parasitic adults. These results support a priori predictions regarding adaptive changes in offspring size as a function of invasion history, and suggest that parasite life history traits can evolve rapidly in response to the selective forces exerted by a biological invasion. © 2012 Blackwell Publishing Ltd/CNRS.

  20. Faecal egg counts and immune markers in a line of Scottish Cashmere goats selected for resistance to gastrointestinal nematode parasite infection.

    Science.gov (United States)

    McBean, David; Nath, Mintu; Kenyon, Fiona; Zile, Karina; Bartley, David J; Jackson, Frank

    2016-10-15

    This study aimed to investigate the effect of selection for low faecal egg count (FEC) in Scottish Cashmere goats in comparison to a control line of unselected goats grazing the same pasture. Goats from generations F2 through to F9 were monitored for FEC, bodyweight, peripheral eosinophilia and IgG, IgA and IgE response against Teladorsagia circumcincta from the end of their first grazing season, through winter housing (during which a single artificial challenge dose of 10,000 drug susceptible T. circumcincta was given) and the following full grazing season. The study demonstrated that selected line animals excreted a significantly lower number of parasite eggs (P0.05), although the selected line had significantly elevated or reduced levels (P<0.05) for all three within individual generations. There were significant associations between increased IgG and reduced FEC under artificial infection conditions (P=0.02). Increased IgA was also significantly associated with elevated FEC during the second grazing season (P<0.001). The study demonstrates that selection produced a line of goats with consistently reduced FEC compared with control animals, but did not identify a clear relationship between any of the immune markers measured and faecal egg output. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Microchip capillary electrophoresis-based genetic comparison of closely related cyathostomin nematode parasites of horses using randomly amplified polymorphic DNA polymerase chain reaction.

    Science.gov (United States)

    Posedi, Janez; Drögemüller, Michaela; Schnieder, Thomas; Höglund, Johan; Lichtenfels, J Ralph; von Samson-Himmelstjerna, Georg

    2004-03-01

    The microchip-based capillary electrophoresis technology represents a valuable recent development for the analysis of complex DNA banding patterns. We have used this technology for the differentiation of the closely related cyathostomin species Cylicocyclus elongatus and C. insigne from the horse. We found that the Agilent 2100 bioanalyser in combination with the DNA 7500 Lab Chip were suited to perform a phylogenetic DNA fingerprinting analysis of the parasite species studied. The analysis of the electrophoretic data was optimised and it was possible to resolve a phylogenetic tree where all 12 individual worms of the two Cylicocyclus species studied were assigned to their species as determined by microscopic identification based on morphological traits. Thus, our data indicated that the procedure described here provides an additional powerful tool that can be employed for species delineation of closely related strains or species, such as the two taxa of Cylicocyclus investigated in the present study. Furthermore, by determining the second internal transcribed spacer region of three and nine individual worms for C. elongatus and C. insigne, respectively, low intraspecific variations of only up to 0.3% were demonstrated.

  2. Long-term study of Sarcoptes scabiei infection in Norwegian red foxes (Vulpes vulpes) indicating host/parasite adaptation.

    Science.gov (United States)

    Davidson, Rebecca K; Bornstein, Set; Handeland, Kjell

    2008-10-01

    The red fox (Vulpes vulpes) population, in Norway, was naïve to Sarcoptes scabiei prior to the late 1970s when this parasite was first recorded and a still ongoing epidemic started. During the course of this protracted epidemic some degree of host/parasite adaptation, with the occurrence of healthy antibody positive foxes, might be expected. In the present study the prevalence of sarcoptic mange and serologically identified S. scabiei exposure was investigated in 363 Norwegian red foxes, shot by hunters during two different study periods (1994-1995 and 2002-2005). The sarcoptic mange diagnosis was based upon the presence of clearly visible lesions in the skin of the cadaver with confirmatory demonstration of S. scabiei. The serodiagnosis was based on an indirect-ELISA. There was a significant decrease in prevalence of both mange cases and seropositive animals from the first to the second study period. Whilst the mange prevalence fell more than threefold, from 30.0% to 6.6%, the seroprevalence dropped less dramatically from 53.3% to 19.1%. The smaller decrease in seroprevalence compared to mange cases reflected a significantly higher ratio of seropositive-mange negative versus seropositive-mange positive foxes, during the second study period, 40:18, compared to the first, 14:18. These findings indicate that the red fox population is adapting to live with the parasite and that low-grade or sub-clinical infections, and even recoveries, occur amongst exposed foxes. Mange positive foxes had significantly poorer body condition than those without sarcoptic mange. No significant difference in body condition was seen between seropositive-mange negative versus seronegative-mange negative foxes. The ELISA sensitivity was found to be 95% and proved a useful tool for investigating the exposure to S. scabiei in wild foxes. This study is believed to be the first pointing to a long-term Sarcoptes/fox adaptation, combining long-term prevalence studies of clinical sarcoptic mange

  3. Molecular contest between potato and the potato cyst nematode Globodera pallida: modulation of Gpa2-mediated resistance

    NARCIS (Netherlands)

    Koropacka, K.B.

    2010-01-01

    Gpa2 recognition specificity
    Among all the multicellular animals, nematodes are the most numerous. In soil, a high variety
    of free living nematodes feeding on bacteria can be found as well as species that parasitize
    insects, animals or plants. The potato cyst nematode (PCN)

  4. Eosinophils are important for protection, immunoregulation and pathology during infection with nematode microfilariae.

    Directory of Open Access Journals (Sweden)

    Emma T Cadman

    2014-03-01

    Full Text Available Eosinophil responses typify both allergic and parasitic helminth disease. In helminthic disease, the role of eosinophils can be both protective in immune responses and destructive in pathological responses. To investigate whether eosinophils are involved in both protection and pathology during filarial nematode infection, we explored the role of eosinophils and their granule proteins, eosinophil peroxidase (EPO and major basic protein-1 (MBP-1, during infection with Brugia malayi microfilariae. Using eosinophil-deficient mice (PHIL, we further clarify the role of eosinophils in clearance of microfilariae during primary, but not challenge infection in vivo. Deletion of EPO or MBP-1 alone was insufficient to abrogate parasite clearance suggesting that either these molecules are redundant or eosinophils act indirectly in parasite clearance via augmentation of other protective responses. Absence of eosinophils increased mast cell recruitment, but not other cell types, into the broncho-alveolar lavage fluid during challenge infection. In addition absence of eosinophils or EPO alone, augmented parasite-induced IgE responses, as measured by ELISA, demonstrating that eosinophils are involved in regulation of IgE. Whole body plethysmography indicated that nematode-induced changes in airway physiology were reduced in challenge infection in the absence of eosinophils and also during primary infection in the absence of EPO alone. However lack of eosinophils or MBP-1 actually increased goblet cell mucus production. We did not find any major differences in cytokine responses in the absence of eosinophils, EPO or MBP-1. These results reveal that eosinophils actively participate in regulation of IgE and goblet cell mucus production via granule secretion during nematode-induced pathology and highlight their importance both as effector cells, as damage-inducing cells and as supervisory cells that shape both innate and adaptive immunity.

  5. Chapter 42. Waterborne and Foodborne Parasites

    Science.gov (United States)

    This chapter identifies the most prominent parasites in North America that are acquired through contaminated food and water including protozoa (Acanthamoeba, Naegleria, Entamoeba, Giardia, Cryptosporidium, Cystoisospora, Cyclospora, Toxoplasma, and Balantidium), nematodes (Trichinella, Angiostrongyl...

  6. Population genomic structure and adaptation in the zoonotic malaria parasite Plasmodium knowlesi

    KAUST Repository

    Assefa, Samuel

    2015-10-06

    Malaria cases caused by the zoonotic parasite Plasmodium knowlesi are being increasingly reported throughout Southeast Asia and in travelers returning from the region. To test for evidence of signatures of selection or unusual population structure in this parasite, we surveyed genome sequence diversity in 48 clinical isolates recently sampled from Malaysian Borneo and in five lines maintained in laboratory rhesus macaques after isolation in the 1960s from Peninsular Malaysia and the Philippines. Overall genomewide nucleotide diversity (π = 6.03 × 10) was much higher than has been seen in worldwide samples of either of the major endemic malaria parasite species Plasmodium falciparum and Plasmodium vivax. A remarkable substructure is revealed within P. knowlesi, consisting of two major sympatric clusters of the clinical isolates and a third cluster comprising the laboratory isolates. There was deep differentiation between the two clusters of clinical isolates [mean genomewide fixation index (F) = 0.21, with 9,293 SNPs having fixed differences of F = 1.0]. This differentiation showed marked heterogeneity across the genome, with mean F values of different chromosomes ranging from 0.08 to 0.34 and with further significant variation across regions within several chromosomes. Analysis of the largest cluster (cluster 1, 38 isolates) indicated long-term population growth, with negatively skewed allele frequency distributions (genomewide average Tajima\\'s D = -1.35). Against this background there was evidence of balancing selection on particular genes, including the circumsporozoite protein (csp) gene, which had the top Tajima\\'s D value (1.57), and scans of haplotype homozygosity implicate several genomic regions as being under recent positive selection.

  7. Efecto de la micorrización sobre el crecimiento de plántulas de plátano en sustrato con y sin la presencia de nematodos fitoparásitos Effect of mycorrhization on the growth of plantain seedlings in substrate with and without the presence of plant parasitic nematodes

    Directory of Open Access Journals (Sweden)

    Lederson Gañán

    2011-12-01

    Full Text Available Se comparó el efecto de la pre-inoculación de los hongos micorrícicos arbusculares (HMA Glomus fistulosum, Glomus fasciculatum, micorriza comercial (G. aggregatum, G. manihotis, G. fistulosum, G. fasciculatum, Kuklosplora colombiana y Scutellospora spp. y un control sin HMA, sobre el crecimiento de propágulos vegetativos de plátano Dominico Hartón (Musa AAB en sustrato con la presencia de Radopholus similis y Helicotylenchus spp y sin ella. Adicionalmente se evaluó el efecto de los HMA sobre la cantidad final de los nematodos fitoparásitos en raíces y suelo rizosférico. Los resultados indicaron un incremento significativo en el porcentaje de colonización micorrícica en raíces inoculadas con HMA comercial (40% - 41%, en comparación con el control y los demás HMA (We compared the effect of pre-inoculation with the following arbuscular mycorrhizal fungi (AMF, on the growth of vegetative propagules (suckers of plantain (Musa AAB: 1 Glomus fistulosum, 2 Glomus fasciculatum, and 3 commercial inoculum (mixture of G. aggregatum, G. fistulosum, G.manihotis, G. fasciculatum, Kuklosplora colombiana and Scutellospora spp., compared with a control without AMF, in substrate with and without the presence of Radopholus similis and Helicotylenchus spp.. Furthermore, we evaluated the effect of AMF on the final amount of plant parasitic nematodes in roots and rhizosphere soil. The results indicated a significant intensification in the mycorrhizal colonization in roots inoculated with commercial inoculum of AMF (40 - 41% compared with control and other AMFs (<3%. There were over 30% of increase in fresh weight of roots and dry matter (corm and air tissue variables, in plants inoculated with commercial AMF, even in the presence of plant parasitic nematodes. The final amount of plant parasitic nematodes was not affected by the inoculation of AMF. We conclude that mycorrhizal fungi species’ mixture, present within the AMF commercial inoculum

  8. Helminth parasites of Clarias gariepinus and Tilapia zilli at Lamingo ...

    African Journals Online (AJOL)

    Three classes of parasites were recovered from both Clarias gariepinus and Tilapia zilli. A total of 399 parasites were recovered comprising 188 nematodes, 131 cestodes and 80 trematodes. A significant difference was observed in the parasite burden of the two fishes. KEYWORDS: Helminth parasites, fresh-water fishes, ...

  9. Tradition and transition: parasitic zoonoses of people and animals in Alaska, northern Canada, and Greenland.

    Science.gov (United States)

    Jenkins, Emily J; Castrodale, Louisa J; de Rosemond, Simone J C; Dixon, Brent R; Elmore, Stacey A; Gesy, Karen M; Hoberg, Eric P; Polley, Lydden; Schurer, Janna M; Simard, Manon; Thompson, R C Andrew

    2013-01-01

    Zoonotic parasites are important causes of endemic and emerging human disease in northern North America and Greenland (the North), where prevalence of some parasites is higher than in the general North American population. The North today is in transition, facing increased resource extraction, globalisation of trade and travel, and rapid and accelerating environmental change. This comprehensive review addresses the diversity, distribution, ecology, epidemiology, and significance of nine zoonotic parasites in animal and human populations in the North. Based on a qualitative risk assessment with criteria heavily weighted for human health, these zoonotic parasites are ranked, in the order of decreasing importance, as follows: Echinococcus multilocularis, Toxoplasma gondii, Trichinella and Giardia, Echinococcus granulosus/canadensis and Cryptosporidium, Toxocara, anisakid nematodes, and diphyllobothriid cestodes. Recent and future trends in the importance of these parasites for human health in the North are explored. For example, the incidence of human exposure to endemic helminth zoonoses (e.g. Diphyllobothrium, Trichinella, and Echinococcus) appears to be declining, while water-borne protozoans such as Giardia, Cryptosporidium, and Toxoplasma may be emerging causes of human disease in a warming North. Parasites that undergo temperature-dependent development in the environment (such as Toxoplasma, ascarid and anisakid nematodes, and diphyllobothriid cestodes) will likely undergo accelerated development in endemic areas and temperate-adapted strains/species will move north, resulting in faunal shifts. Food-borne pathogens (e.g. Trichinella, Toxoplasma, anisakid nematodes, and diphyllobothriid cestodes) may be increasingly important as animal products are exported from the North and tourists, workers, and domestic animals enter the North. Finally, key needs are identified to better assess and mitigate risks associated with zoonotic parasites, including enhanced

  10. Pulmonary, microbiological and hematological changes in Crotalus durissus terrificus (Serpentes, Viperidae parasitized by nematodes of the genus Rhabdias (Nematoda, Rhabdiasidae Alterações Pulmonares, microbiológicas e hematológicas em Crotalus durissus terrificus (Serpentes, Viperidae parasitadas pelos nematódeos do gênero Rhabdias (Nematoda, Rhabdiasidae

    Directory of Open Access Journals (Sweden)

    K.R. Santos

    2008-06-01

    Full Text Available This study reported the pulmonary, microbiological, and hematological alterations in Crotalus durissus terrificus parasitized by nematodes of the genus Rhabdias. Histological, microbiological, and hematological analysis were performed on parasitized (n=6 and non-parasitized (n=6 snakes. Granulocytic and mononuclear cell infiltrates in the pulmonary parenchyma and epithelium were also observed during the histological analysis of parasitized snakes. Microbiological analysis of parasitized animals revealed the following Gram-negative bacteria: Citrobacter divergens, Burkholderia cepacia, Stenotrophomonas maltophilia, Proteus vulgaris, Enterobacter sakazakii, Enterobacter ammnigenus, Pseudomonas aeruginosa, Pantoea sp. and Providencia rettgeri. In non-parasitized snakes, the following species were identified: B. cepacia, Pseudomonas fluorescens, and Acinetobacter baumanii. Increased levels of plasmatic protein, decreased lymphocyte counts, and normal red blood cell values were observed in parasitized animals.Este trabalho relata as alterações pulmonares, microbiológicas e hematológicas em Crotalus durissus terrificus parasitadas pelo nematódeo do gênero Rhabdias. As análises histológicas, microbiológicas e hematológicas foram realizadas em serpentes parasitadas (n=6 e não parasitadas (n=6. Foram observados infiltrados de células granulocíticas e mononucleares no parênquima pulmonar durante a análise histopatológica das serpentes parasitadas. A análise microbiológica revelou as seguintes bactérias Gram-negativas; Citrobacter divergens, Burkholderia cepacia, Stenotrophomonas maltophilia, Proteus vulgaris, Enterobacter sakazakii, Enterobacter ammnigenus, Pseudomonas aeruginosa, Pantoea sp. e Providencia rettgeri. Nas serpentes não parasitadas foram identificadas: B. cepacia, Pseudomonas fluorescens e Acinetobacter baumanii. Nos animais parasitados observaram-se: aumento da concentração de proteína plasmática, diminuição da

  11. Deep small RNA sequencing from the nematode Ascaris reveals conservation, functional diversification, and novel developmental profiles.

    Science.gov (United States)

    Wang, Jianbin; Czech, Benjamin; Crunk, Amanda; Wallace, Adam; Mitreva, Makedonka; Hannon, Gregory J; Davis, Richard E

    2011-09-01

    Eukaryotic cells express several classes of small RNAs that regulate gene expression and ensure genome maintenance. Endogenous siRNAs (endo-siRNAs) and Piwi-interacting RNAs (piRNAs) mainly control gene and transposon expression in the germline, while microRNAs (miRNAs) generally function in post-transcriptional gene silencing in both somatic and germline cells. To provide an evolutionary and developmental perspective on small RNA pathways in nematodes, we identified and characterized known and novel small RNA classes through gametogenesis and embryo development in the parasitic nematode Ascaris suum and compared them with known small RNAs of Caenorhabditis elegans. piRNAs, Piwi-clade Argonautes, and other proteins associated with the piRNA pathway have been lost in Ascaris. miRNAs are synthesized immediately after fertilization in utero, before pronuclear fusion, and before the first cleavage of the zygote. This is the earliest expression of small RNAs ever described at a developmental stage long thought to be transcriptionally quiescent. A comparison of the two classes of Ascaris endo-siRNAs, 22G-RNAs and 26G-RNAs, to those in C. elegans, suggests great diversification and plasticity in the use of small RNA pathways during spermatogenesis in different nematodes. Our data reveal conserved characteristics of nematode small RNAs as well as features unique to Ascaris that illustrate significant flexibility in the use of small RNAs pathways, some of which are likely an adaptation to Ascaris' life cycle and parasitism. The transcriptome assembly has been submitted to NCBI Transcriptome Shotgun Assembly Sequence Database(http://www.ncbi.nlm.nih.gov/genbank/TSA.html) under accession numbers JI163767–JI182837 and JI210738–JI257410.

  12. Evolution of plant parasitism in the phylum Nematoda.

    Science.gov (United States)

    Quist, Casper W; Smant, Geert; Helder, Johannes

    2015-01-01

    Within the species-rich and trophically diverse phylum Nematoda, at least four independent major lineages of plant parasites have evolved, and in at least one of these major lineages plant parasitism arose independently multiple times. Ribosomal DNA data, sequence information from nematode-produced, plant cell wall-modifying enzymes, and the morphology and origin of the style(t), a protrusible piercing device used to penetrate the plant cell wall, all suggest that facultative and obligate plant parasites originate from fungivorous ancestors. Data on the nature and diversification of plant cell wall-modifying enzymes point at multiple horizontal gene transfer events from soil bacteria to bacterivorous nematodes resulting in several distinct lineages of fungal or oomycete-feeding nematodes. Ribosomal DNA frameworks with sequence data from more than 2,700 nematode taxa combined with detailed morphological information allow for explicit hypotheses on the origin of agronomically important plant parasites, such as root-knot, cyst, and lesion nematodes.

  13. Functional morphology of parasitic isopods: understanding morphological adaptations of attachment and feeding structures in Nerocila as a pre-requisite for reconstructing the evolution of Cymothoidae

    Directory of Open Access Journals (Sweden)

    Christina Nagler

    2016-07-01

    Full Text Available Parasites significantly influence food webs and ecosystems and occur all over the world in almost every animal group. Within crustaceans there are numerous examples of ectoparasites; for example, representatives of the isopod group Cymothoidae. These obligatory parasitic isopods are relatively poorly studied regarding their functional morphology. Here we present new details of the morphological adaptations to parasitism of the cymothoiid ingroup Nerocila with up-to-date imaging methods (macro photography, stereo imaging, fluorescence photography, micro CT, and histology. Central aspects of the study were (1 the morphology of the mouthparts and (2 the attachment on the host, hence the morphology of the thoracopods. The mouthparts (labrum, mandibles, paragnaths, maxillulae, maxillae, maxillipeds form a distinct mouth cone and are most likely used for true sucking. The mouthparts are tightly “folded” around each other and provide functional rails for the only two moving mouthparts, mandible and maxillula. Both are not moving in an ancestral-type median-lateral movement, but are strongly tilted to move more in a proximal-distal axis. New details concerning the attachment demonstrate that the angular arrangement of the thoracopods is differentiated to impede removal by the host. The increased understanding of morphological adaptation to parasitism of modern forms will be useful in identifying disarticulated (not attached to the host fossil parasites.

  14. Halophilanema prolata n. gen., n. sp. (Nematoda: Allantonematidae, a parasite of the intertidal bug, Saldula laticollis (Reuter(Hemiptera: Saldidae on the Oregon coast

    Directory of Open Access Journals (Sweden)

    Poinar George O

    2012-02-01

    Full Text Available Abstract Background It is rare to find terrestrial nematode lineages parasitizing arthropods inhabiting the intertidal or littoral zone of the oceans. During an ecological study along the Oregon dunes, an allantonematid nematode (Tylenchomorpha: Allantonematidae was discovered parasitizing the intertidal shore bug, Saldula laticollis (Reuter(Hemiptera: Saldidae. This shore bug is adapted to an intertidal environment and can survive short periods of submergence during high tides. The present study describes the nematode parasite and discusses aspects of its development, ecology and evolution. Methods Adults and last instar nymphs of S. laticollis (Hemiptera: Saldidae were collected from the high intertidal zone among clumps of Juncus L. (Juncaceae plants at Waldport, Oregon on October 3, 2011. The bugs were dissected in 1% saline solution and the nematodes killed in 1% Ringers solution and immediately fixed in 5% formalin (at 20°C. Third stage juveniles removed from infected hosts were maintained in 1% saline solution until they matured to the adult stage, molted and mated. Results Halophilanema prolata n. gen., n. sp. (Nematoda: Allantonematidae is described from last instar nymphs and adults of the intertidal bug, Saldula laticollis on the Oregon coast. The new genus can be distinguished from other genera in the Allantonematidae by a stylet lacking basal knobs in both sexes, an excretory pore located behind the nerve ring, ribbed spicules, a gubernaculum, the absence of a bursa and the elongate-tubular shape of the ovoviviparous parasitic females. Studies of the organogenesis of Halophilanema showed development to third stage juveniles in the uterus of parasitic females. Maturation to the free-living adults and mating occurred in the environment. The incidence of infection of S. laticollis ranged from 0% to 85% depending on the microhabitat in the intertidal zone. Conclusions Based on the habitat and morphological characters, it is proposed

  15. Comparative proteomics of two life cycle stages of stable isotope-labeled Trypanosoma brucei reveals novel components of the parasite's host adaptation machinery.

    Science.gov (United States)

    Butter, Falk; Bucerius, Ferdinand; Michel, Margaux; Cicova, Zdenka; Mann, Matthias; Janzen, Christian J

    2013-01-01

    Trypanosoma brucei developed a sophisticated life cycle to adapt to different host environments. Although developmental differentiation of T. brucei has been the topic of intensive research for decades, the mechanisms responsible for adaptation to different host environments are not well understood. We developed stable isotope labeling by amino acids in cell culture in trypanosomes to compare the proteomes of two different life cycle stages. Quantitative comparison of 4364 protein groups identified many proteins previously not known to be stage-specifically expressed. The identification of stage-specific proteins helps to understand how parasites adapt to different hosts and provides new insights into differences in metabolism, gene regulation, and cell architecture. A DEAD-box RNA helicase, which is highly up-regulated in the bloodstream form of this parasite and which is essential for viability and proper cell cycle progression in this stage is described as an example.

  16. Inefficacy of albendazole sulphoxide and ivermectin for the treatment of bovine parasitic otitis caused by rhabditiform nematodes Ineficácia do sulfóxido de albendazole e da ivermectina no tratamento da otite parasitária bovina causada por nematóides rhabditiformes

    Directory of Open Access Journals (Sweden)

    Guilherme G. Verocai

    2009-11-01

    Full Text Available The purpose of this study was to evaluate the efficacy of orally administered albendazole sulphoxide and pour-on ivermectin for the treatment of bovine parasitic otitis caused by rhabditiform nematodes. Eighteen Gyr cows presenting clinical otitis were divided in three groups with six animals each. The first one did not receive any treatment (control group. The second one was treated with 0.5% pour-on ivermectin, 500µg/kg of body weight, and the third group was treated with oral 6% albendazole sulphoxide, at 6.0mg/kg. Both ear canals of each animal were reexamined on days 7 and 21 post treatment. The animals in the control group remained infected throughout the days of observation. Ivermectin treatment did not show effectiveness on days 7 or 21 post treatment. The albendazole sulphoxide treatment had an efficacy of 16.7 and 25% on days 7 and 21, respectively. Further studies are required to assess an effective treatment for this parasitic disease, especially via alternative administration routes, because of its significant impact on Bos taurus indicus cattle breeding in Tropical and Subtropical Regions.O objetivo deste estudo foi avaliar a eficácia do sulfóxido de albendazol administrado oralmente e da ivermectina "pour-on" no tratamento da otite parasitária bovina causada por nematóides rhabditiformes. Dezoito vacas Gir apresentando otite clínica foram divididas em três grupos de seis animais cada. O primeiro não recebeu tratamento (grupo controle. O segundo foi tratado com ivermectina "pour-on" a 0,05% na dose de 500µg/kg de peso vivo. O terceiro grupo foi tratado com sulfóxido de albendazol oral a 6% na dose 6,0mg/kg. Os condutos auditivos de todos os animais foram reexaminados nos dias 7 e 21 pós-tratamento. Os animais do grupo controle permaneceram infectados nos dias de observação. O tratamento com ivermectina não demonstrou eficácia alguma para os dias 7 e 21 pós-tratamento. O tratamento com sulfóxido de albendazol obteve

  17. Sexually Transmitted Parasitic Diseases

    OpenAIRE

    Shelton, Andrew A.

    2004-01-01

    An increasing number of diseases are recognized as being sexually transmitted. The majority of these are bacterial or viral in nature; however, several protozoan and nematode infections can also be transmitted by sexual activity. For most of these diseases, the primary mode of transmission is nonsexual in nature, but sexual activity that results in fecal-oral contact can lead to transmission of these agents. Two parasitic diseases commonly transmitted by sexual contact are amebiasis and giard...

  18. Proteins secreted by root-knot nematodes accumulate in the extracellular compartment during root infection

    OpenAIRE

    Rosso, Marie-Noëlle; Vieira, Paulo; de Almeida-Engler, Janice; Castagnone-Sereno, Philippe

    2011-01-01

    Root-knot nematodes are biotrophic parasites that invade the root apex of host plants and migrate towards the vascular cylinder where they induce the differentiation of root cells into hypertrophied multinucleated giant cells. Giant cells are part of the permanent feeding site required for nematode development into the adult stage. To date, a repertoire of candidate effectors potentially secreted by the nematode into the plant tissues to promote infection has been identified. However, the pre...

  19. Prevalence and intensity of infection with gastrointestinal nematodes in sheep in eastern Serbia

    OpenAIRE

    Kulišić, Z.; Aleksić, Nevenka; Đorđević, M.; Gajić, B.; Tambur, Z.; Stevanović, Jevrosima; Stanimirović, Z.

    2013-01-01

    A coprological examination of 680 grazing sheep was performed in Eastern Serbia from March 2011 to November 2012 in order to determine the presence of gastrointestinal (GI) nematode parasites. Fecal samples were randomly collected and examined by using qualitative and quantitative coprological techniques. It was found that 74.56% sheep were infected. Samples that contained nematode eggs were processed for larval development and eleven nematode genera were i...

  20. Transcriptome Analysis of Resistant and Susceptible Alfalfa Cultivars Infected With Root-Knot Nematode Meloidogyne incognita

    OpenAIRE

    Postnikova, Olga A.; Hult, Maria; Shao, Jonathan; Skantar, Andrea; Nemchinov, Lev G.

    2015-01-01

    Nematodes are one of the major limiting factors in alfalfa production. Root-knot nematodes (RKN, Meloidogyne spp.) are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to alfalfa fields. As of today, no studies have been published on global gene expression profiling in alfalfa infected with RKN or any other plant parasitic nematode. Very little information is available about molecular mechanisms that contribute...

  1. Product evaluation for reniform nematode suppression in Mississippi Delta sweetpotato production, 2011

    Science.gov (United States)

    The reniform nematode, Rotylenchulus reniformis, can cause significant losses in sweetpotato, Ipomoea batatas, production in the Mississippi Delta. Reniform nematode is a microscopic plant parasite that feeds on sweetpotato roots causing severe stunting of root growth. Reduction in yield due to the ...

  2. Sunn Hemp cover cropping and organic fertilizer effects on the nematode community under temperate growing conditions

    Science.gov (United States)

    Plantings of sunn hemp as a cover crop have been experimentally shown to improve soil health, reduce plant-parasitic nematodes, and increase nematode-antagonistic microorganisms. However, these studies have been largely conducted in tropical and subtropical regions. To investigate the impacts of sun...

  3. Evaluation of tomato genotypes for resistance to root-knot nematodes

    African Journals Online (AJOL)

    Tomato (Solanum lycopersicum) is one of the most popular vegetable crops worldwide, owing to its high nutritive value and diversified use. Tomato production in Ghana is threatened by plant parasitic nematodes, especially the root knot nematodes (Meloidogyne spp.), which are responsible for huge economic yield losses.

  4. HOW FUNGI INTERACT WITH NEMATODE TO ACTIVATE THE PLANT DEFENCE RESPONSE TO TOMATO PLANTS.

    Science.gov (United States)

    Leonetti, P; Costanza, A; Zonno, M C; Molinari, S; Altomare, C

    2014-01-01

    Management of plant parasitic nematodes with nematode predators, parasites or antagonists is an eco-friendly approach that may avoid the problems arisen by the use of toxic chemicals. Fungi belonging to Trichoderma spp. are well known in literature for their role in control of plant parasitic nematodes. Root-knot nematodes (RKNs), Meloidogyne spp., are obligate parasites that cause the formation of familiar galls on the roots of many cultivated plants. The interaction between the M. incognita motile second stage juveniles (J2s) and the isolate ITEM 908 of Trichoderma harzianum was examined in its effect on the nematode infestation level of susceptible tomato plants. To gain insight into the mechanisms by which ITEM 908 interacts with nematode-infected tomato plants, the expression patterns of the genes PR1 (marker of Salycilic Acid-depending resistance signalling pathway) and JERF3 (marker of the Jasmonic Acid/Ethylene-depending resistance signalling pathway) were detected over time in: i) untreated roots; ii) roots pre-treated with the fungus; iii) roots inoculated with the nematode; iv) pre-treated and inoculated roots. Infestation parameters were checked in untreated plants and plants treated with the fungus to test the effect of the fungus on nematode infestation level and to compare this effect with the expression of the genes PR1 and JERF3, involved in induced resistance.

  5. Heterodera schachtii Tyrosinase-like protein a novel nematode effector modulating plant hormone homeostasis

    Czech Academy of Sciences Publication Activity Database

    Habash, S.; Radakovic, Z.S.; Vaňková, Radomíra; Siddique, S.; Dobrev, Petre; Gleason, C.; Grundler, F.M.W.; Elashry, A.

    2017-01-01

    Roč. 7, JUL 31 (2017), č. článku 6874. ISSN 2045-2322 Institutional support: RVO:61389030 Keywords : arabidopsis-thaliana * cyst-nematode * parasitic nematode * transient expression * host plants * sequence * identification * infection * model * transformation Subject RIV: ED - Physiology OBOR OECD: Plant sciences, botany Impact factor: 4.259, year: 2016

  6. The significance of ecology in the development of Verticillium chlamydosporium as a biological control agent against root-knot nematodes (Meloidogyne spp.)

    NARCIS (Netherlands)

    Leij, de F.A.A.M.

    1992-01-01

    A thorough understanding of the interactions which occur between nematode parasites and nematode pests and the influence of biotic and abiotic factors on these interactions, is essential in the development of biological control agents for nematodes. The aim of this study was to develop a

  7. Two Entomophagous Isolated From Sumatera Utara; Potential as Biocontrol Agent Againts Nematode

    OpenAIRE

    Hastuti, Liana Dwi Sri; Nicklin, Jane; Siregar, Ameilia Zuliyanti

    2016-01-01

    Two species of nematophagous fungi has been isolated from Sumatera Utara soil, with an aim of harnessing their potential in the biological control of plant parasitic nematodes or animal parasitic nematodes in Indonesia, especially in Sumatera Utara. Soil samples were collected from tobacco plantations, vegetable fields and ornamental plantings in the Berastagi area, and also from livestock in local farms and a dairy farm in Berastagi Area, Karo Regency. Soil also collected from un-cultivated ...

  8. Studies on the parasites of cultured Oreochromis niloticus (Cichlidae ...

    African Journals Online (AJOL)

    The parasitic infection rates of cultured Oreochromis niloticus in earthened pond in South Eastern Nigeria was surveyed over a 12-month period (July 1999 - June 2000). Out of the 300 specimens examined, 106 (35.33%) were infected with one or more parasites. The parasites recovered were Nematodes: Procamallanus ...

  9. The Nematode Caenorhabditis Elegans.

    Science.gov (United States)

    Kenyon, Cynthia

    1988-01-01

    Discusses advantages of nematode use for studying patterns of cell division, differentiation, and morphogenesis. Describes nematode development. Cites experimental approaches available for genetic studies. Reviews the topics of control of cell division and differentiation, the nervous system, and muscle assembly and function of the organism. (RT)

  10. Nematode-Trapping Fungi.

    Science.gov (United States)

    Jiang, Xiangzhi; Xiang, Meichun; Liu, Xingzhong

    2017-01-01

    Nematode-trapping fungi are a unique and intriguing group of carnivorous microorganisms that can trap and digest nematodes by means of specialized trapping structures. They can develop diverse trapping devices, such as adhesive hyphae, adhesive knobs, adhesive networks, constricting rings, and nonconstricting rings. Nematode-trapping fungi have been found in all regions of the world, from the tropics to Antarctica, from terrestrial to aquatic ecosystems. They play an important ecological role in regulating nematode dynamics in soil. Molecular phylogenetic studies have shown that the majority of nematode-trapping fungi belong to a monophyletic group in the order Orbiliales (Ascomycota). Nematode-trapping fungi serve as an excellent model system for understanding fungal evolution and interaction between fungi and nematodes. With the development of molecular techniques and genome sequencing, their evolutionary origins and divergence, and the mechanisms underlying fungus-nematode interactions have been well studied. In recent decades, an increasing concern about the environmental hazards of using chemical nematicides has led to the application of these biological control agents as a rapidly developing component of crop protection.

  11. The role of cell wall-modifying proteins in plant penetration and feeding site proliferation by the potato cyst nematode Globodera rostochiensis

    NARCIS (Netherlands)

    Kudla, U.

    2006-01-01

    The main objective of this thesis was to investigate two distinct groups of proteins involved in plant cell walls modifications in the parasitism of the potato cyst nematode, Globodera rostochiensis , namely pectate lyases and expansins. Plant parasitism of potato cyst nematode proceeds through two

  12. Helminth parasites of indigenous chickens in Oodi, Kgatleng District, Botswana : short communication

    Directory of Open Access Journals (Sweden)

    E.Z. Mushi

    2000-07-01

    Full Text Available Thirteen adult indigenous chickens from Oodi, Kgatleng district, Botswana, were examined for helminth parasites. Two species of nematodes, Ascaridia galli and Heterakis gallinarum, and species of the cestode genus Raillietina, were recovered. A. galli and H. gallinarumwere the most commonly seen parasites. The nematode A. galli occurred concurrently with Raillietina spp.

  13. The significance of ecology in the development of Verticillium chlamydosporium as a biological control agent against root-knot nematodes (Meloidogyne spp.)

    OpenAIRE

    Leij, de, F.A.A.M.

    1992-01-01

    A thorough understanding of the interactions which occur between nematode parasites and nematode pests and the influence of biotic and abiotic factors on these interactions, is essential in the development of biological control agents for nematodes. The aim of this study was to develop a particular isolate of the nematophagous fungus Verticillium chlamydosporium as a biological control agent for root-knot nematodes. The work has gained insight into some of the ke...

  14. The importance, biology and management of cereal cyst nematodes (Heterodera spp.

    Directory of Open Access Journals (Sweden)

    F. Mokrini

    2018-01-01

    Full Text Available Cereals are exposed to biotic and abiotic stresses. Among the biotic stresses, plant-parasitic nematodes play an important role in decreasing crop yield. Cereal cyst nematodes (CCNs are known to be a major constraint to wheat production in several parts of the world. Significant economic losses due to CCNs have been reported. Recognition and identification of CCNs are the first steps in nematode management. This paper reviews the current distribution of CCNs in different parts of the world and the recent advances in nematode identification. The different approaches for managing CCNs are also discussed.

  15. A nematode that can manipulate the behaviour of slugs.

    Science.gov (United States)

    Morris, Alex; Green, Michael; Martin, Hayley; Crossland, Katie; Swaney, William T; Williamson, Sally M; Rae, Robbie

    2018-02-27

    The ability of parasites to manipulate the behaviour of their hosts has evolved multiple times, and has a clear fitness benefit to the parasite in terms of facilitating growth, reproduction and transfer to suitable hosts. The mechanisms by which these behavioural changes are induced are poorly understood, but in many cases parasite manipulation of serotonergic signalling in the host brain is implicated. Here we report that Phasmarhabditis hermaphrodita, a parasite of terrestrial gastropod molluscs, can alter the behaviour of slugs. Uninfected slugs (Deroceras panormitanum, Arion subfuscus and Arion hortensis) avoid areas where P. hermaphrodita is present, but slugs infected with P. hermaphrodita are more likely to be found where the nematodes are present. This ability is specific to P. hermaphrodita and other nematodes (Steinernema carpocapsae and Heterorhabditis bacteriophora) do not induce this behavioural change. To investigate how P. hermaphrodita changes slug behaviour we exposed slugs to fluoxetine (a selective serotonin reuptake inhibitor) and cyproheptadine (a serotonin receptor antagonist). Uninfected slugs fed fluoxetine no longer avoided areas where P. hermaphrodita was present; and conversely, infected slugs fed cyproheptadine showed no increased attraction to areas with nematodes. These findings suggest that a possible mechanism by whichP. hermaphrodita is able to manipulate parasite avoidance behaviour in host slugs is by manipulating serotonergic signalling in the brain, and that increased serotonin levels are potentially associated with a reduction in parasite avoidance. Copyright © 2018. Published by Elsevier B.V.

  16. Nematodes of elasmobranch fishes from the southern coast of Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo Knoff

    2001-01-01

    Full Text Available New records for nematode species recovered from elasmobranch fishes in Brazil are established and new systematical arrangements proposed. Parascarophis sphyrnae Campana-Rouget, 1955 from the spiral valve of Sphyrna zygaena is referred for the first time in South America as a new host record. Procamallanus (S. pereirai Annereaux, 1946, from the spiral valve of Raja castelnaui is reported parasitizing an elasmobranch host. Nematode larvae of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are listed from the stomach and spiral valves of several hosts. Anisakidae larvae previously referred in Brazil in the genus Phocanema should be reallocated in Pseudoterranova. Nematodes of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are reported for the first time parasitizing elasmobranchs in Brazil.

  17. Nematodes of elasmobranch fishes from the southern coast of Brazil.

    Science.gov (United States)

    Knoff, M; de São Clemente, S C; Pinto, R M; Gomes, D C

    2001-01-01

    New records for nematode species recovered from elasmobranch fishes in Brazil are established and new systematical arrangements proposed. Parascarophis sphyrnae Campana-Rouget, 1955 from the spiral valve of Sphyrna zygaena is referred for the first time in South America as a new host record. Procamallanus (S.) pereirai Annereaux, 1946, from the spiral valve of Raja castelnaui is reported parasitizing an elasmobranch host. Nematode larvae of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are listed from the stomach and spiral valves of several hosts. Anisakidae larvae previously referred in Brazil in the genus Phocanema should be reallocated in Pseudoterranova. Nematodes of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are reported for the first time parasitizing elasmobranchs in Brazil.

  18. Excretory/secretory products of anisakid nematodes

    DEFF Research Database (Denmark)

    Mehrdana, Foojan; Buchmann, Kurt

    2017-01-01

    Parasites from the family Anisakidae are widely distributed in marine fish populations worldwide and mainly nematodes of the three genera Anisakis, Pseudoterranova and Contracaecum have attracted attention due to their pathogenicity in humans. Their life cycles include invertebrates and fish...... as intermediate or transport hosts and mammals or birds as final hosts. Human consumption of raw or underprocessed seafood containing third stage larvae of anisakid parasites may elicit a gastrointestinal disease (anisakidosis) and allergic responses. Excretory and secretory (ES) compounds produced...... by the parasites are assumed to be key players in clinical manifestation of the disease in humans, but the molecules are likely to play a general biological role in invertebrates and lower vertebrates as well. ES products have several functions during infection, e.g. penetration of host tissues and evasion of host...

  19. PARASITIC INFECTION OF SYNODONTIS BATENSODA (RÜPPELL ...

    African Journals Online (AJOL)

    IYAJI

    2013-05-15

    Trichodinids), two ... Key words: Parasites, protozoan, helminths, nematodes, cestodes, acanthocephalans, Synodontis batensoda,. Rivers Niger-Benue ... including food and feeding habits have been carried out by several ...

  20. The dynamics of nematode infections of farmed ruminants

    NARCIS (Netherlands)

    Roberts, M.G.; Heesterbeek, J.A.P.

    1995-01-01

    In this paper the dynamics and control of nematode parasites of farmed ruminants are discussed via a qualitative analysis of a differential equation model. To achieve this a quantity, 'the basic reproduction quotient' (Q0), whose definition coincides with previous definitions of R0 for

  1. Reproduction of root knot nematode (Meloidogyne incognita) on Bt ...

    African Journals Online (AJOL)

    SARAH

    2013-09-30

    Sep 30, 2013 ... ABSTRACT. Objective: The sedentary endoparasite Meloidogyne incognita is an important plant parasitic nematode that infects cotton causing significant yield losses. The objective of this study was to evaluate reproduction of M. incognita in Bt cotton (06Z604D), isoline (99M03) and HART 89M (local ...

  2. Gastrointestinal nematodes of donkeys in and around Alage, South ...

    African Journals Online (AJOL)

    of lugol's iodine was added to the sediment to differentiate the larvae which stains the free living nematode yellow, while parasitic 3rd stage larvae remain unstained. The larvae was then identified under low power microscopy (10x objective), based on the shape and number of gut cells, relative size of sheath tail and shape ...

  3. The diversity and evolution of nematodes (Pharyngodonidae) infecting New Zealand lizards.

    Science.gov (United States)

    Mockett, Sarah; Bell, Trent; Poulin, Robert; Jorge, Fátima

    2017-04-01

    Host-parasite co-evolutionary studies can shed light on diversity and the processes that shape it. Molecular methods have proven to be an indispensable tool in this task, often uncovering unseen diversity. This study used two nuclear markers (18S rRNA and 28S rRNA) and one mitochondrial (cytochrome oxidase subunit I) marker to investigate the diversity of nematodes of the family Pharyngodonidae parasitizing New Zealand (NZ) lizards (lygosomine skinks and diplodactylid geckos) and to explore their co-evolutionary history. A Bayesian approach was used to infer phylogenetic relationships of the parasitic nematodes. Analyses revealed that nematodes parasitizing skinks, currently classified as Skrjabinodon, are more closely related to Spauligodon than to Skrjabinodon infecting NZ geckos. Genetic analyses also uncovered previously undetected diversity within NZ gecko nematodes and provided evidence for several provisionally cryptic species. We also examined the level of host-parasite phylogenetic congruence using a global-fit approach. Significant congruence was detected between gecko-Skrjabinodon phylogenies, but our results indicated that strict co-speciation is not the main co-evolutionary process shaping the associations between NZ skinks and geckos and their parasitic nematodes. However, further sampling is required to fully resolve co-phylogenetic patterns of diversification in this host-parasite system.

  4. Functional Characterization of a Novel Class of Morantel-Sensitive Acetylcholine Receptors in Nematodes.

    Directory of Open Access Journals (Sweden)

    Elise Courtot

    2015-12-01

    Full Text Available Acetylcholine receptors are pentameric ligand-gated channels involved in excitatory neuro-transmission in both vertebrates and invertebrates. In nematodes, they represent major targets for cholinergic agonist or antagonist anthelmintic drugs. Despite the large diversity of acetylcholine-receptor subunit genes present in nematodes, only a few receptor subtypes have been characterized so far. Interestingly, parasitic nematodes affecting human or animal health possess two closely related members of this gene family, acr-26 and acr-27 that are essentially absent in free-living or plant parasitic species. Using the pathogenic parasitic nematode of ruminants, Haemonchus contortus, as a model, we found that Hco-ACR-26 and Hco-ACR-27 are co-expressed in body muscle cells. We demonstrated that co-expression of Hco-ACR-26 and Hco-ACR-27 in Xenopus laevis oocytes led to the functional expression of an acetylcholine-receptor highly sensitive to the anthelmintics morantel and pyrantel. Importantly we also reported that ACR-26 and ACR-27, from the distantly related parasitic nematode of horses, Parascaris equorum, also formed a functional acetylcholine-receptor highly sensitive to these two drugs. In Caenorhabditis elegans, a free-living model nematode, we demonstrated that heterologous expression of the H. contortus and P. equorum receptors drastically increased its sensitivity to morantel and pyrantel, mirroring the pharmacological properties observed in Xenopus oocytes. Our results are the first to describe significant molecular determinants of a novel class of nematode body wall muscle AChR.

  5. Malaria parasites: the great escape

    Directory of Open Access Journals (Sweden)

    Laurent Rénia

    2016-11-01

    Full Text Available Parasites of the genus Plasmodium have a complex life cycle. They alternate between their final mosquito host and their intermediate hosts. The parasite can be either extra- or intracellular, depending on the stage of development. By modifying their shape, motility, and metabolic requirements, the parasite adapts to the different environments in their different hosts. The parasite has evolved to escape the multiple immune mechanisms in the host that try to block parasite development at the different stages of their development. In this article, we describe the mechanisms reported thus far that allow the Plasmodium parasite to evade innate and adaptive immune responses.

  6. Plant nematodes in South Africa. 11. Checklist of plant nematodes of the protected areas of KwaZulu-Natal

    Directory of Open Access Journals (Sweden)

    Mariette Marais

    2013-03-01

    Full Text Available Nematodes are some of the most abundant soil organisms and are an essential part of soil ecology. These organisms are used as indicator organisms and can be linked to soil health. Biological collections contain vast amounts of data, with the National Collection of Nematodes housed at the Plant Protection Research Institute, Agricultural Research Council being no different. During the digitising of the collection a number of unpublished records of plant nematodes reported from protected areas in KwaZulu-Natal were found in the South African Plant-Parasitic Nematode Survey database. A total of 222 plant nematode species belonging to 39 genera were reported from the province, with only 94 of these species reported from the protected areas and 172 and 159 species reported from uncultivated (outside the protected areas and cultivated areas, respectively. Only nine species, Criconema silvum, Criconema talanum, Helicotylenchus marethae, Ogma dracomontanum, Ogma louisi, Ogma ueckermanni, Paralongidorus deborae, Trichodorus rinae and Xiphinemella marindae were described from protected areas, whilst O. dracomontanum, P. deborae and T. rinae were subsequently also reported from other provinces. Conservation implications: A higher degree of diversity of nematodes was observed in the unprotected areas of the province. The observation suggests that nematode fauna, and by implication also other invertebrates, are not adequately protected.

  7. Benzimidazole-resistant gastrointestinal nematodes in indigenous Chiapas and Pelibuey sheep breeds from Chiapas, Mexico.

    Science.gov (United States)

    Liébano-Hernández, E; González-Olvera, M; Vázquez-Peláez, C; Mendoza-de-Gives, P; Ramírez-Vargas, G; Peralta-Lailson, M; Reyes-García, M E; Osorio, J; Sánchez-Pineda, H; López-Arellano, M E

    2015-01-01

    Because of the natural adaptation of Mexican sheep, the aim of the present study was to identify the presence or absence of gastrointestinal parasitic nematodes (GIN) resistant to benzimidazole (BZ) in both Chiapas and Pelibuey sheep breeds on local farms. Both male and female GIN-infected grazing sheep of the two breeds were selected. Sheep faecal samples were collected to obtain infective larvae (L3). This evolving stage of the parasite was used for taxonomic identification of the genus, based on its morphological characteristics. BZ anthelmintic resistance was evaluated using a nematode-compound in vitro interaction bioassay and the allele-specific polymerase chain reaction technique to detect mutations of residues 198 and 200 on isotype 1 of the β-tubulin gene. Three BZ-based compounds (febendazole (FBZ), tiabendazole (TBZ) and albendazole (ABZ)) at concentrations of 1, 0.5, 0.25, 0.125, 0.062 and 0.03 mg/ml were used to estimate the anthelmintic efficacy and lethal dose (LD50, LD90 and LD99) of the drugs. Two parasitic nematodes, Haemonchus and Teladorsagia, were identified in both isolates. Also, the proportions of anthelmintic resistance identified in GIN of the two sheep breeds were 68% in isolates from the Chiapas breed and 71.8% in the Pelibuey breed. The specific lethal activity obtained with FBZ was higher than 90%. However, TBZ and ABZ showed a lethal activity lower than 50%. High variability in the discriminating dose values was found among the BZ drugs. For example, FBZ LD ranged from 0.01 to 1.20 mg/ml; on the other hand, TBZ and ABZ required a dose ranging from 0.178 to 759 mg/ml. In addition, amino acid changes of Phe (TTC) to Tyr (TAC) at codon 200 of the β-tubulin gene, showing resistance to BZ, and no changes at codon 198 Glu (GAA) to Ala (GCA) were observed for both isolates. These results confirmed the presence of a genetic mutation associated with BZ in both Chiapas and Pelibuey nematode isolates.

  8. Karyotype and reproduction mode of the rodent parasite Strongyloides venezuelensis

    OpenAIRE

    HINO, AKINA; TANAKA, TERUHISA; TAKAISHI, MAHO; FUJII, YUMIKO; PALOMARES-RIUS, JUAN E.; HASEGAWA, KOICHI; MARUYAMA, HARUHIKO; KIKUCHI, TAISEI

    2014-01-01

    SUMMARY Strongyloides venezuelensis is a parasitic nematode that infects rodents. Although Strongyloides species described to date are known to exhibit parthenogenetic reproduction in the parasitic stage of their life cycle and sexual reproduction in the free-living stage, we did not observe any free-living males in S. venezuelensis in our strain, suggesting that the nematode is likely to depend on parthenogenetic reproduction. We confirmed by cytological analysis that S. venezuelensis produc...

  9. On the track of the Red Queen: bark beetles, their nematodes, local climate and geographic parthenogenesis.

    Science.gov (United States)

    Meirmans, S; Skorping, A; Løyning, M K; Kirkendall, L R

    2006-11-01

    Geographic parthenogenesis has been explained as resulting from parasite pressure (Red Queen hypothesis): several studies have found high degrees of sexuals where the prevalence of parasites is high. However, it is important to address whether prevalence of parasites mirrors risk of infection. We explored geographic parthenogenesis of Ips acuminatus bark beetles and their nematodes. Local climate is crucial for nematode stages outside the host, in spring and summer, and prevalence should thus be associated with those temperatures if prevalence reliably reflects exposure risk across populations. This was the case; however, high prevalence of a virulent nematode species was not associated with many sexuals, whereas highly sexual populations were characterized by high infection risk of benign nematodes. Low virulence of the latter makes Red Queen dynamics unlikely. Geographical patterns of parthenogenesis were instead associated with winter temperature and variance in temperature.

  10. The genome, transcriptome, and proteome of the nematode Steinernema carpocapsae: evolutionary signatures of a pathogenic lifestyle.

    Science.gov (United States)

    Rougon-Cardoso, Alejandra; Flores-Ponce, Mitzi; Ramos-Aboites, Hilda Eréndira; Martínez-Guerrero, Christian Eduardo; Hao, You-Jin; Cunha, Luis; Rodríguez-Martínez, Jonathan Alejandro; Ovando-Vázquez, Cesaré; Bermúdez-Barrientos, José Roberto; Abreu-Goodger, Cei; Chavarría-Hernández, Norberto; Simões, Nelson; Montiel, Rafael

    2016-11-23

    The entomopathogenic nematode Steinernema carpocapsae has been widely used for the biological control of insect pests. It shares a symbiotic relationship with the bacterium Xenorhabdus nematophila, and is emerging as a genetic model to study symbiosis and pathogenesis. We obtained a high-quality draft of the nematode's genome comprising 84,613,633 bp in 347 scaffolds, with an N50 of 1.24 Mb. To improve annotation, we sequenced both short and long RNA and conducted shotgun proteomic analyses. S. carpocapsae shares orthologous genes with other parasitic nematodes that are absent in the free-living nematode C. elegans, it has ncRNA families that are enriched in parasites, and expresses proteins putatively associated with parasitism and pathogenesis, suggesting an active role for the nematode during the pathogenic process. Host and parasites might engage in a co-evolutionary arms-race dynamic with genes participating in their interaction showing signatures of positive selection. Our analyses indicate that the consequence of this arms race is better characterized by positive selection altering specific functions instead of just increasing the number of positively selected genes, adding a new perspective to these co-evolutionary theories. We identified a protein, ATAD-3, that suggests a relevant role for mitochondrial function in the evolution and mechanisms of nematode parasitism.

  11. Soil nematode community under the non-native trees in the Botanic Garden of Petrozavodsk State University

    Directory of Open Access Journals (Sweden)

    Sushchuk Anna

    2016-12-01

    Full Text Available The particularities of soil nematode communities of the rhizosphere of non-native trees were studied in the Botanic Garden of Petrozavodsk State University (Republic of Karelia. Taxonomic diversity, abundance, community structure and ecological indices derived from nematode fauna analysis were used as the evaluation parameters. Nematode fauna included 51 genera, 6 of them were plant parasitic. The dominant eco-trophic group in the nematode community structure of coniferous trees was bacterial feeders; fungal feeders in most cases were observed in the second numbers. The contribution of bacterial feeders was decreased and plant parasites were increased in eco-trophic structure of nematode communities of deciduous trees in compared with coniferous trees. Analysis of ecological indices showed that the state of soil nematode communities reflects complex, structured (stable soil food web in the biocenoses with deciduous trees, and degraded (basal food web – under coniferous trees.

  12. Stomach nematodes (Mastophorus Muris) in rats (Rattus rattus) are associated with coconut (Cocos nucifera) Habitat at palmyra atoll

    Science.gov (United States)

    Lafferty, K.D.; Hathaway, S.A.; Wegmann, A.S.; Shipley, F.S.; Backlin, A.R.; Helm, J.; Fisher, R.N.

    2010-01-01

    Black rats (Rattus rattus) and their stomach nematodes (Mastophorus muris) were historically introduced to islets at Palmyra Atoll in the central Pacific Line Islands. To investigate patterns of parasitism, we trapped rats and quantified nematodes on 13 islets of various sizes and habitat types. Most rats were parasitized (59) with an average of 12 worms per infected rat. Islet size did not greatly influence parasite population biology. Nematodes also did not appear to affect rat condition (weight to skull length). The only strong and consistent factor associated with the mean abundance of nematodes in rats was habitat (dominant cover and locally dominant plant species). Thus, nematodes were much more abundant in rats from sites dominated by coconut trees (Cocos nucifera). Coconut trees may also be an introduced species at Palmyra Atoll. ?? American Society of Parasitologists 2010.

  13. Stomach nematodes (Mastophorus muris) in rats (Rattus rattus) are associated with coconut (Cocos nucifera) habitat at Palmyra Atoll.

    Science.gov (United States)

    Lafferty, Kevin D; Hathaway, Stacie A; Wegmann, Alex S; Shipley, Frank S; Backlin, Adam R; Helm, Joel; Fisher, Robert N

    2010-02-01

    Black rats ( Rattus rattus ) and their stomach nematodes (Mastophorus muris) were historically introduced to islets at Palmyra Atoll in the central Pacific Line Islands. To investigate patterns of parasitism, we trapped rats and quantified nematodes on 13 islets of various sizes and habitat types. Most rats were parasitized (59%) with an average of 12 worms per infected rat. Islet size did not greatly influence parasite population biology. Nematodes also did not appear to affect rat condition (weight to skull length). The only strong and consistent factor associated with the mean abundance of nematodes in rats was habitat (dominant cover and locally dominant plant species). Thus, nematodes were much more abundant in rats from sites dominated by coconut trees (Cocos nucifera). Coconut trees may also be an introduced species at Palmyra Atoll.

  14. Parasitic zoonotic diseases in Turkey

    Directory of Open Access Journals (Sweden)

    Nazmiye Altintas

    2008-12-01

    Full Text Available Zoonoses and zoonotic diseases are becoming more common and they are now receiving increased attention across the world. Zoonotic parasites are found in a wide variety of protozoa, cestodes, nematodes, trematodes and arthropods worldwide and many zoonotic parasites have assumed an important role. The importance of some parasitic zoonoses has increased in recent years due to the fact that they can be agents of opportunistic infections. Although a number of zoonotic parasites are often found and do cause serious illnesses in Turkey, some are more common and these diseases are more important as they cause serious public health problems, such as leishmaniasis, toxoplasmosis, cryptosporidiosis, echinococcosis, trichinellosis and toxocariasis. Information on these zoonotic diseases is provided here as these are the most important zoonotic parasitic diseases in Turkey.

  15. Analysis of nematode motion using an improved light-scatter based system.

    Directory of Open Access Journals (Sweden)

    Chuck S Nutting

    2015-02-01

    Full Text Available The detailed assessment of nematode activity and viability still remains a relatively undeveloped area of biological and medical research. Computer-based approaches to assessing the motility of larger nematode stages have been developed, yet these lack the capability to detect and analyze the more subtle and important characteristics of the motion of nematodes. There is currently a need to improved methods of assessing the viability and health of parasitic worms.We describe here a system that converts the motion of nematodes through a light-scattering system into an electrical waveform, and allows for reproducible, and wholly non-subjective, assessment of alterations in motion, as well as estimation of the number of nematode worms of different forms and sizes. Here we have used Brugia sp. microfilariae (L1, infective larvae (L3 and adults, together with the free-living nematode Caenorhabditis elegans.The motion of worms in a small (200 ul volume can be detected, with the presence of immotile worms not interfering with the readings at practical levels (up to at least 500 L1 /200 ul. Alterations in the frequency of parasite movement following the application of the anti-parasitic drugs, (chloroquine and imatinib; the anti-filarial effect of the latter agent is the first demonstrated here for the first time. This system can also be used to estimate the number of parasites, and shortens the time required to estimate parasites numbers, and eliminates the need for microscopes and trained technicians to provide an estimate of microfilarial sample sizes up to 1000 parasites/ml. Alterations in the form of motion of the worms can also be depicted.This new instrument, named a "WiggleTron", offers exciting opportunities to further study nematode biology and to aid drug discovery, as well as contributing to a rapid estimate of parasite numbers in various biological samples.

  16. Behaviour of Heterodera glycines and Meloidogyne incognita infective juveniles exposed to nematode FMRFamide-like peptides in vitro

    Science.gov (United States)

    Plant-parasitic nematodes depend upon a family of neuropeptides, the FMRFamide-like peptides (FLPs), to regulate locomotion and behavior. To exploit FLPs as leads to novel nematode control agents, an understanding of how specific FLPs affect behavior, and what differences exist between species, is i...

  17. Nasonia Parasitic Wasps Escape from Haller's Rule by Diphasic, Partially Isometric Brain-Body Size Scaling and Selective Neuropil Adaptations

    NARCIS (Netherlands)

    Groothuis, Jitte; Smid, Hans M.

    2017-01-01

    Haller's rule states that brains scale allometrically with body size in all animals, meaning that relative brain size increases with decreasing body size. This rule applies both on inter- and intraspecific comparisons. Only 1 species, the extremely small parasitic wasp Trichogramma evanescens, is

  18. Prevalence of Strongylida nematodes associated with African Snail, Achatina fulica, in Valle del Cauca, Colombia

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    Diego Córdoba-R

    2017-09-01

    Full Text Available Objectives. To establish the presence and prevalence of Strongylida nematode parasites in Achatina fulica in the Valle del Cauca, especially of nematodes that are potentially pathogenic for humans. Materials and methods. A. fulica individuals were collected in nine cities of the Valle del Cauca, Colombia. Direct visual examination was used to identify A. fulica parasites. Nematodes were separated from tissue or collected from mucus, washed in saline solution, and fixed in a hot AFA solution. Samples were mounted in glycerine and observed under the microscope. Results. The general nematode parasite prevalence was 35% in 2013. The city with highest prevalence during 2013 was Cartago (60%, following by Buenaventura (42.9% and Cali (33%, while during 2014 were Cali (30% and Buenaventura (30%. The Strongylida nematodes registered were classified in three genera: Angiostrongylus (14.7% prevalence, Aelurostrongylus (2.6%,and Strongyluris (2.6%. The city with highest positive records of Angiostrongylus was Cali during 2014 and Aelurostrongylus was Buenaventura during 2013. Strongyluris genus was recorded only in Cali during 2013, with a prevalence of 11%. Of the nine evaluated cities, five has presence of Angiostrongylus. Conclusions. Three genera of Strongylida nematode were recorded associated with A. fulicas specimens in the Valle del Cauca during 2013 and 2014. Therefore, the role that A. fulica and native mollusk species could be playing in the life cycle of these parasites at the local level should not underestimated.

  19. Activated entomopathogenic nematode infective juveniles release lethal venom proteins.

    Directory of Open Access Journals (Sweden)

    Dihong Lu

    2017-04-01

    Full Text Available Entomopathogenic nematodes (EPNs are unique parasites due to their symbiosis with entomopathogenic bacteria and their ability to kill insect hosts quickly after infection. It is widely believed that EPNs rely on their bacterial partners for killing hosts. Here we disproved this theory by demonstrating that the in vitro activated infective juveniles (IJs of Steinernema carpocapsae (a well-studied EPN species release venom proteins that are lethal to several insects including Drosophila melanogaster. We confirmed that the in vitro activation is a good approximation of the in vivo process by comparing the transcriptomes of individual in vitro and in vivo activated IJs. We further analyzed the transcriptomes of non-activated and activated IJs and revealed a dramatic shift in gene expression during IJ activation. We also analyzed the venom proteome using mass spectrometry. Among the 472 venom proteins, proteases and protease inhibitors are especially abundant, and toxin-related proteins such as Shk domain-containing proteins and fatty acid- and retinol-binding proteins are also detected, which are potential candidates for suppressing the host immune system. Many of the venom proteins have conserved orthologs in vertebrate-parasitic nematodes and are differentially expressed during IJ activation, suggesting conserved functions in nematode parasitism. In summary, our findings strongly support a new model that S. carpocapsae and likely other Steinernema EPNs have a more active role in contributing to the pathogenicity of the nematode-bacterium complex than simply relying on their symbiotic bacteria. Furthermore, we propose that EPNs are a good model system for investigating vertebrate- and human-parasitic nematodes, especially regarding the function of excretory/secretory products.

  20. Nematofauna associada à cultura do quiabo na região leste de Minas Gerais The influence of parasitic nematodes on okra crop in eastern Minas Gerais State, Brazil

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    Rosângela D'Arc de Lima Oliveira

    2007-03-01

    Full Text Available A cultura do quiabo possui importância sócio-cultural para o estado de Minas Gerais (MG e 34,2% do volume de quiabo comercializado na Ceasa/Contagem procede dos municípios localizados entre Caratinga e Governador Valadares. Entretanto, o quiabeiro tem a sua produção influenciada pelos danos decorrentes de infecções causadas pelos nematóides das galhas (Meloidogyne spp.. As principais espécies desse nematóide que atacam o quiabeiro já foram relatadas no Brasil, e algumas destas podem causar a morte da planta. A correta identificação da(s espécie(s e, ou da(s raça(s de Meloidogyne presente(s nas raízes do quiabeiro é importante na escolha da medida de controle mais apropriada. Para determinar a ocorrência e distribuição de Meloidogyne spp. e outros nematóides na região leste de MG, 70 amostras de solo e raízes da cultura, provenientes de 14 localidades, foram avaliadas por características morfológicas e isoenzimáticas. Dentre as populações de Meloidogyne spp. identificadas prevaleceu M. incognita (fenótipos de Esterase I1 e I2, seguida de M. javanica (fenótipos J2 e J3 e M. arenaria (fenótipo A2. A espécie M. mayaguensis foi confirmada pela ocorrência do fenótipo M2 para esterase, N3 para malato desidrogenase, N2 para superóxido dismutase e N3 para glutamato-oxaloacetato transaminase. Este é o primeiro relato da ocorrência de M. mayaguensis em MG. Outros nematóides detectados na rizosfera do quiabeiro foram Aphelenchus sp., Criconemella sp., Helicotylenchus spp., Pratylenchus brachyurus e P. coffeae, Rotylenchulus reniformis, Rotylenchus sp., Tylenchus sp. e Tylenchorhynchus sp.Okra has a cultural and social importance for the State of Minas Gerais (MG, and 34,2% of the volume marketed in the Ceasa/Contagem, MG, come from the municipalities located near Caratinga and Governador Valadares. The okra production is influenced for the infection caused by the root-knot nematodes (Meloidogyne spp.. The main species

  1. Paradigms for parasite conservation.

    Science.gov (United States)

    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

  2. Analysis of the Transcriptome of the Infective Stage of the Beet Cyst Nematode, H. schachtii.

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    John Fosu-Nyarko

    Full Text Available The beet cyst nematode, Heterodera schachtii, is a major root pest that significantly impacts the yield of sugar beet, brassicas and related species. There has been limited molecular characterisation of this important plant pathogen: to identify target genes for its control the transcriptome of the pre-parasitic J2 stage of H. schachtii was sequenced using Roche GS FLX. Ninety seven percent of reads (i.e., 387,668 with an average PHRED score > 22 were assembled with CAP3 and CLC Genomics Workbench into 37,345 and 47,263 contigs, respectively. The transcripts were annotated by comparing with gene and genomic sequences of other nematodes and annotated proteins on public databases. The annotated transcripts were much more similar to sequences of Heterodera glycines than to those of Globodera pallida and root knot nematodes (Meloidogyne spp.. Analysis of these transcripts showed that a subset of 2,918 transcripts was common to free-living and plant parasitic nematodes suggesting that this subset is involved in general nematode metabolism and development. A set of 148 contigs and 183 singletons encoding putative homologues of effectors previously characterised for plant parasitic nematodes were also identified: these are known to be important for parasitism of host plants during migration through tissues or feeding from cells or are thought to be involved in evasion or modulation of host defences. In addition, the presence of sequences from a nematode virus is suggested. The sequencing and annotation of this transcriptome significantly adds to the genetic data available for H. schachtii, and identifies genes primed to undertake required roles in the critical pre-parasitic and early post-parasitic J2 stages. These data provide new information for identifying potential gene targets for future protection of susceptible crops against H. schachtii.

  3. Analysis of the Transcriptome of the Infective Stage of the Beet Cyst Nematode, H. schachtii.

    Science.gov (United States)

    Fosu-Nyarko, John; Nicol, Paul; Naz, Fareeha; Gill, Reetinder; Jones, Michael G K

    2016-01-01

    The beet cyst nematode, Heterodera schachtii, is a major root pest that significantly impacts the yield of sugar beet, brassicas and related species. There has been limited molecular characterisation of this important plant pathogen: to identify target genes for its control the transcriptome of the pre-parasitic J2 stage of H. schachtii was sequenced using Roche GS FLX. Ninety seven percent of reads (i.e., 387,668) with an average PHRED score > 22 were assembled with CAP3 and CLC Genomics Workbench into 37,345 and 47,263 contigs, respectively. The transcripts were annotated by comparing with gene and genomic sequences of other nematodes and annotated proteins on public databases. The annotated transcripts were much more similar to sequences of Heterodera glycines than to those of Globodera pallida and root knot nematodes (Meloidogyne spp.). Analysis of these transcripts showed that a subset of 2,918 transcripts was common to free-living and plant parasitic nematodes suggesting that this subset is involved in general nematode metabolism and development. A set of 148 contigs and 183 singletons encoding putative homologues of effectors previously characterised for plant parasitic nematodes were also identified: these are known to be important for parasitism of host plants during migration through tissues or feeding from cells or are thought to be involved in evasion or modulation of host defences. In addition, the presence of sequences from a nematode virus is suggested. The sequencing and annotation of this transcriptome significantly adds to the genetic data available for H. schachtii, and identifies genes primed to undertake required roles in the critical pre-parasitic and early post-parasitic J2 stages. These data provide new information for identifying potential gene targets for future protection of susceptible crops against H. schachtii.

  4. The spatial habitat structure of host populations explains the pattern of rejection behavior in hosts and parasitic adaptations in cuckoos

    Czech Academy of Sciences Publication Activity Database

    Roskaft, E.; Moksnes, A.; Stokke, B. G.; Moskát, C.; Honza, Marcel

    2002-01-01

    Roč. 13, č. 2 (2002), s. 163-168 ISSN 1045-2249 R&D Projects: GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6093917 Keywords : Cuculus canorus * habitat structure * brood parasitism Subject RIV: EG - Zoology Impact factor: 2.449, year: 2002 http://beheco.oxfordjournals.org/ cgi /reprint/13/2/163. pdf

  5. Characterization of three novel fatty acid- and retinoid-binding protein genes (Ha-far-1, Ha-far-2 and Hf-far-1) from the cereal cyst nematodes Heterodera avenae and H. filipjevi

    Science.gov (United States)

    Heterodera avenae and H. filipjevi are major parasites of wheat, reducing production worldwide. Both are sedentary endoparasitic nematodes, and their development and parasitism depend strongly on nutrients obtained from hosts. Secreted fatty acid- and retinoid-binding (FAR) proteins are nematode-spe...

  6. Parasitic Diseases

    Science.gov (United States)

    ... a bug bite, or sexual contact. Some parasitic diseases are easily treated and some are not. Parasites ... be seen with the naked eye. Some parasitic diseases occur in the United States. Contaminated water supplies ...

  7. Parasites of Clarias gariepinus (Burchell, 1822) (pisces: Clariidae ...

    African Journals Online (AJOL)

    Seventeen species of parasites were recovered from 1071 Clarias gariepinus examined from the Mwanza Gulf of Lake Victoria. The parasite fauna comprised of four ectoparasites, a Monogenea, Hirudinea, crustacean and a Digenea; and fourteen endoparasites, five nematodes, five trematodes and three cestodes. Twelve ...

  8. Preliminary studies of the helminth parasites of Limicolaria Aurora in ...

    African Journals Online (AJOL)

    Specimens of Limicolaria aurora collected from Ile-Ife area were surveyed for infection with parasitic helminthes. The snails were picked from bushes and dissected and examined in the laboratory. Four different helminth parasites comprising of 3 nematodes and a digenetic trematode were observed in L. aurora.

  9. Gastrointestinal Parasites of Pigs in a Commercial Farm in Isiala ...

    African Journals Online (AJOL)

    The helminth parasite groups encountered were nematodes 64 (64.0%) and trematodes 15 (15.0%). The parasites identified were Gastrodiscus aegyptiacus, Oesophagostomum dentatum, Trichuris suis, Stephanurus dentatus, Metastronggylus salmi, and Ascaris suum. Stephanuru dentatus had the highest prevalence rate ...

  10. Parasitic Gastroenteritis (PGE) Complex of Domestic Ruminants in ...

    African Journals Online (AJOL)

    Parasitic gastro-enteritis (PGE) is a major health problem and thus the main constraint on the profitable production of domestic ruminants in Nigeria. An annual loss of 60 million Naira due to the disease in domestic ruminants has been estimated. Parasitic gastro-enteritis is a complex of diseases involving several nematode ...

  11. Evolution of Plant Parasitism in the Phylum Nematoda

    NARCIS (Netherlands)

    Quist, C.W.; Smant, G.; Helder, J.

    2015-01-01

    Within the species-rich and trophically diverse phylum Nematoda, at least four independent major lineages of plant parasites have evolved, and in at least one of these major lineages plant parasitism arose independently multiple times. Ribosomal DNA data, sequence information from nematode-produced,

  12. Nematóides do Brasil. Parte V: nematóides de mamíferos Brazillan nematodes. Part V: nematodes of mammals

    Directory of Open Access Journals (Sweden)

    Joaquim Júlio Vicente

    1997-01-01

    Full Text Available A survey of nematode species parasitizing Brazilian mammals is presented, with enough data to provide their specific identification. The tirst section refers to the survey ofthe species, related to 21 superfamilies, 45 families, 160 genera and 495 species that are illustrated and measurement tables are given. The second section is concerned to the catalogue ofhost mammals which includes 34 families, 176 species and their respective parasite nematodes. The identification of these helminths is achieved by means of keys to the superfamilies, families and genera. Specific determination is induced through the figures and tables as above mentioned.

  13. Discovery of filarial nematode DNA in Amblyomma americanum in Northern Virginia.

    Science.gov (United States)

    Henning, Tyler C; Orr, John M; Smith, Joshua D; Arias, Jorge R; Rasgon, Jason L; Norris, Douglas E

    2016-03-01

    Ticks collected in 2011 were screened for the presence of filarial nematode genetic material, and positive samples were sequenced for analysis. Monanema-like filarial nematode DNA was recently discovered in Amblyomma americanum in northern Virginia, marking the first time genetic material from this parasite has been discovered in ticks in the state. Phylogenetic analysis revealed that this material was directly related to a previously discovered filarial nematode in A. americanum populations in Maryland as well as recently identified parasites in Ixodes scapularis from southern Connecticut. Further study is warranted to visually confirm the presence of these nematodes, characterize their distribution, and determine if these ticks are intermediate hosts. Copyright © 2015 Elsevier GmbH. All rights reserved.

  14. Parasites of selected reptiles of the National Zoological Garden, Sri Lanka.

    Science.gov (United States)

    Fernando, Saminda P; Udagama-Randeniya, Preethi V

    2009-06-01

    The National Zoological Garden plays a vital role in conservation of reptiles in Sri Lanka. Since parasitic infestations of captive reptiles can impact their health, a survey for intestinal parasites and ectoparasites was conducted on 19 selected reptilian species (14 snakes, four chelonians, and one crocodilian) housed at the National Zoological Garden, Sri Lanka. Of the reptiles screened, 62% (N = 139) were infected with parasites; 66% and 24% exclusively harbored intestinal and ecto parasites, respectively, while 10% carried both types of parasites. Three ticks (Ixodidae), two adult cestodes, plerocercoid larvae, and four nematode species were recovered during this survey. Three types of nematode ova and a single type of digenian ova, protozoan cysts, L3 nematode larvae, and a protozoan were detected in the feces. In this first systematic survey of reptilian parasites in Sri Lanka, four new host-parasite records are documented.

  15. Some nematodes of freshwater fishes in Venezuela.

    Science.gov (United States)

    Moravec, F; Prouza, A; Royero, R

    1997-01-01

    The present paper comprises a systematic survey of nematodes found in 88 specimens of 24 species of freshwater fishes in Venezuela in 1992 and 1994. The following 13 species of nematodes were recorded: Adults; Guyanema longispiculum Moravec, Prouza et Royero, 1996, Guyanema sp., Procamallanus (Spirocamallanus) inopinatus Travassos, Artigas et Pereira, 1928, P. (S.) krameri (Petter, 1974) comb. n., P.(S.) pintoi (Kohn et Fernandes, 1988) comb, n., Procamallanus (Spirocamallanus) sp., Raphidascaris (Sprentascaris) mahnerti (Petter et Cassone, 1984). Larvae: Anisakidae gen. sp., Brevimulticaecum sp., Contracaecum sp. Type 1, Contracaecum sp. Type 2, Contracaecum sp. Type 3, Eustrongylides sp. All these parasites are reported from Venezuela for the first time and all findings represent new host records. Brevimulticaecum larvae are reported from fishes for the first time. Almost all parasites are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. A new name, Terranova diazungriai nom.nov. is proposed for T. caballeroi Díaz-Ungría, 1968 (a junior homonym of T. caballeroi Barus et Coy Otero, 1966).

  16. Unique structure and regulation of the nematode detoxification gene regulator SKN-1: implications to understanding and controlling drug resistance

    Science.gov (United States)

    Choe, Keith P.; Leung, Chi K.; Miyamoto, Michael M.

    2012-01-01

    Nematodes parasitize an alarming number of people and agricultural animals globally and cause debilitating morbidity and mortality. Anthelmintics have been the primary tools used to control parasitic nematodes for the past several decades, but drug resistance is becoming a major obstacle. Xenobiotic detoxification pathways defend against drugs and other foreign chemicals in diverse organisms, and evidence is accumulating that they play a role in mediating resistance to anthelmintics in nematodes. Related anti-oxidation pathways may also provide filarial parasites protection against host free radical-mediated immune responses. Upstream regulatory pathways have received almost no attention in nematode parasites despite their potential to co-regulate multiple detoxification and anti-oxidation genes. The NRF2 transcription factor mediates inducible detoxification and anti-oxidation defenses in mammals and recent studies have demonstrated that it promotes multidrug resistance in some human tumors. Recent studies in the free-living model nematode Caenorhabditis elegans have defined the homologous transcription factor SKN-1 as a master regulator of detoxification and anti-oxidation genes. Despite similar functions, SKN-1 and NRF2 have important differences in structure and regulatory pathways. Protein alignment and phylogenetic analyses indicate that these differences are shared among many nematodes making SKN-1 a candidate for specifically targeting nematode detoxification and anti-oxidation. PMID:22656429

  17. Assessment of parasitic load in goat through the examination of faecal matter

    OpenAIRE

    Kumar Rajesh, Singh, B.P. and Patil, S.S.

    2017-01-01

    Parasitic infection do not show heavy rate of mortality, however there occurrence being chronic, most of the time leads to serious production losses, this led to study about severity of parasitic load and type of parasitic infection in goats. Parasitic infection most of the time leads to serious production losses. Gastrointestinal nematodes are ubiquitous parasites of grazing ruminants and cause decreases in survival, live weight gain, wool and milk production and reproduction performance. Pa...

  18. THE PREVALENCE OF GASTROINTESTINAL NEMATODES OF BALI CATTLE BREEDERS IN NUSA PENIDA

    Directory of Open Access Journals (Sweden)

    Putu Agus Trisna Kusuma Antara

    2017-08-01

    Full Text Available Nusa Penida is a pure breeding area of bali cattle, in which the cattle are mainly kept in conventional maintenance system and potentially infected by parasite, especially gastrointestinal nematodes. This study aims were to determine the prevalence and type of gastrointestinal nematodes in bali cattle breeders in Nusa Penida. Fecal samples were taken from 50 bali cattle breeders kept in cages (simantri and another 50 samples were from cattle not kept in cage. The floating method was used for morphological examination and prevalence, the data was analyzed with descriptive analysis. The results showed, the prevalence of bovine gastrointestinal nematodes in Nusa Penida was 25%. The prevalence of nematode infection in bali cattle that kept cages was lower compared to the cattle that were not kept in cage. Strongyloides papillosus and Capillaria bovis were the gastrointestinal nematodes found in the infected cattle.

  19. Interactions Between Nutrition and Infections With Haemonchus contortus and Related Gastrointestinal Nematodes in Small Ruminants.

    Science.gov (United States)

    Hoste, H; Torres-Acosta, J F J; Quijada, J; Chan-Perez, I; Dakheel, M M; Kommuru, D S; Mueller-Harvey, I; Terrill, T H

    2016-01-01

    Interactions between host nutrition and feeding behaviour are central to understanding the pathophysiological consequences of infections of the digestive tract with parasitic nematodes. The manipulation of host nutrition provides useful options to control gastrointestinal nematodes as a component of an integrated strategy. Focussed mainly on the Haemonchus contortus infection model in small ruminants, this chapter (1) illustrates the relationship between quantitative (macro- and micro-nutrients) and qualitative (plant secondary metabolites) aspects of host nutrition and nematode infection, and (2) shows how basic studies aimed at addressing some generic questions can help to provide solutions, despite the considerable diversity of epidemiological situations and breeding systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Gastric nematodes of Nile crocodiles, Crocodylus niloticus Laurenti, 1768, in the Okavango River, Botswana

    Directory of Open Access Journals (Sweden)

    K. Junker

    2006-09-01

    Full Text Available The ascaridoid nematodes Dujardinascaris madagascariensis Chabaud & Caballero, 1966, Dujardinascaris dujardini (Travassos, 1920, Gedoelstascaris vandenbrandeni (Baylis, 1929 Sprent, 1978 and Multicaecum agile (Wedl, 1861 Baylis, 1923 were recovered from the stomach contents of Crocodylus niloticus Laurenti, 1768 from the Okavango River, Botswana, together with Eustrongylides sp., a dioctophymatoid nematode usually parasitizing piscivorous birds. Dujardinascaris madagascariensis was present in most of the infected hosts, while the remaining species were mostly represented in single collections in one to three hosts. All four ascaridoid nematodes represent new geographic records.

  1. Spatiotemporal analysis of predation by carabid beetles (Carabidae on nematode infected and uninfected slugs in the field.

    Directory of Open Access Journals (Sweden)

    Bjørn Arild Hatteland

    Full Text Available The dynamics of predation on parasites within prey has received relatively little attention despite the profound effects this is likely to have on both prey and parasite numbers and hence on biological control programmes where parasites are employed. The nematode Phasmarhabditis hermaphrodita is a commercially available biological agent against slugs. Predation on these slugs may, at the same time, result in intraguild predation on slug-parasitic nematodes. This study describes, for the first time, predation by carabid beetles on slugs and their nematode parasites on both spatial and temporal scales, using PCR-based methods. The highest nematode infection levels were found in the slugs Deroceras reticulatum and Arion silvaticus. Numbers of infected slugs decreased over time and no infected slugs were found four months after nematode application. The density of the most abundant slug, the invasive Arion vulgaris, was positively related to the activity-density of the carabid beetle, Carabus nemoralis. Predation on slugs was density and size related, with highest predation levels also on A. vulgaris. Predation on A. vulgaris decreased significantly in summer when these slugs were larger than one gram. Predation by C. nemoralis on slugs was opportunistic, without any preferences for specific species. Intraguild predation on the nematodes was low, suggesting that carabid beetles such as C. nemoralis probably do not have a significant impact on the success of biological control using P. hermaphrodita.

  2. Palaeosymbiosis revealed by genomic fossils of Wolbachia in a strongyloidean nematode.

    Directory of Open Access Journals (Sweden)

    Georgios Koutsovoulos

    2014-06-01

    Full Text Available Wolbachia are common endosymbionts of terrestrial arthropods, and are also found in nematodes: the animal-parasitic filaria, and the plant-parasite Radopholus similis. Lateral transfer of Wolbachia DNA to the host genome is common. We generated a draft genome sequence for the strongyloidean nematode parasite Dictyocaulus viviparus, the cattle lungworm. In the assembly, we identified nearly 1 Mb of sequence with similarity to Wolbachia. The fragments were unlikely to derive from a live Wolbachia infection: most were short, and the genes were disabled through inactivating mutations. Many fragments were co-assembled with definitively nematode-derived sequence. We found limited evidence of expression of the Wolbachia-derived genes. The D. viviparus Wolbachia genes were most similar to filarial strains and strains from the host-promiscuous clade F. We conclude that D. viviparus was infected by Wolbachia in the past, and that clade F-like symbionts may have been the source of filarial Wolbachia infections.

  3. Respiratory nematodes in cat populations of Italy.

    Science.gov (United States)

    Di Cesare, Angela; Veronesi, Fabrizia; Grillotti, Eleonora; Manzocchi, Simone; Perrucci, Stefania; Beraldo, Paola; Cazzin, Stefania; De Liberato, Claudio; Barros, Luciano A; Simonato, Giulia; Traversa, Donato

    2015-12-01

    The occurrence of common respiratory parasites of domestic cats (the metastrongyloid "cat lungworm" Aelurostrongylus abstrusus and the trichuroid Capillaria aerophila) and of neglected respiratory nematodes of felids (Troglostrongylus brevior, Angiostrongylus chabaudi and Oslerus rostratus) was here evaluated in two and three geographical sites of Northern and Central Italy, respectively. In 2014-2015, individual fecal samples of 868 domestic cats were examined microscopically and genetically, and epidemiological data related to parasitic infections were evaluated as possible risk factors by binary logistic regression models. The most common parasite was A. abstrusus in both mono- and poli-specific infections, followed by T. brevior and C. aerophila, while cats scored negative for other parasites. Cats positive for A. abstrusus (1.9-17 % infection rate) and C. aerophila (0.9-4.8 % infection rate) were found in all examined sites, while cats scored positive for T. brevior (1-14.3 % infection rate) in four sites. Also, T. brevior was here found for the first time in a domestic cat from a mountainous area of Northern Italy. The occurrence of lungworms was statistically related to the presence of respiratory signs and more significant in cats with mixed infection by other lungworms and/or intestinal parasites. Cats living in site C of Central Italy resulted statistically more at risk of infection for lungworms than cats living in the other study sites, while animals ageing less than 1 year were at more risk for troglostrongylosis. Finally, the presence of lungworms was more significant in cats with mixed infection by other lungworms and/or intestinal parasites. These results are discussed under epidemiological and clinical points of views.

  4. The Role of Costimulatory Molecules in the Development of Memory and Effector T Helper 2 Cells During an in vivo Immune Response to the Murine Gastrointestinal Parasite Heligmosomoides polygyrus

    National Research Council Canada - National Science Library

    Ekkens, Melinda

    2002-01-01

    ...+ T cell differentiation is not well understood. One model used to study the Th immune response involves oral infection of mice with the gastrointestinal nematode parasite Heligmosomoides polygyrus...

  5. Soy desiccants herbicides acting in nematode populations on community land

    Directory of Open Access Journals (Sweden)

    Lucas Baiochi Riboldi

    2013-12-01

    Full Text Available The use of herbicides is the main method of weed control in soybeans. Desiccants are also being used routinely to anticipate the harvest and / or minimize the deterioration of seed quality. There is the possibility of direct or indirect contact with such pesticides, affect the community of nematodes in the soil. However, such effects and their magnitudes are yet to be clarified, especially in the case of selective herbicides. Thus, the objective of this study was to evaluate the use of selective herbicides in soybean on nematodes harmful to the crop. The experiment was conducted with transgenic soybean (‘M-SOY 7908RR’. The experimental design was a randomized block design with the following treatments: paraquat (400 g a.i ha-1, diquat (200 g a.i ha-1, a mixture of paraquat and diquat (300 + 150 g a.i ha-1, two doses of carfentrazone ethyl (20 g a.i ha-1 and 30 g a.i ha-1 and control (without desiccant application. The nematode community in the area was monitored in four periods. In none of those was found significant variation in the populations of nematodes harmful to soybeans, due to the application of any of desiccants. However, especially in the last sampling time, the desiccant application always resulted in increased populations of free-living nematodes and parasites those considered weak for soybean.

  6. Current status for gastrointestinal nematode diagnosis in small ruminants: where are we and where are we going?

    Science.gov (United States)

    Preston, Sarah Jane Margaret; Sandeman, Mark; Gonzalez, Jorge; Piedrafita, David

    2014-01-01

    Gastrointestinal nematode (GIN) parasites pose a significant economic burden particularly in small ruminant production systems. Anthelmintic resistance is a serious concern to the effective control of GIN parasites and has fuelled the focus to design and promote sustainable control of practices of parasite control. Many facets of sustainable GIN parasite control programs rely on the ability to diagnose infection both qualitatively and quantitatively. Diagnostics are required to determine anthelmintic efficacies, for targeted treatment programs and selection of animals for parasite resistant breeding. This review describes much of the research investigated to date to improve the current diagnostic for the above practices which is based on counting the number of parasite eggs in faeces.

  7. Molecular characterization of the Drosophila responses towards nematodes

    OpenAIRE

    Arefin, Md. Badrul

    2016-01-01

    A sophisticated evolutionary conserved innate immune system has evolved in insects to fight pathogens and to restrict damage in harmful (danger) situations including cancer. A significant amount of knowledge about different infection models in Drosophila has been generated in past decades, which revealed functional resemblances and implications for vertebrate systems. However, how Drosophila responds towards multicellular parasitic nematodes and in danger situations is still little understood...

  8. Co-evolution between Globodera rostochiensis and potato driving sequence diversity of NB-LRR resistance loci and nematode suppressors of plant immunity

    OpenAIRE

    Finkers-Tomczak, A.M.

    2011-01-01

    Sedentary plant parasitic nematodes have evolved sophisticated strategies that allow them to transform host cells in the roots of host plants into feeding structures. These complex structures enable the nematodes to complete their life cycle inside a single host plant. Feeding structure initiation and maintenance are thought to be determined by the concerted action of effectors produced by the esophageal glands of the nematodes. However, the molecular mechanisms underlying the transformation ...

  9. Identification, Validation and Utilization of Novel Nematode-Responsive Root-Specific Promoters in Arabidopsis for Inducing Host-Delivered RNAi Mediated Root-Knot Nematode Resistance

    Directory of Open Access Journals (Sweden)

    Atul Kakrana

    2017-12-01

    Full Text Available The root-knot nematode (RKN, Meloidogyne incognita, is an obligate, sedentary endoparasite that infects a large number of crops and severely affects productivity. The commonly used nematode control strategies have their own limitations. Of late, RNA interference (RNAi has become a popular approach for the development of nematode resistance in plants. Transgenic crops capable of expressing dsRNAs, specifically in roots for disrupting the parasitic process, offer an effective and efficient means of producing resistant crops. We identified nematode-responsive and root-specific (NRRS promoters by using microarray data from the public domain and known conserved cis-elements. A set of 51 NRRS genes was identified which was narrowed down further on the basis of presence of cis-elements combined with minimal expression in the absence of nematode infection. The comparative analysis of promoters from the enriched NRRS set, along with earlier reported nematode-responsive genes, led to the identification of specific cis-elements. The promoters of two candidate genes were used to generate transgenic plants harboring promoter GUS constructs and tested in planta against nematodes. Both promoters showed preferential expression upon nematode infection, exclusively in the root in one and galls in the other. One of these NRRS promoters was used to drive the expression of splicing factor, a nematode-specific gene, for generating host-delivered RNAi-mediated nematode-resistant plants. Transgenic lines expressing dsRNA of splicing factor under the NRRS promoter exhibited upto a 32% reduction in number of galls compared to control plants.

  10. Blood parasites of penguins: a critical review.

    Science.gov (United States)

    Vanstreels, Ralph Eric Thijl; Braga, Érika Martins; Catão-Dias, José Luiz

    2016-07-01

    Blood parasites are considered some of the most significant pathogens for the conservation of penguins, due to the considerable morbidity and mortality they have been shown to produce in captive and wild populations of these birds. Parasites known to occur in the blood of penguins include haemosporidian protozoans (Plasmodium, Leucocytozoon, Haemoproteus), piroplamid protozoans (Babesia), kinetoplastid protozoans (Trypanosoma), spirochete bacteria (Borrelia) and nematode microfilariae. This review provides a critical and comprehensive assessment of the current knowledge on these parasites, providing an overview of their biology, host and geographic distribution, epidemiology, pathology and implications for public health and conservation.

  11. The nematode Goezia sp. (Anisakidae) from Bagrus bayad (Osteichthyes) from Egypt.

    Science.gov (United States)

    El Alfi, Nadia M

    2005-04-01

    The present study describes nematode infection in the freshwater fish Bagrus bayad (Osteichthyes) collected from the Red Sea at Suez Canal Zone. Of 32 examined fish, 21 (65%) were infected with Goezia sp. (Nematoda: Family: Anisakidae) with mean ntensity of 4.1 parasites. The nematode present here differs from Goezia braziliensis, G. breviaeca and G. intermedia, as well as from other species described. The main difference was in the greater number of pre-anal papillae in males compared to G. braziliensis. The present parasite also differs from G. braziliensis in spicule length and distance of vulva from the anterior extremity.

  12. The role of IgG1 hypergammaglobulinaemia in immunity to the gastrointestinal nematode Nematospiroides dubius. The immunochemical purification, antigen-specificity and in vivo anti-parasite effect of IgG1 from immune serum.

    Science.gov (United States)

    Pritchard, D I; Williams, D J; Behnke, J M; Lee, T D

    1983-06-01

    Nematospiroides dubius, in common with many other species of metazoan parasite, induces an IgG1 hypergammaglobulinaemia during the course of infection. In the present study, immune sera raised in CFLP mice by repeated infection contained 24 ng/ml IgG1 compared with a resting level of 2.4 mg/ml. IgG2a and IgG2b levels were depressed following infection from 1.5 to 0.6 mg/ml and 0.64 to 0.42 mg/ml respectively. IgM levels were unaltered by infection (0.16 mg/ml) whilst IgA levels increased from 0.7 to 1.2 mg/ml. Immunochemical fractionation of immune sera by a combination of affinity chromatography and gel filtration revealed that the anti-parasite activity of the original serum could be largely accounted for by purified IgG1 fractions as assessed by immunoprecipitin and immunofluorescence assays. Purified IgG1 was shown to react with antigenic components common to both adult homogenate and adult excretory-secretory antigen. In addition, absorption studies revealed that as much as 48% of purified IgG1 from immune serum reacted with adult N. dubius antigen. In vivo, IgG1 was the only purified immunoglobulin isotype to cause significant reduction in worm numbers in the gastrointestinal tract when administered alone, and to have any noticeable co-operative effect when administered in conjunction with immune mesenteric lymph node cells. IgG1 also caused severe stunting of worms, and promoted the adherence of peritoneal exudate cells to the worm surface in vitro. It is suggested that one mechanism by which immune mesenteric lymph-node cells exert their protective activity following cell transfer is by elevating IgG1 levels in recipient mice.

  13. RNAseq Analysis of the Drosophila Response to the Entomopathogenic Nematode Steinernema

    Directory of Open Access Journals (Sweden)

    Shruti Yadav

    2017-06-01

    Full Text Available Drosophila melanogaster is an outstanding model to study the molecular and functional basis of host–pathogen interactions. Currently, our knowledge of microbial infections in D. melanogaster is well understood; however, the response of flies to nematode infections is still in its infancy. Here, we have used the potent parasitic nematode Steinernema carpocapsae, which lives in mutualism with its endosymbiotic bacteria Xenorhabdus nematophila, to examine the transcriptomic basis of the interaction between D. melanogaster and entomopathogenic nematodes. We have employed next-generation RNA sequencing (RNAseq to investigate the transcriptomic profile of D. melanogaster larvae in response to infection by S. carpocapsae symbiotic (carrying X. nematophila or axenic (lacking X. nematophila nematodes. Bioinformatic analyses have identified the strong induction of genes that are associated with the peritrophic membrane and the stress response, as well as several genes that participate in developmental processes. We have also found that genes with different biological functions are enriched in D. melanogaster larvae responding to either symbiotic or axenic nematodes. We further show that while symbiotic nematode infection enriched certain known immune-related genes, axenic nematode infection enriched several genes associated with chitin binding, lipid metabolic functions, and neuroactive ligand receptors. In addition, we have identified genes with a potential role in nematode recognition and genes with potential antinematode activity. Findings from this study will undoubtedly set the stage for the identification of key regulators of antinematode immune mechanisms in D. melanogaster, as well as in other insects of socioeconomic importance.

  14. Prevalence of parasitism and adult survival time of Aedes albifasciatus (Diptera: Culicidae) parasitized by Strelkovimermis spiculatus (Nematoda: Mermithidae).

    Science.gov (United States)

    Di Battista, Cristian M; Fischer, Sylvia; Campos, Raúl E

    2015-12-01

    We described the carryover of Strelkovimermis spiculatus (Poinar and Camino) (Nematoda: Mermithidae) from mosquito larvae, the primary site of maturation, to adults. We analyzed the survival time of male and female Aedes albifasciatus (Macquart) (Diptera: Culicidae) parasitized by S. spiculatus, the time of emergence of nematodes from adult mosquitoes, and the state of parasitism in the same mosquito cohorts during the immature stages. Mosquito larvae with single and multiple parasitism (up to 11 parasites) were observed. The mortality of mosquito larvae and adults was produced in all cases where at least one mermithid emerged. The mortality of S. spiculatus showed an increasing trend in mosquito larvae with larger numbers of nematodes and was higher in larvae parasitized by eight or more nematodes. Maximum survival of parasitized adult females of Ae. albifasciatus was 38 days, while non-parasitized adult males and females survived 39 and 41 days, respectively. Strelkovimermis spiculatus mortality was observed in Ae. albifasciatus larvae with single or multiple parasitisms. The spread of mermithid parasitism in adult mosquito populations is discussed. © 2015 The Society for Vector Ecology.

  15. Origin, distribution and 3D-modeling of Gr-EXPB1, an expansin from the potato cyst nematode Globodera rostochiensis

    NARCIS (Netherlands)

    Kudla, U.; Qin Ling,; Milac, A.; Kielak, A.; Maissen, C.; Overmars, H.A.; Popeijus, H.E.; Roze, E.H.A.; Petrescu, A.J.; Smant, G.; Bakker, J.; Helder, J.

    2005-01-01

    Southern analysis showed that Gr-EXPB1, a functional expansin from the potato cyst nematode Globodera rostochiensis, is member of a multigene family, and EST data suggest expansins to be present in other plant parasitic nematodes as well. Homology modeling predicted that Gr-EXPB1 domain 1 (D1) has a

  16. Apoplastic Venom Allergen-like Proteins of Cyst Nematodes Modulate the Activation of Basal Plant Innate Immunity by Cell Surface Receptors

    NARCIS (Netherlands)

    Lozano Torres, J.L.; Wilbers, R.H.P.; Warmerdam, S.; Finkers-Tomczak, A.M.; Diaz Granados Muñoz, A.; Schaik, van C.C.; Helder, J.; Bakker, J.; Goverse, A.; Schots, A.; Smant, G.

    2014-01-01

    Despite causing considerable damage to host tissue during the onset of parasitism, nematodes establish remarkably persistent infections in both animals and plants. It is thought that an elaborate repertoire of effector proteins in nematode secretions suppresses damage-triggered immune responses of

  17. Co-evolution between Globodera rostochiensis and potato driving sequence diversity of NB-LRR resistance loci and nematode suppressors of plant immunity

    NARCIS (Netherlands)

    Finkers-Tomczak, A.M.

    2011-01-01

    Sedentary plant parasitic nematodes have evolved sophisticated strategies that allow them to transform host cells in the roots of host plants into feeding structures. These complex structures enable the nematodes to complete their life cycle inside a single host plant. Feeding structure initiation

  18. Shifting from priming of salicylic acid- to jasmonic acid-regulated defences by Trichoderma protects tomato against the root knot nematode Meloidogyne incognita

    NARCIS (Netherlands)

    Martínez-Medina, Ainhoa; Fernandez, Ivan; Lok, Gerrit B; Pozo, María J; Pieterse, Corné M J; Van Wees, Saskia C M

    Beneficial root endophytes such as Trichoderma spp. can reduce infections by parasitic nematodes through triggering host defences. Little is currently known about the complex hormone signalling underlying the induction of resistance. In this study, we investigated whether Trichoderma modulates the

  19. Identification and characterisation of a hyper-variable apoplastic effector gene family of the potato cyst nematodes.

    Directory of Open Access Journals (Sweden)

    Sebastian Eves-van den Akker

    2014-09-01

    Full Text Available Sedentary endoparasitic nematodes are obligate biotrophs that modify host root tissues, using a suite of effector proteins to create and maintain a feeding site that is their sole source of nutrition. Using assumptions about the characteristics of genes involved in plant-nematode biotrophic interactions to inform the identification strategy, we provide a description and characterisation of a novel group of hyper-variable extracellular effectors termed HYP, from the potato cyst nematode Globodera pallida. HYP effectors comprise a large gene family, with a modular structure, and have unparalleled diversity between individuals of the same population: no two nematodes tested had the same genetic complement of HYP effectors. Individuals vary in the number, size, and type of effector subfamilies. HYP effectors are expressed throughout the biotrophic stages in large secretory cells associated with the amphids of parasitic stage nematodes as confirmed by in situ hybridisation. The encoded proteins are secreted into the host roots where they are detectable by immunochemistry in the apoplasm, between the anterior end of the nematode and the feeding site. We have identified HYP effectors in three genera of plant parasitic nematodes capable of infecting a broad range of mono- and dicotyledon crop species. In planta RNAi targeted to all members of the effector family causes a reduction in successful parasitism.

  20. Disruption of prefoldin-2 protein synthesis in root-knot nematodes via host-mediated gene silencing efficiently reduces nematode numbers and thus protects plants.

    Science.gov (United States)

    Ajjappala, Hemavathi; Chung, Ha Young; Sim, Joon-Soo; Choi, Inchan; Hahn, Bum-Soo

    2015-03-01

    The aim of this study is to demonstrate the feasibility of down-regulating endogeneous prefoldin-2 root-knot nematode transcripts by expressing dsRNA with sequence identity to the nematode gene in tobacco roots under the influence of strong Arabidopsis ubiquitin (UBQ1) promoter. Root-knot nematodes (RKNs) are sedentary endoparasites infecting a wide range of plant species. They parasitise the root system, thereby disrupting water and nutrient uptake and causing major reductions in crop yields. The most reliable means of controlling RKNs is via the use of soil fumigants such as methyl bromide. With the emergence of RNA interference (RNAi) technology, which permits host-mediated nematode gene silencing, a new strategy to control plant pathogens has become available. In the present study, we investigated host-induced RNAi gene silencing of prefoldin-2 in transgenic Nicotiana benthamiana. Reductions in prefoldin-2 mRNA transcript levels were observed when nematodes were soaked in a dsRNA solution in vitro. Furthermore, nematode reproduction was suppressed in RNAi transgenic lines, as evident by reductions in the numbers of root knots (by 34-60 % in independent RNAi lines) and egg masses (by 33-58 %). Endogenous expression of prefoldin-2, analysed via real-time polymerase chain reaction and Western blotting, revealed that the gene was strongly expressed in the pre-parasitic J2 stage. Our observations demonstrate the relevance and potential importance of targeting the prefoldin gene during the nematode life cycle. The work also suggests that further improvements in silencing efficiency in economically important crops can be accomplished using RNAi directed against plant-parasitic nematodes.

  1. Parasites: Water

    Science.gov (United States)

    ... Tropical Diseases Laboratory Diagnostic Assistance [DPDx] Parasites Home Water Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir Parasites can live in natural water sources. When outdoors, treat your water before drinking ...

  2. Functional C-TERMINALLY ENCODED PEPTIDE (CEP) plant hormone domains evolved de novo in the plant parasite Rotylenchulus reniformis.

    Science.gov (United States)

    Eves-Van Den Akker, Sebastian; Lilley, Catherine J; Yusup, Hazijah B; Jones, John T; Urwin, Peter E

    2016-10-01

    Sedentary plant-parasitic nematodes (PPNs) induce and maintain an intimate relationship with their host, stimulating cells adjacent to root vascular tissue to re-differentiate into unique and metabolically active 'feeding sites'. The interaction between PPNs and their host is mediated by nematode effectors. We describe the discovery of a large and diverse family of effector genes, encoding C-TERMINALLY ENCODED PEPTIDE (CEP) plant hormone mimics (RrCEPs), in the syncytia-forming plant parasite Rotylenchulus reniformis. The particular attributes of RrCEPs distinguish them from all other CEPs, regardless of origin. Together with the distant phylogenetic relationship of R. reniformis to the only other CEP-encoding nematode genus identified to date (Meloidogyne), this suggests that CEPs probably evolved de novo in R. reniformis. We have characterized the first member of this large gene family (RrCEP1), demonstrating its significant up-regulation during the plant-nematode interaction and expression in the effector-producing pharyngeal gland cell. All internal CEP domains of multi-domain RrCEPs are followed by di-basic residues, suggesting a mechanism for cleavage. A synthetic peptide corresponding to RrCEP1 domain 1 is biologically active and capable of up-regulating plant nitrate transporter (AtNRT2.1) expression, whilst simultaneously reducing primary root elongation. When a non-CEP-containing, syncytia-forming PPN species (Heterodera schachtii) infects Arabidopsis in a CEP-rich environment, a smaller feeding site is produced. We hypothesize that CEPs of R. reniformis represent a two-fold adaptation to sustained biotrophy in this species: (i) increasing host nitrate uptake, whilst (ii) limiting the size of the syncytial feeding site produced. © 2016 The Authors. Molecular Plant Pathology Published by British Society for Plant Pathology and John Wiley & Sons Ltd.

  3. How Many Parasites Species a Frog Might Have? Determinants of Parasite Diversity in South American Anurans.

    Directory of Open Access Journals (Sweden)

    Karla Magalhães Campião

    Full Text Available 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.

  4. Nuclear techniqes in the study of genetic resistance to gastrointestinal nematode infections of sheep

    International Nuclear Information System (INIS)

    Dargie, J.D.

    1984-01-01

    The paper reviews genetic resistance of sheep to gastrointestinal nematodes from the standpoint of resistance to the parasites themselves and of resistance to the diseases they produce. Attention is focused on infections with the abomasal parasite Haemonchus contortus and the small intestinal nematode Trichostrongylus colubriformis, and on the role of nuclear techniques both in verifying the existence of genetically based differences in resistance to these parasites and in gaining an understanding of the mechanisms involved. It is concluded that resistance to disease per se is much less important than resistance to parasite establishment and survival and that genetic studies could contribute substantially to the identification of the factors and variables responsible for the present inability to successfully vaccinate young animals against these infections. (author)

  5. Social networks of educated nematodes

    Science.gov (United States)

    Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound...

  6. cyst nematode in tiaret a

    African Journals Online (AJOL)

    F. Labdelli

    1 sept. 2017 ... Syrie par [12], en Arabie saoudite par [16, 17], en Iran par [18] en Inde par [19]en Chine par[20] . .... qui a pour principe d'évaluer le taux de multiplication du nematode en fin de culture et le comparé à ..... cereal cyst nematode complex in relation to breeding resistant durum wheat Fundam. appl. Nemat ...

  7. A lover and a fighter: the genome sequence of an entomopathogenic nematode Heterorhabditis bacteriophora.

    Directory of Open Access Journals (Sweden)

    Xiaodong Bai

    Full Text Available Heterorhabditis bacteriophora are entomopathogenic nematodes that have evolved a mutualism with Photorhabdus luminescens bacteria to function as highly virulent insect pathogens. The nematode provides a safe harbor for intestinal symbionts in soil and delivers the symbiotic bacteria into the insect blood. The symbiont provides virulence and toxins, metabolites essential for nematode reproduction, and antibiotic preservation of the insect cadaver. Approximately half of the 21,250 putative protein coding genes identified in the 77 Mbp high quality draft H. bacteriophora genome sequence were novel proteins of unknown function lacking homologs in Caenorhabditis elegans or any other sequenced organisms. Similarly, 317 of the 603 predicted secreted proteins are novel with unknown function in addition to 19 putative peptidases, 9 peptidase inhibitors and 7 C-type lectins that may function in interactions with insect hosts or bacterial symbionts. The 134 proteins contained mariner transposase domains, of which there are none in C. elegans, suggesting an invasion and expansion of mariner transposons in H. bacteriophora. Fewer Kyoto Encyclopedia of Genes and Genomes Orthologies in almost all metabolic categories were detected in the genome compared with 9 other sequenced nematode genomes, which may reflect dependence on the symbiont or insect host for these functions. The H. bacteriophora genome sequence will greatly facilitate genetics, genomics and evolutionary studies to gain fundamental knowledge of nematode parasitism and mutualism. It also elevates the utility of H. bacteriophora as a bridge species between vertebrate parasitic nematodes and the C. elegans model.

  8. The map-1 gene family in root-knot nematodes, Meloidogyne spp.: a set of taxonomically restricted genes specific to clonal species.

    Directory of Open Access Journals (Sweden)

    Iva Tomalova

    Full Text Available Taxonomically restricted genes (TRGs, i.e., genes that are restricted to a limited subset of phylogenetically related organisms, may be important in adaptation. In parasitic organisms, TRG-encoded proteins are possible determinants of the specificity of host-parasite interactions. In the root-knot nematode (RKN Meloidogyne incognita, the map-1 gene family encodes expansin-like proteins that are secreted into plant tissues during parasitism, thought to act as effectors to promote successful root infection. MAP-1 proteins exhibit a modular architecture, with variable number and arrangement of 58 and 13-aa domains in their central part. Here, we address the evolutionary origins of this gene family using a combination of bioinformatics and molecular biology approaches. Map-1 genes were solely identified in one single member of the phylum Nematoda, i.e., the genus Meloidogyne, and not detected in any other nematode, thus indicating that the map-1 gene family is indeed a TRG family. A phylogenetic analysis of the distribution of map-1 genes in RKNs further showed that these genes are specifically present in species that reproduce by mitotic parthenogenesis, with the exception of M. floridensis, and could not be detected in RKNs reproducing by either meiotic parthenogenesis or amphimixis. These results highlight the divergence between mitotic and meiotic RKN species as a critical transition in the evolutionary history of these parasites. Analysis of the sequence conservation and organization of repeated domains in map-1 genes suggests that gene duplication(s together with domain loss/duplication have contributed to the evolution of the map-1 family, and that some strong selection mechanism may be acting upon these genes to maintain their functional role(s in the specificity of the plant-RKN interactions.

  9. Genomic insights into the origin of parasitism in the emerging plant pathogen Bursaphelenchus xylophilus.

    Directory of Open Access Journals (Sweden)

    Taisei Kikuchi

    2011-09-01

    Full Text Available Bursaphelenchus xylophilus is the nematode responsible for a devastating epidemic of pine wilt disease in Asia and Europe, and represents a recent, independent origin of plant parasitism in nematodes, ecologically and taxonomically distinct from other nematodes for which genomic data is available. As well as being an important pathogen, the B. xylophilus genome thus provides a unique opportunity to study the evolution and mechanism of plant parasitism. Here, we present a high-quality draft genome sequence from an inbred line of B. xylophilus, and use this to investigate the biological basis of its complex ecology which combines fungal feeding, plant parasitic and insect-associated stages. We focus particularly on putative parasitism genes as well as those linked to other key biological processes and demonstrate that B. xylophilus is well endowed with RNA interference effectors, peptidergic neurotransmitters (including the first description of ins genes in a parasite stress response and developmental genes and has a contracted set of chemosensory receptors. B. xylophilus has the largest number of digestive proteases known for any nematode and displays expanded families of lysosome pathway genes, ABC transporters and cytochrome P450 pathway genes. This expansion in digestive and detoxification proteins may reflect the unusual diversity in foods it exploits and environments it encounters during its life cycle. In addition, B. xylophilus possesses a unique complement of plant cell wall modifying proteins acquired by horizontal gene transfer, underscoring the impact of this process on the evolution of plant parasitism by nematodes. Together with the lack of proteins homologous to effectors from other plant parasitic nematodes, this confirms the distinctive molecular basis of plant parasitism in the Bursaphelenchus lineage. The genome sequence of B. xylophilus adds to the diversity of genomic data for nematodes, and will be an important resource in

  10. Genomic Insights into the Origin of Parasitism in the Emerging Plant Pathogen Bursaphelenchus xylophilus

    Science.gov (United States)

    Kikuchi, Taisei; Cotton, James A.; Dalzell, Jonathan J.; Hasegawa, Koichi; Kanzaki, Natsumi; McVeigh, Paul; Takanashi, Takuma; Tsai, Isheng J.; Assefa, Samuel A.; Cock, Peter J. A.; Otto, Thomas Dan; Hunt, Martin; Reid, Adam J.; Sanchez-Flores, Alejandro; Tsuchihara, Kazuko; Yokoi, Toshiro; Larsson, Mattias C.; Miwa, Johji; Maule, Aaron G.; Sahashi, Norio; Jones, John T.; Berriman, Matthew

    2011-01-01

    Bursaphelenchus xylophilus is the nematode responsible for a devastating epidemic of pine wilt disease in Asia and Europe, and represents a recent, independent origin of plant parasitism in nematodes, ecologically and taxonomically distinct from other nematodes for which genomic data is available. As well as being an important pathogen, the B. xylophilus genome thus provides a unique opportunity to study the evolution and mechanism of plant parasitism. Here, we present a high-quality draft genome sequence from an inbred line of B. xylophilus, and use this to investigate the biological basis of its complex ecology which combines fungal feeding, plant parasitic and insect-associated stages. We focus particularly on putative parasitism genes as well as those linked to other key biological processes and demonstrate that B. xylophilus is well endowed with RNA interference effectors, peptidergic neurotransmitters (including the first description of ins genes in a parasite) stress response and developmental genes and has a contracted set of chemosensory receptors. B. xylophilus has the largest number of digestive proteases known for any nematode and displays expanded families of lysosome pathway genes, ABC transporters and cytochrome P450 pathway genes. This expansion in digestive and detoxification proteins may reflect the unusual diversity in foods it exploits and environments it encounters during its life cycle. In addition, B. xylophilus possesses a unique complement of plant cell wall modifying proteins acquired by horizontal gene transfer, underscoring the impact of this process on the evolution of plant parasitism by nematodes. Together with the lack of proteins homologous to effectors from other plant parasitic nematodes, this confirms the distinctive molecular basis of plant parasitism in the Bursaphelenchus lineage. The genome sequence of B. xylophilus adds to the diversity of genomic data for nematodes, and will be an important resource in understanding the

  11. Fast, automated measurement of nematode swimming (thrashing without morphometry

    Directory of Open Access Journals (Sweden)

    Sattelle David B

    2009-07-01

    Full Text Available Abstract Background The "thrashing assay", in which nematodes are placed in liquid and the frequency of lateral swimming ("thrashing" movements estimated, is a well-established method for measuring motility in the genetic model organism Caenorhabditis elegans as well as in parasitic nematodes. It is used as an index of the effects of drugs, chemicals or mutations on motility and has proved useful in identifying mutants affecting behaviour. However, the method is laborious, subject to experimenter error, and therefore does not permit high-throughput applications. Existing automation methods usually involve analysis of worm shape, but this is computationally demanding and error-prone. Here we present a novel, robust and rapid method of automatically counting the thrashing frequency of worms that avoids morphometry but nonetheless gives a direct measure of thrashing frequency. Our method uses principal components analysis to remove the background, followed by computation of a covariance matrix of the remaining image frames from which the interval between statistically-similar frames is estimated. Results We tested the performance of our covariance method in measuring thrashing rates of worms using mutations that affect motility and found that it accurately substituted for laborious, manual measurements over a wide range of thrashing rates. The algorithm used also enabled us to determine a dose-dependent inhibition of thrashing frequency by the anthelmintic drug, levamisole, illustrating the suitability of the system for assaying the effects of drugs and chemicals on motility. Furthermore, the algorithm successfully measured the actions of levamisole on a parasitic nematode, Haemonchus contortus, which undergoes complex contorted shapes whilst swimming, without alterations in the code or of any parameters, indicating that it is applicable to different nematode species, including parasitic nematodes. Our method is capable of analyzing a 30 s movie in

  12. Aging parasites produce offspring with poor fitness prospects.

    Science.gov (United States)

    Lippens, Cédric; Faivre, Bruno; Lechenault, Clothilde; Sorci, Gabriele

    2017-02-01

    Senescing individuals have poor survival prospects and low fecundity. They can also produce offspring with reduced survival and reproductive success. We tested the effect of parental age on the performance of descendants in the nematode Heligmosomoides polygyrus , an intestinal parasite of rodents. We found that offspring of senescing worms had reduced within-host survival and reduced egg shedding over the first month post-infection compared with offspring produced by young parents. These results suggest that declining offspring quality is a component of senescence in parasitic nematodes and might have evolutionary consequences for the optimal schedule of age-dependent investment into reproductive effort. © 2017 The Author(s).

  13. Gastrointestinal nematode control programs with an emphasis on cattle.

    Science.gov (United States)

    Stromberg, Bert E; Gasbarre, Louis C

    2006-11-01

    Control strategies for nematode parasites rely on knowledge of the relationships between the parasites and their hosts. Specifically, these programs are based on identifying crucial points of interaction in the environment provided by the host, including genetics and the immune response, and critical periods in the physical environment in which the eggs and larval stages must develop. When these targets are identified and the interactions understood, cost-effective sustainable programs can be developed using currently available antiparasitic compounds. Resistance to the major classes of anthelmintic compounds requires consideration of new approaches, such as immunity or genetics of the host. Additionally, the efficacy of these compounds can be expanded with combined or concomitant use. Increased study of the use of novel approaches, including fungi, elements such as copper, and plant products, has also occurred. This article explores each of these areas to allow readers to appreciate how various approaches may be developed and incorporated into an effective parasite control program.

  14. Some nematodes of fishes from central China, with the redescription of Procamallanus (Spirocamallanus) fulvidraconis (Camallanidae)

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Nie, P.; Wang, G.

    2003-01-01

    Roč. 50, č. 3 (2003), s. 220-230 ISSN 0015-5683 R&D Projects: GA MŠk ME 424 Grant - others:National Natural Science Foundation of China(CN) 30025035 Institutional research plan: CEZ:AV0Z6022909 Keywords : parasitic nematodes * freshwater fishes * China Subject RIV: EA - Cell Biology Impact factor: 0.469, year: 2003

  15. Analysis and Characterization of Vitamin B Biosynthesis Pathways in the Phytoparasitic Nematode Heterodera Glycines

    Science.gov (United States)

    Craig, James P.

    2009-01-01

    The soybean cyst nematode (SCN), "Heterodera glycines" is an obligate plant parasite that can cause devastating crop losses. To aide in the study of this pathogen, the SCN genome and the transcriptome of second stage juveniles and eggs were shotgun sequenced. A bioinformatic screen of the data revealed nine genes involved in the "de novo"…

  16. New data on the morphology of two nematode species from Caiman crocodilus from Venezuela

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Prouza, A.

    2003-01-01

    Roč. 48, č. 2 (2003), s. 111-118 ISSN 1230-2821 R&D Projects: GA AV ČR IAA6022201 Institutional research plan: CEZ:AV0Z6022909 Keywords : parasitic nematodes * Brevimulticaecum * Micropleura Subject RIV: EA - Cell Biology Impact factor: 0.495, year: 2003

  17. A new atractid nematode, Atractis vidali sp. n. (Nematoda: Atractidae), from cichlid fishes in southern Mexico

    Czech Academy of Sciences Publication Activity Database

    González-Solís, D.; Moravec, František

    2002-01-01

    Roč. 49, č. 3 (2002), s. 227-230 ISSN 0015-5683 R&D Projects: GA AV ČR IAA6022901 Institutional research plan: CEZ:AV0Z6022909 Keywords : parasitic nematode * freshwater fishes * Atractis vidali Subject RIV: EG - Zoology Impact factor: 0.515, year: 2002

  18. Application of kin theory to long-standing problem in nematode production for biocontrol

    Science.gov (United States)

    We present a review of Shapiro-Ilan and Raymond (2016. Limiting opportunities for cheating stabilizes virulence in insect parasitic nematodes. Evolutionary Applications 9:462-470. doi: 10.1111/eva.12348) who tested changes in virulence and reproductive output in a serially propagated entomopathogeni...

  19. Redescription of two species of cystidicolid nematodes (Spirurina: Cystidicolidae) from Notopterus notopterus (Osteichthyes) in Thailand

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Pachanawan, A.; Kamchoo, K.

    2016-01-01

    Roč. 61, č. 2 (2016), s. 278-290 ISSN 1230-2821 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Parasitic nematode * Pseudoproleptus * Spinitectus * morphology * taxonomy * freshwater fish * Oriental Region Subject RIV: EG - Zoology Impact factor: 1.160, year: 2016

  20. Parasitic Meningitis

    Science.gov (United States)

    ... Links Vaccine Schedules Preteen & Teen Vaccines Meningococcal Disease Sepsis ... and Symptoms Diagnosis Treatment Prevention Various parasites can cause meningitis or can affect the brain or nervous ...

  1. Adaptation.

    Science.gov (United States)

    Broom, Donald M

    2006-01-01

    The term adaptation is used in biology in three different ways. It may refer to changes which occur at the cell and organ level, or at the individual level, or at the level of gene action and evolutionary processes. Adaptation by cells, especially nerve cells helps in: communication within the body, the distinguishing of stimuli, the avoidance of overload and the conservation of energy. The time course and complexity of these mechanisms varies. Adaptive characters of organisms, including adaptive behaviours, increase fitness so this adaptation is evolutionary. The major part of this paper concerns adaptation by individuals and its relationships to welfare. In complex animals, feed forward control is widely used. Individuals predict problems and adapt by acting before the environmental effect is substantial. Much of adaptation involves brain control and animals have a set of needs, located in the brain and acting largely via motivational mechanisms, to regulate life. Needs may be for resources but are also for actions and stimuli which are part of the mechanism which has evolved to obtain the resources. Hence pigs do not just need food but need to be able to carry out actions like rooting in earth or manipulating materials which are part of foraging behaviour. The welfare of an individual is its state as regards its attempts to cope with its environment. This state includes various adaptive mechanisms including feelings and those which cope with disease. The part of welfare which is concerned with coping with pathology is health. Disease, which implies some significant effect of pathology, always results in poor welfare. Welfare varies over a range from very good, when adaptation is effective and there are feelings of pleasure or contentment, to very poor. A key point concerning the concept of individual adaptation in relation to welfare is that welfare may be good or poor while adaptation is occurring. Some adaptation is very easy and energetically cheap and

  2. Identification of novel target genes for safer and more specific control of root-knot nematodes from a pan-genome mining.

    Directory of Open Access Journals (Sweden)

    Etienne G J Danchin

    2013-10-01

    Full Text Available Root-knot nematodes are globally the most aggressive and damaging plant-parasitic nematodes. Chemical nematicides have so far constituted the most efficient control measures against these agricultural pests. Because of their toxicity for the environment and danger for human health, these nematicides have now been banned from use. Consequently, new and more specific control means, safe for the environment and human health, are urgently needed to avoid worldwide proliferation of these devastating plant-parasites. Mining the genomes of root-knot nematodes through an evolutionary and comparative genomics approach, we identified and analyzed 15,952 nematode genes conserved in genomes of plant-damaging species but absent from non target genomes of chordates, plants, annelids, insect pollinators and mollusks. Functional annotation of the corresponding proteins revealed a relative abundance of putative transcription factors in this parasite-specific set compared to whole proteomes of root-knot nematodes. This may point to important and specific regulators of genes involved in parasitism. Because these nematodes are known to secrete effector proteins in planta, essential for parasitism, we searched and identified 993 such effector-like proteins absent from non-target species. Aiming at identifying novel targets for the development of future control methods, we biologically tested the effect of inactivation of the corresponding genes through RNA interference. A total of 15 novel effector-like proteins and one putative transcription factor compatible with the design of siRNAs were present as non-redundant genes and had transcriptional support in the model root-knot nematode Meloidogyne incognita. Infestation assays with siRNA-treated M. incognita on tomato plants showed significant and reproducible reduction of the infestation for 12 of the 16 tested genes compared to control nematodes. These 12 novel genes, showing efficient reduction of parasitism when

  3. Uncertain links in host-parasite networks: lessons for parasite transmission in a multi-host system.

    Science.gov (United States)

    Walker, Josephine G; Plein, Michaela; Morgan, Eric R; Vesk, Peter A

    2017-05-05

    For many parasites, the full set of hosts that are susceptible to infection is not known, and this could lead to a bias in estimates of transmission. We used counts of individual adult parasites from historical parasitology studies in southern Africa to map a bipartite network of the nematode parasites of herbivore hosts that occur in Botswana. Bipartite networks are used in community ecology to represent interactions across trophic levels. We used a Bayesian hierarchical model to predict the full set of host-parasite interactions from existing data on parasitic gastrointestinal nematodes of wild and domestic ungulates given assumptions about the distribution of parasite counts within hosts, while accounting for the relative uncertainty of less sampled species. We used network metrics to assess the difference between the observed and predicted networks, and to explore the connections between hosts via their shared parasites using a host-host unipartite network projected from the bipartite network. The model predicts a large number of missing links and identifies red hartebeest, giraffe and steenbok as the hosts that have the most uncertainty in parasite diversity. Further, the unipartite network reveals clusters of herbivores that have a high degree of parasite sharing, and these clusters correspond closely with phylogenetic distance rather than with the wild/domestic boundary. These results provide a basis for predicting the risk of cross-species transmission of nematode parasites in areas where livestock and wildlife share grazing land.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Authors.

  4. Uncertain links in host–parasite networks: lessons for parasite transmission in a multi-host system

    Science.gov (United States)

    2017-01-01

    For many parasites, the full set of hosts that are susceptible to infection is not known, and this could lead to a bias in estimates of transmission. We used counts of individual adult parasites from historical parasitology studies in southern Africa to map a bipartite network of the nematode parasites of herbivore hosts that occur in Botswana. Bipartite networks are used in community ecology to represent interactions across trophic levels. We used a Bayesian hierarchical model to predict the full set of host–parasite interactions from existing data on parasitic gastrointestinal nematodes of wild and domestic ungulates given assumptions about the distribution of parasite counts within hosts, while accounting for the relative uncertainty of less sampled species. We used network metrics to assess the difference between the observed and predicted networks, and to explore the connections between hosts via their shared parasites using a host–host unipartite network projected from the bipartite network. The model predicts a large number of missing links and identifies red hartebeest, giraffe and steenbok as the hosts that have the most uncertainty in parasite diversity. Further, the unipartite network reveals clusters of herbivores that have a high degree of parasite sharing, and these clusters correspond closely with phylogenetic distance rather than with the wild/domestic boundary. These results provide a basis for predicting the risk of cross-species transmission of nematode parasites in areas where livestock and wildlife share grazing land. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289262

  5. Parasitic diseases

    International Nuclear Information System (INIS)

    Rozenshtraukh, L.S.

    1983-01-01

    Foundations of roentgenological semiotics of parasitic diseases of lungs, w hich are of the greatest practical value, are presented. Roentgenological pictu res of the following parasitic diseases: hydatid and alveolar echinococcosis, pa ragonimiasis, toxoplasmosis, ascariasis, amebiasis, bilharziasis (Schistosomias is) of lungs, are considered

  6. Fish parasites

    DEFF Research Database (Denmark)

    This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems......This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems...

  7. Helminths parasitizing larval fish from Pantanal, Brazil.

    Science.gov (United States)

    Lacerda, A C F; Santin, M; Takemoto, R M; Pavanelli, G C; Bialetzki, A; Tavernari, F C

    2009-03-01

    Fish larvae of 'corvinas' (Pachyurus bonariensis and Plagioscion ternetzi) from Sinhá Mariana Lagoon, Mato Grosso State, were collected from March 2000 to March 2004, in order to determine the parasitic fauna of fishes. Larvae from the two species were parasitized by the same endoparasites: Contracaecum sp. Type 2 (larvae) (Nematoda: Anisakidae) in the mesentery and Neoechinorhynchus (Neoechinorhynchus) paraguayensis (Acanthocephala: Neoechinorhynchidae) in the stomach and the terminal portion of the intestine. Statistical analysis showed that there was a significant positive correlation between the standard length of hosts and the abundance of acanthocephalans and nematodes, and that the prevalence of nematodes presented a significant positive correlation with the standard length of the two species of hosts, indicating the presence of a cumulative process of infection. The present study constitutes the first record of nematodes and acanthocephalans parasitizing larval fish, as well as the first record of endoparasites in fish larvae in Brazil. In addition, it lists a new locality and two species of hosts for Contracaecum sp. Type 2 (larva) and N. (N.) paraguayensis.

  8. IDENTIFIKASI NEMATODA PARASIT PADA SALURAN PENCERNAAN MARMUT (Cavia cobaya SEBAGAI SUMBER BELAJAR BIOLOGI PADA MATERI INVERTEBRATA

    Directory of Open Access Journals (Sweden)

    Septia Nurhasanah

    2014-05-01

    Full Text Available The research was conducted in the Laboratory of Science Education, University of Muhammadiyah Metro. The research is a descriptive analysis, morphological observations were made by identifying the nematode parasite found that Trichostrongylus sp, Strongyloides sp, Trichuris sp, Trichuris sp. The results showed the prevalence and intensity values is the large number of guinea pigs to parasites divided by the number of guinea pigs that are 100% inspected. While the intensity is seen from the total number of nematode parasites that infect in the number of guinea pigs infected with a parasite that is 2,3. The population in this study was 10 cows pigs (Cavia cobaya . This study took a part in the digestion of marmots (Cavia cobaya the intestines and stomach , then cut and taken part in the large intestine and be Indian ink or coloring 2-3 drops to be easily identified microscopically . Put the preparations into a petri dish , and given alcohol as much as 96 % with 2-3 drops . Taking part in the examination of the large intestine to taste then used the nematode worm structure with Indian ink dye to be observed , and placed in the glass object . Observed with a microscope. Document if the parasites are found by using the camera Erlina 2008. Identification of the observations made have found 3 types of parasites that attack the guinea pig (Cavia cobaya is Strongyloides sp on samples 1,2,3,4,5,6 , dan10 . Then parasite Trichuris sp species found in samples 8 and 9. Trichostrongylus sp parasite species found in sample 7 . Parasitic nematodes found were 3 types of Trichostrongylus sp, Strongyloides sp, Trichuris sp. Number of samples that have been observed as many as 10 cows pigs (Cavia cobaya , with the overall result is as much as 23 tails parasites.               Kata kunci: nematode parasit, marmut (Cavia cobaya, sumber belajar biologi.

  9. Expansion of Ashworthius sidemi in red deer and roe deer from the Lower Silesian Wilderness and its impact on infection with other gastrointestinal nematodes.

    Science.gov (United States)

    Demiaszkiewicz, Aleksander W; Merta, Dorota; Kobielski, Janusz; Filip, Katarzyna J; Pyziel, Anna M

    2017-12-20

    Nematodes Ashworthius sidemi are typical parasites of Asiatic cervids, mostly sika deer (Cervus nippon). Migrating red deer have probably introduced this parasite to the area of Poland from neighbouring countries. The aim of the study was to determine prevalence and intensity of infection of red deer and roe deer from the Lower Silesian Wilderness with A. sidemi after one year from previous studies and to examine the influence of these parasites on other species of gastrointestinal nematodes. 31 abomasa of red deer and 3 abomasa of roe deer from Forest Dictrict of Ruszów have been examined on the presence of parasites. In comparison with previous studies, red deer showed significant, over triple increase of prevalence of A. sidemi and over fivefold increase of mean intensity of infection. Maximum intensity of infection has increased over 24 times. These results indicate on dynamic spread of this new aswortiosis foci. Apart from previously registered parasite species, four new nematodes have been found in examined red deer and roe deer during this year studies. Red deer have been infected with Spiculopteragia assymmetrica, typical for fallow deer and Haemonchus placei - typical for bovine, whereas roe deer have been infected with Trichostrongylus axei and Trichostrongylus capricola, parasites of sheep, goats and bovine. Prevalence of red deer infection with nematodes S. boehmi and Ostertagia leptospicularis was lower than two years ago while prevalence of infection with S. mathevossiani and O. kolchida was higher. Intensity of infection with these nematodes has increased.

  10. Epidemiology, sero-diagnosis and therapeutic studies on nematodes infection in balochi range-sheep at district quetta, balochistan, pakistan.

    Directory of Open Access Journals (Sweden)

    Abdul Razzaq

    2014-06-01

    Full Text Available Among the infectious organisms of parasitic origin, gastrointestinal nematodes are very important as they have been reported worldwide. The main aim of the present research study to highlight the annual epidemiological contributing factors associated with the prevalence of gastrointestinal nematodes and their control in sheep.A total 1200 faecal samples (100 per month were collected from farmers holding Balochi-sheep (either sexes, 1-5 years old during January-December 2012 and analyzed to determine the prevalence of nematodes based on microscopy and ELISA based diagnostic assay. Therapeutic efficacies of different synthetic and herbal medicines against these nematodes were assessed by field trials.Results showed that 23.92% Balochi-sheep were infected with nematodes. Five nematodes infections were recorded with highest prevalence of Haemonchus (7.75% followed by Nematodirus (7.58%, Strongyloides (4.42%, Trichostrongylus (2.33% and Trichuris (1.83%. The younger and older ewes (one and five years presented higher nematodes prevalence with peak during March/April and August/September. Haemonchus and Trichuris positive samples based on coprological examination were also showed 92-100% positive sensitivity for these nematodes by the ELISA. Sheep treated with Ivermectin showed higher reduction (97.76% in nematode egg counts followed by Atreefal deedan (96.42% and Oxfendazole (95.44%, respectively.The gastro-intestinal nematodes are prevalent in all age and either sex of Balochi-sheep with peak during summer. The ELISA based diagnosis is more accurte. The synthetic and herbal products are very effective against sheep nematodes.

  11. A Large Collection of Novel Nematode-Infecting Microsporidia and Their Diverse Interactions with Caenorhabditis elegans and Other Related Nematodes

    Science.gov (United States)

    Zhang, Gaotian; Sachse, Martin; Prevost, Marie-Christine; Troemel, Emily R.; Félix, Marie-Anne

    2016-01-01

    microsporidian infections in nematodes, and provide a rich resource to investigate host-parasite coevolution in tractable nematode hosts. PMID:27942022

  12. Expression of Arabidopsis genes AtNPR1 and AtTGA2 in transgenic soybean roots of composite plants confers resistance to root-knot nematode (Meloidogyne incognita)

    Science.gov (United States)

    Root-knot nematodes (RKN; Meloidogyne spp.) are among the most destructive of the plant parasitic nematodes, infecting almost all cultivated plants and resulting in yield losses of billions of dollars annually. NPR1 (nonexpresser of pathogenesis related genes 1, AtNPR1) plays a positive role in the ...

  13. Host-Parasite Relationship Between African Yam Bean ...

    African Journals Online (AJOL)

    Host-Parasite Relationship Between African Yam Bean, Sphenostylis stenocarpa (Hochst. ... Plant Products Research Journal ... Inoculated plants in the pots received 4,000 eggs of M. incognita while the field was confirmed to be infested with inoculum level of about 75 nematode larvae per 50 cm3 of soil sample. Results ...

  14. Prevalence of gastrointestinal parasites of cattle in Abeokuta, Ogun ...

    African Journals Online (AJOL)

    Analysis revealed significant (p<0.05) difference between the prevalence of nematodes and trematode as well as the mean faecal egg count of the cattle sampled in the abattoir and the University farm. In conclusion, gastrointestinal parasites are prevalent in cattle in the study area with Eimeria spp being most prevalent.

  15. Baboons as potential reservoirs of zoonotic gastrointestinal parasite ...

    African Journals Online (AJOL)

    EB

    contaminated food, water and hands10. They are known to be the most common causative agents of debilitating diarrhoea in humans. However, it should be noted that although baboons at YNP showed natural infections with eggs and cysts of helminth, nematode and protozoan parasites that are morphologically similar to ...

  16. Gastro-Intestinal Parasites of Warthogs (Phacochoerus Africanus ...

    African Journals Online (AJOL)

    A survey was conducted to assess the prevalence of gastrointestinal parasites in warthogs from the Nazinga Game Ranch of Burkina Faso. The study revealed that Eight different nematodes and one estode species were present in the gastrointestinal tracks of the animals. In the stomach, Simondsia paradoxa was found at ...

  17. Prevalence of Gastro-intestinal Parasites of Cattle in Ogbomoso ...

    African Journals Online (AJOL)

    A study was carried out on the prevalence of gastrointestinal (GI) nematodes infection in naturally infected cattle in Ogbomoso area of Oyo State using standard parasitological techniques. The results indicated that out of the 1000 cattle examined, 30(3%) were infected and parasites identified were Haemonchus contortus ...

  18. Comparison of parasitic helminth infection between the different age ...

    African Journals Online (AJOL)

    They were subjected to parasitological examinations. two cestode types - Amonotaenia sp and Polyonchobothrium clarias; two nematode types - Paracamallanus sp and Procamallanus laevionchus and one acanthocephalan – Neoechinorhynchus rutili were detected. Eighty-eight parasites were recovered. 27.5% of all fish ...

  19. Parasites of Satanoperca jurupari (Osteichthyes: Cichlidae) from Brazil.

    Science.gov (United States)

    Melo, Marly de Fátima Carvalho de; Dos Santos, Everton Gustavo Nunes; Giese, Elane Guerreiro; Dos Santos, Jeannie Nascimento; Santos, Cláudia Portes

    2012-01-01

    Satanoperca jurupari (Osteichthyes: Cichlidae) is reported for the first time to be parasitized by the nematodes Procamallanus (Spirocamallanus) rarus Travassos, Artigas and Pereira, 1928, Procamallanus (Spirocamallanus) sp., larvae of Raphidascaroides sp. and Anisakidae gen. sp., and by the acanthocephalan Neoechinorhynchus (Neoechinorhynchus) paraguayensis Machado Filho (Rev Bras Biol 19:379-381, 1959).

  20. Evaluation of Low-Input Management Methods for Plant Parasitic ...

    African Journals Online (AJOL)

    Field trial was conducted at the National Horticultural Research Institute's experimental field between July 2003 and January 2005 to determine the effect of some cultural practices on the populations and control of plant parasitic nematodes infestation and their effect on some growth and yield attributes of plantain cv.

  1. Parasites of Periplaneta americana linnaeus "domestic cockroach" from Ica.

    Directory of Open Access Journals (Sweden)

    Mary Fernádez B.

    2014-06-01

    Full Text Available 244 specimens of Periplaneta americana Linnaeus from 13 localities of Ica were studied. Nematodes and protozoa were identified. They are Lophomonas blattarum, Leptomonas sp., Leidynema appendiculatum and Hammerschmidtiella diesingi. Also, parasites of man were found, three of which are pathogenic: Giardia lamblia, Blastocystis hominis and Cryptosporidium sp.

  2. Adaptation

    International Development Research Centre (IDRC) Digital Library (Canada)

    . Dar es Salaam. Durban. Bloemfontein. Antananarivo. Cape Town. Ifrane ... program strategy. A number of CCAA-supported projects have relevance to other important adaptation-related themes such as disaster preparedness and climate.

  3. Seasonal distribution of gastrointestinal nematode infections in sheep in a semiarid region, northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Maria de Fátima de Souza

    Full Text Available The objective of this study was to determine the seasonal distribution and gastrointestinal nematode parasite load in crossbred Santa Inês tracer lambs, and to correlate the rainfall during the study period with occurrences of parasitic infections. Sixty-four male tracer lambs between the ages of four and eight months were used in the study. Two tracer lambs were inserted into the herd every 28 days to determine the pattern of infective larvae available in the environment. Variation in the fecal egg count (FEC of nematodes was observed at the study site, with many samples containing undetectable parasite loads during the dry season. The larvae identified in coprocultures wereHaemonchus sp., Trichostrongylus sp.,Cooperia sp., Strongyloides sp. andOesophagostomum sp. The nematodes recovered at necropsy were Haemonchus contortus, Trichostrongylus colubriformis, Cooperia punctata, C. pectinata, Trichuris sp.,Oesophagostomum sp. and Skrajabinema ovis. The total number of larvae and the total number of immature and adult forms recovered from the tracers showed seasonal distributions that significantly correlated with the amount of rainfall received that month (p value ≅ 0.000 in all cases . The species H. contortus was predominant in the herd and should be considered to be main pathogenic nematode species in these hosts under these conditions.

  4. FLP-1 neuropeptides modulate sensory and motor circuits in the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Buntschuh, Ingrid; Raps, Daniel A; Joseph, Ivor; Reid, Christopher; Chait, Alexander; Totanes, Raubern; Sawh, Michelle; Li, Chris

    2018-01-01

    Parasitic nematodes infect over one quarter of the population worldwide, causing morbidity in over one billion people. Current anthelmintic drugs are beginning to lose effectiveness due to the presence of resistant strains. We are interested in the role of neuropeptides, which regulate behaviors in all organisms, as another possible target for anthelmintic drugs. FMRFamide-related peptides (FaRPs) are a family of neuropeptides that are conserved throughout the animal kingdom. In particular, nematodes contain the largest family of FaRPs identified thus far and many of these FaRPs are identical among different nematode species; FaRPs in nematodes are collectively referred to as FLPs (FMRFamide-like peptides). However, little is known about the function of these FLPs. We are using the non-parasitic nematode Caenorhabditis elegans as a model for examining FLPs in nematodes. C. elegans contains at least 31 flp genes that encode 72 potential FLPs. Among the flp genes, flp-1 is one of the few that is universally found in nematodes. FLP-1 neuropeptides were previously reported to be involved in sensory and motor functions. However, previous alleles of flp-1 also disrupted a neighboring gene, daf-10. To understand the phenotypes of flp-1, new alleles that specifically disrupt flp-1 were characterized. The previously reported locomotory and egg-laying defects were found to be due to loss of flp-1, while the osmolarity defect is due to loss of daf-10. In addition, loss of flp-1 and daf-10 both cause several phenotypes that increase in severity in the double mutants by disrupting different neurons in the neural circuits.

  5. Influence of industrial heavy metal pollution on soil free-living nematode population

    International Nuclear Information System (INIS)

    Pen-Mouratov, Stanislav; Shukurov, Nosir; Steinberger, Yosef

    2008-01-01

    The effect of distance from a heavy metal pollution source on the soil nematode community (trophic structure, sex structure, and taxa composition) was investigated along a 15-km transect originating at the Almalyk Industrial Complex, Uzbekistan (pollution source). The soil nematode community was exposed to heavy metal influence both directly and through soil properties changes. Pollution effect on the density and biomass of soil free-living nematodes was found to be highest at pollution source, with fungivores and plant parasites dominating at the upper and deeper soil layers next to the pollution source. These groups decreased along the transect, yielding domination to bacteria- and fungi-feeders. The sex ratio of nematode communities was found to be dependent on heavy metal pollution levels, with the juveniles being the most sensitive nematode group. The Maturity and modified Maturity Indices, reflecting the degree of disturbance of the soil ecosystem, were found to be the most sensitive indices. - Trophic structure and sex ratio of soil nematode population are sensitive tools for monitoring industrial pollution

  6. Comparative Genomics and Transcriptomics Analyses Reveal Divergent Lifestyle Features of Nematode Endoparasitic Fungus Hirsutella minnesotensis

    Science.gov (United States)

    Lai, Yiling; Liu, Keke; Zhang, Xinyu; Zhang, Xiaoling; Li, Kuan; Wang, Niuniu; Shu, Chi; Wu, Yunpeng; Wang, Chengshu; Bushley, Kathryn E.; Xiang, Meichun; Liu, Xingzhong

    2014-01-01

    Hirsutella minnesotensis [Ophiocordycipitaceae (Hypocreales, Ascomycota)] is a dominant endoparasitic fungus by using conidia that adhere to and penetrate the secondary stage juveniles of soybean cyst nematode. Its genome was de novo sequenced and compared with five entomopathogenic fungi in the Hypocreales and three nematode-trapping fungi in the Orbiliales (Ascomycota). The genome of H. minnesotensis is 51.4 Mb and encodes 12,702 genes enriched with transposable elements up to 32%. Phylogenomic analysis revealed that H. minnesotensis was diverged from entomopathogenic fungi in Hypocreales. Genome of H. minnesotensis is similar to those of entomopathogenic fungi to have fewer genes encoding lectins for adhesion and glycoside hydrolases for cellulose degradation, but is different from those of nematode-trapping fungi to possess more genes for protein degradation, signal transduction, and secondary metabolism. Those results indicate that H. minnesotensis has evolved different mechanism for nematode endoparasitism compared with nematode-trapping fungi. Transcriptomics analyses for the time-scale parasitism revealed the upregulations of lectins, secreted proteases and the genes for biosynthesis of secondary metabolites that could be putatively involved in host surface adhesion, cuticle degradation, and host manipulation. Genome and transcriptome analyses provided comprehensive understanding of the evolution and lifestyle of nematode endoparasitism. PMID:25359922

  7. Study of Enhanced Radiation Impact on the Resistance of Plant - Parasite System

    International Nuclear Information System (INIS)

    Damianova, A.; Sivriev, I.; Baicheva, O.; Ivanova, I

    2004-01-01

    The paper aimed to report the results from the experiments carried out in order to investigate the dependence between the increasing radiation doses and the vitality and reproductivity of the wide spread in the natural and agroecosystems nematodes Meloidogyne arenaria used as a laboratory model. In this study the influence of different doses of α- and γ- radiation have been examined using isotopes of 241 Am and 60 Co. As a result of the performed experiments a conclusion could be made for the protective role of the glycoproteid structures of the parasite sac against α-radiation. Part of the effects observed probably are due to the development in the process of evolution of a protective mechanism in order to adapt the organisms to the modifying of the radiation background

  8. Limiting opportunities for cheating stabilizes virulence in insect parasitic nematodes

    Science.gov (United States)

    Cooperative secretion of virulence factors by pathogens can often lead to social conflict as cheating mutants that benefit from collective action, but do not contribute to it, can arise and locally outcompete cooperators within hosts, leading to loss of virulence. There is a wide range of in vivo st...

  9. occurrence of plant parasitic nematodes and factors that enhance

    African Journals Online (AJOL)

    Administrator

    investment and impacts in developing countries1991-1992. CIMMYT Mexico. CIMMYT (International Maize and Wheat. Improvement Center), 1992. CIMMYT world maize facts and trends: maize research investment and impacts in developing countries1991-1992. CIMMYT Mexico. Coyne, D. L. and Talwana, L. A. H. 2000.

  10. Prevalence and burden of gastrointestinal parasites of Djallonke sheep in Ayeduase, Kumasi, Ghana

    Directory of Open Access Journals (Sweden)

    Moses Owusu

    2016-04-01

    Full Text Available Aim: This study was conducted to determine the prevalence and burden of gastrointestinal (GIT parasites of Djallonke sheep in Ayeduase, Kumasi from January 2015 to July 2015. Materials and Methods: The presence of nematodal eggs and coccidial oocysts in fecal samples were analyzed using the saturated sodium chloride floatation technique. Identification of eggs or oocysts was done on the basis of morphology and size of the eggs or oocysts. Results: Out of 110 fecal samples of sheep examined, 108 were infected with GIT parasites, representing a prevalence rate of 98.2%. The total infection rate of GIT nematodes and coccidia oocysts were 94.5% and 51.8%, respectively. Strongyle nematode (94.5% was the most prevalent GIT nematode detected, followed by strongyloides (27.3%. The average nematodal burden in g/feces was significantly higher (p0.05 from each other. The average coccidia oocysts count in g/feces was significantly higher (p0.05 in the coccidia oocysts count of rams under 1 year, gimmers, ewes, and rams over 1 year. From the studied animals, 40%, 6.36%, 48.18%, and 5.45% had heavy, moderate, light, and no infestation, respectively, with GIT nematodes. Conclusion: Djallonke sheep in Ayeduase, Kumasi, were infested with varying amounts of GIT parasites. The infestation of Djallonke sheep by GIT parasites also varies among different age groups and sexes.

  11. Not to be suppressed? Rethinking the host response at a root-parasite interface.

    Science.gov (United States)

    Goto, Derek B; Miyazawa, Hikota; Mar, Jessica C; Sato, Masanao

    2013-12-01

    Root-knot nematodes are highly efficient plant parasites that establish permanent feeding sites within host roots. The initiation of this feeding site is critical for parasitic success and requires an interaction with multiple signaling pathways involved in plant development and environmental response. Resistance against root-knot nematodes is relatively rare amongst their broad host range and they remain a major threat to agriculture. The development of effective and sustainable control strategies depends on understanding how host signaling pathways are manipulated during invasion of susceptible hosts. It is generally understood that root-knot nematodes either suppress host defense signaling during infestation or are able to avoid detection altogether, explaining their profound success as parasites. However, when compared to the depth of knowledge from other well-studied pathogen interactions, the published data on host responses to root-knot nematode infestation do not yet provide convincing support for this hypothesis and alternative explanations also exist. It is equally possible that defense-like signaling responses are actually induced and required during the early stages of root-knot nematode infestation. We describe how defense-signaling is highly context-dependent and that caution is necessary when interpreting transcriptional responses in the absence of appropriate control data or stringent validation of gene annotation. Further hypothesis-driven studies on host defense-like responses are required to account for these limitations and advance our understanding of root-knot nematode parasitism of plants. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Experimental Evolution withCaenorhabditisNematodes.

    Science.gov (United States)

    Teotónio, Henrique; Estes, Suzanne; Phillips, Patrick C; Baer, Charles F

    2017-06-01

    The hermaphroditic nematode Caenorhabditis elegans has been one of the primary model systems in biology since the 1970s, but only within the last two decades has this nematode also become a useful model for experimental evolution. Here, we outline the goals and major foci of experimental evolution with C. elegans and related species, such as C . briggsae and C. remanei , by discussing the principles of experimental design, and highlighting the strengths and limitations of Caenorhabditis as model systems. We then review three exemplars of Caenorhabditis experimental evolution studies, underlining representative evolution experiments that have addressed the: (1) maintenance of genetic variation; (2) role of natural selection during transitions from outcrossing to selfing, as well as the maintenance of mixed breeding modes during evolution; and (3) evolution of phenotypic plasticity and its role in adaptation to variable environments, including host-pathogen coevolution. We conclude by suggesting some future directions for which experimental evolution with Caenorhabditis would be particularly informative. Copyright © 2017 Teotónio et al.

  13. Do the morphological and functional traits of free-living marine nematodes mirror taxonomical diversity?

    Science.gov (United States)

    Semprucci, F; Cesaroni, L; Guidi, L; Balsamo, M

    2018-04-01

    The taxonomical structure and diversity of nematode assemblages are the main attributes analyzed in ecology, but nematode adaptations to their habitats are still understudied. Accordingly, a survey on some known and other newly proposed morpho-functional traits was carried out in order to: determine if the morpho-functional diversity of nematodes mirrors their taxonomical diversity; and assess potential nematode adaptations to sediment type and hydrodynamic stress. Morpho-functional traits were investigated both singularly and together and showed significant differences related to these environmental factors. The greatest taxonomical and morpho-functional diversity was found in medium-coarse sand (M-CS) and at an intermedium energy level (IEL). The M-CS and IEL were probably richer in micro-habitats and subject to a low selective pressure, hosting nematodes with a wide range of adaptations. The mirroring of morpho-functional diversity with taxonomical diversity is crucial for the future growth of the use of nematodes in biomonitoring. This is because the study of their morpho-functional traits could reduce the level of work involved and the costs of any analyses. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Adapt

    Science.gov (United States)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  15. Parasite-induced fruit mimicry in a tropical canopy ant.

    Science.gov (United States)

    Yanoviak, S P; Kaspari, M; Dudley, R; Poinar, G

    2008-04-01

    Some parasites modify characteristics of intermediate hosts to facilitate their consumption by subsequent hosts, but examples of parasite-mediated mimicry are rare. Here we report dramatic changes in the appearance and behavior of nematode-parasitized ants such that they resemble ripe fruits in the tropical rain forest canopy. Unlike healthy ants, which are completely black, infected ants have bright red, berry-like gasters full of parasite eggs. The infected gasters are held in a conspicuous elevated position as the ants are walking, and they are easily detached from living ants, which also exhibit reduced defensive responses. This combination of changes presumably makes the infected ants attractive to frugivorous birds, which ingest the red gasters and pass the parasite eggs in their feces. The feces are collected by ants and fed to the developing brood, thus completing the cycle. This is the first documentation of parasites causing apparent fruit mimicry in an animal host to complete their life cycle.

  16. Anti-parasitic activity of pelleted sainfoin (Onobrychis viciifolia) against Ostertagia ostertagi and Cooperia oncophora in calves.

    Science.gov (United States)

    Desrues, Olivier; Peña-Espinoza, Miguel; Hansen, Tina V A; Enemark, Heidi L; Thamsborg, Stig M

    2016-06-10

    Increasing anthelmintic-resistance in nematodes of ruminants emphasises the need for sustainable parasite control. Condensed tannin-containing legume forages such as sainfoin (Onobrychis viciifolia) have shown promising anthelmintic properties in small ruminants but this has never been explored in cattle. Therefore, our aim was to examine the efficacy of sainfoin against cattle nematodes in vivo. Fifteen Jersey male calves (2-4 month-old) were allocated into two groups and fed isoproteic and isoenergetic diets mainly composed of sainfoin pellets (Group SF; n = 9, three pens) or concentrate and grass-clover hay (Group CO; n = 6, two pens). After 16 days of adaptation, all animals were experimentally infected with 10,000 and 66,000 third-stage larvae of Ostertagia ostertagi and Cooperia oncophora, respectively. Egg excretion, blood parameters and bodyweights were recorded throughout the study. Worms were harvested by sieving for quantification and scanning electron microscopy (SEM) 42 days post-infection (dpi) when the calves were necropsied. The number of O. ostertagi adults in the abomasum was reduced by 50 % in Group SF compared with Group CO (P  0.05). Likewise, no statistical difference in total worm burdens of C. oncophora was found between the groups. Weight gains were lower for Group SF (P < 0.05), which may reflect lower digestibility and phosphorus levels in the SF diet, despite similar feed intake at pen-level. Overall, the effect of sainfoin on abomasal nematodes corroborates results from studies with small ruminants and encourages further investigations of the use of this crop for control of cattle nematodes.

  17. Mind the gaps in research on the control of gastrointestinal nematodes of farmed ruminants and pigs.

    Science.gov (United States)

    Charlier, J; Thamsborg, S M; Bartley, D J; Skuce, P J; Kenyon, F; Geurden, T; Hoste, H; Williams, A R; Sotiraki, S; Höglund, J; Chartier, C; Geldhof, P; van Dijk, J; Rinaldi, L; Morgan, E R; von Samson-Himmelstjerna, G; Vercruysse, J; Claerebout, E

    2017-11-10

    Gastrointestinal (GI) nematode control has an important role to play in increasing livestock production from a limited natural resource base and to improve animal health and welfare. In this synthetic review, we identify key research priorities for GI nematode control in farmed ruminants and pigs, to support the development of roadmaps and strategic research agendas by governments, industry and policymakers. These priorities were derived from the DISCONTOOLS gap analysis for nematodes and follow-up discussions within the recently formed Livestock Helminth Research Alliance (LiHRA). In the face of ongoing spread of anthelmintic resistance (AR), we are increasingly faced with a failure of existing control methods against GI nematodes. Effective vaccines against GI nematodes are generally not available, and anthelmintic treatment will therefore remain a cornerstone for their effective control. At the same time, consumers and producers are increasingly concerned with environmental issues associated with chemical parasite control. To address current challenges in GI nematode control, it is crucial to deepen our insights into diverse aspects of epidemiology, AR, host immune mechanisms and the socio-psychological aspects of nematode control. This will enhance the development, and subsequent uptake, of the new diagnostics, vaccines, pharma-/nutraceuticals, control methods and decision support tools required to respond to the spread of AR and the shifting epidemiology of GI nematodes in response to climatic, land-use and farm husbandry changes. More emphasis needs to be placed on the upfront evaluation of the economic value of these innovations as well as the socio-psychological aspects to prioritize research and facilitate uptake of innovations in practice. Finally, targeted regulatory guidance is needed to create an innovation-supportive environment for industries and to accelerate the access to market of new control tools. © 2017 Blackwell Verlag GmbH.

  18. Geography and host biogeography matter for understanding the phylogeography of a parasite.

    OpenAIRE

    Nieberding, Caroline M.; Durette-Desset, Marie-Claude; Vanderpoorten, Alain; Casanova, J. C.; Ribas, A.; Deffontaine, V.; Feliu, C.; Morand, S.; Libois, Roland; Michaux, Johan

    2008-01-01

    The co-evolution between hosts and parasites has long been recognized as a fundamental driver of macro-evolutionary patterns of diversification. The effect of co-differentiation on parasite diversification is, however, often confounded by underlying geographic patterns of host distribution. In order to disentangle the confounding effects of allopatric versus host speciation, the mitochondrial cytochrome b (cyt b) gene was sequenced in seventy individuals of the parasitic nematode genus Heligm...

  19. Parasite prevalence in Bagrus fiamentosus and Citharinus citharus from lower River Benue, Makurdi

    OpenAIRE

    Shola Gabriel Solomon; Victor Tosin Okomoda; Victoria Makeri

    2016-01-01

    Objective: To determine the parasite prevalence in Bagrus filamentosus (B. filamentosus) and Citharinus citharus (C. citharus) from lower River Benue in Makurdi. Methods: A total of 100 specimens each of both B. filamentosus and C. citharus were collected from River Benue, Makurdi, Nigeria and were examined for parasites after measuring basic morphometric parameters. Results: A total of 198 parasitic organisms comprising Eustrongylides africanus (nematode), Diphyllobothrium ...

  20. Adaptation

    International Development Research Centre (IDRC) Digital Library (Canada)

    Nairobi, Kenya. 28 Adapting Fishing Policy to Climate Change with the Aid of Scientific and Endogenous Knowledge. Cap Verde, Gambia,. Guinea, Guinea Bissau,. Mauritania and Senegal. Environment and Development in the Third World. (ENDA-TM). Dakar, Senegal. 29 Integrating Indigenous Knowledge in Climate Risk ...