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Sample records for parasitic nematode brugia

  1. Heme acquisition in the parasitic filarial nematode Brugia malayi

    PubMed Central

    Luck, Ashley N.; Yuan, Xiaojing; Voronin, Denis; Slatko, Barton E.; Hamza, Iqbal; Foster, Jeremy M.

    2016-01-01

    Nematodes lack a heme biosynthetic pathway and must acquire heme from exogenous sources. Given the indispensable role of heme, this auxotrophy may be exploited to develop drugs that interfere with heme uptake in parasites. Although multiple heme-responsive genes (HRGs) have been characterized within the free-living nematode Caenorhabditis elegans, we have undertaken the first study of heme transport in Brugia malayi, a causative agent of lymphatic filariasis. Through functional assays in yeast, as well as heme analog, RNAi, and transcriptomic experiments, we have shown that the heme transporter B. malayi HRG-1 (BmHRG-1) is indeed functional in B. malayi. In addition, BmHRG-1 localizes both to the endocytic compartments and cell membrane when expressed in yeast cells. Transcriptomic sequencing revealed that BmHRG-1, BmHRG-2, and BmMRP-5 (all orthologs of HRGs in C. elegans) are down-regulated in heme-treated B. malayi, as compared to non–heme-treated control worms. Likely because of short gene lengths, multiple exons, other HRGs in B. malayi (BmHRG-3–6) remain unidentified. Although the precise mechanisms of heme homeostasis in a nematode with the ability to acquire heme remains unknown, this study clearly demonstrates that the filarial nematode B. malayi is capable of transporting exogenous heme.—Luck, A. N., Yuan, X., Voronin, D., Slatko, B. E., Hamza, I., Foster, J. M. Heme acquisition in the parasitic filarial nematode Brugia malayi. PMID:27363426

  2. Draft genome of the filarial nematode parasite Brugia malayi.

    PubMed

    Ghedin, Elodie; Wang, Shiliang; Spiro, David; Caler, Elisabet; Zhao, Qi; Crabtree, Jonathan; Allen, Jonathan E; Delcher, Arthur L; Guiliano, David B; Miranda-Saavedra, Diego; Angiuoli, Samuel V; Creasy, Todd; Amedeo, Paolo; Haas, Brian; El-Sayed, Najib M; Wortman, Jennifer R; Feldblyum, Tamara; Tallon, Luke; Schatz, Michael; Shumway, Martin; Koo, Hean; Salzberg, Steven L; Schobel, Seth; Pertea, Mihaela; Pop, Mihai; White, Owen; Barton, Geoffrey J; Carlow, Clotilde K S; Crawford, Michael J; Daub, Jennifer; Dimmic, Matthew W; Estes, Chris F; Foster, Jeremy M; Ganatra, Mehul; Gregory, William F; Johnson, Nicholas M; Jin, Jinming; Komuniecki, Richard; Korf, Ian; Kumar, Sanjay; Laney, Sandra; Li, Ben-Wen; Li, Wen; Lindblom, Tim H; Lustigman, Sara; Ma, Dong; Maina, Claude V; Martin, David M A; McCarter, James P; McReynolds, Larry; Mitreva, Makedonka; Nutman, Thomas B; Parkinson, John; Peregrín-Alvarez, José M; Poole, Catherine; Ren, Qinghu; Saunders, Lori; Sluder, Ann E; Smith, Katherine; Stanke, Mario; Unnasch, Thomas R; Ware, Jenna; Wei, Aguan D; Weil, Gary; Williams, Deryck J; Zhang, Yinhua; Williams, Steven A; Fraser-Liggett, Claire; Slatko, Barton; Blaxter, Mark L; Scott, Alan L

    2007-09-21

    Parasitic nematodes that cause elephantiasis and river blindness threaten hundreds of millions of people in the developing world. We have sequenced the approximately 90 megabase (Mb) genome of the human filarial parasite Brugia malayi and predict approximately 11,500 protein coding genes in 71 Mb of robustly assembled sequence. Comparative analysis with the free-living, model nematode Caenorhabditis elegans revealed that, despite these genes having maintained little conservation of local synteny during approximately 350 million years of evolution, they largely remain in linkage on chromosomal units. More than 100 conserved operons were identified. Analysis of the predicted proteome provides evidence for adaptations of B. malayi to niches in its human and vector hosts and insights into the molecular basis of a mutualistic relationship with its Wolbachia endosymbiont. These findings offer a foundation for rational drug design.

  3. A member of the TGF-beta receptor gene family in the parasitic nematode Brugia pahangi.

    PubMed

    Gomez-Escobar, N; van den Biggelaar, A; Maizels, R

    1997-10-15

    The full length cDNA sequence of a Type I transforming growth factor-beta (TGF-beta) receptor has been isolated from the filarial parasitic nematode Brugia pahangi. This new gene, designated Bp-trk-1, encodes a predicted 645 amino acid sequence with an N-terminal hydrophobic stretch which may act as a signal peptide. The extracellular portion (residues 15-187) is cysteine-rich and has three potential N-glycosylation sites. At positions 250-255 the protein contains the glycine-serine rich motif characteristic of Type I receptors. The closest homologue is a Caenorhabditis elegans gene (Q09488) in cosmid C32D5.2 which shares 67% amino acid identity with Bp-trk-1 in the most conserved kinase domain (aa 259-482). Other type I receptors such as C. elegans daf-1 and Drosophila tkv show 38-53% identity in the same region. Some residues conserved in Drosophila and vertebrates are not present in the B. pahangi sequence. RT-PCR amplification has been used to show that the transcript is expressed in the three main stages of the B. pahangi life cycle: microfilariae, infective larvae and adults. The ligand remains unknown at this time but is likely to be most similar to that for C. elegans Q09488. PMID:9358045

  4. Functional and phenotypic characteristics of alternative activation induced in human monocytes by interleukin-4 or the parasitic nematode Brugia malayi.

    PubMed

    Semnani, Roshanak Tolouei; Mahapatra, Lily; Moore, Vanessa; Sanprasert, Vivornpun; Nutman, Thomas B

    2011-10-01

    Human monocytes from patients with patent filarial infections are studded with filarial antigen and express markers associated with alternative activation of macrophages (MΦ). To explore the role of filaria-derived parasite antigen in differentiation of human monocytes, cells were exposed to microfilariae (mf) of Brugia malayi, and their phenotypic and functional characteristics were compared with those of monocytes exposed to factors known to generate either alternatively (interleukin-4 [IL-4]) or classically (macrophage colony-stimulating factor [MCSF]) activated MΦ. IL-4 upregulated mRNA expression of CCL13, CCL15, CCL17, CCL18, CCL22, CLEC10A, MRC1, CADH1, CD274, and CD273 associated with alternative activation of MΦ but not arginase 1. IL-4-cultured monocytes had a diminished ability to promote proliferation of both CD4(+) and CD8(+) T cells compared to that of unexposed monocytes. Similar to results with IL-4, exposure of monocytes to live mf induced upregulation of CCL15, CCL17, CCL18, CCL22, CD274, and CD273 and downregulation of Toll-like receptor 3 (TLR3), TLR5, and TLR7. In contrast to results with MCSF-cultured monocytes, exposure of monocytes to mf resulted in significant inhibition of the phagocytic ability of these cells to the same degree as that seen with IL-4. Our data suggest that short exposure of human monocytes to IL-4 induces a phenotypic characteristic of alternative activation and that secreted filarial products skew monocytes similarly. PMID:21788379

  5. Chitinase is stored and secreted from the inner body of microfilariae and has a role in exsheathment in the parasitic nematode Brugia malayi

    PubMed Central

    Wu, Yang; Preston, Gillian; Bianco, Albert E.

    2008-01-01

    Chitinase expression in microfilariae of the parasitic nematode Brugia malayi (B. malayi, Bm) is coincidental with the onset of their infectivity to mosquitoes. An antibody raised to Onchocerca volvulus (O. volvulus, Ov) infective-stage larval chitinase (Ov-CHI-1) was specifically reactive against B. malayi microfilarial chitinase and was used to study the localization of chitinase in B. malayi during microfilarial development and transmission to the insect vector. Immuno-electron microscopy (IEM) was used to demonstrate that the chitinase was confined to the inner body of the microfilariae and furthermore that chitinase was only present in sheathed microfilarial species, although the inner body is present in all species. Observation using the IEM implicates two distinct routes of chitinase secretion from the inner body, via either the pharyngeal thread, or during transmission of the microfilariae to the vector, contained in vesicle-like structures. Many morphological studies have described the structure of the inner body, but no function has been assigned to it as of yet. Although it has been commented that the cells surrounding the inner body and pharyngeal thread are those destined to become the intestine and pharynx and that the inner body represents a store of material. Our studies suggest that chitinase is one such product stored in the inner body and that it is secreted during the exsheathment of the microfilaria in the mosquito. PMID:18611418

  6. Bacterial endosymbionts of plant-parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several groups of bacteria have been reported as endosymbionts of various orders of nematodes including the filarial nematodes (Brugia malayi, Wucheria bancrofti and Onchocerca volvulus (Spiruida)), the entomopathogenic nematodes (Steinernema spp., and Heterorhabditis spp. (Rhabditida)), and plant-p...

  7. Bm-CPI-2, a cystatin from Brugia malayi nematode parasites, differs from Caenorhabditis elegans cystatins in a specific site mediating inhibition of the antigen-processing enzyme AEP.

    PubMed

    Murray, Janice; Manoury, Bénédicte; Balic, Adam; Watts, Colin; Maizels, Rick M

    2005-02-01

    The filarial parasite Brugia malayi survives for many years in the human lymphatic system. One immune evasion mechanism employed by Brugia is thought to be the release of cysteine protease inhibitors (cystatins), and we have previously shown that the recombinant cystatin Bm-CPI-2 interferes with protease-dependent antigen processing in the MHC class II antigen presentation pathway. Analogy with vertebrate cystatins suggested that Bm-CPI-2 is bi-functional, with one face of the protein blocking papain-like proteases, and the other able to inhibit legumains such as asparaginyl endopeptidase (AEP). Site-directed mutagenesis was carried out on Bm-CPI-2 at Asn-77, the residue on which AEP inhibition is dependent in vertebrate homologues. Two mutations at this site (to Asp and Lys) showed 10-fold diminished and ablated activity respectively, in assays of AEP inhibition, while blocking of papain-like proteases was reduced by only a small degree. Comparison of the B. malayi cystatins with two homologues encoded by the free-living model organism, Caenorhabditis elegans, suggested that while the papain site may be intact, the AEP site would not be functional. This supposition was tested with recombinant C. elegans proteins, Ce-CPI-1 (K08B4.6) and Ce-CPI-2 (R01B10.1), both of which block cathepsins and neither of which possess the ability to block AEP. Thus, Brugia CPI-2 may have convergently evolved to inhibit an enzyme important only in the mammalian environment.

  8. Cytokine production in BALB/c mice immunized with radiation attenuated third stage larvae of the filarial nematode, Brugia pahangi

    SciTech Connect

    Bancroft, A.J.; Devaney, E. ); Grencis, R.K.; Else, K.J. )

    1993-02-15

    BALB/c mice immunized with radiation-attenuated third stage larvae of the filarial nematode Brugia pahangi are strongly immune to challenge infection. Investigation of the profile of cytokines secreted by spleen cells from immune mice stimulated in vitro with either parasite Ag or with Con A revealed high levels of IL-5 and IL-9 and moderate levels of IL-4. In contrast, secretion of IFN-[gamma] by spleen cells from immune animals was negligible. Spleen cells from control mice secreted low levels of all cytokines assayed. Levels of parasite-specific IgE were significantly elevated in immune animals and a peripheral blood eosinophilia was observed, which exhibited a biphasic distribution. Our results are consistent with the preferential expansion of Th2 cells in immune animals and provide the basis for dissecting the means by which radiation-attenuated larvae of filarial nematodes stimulate immunity. 5l refs., 3 figs., 3 tabs.

  9. Release of Small RNA-containing Exosome-like Vesicles from the Human Filarial Parasite Brugia malayi.

    PubMed

    Zamanian, Mostafa; Fraser, Lisa M; Agbedanu, Prince N; Harischandra, Hiruni; Moorhead, Andrew R; Day, Tim A; Bartholomay, Lyric C; Kimber, Michael J

    2015-01-01

    Lymphatic filariasis (LF) is a socio-economically devastating mosquito-borne Neglected Tropical Disease caused by parasitic filarial nematodes. The interaction between the parasite and host, both mosquito and human, during infection, development and persistence is dynamic and delicately balanced. Manipulation of this interface to the detriment of the parasite is a promising potential avenue to develop disease therapies but is prevented by our very limited understanding of the host-parasite relationship. Exosomes are bioactive small vesicles (30-120 nm) secreted by a wide range of cell types and involved in a wide range of physiological processes. Here, we report the identification and partial characterization of exosome-like vesicles (ELVs) released from the infective L3 stage of the human filarial parasite Brugia malayi. Exosome-like vesicles were isolated from parasites in culture media and electron microscopy and nanoparticle tracking analysis were used to confirm that vesicles produced by juvenile B. malayi are exosome-like based on size and morphology. We show that loss of parasite viability correlates with a time-dependent decay in vesicle size specificity and rate of release. The protein cargo of these vesicles is shown to include common exosomal protein markers and putative effector proteins. These Brugia-derived vesicles contain small RNA species that include microRNAs with host homology, suggesting a potential role in host manipulation. Confocal microscopy shows J774A.1, a murine macrophage cell line, internalize purified ELVs, and we demonstrate that these ELVs effectively stimulate a classically activated macrophage phenotype in J774A.1. To our knowledge, this is the first report of exosome-like vesicle release by a human parasitic nematode and our data suggest a novel mechanism by which human parasitic nematodes may actively direct the host responses to infection. Further interrogation of the makeup and function of these bioactive vesicles could seed

  10. Release of Small RNA-containing Exosome-like Vesicles from the Human Filarial Parasite Brugia malayi

    PubMed Central

    Agbedanu, Prince N; Harischandra, Hiruni; Moorhead, Andrew R; Day, Tim A; Bartholomay, Lyric C; Kimber, Michael J

    2015-01-01

    Lymphatic filariasis (LF) is a socio-economically devastating mosquito-borne Neglected Tropical Disease caused by parasitic filarial nematodes. The interaction between the parasite and host, both mosquito and human, during infection, development and persistence is dynamic and delicately balanced. Manipulation of this interface to the detriment of the parasite is a promising potential avenue to develop disease therapies but is prevented by our very limited understanding of the host-parasite relationship. Exosomes are bioactive small vesicles (30–120 nm) secreted by a wide range of cell types and involved in a wide range of physiological processes. Here, we report the identification and partial characterization of exosome-like vesicles (ELVs) released from the infective L3 stage of the human filarial parasite Brugia malayi. Exosome-like vesicles were isolated from parasites in culture media and electron microscopy and nanoparticle tracking analysis were used to confirm that vesicles produced by juvenile B. malayi are exosome-like based on size and morphology. We show that loss of parasite viability correlates with a time-dependent decay in vesicle size specificity and rate of release. The protein cargo of these vesicles is shown to include common exosomal protein markers and putative effector proteins. These Brugia-derived vesicles contain small RNA species that include microRNAs with host homology, suggesting a potential role in host manipulation. Confocal microscopy shows J774A.1, a murine macrophage cell line, internalize purified ELVs, and we demonstrate that these ELVs effectively stimulate a classically activated macrophage phenotype in J774A.1. To our knowledge, this is the first report of exosome-like vesicle release by a human parasitic nematode and our data suggest a novel mechanism by which human parasitic nematodes may actively direct the host responses to infection. Further interrogation of the makeup and function of these bioactive vesicles could seed

  11. Mining predicted essential genes of Brugia malayi for nematode drug targets.

    PubMed

    Kumar, Sanjay; Chaudhary, Kshitiz; Foster, Jeremy M; Novelli, Jacopo F; Zhang, Yinhua; Wang, Shiliang; Spiro, David; Ghedin, Elodie; Carlow, Clotilde K S

    2007-01-01

    We report results from the first genome-wide application of a rational drug target selection methodology to a metazoan pathogen genome, the completed draft sequence of Brugia malayi, a parasitic nematode responsible for human lymphatic filariasis. More than 1.5 billion people worldwide are at risk of contracting lymphatic filariasis and onchocerciasis, a related filarial disease. Drug treatments for filariasis have not changed significantly in over 20 years, and with the risk of resistance rising, there is an urgent need for the development of new anti-filarial drug therapies. The recent publication of the draft genomic sequence for B. malayi enables a genome-wide search for new drug targets. However, there is no functional genomics data in B. malayi to guide the selection of potential drug targets. To circumvent this problem, we have utilized the free-living model nematode Caenorhabditis elegans as a surrogate for B. malayi. Sequence comparisons between the two genomes allow us to map C. elegans orthologs to B. malayi genes. Using these orthology mappings and by incorporating the extensive genomic and functional genomic data, including genome-wide RNAi screens, that already exist for C. elegans, we identify potentially essential genes in B. malayi. Further incorporation of human host genome sequence data and a custom algorithm for prioritization enables us to collect and rank nearly 600 drug target candidates. Previously identified potential drug targets cluster near the top of our prioritized list, lending credibility to our methodology. Over-represented Gene Ontology terms, predicted InterPro domains, and RNAi phenotypes of C. elegans orthologs associated with the potential target pool are identified. By virtue of the selection procedure, the potential B. malayi drug targets highlight components of key processes in nematode biology such as central metabolism, molting and regulation of gene expression.

  12. Role of nitric oxide in host defense against an extracellular, metazoan parasite, Brugia malayi.

    PubMed Central

    Rajan, T V; Porte, P; Yates, J A; Keefer, L; Shultz, L D

    1996-01-01

    The mechanisms by which mammalian hosts eliminate microparasites such as bacteria and viruses are well established. In viral infections, these mechanisms include the interferons, neutralizing and opsonizing antibodies, and cytotoxic T lymphocytes. In bacterial infections, polymorphonuclear leukocytes and macrophages, often facilitated by opsonizing antibodies, ingest the infectious agent and mediate host defense. In addition, complement, in the presence of specific antibodies directed against surface antigens, can lyse certain bacterial pathogens. In contrast, our understanding of the host defenses against metazoan, extracellular parasites is less well grounded. We obtained data by two different approaches to document the role of nitric oxide (NO) as a mediator of host defense against a human nematode parasite. First, treatment of immunocompetent, nonpermissive mice with an inhibitor of NO synthase abrogated resistance to Brugia malayi, one of the causative agents of human lymphatic filariasis. Second, treatment of permissive, immunodeficient mice with a compound that releases NO conferred resistance to infection. These data reinforce studies by James and her coworkers (I. P. Oswald, T. A. Wynn, A. Sher, and S. L. James, Comp. Biochem. Physiol. Pharmacol. Toxicol. Endocrinol. 108:11-18, 1994) on the role of NO in defense against trematode parasites and of Kanazawa et al. (T. Kanazawa, H. Asahi, H. Hata; K. Machida, N. Kagei, and M. J. Stadecker, Parasite Immunol. 15: 619-623, 1993) on cestode parasites. PMID:8757874

  13. Synthesis and activity of substituted anthraquinones against a human filarial parasite, Brugia malayi.

    PubMed

    Dhananjeyan, Mugunthu R; Milev, Youli P; Kron, Michael A; Nair, Muraleedharan G

    2005-04-21

    Lymphatic filariasis (elephantiasis) is a global public health problem caused by the parasitic nematodes Wuchereria bancrofti and Brugia malayi. We have previously reported anthraquinones from daylily roots with potent activity against pathogenic trematode Schistosoma mansoni. Here we report the synthesis of novel anthraquinones A-S and their antifilrarial activity. Anthraquinones A-S were synthesized by a single-step Friedel-Crafts acylation reaction between phthalic anhydrides and substituted benzenes. The antifilarial properties of these synthetic anthraquinones were tested against microfilaria as well as adult male and female worms of B. malayi. The most active anthraquinone was K, which showed 100% mortality within 1, 5, and 3 days, respectively, against microfilaria and adult male and female worms at 5 ppm concentration. Albendazole, an oral drug currently used to treat parasitic infections, was used as a positive control. Methylated products of anthraquinones did not affect the microfilaria. Histological examination of treated adult female parasites showed most of the anthraquinones caused marked effects on intrauterine embryos. PMID:15828820

  14. Nucleic acid transfection and transgenesis in parasitic nematodes.

    PubMed

    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. PMID:21880161

  15. Mechanisms of host seeking by parasitic nematodes.

    PubMed

    Gang, Spencer S; Hallem, Elissa A

    2016-07-01

    The phylum Nematoda comprises a diverse group of roundworms that includes parasites of vertebrates, invertebrates, and plants. Human-parasitic nematodes infect more than one billion people worldwide and cause some of the most common neglected tropical diseases, particularly in low-resource countries [1]. Parasitic nematodes of livestock and crops result in billions of dollars in losses each year [1]. Many nematode infections are treatable with low-cost anthelmintic drugs, but repeated infections are common in endemic areas and drug resistance is a growing concern with increasing therapeutic and agricultural administration [1]. Many parasitic nematodes have an environmental infective larval stage that engages in host seeking, a process whereby the infective larvae use sensory cues to search for hosts. Host seeking is a complex behavior that involves multiple sensory modalities, including olfaction, gustation, thermosensation, and humidity sensation. As the initial step of the parasite-host interaction, host seeking could be a powerful target for preventative intervention. However, host-seeking behavior remains poorly understood. Here we review what is currently known about the host-seeking behaviors of different parasitic nematodes, including insect-parasitic nematodes, mammalian-parasitic nematodes, and plant-parasitic nematodes. We also discuss the neural bases of these behaviors.

  16. Mechanisms of host seeking by parasitic nematodes.

    PubMed

    Gang, Spencer S; Hallem, Elissa A

    2016-07-01

    The phylum Nematoda comprises a diverse group of roundworms that includes parasites of vertebrates, invertebrates, and plants. Human-parasitic nematodes infect more than one billion people worldwide and cause some of the most common neglected tropical diseases, particularly in low-resource countries [1]. Parasitic nematodes of livestock and crops result in billions of dollars in losses each year [1]. Many nematode infections are treatable with low-cost anthelmintic drugs, but repeated infections are common in endemic areas and drug resistance is a growing concern with increasing therapeutic and agricultural administration [1]. Many parasitic nematodes have an environmental infective larval stage that engages in host seeking, a process whereby the infective larvae use sensory cues to search for hosts. Host seeking is a complex behavior that involves multiple sensory modalities, including olfaction, gustation, thermosensation, and humidity sensation. As the initial step of the parasite-host interaction, host seeking could be a powerful target for preventative intervention. However, host-seeking behavior remains poorly understood. Here we review what is currently known about the host-seeking behaviors of different parasitic nematodes, including insect-parasitic nematodes, mammalian-parasitic nematodes, and plant-parasitic nematodes. We also discuss the neural bases of these behaviors. PMID:27211240

  17. Parasitic Nematodes - From Genomes to Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diseases caused by parasitic nematodes in domestic and companion animals are major factors that decrease production and quality of the agricultural products. Methods available for the control of the parasitic nematode infections are mainly based on chemical treatment, non-chemical management pra...

  18. An eye on RNAi in nematode parasites.

    PubMed

    Maule, Aaron G; McVeigh, Paul; Dalzell, Johnathan J; Atkinson, Louise; Mousley, Angela; Marks, Nikki J

    2011-11-01

    RNA interference (RNAi) has revolutionised approaches to gene function determination. From a parasitology perspective, gene function studies have the added dimension of providing validation data, increasingly deemed essential to the initial phases of drug target selection, pre-screen development. Notionally advantageous to those working on nematode parasites is the fact that Caenorhabditis elegans research spawned RNAi discovery and continues to seed our understanding of its fundamentals. Unfortunately, RNAi data for nematode parasites illustrate variable and inconsistent susceptibilities which undermine confidence and exploitation. Now well-ensconced in an era of nematode parasite genomics, we can begin to unscramble this variation.

  19. UDP-galactopyranose mutase, a potential drug target against human pathogenic nematode Brugia malayi.

    PubMed

    Misra, Sweta; Valicherla, Guru R; Mohd Shahab; Gupta, Jyoti; Gayen, Jiaur R; Misra-Bhattacharya, Shailja

    2016-08-01

    Lymphatic filariasis, a vector-borne neglected tropical disease affects millions of population in tropical and subtropical countries. Vaccine unavailability and emerging drug resistance against standard antifilarial drugs necessitate search of novel drug targets for developing alternate drugs. Recently, UDP-galactopyranose mutases (UGM) have emerged as a promising drug target playing an important role in parasite virulence and survival. This study deals with the cloning and characterization of Brugia malayi UGM and further exploring its antifilarial drug target potential. The recombinant protein was actively involved in conversion of UDP-galactopyranose (substrate) to UDP-galactofuranose (product) revealing Km and Vmax to be ∼51.15 μM and ∼1.27 μM/min, respectively. The purified protein appeared to be decameric in native state and its 3D homology modeling using Aspergillus fumigatus UGM enzyme as template revealed conservation of active site residues. Two specific prokaryotic inhibitors (compounds A and B) of the enzyme inhibited B. malayi UGM enzymatic activity competitively depicting Ki values ∼22.68 and ∼23.0 μM, respectively. These compounds were also active in vitro and in vivo against B. malayi The findings suggest that B. malayi UGM could be a potential antifilarial therapeutic drug target. PMID:27465638

  20. A checklist of nematode parasites from Indonesian murids.

    PubMed

    Dewi, Kartika; Purwaningsih, Endang

    2013-01-24

    A checklist of nematode parasites from Indonesian murids with their geographic distribution is presented. This checklist is compiled from three sources: the catalogue of nematode parasites of Museum Zoologicum Bogoriense (unpublished specimens in the collection), data from our previous research and articles on nematodes of Indonesian murids. This checklist is presented as a list of nematode parasites with host information, and a host list with information on their nematodes. This paper reports 38 nominal species of nematodes and 13 species identified to the generic level only. The nematodes reported comprise 32 genera and 17 families parasitizing 32 species of Indonesian murids.

  1. Interdomain lateral gene transfer of an essential ferrochelatase gene in human parasitic nematodes.

    PubMed

    Wu, Bo; Novelli, Jacopo; Jiang, Daojun; Dailey, Harry A; Landmann, Frédéric; Ford, Louise; Taylor, Mark J; Carlow, Clotilde K S; Kumar, Sanjay; Foster, Jeremy M; Slatko, Barton E

    2013-05-01

    Lateral gene transfer events between bacteria and animals highlight an avenue for evolutionary genomic loss/gain of function. Herein, we report functional lateral gene transfer in animal parasitic nematodes. Members of the Nematoda are heme auxotrophs, lacking the ability to synthesize heme; however, the human filarial parasite Brugia malayi has acquired a bacterial gene encoding ferrochelatase (BmFeCH), the terminal step in heme biosynthesis. BmFeCH, encoded by a 9-exon gene, is a mitochondrial-targeted, functional ferrochelatase based on enzyme assays, complementation, and inhibitor studies. Homologs have been identified in several filariae and a nonfilarial nematode. RNAi and ex vivo inhibitor experiments indicate that BmFeCH is essential for viability, validating it as a potential target for filariasis control.

  2. Interdomain lateral gene transfer of an essential ferrochelatase gene in human parasitic nematodes

    PubMed Central

    Wu, Bo; Novelli, Jacopo; Jiang, Daojun; Dailey, Harry A.; Landmann, Frédéric; Ford, Louise; Taylor, Mark J.; Carlow, Clotilde K. S.; Kumar, Sanjay; Foster, Jeremy M.; Slatko, Barton E.

    2013-01-01

    Lateral gene transfer events between bacteria and animals highlight an avenue for evolutionary genomic loss/gain of function. Herein, we report functional lateral gene transfer in animal parasitic nematodes. Members of the Nematoda are heme auxotrophs, lacking the ability to synthesize heme; however, the human filarial parasite Brugia malayi has acquired a bacterial gene encoding ferrochelatase (BmFeCH), the terminal step in heme biosynthesis. BmFeCH, encoded by a 9-exon gene, is a mitochondrial-targeted, functional ferrochelatase based on enzyme assays, complementation, and inhibitor studies. Homologs have been identified in several filariae and a nonfilarial nematode. RNAi and ex vivo inhibitor experiments indicate that BmFeCH is essential for viability, validating it as a potential target for filariasis control. PMID:23610429

  3. Rendering the Intractable More Tractable: Tools from Caenorhabditis elegans Ripe for Import into Parasitic Nematodes.

    PubMed

    Ward, Jordan D

    2015-12-01

    Recent and rapid advances in genetic and molecular tools have brought spectacular tractability to Caenorhabditis elegans, a model that was initially prized because of its simple design and ease of imaging. C. elegans has long been a powerful model in biomedical research, and tools such as RNAi and the CRISPR/Cas9 system allow facile knockdown of genes and genome editing, respectively. These developments have created an additional opportunity to tackle one of the most debilitating burdens on global health and food security: parasitic nematodes. I review how development of nonparasitic nematodes as genetic models informs efforts to import tools into parasitic nematodes. Current tools in three commonly studied parasites (Strongyloides spp., Brugia malayi, and Ascaris suum) are described, as are tools from C. elegans that are ripe for adaptation and the benefits and barriers to doing so. These tools will enable dissection of a huge array of questions that have been all but completely impenetrable to date, allowing investigation into host-parasite and parasite-vector interactions, and the genetic basis of parasitism. PMID:26644478

  4. Rendering the Intractable More Tractable: Tools from Caenorhabditis elegans Ripe for Import into Parasitic Nematodes.

    PubMed

    Ward, Jordan D

    2015-12-01

    Recent and rapid advances in genetic and molecular tools have brought spectacular tractability to Caenorhabditis elegans, a model that was initially prized because of its simple design and ease of imaging. C. elegans has long been a powerful model in biomedical research, and tools such as RNAi and the CRISPR/Cas9 system allow facile knockdown of genes and genome editing, respectively. These developments have created an additional opportunity to tackle one of the most debilitating burdens on global health and food security: parasitic nematodes. I review how development of nonparasitic nematodes as genetic models informs efforts to import tools into parasitic nematodes. Current tools in three commonly studied parasites (Strongyloides spp., Brugia malayi, and Ascaris suum) are described, as are tools from C. elegans that are ripe for adaptation and the benefits and barriers to doing so. These tools will enable dissection of a huge array of questions that have been all but completely impenetrable to date, allowing investigation into host-parasite and parasite-vector interactions, and the genetic basis of parasitism.

  5. Evolution of plant parasitism among nematodes.

    PubMed

    Baldwin, J G; Nadler, S A; Adams, B J

    2004-01-01

    Despite extraordinary diversity of free-living species, a comparatively small fraction of nematodes are parasites of plants. These parasites represent at least three disparate clades in the nematode tree of life, as inferred from rRNA sequences. Plant parasites share functional similarities regarding feeding, but many similarities in feeding structures result from convergent evolution and have fundamentally different developmental origins. Although Tylenchida rRNA phylogenies are not fully resolved, they strongly support convergent evolution of sedentary endoparasitism and plant nurse cells in cyst and root-knot nematodes. This result has critical implications for using model systems and genomics to identify and characterize parasitism genes for representatives of this clade. Phylogenetic studies reveal that plant parasites have rich and complex evolutionary histories that involve multiple transitions to plant parasitism and the possible use of genes obtained by horizontal transfer from prokaryotes. Developing a fuller understanding of plant parasitism will require integrating more comprehensive and resolved phylogenies with appropriate choices of model organisms and comparative evolutionary methods.

  6. Novel parasitic nematode-specific protein of bovine filarial parasite Setaria digitata displays conserved gene structure and ubiquitous expression.

    PubMed

    Rodrigo, W W; Dassanayake, R S; Weerasena, S J; Silva Gunawardene, Y I

    2014-09-01

    Setaria digitata is an animal filarial parasite, which can cause fatal diseases to livestock such as cattle, sheep, goat, buffaloes, horses etc. inflicting considerable economic losses to livelihood of livestock farmers. In spite of this, the biology and parasitic nature of this organism is largely unknown. As a step towards understanding these, we screened the cDNA library of S. digitata and identified an open reading frame that code for parasitic nematode-specific protein, which showed a significant homology to functionally and structurally unannotated sequences of parasitic nematodes Wuchereria bancrofti, Brugia malayi, Onchocerca volvulus, Loa loa etc., suggesting its role in parasitism. RT-PCR analysis indicated that the S. digitata novel gene (SDNP) is expressed in adult female and male, and microfilariae. Southern hybridization studies revealed that this gene is a single-copy gene. Sequence analysis of the genomic region obtained from overlapping PCR amplification indicated that the size of the genomic region is 1819 bp in which four exons encoding 205 amino acids were interrupted by three introns of varying lengths of 419, 659 and 123 bp, and also the expansion of the size of the introns of S. digitata compared to its orthologues by integrating micro and mini-satellite containing sequence. Sequences around the splice junctions were conserved and agreed with the general GT-AG splicing rule. The gene was found to be AT rich with a GC content of 38.1%. Bioinformatic analysis indicated that the gene structure of SDNP and its orthologues is conserved and it expressed ubiqutously in all the stages of nematode's life cycle. Therefore, taking these outcomes together, it can be concluded that SDNP is a parasitic nematode-specific, single copy gene having conserved gene structure of four exons interrupted by three introns and that the gene is expressed ubiquitously throughout nematode's life cycle. PMID:25382479

  7. Rendering the Intractable More Tractable: Tools from Caenorhabditis elegans Ripe for Import into Parasitic Nematodes

    PubMed Central

    Ward, Jordan D.

    2015-01-01

    Recent and rapid advances in genetic and molecular tools have brought spectacular tractability to Caenorhabditis elegans, a model that was initially prized because of its simple design and ease of imaging. C. elegans has long been a powerful model in biomedical research, and tools such as RNAi and the CRISPR/Cas9 system allow facile knockdown of genes and genome editing, respectively. These developments have created an additional opportunity to tackle one of the most debilitating burdens on global health and food security: parasitic nematodes. I review how development of nonparasitic nematodes as genetic models informs efforts to import tools into parasitic nematodes. Current tools in three commonly studied parasites (Strongyloides spp., Brugia malayi, and Ascaris suum) are described, as are tools from C. elegans that are ripe for adaptation and the benefits and barriers to doing so. These tools will enable dissection of a huge array of questions that have been all but completely impenetrable to date, allowing investigation into host–parasite and parasite–vector interactions, and the genetic basis of parasitism. PMID:26644478

  8. Homologs of the Caenorhabditis elegans masculinizing gene her-1 in C. briggsae and the filarial parasite Brugia malayi.

    PubMed Central

    Streit, A; Li, W; Robertson, B; Schein, J; Kamal, I H; Marra, M; Wood, W B

    1999-01-01

    The masculinizing gene her-1 in Caenorhabditis elegans (Ce-her-1) encodes a novel protein, HER-1A, which is required for male development. To identify conserved elements in her-1 we have cloned and characterized two homologous nematode genes: one by synteny from the closely related free-living species C. briggsae (Cb-her-1) and the other, starting with a fortuitously identified expressed sequence tag, from the distantly related parasite Brugia malayi (Bm-her-1). The overall sequence identities of the predicted gene products with Ce-HER-1A are only 57% for Cb-HER-1, which is considerably lower than has been found for most homologous briggsae genes, and 35% for Bm-HER-1. However, conserved residues are found throughout both proteins, and like Ce-HER-1A, both have putative N-terminal signal sequences. Ce-her-1 produces a larger masculinizing transcript (her-1a) and a smaller transcript of unknown function (her-1b); both are present essentially only in males. By contrast, Cb-her-1 appears to produce only one transcript, corresponding to her-1a; it is enriched in males but present also in hermaphrodites. Injection of dsRNA transcribed from Cb-her-1 into C. briggsae hermaphrodites (RNA interference) caused XO animals to develop into partially fertile hermaphrodites. Introducing a Cb-her-1 construct as a transgene under control of the C. elegans unc-54 myosin heavy chain promoter caused strong masculinization of both C. briggsae and C. elegans hermaphrodites. Introduction of a similar Bm-her-1 construct into C. elegans caused only very weak, if any, masculinization. We conclude that in spite of considerable divergence the Cb gene is likely to be a functional ortholog of Ce-her-1, while the function of the distantly related Bm gene remains uncertain. PMID:10430584

  9. Remote Sensing of Parasitic Nematodes in Plants

    NASA Technical Reports Server (NTRS)

    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.

  10. [Research Progress on Genetic Diversity in Animal Parasitic Nematodes].

    PubMed

    YIN, Fang-yuan; LI, Fa-cai; ZHAO, Jun-long; HU, Min

    2015-10-01

    The development of molecular genetic markers for parasitic nematodes has significant implications in fundamental and applied research in Veterinary Parasitology. Knowledge on genetic diversity of nematodes would not only provide a theoretical basis for understanding the spread of drug-resistance alleles, but also have implications in the development of nematode control strategies. This review discusses the applications of molecular genetic markers (RFLP, RAPD, PCR-SSCP, AFLP, SSR and mitochondrial DNA) in research on the genetic diversity of parasitic nematodes.

  11. [Research Progress on Genetic Diversity in Animal Parasitic Nematodes].

    PubMed

    YIN, Fang-yuan; LI, Fa-cai; ZHAO, Jun-long; HU, Min

    2015-10-01

    The development of molecular genetic markers for parasitic nematodes has significant implications in fundamental and applied research in Veterinary Parasitology. Knowledge on genetic diversity of nematodes would not only provide a theoretical basis for understanding the spread of drug-resistance alleles, but also have implications in the development of nematode control strategies. This review discusses the applications of molecular genetic markers (RFLP, RAPD, PCR-SSCP, AFLP, SSR and mitochondrial DNA) in research on the genetic diversity of parasitic nematodes. PMID:26931047

  12. Moxidectin causes adult worm mortality of human lymphatic filarial parasite Brugia malayi in rodent models.

    PubMed

    Verma, Meenakshi; Pathak, Manisha; Shahab, Mohd; Singh, Kavita; Mitra, Kalyan; Misra-Bhattacharya, Shailja

    2014-12-01

    Moxidectin is a macrocyclic lactone belonging to milbemycin family closely related to ivermectin and is currently progressing towards Phase III clinical trial against human infection with the filaria Onchocerca volvulus (Leuckart, 1894). There is a single report on the microfilaricidal and embryostatic activity of moxidectin in case of the human lymphatic filarial parasite Brugia malayi (Brug, 1927) in Mastomys coucha (Smith) but without any adulticidal action. In the present study, the in vitro and in vivo antifilarial efficacy of moxidectin was evaluated on, B. malayi. In vitro moxidectin showed 100% reduction in adult female worm motility at 0.6 μM concentration within 7 days with 68% inhibition in the reduction of MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide dye) (which is used to detect viability of worms). A 50% inhibitory concentration (IC50) of moxidectin for adult female parasite was 0.242 μM, for male worm 0.186 μM and for microfilaria IC50 was 0.813 μM. In adult B. malayi-transplanted primary screening model (Meriones unguiculatus Milne-Edwards), moxidectin at a single optimal dose of 20 mg/kg by oral and subcutaneous route was found effective on both adult parasites and microfilariae. In secondary screening (M coucha, subcutaneously inoculated with infective larvae), moxidectin at the same dose by subcutaneous route brought about death of 49% of adult worms besides causing sterilisation in 54% of the recovered live female worms. The treated animals exhibited a continuous and sustained reduction in peripheral blood microfilaraemia throughout the observation period of 90 days. The mechanism of action of moxidectin is suggested to be similar to avermectins. The in silico studies were also designed to explore the interaction of moxidectin with glutamate-gated chloride channels of B. malayi. The docking results revealed a close interaction of moxidectin with various GluCl ligand sites of B. malayi. PMID:25651699

  13. Genomics of reproduction in nematodes: prospects for parasite intervention?

    PubMed

    Nisbet, Alasdair J; Cottee, Pauline A; Gasser, Robin B

    2008-02-01

    Understanding reproductive processes in parasitic nematodes has the potential to lead to the informed design of new anthelmintics and control strategies. Little is known, however, about the molecular mechanisms underlying sex determination, gametogenesis and reproductive physiology for most parasitic nematodes. Together with comparative analyses of data for the free-living nematode Caenorhabditis elegans, molecular investigations are beginning to provide insights into the processes involved in reproduction and development in parasitic nematodes. Here, we review recent developments, focusing on technological aspects and on molecules associated with sex-specific differences in adult nematodes. PMID:18182326

  14. Diversity and Expression of MicroRNAs in the Filarial Parasite, Brugia malayi

    PubMed Central

    Poole, Catherine B.; Gu, Weifeng; Kumar, Sanjay; Jin, Jingmin; Davis, Paul J.; Bauche, David; McReynolds, Larry A.

    2014-01-01

    Human filarial parasites infect an estimated 120 million people in 80 countries worldwide causing blindness and the gross disfigurement of limbs and genitals. An understanding of RNA-mediated regulatory pathways in these parasites may open new avenues for treatment. Toward this goal, small RNAs from Brugia malayi adult females, males and microfilariae were cloned for deep-sequencing. From ∼30 million sequencing reads, 145 miRNAs were identified in the B. malayi genome. Some microRNAs were validated using the p19 RNA binding protein and qPCR. B. malayi miRNAs segregate into 99 families each defined by a unique seed sequence. Sixty-one of the miRNA families are highly conserved with homologues in arthropods, vertebrates and helminths. Of those miRNAs not highly conserved, homologues of 20 B. malayi miRNA families were found in vertebrates. Nine B. malayi miRNA families appear to be filarial-specific as orthologues were not found in other organisms. The miR-2 family is the largest in B. malayi with 11 members. Analysis of the sequences shows that six members result from a recent expansion of the family. Library comparisons found that 1/3 of the B. malayi miRNAs are differentially expressed. For example, miR-71 is 5–7X more highly expressed in microfilariae than adults. Studies suggest that in C.elegans, miR-71 may enhance longevity by targeting the DAF-2 pathway. Characterization of B. malayi miRNAs and their targets will enhance our understanding of their regulatory pathways in filariads and aid in the search for novel therapeutics. PMID:24824352

  15. Diversity and expression of microRNAs in the filarial parasite, Brugia malayi.

    PubMed

    Poole, Catherine B; Gu, Weifeng; Kumar, Sanjay; Jin, Jingmin; Davis, Paul J; Bauche, David; McReynolds, Larry A

    2014-01-01

    Human filarial parasites infect an estimated 120 million people in 80 countries worldwide causing blindness and the gross disfigurement of limbs and genitals. An understanding of RNA-mediated regulatory pathways in these parasites may open new avenues for treatment. Toward this goal, small RNAs from Brugia malayi adult females, males and microfilariae were cloned for deep-sequencing. From ∼ 30 million sequencing reads, 145 miRNAs were identified in the B. malayi genome. Some microRNAs were validated using the p19 RNA binding protein and qPCR. B. malayi miRNAs segregate into 99 families each defined by a unique seed sequence. Sixty-one of the miRNA families are highly conserved with homologues in arthropods, vertebrates and helminths. Of those miRNAs not highly conserved, homologues of 20 B. malayi miRNA families were found in vertebrates. Nine B. malayi miRNA families appear to be filarial-specific as orthologues were not found in other organisms. The miR-2 family is the largest in B. malayi with 11 members. Analysis of the sequences shows that six members result from a recent expansion of the family. Library comparisons found that 1/3 of the B. malayi miRNAs are differentially expressed. For example, miR-71 is 5-7X more highly expressed in microfilariae than adults. Studies suggest that in C.elegans, miR-71 may enhance longevity by targeting the DAF-2 pathway. Characterization of B. malayi miRNAs and their targets will enhance our understanding of their regulatory pathways in filariads and aid in the search for novel therapeutics.

  16. Parasitic Nematode Immunomodulatory Strategies: Recent Advances and Perspectives.

    PubMed

    Cooper, Dustin; Eleftherianos, Ioannis

    2016-01-01

    More than half of the described species of the phylum Nematoda are considered parasitic, making them one of the most successful groups of parasites. Nematodes are capable of inhabiting a wide variety of niches. A vast array of vertebrate animals, insects, and plants are all identified as potential hosts for nematode parasitization. To invade these hosts successfully, parasitic nematodes must be able to protect themselves from the efficiency and potency of the host immune system. Innate immunity comprises the first wave of the host immune response, and in vertebrate animals it leads to the induction of the adaptive immune response. Nematodes have evolved elegant strategies that allow them to evade, suppress, or modulate host immune responses in order to persist and spread in the host. Nematode immunomodulation involves the secretion of molecules that are capable of suppressing various aspects of the host immune response in order to promote nematode invasion. Immunomodulatory mechanisms can be identified in parasitic nematodes infecting insects, plants, and mammals and vary greatly in the specific tactics by which the parasites modify the host immune response. Nematode-derived immunomodulatory effects have also been shown to affect, negatively or positively, the outcome of some concurrent diseases suffered by the host. Understanding nematode immunomodulatory actions will potentially reveal novel targets that will in turn lead to the development of effective means for the control of destructive nematode parasites. PMID:27649248

  17. Parasitic Nematode Immunomodulatory Strategies: Recent Advances and Perspectives

    PubMed Central

    Cooper, Dustin; Eleftherianos, Ioannis

    2016-01-01

    More than half of the described species of the phylum Nematoda are considered parasitic, making them one of the most successful groups of parasites. Nematodes are capable of inhabiting a wide variety of niches. A vast array of vertebrate animals, insects, and plants are all identified as potential hosts for nematode parasitization. To invade these hosts successfully, parasitic nematodes must be able to protect themselves from the efficiency and potency of the host immune system. Innate immunity comprises the first wave of the host immune response, and in vertebrate animals it leads to the induction of the adaptive immune response. Nematodes have evolved elegant strategies that allow them to evade, suppress, or modulate host immune responses in order to persist and spread in the host. Nematode immunomodulation involves the secretion of molecules that are capable of suppressing various aspects of the host immune response in order to promote nematode invasion. Immunomodulatory mechanisms can be identified in parasitic nematodes infecting insects, plants, and mammals and vary greatly in the specific tactics by which the parasites modify the host immune response. Nematode-derived immunomodulatory effects have also been shown to affect, negatively or positively, the outcome of some concurrent diseases suffered by the host. Understanding nematode immunomodulatory actions will potentially reveal novel targets that will in turn lead to the development of effective means for the control of destructive nematode parasites. PMID:27649248

  18. Transgenesis in the parasitic nematode Strongyloides ratti

    PubMed Central

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

    2011-01-01

    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 S. 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. PMID:21723330

  19. Biological control of nematode parasites in sheep.

    PubMed

    Larsen, M

    2006-04-01

    In a world in which sheep producers are facing increasing problems due to the rapid spread of anthelmintic resistance, the battle against gastrointestinal parasitic nematodes is a difficult one. One of the potential new tools for integrated control strategies is biological control by means of the nematode-destroying microfungus Duddingtonia flagrans. This fungus forms sticky traps that catch developing larval stages of parasitic nematodes in the fecal environment. When resting spores (chlamydospores) of this fungus are fed daily to grazing animals for a period of time, the pasture infectivity and thus, the worm burden of grazing animals are lowered, especially in young lambs. Research has been conducted throughout the world covering many different climates and management systems. An Australian parasite model showed that if the fungus performs efficiently (> or =90% reduction in worm burden) for 2 or 3 mo, it should contribute significantly to a reduction in the number of dead lambs otherwise occurring when managed only by anthelmintic treatment and grazing management. Feeding or field trials have clearly demonstrated that dosing with a few hundred thousand spores per kilogram of live BW not only reduced the number of infective larvae but also increased the BW of the lambs compared with controls not given fungus. Initial Australian work with feeding spores by means of a block formulation or a slow-release device has shown some promise, but further work is needed to fully develop these delivery systems. In tropical Malaysia, small paddock trials and field studies resulted in significant improvements, in terms of lower worm burdens and increased live BW, when feeding half a million spores daily to grazing lambs. Additional benefits have been observed when the fungus is employed in combination with a fast rotational grazing system. Research has also demonstrated that spores can be delivered in slightly moist feed block material, but only if such blocks are consumed

  20. Nematode parasite genes: what's in a name?

    PubMed

    Beech, Robin N; Wolstenholme, Adrian J; Neveu, Cédric; Dent, Joseph A

    2010-07-01

    The central theme of Shakespeare's Romeo and Juliet is that names are meaningless, artificial constructs, detached from any underlying reality. By contrast, we argue that a well chosen gene name can concisely convey a wealth of relevant biological information. A consistent nomenclature adds transparency that can have a real impact on our understanding of gene function. Currently, genes in parasitic nematodes are often named ad hoc, leading to confusion that can be resolved by adherence to a nomenclature standard adapted from Caenorhabditis elegans. We demonstrate this with ligand-gated ion-channels and propose that the flood of genome data and differences between parasites and the free living C. elegans will require modification of the standard.

  1. The genome of Brugia malayi - all worms are not created equal.

    PubMed

    Scott, Alan L; Ghedin, Elodie

    2009-03-01

    Filarial nematode parasites, the causative agents of elephantiasis and river blindness, undermine the livelihoods of over one hundred million people in the developing world. Recently, the Filarial Genome Project reported the draft sequence of the ~95 Mb genome of the human filarial parasite Brugia malayi - the first parasitic nematode genome to be sequenced. Comparative genome analysis with the prevailing model nematode Caenorhabditis elegans revealed similarities and differences in genome structure and organization that will prove useful as additional nematode genomes are completed. The Brugia genome provides the first opportunity to comprehensively compare the full gene repertoire of a free-living nematode species and one that has evolved as a human pathogen. The Brugia genome also provides an opportunity to gain insight into genetic basis for mutualism, as Brugia, like a majority of filarial species, harbors an endosybiotic bacterium (Wolbachia). The goal of this review is to provide an overview of the results of genomic analysis and how these observations provide new insights into the biology of filarial species. PMID:18952001

  2. In vitro flubendazole-induced damage to vital tissues in adult females of the filarial nematode Brugia malayi

    PubMed Central

    O'Neill, Maeghan; Geary, James F.; Agnew, Dalen W.; Mackenzie, Charles D.; Geary, Timothy G.

    2015-01-01

    The use of a microfilaricidal drug for the control of onchocerciasis and lymphatic filariasis necessitates prolonged yearly dosing. Prospects for elimination or eradication of these diseases would be enhanced by availability of a macrofilaricidal drug. Flubendazole (FLBZ), a benzimidazole anthelmintic, is an appealing candidate macrofilaricide. FLBZ has demonstrated profound and potent macrofilaricidal effects in a number of experimental filarial rodent models and one human trial. Unfortunately, FLBZ was deemed unsatisfactory for use in mass drug administration (MDA) campaigns due to its markedly limited oral bioavailability. However, a new formulation that provided sufficient bioavailability following oral administration could render FLBZ an effective treatment for onchocerciasis and LF. This study characterized the effects of FLBZ and its reduced metabolite (FLBZ-R) on filarial nematodes in vitro to determine the exposure profile which results in demonstrable damage. Adult female Brugia malayi were exposed to varying concentrations of FLBZ or FLBZ-R (100 nM–10 μM) for up to five days, after which worms were fixed for histology. Morphological damage following exposure to FLBZ was observed prominently in the hypodermis and developing embryos at concentrations as low as 100 nM following 24 h exposure. The results indicate that damage to tissues required for reproduction and survival can be achieved at pharmacologically relevant concentrations. PMID:26288741

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

    PubMed

    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. PMID:25656361

  4. Orthologs of macrophage migration inhibitory factor from parasitic nematodes

    PubMed Central

    Vermeire, Jon J.; Cho, Yoonsang; Lolis, Elias; Bucala, Richard; Cappello, Michael

    2013-01-01

    Chronic helminth infections are associated with modulation of host cellular immune responses, presumably to prolong parasite survival within the mammalian host. This phenomenon is attributed, at least in part, to the elaboration of parasite molecules, including orthologs of host cytokines and receptors, at the host–parasite interface. This review describes recent progress in the characterization of macrophage migration inhibitory factor (MIF) orthologs from parasitic nematodes. The roles of these molecules in parasite developmental biology and pathogenesis are discussed. Further knowledge of the species-specific activities and three-dimensional structures of human and parasitic nematode MIF molecules should make them ideal targets for drug- and/or vaccine-based strategies aimed at nematode disease control. PMID:18603473

  5. Directional movement of parasitic nematodes in response to electrical current

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Steinernematid nematodes are parasites that are important natural regulating agents of insect populations. The infective juvenile nematodes respond to a variety of stimuli that aid in survival and host finding. Host finding strategies among steinernematids differ along a continuum from ambush (sit...

  6. Nematode parasites of Chelidae (Testudines) from southern Brazil.

    PubMed

    Mascarenhas, Carolina S; Souza, Jéssica D; Coimbra, Marco Antônio A; Müller, Gertrud

    2013-09-01

    The presence of helminths associated with freshwater turtles is rarely reported. There are no records of nematodes parasitizing Acanthochelys spixii, and for Hydromedusa tectifera, there is only the report of unidentified nematodes found in this species in Argentina. This is the first report of nematodes (Spiroxys contortus and Camallanus sp.) in A. spixii and the first record of Spiroxys contortus and Camallanus sp. in H. tectifera. This is the southernmost record of S . contortus because this nematode was previously recorded only in Mexico. PMID:23812643

  7. Cofactor-independent phosphoglycerate mutase has an essential role in Caenorhabditis elegans and is conserved in parasitic nematodes.

    PubMed

    Zhang, Yinhua; Foster, Jeremy M; Kumar, Sanjay; Fougere, Marjorie; Carlow, Clotilde K S

    2004-08-27

    Phosphoglycerate mutases catalyze the interconversion of 2- and 3-phosphoglycerate in the glycolytic and gluconeogenic pathways. They exist in two unrelated forms that are either cofactor (2,3-diphosphoglycerate)-dependent or cofactor-independent. The two enzymes have no similarity in amino acid sequence, tertiary structure, or catalytic mechanism. Certain organisms including vertebrates have only the cofactor-dependent form, whereas other organisms can possess the independent form or both. Caenorhabditis elegans has been predicted to have only independent phosphoglycerate mutase. In this study, we have cloned and produced recombinant, independent phosphoglycerate mutases from C. elegans and the human-parasitic nematode Brugia malayi. They are 70% identical to each other and related to known bacterial, fungal, and protozoan enzymes. The nematode enzymes possess the catalytic serine, and other key amino acids proposed for catalysis and recombinant enzymes showed typical phosphoglycerate mutase activities in both the glycolytic and gluconeogenic directions. The gene is essential in C. elegans, because the reduction of its activity by RNA interference led to embryonic lethality, larval lethality, and abnormal body morphology. Promoter reporter analysis indicated widespread expression in larval and adult C. elegans with the highest levels apparent in the nerve ring, intestine, and body wall muscles. The enzyme was found in a diverse group of nematodes representing the major clades, indicating that it is conserved throughout this phylum. Our results demonstrate that nematodes, unlike vertebrates, utilize independent phosphoglycerate mutase in glycolytic and gluconeogenic pathways and that the enzyme is probably essential for all nematodes.

  8. Soil Organic Matter and Management of Plant-Parasitic Nematodes

    PubMed Central

    Widmer, T. L.; Mitkowski, N. A.; Abawi, G. S.

    2002-01-01

    Organic matter and its replenishment has become a major component of soil health management programs. Many of the soil's physical, chemical, and biological properties are a function of organic matter content and quality. Adding organic matter to soil influences diverse and important biological activities. The diversity and number of free-living and plant-parasitic nematodes are altered by rotational crops, cover crops, green manures, and other sources of organic matter. Soil management programs should include the use of the proper organic materials to improve soil chemical, physical, and biological parameters and to suppress plant-parasitic nematodes and soilborne pathogens. It is critical to monitor the effects of organic matter additions on activities of major and minor plant-parasitic nematodes in the production system. This paper presents a general review of information in the literature on the effects of crop rotation, cover crops, and green manures on nematodes and their damage to economic crops. PMID:19265946

  9. Sequence mining and transcript profiling to explore cyst nematode parasitism

    PubMed Central

    Elling, Axel A; Mitreva, Makedonka; Gai, Xiaowu; Martin, John; Recknor, Justin; Davis, Eric L; Hussey, Richard S; Nettleton, Dan; McCarter, James P; Baum, Thomas J

    2009-01-01

    Background Cyst nematodes are devastating plant parasites that become sedentary within plant roots and induce the transformation of normal plant cells into elaborate feeding cells with the help of secreted effectors, the parasitism proteins. These proteins are the translation products of parasitism genes and are secreted molecular tools that allow cyst nematodes to infect plants. Results We present here the expression patterns of all previously described parasitism genes of the soybean cyst nematode, Heterodera glycines, in all major life stages except the adult male. These insights were gained by analyzing our gene expression dataset from experiments using the Affymetrix Soybean Genome Array GeneChip, which contains probeset sequences for 6,860 genes derived from preparasitic and parasitic H. glycines life stages. Targeting the identification of additional H. glycines parasitism-associated genes, we isolated 633 genes encoding secretory proteins using algorithms to predict secretory signal peptides. Furthermore, because some of the known H. glycines parasitism proteins have strongest similarity to proteins of plants and microbes, we searched for predicted protein sequences that showed their highest similarities to plant or microbial proteins and identified 156 H. glycines genes, some of which also contained a signal peptide. Analyses of the expression profiles of these genes allowed the formulation of hypotheses about potential roles in parasitism. This is the first study combining sequence analyses of a substantial EST dataset with microarray expression data of all major life stages (except adult males) for the identification and characterization of putative parasitism-associated proteins in any parasitic nematode. Conclusion We have established an expression atlas for all known H. glycines parasitism genes. Furthermore, in an effort to identify additional H. glycines genes with putative functions in parasitism, we have reduced the currently known 6,860 H

  10. Antagonists of Plant-parasitic Nematodes in Florida Citrus

    PubMed Central

    Walter, David Evans; Kaplan, David T.

    1990-01-01

    In a survey of antagonists of nematodes in 27 citrus groves, each with a history of Tylenchulus semipenetrans infestation, and 17 noncitrus habitats in Florida, approximately 24 species of microbial antagonists capable of attacking vermiform stages of Radopholus citrophilus were recovered. Eleven of these microbes and a species of Pasteuria also were observed attacking vermiform stages of T. semipenetrans. Verticillium chlamydosporium, Paecilomyces lilacinus, P. marquandii, Streptomyces sp., Arthrobotrys oligospora, and Dactylella ellipsospora were found infecting T. semipenetrans egg masses. Two species of nematophagous amoebae, five species of predatory nematodes, and 29 species of nematophagous arthropods also were detected. Nematode-trapping fungi and nematophagous arthropods were common inhabitants of citrus groves with a history of citrus nematode infestation; however, obligate parasites of nematodes were rare. PMID:19287759

  11. Molecular mechanisms of nematode-nematophagous microbe interactions: basis for biological control of plant-parasitic nematodes.

    PubMed

    Li, Juan; Zou, Chenggang; Xu, Jianping; Ji, Xinglai; Niu, Xuemei; Yang, Jinkui; Huang, Xiaowei; Zhang, Ke-Qin

    2015-01-01

    Plant-parasitic nematodes cause significant damage to a broad range of vegetables and agricultural crops throughout the world. As the natural enemies of nematodes, nematophagous microorganisms offer a promising approach to control the nematode pests. Some of these microorganisms produce traps to capture and kill the worms from the outside. Others act as internal parasites to produce toxins and virulence factors to kill the nematodes from within. Understanding the molecular basis of microbe-nematode interactions provides crucial insights for developing effective biological control agents against plant-parasitic nematodes. Here, we review recent advances in our understanding of the interactions between nematodes and nematophagous microorganisms, with a focus on the molecular mechanisms by which nematophagous microorganisms infect nematodes and on the nematode defense against pathogenic attacks. We conclude by discussing several key areas for future research and development, including potential approaches to apply our recent understandings to develop effective biocontrol strategies.

  12. Molecular mechanisms of nematode-nematophagous microbe interactions: basis for biological control of plant-parasitic nematodes.

    PubMed

    Li, Juan; Zou, Chenggang; Xu, Jianping; Ji, Xinglai; Niu, Xuemei; Yang, Jinkui; Huang, Xiaowei; Zhang, Ke-Qin

    2015-01-01

    Plant-parasitic nematodes cause significant damage to a broad range of vegetables and agricultural crops throughout the world. As the natural enemies of nematodes, nematophagous microorganisms offer a promising approach to control the nematode pests. Some of these microorganisms produce traps to capture and kill the worms from the outside. Others act as internal parasites to produce toxins and virulence factors to kill the nematodes from within. Understanding the molecular basis of microbe-nematode interactions provides crucial insights for developing effective biological control agents against plant-parasitic nematodes. Here, we review recent advances in our understanding of the interactions between nematodes and nematophagous microorganisms, with a focus on the molecular mechanisms by which nematophagous microorganisms infect nematodes and on the nematode defense against pathogenic attacks. We conclude by discussing several key areas for future research and development, including potential approaches to apply our recent understandings to develop effective biocontrol strategies. PMID:25938277

  13. Molecular characterization of NAD+-dependent DNA ligase from Wolbachia endosymbiont of lymphatic filarial parasite Brugia malayi.

    PubMed

    Shrivastava, Nidhi; Nag, Jeetendra Kumar; Misra-Bhattacharya, Shailja

    2012-01-01

    The lymphatic filarial parasite, Brugia malayi contains Wolbachia endobacteria that are essential for development, viability and fertility of the parasite. Therefore, wolbachial proteins have been currently seen as the potential antifilarial drug targets. NAD(+)-dependent DNA ligase is characterized as a promising drug target in several organisms due to its crucial, indispensable role in DNA replication, recombination and DNA repair. We report here the cloning, expression and purification of NAD(+)-dependent DNA ligase of Wolbachia endosymbiont of B. malayi (wBm-LigA) for its molecular characterization. wBm-LigA has all the domains that are present in nearly all the eubacterial NAD(+)-dependent DNA ligases such as N-terminal adenylation domain, OB fold, helix-hairpin-helix (HhH) and BRCT domain except zinc-binding tetracysteine domain. The purified recombinant protein (683-amino acid) was found to be biochemically active and was present in its native form as revealed by the circular dichroism and fluorescence spectra. The purified recombinant enzyme was able to catalyze intramolecular strand joining on a nicked DNA as well as intermolecular joining of the cohesive ends of BstEII restricted lamda DNA in an in vitro assay. The enzyme was localized in the various life-stages of B. malayi parasites by immunoblotting and high enzyme expression was observed in Wolbachia within B. malayi microfilariae and female adult parasites along the hypodermal chords and in the gravid portion as evident by the confocal microscopy. Ours is the first report on this enzyme of Wolbachia and these findings would assist in validating the antifilarial drug target potential of wBm-LigA in future studies. PMID:22815933

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

    PubMed

    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. PMID:25910624

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

    PubMed

    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.

  16. Ups and downs of RNA interference in parasitic nematodes.

    PubMed

    Britton, Collette; Samarasinghe, Buddhini; Knox, David P

    2012-09-01

    RNA interference (RNAi) is widely used in Caenorhabiditis elegans to identify essential gene function. In parasitic nematodes RNAi has been reported to result in transcript knockdown of some target genes, but not others, thus limiting its use as a potential functional genomics tool. We recently extended work in Haemonchus contortus to examine why only some genes seem to be susceptible to RNAi and to test RNAi effects in vivo. Here we review our findings, which suggest that site of gene expression influences silencing. This most likely reflects limited uptake of dsRNA from the environment, a phenomenon also observed in other free-living nematodes. We discuss new technologies to improve dsRNA delivery, such as nanoparticles being developed for therapeutic siRNA delivery, and methods to monitor RNAi effects. Alternative approaches will be important in progressing the application of RNAi to identify essential gene function in parasitic nematodes. PMID:21854774

  17. Nematode parasites of waterfowl (Anseriformes) from western United States

    USGS Publications Warehouse

    McDonald, M.E.

    1974-01-01

    Thirty-four species of nematodes were found in 415 Anseriformes (Anatidae) of 27 species; 93.7% of birds over 4 weeks old were infected. Data on prevalence, host specificity, age of host, and geographic distribution are given. Infections were more intense in sick birds and birds in poor physical condition. Accidental or abnormal infection was more likely in sick than in normal birds. From 1 to 13 species of nematodes are reported from each host species, including 118 new host records, 3 nematodes new for North America, and 1 new species. Multiple infections were present in 76.5% of birds parasitized; eight species of nematodes were found in one whistling swan (Olor columbianus).

  18. Resistance of Grape Rootstocks to Plant-parasitic Nematodes

    PubMed Central

    Ferris, H.; Zheng, L.; Walker, M. A.

    2012-01-01

    Candidate grape rootstocks were selected through a rigorous screening program initiated with important sources of resistance to Meloidogyne pathotypes and to Xiphinema index in Muscadinia rotundifolia and Vitis species native to North America. Based on their rooting capability and horticultural characteristics, 200 candidates were selected from 5,000 progeny of multiple crosses between commercial grape rootstocks and wild grape species that exhibited resistance to nematodes. After a 15-year screening process, 13 selections emerged with either almost complete or complete combined resistance to M. incognita Race 3, M. incognita pathotype Harmony C, M. arenaria pathotype Harmony A, and X. index, important nematode pests of grapevines. Durability of this broad resistance was tested by challenging the selections with the target nematodes in combination and with the target nematodes in combinations with species not included in the screening process. Durability of resistance of the candidate rootstocks was also tested by exposure to the nematode communities of infested field soils from different locations. Breadth of resistance was determined on the basis of their host status to non-target nematodes, including Mesocriconema xenoplax, Pratylenchus vulnus, Tylenchulus semipenetrans and Paratylenchus hamatus. After a total of 204 separate trials, the rootstocks were released to the grape industry as UCD GRN1, UCD GRN2, UCD GRN3, UCD GRN4, and UCD GRN5. We provide a compilation of current knowledge of the host status of these five newly released rootstocks and of 27 other rootstock cultivars to plant-parasitic nematodes. PMID:23482972

  19. Adaptive amino acid composition in collagens of parasitic nematodes.

    PubMed

    Hughes, Austin L

    2015-04-01

    Amino acid composition was analyzed in the glycine-rich repeat region of 306 collagens belonging to three major families of collagens from both parasitic and free-living nematodes. The collagens of parasitic species showed a tendency toward decreased usage of the hydrophilic residues A, D, and Q and increased usage of the hydrophobic resides I, L, and M; and this trend was seen in parasitic species of both the order Rhabdita and the order Spirurida. The amino acid composition of collagens of parasitic Rhabdita thus tended to resemble those of Spirurida more than that of free-living Rhabdita, suggesting an association between amino acid composition and a parasitic lifestyle. Computer predictions suggested that the more hydrophobic amino acid composition was associated with a reduction of the propensity towards B-cell epitope formation, suggesting that evasion of host immune responses may be a major selective factor responsible for the parasite-specific trend in collagen amino acid composition.

  20. Mechanisms of molecular mimicry of plant CLE peptide ligands by the parasitic nematode Globodera rostochiensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematodes that parasitize plant roots cause huge economic losses and have few mechanisms for control. Many parasitic nematodes infect plants by reprogramming root development to drive the formation of feeding structures. How nematodes take control of plant development is largely unknown. The CLE ...

  1. Plant-Parasitic Nematodes in Maine Agricultural Soils

    PubMed Central

    Huettel, W N.; Francl, L. J.; Henn, A.; Bourgoin, T.

    1990-01-01

    In a survey of plant-parasitic nematodes associated with agricultural crops in nine Maine counties, 744 soil samples from 26 potential host plants were analyzed between November 1987 and January 1989. The most commonly encountered nematode genus was Pratylenchus, occurring in 85% of the samples from most crops, except blueberries and onions. Pratylenchus penetrans and P. crenatus were found commonly as species mixtures, with P. penetrans composing 40-80% of the mixture. Meloidogyne hapla was encountered in 16% of the samples in four counties, generally in potato rotations. Other nematodes encountered were Aphelenchoides spp., Criconemella curvature, Ditylenchus spp., Helicotylenchus pseudorobustus, H. digonicus, Heterodera trifolii, Paratylenchus projectus, Trichodorus spp., Tylenchorhynchus maximus, and Xiphinema americanum. Potato fields were the most heavily sampled and thus weighted the statewide results. PMID:19287791

  2. Microfluidic bioassay to characterize parasitic nematode phenotype and anthelmintic resistance

    PubMed Central

    CHEN, BAOZHEN; DEUTMEYER, ALEX; CARR, JOHN; ROBERTSON, ALAN P.; MARTIN, RICHARD J.; PANDEY, SANTOSH

    2010-01-01

    SUMMARY With increasing resistance to anti-parasitic drugs, it has become more important to detect and recognize phenotypes of resistant isolates. Molecular methods of detecting resistant isolates are limited at present. Here, we introduce a microfluidic bioassay to measure phenotype using parameters of nematode locomotion. We illustrate the technique on larvae of an animal parasite Oesophagostomum dentatum. Parameters of sinusoidal motion such as propagation velocity, wavelength, wave amplitude, and oscillation frequency depended on the levamisole-sensitivity of the isolate of parasitic nematode. The levamisole-sensitive isolate (SENS) had a mean wave amplitude of 135 μm, which was larger than 123 μm of the levamisole-resistant isolate (LEVR). SENS had a mean wavelength of 373 μm, which was less than 393 μm of LEVR. The mean propagation velocity of SENS, 149 μm s−1, was similar to LEVR, 143 μm s−1. The propagation velocity of the isolates was inhibited by levamisole in a concentration-dependent manner above 0.5 μM. The EC50 for SENS was 3 μM and the EC50 for LEVR was 10 μM. This microfluidic technology advances present-day nematode migration assays and provides a better quantification and increased drug sensitivity. It is anticipated that the bioassay will facilitate study of resistance to other anthelmintic drugs that affect locomotion. PMID:20663251

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

    PubMed

    Villemant, Claire; Zuccon, Dario; Rome, Quentin; Muller, Franck; Poinar, George O; Justine, Jean-Lou

    2015-01-01

    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. PMID:26038716

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

    PubMed Central

    Zuccon, Dario; Rome, Quentin; Muller, Franck; Poinar Jr, George O.; Justine, Jean-Lou

    2015-01-01

    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. PMID:26038716

  5. Gedunin and photogedunin of Xylocarpus granatum possess antifilarial activity against human lymphatic filarial parasite Brugia malayi in experimental rodent host.

    PubMed

    Misra, Sweta; Verma, Meenakshi; Mishra, Sunil Kumar; Srivastava, Shishir; Lakshmi, Vijai; Misra-Bhattacharya, Shailja

    2011-11-01

    The present study is aimed to evaluate antifilarial activity of Xylocarpus granatum (fruit from Andaman) against human lymphatic filarial parasite Brugia malayi in vivo. The in vitro antifilarial activity has already been reported earlier for this mangrove plant which has traditionally been used against several ailments. Aqueous ethanolic crude extract, four fractions (ethyl acetate fraction, n-butanol fraction, water-soluble fraction and water-insoluble fraction) and pure molecule/s of X. granatum (fruit) were tested in vitro on adult worms and microfilariae (mf) of B. malayi and the active samples were further evaluated in vivo in B. malayi (intraperitoneally) i.p. transplanted in the jird model (Meriones unguiculatus) and Mastomys coucha subcutaneously infected with infective larvae (L3). The crude aqueous ethanolic extract was active in vitro (IC50: adult = 15.46 μg/ml; mf = 13.17 μg/ml) and demonstrated 52.8% and 62.7% adulticidal and embryostatic effect on B. malayi, respectively, in Mastomys at a dose of 5 × 50 mg/kg by oral route. The antifilarial activity was primarily localized in the ethyl acetate-soluble fraction which revealed IC50 of 8.5 and 6.9 μg/ml in adult and mf, respectively. This fraction possessed moderate adulticidal and embryostatic action in vivo in Mastomys. Out of eight pure molecules isolated from the active fraction, two compounds gedunin (IC50 = 0.239 μg/ml, CC50 = 212.5 μg/ml, SI = 889.1) and photogedunin (IC50 = 0.213 μg/ml, CC50 = 262.3 μg/ml, SI = 1231.4) at 5 × 100 mg/kg by subcutaneous route revealed excellent adulticidal efficacy resulting in to the death of 80% and 70% transplanted adult B. malayi in the peritoneal cavity of jirds respectively in addition to noticeable microfilaricidalo action on the day of autopsy. The findings reveal that the extract from the fruit X. granatum contains promising in vitro and in vivo antifilarial activity against human lymphatic filarial parasite B. malayi which could be attributed to

  6. Survey of Plant-parasitic Nematodes in Missouri Cotton Fields

    PubMed Central

    Wrather, J. A.; Niblack, T. L.; Milam, M. R.

    1992-01-01

    During September 1990, 30 cotton fields in each of three Missouri counties were surveyed for plant-parasitic nematodes. Soil samples for nematode analysis consisted of a composite of 20 cores collected in a zig-zag pattern within a 1-ha block in each field. Cores were taken from within weed-free cotton rows. Nine genera of plant-parasitic nematodes were found (Rotylenchulus, Helicotylenchus, Hoplolaimus, Meloidogyne, Paratylenchus, Pratylenchus, Tylenchorhynchus, Heterodera, and Trichodorus), and five species were identified: Meloidogyne incognita, Rotylenchulus reniformis, Hoplolaimus galeatus, Pratylenchus vulnus, and P. scribneri. This is the first report of R. reniformis, H. galeatus, P. vulnus, and P. scribneri in Missouri cotton fields and the first report of R. reniformis and P. vulnus in Missouri. The known cotton pathogens M. incognita, R. reniformis, and H. galeatus were found in 30%, 3%, and 2% of the fields sampled, respectively. The correlation between sand content of the soil sample and the number of vermiform M. incognita in the sample was not significant, with r² = 0.13. Select fields where H. galeatus and R. reniformis were found in 1990 were sampled more intensely in 1991. The 1-ha block sampled in 1990 was sampled in 1991, along with three other 1-ha blocks uniformly distributed within the field. In addition, a 1-ha block was sampled in each of eight nearby fields, within 2 km of the first field. The nine plant-parasitic nematode genera identified in the 1990 survey were observed again in 1991. Within-field distribution of M. incognita, R. reniformis, and H. galeatus was not uniform. When M. incognita, R. reniformis, or H. galeatus were present in a field, the same species was found in 38%, 25%, or 50% of nearby fields, respectively. PMID:19283062

  7. Arabidopsis small RNAs and their targets during cyst nematode parasitism.

    PubMed

    Hewezi, Tarek; Howe, Peter; Maier, Tom R; Baum, Thomas J

    2008-12-01

    Plant-parasitic cyst nematodes induce the formation of specialized feeding cells in infected roots, which involves plant developmental processes that have been shown to be influenced by microRNAs (miRNAs) and other small RNAs. This observation provided the foundation to investigate the potential involvement of small RNAs in plant-cyst nematode interactions. First, we examined the susceptibilities of Arabidopsis DICER-like (dcl) and RNA-dependent RNA polymerase (rdr) mutants to the sugar beet cyst nematode Heterodera schachtii. The examined mutants exhibited a trend of decreased susceptibility, suggesting a role of small RNAs mediating gene regulation processes during the plant-nematode interaction. Second, we generated two small RNA libraries from aseptic Arabidopsis roots harvested at 4 and 7 days after infection with surface-sterilized H. schachtii. Sequences of known miRNAs as well as novel small interfering (si)RNAs were identified. Following this discovery, we used real-time reverse-transcriptase polymerase chain reaction to quantify a total of 15 Arabidopsis transcripts that are known targets of six of the different miRNA families found in our study (miR160, miR164, miR167, miR171, miR396, and miR398) in inoculated and noninoculated Arabidopsis roots. Our analyses showed mostly negative correlations between miRNA accumulation and target gene mRNA abundance, suggesting regulatory roles of these miRNAs during parasitism. Also, we identified a total of 125 non-miRNA siRNAs. Some of these siRNAs perfectly complement protein-coding mRNAs or match transposon or retrotransposon sequences in sense or antisense orientations. We further quantified a group of siRNAs in H. schachtii-inoculated roots. The examined siRNAs exhibited distinct expression patterns in infected and noninfected roots, providing additional evidence for the implication of small RNAs in cyst nematode parasitism. These data lay the foundation for detailed analyses of the functions of small RNAs

  8. Limiting opportunities for cheating stabilizes virulence in insect parasitic nematodes.

    PubMed

    Shapiro-Ilan, David; Raymond, Ben

    2016-03-01

    Cooperative secretion of virulence factors by pathogens can lead to social conflict when cheating mutants exploit collective secretion, but do not contribute to it. If cheats outcompete cooperators within hosts, this can cause loss of virulence. Insect parasitic nematodes are important biocontrol tools that secrete a range of significant virulence factors. Critically, effective nematodes are hard to maintain without live passage, which can lead to virulence attenuation. Using experimental evolution, we tested whether social cheating might explain unstable virulence in the nematode Heterorhabditis floridensis by manipulating relatedness via multiplicity of infection (MOI), and the scale of competition. Passage at high MOI, which should reduce relatedness, led to loss of fitness: virulence and reproductive rate declined together and all eight independent lines suffered premature extinction. As theory predicts, relatedness treatments had more impact under stronger global competition. In contrast, low MOI passage led to more stable virulence and increased reproduction. Moreover, low MOI lineages showed a trade-off between virulence and reproduction, particularly for lines under stronger between-host competition. Overall, this study indicates that evolution of virulence theory is valuable for the culture of biocontrol agents: effective nematodes can be improved and maintained if passage methods mitigate possible social conflicts. PMID:26989437

  9. Limiting opportunities for cheating stabilizes virulence in insect parasitic nematodes.

    PubMed

    Shapiro-Ilan, David; Raymond, Ben

    2016-03-01

    Cooperative secretion of virulence factors by pathogens can lead to social conflict when cheating mutants exploit collective secretion, but do not contribute to it. If cheats outcompete cooperators within hosts, this can cause loss of virulence. Insect parasitic nematodes are important biocontrol tools that secrete a range of significant virulence factors. Critically, effective nematodes are hard to maintain without live passage, which can lead to virulence attenuation. Using experimental evolution, we tested whether social cheating might explain unstable virulence in the nematode Heterorhabditis floridensis by manipulating relatedness via multiplicity of infection (MOI), and the scale of competition. Passage at high MOI, which should reduce relatedness, led to loss of fitness: virulence and reproductive rate declined together and all eight independent lines suffered premature extinction. As theory predicts, relatedness treatments had more impact under stronger global competition. In contrast, low MOI passage led to more stable virulence and increased reproduction. Moreover, low MOI lineages showed a trade-off between virulence and reproduction, particularly for lines under stronger between-host competition. Overall, this study indicates that evolution of virulence theory is valuable for the culture of biocontrol agents: effective nematodes can be improved and maintained if passage methods mitigate possible social conflicts.

  10. Parasite-induced aposematism” protects entomopathogenic nematode parasites against invertebrate enemies

    PubMed Central

    Fenton, Andy; Speed, Michael P.

    2016-01-01

    Aposematism is a well-known strategy in which prey defend themselves from predation by pairing defenses such as toxins, with warning signals that are often visually conspicuous color patterns. Here, we examine the possibility that aposematism can be induced in a host by colonies of infectious parasites in order to protect the parasites from the consequences of attacks on the host. Earlier studies show that avian predators are reluctant to feed on carcasses of host prey that are infected with the entomopathogenic nematode, Heterorhabditis bacteriophora. As the age of infection increases, the parasites kill and preserve the host and subsequently cause its color to change, becoming bright pink then red. Nematode colonies in dead hosts may also be vulnerable, however, to nocturnally active foragers that do not use vision in prey detection. Here, then we test a novel hypothesis that the nematode parasites also produce a warning odor, which functions to repel nocturnally active predators (in this case, the beetle Pterostichus madidus). We show that beetles decrease their feeding on infected insect prey as the age of infection increases and that olfactory cues associated with the infections are effective mechanisms for deterring beetle predation, even at very early stages of infection. We propose that “parasite-induced aposematism” from the nematodes serves to replace the antipredator defenses of the recently killed host. Because sessile carcasses are exposed to a greater range of predators than the live hosts, several alternative defense mechanisms are required to protect the colony, hence aposematic signals are likely diverse in such “parasite-induced aposematism.” PMID:27004015

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

    PubMed

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

    2008-12-01

    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.

  12. Chemical ecology and isolation of biologically active compounds from parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root knot nematodes (Meloidogyne spp) are possibly the economically most important and best-studied species of plant parasitic nematodes. However, for Meloidogyne spp and the intensely studied nematode, Caenorhabditis elegans, very little is known about signaling within and in-between species. It h...

  13. Large Particle Sorting to Isolate Live Parasitic Nematode Eggs.

    PubMed

    Schmidt, Alfonso; Bouchery, Tiffany; Le Gros, Graham; Price, Kylie M

    2016-01-01

    Traditional jet-in-air cell sorters have been designed and optimized to isolate small particles such as mammalian lymphocytes with an average diameter of 10 μm. We discuss the practical considerations of setting up a conventional jet-in-air cell sorter, using a 200-μm nozzle, to isolate the large parasitic nematode eggs of Nippostrongylus brasiliensis, with a maximum size of 60 μm. The eggs were separated based on light scattering properties, no fluorescent dye or molecule was required. PMID:27037578

  14. Guidelines for Introducing Beneficial Insect-parasitic Nematodes into the United States

    PubMed Central

    Nickle, W. R.; Drea, J. J.; Coulson, J. R.

    1988-01-01

    Guidelines are suggested to implement the introduction of beneficial insect-parasitic nematodes into the United States from abroad. These suggestions result from experiences and research with these and other biological control agents and from the current need for procedures to import nematodes. Subjects considered are need to import, foreign exploration, taxonomy, shipment, quarantine facilities, permits, host range tests, release, and documentation. Nematodes covered under these suggested guidelines include entomopathogenic species of mermithids, sphaerulariids, aphelenchids, steinernematids, and heterorhabditids. Host specificity and safety tests are discussed. Concern over the possible concomitant introduction of plant-parasitic nematodes, insects, or other pests is expressed. Current information on the treatment of insect-parasitic nematodes by the Environmental Protection Agency and USDA's Animal and Plant Health Inspection Service is presented. These suggested guidelines are presented to stimulate the development of workable protocols for safe introduction of beneficial insect-parasitic nematodes into the United States from aboard. PMID:19290303

  15. Survey of gastrointestinal nematode parasites in Saskatchewan beef herds

    PubMed Central

    Jelinski, Murray; Lanigan, Emily; Gilleard, John; Waldner, Cheryl; Royan, Grant

    2016-01-01

    A survey of gastrointestinal parasites in Saskatchewan beef herds was conducted over the summer of 2014. Fecal samples were collected on 3 occasions during the summer grazing season from beef cows and calves from 14 herds. The mean number of strongylid eggs per gram of feces recovered from calves increased 9-fold (95% CI: 4.5 to 18) over the summer period, while egg counts in the cows remained constant over the same period. The prevalence and infection intensities of gastrointestinal nematode parasites in cow-calf herds in Saskatchewan were comparable to what is seen in cattle grazing in the northern regions of the United States and for which anthelmintic treatments have resulted in positive production benefits. PMID:26834267

  16. Survey of gastrointestinal nematode parasites in Saskatchewan beef herds.

    PubMed

    Jelinski, Murray; Lanigan, Emily; Gilleard, John; Waldner, Cheryl; Royan, Grant

    2016-02-01

    A survey of gastrointestinal parasites in Saskatchewan beef herds was conducted over the summer of 2014. Fecal samples were collected on 3 occasions during the summer grazing season from beef cows and calves from 14 herds. The mean number of strongylid eggs per gram of feces recovered from calves increased 9-fold (95% CI: 4.5 to 18) over the summer period, while egg counts in the cows remained constant over the same period. The prevalence and infection intensities of gastrointestinal nematode parasites in cow-calf herds in Saskatchewan were comparable to what is seen in cattle grazing in the northern regions of the United States and for which anthelmintic treatments have resulted in positive production benefits.

  17. Comparative Analysis of the Secretome from a Model Filarial Nematode (Litomosoides sigmodontis) Reveals Maximal Diversity in Gravid Female Parasites*

    PubMed Central

    Armstrong, Stuart D.; Babayan, Simon A.; Lhermitte-Vallarino, Nathaly; Gray, Nick; Xia, Dong; Martin, Coralie; Kumar, Sujai; Taylor, David W.; Blaxter, Mark L.; Wastling, Jonathan M.; Makepeace, Benjamin L.

    2014-01-01

    Filarial nematodes (superfamily Filarioidea) are responsible for an annual global health burden of ∼6.3 million disability-adjusted life-years, which represents the greatest single component of morbidity attributable to helminths affecting humans. No vaccine exists for the major filarial diseases, lymphatic filariasis and onchocerciasis; in part because research on protective immunity against filariae has been constrained by the inability of the human-parasitic species to complete their lifecycles in laboratory mice. However, the rodent filaria Litomosoides sigmodontis has become a popular experimental model, as BALB/c mice are fully permissive for its development and reproduction. Here, we provide a comprehensive analysis of excretory-secretory products from L. sigmodontis across five lifecycle stages and identifications of host proteins associated with first-stage larvae (microfilariae) in the blood. Applying intensity-based quantification, we determined the abundance of 302 unique excretory-secretory proteins, of which 64.6% were present in quantifiable amounts only from gravid adult female nematodes. This lifecycle stage, together with immature microfilariae, released four proteins that have not previously been evaluated as vaccine candidates: a predicted 28.5 kDa filaria-specific protein, a zonadhesin and SCO-spondin-like protein, a vitellogenin, and a protein containing six metridin-like ShK toxin domains. Female nematodes also released two proteins derived from the obligate Wolbachia symbiont. Notably, excretory-secretory products from all parasite stages contained several uncharacterized members of the transthyretin-like protein family. Furthermore, biotin labeling revealed that redox proteins and enzymes involved in purinergic signaling were enriched on the adult nematode cuticle. Comparison of the L. sigmodontis adult secretome with that of the human-infective filarial nematode Brugia malayi (reported previously in three independent published studies

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

    PubMed

    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.

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

    PubMed

    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. PMID:27466450

  20. Exploring the Host Parasitism of the Migratory Plant-Parasitic Nematode Ditylenchus destuctor by Expressed Sequence Tags Analysis

    PubMed Central

    Peng, Huan; Gao, Bing-li; Kong, Ling-an; Yu, Qing; Huang, Wen-kun; He, Xu-feng; Long, Hai-bo; Peng, De-liang

    2013-01-01

    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 those of sedentary

  1. Parasitic success without sex – the nematode experience.

    PubMed

    Castagnone-Sereno, P; Danchin, E G J

    2014-07-01

    Asexual reproduction is usually considered as an evolutionary dead end, and difficulties for asexual lineages to adapt to a fluctuating environment are anticipated due to the lack of sufficient genetic plasticity. Yet, unlike their sexual congeners, mitotic parthenogenetic root-knot nematode species, Meloidogyne spp., are remarkably widespread and polyphagous, with the ability to parasitize most flowering plants. Although this may reflect in part the short-term stability of agricultural environments, the extreme parasitic success of these clonal species points them as an outstanding evolutionary paradox regarding current theories on the benefits of sex. The discovery that most of the genome of the clonal species M. incognita is composed of pairs of homologous but divergent segments that have presumably been evolving independently in the absence of sexual recombination has shed new light on this evolutionary paradox. Together with recent studies on other biological systems, including the closely related sexual species M. hapla and the ancient asexual bdelloid rotifers, this observation suggests that functional innovation could emerge from such a peculiar genome architecture, which may in turn account for the extreme adaptive capacities of these asexual parasites. Additionally, the higher proportion of transposable elements in M. incognita compared to M. hapla and other nematodes may also be responsible in part for genome plasticity in the absence of sexual reproduction. We foresee that ongoing sequencing efforts should lead soon to a genomic framework involving genetically diverse Meloidogyne species with various different reproductive modes. This will undoubtedly promote the entire genus as a unique and valuable model system to help deciphering the evolution of asexual reproduction in eukaryotes.

  2. Alternatives to Fenamiphos for Management of Plant-Parasitic Nematodes on Bermudagrass

    PubMed Central

    Crow, W. T.

    2005-01-01

    Plant-parasitic nematodes can be very damaging to turfgrasses. The projected cancellation of the registration for fenamiphos in the near future has generated a great deal of interest in identifying acceptable alternative nematode management tactics for use on turfgrasses. Two field experiments were conducted to evaluate the effectiveness of repeated applications of several commercially available nematicides and root biostimulants for reducing population densities of plant-parasitic nematodes and (or) promoting health of bermudagrass in nematode-infested soil. One experimental site was infested with Hoplolaimus galeatus and Trichodorus obtusus, the second with Belonolaimus longicaudatus. In both trials, none of the experimental treatments reduced population densities (P ≤ 0.1) of plant-parasitic nematodes, or consistently promoted turf visual performance or turf root production. Nematologists with responsibility to advise turf managers regarding nematode management should thoroughly investigate the validity of product claims before advising clientele in their use. PMID:19262894

  3. Overview of Organic Amendments for Management of Plant-Parasitic Nematodes, with Case Studies from Florida

    PubMed Central

    2011-01-01

    Organic amendments have been widely used for management of plant-parasitic nematodes. Relatively rapid declines in nematode population levels may occur when decomposing materials release toxic compounds, while longer-term effects might include increases in nematode antagonists. Improved crop nutrition and plant growth following amendment use may lead to tolerance of plant-parasitic nematodes. Results depend on a great variety of factors such as material used, processing/composting of material, application rate, test arena, crop rotation and agronomic practices, soil type, climate, and other environmental factors. Reasons for variable performance and interpretation of results from amendment studies are discussed. Case studies of amendments for nematode management are reviewed from Florida, where composts and crop residues are the most frequently used amendments. Plant growth was often improved by amendment application, free-living nematodes (especially bacterivores) were often stimulated, but suppression of plant-parasitic nematodes was inconsistent. Amendments were generally not as effective as soil fumigation with methyl bromide for managing root-knot nematodes (Meloidogyne spp.), and often population levels or galling of root-knot nematodes in amended plots did not differ from those in non-amended control plots. While amendments may improve plant growth and stimulate soil food webs, additional study and testing are needed before they could be used reliably for management of plant-parasitic nematodes under Florida conditions. PMID:22791915

  4. Subtilisin-like proteases in nematodes.

    PubMed

    Poole, Catherine B; Jin, Jingmin; McReynolds, Larry A

    2007-09-01

    Cleavage by subtilisin-like proteases (subtilases) is an essential step in post-translational processing of proteins found in organisms ranging from yeast to mammals. Our knowledge of the diversity of this protease family in nematodes is aided by the rapid increase in sequence information, especially from the Brugia malayi genome project. Genetic studies of the subtilases in Caenorhabitis elegans give valuable insight into the biological function of these proteases in other nematode species. In this review, we focus on the subtilases in filarial nematodes as well as other parasitic and free-living nematodes in comparison to what is known in C. elegans. Topics to be addressed include expansion and diversity of the subtilase gene family during evolution, enhanced complexity created by alternative RNA splicing, molecular and biochemical characterization of the different subtilases and the challenges of designing subtilase-specific inhibitors for parasitic nematodes. PMID:17570539

  5. The Genomic Basis of Parasitism in the Strongyloides Clade of Nematodes

    PubMed Central

    Hunt, Vicky L.; Tsai, Isheng J.; Coghlan, Avril; Reid, Adam J.; Holroyd, Nancy; Foth, Bernardo J.; Tracey, Alan; Cotton, James A.; Stanley, Eleanor J.; Beasley, Helen; Bennett, Hayley M.; Brooks, Karen; Harsha, Bhavana; Kajitani, Rei; Kulkarni, Arpita; Harbecke, Dorothee; Nagayasu, Eiji; Nichol, Sarah; Ogura, Yoshitoshi; Quail, Michael A.; Randle, Nadine; Xia, Dong; Brattig, Norbert W.; Soblik, Hanns; Ribeiro, Diogo M.; Sanchez-Flores, Alejandro; Hayashi, Tetsuya; Itoh, Takehiko; Denver, Dee R.; Grant, Warwick; Stoltzfus, Jonathan D.; Lok, James B.; Murayama, Haruhiko; Wastling, Jonathan; Streit, Adrian; Kikuchi, Taisei; Viney, Mark; Berriman, Matthew

    2016-01-01

    Soil transmitted nematodes, including Strongyloides, cause one of the most prevalent Neglected Tropical Diseases. Here we compare the genomes of four Strongyloides spp., including the human pathogen S. stercoralis, and their close relatives that are facultatively parasitic (Parastrongyloides trichosuri) and free-living (Rhabditophanes sp). A significant paralogous expansion of key gene families – astacin-like and SCP/TAPS coding gene families – is associated with the evolution of parasitism in this clade. Exploiting the unique Strongyloides life cycle we compare the transcriptome of its parasitic and free-living stages and find that these same genes are upregulated in the parasitic stages, underscoring their role in nematode parasitism. PMID:26829753

  6. Disorganized muscle protein-1 (DIM-1) of filarial parasite Brugia malayi: cDNA cloning, expression, purification, structural modeling and its potential as vaccine candidate for human filarial infection.

    PubMed

    Kushwaha, Vikas; Kumar, Vikash; Verma, Shiv K; Sharma, Rolee; Siddiqi, M I; Murthy, P K

    2014-03-26

    We have recently identified disorganized muscle protein-1 (DIM-1) in one of the proinflammatory fractions of the human filaria Brugia malayi adult worm. The present study was undertaken to characterize B. malayi DIM-1 (DIM-1bm) and explore its vaccine potential. In this study we cloned and expressed the DIM-1bm gene, investigated its sequence homology with other nematodes, constructed in silico structural model, purified the recombinant DIM-1bm (rDIM-1bm) protein, and studied the effect of immunization with rDIM-1bm on the establishment of B. malayi infection in Mastomys coucha. DIM-1bm showed similarity with DIM-1 of Caenorhabditis elegans, Ascaris suum and Loa loa. Structural modeling revealed three immunoglobulin domains in DIM-1bm indicating that it is a member of immunoglobulin superfamily (IgSF) and 'blastn' results showed that DIM-1bm coding sequence (CDS) have almost no homology with human and mouse nucleotide sequences. Immunization with rDIM-1bm partially protected M. coucha against establishment of infection as inferred by a low recovery of microfilariae (37-64%) and parasite burden (∼50%). The enhanced activity of macrophages, and IFN-γ and NO responses, and elevated levels of specific IgG, IgG1, IgG2a and IgG2b correlated with parasitological findings. This is the first report on cloning, expression, structural modeling and purification of rDIM-1bm and its ability to partially prevent establishment of B. malayi infection. DIM-1bm's almost complete lack of homology with the human counterpart makes it an attractive protein for exploring its vaccine potential. PMID:24513011

  7. Ancient horizontal transfers of retrotransposons between birds and ancestors of human pathogenic nematodes.

    PubMed

    Suh, Alexander; Witt, Christopher C; Menger, Juliana; Sadanandan, Keren R; Podsiadlowski, Lars; Gerth, Michael; Weigert, Anne; McGuire, Jimmy A; Mudge, Joann; Edwards, Scott V; Rheindt, Frank E

    2016-01-01

    Parasite host switches may trigger disease emergence, but prehistoric host ranges are often unknowable. Lymphatic filariasis and loiasis are major human diseases caused by the insect-borne filarial nematodes Brugia, Wuchereria and Loa. Here we show that the genomes of these nematodes and seven tropical bird lineages exclusively share a novel retrotransposon, AviRTE, resulting from horizontal transfer (HT). AviRTE subfamilies exhibit 83-99% nucleotide identity between genomes, and their phylogenetic distribution, paleobiogeography and invasion times suggest that HTs involved filarial nematodes. The HTs between bird and nematode genomes took place in two pantropical waves, >25-22 million years ago (Myr ago) involving the Brugia/Wuchereria lineage and >20-17 Myr ago involving the Loa lineage. Contrary to the expectation from the mammal-dominated host range of filarial nematodes, we hypothesize that these major human pathogens may have independently evolved from bird endoparasites that formerly infected the global breadth of avian biodiversity. PMID:27097561

  8. Ancient horizontal transfers of retrotransposons between birds and ancestors of human pathogenic nematodes

    PubMed Central

    Suh, Alexander; Witt, Christopher C.; Menger, Juliana; Sadanandan, Keren R.; Podsiadlowski, Lars; Gerth, Michael; Weigert, Anne; McGuire, Jimmy A.; Mudge, Joann; Edwards, Scott V.; Rheindt, Frank E.

    2016-01-01

    Parasite host switches may trigger disease emergence, but prehistoric host ranges are often unknowable. Lymphatic filariasis and loiasis are major human diseases caused by the insect-borne filarial nematodes Brugia, Wuchereria and Loa. Here we show that the genomes of these nematodes and seven tropical bird lineages exclusively share a novel retrotransposon, AviRTE, resulting from horizontal transfer (HT). AviRTE subfamilies exhibit 83–99% nucleotide identity between genomes, and their phylogenetic distribution, paleobiogeography and invasion times suggest that HTs involved filarial nematodes. The HTs between bird and nematode genomes took place in two pantropical waves, >25–22 million years ago (Myr ago) involving the Brugia/Wuchereria lineage and >20–17 Myr ago involving the Loa lineage. Contrary to the expectation from the mammal-dominated host range of filarial nematodes, we hypothesize that these major human pathogens may have independently evolved from bird endoparasites that formerly infected the global breadth of avian biodiversity. PMID:27097561

  9. Ancient horizontal transfers of retrotransposons between birds and ancestors of human pathogenic nematodes.

    PubMed

    Suh, Alexander; Witt, Christopher C; Menger, Juliana; Sadanandan, Keren R; Podsiadlowski, Lars; Gerth, Michael; Weigert, Anne; McGuire, Jimmy A; Mudge, Joann; Edwards, Scott V; Rheindt, Frank E

    2016-04-21

    Parasite host switches may trigger disease emergence, but prehistoric host ranges are often unknowable. Lymphatic filariasis and loiasis are major human diseases caused by the insect-borne filarial nematodes Brugia, Wuchereria and Loa. Here we show that the genomes of these nematodes and seven tropical bird lineages exclusively share a novel retrotransposon, AviRTE, resulting from horizontal transfer (HT). AviRTE subfamilies exhibit 83-99% nucleotide identity between genomes, and their phylogenetic distribution, paleobiogeography and invasion times suggest that HTs involved filarial nematodes. The HTs between bird and nematode genomes took place in two pantropical waves, >25-22 million years ago (Myr ago) involving the Brugia/Wuchereria lineage and >20-17 Myr ago involving the Loa lineage. Contrary to the expectation from the mammal-dominated host range of filarial nematodes, we hypothesize that these major human pathogens may have independently evolved from bird endoparasites that formerly infected the global breadth of avian biodiversity.

  10. Spatial distribution of plant-parasitic nematodes in semi-arid Vitis vinifera vineyards in Washington

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The most commonly encountered plant-parasitic nematodes in eastern Washington Vitis vinifera vineyards are Meloidogyne hapla, Mesocriconema xenoplax, Pratylenchus spp., Xiphinema americanum, and Paratylenchus sp.; however, little is known about their distribution in the soil profile. The vertical an...

  11. Transcript Analysis of Parasitic Females of the Sedentary Semi-Endoparasitic Nematode Rotylenchulus reniformis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The reniform nematode, Rotylenchulus reniformis Linford & Oliveira, is a sedentary semi-endoparasitic roundworm that infects the roots of many economically important plant species. Engineered resistance to plant-parasitic nematodes (PPNs) via RNA-interference (RNAi) has shown promise in providing h...

  12. The plant-parasitic nematode collections of RRIP: The realization of an ISTC project

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant-parasitic nematodes are important pests of agricultural and wild plants throughout Russia and the world. The best strategy for management of nematode damage is an integrated approach to the problem: i.e., the use of agrotechnological approaches (crop rotation, soil amendments, etc.), reasonabl...

  13. Gastrointestinal nematode species diversity in Soay sheep kept in a natural environment without active parasite control.

    PubMed

    Sinclair, Rona; Melville, Lynsey; Sargison, Fiona; Kenyon, Fiona; Nussey, Dan; Watt, Kathryn; Sargison, Neil

    2016-08-30

    Molecular methods based on ITS2 sequence analysis were used to identify strongylid parasites and describe their diversity in a management intervention and anthelmintic drug treatment-free sheep flock. Fourteen different nematode parasite species were identified in the flock and the results showed a greater level of nematode species diversity than is normally reported in managed farmed flocks, with the presence of parasites such as Bunostomum trigonocephalum, Ostertagia leptospicularis, Spiculopteragia houdemeri and Trichostrongylus retortaeformis that are considered to be absent or rare in sheep kept in comparable localities. The implied prevalences of Haemonchus contortus in lambs, and of Trichostrongylus axei in lambs, ewes and rams, were higher than those in farmed sheep kept in similar regions, while those of Teladorsagia circumcincta and Trichostrongylus vitrinus were lower. Comparison of the patterns of nematode parasite infection between the summer and autumn sampling periods showed differences from the scenarios that are commonplace in comparable managed flocks; with T. vitrinus burdens of the lambs being higher in the summer than in the winter, and Oesophagostomum venulosum being the predominant nematode species in the adult sheep during the summer, while more-or-less absent from these groups during the winter. Rams played an important role in the epidemiology of certain parasitic nematode species. The relatively non-pathogenic O. venulosum was the only parasitic nematode species to predominate in any group during the study. This preliminary characterisation of the nematode parasite burdens of sheep extensively grazed on diverse unimproved pastures will aid in the understanding of the parasitological consequences of intensive grazing management and of the manner in which modern agriculture upsets the equilibrium between parasites and their hosts. These factors must be accounted for when defining the concept of sustainable parasite control and informing

  14. Gastrointestinal nematode species diversity in Soay sheep kept in a natural environment without active parasite control.

    PubMed

    Sinclair, Rona; Melville, Lynsey; Sargison, Fiona; Kenyon, Fiona; Nussey, Dan; Watt, Kathryn; Sargison, Neil

    2016-08-30

    Molecular methods based on ITS2 sequence analysis were used to identify strongylid parasites and describe their diversity in a management intervention and anthelmintic drug treatment-free sheep flock. Fourteen different nematode parasite species were identified in the flock and the results showed a greater level of nematode species diversity than is normally reported in managed farmed flocks, with the presence of parasites such as Bunostomum trigonocephalum, Ostertagia leptospicularis, Spiculopteragia houdemeri and Trichostrongylus retortaeformis that are considered to be absent or rare in sheep kept in comparable localities. The implied prevalences of Haemonchus contortus in lambs, and of Trichostrongylus axei in lambs, ewes and rams, were higher than those in farmed sheep kept in similar regions, while those of Teladorsagia circumcincta and Trichostrongylus vitrinus were lower. Comparison of the patterns of nematode parasite infection between the summer and autumn sampling periods showed differences from the scenarios that are commonplace in comparable managed flocks; with T. vitrinus burdens of the lambs being higher in the summer than in the winter, and Oesophagostomum venulosum being the predominant nematode species in the adult sheep during the summer, while more-or-less absent from these groups during the winter. Rams played an important role in the epidemiology of certain parasitic nematode species. The relatively non-pathogenic O. venulosum was the only parasitic nematode species to predominate in any group during the study. This preliminary characterisation of the nematode parasite burdens of sheep extensively grazed on diverse unimproved pastures will aid in the understanding of the parasitological consequences of intensive grazing management and of the manner in which modern agriculture upsets the equilibrium between parasites and their hosts. These factors must be accounted for when defining the concept of sustainable parasite control and informing

  15. Biotechnological application of functional genomics towards plant-parasitic nematode control.

    PubMed

    Li, Jiarui; Todd, Timothy C; Lee, Junghoon; Trick, Harold N

    2011-12-01

    Plant-parasitic nematodes are primary biotic factors limiting the crop production. Current nematode control strategies include nematicides, crop rotation and resistant cultivars, but each has serious limitations. RNA interference (RNAi) represents a major breakthrough in the application of functional genomics for plant-parasitic nematode control. RNAi-induced suppression of numerous genes essential for nematode development, reproduction or parasitism has been demonstrated, highlighting the considerable potential for using this strategy to control damaging pest populations. In an effort to find more suitable and effective gene targets for silencing, researchers are employing functional genomics methodologies, including genome sequencing and transcriptome profiling. Microarrays have been used for studying the interactions between nematodes and plant roots and to measure both plants and nematodes transcripts. Furthermore, laser capture microdissection has been applied for the precise dissection of nematode feeding sites (syncytia) to allow the study of gene expression specifically in syncytia. In the near future, small RNA sequencing techniques will provide more direct information for elucidating small RNA regulatory mechanisms in plants and specific gene silencing using artificial microRNAs should further improve the potential of targeted gene silencing as a strategy for nematode management.

  16. Bioinformatic exploration of RIO protein kinases of parasitic and free-living nematodes.

    PubMed

    Breugelmans, Bert; Jex, Aaron R; Korhonen, Pasi K; Mangiola, Stefano; Young, Neil D; Sternberg, Paul W; Boag, Peter R; Hofmann, Andreas; Gasser, Robin B

    2014-10-01

    Despite right open reading frame kinases (RIOKs) being essential for life, their functions, substrates and cellular pathways remain enigmatic. In the present study, gene structures were characterised for 26 RIOKs from draft genomes of parasitic and free-living nematodes. RNA-seq transcription profiles of riok genes were investigated for selected parasitic nematodes and showed that these kinases are transcribed in developmental stages that infect their mammalian host. Three-dimensional structural models of Caenorhabditis elegans RIOKs were predicted, and elucidated functional domains and conserved regions in nematode homologs. These findings provide prospects for functional studies of riok genes in C. elegans, and an opportunity for the design and validation of nematode-specific inhibitors of these enzymes in socioeconomic parasitic worms.

  17. AMF-induced biocontrol against plant parasitic nematodes in Musa sp.: a systemic effect.

    PubMed

    Elsen, A; Gervacio, D; Swennen, R; De Waele, D

    2008-07-01

    Although mycorrhizal colonization provides a bioprotectional effect against a broad range of soil-borne pathogens, including plant parasitic nematodes, the commercial use of arbuscular mycorrhizal fungi (AMF) as biocontrol agents is still in its infancy. One of the main reasons is the poor understanding of the modes of action. Most AMF mode of action studies focused on AMF-bacterial/fungal pathogens. Only few studies so far examined AMF-plant parasitic nematode interactions. Therefore, the aim of the study was to determine whether the AMF Glomus intraradices was able to incite systemic resistance in banana plants towards Radopholus similis and Pratylenchus coffeae, two plant parasitic nematodes using a split-root compartmental set-up. The AMF reduced both nematode species by more than 50%, even when the AMF and the plant parasitic nematodes were spatially separated. The results obtained demonstrate for the first time that AMF have the ability to induce systemic resistance against plant parasitic nematodes in a root system.

  18. Disease transmission in an extreme environment: nematode parasites infect reindeer during the Arctic winter.

    PubMed

    Carlsson, Anja M; Justin Irvine, R; Wilson, Kenneth; Piertney, Stuart B; Halvorsen, Odd; Coulson, Stephen J; Stien, Audun; Albon, Steve D

    2012-07-01

    Parasitic nematodes are found in almost all wild vertebrate populations but few studies have investigated these host-parasite relationships in the wild. For parasites with free-living stages, the external environment has a major influence on life-history traits, and development and survival is generally low at sub-zero temperatures. For reindeer that inhabit the high Arctic archipelago of Svalbard, parasite transmission is expected to occur in the summer, due to the extreme environmental conditions and the reduced food intake by the host in winter. Here we show experimentally that, contrary to most parasitic nematodes, Marshallagia marshalli of Svalbard reindeer is transmitted during the Arctic winter. Winter transmission was demonstrated by removing parasites in the autumn, using a novel delayed-release anthelmintic bolus, and estimating re-infection rates in reindeer sampled in October, February and April. Larval stages of nematodes were identified using molecular tools, whereas adult stages were identified using microscopy. The abundance of M. marshalli adult worms and L4s increased significantly from October to April, indicating that reindeer were being infected with L3s from the pasture throughout the winter. To our knowledge, this study is the first to experimentally demonstrate over-winter transmission of a gastro-intestinal nematode parasite in a wild animal. Potential mechanisms associated with this unusual transmission strategy are discussed in light of our knowledge of the life-history traits of this parasite.

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

    PubMed Central

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

    2016-01-01

    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. PMID:26797310

  20. 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)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. Response of Plant Parasitic and Free Living Soil Nematodes to Composted Animal Manure Soil Amendments

    PubMed Central

    Renčo, M.; Kováčik, P.

    2012-01-01

    In an outside pot experiment, dry pig manure processed on pine sawdust litter and fermented for seven days by house fly larvae (fermented manure), and pine sawdust applied alone, and in combination with a spring application of inorganic nitrogen fertilizer were used to determine their effects on plant parasitic and free-living soil nematodes on sugar beets (cv. Antek). Non amended soil was used as a control. All treatments with fermented pig manure and sawdust with nitrogen fertilizer decreased number of plant parasitic nematodes and also root-fungal feeding nematodes compared to the untreated control. Sawdust applied alone had no effect on plant parasitic and root-fungal feeding nematode suppression. Free-living nematodes which were mainly bacteriovores and fungivores were significantly more abundant in soil amended with fermented pig manure, while the sawdust had no effect on these nematodes. The effect of all tested treatments on omnivores-predators was rather random, and in general, the number of these nematodes decreased after soil amendment applications compared to the untreated control. PMID:23482503

  2. Composition of the Cockroach Gut Microbiome in the Presence of Parasitic Nematodes.

    PubMed

    Vicente, Cláudia S L; Ozawa, Sota; Hasegawa, Koichi

    2016-09-29

    Cockroaches are parasitized by thelastomatid nematodes, which live in an obligate manner in their hindgut and interact with the resident microbial community. In the present study, a composition analysis was performed on the gut microbiome of Periplaneta fuliginosa and P. americana to investigate natural and artificial infection by thelastomatid nematodes. Nine libraries of the 16S rRNA gene V3-V4 region were prepared for pyrosequencing. We examined the complete gut microbiome (fore-, mid-, and hindgut) of lab-reared P. fuliginosa naturally infected with the parasitic nematode Leidynema appendiculatum and those that were nematode-free, and complemented our study by characterizing the hindgut microbial communities of lab-reared P. americana naturally infected with Hammerschmidtiella diesingi and Thelastoma bulhoesi, artificially infected with L. appendiculatum, and those that were nematode-free. Our results revealed that the fore- and midgut of naturally infected and nematode-free P. fuliginosa have close microbial communities, which is in contrast with hindgut communities; the hindgut communities of both cockroaches exhibit higher microbial diversities in the presence of their natural parasites and marked differences were observed in the abundance of the most representative taxa, namely Firmicutes, Proteobacteria, and Bacteroidetes. Our results have provided basic information and encourage further studies on multitrophic interactions in the cockroach gut as well as the thelastomatid nematodes that play a role in this environment.

  3. Composition of the Cockroach Gut Microbiome in the Presence of Parasitic Nematodes

    PubMed Central

    Vicente, Cláudia S. L.; Ozawa, Sota; Hasegawa, Koichi

    2016-01-01

    Cockroaches are parasitized by thelastomatid nematodes, which live in an obligate manner in their hindgut and interact with the resident microbial community. In the present study, a composition analysis was performed on the gut microbiome of Periplaneta fuliginosa and P. americana to investigate natural and artificial infection by thelastomatid nematodes. Nine libraries of the 16S rRNA gene V3–V4 region were prepared for pyrosequencing. We examined the complete gut microbiome (fore-, mid-, and hindgut) of lab-reared P. fuliginosa naturally infected with the parasitic nematode Leidynema appendiculatum and those that were nematode-free, and complemented our study by characterizing the hindgut microbial communities of lab-reared P. americana naturally infected with Hammerschmidtiella diesingi and Thelastoma bulhoesi, artificially infected with L. appendiculatum, and those that were nematode-free. Our results revealed that the fore- and midgut of naturally infected and nematode-free P. fuliginosa have close microbial communities, which is in contrast with hindgut communities; the hindgut communities of both cockroaches exhibit higher microbial diversities in the presence of their natural parasites and marked differences were observed in the abundance of the most representative taxa, namely Firmicutes, Proteobacteria, and Bacteroidetes. Our results have provided basic information and encourage further studies on multitrophic interactions in the cockroach gut as well as the thelastomatid nematodes that play a role in this environment. PMID:27524304

  4. Response of plant parasitic and free living soil nematodes to composted animal manure soil amendments.

    PubMed

    Renčo, M; Kováčik, P

    2012-12-01

    In an outside pot experiment, dry pig manure processed on pine sawdust litter and fermented for seven days by house fly larvae (fermented manure), and pine sawdust applied alone, and in combination with a spring application of inorganic nitrogen fertilizer were used to determine their effects on plant parasitic and free-living soil nematodes on sugar beets (cv. Antek). Non amended soil was used as a control. All treatments with fermented pig manure and sawdust with nitrogen fertilizer decreased number of plant parasitic nematodes and also root-fungal feeding nematodes compared to the untreated control. Sawdust applied alone had no effect on plant parasitic and root-fungal feeding nematode suppression. Free-living nematodes which were mainly bacteriovores and fungivores were significantly more abundant in soil amended with fermented pig manure, while the sawdust had no effect on these nematodes. The effect of all tested treatments on omnivores-predators was rather random, and in general, the number of these nematodes decreased after soil amendment applications compared to the untreated control.

  5. Nematode Hsp90: highly conserved but functionally diverse.

    PubMed

    Gillan, Victoria; Devaney, Eileen

    2014-08-01

    Nematodes are amongst the most successful and abundant organisms on the planet with approximately 30 000 species described, although the actual number of species is estimated to be one million or more. Despite sharing a relatively simple and invariant body plan, there is considerable diversity within the phylum. Nematodes have evolved to colonize most ecological niches, and can be free-living or can parasitize plants or animals to the detriment of the host organism. In this review we consider the role of heat shock protein 90 (Hsp90) in the nematode life cycle. We describe studies on Hsp90 in the free-living nematode Caenorhabditis elegans and comparative work on the parasitic species Brugia pahangi, and consider whether a dependence upon Hsp90 can be exploited for the control of parasitic species. PMID:24721950

  6. Sequence and genetic map of Meloidogyne hapla: A compact nematode genome for plant parasitism

    PubMed Central

    Opperman, Charles H.; Bird, David M.; Williamson, Valerie M.; Rokhsar, Dan S.; Burke, Mark; Cohn, Jonathan; Cromer, John; Diener, Steve; Gajan, Jim; Graham, Steve; Houfek, T. D.; Liu, Qingli; Mitros, Therese; Schaff, Jennifer; Schaffer, Reenah; Scholl, Elizabeth; Sosinski, Bryon R.; Thomas, Varghese P.; Windham, Eric

    2008-01-01

    We have established Meloidogyne hapla as a tractable model plant-parasitic nematode amenable to forward and reverse genetics, and we present a complete genome sequence. At 54 Mbp, M. hapla represents not only the smallest nematode genome yet completed, but also the smallest metazoan, and defines a platform to elucidate mechanisms of parasitism by what is the largest uncontrolled group of plant pathogens worldwide. The M. hapla genome encodes significantly fewer genes than does the free-living nematode Caenorhabditis elegans (most notably through a reduction of odorant receptors and other gene families), yet it has acquired horizontally from other kingdoms numerous genes suspected to be involved in adaptations to parasitism. In some cases, amplification and tandem duplication have occurred with genes suspected of being acquired horizontally and involved in parasitism of plants. Although M. hapla and C. elegans diverged >500 million years ago, many developmental and biochemical pathways, including those for dauer formation and RNAi, are conserved. Although overall genome organization is not conserved, there are areas of microsynteny that may suggest a primary biological function in nematodes for those genes in these areas. This sequence and map represent a wealth of biological information on both the nature of nematode parasitism of plants and its evolution. PMID:18809916

  7. Intravascular filarial parasites elaborate cyclooxygenase-derived eicosanoids

    PubMed Central

    1990-01-01

    The nematode parasites that cause human lymphatic filariasis survive for long periods in their vascular habitats despite continual exposure to host cells. Since prostanoids formed from arachidonic acid can modulate interactions among platelets, leukocytes, and endothelial cells, we examined whether intravascular nematode parasites can elaborate prostanoids. Microfilariae of Brugia malayi utilize exogenous and endogenous arachidonic acid to generate and release two predominant prostanoids, prostacyclin and prostaglandin E2. Filarial metabolism of host fatty acids to form these vasodilatory, antiaggregatory, and immunomodulatory eicosanoids provides a means by which these helminthic parasites may influence host immune and other cellular responses. PMID:2117642

  8. The dual effects of root-cap exudates on nematodes: from quiescence in plant-parasitic nematodes to frenzy in entomopathogenic nematodes.

    PubMed

    Hiltpold, Ivan; Jaffuel, Geoffrey; Turlings, Ted C J

    2015-02-01

    To defend themselves against herbivores and pathogens, plants produce numerous secondary metabolites, either constitutively or de novo in response to attacks. An intriguing constitutive example is the exudate produced by certain root-cap cells that can induce a state of reversible quiescence in plant-parasitic nematodes, thereby providing protection against these antagonists. The effect of such root exudates on beneficial entomopathogenic nematodes (EPNs) remains unclear, but could potentially impair their use in pest management programmes. We therefore tested how the exudates secreted by green pea (Pisum sativum) root caps affect four commercial EPN species. The exudates induced reversible quiescence in all EPN species tested. Quiescence levels varied with the green pea cultivars tested. Notably, after storage in root exudate, EPN performance traits were maintained over time, whereas performances of EPNs stored in water rapidly declined. In sharp contrast to high concentrations, lower concentrations of the exudate resulted in a significant increase in EPN activity and infectiousness, but still reduced the activity of two plant-parasitic nematode species. Our study suggests a finely tuned dual bioactivity of the exudate from green pea root caps. Appropriately formulated, it can favour long-term storage of EPNs and boost their infectiousness, while it may also be used to protect plants from plant-parasitic nematodes.

  9. The novel GrCEP12 peptide from the plant-parasitic nematode Globodera rostochiensis suppresses flg22-mediated PTI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potato cyst nematode Globodera rostochiensis is a biotrophic pathogen that secretes effector proteins into host root cells to promote successful plant parasitism. In addition to the role in generating within root tissue the feeding cells essential for nematode development, nematode secreted effe...

  10. Serological Differentiation of Plant-parasitic Nematode Species with Polyclonal and Monoclonal Antibodies

    PubMed Central

    Schots, Arjen; Gommers, Fred J.; Bakker, Jaap; Egberts, Egbert

    1990-01-01

    Although several attempts have been made to differentiate nematode species with polyclonal antisera, these efforts thus far have met with limited success because of extensive crossreactivities of the sera. Since the hybridoma technique offers the opportunity to develop more specific serological reagents, some research groups have recently started to apply this technology to the problem of species identification in nematology. Monoclonal antibodies (MA) that differentiate the potato-cyst nematodes Globodera rostochiensis and G. pallida, as well as MA specific for Meloidogyne species, have been developed. The possibilities of developing serodiagnostic tools for identification of nematodes recovered from soil samples and the implications of such monitoring of nematode infestations in view of integrated control of plant-parasitic nematodes are discussed. PMID:19287684

  11. Biocontrol: Bacillus penetrans and Related Parasites of Nematodes

    PubMed Central

    Sayre, R. M.

    1980-01-01

    Bacillus penetrans Mankau, 1975, previously described as Duboscqia penetrans Thorne 1940, is a candidate agent for biocontrol of nematodes. This review considers the life stages of this bacterium: vegetative growth phase, colony fragmentation, sporogenesis, soil phase, spore attachment, and penetration into larvae of root-knot nematodes. The morphology of the microthallus colonies and the unusual external features of the spore are discussed. Taxonomic affinities with the actinomycetes, particularly with the genus Pasteuria, are considered. Also discussed are other soil bacterial species that are potential biocontrol agents. Products of their bacterial fermentation in soil are toxic to nematodes, making them effective biocontrol agents. PMID:19300701

  12. Biological control of gastrointestinal parasitic nematodes using Duddingtonia flagrans in sheep under natural conditions in Mexico.

    PubMed

    Mendoza-De Gives, Pedro; Zapata Nieto, Claudia; Hernández, Enrique Liébano; Arellano, María Eugenia López; Rodríguez, David Herrera; Garduño, Roberto González

    2006-10-01

    This investigation was aimed to evaluate the use of an oral bio-preparation containing Duddingtonia flagrans chlamydospores for the control of sheep gastrointestinal parasitic nematodes under the Mexican cold high plateau conditions. Two groups of gastrointestinal parasitic nematode naturally infected sheep, were randomly selected and located into two free-gastrointestinal nematode larvae paddocks. Group 1 received once a week a supplement containing D. flagrans chlamydospores mixed with oats and molasses. Group 2 received a similar supplement without any fungal material. After 5 months grazing animals were discarded from the experiment and two groups of free-nematode "tracer" sheep were located into the same paddocks to collect larvae from the contaminated pastures. Animals were slaughtered and necropsied and the nematodes were obtained and counted. A screening of the number of gastrointestinal nematode larvae present on the grass was performed and compared between the two grazing areas. The results showed 56% reduction in the Ostertagia (Teladorsagia) circumcincta and 94% reduction in the Nematodirus sp. population of the "tracer" sheep who grazed on the D. flagrans-treated sheep area, compared to the nematode population in animals grazed on the non-treated area. The results of the number of larvae on the grazing pastures showed a 51.1% reduction for H. contortus, and 100% for Cooperia sp. in the area with fungi. In the case of Trichostrongylus sp. no reduction was observed, when compared to the control group.

  13. Biological control of gastrointestinal parasitic nematodes using Duddingtonia flagrans in sheep under natural conditions in Mexico.

    PubMed

    Mendoza-De Gives, Pedro; Zapata Nieto, Claudia; Hernández, Enrique Liébano; Arellano, María Eugenia López; Rodríguez, David Herrera; Garduño, Roberto González

    2006-10-01

    This investigation was aimed to evaluate the use of an oral bio-preparation containing Duddingtonia flagrans chlamydospores for the control of sheep gastrointestinal parasitic nematodes under the Mexican cold high plateau conditions. Two groups of gastrointestinal parasitic nematode naturally infected sheep, were randomly selected and located into two free-gastrointestinal nematode larvae paddocks. Group 1 received once a week a supplement containing D. flagrans chlamydospores mixed with oats and molasses. Group 2 received a similar supplement without any fungal material. After 5 months grazing animals were discarded from the experiment and two groups of free-nematode "tracer" sheep were located into the same paddocks to collect larvae from the contaminated pastures. Animals were slaughtered and necropsied and the nematodes were obtained and counted. A screening of the number of gastrointestinal nematode larvae present on the grass was performed and compared between the two grazing areas. The results showed 56% reduction in the Ostertagia (Teladorsagia) circumcincta and 94% reduction in the Nematodirus sp. population of the "tracer" sheep who grazed on the D. flagrans-treated sheep area, compared to the nematode population in animals grazed on the non-treated area. The results of the number of larvae on the grazing pastures showed a 51.1% reduction for H. contortus, and 100% for Cooperia sp. in the area with fungi. In the case of Trichostrongylus sp. no reduction was observed, when compared to the control group. PMID:17135538

  14. Fighting while parasitized: can nematode infections affect the outcome of staged combat in beetles?

    PubMed

    Vasquez, David; Willoughby, Anna; Davis, Andrew K

    2015-01-01

    The effects of non-lethal parasites may be felt most strongly when hosts engage in intense, energy-demanding behaviors. One such behavior is fighting with conspecifics, which is common among territorial animals, including many beetle species. We examined the effects of parasites on the fighting ability of a saproxylic beetle, the horned passalus (Odontotaenius disjunctus, Family: Passalidae), which is host to a non-lethal nematode, Chondronema passali. We pitted pairs of randomly-chosen (but equally-weighted) beetles against each other in a small arena and determined the winner and aggression level of fights. Then we examined beetles for the presence, and severity of nematode infections. There was a non-significant tendency (p = 0.065) for the frequency of wins, losses and draws to differ between beetles with and without C. passali; non-parasitized individuals (n = 104) won 47% of their fights while those with the parasite (n = 88) won 34%, a 13% difference in wins. The number of nematodes in a beetle affected the outcome of fights between infected and uninfected individuals in an unexpected fashion: fighting ability was lowest in beetles with the lowest (p = 0.033), not highest (p = 0.266), nematode burdens. Within-fight aggression was highest when both beetles were uninfected and lowest when both were infected (p = 0.034). Collectively, these results suggest the nematode parasite, C. passali, is associated with a modest reduction in fighting ability in horned passalus beetles, consistent with the idea that parasitized beetles have lower energy available for fighting. This study adds to a small but growing body of evidence showing how parasites negatively influence fighting behavior in animals.

  15. Fighting while Parasitized: Can Nematode Infections Affect the Outcome of Staged Combat in Beetles?

    PubMed Central

    Vasquez, David; Willoughby, Anna; Davis, Andrew K.

    2015-01-01

    The effects of non-lethal parasites may be felt most strongly when hosts engage in intense, energy-demanding behaviors. One such behavior is fighting with conspecifics, which is common among territorial animals, including many beetle species. We examined the effects of parasites on the fighting ability of a saproxylic beetle, the horned passalus (Odontotaenius disjunctus, Family: Passalidae), which is host to a non-lethal nematode, Chondronema passali. We pitted pairs of randomly-chosen (but equally-weighted) beetles against each other in a small arena and determined the winner and aggression level of fights. Then we examined beetles for the presence, and severity of nematode infections. There was a non-significant tendency (p = 0.065) for the frequency of wins, losses and draws to differ between beetles with and without C. passali; non-parasitized individuals (n = 104) won 47% of their fights while those with the parasite (n = 88) won 34%, a 13% difference in wins. The number of nematodes in a beetle affected the outcome of fights between infected and uninfected individuals in an unexpected fashion: fighting ability was lowest in beetles with the lowest (p = 0.033), not highest (p = 0.266), nematode burdens. Within-fight aggression was highest when both beetles were uninfected and lowest when both were infected (p = 0.034). Collectively, these results suggest the nematode parasite, C. passali, is associated with a modest reduction in fighting ability in horned passalus beetles, consistent with the idea that parasitized beetles have lower energy available for fighting. This study adds to a small but growing body of evidence showing how parasites negatively influence fighting behavior in animals. PMID:25830367

  16. The role of nematophagous fungi in the biological control of nematode parasites of livestock.

    PubMed

    Waller, P J; Larsen, M

    1993-07-01

    The control of nematode parasites of livestock is presently based entirely on anthelmintic treatment and grazing management. On their own, these methods are not sustainable because parasites invariably develop resistance to anthelmintics and because of increasing public concern about chemical residues in livestock products and the environment. Although alternative, non-chemotherapeutic control strategies, such as vaccines and genetic selection for resistance are the focus of considerable research activity worldwide, biological control of nematode parasites has been virtually ignored. The little work that has been done is restricted largely to western Europe and involves virtually just one fungal species, namely Arthrobotrys oligospora. More recent studies indicate other known nematophagous fungal species are more efficient predators of infective larvae in sheep faeces than A. oligospora, and others have a greater capacity to survive passage through the gastrointestinal tract of ruminants. These findings plus the relatively sparse numbers of microbial competitors in the fresh faecal environment, compared with the plant rhizosphere where biological control of plant parasites is proving a particularly intractable problem, engenders optimism that the biological control of animal parasitic nematodes may become a practical reality. Such control will never be a substitute for chemotherapy, where the primary purpose is worm removal from the host, but should be incorporated together with other options into integrated pest management systems to provide sustainable nematode control of livestock into the twenty-first century.

  17. Parasitism of Molluscs by Nematodes: Types of Associations and Evolutionary Trends

    PubMed Central

    Grewal, P. S.; Grewal, S. K.; Tan, L.; Adams, B. J.

    2003-01-01

    Although there are no confirmed fossil records of mollusc parasitic nematodes, diverse associations of more than 108 described nematode species with slugs and snails provide a fertile ground for speculation of how mollusc parasitism evolved in nematodes. Current phylogenic resolution suggests that molluscs have been independently acquired as hosts on a number of occasions. However, molluscs are significant as hosts for only two major groups of nematodes: as intermediate hosts for metastrongyloids and as definitive hosts for a number of rhabditids. Of the 61 species of nematodes known to use molluscs as intermediate hosts, 49 belong to Metastrongyloidea (Order Strongylida); of the 47 species of nematodes that use molluscs as definitive hosts, 33 belong to the Order Rhabditida. Recent phylogenetic hypotheses have been unable to resolve whether metastrongyloids are sister taxa to those rhabditids that use molluscs as definitive hosts. Although most rhabditid nematodes have been reported not to kill their mollusc hosts prior to their reproduction, some species are pathogenic. In fact, infective juveniles of Phasmarhabditis hermaphrodita vector a lethal bacterium into the slug host in which they reproduce. This life cycle is remarkably similar to the entomopathogenic nematodes in the families Steinernematidae and Heterorhabditidae. Also, the discoveries of Alloionema and Pellioditis in slugs are interesting, as these species have been speculated to represent the ancestral forms of the entomopathogenic nematodes. Development of the infective stage appears to be an important step toward the acquisition of molluscs as definitive hosts, and the association with specific bacteria may have arisen in conjunction with the evolution of necromeny. PMID:19265989

  18. Serine Protease-mediated Host Invasion by the Parasitic Nematode Steinernema carpocapsae*

    PubMed Central

    Toubarro, Duarte; Lucena-Robles, Miguel; Nascimento, Gisela; Santos, Romana; Montiel, Rafael; Veríssimo, Paula; Pires, Euclides; Faro, Carlos; Coelho, Ana V.; Simões, Nelson

    2010-01-01

    Steinernema carpocapsae is an insect parasitic nematode used in biological control, which infects insects penetrating by mouth and anus and invading the hemocoelium through the midgut wall. Invasion has been described as a key factor in nematode virulence and suggested to be mediated by proteases. A serine protease cDNA from the parasitic stage was sequenced (sc-sp-1); the recombinant protein was produced in an Escherichia coli system, and a native protein was purified from the secreted products. Both proteins were confirmed by mass spectrometry to be encoded by the sc-sp-1 gene. Sc-SP-1 has a pI of 8.7, a molecular mass of 27.3 kDa, a catalytic efficiency of 22.2 × 104 s−1 m−1 against N-succinyl-Ala-Ala-Pro-Phe-pNA, and is inhibited by chymostatin (IC 0.07) and PMSF (IC 0.73). Sc-SP-1 belongs to the chymotrypsin family, based on sequence and biochemical analysis. Only the nematode parasitic stage expressed sc-sp-1. These nematodes in the midgut lumen, prepared to invade the insect hemocoelium, expressed higher levels than those already in the hemocoelium. Moreover, parasitic nematode sense insect peritrophic membrane and hemolymph more quickly than they do other tissues, which initiates sc-sp-1 expression. Ex vivo, Sc-SP-1 was able to bind to insect midgut epithelium and to cause cell detachment from basal lamina. In vitro, Sc-SP-1 formed holes in an artificial membrane model (Matrigel), whereas Sc-SP-1 treated with PMSF did not, very likely because it hydrolyzes matrix glycoproteins. These findings highlight the S. carpocapsae-invasive process that is a key step in the parasitism thus opening new perspectives for improving nematode virulence to use in biological control. PMID:20656686

  19. Detection and quantification of root-knot nematode (Meloidogyne javanica), lesion nematode (Pratylenchus zeae) and dagger nematode (Xiphinema elongatum) parasites of sugarcane using real-time PCR.

    PubMed

    Berry, Shaun D; Fargette, Mireille; Spaull, Vaughan W; Morand, Serge; Cadet, Patrice

    2008-06-01

    A number of different plant parasitic nematode species are found associated with sugarcane in South Africa. Of these, the root-knot nematode (Meloidogyne javanica), the lesion nematode (Pratylenchus zeae) and the dagger nematode (Xiphinema elongatum) are potentially the most damaging pests. Identification and enumeration of the number of these nematodes are necessary for providing advice to farmers as well as studying the effects of various treatments in field and glasshouse trials. We report on the development, use, and extent of specificity of three sets of primers, for M. javanica, P. zeae and X. elongatum, and on tests to detect and quantify the number of these nematodes in soil samples using SYBR Green I dye and real-time PCR technology. Amplicons from the three target species (obtained with their respective primer sets) are discernible in size by gel electrophoresis (380bp for M. javanica, 250bp for P. zeae and 500bp for X. elongatum). Also, these amplicons have characteristic melting temperatures of 83.8 degrees C (M. javanica), 86.6 degrees C (P. zeae) and 86.1 degrees C (X. elongatum). Investigations into multiplex reactions found competition between species with M. javanica competing with P. zeae and X. elongatum. Subsequent single tube (simplex) assays, enabled the construction of calibration curves for each of the three species. These were then used for quantification of the numbers of each of these species in nematode samples extracted from the field, with a high (R2=0.83) and significant positive correlation between real-time PCR and counts performed with microscopy.

  20. On the track of transfer cell formation by specialized plant-parasitic nematodes

    PubMed Central

    Rodiuc, Natalia; Vieira, Paulo; Banora, Mohamed Youssef; de Almeida Engler, Janice

    2014-01-01

    Transfer cells are ubiquitous plant cells that play an important role in plant development as well as in responses to biotic and abiotic stresses. They are highly specialized and differentiated cells playing a central role in the acquisition, distribution and exchange of nutrients. Their unique structural traits are characterized by augmented ingrowths of invaginated secondary wall material, unsheathed by an amplified area of plasma membrane enriched in a suite of solute transporters. Similar morphological features can be perceived in vascular root feeding cells induced by sedentary plant-parasitic nematodes, such as root-knot and cyst nematodes, in a wide range of plant hosts. Despite their close phylogenetic relationship, these obligatory biotrophic plant pathogens engage different approaches when reprogramming root cells into giant cells or syncytia, respectively. Both nematode feeding-cells types will serve as the main source of nutrients until the end of the nematode life cycle. In both cases, these nematodes are able to remarkably maneuver and reprogram plant host cells. In this review we will discuss the structure, function and formation of these specialized multinucleate cells that act as nutrient transfer cells accumulating and synthesizing components needed for survival and successful offspring of plant-parasitic nematodes. Plant cells with transfer-like functions are also a renowned subject of interest involving still poorly understood molecular and cellular transport processes. PMID:24847336

  1. Serine/threonine phosphatases in socioeconomically important parasitic nematodes--prospects as novel drug targets?

    PubMed

    Campbell, Bronwyn E; Hofmann, Andreas; McCluskey, Adam; Gasser, Robin B

    2011-01-01

    Little is known about the fundamental biology of parasitic nematodes (=roundworms) that cause serious diseases, affecting literally billions of animals and humans worldwide. Unlocking the biology of these neglected pathogens using modern technologies will yield crucial and profound knowledge of their molecular biology, and could lead to new treatment and control strategies. Supported by studies in the free-living nematode, Caenorhabditis elegans, some recent investigations have provided improved insights into selected protein phosphatases (PPs) of economically important parasitic nematodes (Strongylida). In the present article, we review this progress and assess the potential of serine/threonine phosphatase (STP) genes and/or their products as targets for new nematocidal drugs. Current information indicates that some small molecules, known to specifically inhibit PPs, might be developed as nematocides. For instance, some cantharidin analogues are known to display exquisite PP-inhibitor activity, which indicates that some of them could be designed and tailored to specifically inhibit selected STPs of nematodes. This information provides prospects for the discovery of an entirely novel class of nematocides, which is of paramount importance, given the serious problems linked to anthelmintic resistance in parasitic nematode populations of livestock, and has the potential to lead to significant biotechnological outcomes. PMID:20732402

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

    PubMed Central

    Duguet, Thomas B.; Charvet, Claude L.; Forrester, Sean G.; Wever, Claudia M.; Dent, Joseph A.; Neveu, Cedric; Beech, Robin N.

    2016-01-01

    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 clade V parasitic

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

    PubMed

    Duguet, Thomas B; Charvet, Claude L; Forrester, Sean G; Wever, Claudia M; Dent, Joseph A; Neveu, Cedric; Beech, Robin N

    2016-07-01

    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 clade V parasitic

  4. The prospects for biological control of the free-living stages of nematode parasites of livestock.

    PubMed

    Waller, P J; Faedo, M

    1996-01-01

    Control of nematode parasites of livestock is focused almost entirely on the parasitic stages within the host. Current methods rely on anthelmintic drugs, but these are under increasing threat with the development of resistance covering the whole spectrum of anthelmintics amongst the important nematode species of a range of livestock. However, invariably the greatest proportion of the parasite biomass resides not within the animal hosts, but in the external environment-commonly on pasture. It is in this environment that the free-living stages are vulnerable to a range of abiotic factors (extremes in temperature and desiccation) and biotic factors (macro- and micro-organisms) that may decimate their numbers. Of the latter, there are organisms, which exert their effects either indirectly by rendering faecal deposits inimical for the development of nematode eggs through to infective larvae, or directly by acting as pathogens or by exploiting the free-living stages as a food source. Within this vast assemblage of organisms, which include microarthropods, protozoa, viruses, bacteria and fungi, could well emerge a variety of biological control agents of nematode parasites. At present, greatest interest lies with the nematode-destroying fungi. Work has progressed from Petri dishes, to plots, to paddocks with several species of the genus Arthrobotrys and Duddingtonia flagrans. These studies indicate that the voracious nematophagous capabilities of these fungi, clearly demonstrated in vitro, translate to reductions in the number of infective larvae on pasture and indicate that levels of control, comparable to conventional schemes using anthelmintics, can be achieved. The challenge now lies in developing methods of administration of fungi to animals which can be applied under practical farm conditions. However, the pursuit of candidates for biological control of nematode parasites of livestock should not involve just a few species of nematophagous fungi. More than 100

  5. Community Composition of Plant-parasitic Nematodes in Native and Cultivated Cerrados of Central Brazil

    PubMed Central

    Huang, S. P.; Cares, J. H.

    1995-01-01

    Communities of plant-parasitic nematodes collected from five different vegetation types (canopy woodland, savannah, gallery forest, cultivated perennial, and annual plants) and soils (yellowish red latosols, dark red latosols, arenosols, acrisols, and gleysols) were studied. Ninety percent of the soil samples collected from savannah contained at least four genera of plant-parasitic nematodes. The highest population densities were recovered from perennial plants and from acrisols. Nematodes from perennial and annual plants formed one cluster, which had a similar flexible-beta distance to that from the gallery forest. The distance in the native savannah and in canopy woodland was very different. Distance values for the soil aspect were similar for arenosols, yellowish, and dark red latosols. The value for acrisols was much larger than for the other soils. PMID:19277285

  6. Ascarosides coordinate the dispersal of a plant-parasitic nematode with the metamorphosis of its vector beetle.

    PubMed

    Zhao, Lilin; Zhang, Xinxing; Wei, Yanan; Zhou, Jiao; Zhang, Wei; Qin, Peijun; Chinta, Satya; Kong, Xiangbo; Liu, Yunpeng; Yu, Haiying; Hu, Songnian; Zou, Zhen; Butcher, Rebecca A; Sun, Jianghua

    2016-01-01

    Insect vectors are required for the transmission of many species of parasitic nematodes, but the mechanisms by which the vectors and nematodes coordinate their life cycles are poorly understood. Here, we report that ascarosides, an evolutionarily conserved family of nematode pheromones, are produced not only by a plant-parasitic nematode, but also by its vector beetle. The pinewood nematode and its vector beetle cause pine wilt disease, which threatens forest ecosystems world-wide. Ascarosides secreted by the dispersal third-stage nematode LIII larvae promote beetle pupation by inducing ecdysone production in the beetle and up-regulating ecdysone-dependent gene expression. Once the beetle develops into the adult stage, it secretes ascarosides that attract the dispersal fourth-stage nematode LIV larvae, potentially facilitating their movement into the beetle trachea for transport to the next pine tree. These results demonstrate that ascarosides play a key role in the survival and spread of pine wilt disease. PMID:27477780

  7. Ascarosides coordinate the dispersal of a plant-parasitic nematode with the metamorphosis of its vector beetle

    PubMed Central

    Zhao, Lilin; Zhang, Xinxing; Wei, Yanan; Zhou, Jiao; Zhang, Wei; Qin, Peijun; Chinta, Satya; Kong, Xiangbo; Liu, Yunpeng; Yu, Haiying; Hu, Songnian; Zou, Zhen; Butcher, Rebecca A.; Sun, Jianghua

    2016-01-01

    Insect vectors are required for the transmission of many species of parasitic nematodes, but the mechanisms by which the vectors and nematodes coordinate their life cycles are poorly understood. Here, we report that ascarosides, an evolutionarily conserved family of nematode pheromones, are produced not only by a plant-parasitic nematode, but also by its vector beetle. The pinewood nematode and its vector beetle cause pine wilt disease, which threatens forest ecosystems world-wide. Ascarosides secreted by the dispersal third-stage nematode LIII larvae promote beetle pupation by inducing ecdysone production in the beetle and up-regulating ecdysone-dependent gene expression. Once the beetle develops into the adult stage, it secretes ascarosides that attract the dispersal fourth-stage nematode LIV larvae, potentially facilitating their movement into the beetle trachea for transport to the next pine tree. These results demonstrate that ascarosides play a key role in the survival and spread of pine wilt disease. PMID:27477780

  8. Potential of Foliar, Dip, and Injection Applications of Avermectins for Control of Plant-Parasitic Nematodes

    PubMed Central

    Jansson, Richard K.; Rabatin, Susan

    1998-01-01

    Studies were conducted to determine the potential of two avermectin compounds, abamectin and emamectin benzoate, for controlling plant-parasitic nematodes when applied by three methods: foliar spray, root dip, and pseudostem injection. Experiments were conducted against Meloidogyne incognita on tomato, M. javanica on banana, and Radopholus similis on banana. Foliar applications of both avermectins to banana and tomato were not effective for controlling any of the nematodes evaluated. Root dips of banana and tomato were moderately effective for controlling M. incognita on tomato and R. similis on banana. Injections (1 ml) of avermectins into banana pseudostems were effective for controlling M. javanica and R similis, and were comparable to control achieved with a conventional chemical nematicide, fenamiphos. Injections of 125 to 2,000 μg/plant effectively controlled one or both nematodes on banana; abamectin was more effective than emamectin benzoate for controlling nematodes. PMID:19274200

  9. Invasion, establishment, and range expansion of two parasitic nematodes in the Canadian Arctic

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate warming is modifying host-parasite interactions in the Arctic. Invasion of an arctic island by protostrongylid nematodes appears mediated by sporadic dispersal of muskoxen and seasonal migration by caribou from the Canadian mainland. A newly permissive environment likely facilitated initial ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. De novo transcriptome assembly of the plant-parasitic nematode Rotylenchulus reniformis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rotylenchulus reniformis, commonly known as the reniform nematode, is a pathogen of cotton, soybean, and sweet potatoes in the Southeastern United States. An estimate of cotton production loss due to R. reniformis parasitism in the United States in 2011 was 279,000 bales. Here, we present a de novo...

  12. Anaerobic Soil Disinfestation (ASD) and Steam As Alternatives For Parasitic Nematode Control In Florida Floriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic soil disinfestation (ASD) and steam are being investigated for controlling a broad spectrum of pests, including parasitic nematodes and weeds. ASD is a biologically-based method that combines organic amendments and solar heat with water saturated soil to create oxygen-depleted soil co...

  13. Differential behavioral responses of two plant-parasitic nematodes to biogenic amines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hatching and infective juvenile (J2) behavior in two species of plant-parasitic nematodes, Heterodera glycines and Meloidogyne incognita, were affected by in vitro treatment with the biogenic amines dopamine, octopamine, and serotonin. While the overall responses of each species to amine exposures w...

  14. B cells have distinct roles in host protection against different nematode parasites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    B cells may mediate protective responses against nematode parasites by supporting Th2 cell development and/or by producing antibodies. To examine this, B cell-deficient mice were inoculated with Nippostrongylus brasiliensis (Nb) or Heligmosomoides polygyrus (Hp). B cell-deficient and wild type (WT...

  15. Spatial Distribution of Plant-Parasitic Nematodes in Semi-Arid Vitis vinifera Vineyards in Washington

    PubMed Central

    Howland, Amanda D.; Schreiner, R. Paul; Zasada, Inga A.

    2014-01-01

    The most commonly encountered plant-parasitic nematodes in eastern Washington Vitis vinifera vineyards are Meloidogyne hapla, Mesocriconema xenoplax, Pratylenchus spp., Xiphinema americanum, and Paratylenchus sp.; however, little is known about their distribution in the soil profile. The vertical and horizontal spatial distribution of plant-parasitic nematodes was determined in two Washington V. vinifera vineyards. Others variables measured in these vineyards included soil moisture content, fine root biomass, and root colonization by arbuscular mycorhizal fungi (AMF). Meloidogyne hapla and M. xenoplax were aggregated under irrigation emitters within the vine row and decreased with soil depth. Conversely, Pratylenchus spp. populations were primarily concentrated in vineyard alleyways and decreased with depth. Paratylenchus sp. and X. americanum were randomly distributed within the vineyards. Soil water content played a dominant role in the distribution of fine roots and plant-parasitic nematodes. Colonization of fine roots by AMF decreased directly under irrigation emitters; in addition, galled roots had lower levels of AMF colonization compared with healthy roots. These findings will help facilitate sampling and management decisions for plant-parasitic nematodes in Washington semi-arid vineyards. PMID:25580024

  16. Evaluation of anthelmintic resistance of intestinal parasitic nematodes in heifers in south central Nebraska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Internal parasitic nematodes impact the livestock industry through losses in reproductive efficiency, rate of gain, carcass quality, milk production, or immune response. The frequent use of anthelmintics with drug formulations in which chemical activity persists for long periods selects for worm re...

  17. Spatial Distribution of Plant-Parasitic Nematodes in Semi-Arid Vitis vinifera Vineyards in Washington.

    PubMed

    Howland, Amanda D; Schreiner, R Paul; Zasada, Inga A

    2014-12-01

    The most commonly encountered plant-parasitic nematodes in eastern Washington Vitis vinifera vineyards are Meloidogyne hapla, Mesocriconema xenoplax, Pratylenchus spp., Xiphinema americanum, and Paratylenchus sp.; however, little is known about their distribution in the soil profile. The vertical and horizontal spatial distribution of plant-parasitic nematodes was determined in two Washington V. vinifera vineyards. Others variables measured in these vineyards included soil moisture content, fine root biomass, and root colonization by arbuscular mycorhizal fungi (AMF). Meloidogyne hapla and M. xenoplax were aggregated under irrigation emitters within the vine row and decreased with soil depth. Conversely, Pratylenchus spp. populations were primarily concentrated in vineyard alleyways and decreased with depth. Paratylenchus sp. and X. americanum were randomly distributed within the vineyards. Soil water content played a dominant role in the distribution of fine roots and plant-parasitic nematodes. Colonization of fine roots by AMF decreased directly under irrigation emitters; in addition, galled roots had lower levels of AMF colonization compared with healthy roots. These findings will help facilitate sampling and management decisions for plant-parasitic nematodes in Washington semi-arid vineyards. PMID:25580024

  18. Spatial Distribution of Plant-Parasitic Nematodes in Semi-Arid Vitis vinifera Vineyards in Washington.

    PubMed

    Howland, Amanda D; Schreiner, R Paul; Zasada, Inga A

    2014-12-01

    The most commonly encountered plant-parasitic nematodes in eastern Washington Vitis vinifera vineyards are Meloidogyne hapla, Mesocriconema xenoplax, Pratylenchus spp., Xiphinema americanum, and Paratylenchus sp.; however, little is known about their distribution in the soil profile. The vertical and horizontal spatial distribution of plant-parasitic nematodes was determined in two Washington V. vinifera vineyards. Others variables measured in these vineyards included soil moisture content, fine root biomass, and root colonization by arbuscular mycorhizal fungi (AMF). Meloidogyne hapla and M. xenoplax were aggregated under irrigation emitters within the vine row and decreased with soil depth. Conversely, Pratylenchus spp. populations were primarily concentrated in vineyard alleyways and decreased with depth. Paratylenchus sp. and X. americanum were randomly distributed within the vineyards. Soil water content played a dominant role in the distribution of fine roots and plant-parasitic nematodes. Colonization of fine roots by AMF decreased directly under irrigation emitters; in addition, galled roots had lower levels of AMF colonization compared with healthy roots. These findings will help facilitate sampling and management decisions for plant-parasitic nematodes in Washington semi-arid vineyards.

  19. Evaluation of an antibiotic producing strain of Pseudomonas flourescens for suppression of plant-parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The antibiotic 2,4-diacetylphloroglucinol (DAPG), produced by some strains of Pseudomonas spp., is involved in suppression of several fungal root pathogens as well as plant-parasitic nematodes. The primary objective of this study was to determine whether Wood1R, a D-genotype strain of DAPG-producin...

  20. Factors Affecting Population Trends of Plant-Parasitic Nematodes on Rangeland Grasses

    PubMed Central

    Griffin, G. D.; Asay, K. H.; Horton, W. H.

    1996-01-01

    The effects of environmental conditions on population trends of plant-parasitic nematodes were studied in experimental plots of five wheatgrasses in the western Utah desert. In a 3-year (1984-86) field study, soil water and temperature affected the population trends of the ectoparasites, Tylenchorhynchus acutoides and Xiphinema americanum, and the migratory endoparasite, Pratylenchus neglectus, on Fairway crested wheatgrass, Agropyron cristatum; 'Hycrest' crested wheatgrass, A. cristatum X A. desertorura; 'Rosana' western wheatgrass, Pascopyrum smithii; 'Oahe' intermediate wheatgrass, Thinopyrum intermedium; and RS-1 hybrid (Elytrigia repens X Pseudoroegneria spicata). The largest soil populations of these nematode species were collected in 1984 under good plant-growth conditions. A reduction in nematode populations occurred in 1985 and 1986, possibly because of low soil-water conditions. There was a positive relationship between high soil water and maximum population densities of T. acutoides in the spring and fall of 1984, and between low soil water and minimum population densities of the nematode in 1985 and 1986. Pratylenchus neglectus populations were affected by soil water, although to a lesser degree than the ectoparasitic nematodes. Population densities of the three nematode species were significantly lower in the drier years of 1985 and 1986 than in 1984. Nematode populations were greater at the lower soil depths in the fall than in the spring or summer. PMID:19277352

  1. Host Suitability of the Olive Cultivars Arbequina and Picual for Plant-Parasitic Nematodes

    PubMed Central

    Nico, A. I.; Jiménez-Díaz, R. M.; Castillo, P.

    2003-01-01

    Host suitability of olive cultivars Arbequina and Picual to several plant-parasitic nematodes was studied under controlled conditions. Arbequina and Picual were not suitable hosts for the root-lesion nematodes Pratylenchus fallax, P. thornei, and Zygotylenchus guevarai. However, the ring nematode Mesocriconema xenoplax and the spiral nematodes Helicotylenchus digonicus and H. pseudorobustus reproduced on both olive cultivars. The potential of Meloidogyne arenaria race 2, M. incognita race 1, and M. javanica, as well as P. vulnus and P. penetrans to damage olive cultivars, was also assessed. Picual planting stocks infected by root-knot nematodes showed a distinct yellowing affecting the uppermost leaves, followed by a partial defoliation. Symptoms were more severe on M. arenaria and M. javanica-infected plants than on M. incognita-infected plants. Inoculation of plants with 15,000 eggs + second-stage juveniles/pot of these Meloidogyne spp. suppressed the main height of shoot and number of nodes of Arbequina, but not Picual. Infection by each of the two lesion nematodes (5,000 nematodes/pot) or by each of the three Meloidogyne spp. suppressed (P < 0.05) the main stem diameter of both cultivars. On Arbequina, the reproduction rate of Meloidogyne spp. was higher (P < 0.05) than that of Pratylenchus spp.; on Picual, Pratylenchus spp. reproduction was higher (P < 0.05) than that of Meloidogyne spp. PMID:19265971

  2. Exosomes secreted by nematode parasites transfer small RNAs to mammalian cells and modulate innate immunity.

    PubMed

    Buck, Amy H; Coakley, Gillian; Simbari, Fabio; McSorley, Henry J; Quintana, Juan F; Le Bihan, Thierry; Kumar, Sujai; Abreu-Goodger, Cei; Lear, Marissa; Harcus, Yvonne; Ceroni, Alessandro; Babayan, Simon A; Blaxter, Mark; Ivens, Alasdair; Maizels, Rick M

    2014-11-25

    In mammalian systems RNA can move between cells via vesicles. Here we demonstrate that the gastrointestinal nematode Heligmosomoides polygyrus, which infects mice, secretes vesicles containing microRNAs (miRNAs) and Y RNAs as well as a nematode Argonaute protein. These vesicles are of intestinal origin and are enriched for homologues of mammalian exosome proteins. Administration of the nematode exosomes to mice suppresses Type 2 innate responses and eosinophilia induced by the allergen Alternaria. Microarray analysis of mouse cells incubated with nematode exosomes in vitro identifies Il33r and Dusp1 as suppressed genes, and Dusp1 can be repressed by nematode miRNAs based on a reporter assay. We further identify miRNAs from the filarial nematode Litomosoides sigmodontis in the serum of infected mice, suggesting that miRNA secretion into host tissues is conserved among parasitic nematodes. These results reveal exosomes as another mechanism by which helminths manipulate their hosts and provide a mechanistic framework for RNA transfer between animal species.

  3. [Non-indigenous and non-specific parasitic nematodes--the background and the consequences].

    PubMed

    Okulewicz, Anna

    2009-01-01

    Introduction of the host is the main reason behind introduction of the parasite, e. g., nematodes. The introduction of the Japanese eel (Anguilla japonica) in Europe in the 1980s resulted in expansion of the swimbladder nematode Anguillicola crassus which soon invaded not only populations of the European eel (A. anguilla), but also other local fish. The raccoon (Procyon lotor) is native to North America. It is the specific host of Strongyloides procyonis and Baylisascaris procyonis. More than 90 species of wild and domestical bird and mammal species, including humans, have been infected with B. procyonis larvae. The larvae enter various organs of paratenic hosts, particularly the central nervous system and eye, causing severe diseases and death. Asthworthius sidemi--a blood-succking, abomasal nematode, a specific parasite of the Asiatic sika deer (Cervus nippon) and sambar deer (C. unicolor)--was first introduced with its hosts into countries adjacent to Poland. A. sidemi is especially dangerous to the European bison (Bison bonasus) which is its new host. The bison populations, in both Białowieza Primaeval Forest and the Bieszczady Mts, sometimes show a 100% prevalence and mass infection intensity. Imported animals, sold in pet shops or available from private breeding firms, often carry non-native parasites. For example, the red-eared tortoise (Trachemys scripta elegans) and Afgan tortoise (Agrionemys horsfieldii) carry nematodes Angusticaecum holopterum, Tachygonetria lobata and T. robusta. Migratory birds in their wintering grounds are often infected with parasites which are usually not constant components of the native fauna, but sometimes nematodes could find a suitable conditions to complete their life cycle. E.g. Cyathosoma microspiculum, species specific to cormorants (Phalacrocorax carbo) and previously recorded only from Asia and the Asian-European boudary, was able complete the life cycle in Poland. The increasingly frequent travels to countries with

  4. Managing Plant-Parasitic Nematodes in Established Red Raspberry Fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy and phytotoxicity of post-plant treatments to control root lesion [Pratylenchus penetrans (Cobb), Chitwood & Otiefa] and dagger (Xiphinema bakeri Williams) nematodes in red raspberry (Rubus idaeus L.) were evaluated in four field studies conducted over three years. Spring spray applicat...

  5. Rooting out Defense Mechanisms in Wheat against Plant Parasitic Nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root-lesion nematodes (Pratylenchus spp.) are soil borne pathogens of many important agricultural crops including wheat. Pratylenchus invade root cells and feed using a stylet, resulting in cell death. Common signs of Pratylenchus damage are root lesions, girdling, and lack of lateral branching. ...

  6. Cellulose binding protein from the parasitic nematode Heterodera schachtii interacts with Arabidopsis pectin methylesterase: cooperative cell wall modification during parasitism.

    PubMed

    Hewezi, Tarek; Howe, Peter; Maier, Tom R; Hussey, Richard S; Mitchum, Melissa Goellner; Davis, Eric L; Baum, Thomas J

    2008-11-01

    Plant-parasitic cyst nematodes secrete a complex of cell wall-digesting enzymes, which aid in root penetration and migration. The soybean cyst nematode Heterodera glycines also produces a cellulose binding protein (Hg CBP) secretory protein. To determine the function of CBP, an orthologous cDNA clone (Hs CBP) was isolated from the sugar beet cyst nematode Heterodera schachtii, which is able to infect Arabidopsis thaliana. CBP is expressed only in the early phases of feeding cell formation and not during the migratory phase. Transgenic Arabidopsis expressing Hs CBP developed longer roots and exhibited enhanced susceptibility to H. schachtii. A yeast two-hybrid screen identified Arabidopsis pectin methylesterase protein 3 (PME3) as strongly and specifically interacting with Hs CBP. Transgenic plants overexpressing PME3 also produced longer roots and exhibited increased susceptibility to H. schachtii, while a pme3 knockout mutant showed opposite phenotypes. Moreover, CBP overexpression increases PME3 activity in planta. Localization studies support the mode of action of PME3 as a cell wall-modifying enzyme. Expression of CBP in the pme3 knockout mutant revealed that PME3 is required but not the sole mechanism for CBP overexpression phenotype. These data indicate that CBP directly interacts with PME3 thereby activating and potentially targeting this enzyme to aid cyst nematode parasitism.

  7. microRNAs: a role in drug resistance in parasitic nematodes?

    PubMed

    Devaney, Eileen; Winter, Alan D; Britton, Collette

    2010-09-01

    Drug resistance in parasitic nematodes is an increasing problem worldwide, with resistance reported to all three commonly used classes of anthelmintics. Most studies to date have sought to correlate the resistant phenotype with genotypic changes in putative target molecules. Although this approach has identified mutations in several relevant genes, resistance might result from a complex interaction of different factors. Here we propose an alternative mechanism underlying the development of drug resistance based on functional differences in microRNA activity in resistant parasites. microRNAs play an important role in resistance to chemotherapeutic agents in many tumour cells and here we discuss whether they might also be involved in anthelmintic resistance in parasitic nematodes.

  8. Multiple lateral gene transfers and duplications have promoted plant parasitism ability in nematodes

    PubMed Central

    Danchin, Etienne G. J.; Rosso, Marie-Noëlle; Vieira, Paulo; de Almeida-Engler, Janice; Coutinho, Pedro M.; Henrissat, Bernard; Abad, Pierre

    2010-01-01

    Lateral gene transfer from prokaryotes to animals is poorly understood, and the scarce documented examples generally concern genes of uncharacterized role in the receiver organism. In contrast, in plant-parasitic nematodes, several genes, usually not found in animals and similar to bacterial homologs, play essential roles for successful parasitism. Many of these encode plant cell wall-degrading enzymes that constitute an unprecedented arsenal in animals in terms of both abundance and diversity. Here we report that independent lateral gene transfers from different bacteria, followed by gene duplications and early gain of introns, have shaped this repertoire. We also show protein immunolocalization data that suggest additional roles for some of these cell wall-degrading enzymes in the late stages of these parasites’ life cycle. Multiple functional acquisitions of exogenous genes that provide selective advantage were probably crucial for the emergence and proficiency of plant parasitism in nematodes. PMID:20876108

  9. RNA interference in plant parasitic nematodes: a summary of the current status.

    PubMed

    Lilley, C J; Davies, L J; Urwin, P E

    2012-04-01

    SUMMARYRNA interference (RNAi) has emerged as an invaluable gene-silencing tool for functional analysis in a wide variety of organisms, particularly the free-living model nematode Caenorhabditis elegans. An increasing number of studies have now described its application to plant parasitic nematodes. Genes expressed in a range of cell types are silenced when nematodes take up double stranded RNA (dsRNA) or short interfering RNAs (siRNAs) that elicit a systemic RNAi response. Despite many successful reports, there is still poor understanding of the range of factors that influence optimal gene silencing. Recent in vitro studies have highlighted significant variations in the RNAi phenotype that can occur with different dsRNA concentrations, construct size and duration of soaking. Discrepancies in methodology thwart efforts to reliably compare the efficacy of RNAi between different nematodes or target tissues. Nevertheless, RNAi has become an established experimental tool for plant parasitic nematodes and also offers the prospect of being developed into a novel control strategy when delivered from transgenic plants. PMID:22217302

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

    PubMed

    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.

  11. Nematodes of the genus Subulura (Subuluridae) parasitizing Coturnix (Galliformes).

    PubMed

    Barus, V; Sonin, M D

    1980-01-01

    Two nematode species of the genus Subulura, S. skrjabini and S. brumpti, have been recovered from Coturnix coturnix (a detailed redescription of the former is attached). The synonymy, geographic distribution and some morphological and metrical characters of these species are discussed. S. noctuae gallinae Semenov, 1926 and S. strongylina sensu López-Neyra (1945) are tentatively regarded as synonyms of S. differens (Sonsino, 1890).

  12. Plant-parasitic Nematodes Associated with Cotton in Florida

    PubMed Central

    Kinlock, R. A.; Sprenkel, R. K.

    1994-01-01

    A sampling of 15% of the cotton hectarage in each Florida county was assayed for nematodes and soil particle components following the 1990 harvest. The distribution of juveniles of Meloidogyne spp., which were found in 61% of the 178 fields sampled statewide, was not influenced by soil type. Rotylenchulus reniformis was more prevalent in the heavier soils and occurred in 15% of the sampled fields. In fields with concomitant infestations (9% of the sampled fields), densities of root-knot juveniles per 10 cm³ soil wer e negatively related to those of reniform nematodes (R² =-0.32; P < 0.02; df = 14). Gall ratings of cotton plants, assayed in sampled soils, were positively related to the densities of root-knot juveniles per 100 cm³ soil (R² = 0.23; P < 0.01; df = 175). Other nematode genera and their frequency of occurrence were Helicotylenchus (76%), Paratrichodorus (57%), Criconemella (53%), Pratylenchus (42%), Xiphinema (7%), Heterodera (2%), and Hoplolaimus (1%). PMID:19279958

  13. Genomic evidence for plant-parasitic nematodes as the earliest Wolbachia hosts

    PubMed Central

    Brown, Amanda M. V.; Wasala, Sulochana K.; Howe, Dana K.; Peetz, Amy B.; Zasada, Inga A.; Denver, Dee R.

    2016-01-01

    Wolbachia, one of the most widespread endosymbionts, is a target for biological control of mosquito-borne diseases (malaria and dengue virus), and antibiotic elimination of infectious filarial nematodes. We sequenced and analyzed the genome of a new Wolbachia strain (wPpe) in the plant-parasitic nematode Pratylenchus penetrans. Phylogenomic analyses placed wPpe as the earliest diverging Wolbachia, suggesting two evolutionary invasions into nematodes. The next branches comprised strains in sap-feeding insects, suggesting Wolbachia may have first evolved as a nutritional mutualist. Genome size, protein content, %GC, and repetitive DNA allied wPpe with mutualistic Wolbachia, whereas gene repertoire analyses placed it between parasite (A, B) and mutualist (C, D, F) groups. Conservation of iron metabolism genes across Wolbachia suggests iron homeostasis as a potential factor in its success. This study enhances our understanding of this globally pandemic endosymbiont, highlighting genetic patterns associated with host changes. Combined with future work on this strain, these genomic data could help provide potential new targets for plant-parasitic nematode control. PMID:27734894

  14. Transcript analysis of parasitic females of the sedentary semi-endoparasitic nematode Rotylenchulus reniformis.

    PubMed

    Wubben, Martin J; Callahan, Franklin E; Scheffler, Brian S

    2010-07-01

    Rotylenchulus reniformis, the reniform nematode, is a sedentary semi-endoparasitic nematode capable of infecting >300 plant species, including a large number of crops such as cotton, soybean, and pineapple. In contrast to other economically important plant-parasitic nematodes, molecular genetic data regarding the R. reniformis transcriptome is virtually nonexistant. Herein, we present a survey of R. reniformis ESTs that were sequenced from a sedentary parasitic female cDNA library. Cluster analysis of 2004 high quality ESTs produced 123 contigs and 508 singletons for a total of 631 R. reniformis unigenes. BLASTX analyses revealed that 39% of all unigenes showed similarity to known proteins (Eparasitism genes were identified and included beta-1,4-endoglucanase, fatty acid- and retinol-binding proteins, and an esophageal gland cell-specific gene from Heterodera glycines. Furthermore, a putative ortholog of an enzyme involved in thiamin biosynthesis, thought to exist solely in prokaryotes, fungi, and plants, was identified. Lastly, 114 R. reniformis unigenes orthologous to RNAi-lethal Caenorhabditis elegans genes were discovered. The work described here offers a glimpse into the transcriptome of a sedentary semi-endoparasitic nematode which (i) provides the transcript sequence data necessary for investigating engineered resistance against R. reniformis and (ii) hints at the existance of a thiamin biosynthesis pathway in an animal. PMID:20346373

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

    PubMed Central

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

    2003-01-01

    Pasteuria spp. include endospore-forming bacterial pathogens of cladoceran crustaceans and plant-parasitic nematodes. Propagation of these nematode pathogens requires attachment of soilborne endospores to nematode hosts, infection, growth, sporulation, and release of endospores to repeat the cycle of infection and propagation. The ability of these bacteria to suppress the levels of plant-parasitic nematodes in the field has made them particularly promising candidates for biocontrol of nematode diseases of plants. Genes encoding 16S ribosomal RNA have been sequenced for the cladoceran (water flea) parasite and type species, Pasteuria ramosa, and for Pasteuria spp. isolated from root-knot (Meloidogyne arenaria race 1 and Meloidogyne sp.), soybean cyst (Heterodera glycines), and sting (Belonolaimus longicaudatus) nematodes. These have provided a phylogenetic basis for their designation to a distinct clade within the family Alicyclobacillaceae of the gram-positive endospore-forming bacteria. Two apparent biotypes of P. penetrans demonstrating a host preference for different Meloidogyne spp. showed identical 16S rDNA sequences, suggesting host-recognition evolves within a given species. The sequences of genes encoding sporulation transcription factors, sigE and sigF, from P. penetrans biotype P-20 show different phylogenetic relationships to other endospore-forming bacteria, supporting their application to further discriminate Pasteuria spp. and biotypes. Distribution of an adhesin-associated epitope on polypeptides from different Pasteuria isolates provides an immunochemical approach to differentiate species and biotypes with specific host preferences. Application of bioinformatics to genomic data, as well as further characterization of the biochemical basis for host recognition, will facilitate development of Pasteuria spp. as benign alternatives to chemical nematicides. PMID:19265995

  16. Genomic Mechanisms Accounting for the Adaptation to Parasitism in Nematode-Trapping Fungi

    PubMed Central

    Meerupati, Tejashwari; Andersson, Karl-Magnus; Friman, Eva; Kumar, Dharmendra; Tunlid, Anders; Ahrén, Dag

    2013-01-01

    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 of RIP activity

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

    PubMed

    Meerupati, Tejashwari; Andersson, Karl-Magnus; Friman, Eva; Kumar, Dharmendra; Tunlid, Anders; Ahrén, Dag

    2013-11-01

    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 of RIP activity

  18. Genetic identification of five strongyle nematode parasites in wild african elephants (Loxodonta africana).

    PubMed

    McLean, E R; Kinsella, J M; Chiyo, P; Obanda, V; Moss, C; Archie, E A

    2012-07-01

    African savannah elephants (Loxodonta africana) are an ecologically and economically important species in many African habitats. However, despite the importance of elephants, research on their parasites is limited, especially in wild populations. Currently, we lack genetic tools to identify elephant parasites. We present genetic markers from ribosomal DNA (rDNA) and mitochondrial DNA (mtDNA) to identify five elephant-specific nematode parasites in the family Strongylidae: Murshidia linstowi, Murshidia longicaudata, Murshidia africana, Quilonia africana, and Khalilia sameera. We collected adult nematodes from feces deposited by wild elephants living in Amboseli National Park, Kenya. Using both morphologic and genetic techniques, we found that the internal transcribed spacer (ITS) region in rDNA provides a reliable marker to distinguish these species of strongyles. We found no evidence for cryptic genetic species within these morphologic species according to the cox-1 region of mtDNA. Levels of genetic diversity in strongyles from elephants were consistent with the genetic diversity seen within other strongyle species. We anticipate that these results will be a useful tool for identifying gastrointestinal nematode parasites in elephants.

  19. The Transcriptome of Nacobbus aberrans Reveals Insights into the Evolution of Sedentary Endoparasitism in Plant-Parasitic Nematodes

    PubMed Central

    Eves-van den Akker, Sebastian; Lilley, Catherine J.; Danchin, Etienne G. J.; Rancurel, Corinne; Cock, Peter J. A.; Urwin, Peter E.; Jones, John T.

    2014-01-01

    Within the phylum Nematoda, plant-parasitism is hypothesized to have arisen independently on at least four occasions. The most economically damaging plant-parasitic nematode species, and consequently the most widely studied, are those that feed as they migrate destructively through host roots causing necrotic lesions (migratory endoparasites) and those that modify host root tissue to create a nutrient sink from which they feed (sedentary endoparasites). The false root-knot nematode Nacobbus aberrans is the only known species to have both migratory endoparasitic and sedentary endoparasitic stages within its life cycle. Moreover, its sedentary stage appears to have characteristics of both the root-knot and the cyst nematodes. We present the first large-scale genetic resource of any false-root knot nematode species. We use RNAseq to describe relative abundance changes in all expressed genes across the life cycle to provide interesting insights into the biology of this nematode as it transitions between modes of parasitism. A multigene phylogenetic analysis of N. aberrans with respect to plant-parasitic nematodes of all groups confirms its proximity to both cyst and root-knot nematodes. We present a transcriptome-wide analysis of both lateral gene transfer events and the effector complement. Comparing parasitism genes of typical root-knot and cyst nematodes to those of N. aberrans has revealed interesting similarities. Importantly, genes that were believed to be either cyst nematode, or root-knot nematode, “specific” have both been identified in N. aberrans. Our results provide insights into the characteristics of a common ancestor and the evolution of sedentary endoparasitism of plants by nematodes. PMID:25123114

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

    PubMed Central

    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

  1. Chorismate mutase: an alternatively spliced parasitism gene and a diagnostic marker for three important Globodera nematode species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chorismate mutase gene is widely distributed in both cyst and root-knot nematode species and believed to play a critical role in nematode parasitism. In this study, we cloned a new chorismate mutase gene (Gt-cm-1) from Globodera tabacum and further characterized the gene structure in both G. tab...

  2. Synergistic interaction of CLAVATA1, CLAVATA2, and RECEPTOR-LIKE PROTEIN KINASE 2 in cyst nematode parasitism of Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant-parasitic cyst nematodes secrete CLAVATA3 (CLV3)/ENDOSPERM SURROUNDING REGION (ESR) (CLE)-like effector proteins. These proteins act as ligand mimics of plant CLE peptides and are required for successful nematode infection. Previously, we showed that CLV2 and CORYNE (CRN), a heterodimer recept...

  3. Plant-parasitic Nematodes Associated with Cherry Rootstocks in Michigan

    PubMed Central

    Melakeberhan, H.; Bird, G. W.; Perry, R.

    1994-01-01

    In two field trials, 10-year-old sweet and tart cherry rooted on 'Mazzard', 'Mahaleb', 'MXM 2', 'MXM 14', 'MXM 39', 'MXM 60', 'MXM 97', and 'Colt' showed 10-203 Pratylenchus penetrans per g fresh root from all tart rootstocks, and up to 46 Pratylenchus, Criconemella, and Xiphinema spp. per 100 cm³ soil. Infestation of soil containing 1-year-old Mazzard, Mahaleb, MXM 60, 'GI148-1', and 'G1148-8' with 625/100 cm³ soil of either P. penetrans or C. xenoplax resulting in final nematode population densities of 123-486 and 451-2,496/g fresh root plus 100 cm³ soil, respectively, and had little effect on plant height or dry weight after 157 days in a greenhouse. Population densities of neither nematode differed among the five rootstocks. In a second greenhouse experiment, soil containing the same rootstocks was infested with P. penetrans (1,250/100 cm³ soil), maintained for 8 months in a greenhouse, 4 months in a cold room (2-4 C), and 3 additional months in a greenhouse. The number of P. penetrans recovered at the end of 475 days was approximately 10% of those recovered in the first experiment, probably due to the cold treatment. The ability of P. penetrans and C. xenoplax to infect the cherry rootstocks may be of concern in cherry management programs. PMID:19279962

  4. Host age, sex, and reproductive seasonality affect nematode parasitism in wild Japanese macaques.

    PubMed

    MacIntosh, Andrew J J; Hernandez, Alexander D; Huffman, Michael A

    2010-10-01

    Parasites are characteristically aggregated within hosts, but identifying the mechanisms underlying such aggregation can be difficult in wildlife populations. We examined the influence of host age and sex over an annual cycle on the eggs per gram of feces (EPG) of nematode parasites infecting wild Japanese macaques (Macaca fuscata yakui) on Yakushima Island. Five species of nematode were recorded from 434 fecal samples collected from an age-structured group of 50 individually recognizable macaques. All parasites exhibited aggregated EPG distributions. The age-infection profiles of all three directly transmitted species (Oesophagostomum aculeatum, Strongyloides fuelleborni, and Trichuris trichiura) exhibited convex curves, but concavity better characterized the age-infection curves of the two trophically transmitted species (Streptopharagus pigmentatus and Gongylonema pulchrum). There was a male bias in EPG and prevalence of infection with directly transmitted species, except in the prevalence of O. aculeatum, and no sex bias in the other parasites. Infection with O. aculeatum showed a female bias in prevalence among young adults, and additional interactions with sex and seasonality show higher EPG values in males during the mating season (fall) but in females during the birth season (spring). These patterns suggest that an immunosuppressive role by reproductive hormones may be regulating direct, but not indirect, life-cycle parasites. Exposure at an early age may trigger an immune response that affects all nematodes, but trophically transmitted species appear to accumulate thereafter. Although it is difficult to discern clear mechanistic explanations for parasite distributions in wildlife populations, it is critical to begin examining these patterns in host species that are increasingly endangered by anthropogenic threats.

  5. A parasitic nematode releases cytokinin that controls cell division and orchestrates feeding site formation in host plants

    PubMed Central

    Siddique, Shahid; Radakovic, Zoran S.; De La Torre, Carola M.; Chronis, Demosthenis; Novák, Ondřej; Ramireddy, Eswarayya; Holbein, Julia; Matera, Christiane; Hütten, Marion; Gutbrod, Philipp; Anjam, Muhammad Shahzad; Rozanska, Elzbieta; Habash, Samer; Elashry, Abdelnaser; Sobczak, Miroslaw; Kakimoto, Tatsuo; Strnad, Miroslav; Schmülling, Thomas; Mitchum, Melissa G.; Grundler, Florian M. W.

    2015-01-01

    Sedentary plant-parasitic cyst nematodes are biotrophs that cause significant losses in agriculture. Parasitism is based on modifications of host root cells that lead to the formation of a hypermetabolic feeding site (a syncytium) from which nematodes withdraw nutrients. The host cell cycle is activated in an initial cell selected by the nematode for feeding, followed by activation of neighboring cells and subsequent expansion of feeding site through fusion of hundreds of cells. It is generally assumed that nematodes manipulate production and signaling of the plant hormone cytokinin to activate cell division. In fact, nematodes have been shown to produce cytokinin in vitro; however, whether the hormone is secreted into host plants and plays a role in parasitism remained unknown. Here, we analyzed the spatiotemporal activation of cytokinin signaling during interaction between the cyst nematode, Heterodera schachtii, and Arabidopsis using cytokinin-responsive promoter:reporter lines. Our results showed that cytokinin signaling is activated not only in the syncytium but also in neighboring cells to be incorporated into syncytium. An analysis of nematode infection on mutants that are deficient in cytokinin or cytokinin signaling revealed a significant decrease in susceptibility of these plants to nematodes. Further, we identified a cytokinin-synthesizing isopentenyltransferase gene in H. schachtii and show that silencing of this gene in nematodes leads to a significant decrease in virulence due to a reduced expansion of feeding sites. Our findings demonstrate the ability of a plant-parasitic nematode to synthesize a functional plant hormone to manipulate the host system and establish a long-term parasitic interaction. PMID:26417108

  6. A parasitic nematode releases cytokinin that controls cell division and orchestrates feeding site formation in host plants.

    PubMed

    Siddique, Shahid; Radakovic, Zoran S; De La Torre, Carola M; Chronis, Demosthenis; Novák, Ondřej; Ramireddy, Eswarayya; Holbein, Julia; Matera, Christiane; Hütten, Marion; Gutbrod, Philipp; Anjam, Muhammad Shahzad; Rozanska, Elzbieta; Habash, Samer; Elashry, Abdelnaser; Sobczak, Miroslaw; Kakimoto, Tatsuo; Strnad, Miroslav; Schmülling, Thomas; Mitchum, Melissa G; Grundler, Florian M W

    2015-10-13

    Sedentary plant-parasitic cyst nematodes are biotrophs that cause significant losses in agriculture. Parasitism is based on modifications of host root cells that lead to the formation of a hypermetabolic feeding site (a syncytium) from which nematodes withdraw nutrients. The host cell cycle is activated in an initial cell selected by the nematode for feeding, followed by activation of neighboring cells and subsequent expansion of feeding site through fusion of hundreds of cells. It is generally assumed that nematodes manipulate production and signaling of the plant hormone cytokinin to activate cell division. In fact, nematodes have been shown to produce cytokinin in vitro; however, whether the hormone is secreted into host plants and plays a role in parasitism remained unknown. Here, we analyzed the spatiotemporal activation of cytokinin signaling during interaction between the cyst nematode, Heterodera schachtii, and Arabidopsis using cytokinin-responsive promoter:reporter lines. Our results showed that cytokinin signaling is activated not only in the syncytium but also in neighboring cells to be incorporated into syncytium. An analysis of nematode infection on mutants that are deficient in cytokinin or cytokinin signaling revealed a significant decrease in susceptibility of these plants to nematodes. Further, we identified a cytokinin-synthesizing isopentenyltransferase gene in H. schachtii and show that silencing of this gene in nematodes leads to a significant decrease in virulence due to a reduced expansion of feeding sites. Our findings demonstrate the ability of a plant-parasitic nematode to synthesize a functional plant hormone to manipulate the host system and establish a long-term parasitic interaction.

  7. The Biochemistry of Haemonchus contortus and Other Parasitic Nematodes.

    PubMed

    Harder, A

    2016-01-01

    Different life cycle stages of Haemonchus contortus adapt to different ecosystems. This adaptation is accompanied by alterations in gene transcription and expression associated with the energy, amino acid, nitrogen, lipid and/or nucleic acid metabolism of the respective stages. For example, the aerobic metabolism of larvae depends on an efficient citric acid cycle, whereas the anaerobic metabolism of adults requires glycolysis, resulting in the production of volatile fatty acids, such as acetic acid and propionic acid. There are only few anthelmintics targeting nematode energy metabolism. In addition, H. contortus has reduced pathways for amino acid metabolism, polyamine metabolism and nitrogen excretion pathways. Moreover, nucleic acid metabolism comprising purine and pyrimidine salvage pathways as well as lipid metabolism are reduced. In addition, nematodes possess a particular composition of their cuticle. Energy production of adult worms is mainly linked to egg production and complex regulation of the neuromuscular system in both females and males. In this context, microtubules consisting of α- and β-tubulin heterodimers play a crucial role in the presynaptic vesicle transport. Due to the significant distinction of its quarternary structure in nematodes in comparison to other organisms, β-tubulin was identified as a major target for benzimidazoles used for anthelmintic treatment. Concerning the function of the neuromuscular system, acetylcholine, a ligand of the nicotinic acetylcholine receptor (nAChR), is the major excitatory neurotransmitter in H. contortus. In contrast, glutamate-gated chloride channels, calcium- and voltage-dependent potassium channels as well as γ-aminobutyric acid (GABA)A and its receptors act as inhibitory neurotransmitters and thus opponents to nAChR. For example, the calcium- and voltage-dependent potassium channel SLO-1 is an important target of emodepside, which is involved in the sensitive regulation of activatory and

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

    PubMed Central

    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 occasionally reached maturity. PMID:19279854

  9. Evidence for gene flow in parasitic nematodes between two host species of shrews.

    PubMed

    Brant, Sara V; Ortí, Guillermo

    2003-10-01

    We describe the genetic structure of populations of the intestinal nematode Longistriata caudabullata (Trichostrongyloidea: Heligmosomidae), a common parasite of short-tailed shrews (genus Blarina, Insectivora: Soricidae). Parasites and hosts were collected from a transect across a contact zone between two species of hosts, Blarina brevicauda and B. hylophaga, in central North America. An 800-base pairs (bp) fragment of the ND4 mitochondrial DNA (mtDNA) gene was sequenced for 28 worms and a 783-bp fragment of the mtDNA control region was analysed for 16 shrews. Phylogenetic analyses of mtDNA sequences revealed reciprocal monophyly for the shrew species, concordant with morphological diagnosis, and supported the idea that the transect cuts through a secondary contact zone between well-differentiated B. brevicauda and B. hylophaga. In contrast to this pattern, the parasitic nematode mtDNA phylogeny was not subdivided according to host affiliation. Genealogical discordance between parasite and host phylogenies suggests extensive gene flow among parasites across the host species boundary. PMID:12969487

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

    PubMed

    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.

  11. Distribution and Prevalence of Parasitic Nematodes of Cowpea (Vigna unguiculata) in Burkina Faso.

    PubMed

    Sawadogo, A; Thio, B; Kiemde, S; Drabo, I; Dabire, C; Ouedraogo, J; Mullens, T R; Ehlers, J D; Roberts, P A

    2009-06-01

    A comprehensive survey of the plant parasitic nematodes associated with cowpea (Vigna unguiculata) production fields was carried out in the three primary agro-climatic zones of Burkina Faso in West Africa. Across the three zones, a total of 109 samples were collected from the farms of 32 villages to provide a representative coverage of the cowpea production areas. Samples of rhizosphere soil and samples of roots from actively growing cowpea plants were collected during mid- to late-season. Twelve plant-parasitic nematode genera were identified, of which six appeared to have significant parasitic potential on cowpea based on their frequency and abundance. These included Helicotylenchus, Meloidogyne, Pratylenchus, Scutellonema, Telotylenchus, and Tylenchorhynchus. Criconemella and Rotylenchulus also had significant levels of abundance and frequency, respectively. Of the primary genera, Meloidogyne, Pratylenchus, and Scutellonema contained species which are known or suspected to cause losses of cowpea yield in other parts of the world. According to the prevalence and distribution of these genera in Burkina Faso, their potential for damage to cowpea increased from the dry Sahelian semi-desert zone in the north (annual rainfall < 600 mm/year), through the north-central Soudanian zone (annual rainfall of 600-800 mm/year), to the wet Soudanian zone (annual rainfall ≥ 1000 mm) in the more humid south-western region of the country. This distribution trend was particularly apparent for the endoparasitic nematode Meloidogyne and the migratory endoparasite Pratylenchus. PMID:22661784

  12. New plant-parasitic nematode from the mostly mycophagous genus Bursaphelenchus discovered inside figs in Japan.

    PubMed

    Kanzaki, Natsumi; Tanaka, Ryusei; Giblin-Davis, Robin M; Davies, Kerrie A

    2014-01-01

    A new nematode species, Bursaphelenchus sycophilus n. sp. is described. The species was found in syconia of a fig species, Ficus variegata during a field survey of fig-associated nematodes in Japan. Because it has a well-developed stylet and pharyngeal glands, the species is considered an obligate plant parasite, and is easily distinguished from all other fungal-feeding species in the genus based upon these characters. Although B. sycophilus n. sp. shares an important typological character, male spicule possessing a strongly recurved condylus, with the "B. eremus group" and the "B. leoni group" of the genus, it was inferred to be monophyletic with the "B. fungivorus group". The uniquely shaped stylet and well-developed pharyngeal glands is reminiscent of the fig-floret parasitic but paraphyletic assemblage of "Schistonchus". Thus, these morphological characters appear to be an extreme example of convergent evolution in the nematode family, Aphelenchoididae, inside figs. Other characters shared by the new species and its close relatives, i.e., lack of ventral P1 male genital papilla, female vulval flap, and papilla-shaped P4 genital papillae in males, corroborate the molecular phylogenetic inference. The unique biological character of obligate plant parasitism and highly derived appearance of the ingestive organs of Bursaphelenchus sycophilus n. sp. expands our knowledge of the potential morphological, physiological and developmental plasticity of the genus Bursaphelenchus.

  13. Optimizing culture conditions for free-living stages of the nematode parasite Strongyloides ratti.

    PubMed

    Dulovic, Alex; Puller, Vadim; Streit, Adrian

    2016-09-01

    The rat parasitic nematode Strongyloides ratti (S. ratti) has recently emerged as a model system for various aspects of parasite biology and evolution. In addition to parasitic parthenogenetic females, this species can also form facultative free-living generations of sexually reproducing adults. These free-living worms are bacteriovorous and grow very well when cultured in the feces of their host. However, in fecal cultures the worms are rather difficult to find for observation and experimental manipulation. Therefore, it has also been attempted to raise S. ratti on Nematode Growth Media (NGM) plates with Escherichia coli OP50 as food, exactly as described for the model nematode Caenorhabditis elegans. Whilst worms did grow on these plates, their longevity and reproductive output compared to fecal cultures were dramatically reduced. In order to improve the culture success we tested other plates occasionally used for C. elegans and, starting from the best performing one, systematically varied the plate composition, the temperature and the food in order to further optimize the conditions. Here we present a plate culturing protocol for free-living stages of S. ratti with strongly improved reproductive success and longevity. PMID:27334397

  14. New Plant-Parasitic Nematode from the Mostly Mycophagous Genus Bursaphelenchus Discovered inside Figs in Japan

    PubMed Central

    Kanzaki, Natsumi; Tanaka, Ryusei; Giblin-Davis, Robin M.; Davies, Kerrie A.

    2014-01-01

    A new nematode species, Bursaphelenchus sycophilus n. sp. is described. The species was found in syconia of a fig species, Ficus variegata during a field survey of fig-associated nematodes in Japan. Because it has a well-developed stylet and pharyngeal glands, the species is considered an obligate plant parasite, and is easily distinguished from all other fungal-feeding species in the genus based upon these characters. Although B. sycophilus n. sp. shares an important typological character, male spicule possessing a strongly recurved condylus, with the “B. eremus group” and the “B. leoni group” of the genus, it was inferred to be monophyletic with the “B. fungivorus group”. The uniquely shaped stylet and well-developed pharyngeal glands is reminiscent of the fig-floret parasitic but paraphyletic assemblage of “Schistonchus”. Thus, these morphological characters appear to be an extreme example of convergent evolution in the nematode family, Aphelenchoididae, inside figs. Other characters shared by the new species and its close relatives, i.e., lack of ventral P1 male genital papilla, female vulval flap, and papilla-shaped P4 genital papillae in males, corroborate the molecular phylogenetic inference. The unique biological character of obligate plant parasitism and highly derived appearance of the ingestive organs of Bursaphelenchus sycophilus n. sp. expands our knowledge of the potential morphological, physiological and developmental plasticity of the genus Bursaphelenchus. PMID:24940595

  15. Distribution and Prevalence of Parasitic Nematodes of Cowpea (Vigna unguiculata) in Burkina Faso.

    PubMed

    Sawadogo, A; Thio, B; Kiemde, S; Drabo, I; Dabire, C; Ouedraogo, J; Mullens, T R; Ehlers, J D; Roberts, P A

    2009-06-01

    A comprehensive survey of the plant parasitic nematodes associated with cowpea (Vigna unguiculata) production fields was carried out in the three primary agro-climatic zones of Burkina Faso in West Africa. Across the three zones, a total of 109 samples were collected from the farms of 32 villages to provide a representative coverage of the cowpea production areas. Samples of rhizosphere soil and samples of roots from actively growing cowpea plants were collected during mid- to late-season. Twelve plant-parasitic nematode genera were identified, of which six appeared to have significant parasitic potential on cowpea based on their frequency and abundance. These included Helicotylenchus, Meloidogyne, Pratylenchus, Scutellonema, Telotylenchus, and Tylenchorhynchus. Criconemella and Rotylenchulus also had significant levels of abundance and frequency, respectively. Of the primary genera, Meloidogyne, Pratylenchus, and Scutellonema contained species which are known or suspected to cause losses of cowpea yield in other parts of the world. According to the prevalence and distribution of these genera in Burkina Faso, their potential for damage to cowpea increased from the dry Sahelian semi-desert zone in the north (annual rainfall < 600 mm/year), through the north-central Soudanian zone (annual rainfall of 600-800 mm/year), to the wet Soudanian zone (annual rainfall ≥ 1000 mm) in the more humid south-western region of the country. This distribution trend was particularly apparent for the endoparasitic nematode Meloidogyne and the migratory endoparasite Pratylenchus.

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

    PubMed

    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.

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

    PubMed

    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.

  18. [Main evolution lines of plant parasitic nematodes of the order Aphelenchida siddiqi, 1980].

    PubMed

    Ryss, A Iu

    2007-01-01

    Phylogenic models for each aphelenchid family and phylogeny of the order Aphelenchida as a whole were developed on the base of detailed comparative morphological and bionomical analysis of the order. Bionomical and morphological characters having a phylogenetic significance were selected. Classification proposed by Hunt, 1993 was used as the starting-point of the study. Life cycles and their evolution in Aphelenchida were analyzed on the base of phylogenetic trees. It is concluded, that aphelenchid ancestors combined mycophagy, plant parasitic, and partly predaceous feeding. Relations of the primitive Aphelenchida with their symbionts developed from the spots of the fungal organic matter decomposition in the "nema- tode-fungi" associations, followed by a transition to the temporary endoparasitic habit omitting ectoparasitism. With a complication of the nematodes' life cycles, the insect vector (detritophagous or pollinator) transformed into the real insect host of the parasitic nematode in the 2-host life cycle (with the plant and insect hosts) or in the obligate 1-host entomoparasitic life cycle of the aphelenchid nematodes. Specialization of the aphelenchid life cycles to insect vectors followed two main ways. In the first way, the resistant to unfavorable environmental conditions nematode juveniles, known already for the primitive aphelenchids transformed into dispersal juveniles, and later into parasitic juveniles. In the second evolution line the dispersal function were laid on inseminated but non-gravid (not egg-producing) females. Both above-mentioned trends of parasitic specialization were arisen independently in different phylogenetic lines of the Aphelenchida. In each line of the parasitic development in different nematode families, the highly specialized ectoparasites, as well as endoparasites on insects, were formed. In the evolution of life cycle of parasitic nematodes, a tendency to decrease the body size took place. The function of dispersion shifted

  19. Serine proteases of parasitic helminths.

    PubMed

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

    2015-02-01

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

  20. Serine Proteases of Parasitic Helminths

    PubMed Central

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

    2015-01-01

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

  1. Suppression on plant-parasitic nematodes using a soil fumigation strategy based on ammonium bicarbonate and its effects on the nematode community.

    PubMed

    Su, Lanxi; Ruan, Yunze; Yang, Xiujuan; Wang, Kang; Li, Rong; Shen, Qirong

    2015-12-01

    Banana production is severely hindered by plant-parasitic nematodes in acidic, sandy soil. This study investigated the possibility of applying a novel fumigation agent based on ammonium bicarbonate as a strategy for controlling plant-parasitic nematodes under sealed conditions. Moreover, its effects on the nematode community in pot and field experiments were also measured using morphology and feeding-habit based classification and the PCR-DGGE method. Results showed that a mixture (LAB) of lime (L) and ammonium bicarbonate (AB) in suitable additive amounts (0.857 g kg(-1) of L and 0.428 g kg(-1) of AB) showed stronger nematicidal ability than did the use of AB alone or the use of ammonium hydroxide (AH) and calcium cyanamide (CC) with an equal nitrogen amount. The nematode community was altered by the different fumigants, and LAB showed an excellent plant-parasitic nematicidal ability, especially for Meloidogyne and Rotylenchulus, as revealed by morphology and feeding-habit based classification, and for Meloidogyne, as revealed by the PCR-DGGE method. Fungivores and omnivore-predators were more sensitive to the direct effects of the chemicals than bacterivores. This study explored a novel fumigation agent for controlling plant-parasitic nematodes based on LAB and provides a potential strategy to ensure the worldwide development of the banana industry.

  2. Suppression on plant-parasitic nematodes using a soil fumigation strategy based on ammonium bicarbonate and its effects on the nematode community

    PubMed Central

    Su, Lanxi; Ruan, Yunze; Yang, Xiujuan; Wang, Kang; Li, Rong; Shen, Qirong

    2015-01-01

    Banana production is severely hindered by plant-parasitic nematodes in acidic, sandy soil. This study investigated the possibility of applying a novel fumigation agent based on ammonium bicarbonate as a strategy for controlling plant-parasitic nematodes under sealed conditions. Moreover, its effects on the nematode community in pot and field experiments were also measured using morphology and feeding-habit based classification and the PCR-DGGE method. Results showed that a mixture (LAB) of lime (L) and ammonium bicarbonate (AB) in suitable additive amounts (0.857 g kg−1 of L and 0.428 g kg−1 of AB) showed stronger nematicidal ability than did the use of AB alone or the use of ammonium hydroxide (AH) and calcium cyanamide (CC) with an equal nitrogen amount. The nematode community was altered by the different fumigants, and LAB showed an excellent plant-parasitic nematicidal ability, especially for Meloidogyne and Rotylenchulus, as revealed by morphology and feeding-habit based classification, and for Meloidogyne, as revealed by the PCR-DGGE method. Fungivores and omnivore-predators were more sensitive to the direct effects of the chemicals than bacterivores. This study explored a novel fumigation agent for controlling plant-parasitic nematodes based on LAB and provides a potential strategy to ensure the worldwide development of the banana industry. PMID:26621630

  3. Suppression on plant-parasitic nematodes using a soil fumigation strategy based on ammonium bicarbonate and its effects on the nematode community.

    PubMed

    Su, Lanxi; Ruan, Yunze; Yang, Xiujuan; Wang, Kang; Li, Rong; Shen, Qirong

    2015-01-01

    Banana production is severely hindered by plant-parasitic nematodes in acidic, sandy soil. This study investigated the possibility of applying a novel fumigation agent based on ammonium bicarbonate as a strategy for controlling plant-parasitic nematodes under sealed conditions. Moreover, its effects on the nematode community in pot and field experiments were also measured using morphology and feeding-habit based classification and the PCR-DGGE method. Results showed that a mixture (LAB) of lime (L) and ammonium bicarbonate (AB) in suitable additive amounts (0.857 g kg(-1) of L and 0.428 g kg(-1) of AB) showed stronger nematicidal ability than did the use of AB alone or the use of ammonium hydroxide (AH) and calcium cyanamide (CC) with an equal nitrogen amount. The nematode community was altered by the different fumigants, and LAB showed an excellent plant-parasitic nematicidal ability, especially for Meloidogyne and Rotylenchulus, as revealed by morphology and feeding-habit based classification, and for Meloidogyne, as revealed by the PCR-DGGE method. Fungivores and omnivore-predators were more sensitive to the direct effects of the chemicals than bacterivores. This study explored a novel fumigation agent for controlling plant-parasitic nematodes based on LAB and provides a potential strategy to ensure the worldwide development of the banana industry. PMID:26621630

  4. Nicotinic acetylcholine receptors: a comparison of the nAChRs of Caenorhabditis elegans and parasitic nematodes.

    PubMed

    Holden-Dye, Lindy; Joyner, Michelle; O'Connor, Vincent; Walker, Robert J

    2013-12-01

    Nicotinic acetylcholine receptors (nAChRs) play a key role in the normal physiology of nematodes and provide an established target site for anthelmintics. The free-living nematode, Caenorhabditis elegans, has a large number of nAChR subunit genes in its genome and so provides an experimental model for testing novel anthelmintics which act at these sites. However, many parasitic nematodes lack specific genes present in C. elegans, and so care is required in extrapolating from studies using C. elegans to the situation in other nematodes. In this review the properties of C. elegans nAChRs are reviewed and compared to those of parasitic nematodes. This forms the basis for a discussion of the possible subunit composition of nAChRs from different species of parasitic nematodes. Currently our knowledge on this is largely based on studies using heterologous expression and pharmacological analysis of receptor subunits in Xenopus laevis oocytes. It is concluded that more information is required regarding the subunit composition and pharmacology of endogenous nAChRs in parasitic nematodes. PMID:23500392

  5. Vaccination with a genetically modified Brugia malayi cysteine protease inhibitor-2 reduces adult parasite numbers and affects the fertility of female worms following a subcutaneous challenge of Mongolian gerbils (Meriones unguiculatus) with B. malayi infective larvae.

    PubMed

    Arumugam, Sridhar; Wei, Junfei; Ward, Danielle; Abraham, David; Lustigman, Sara; Zhan, Bin; Klei, Thomas R

    2014-09-01

    Vaccination of Mongolian gerbils with Brugia malayi cysteine protease inhibitor-2 in which the amino acid Asn66 was mutated to Lys66 (Bm-CPI-2M) resulted in reduced parasite numbers of 48.6% and 48.0% at 42 and 90 days p.i. with B. malayi L3s. Fertility of female worms was also affected at 90 days p.i. In vitro killing of L3s observed in the presence of gerbil peritoneal exudate cells and anti-Bm-CPI-2M sera suggests antibody-dependent cell-mediated cytotoxicity as a putative protective mechanism. These observations suggest that Bm-CPI-2M is a promising prophylactic and anti-fecundity vaccine candidate.

  6. Preadult Stage Parasites and Multiple Timed Exposure to Infective Larvae Are Involved in Development of Limb Edema in Brugia malayi-Infected Indian Leaf Monkeys (Presbytis entellus)†

    PubMed Central

    Murthy, P. K.; Khan, M. A.; Rajani, H. B.; Srivastava, V. M. L.

    2002-01-01

    The pathogenesis of filarial limb edema is not known. The role of parasitological variables and parasite-mediated phenomena in the development of limb edema was investigated in the Presbytis entellus-Brugia malayi model. Infection was initiated with subcutaneous inoculation of infective third-stage larvae (L3), and the animals were reexposed to different doses of L3 at the prepatent, patent, and diminishing microfilaremia (0 to 5% of peak microfilaremia count) stages of infection. A large L3 inoculum size and repeated inoculation in the ankle region during the prepatent, patent, and diminishing microfilaremia stages of infection were found to be necessary for reproducible induction of limb edema. The preadult stage of the parasite was found to be the most potent inducer of limb edema, followed by L5 and L4. The presence of the proinflammatory cytokines tumor necrosis factor alpha, interleukin-1β, and interleukin-6 in edema fluid in the leg receiving the parasite challenge indicated that the limb edema development was due to parasite-mediated cytokine responses. The absence of bacterial infection or anti-streptolysin O titer in the edema fluid and blood indicated that bacterial infection is not necessary for the development of limb edema. PMID:12093695

  7. Nematode parasites infecting the starry batfish Halieutaea stellata (Vahl) (Lophiiformes: Ogcocephalidae) from the East and South China Sea.

    PubMed

    Li, L; Zhao, W-T; Guo, Y-N; Zhang, L-P

    2016-05-01

    The starry batfish Halieutaea stellata (Vahl) is a small, benthic fish found in Indo-West Pacific Oceans. However, our present knowledge of the helminth parasites of this fish is still fragmentary. In this study, a total of 29 fish collected from the East and South China Sea were examined to determine the prevalence, intensity and species composition of helminth parasites in H. stellata. Using morphological and molecular approaches, four species of nematodes were found parasitic in this fish host, including the adults and fourth-stage larvae of Raphidascaroides nipponensis Yamaguti 1941; adults and third-stage larvae of Raphidascaris lophii (Wu 1949), third- and fourth-stage larvae of Hysterothylacium larval type IV-A of Shamsi, Gasser & Beveridge 2013 and third-stage larvae of Hysterothylacium amoyense (Hsü 1993). Halieutaea stellata represents a new host record for the three last-named nematodes. Raphidascaroides nipponensis with the highest prevalence (82.5%) and intensity (mean = 13.5) of infection was considered as the dominant parasite species in H. stellata. The detailed morphology of the different developmental stages of the four nematode species was studied using light and scanning electron microscopy. All nematode species were also genetically characterized by sequencing and analysing the internal transcribed spacer (ITS) of the ribosomal DNA. This study provides further data on the occurrence of nematode parasites in H. stellata and also contributes to facilitate an accurate and rapid diagnosis of the infection by these little-known nematodes. PMID:25917527

  8. Nematode parasites infecting the starry batfish Halieutaea stellata (Vahl) (Lophiiformes: Ogcocephalidae) from the East and South China Sea.

    PubMed

    Li, L; Zhao, W-T; Guo, Y-N; Zhang, L-P

    2016-05-01

    The starry batfish Halieutaea stellata (Vahl) is a small, benthic fish found in Indo-West Pacific Oceans. However, our present knowledge of the helminth parasites of this fish is still fragmentary. In this study, a total of 29 fish collected from the East and South China Sea were examined to determine the prevalence, intensity and species composition of helminth parasites in H. stellata. Using morphological and molecular approaches, four species of nematodes were found parasitic in this fish host, including the adults and fourth-stage larvae of Raphidascaroides nipponensis Yamaguti 1941; adults and third-stage larvae of Raphidascaris lophii (Wu 1949), third- and fourth-stage larvae of Hysterothylacium larval type IV-A of Shamsi, Gasser & Beveridge 2013 and third-stage larvae of Hysterothylacium amoyense (Hsü 1993). Halieutaea stellata represents a new host record for the three last-named nematodes. Raphidascaroides nipponensis with the highest prevalence (82.5%) and intensity (mean = 13.5) of infection was considered as the dominant parasite species in H. stellata. The detailed morphology of the different developmental stages of the four nematode species was studied using light and scanning electron microscopy. All nematode species were also genetically characterized by sequencing and analysing the internal transcribed spacer (ITS) of the ribosomal DNA. This study provides further data on the occurrence of nematode parasites in H. stellata and also contributes to facilitate an accurate and rapid diagnosis of the infection by these little-known nematodes.

  9. Frequency and Geographical Distribution of Plant-Parasitic Nematodes on Cotton in Georgia

    PubMed Central

    Baird, R. E.; Davis, R. F.; Alt, P. J.; Mullinix, B. G.; Padgett, G. B.

    1996-01-01

    A survey was conducted to examine the geographical distribution of plant-parasitic nematodes in Georgia cotton fields. A total of 778 fields in 11 Georgia counties were sampled from 1 September through 15 December 1995. Four nematode genera parasitic on cotton were found in this survey: Meloidogyne spp., Rotylenchulus sp., Hoplolaimus sp., and Belonolaimus sp. Meloidogyne spp. was present in 9% to 56% of the fields in individual counties. Rotylenchulus sp. was found in 10 counties, Hoplolaimus sp. was found in 6 counties, and Belonolaimus sp. was found in 2 counties. From all of the samples collected for this survey, Meloidogyne spp. were found in 31% of the samples, Rotylenchulus sp. was found in 14%, Hoplolaimus sp. was found in 7%, and Belonolaimus sp. was found in 0.3%. Burke County had the greatest number of fields infested by at least one of these genera (67%) and the greatest number of fields above Georgia's action thresholds (38%). Laurens County had the fewest fields where these genera were present (13%), and only 3% of fields had nematode populations above threshold levels. Data from samples collected from cotton fields and submitted by county agents from 1993 through 1994 were compiled to provide historical information about nematode distribution and population density. The results from this survey show that the major nematodes damaging to cotton are not present in all counties in Georgia. Counties in which cotton has historically been a major crop are likely to have higher levels of Meloidogyne spp., Hoplolaimus sp., and Rotylenchulus sp. in current cotton crops. Counties in which soybean has historically been a major crop are likely to have higher levels of Hoplolaimus sp. and Rotylenchulus sp. in current cotton crops. PMID:19277192

  10. Trichinella spiralis, potential model nematode for epigenetics and its implication in metazoan parasitism.

    PubMed

    Gao, Fei; Wang, Rui; Liu, Mingyuan

    2014-01-10

    The recent discovery of DNA methylation in the nematode T.spiralis may raise the possibility of using it as a potential model organism for epigenetic studies instead of C. elegans, which is deficient in this important epigenetic modification. In contrast to the free-living nematode C. elegans, T. spiralis is a parasitic worm that possesses a complicated life cycle and undergoes a complex developmental regulation of genes. We emphasize that the differential methylomes in the different life-history stages of T. spiralis can provide insight on how DNA methylation is triggered and regulated. In particular, we have demonstrated that DNA methylation is involved in the regulation of its parasitism-related genes. Further computational analyses indicated that the regulatory machinery for DNA methylation can also be found in the T. spiralis genome. By a logical extension of this point, we speculate that comprehensively addressing the epigenetic machinery of T. spiralis may help to understand epigenetics in invertebrates. Furthermore, considering the implication of epigenetics in metazoan parasitism, using T. spiralis as an epigenetic model organism may further contribute to drug development against metazoan parasites. PMID:24454291

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Discrimination of plant-parasitic nematodes from complex soil communities using ecometagenetics.

    PubMed

    Porazinska, Dorota L; Morgan, Matthew J; Gaspar, John M; Court, Leon N; Hardy, Christopher M; Hodda, Mike

    2014-07-01

    Many plant pathogens are microscopic, cryptic, and difficult to diagnose. The new approach of ecometagenetics, involving ultrasequencing, bioinformatics, and biostatistics, has the potential to improve diagnoses of plant pathogens such as nematodes from the complex mixtures found in many agricultural and biosecurity situations. We tested this approach on a gradient of complexity ranging from a few individuals from a few species of known nematode pathogens in a relatively defined substrate to a complex and poorly known suite of nematode pathogens in a complex forest soil, including its associated biota of unknown protists, fungi, and other microscopic eukaryotes. We added three known but contrasting species (Pratylenchus neglectus, the closely related P. thornei, and Heterodera avenae) to half the set of substrates, leaving the other half without them. We then tested whether all nematode pathogens-known and unknown, indigenous, and experimentally added-were detected consistently present or absent. We always detected the Pratylenchus spp. correctly and with the number of sequence reads proportional to the numbers added. However, a single cyst of H. avenae was only identified approximately half the time it was present. Other plant-parasitic nematodes and nematodes from other trophic groups were detected well but other eukaryotes were detected less consistently. DNA sampling errors or informatic errors or both were involved in misidentification of H. avenae; however, the proportions of each varied in the different bioinformatic pipelines and with different parameters used. To a large extent, false-positive and false-negative errors were complementary: pipelines and parameters with the highest false-positive rates had the lowest false-negative rates and vice versa. Sources of error identified included assumptions in the bioinformatic pipelines, slight differences in primer regions, the number of sequence reads regarded as the minimum threshold for inclusion in analysis

  13. Extending from PARs in Caenorhabditis elegans to homologues in Haemonchus contortus and other parasitic nematodes.

    PubMed

    Nikolaou, S; Gasser, R B

    2007-04-01

    Signal transduction molecules play key roles in the regulation of developmental processes, such as morphogenesis, organogenesis and cell differentiation in all organisms. They are organized into 'pathways' that represent a coordinated network of cell-surface receptors and intracellular molecules, being involved in sensing environmental stimuli and transducing signals to regulate or modulate cellular processes, such as gene expression and cytoskeletal dynamics. A particularly important group of molecules implicated in the regulation of the cytoskeleton for the establishment and maintenance of cell polarity is the PAR proteins (derived from partition defective in asymmetric cell division). The present article reviews salient aspects of PAR proteins involved in the early embryonic development and morphogenesis of the free-living nematode Caenorhabditis elegans and some other organisms, with an emphasis on the molecule PAR-1. Recent advances in the knowledge and understanding of PAR-1 homologues from the economically important parasitic nematode, Haemonchus contortus, of small ruminants is summarized and discussed in the context of exploring avenues for future research in this area for parasitic nematodes. PMID:17107637

  14. Effects of Solarization and Ammonium Amendments on Plant-Parasitic Nematodes

    PubMed Central

    McSorley, R.; McGovern, R. J.

    2000-01-01

    The effects of soil solarization and ammonium bicarbonate or ammonium sulfate against plant-parasitic nematodes on yellow squash (Cucurbita pepo) and on vinca (Catharanthus roseus) were evaluated at two sites. Solarization for 3 weeks in the spring suppressed population levels of Belonolaimus longicaudatus, Criconemella spp., and Dolichodorus heterocephalus throughout the growing season on both crops at both sites. Levels of Meloidogyne incognita were suppressed initially, but population densities increased by the end of the crop in several cases. In one site, numbers of Paratrichodorus minor resurged following solarization to levels that were greater than those present in unsolarized control plots. The effect of solarization was not enhanced by combination with ammonium amendments, but, in one site, application of ammonium bicarbonate or ammonium sulfate resulted in lower numbers of B. longicaudatus than in the unamended control. Additional research and improved efficacy of candidate amendments are required before they can be successfully integrated with solarization for nematode management. Efficacy of solarization against plant-parasitic nematodes was achieved despite a relatively short (3 weeks) solarization period. PMID:19271007

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

    PubMed

    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.

  16. Additional records of metazoan parasites from Caribbean marine mammals, including genetically identified anisakid nematodes.

    PubMed

    Colón-Llavina, Marlene M; Mignucci-Giannoni, Antonio A; Mattiucci, Simonetta; Paoletti, Michela; Nascetti, Giuseppe; Williams, Ernest H

    2009-10-01

    Studies of marine mammal parasites in the Caribbean are scarce. An assessment for marine mammal endo- and ectoparasites from Puerto Rico and the Virgin Islands, but extending to other areas of the Caribbean, was conducted between 1989 and 1994. The present study complements the latter and enhances identification of anisakid nematodes using molecular markers. Parasites were collected from 59 carcasses of stranded cetaceans and manatees from 1994 to 2006, including Globicephala macrorhynchus, Kogia breviceps, Kogia sima, Lagenodelphis hosei, Mesoplodon densirostris, Peponocephala electra, Stenella longirostris, Steno bredanensis, Trichechus manatus. Tursiops truncatus, and Ziphius cavirostris. Sixteen species of endoparasitic helminthes were morphologically identified, including two species of acanthocephalans (Bolbosoma capitatum, Bolbosoma vasculosum), nine species of nematodes (Anisakis sp., Anisakis brevispiculata, Anisakis paggiae, Anisakis simplex, Anisakis typica, Anisakis ziphidarium, Crassicauda anthonyi, Heterocheilus tunicatus, Pseudoterranova ceticola), two species of cestodes (Monorygma grimaldi, Phyllobothrium delphini), and three species of trematodes (Chiorchis groschafti, Pulmonicola cochleotrema, Monoligerum blairi). The nematodes belonging to the genus Anisakis recovered in some stranded animals were genetically identified to species level based on their sequence analysis of mitochondrial DNA (629 bp of mtDNA cox 2). A total of five new host records and six new geographic records are presented. PMID:19582477

  17. Mitochondrial genome haplotype hypervariation within the isopod parasitic nematode Thaumamermis cosgrovei.

    PubMed

    Tang, Sha; Hyman, Bradley C

    2007-06-01

    Characterization of mitochondrial genomes from individual Thaumamermis cosgrovei nematodes, obligate parasites of the isopod Armadillidium vulgare, revealed that numerous mtDNA haplotypes, ranging in size from 19 to 34 kb, are maintained in several spatially separated isopod populations. The magnitude and frequency of conspecific mtDNA size variation is unprecedented among all studied size-polymorphic metazoan mitochondrial genomes. To understand the molecular basis of this hypervariation, complete nucleotide sequences of two T. cosgrovei mtDNA haplotypes were determined. A hypervariable segment, residing between the atp6 and rrnL genes, contributes exclusively to T. cosgrovei mtDNA size variation. Within this region, mtDNA coding genes and putative nonfunctional sequences have accumulated substitutions and are duplicated and rearranged to varying extents. Hypervariation at this level has enabled a first insight into the life history of T. cosgrovei. In five A. vulgare hosts infected with multiple nematodes, four carried nematodes with identical mtDNA haplotypes, suggesting that hosts may become infected by ingesting a recently hatched egg clutch or become parasitized by individuals from the same brood prior to dispersal of siblings within the soil. PMID:17435228

  18. Additional records of metazoan parasites from Caribbean marine mammals, including genetically identified anisakid nematodes.

    PubMed

    Colón-Llavina, Marlene M; Mignucci-Giannoni, Antonio A; Mattiucci, Simonetta; Paoletti, Michela; Nascetti, Giuseppe; Williams, Ernest H

    2009-10-01

    Studies of marine mammal parasites in the Caribbean are scarce. An assessment for marine mammal endo- and ectoparasites from Puerto Rico and the Virgin Islands, but extending to other areas of the Caribbean, was conducted between 1989 and 1994. The present study complements the latter and enhances identification of anisakid nematodes using molecular markers. Parasites were collected from 59 carcasses of stranded cetaceans and manatees from 1994 to 2006, including Globicephala macrorhynchus, Kogia breviceps, Kogia sima, Lagenodelphis hosei, Mesoplodon densirostris, Peponocephala electra, Stenella longirostris, Steno bredanensis, Trichechus manatus. Tursiops truncatus, and Ziphius cavirostris. Sixteen species of endoparasitic helminthes were morphologically identified, including two species of acanthocephalans (Bolbosoma capitatum, Bolbosoma vasculosum), nine species of nematodes (Anisakis sp., Anisakis brevispiculata, Anisakis paggiae, Anisakis simplex, Anisakis typica, Anisakis ziphidarium, Crassicauda anthonyi, Heterocheilus tunicatus, Pseudoterranova ceticola), two species of cestodes (Monorygma grimaldi, Phyllobothrium delphini), and three species of trematodes (Chiorchis groschafti, Pulmonicola cochleotrema, Monoligerum blairi). The nematodes belonging to the genus Anisakis recovered in some stranded animals were genetically identified to species level based on their sequence analysis of mitochondrial DNA (629 bp of mtDNA cox 2). A total of five new host records and six new geographic records are presented.

  19. Distribution of Field Corn Roots and Parasitic Nematodes in Subsoiled and Nonsubsoiled Soil

    PubMed Central

    Rich, J. R.; Hodge, C.; Robertson, W. K.

    1986-01-01

    A field trial was conducted for 2 years in an Arredondo fine sand containing a tillage pan at 15-20 cm deep to determine the influence of subsoiling on the distribution of corn roots and plant-parasitic nematodes. Soil samples were taken at various depths and row positions at 30, 60, and 90 days after planting in field corn subsoiled under the row with two chisels and in non-subsoiled corn. At 30 and 60 days, in-row nematode population densities to 60 cm deep were not affected by subsoiling compared with population densities in nonsubsoiled plots. After 90 days, subsoiling had not affected total root length or root weight at the 20 depth-row position sampling combinations, but population densities of Meloidogyne incognita and Criconemella spp. had increased in subsoiled corn. Numbers of Pratylenchus zeae were not affected. Subsoiling generally resulted in a change in distribution of corn roots and nematodes in the soil profile but caused little total increase in either roots or numbers of nematodes. Corn yield was increased by subsoiling. PMID:19294167

  20. Nematodes (Rhabditida: Steinernematidae and Heterorhabditidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematodes are roundworms in the phylum Nematoda. Although most are free-living, some nematodes are parasites of plants, humans, or livestock. Entomopathogenic nematodes in the families Steinernematidae & Heterorhabditidae only parasitize insects. These nematodes are used as environmentally friend...

  1. Strongyloides stercoralis: a model for translational research on parasitic nematode biology.

    PubMed

    Lok, James B

    2007-01-01

    Because of their free-living life cycle alternatives, Strongyloides and related nematode parasites may represent the best models for translating C. elegans science to the study of nematode parasitism. S. stercoralis, a significant pathogen of humans, can be maintained in laboratory dogs and gerbils. Biosafety precautions necessary for work with S. stercoralis, though unfamiliar to many C. elegans researchers, are straightforward and easily accomplished. Although specialized methods are necessary for large-scale culture of the free-living stages of S. stercoralis, small-scale cultures for experimental purposes may be undertaken using minor modifications of standard C. elegans methods. Similarly, the morphological similarities between C. elegans and the free-living stages of S. stercoralis allow investigational methods such as laser cell ablation and DNA transformation by gonadal microinjection to be easily adapted from C. elegans to S. stercoralis. Comparative studies employing these methods have yielded new insights into the neuronal control of the infective process in parasites and its similarity to regulation of dauer development in C. elegans. Furthermore, we have developed a practical method for transient transformation of S. stercoralis with vector constructs having various tissue- and cell-specific expression patterns and have assembled these into a modular vector kit for distribution to the community. PMID:18050500

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

    PubMed Central

    Wondafrash, Mesfin; Van Dam, Nicole M.; Tytgat, Tom O. G.

    2013-01-01

    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 (PPNs) 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 defense, interference with the translocation and dynamics of locally induced secondary metabolites, and reallocation of plant nutritional reserves. During evolution, PPNs as well as herbivorous insects have acquired effectors that modify plant defense 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 development of sustainable pest

  3. No evidence for behavioural adaptations to nematode parasitism by the fly Drosophila putrida.

    PubMed

    Debban, C L; Dyer, K A

    2013-08-01

    Behavioural adaptations of hosts to their parasites form an important component of the evolutionary dynamics of host-parasite interactions. As mushroom-feeding Drosophila can tolerate deadly mycotoxins, but their Howardula nematode parasites cannot, we asked how consuming the potent mycotoxin α-amanitin has affected this host-parasite interaction. We used the fly D. putrida and its parasite H. aoronymphium, which is both highly virulent and at high prevalence in some populations, and investigated whether adult flies utilize food with toxin to prevent infection in the next generation or consume the toxin to reduce the virulence of an already established infection. First, we found that uninfected females did not prefer to eat or lay their eggs on toxic food, indicating that selection has not acted on the flies to alter their behaviour towards α-amanitin to prevent their offspring from becoming infected by Howardula. However, we cannot rule out that flies use an alternate cue that is associated with toxin presence in the wild. Second, we found that infected females did not prefer to eat food with α-amanitin and that consuming α-amanitin did not cure or reduce the virulence of the parasite in adults that were already infected. In sum, our results indicate there are no direct effects of eating α-amanitin on this host-parasite interaction, and we suggest that toxin tolerance is more likely maintained by selection due to competition for resources than as a mechanism to avoid parasite infection or to reduce the virulence of infection. PMID:23663194

  4. No evidence for behavioural adaptations to nematode parasitism by the fly Drosophila putrida.

    PubMed

    Debban, C L; Dyer, K A

    2013-08-01

    Behavioural adaptations of hosts to their parasites form an important component of the evolutionary dynamics of host-parasite interactions. As mushroom-feeding Drosophila can tolerate deadly mycotoxins, but their Howardula nematode parasites cannot, we asked how consuming the potent mycotoxin α-amanitin has affected this host-parasite interaction. We used the fly D. putrida and its parasite H. aoronymphium, which is both highly virulent and at high prevalence in some populations, and investigated whether adult flies utilize food with toxin to prevent infection in the next generation or consume the toxin to reduce the virulence of an already established infection. First, we found that uninfected females did not prefer to eat or lay their eggs on toxic food, indicating that selection has not acted on the flies to alter their behaviour towards α-amanitin to prevent their offspring from becoming infected by Howardula. However, we cannot rule out that flies use an alternate cue that is associated with toxin presence in the wild. Second, we found that infected females did not prefer to eat food with α-amanitin and that consuming α-amanitin did not cure or reduce the virulence of the parasite in adults that were already infected. In sum, our results indicate there are no direct effects of eating α-amanitin on this host-parasite interaction, and we suggest that toxin tolerance is more likely maintained by selection due to competition for resources than as a mechanism to avoid parasite infection or to reduce the virulence of infection.

  5. In planta processing and glycosylation of a nematode CLE effector and its interaction with a CLV2-like receptor to promote parasitism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ESR (CLE)-like proteins have been identified in several cyst nematodes including the potato cyst nematode (PCN); however, th...

  6. Insights into the structure-function relationship of Brugia malayi thymidylate kinase (BmTMK).

    PubMed

    Doharey, Pawan Kumar; Singh, Sudhir Kumar; Verma, Pravesh; Verma, Anita; Rathaur, Sushma; Saxena, Jitendra Kumar

    2016-07-01

    Lymphatic filariasis is a debilitating disease caused by lymph dwelling nematodal parasites like Wuchereria bancrofti, Brugia malayi and Brugia timori. Thymidylate kinase of B. malayi is a key enzyme in the de novo and salvage pathways for thymidine 5'-triphosphate (dTTP) synthesis. Therefore, B. malayi thymidylate kinase (BmTMK) is an essential enzyme for DNA biosynthesis and an important drug target to rein in filariasis. In the present study, the structural and functional changes associated with recombinant BmTMK, in the presence of protein denaturant GdnHCl, urea and pH were studied. GdnHCl and urea induced unfolding of BmTMK is non-cooperative and influence the functional property of the enzyme much lower than their Cm values. The study delineate that BmTMK is more prone to ionic perturbation. The dimeric assembly of BmTMK is an absolute requirement for enzymatic acitivity and any subtle change in dimeric conformation due to denaturation leads to loss of enzymatic activity. The pH induced changes on structure and activity suggests that selective modification of active site microenvironment pertains to difference in activity profile. This study also envisages that chemical moieties which acts by modulating oligomeric assembly, could be used for better designing of inhibitors against BmTMK enzyme. PMID:27044348

  7. Identification of a Bacteria-Like Ferrochelatase in Strongyloides venezuelensis, an Animal Parasitic Nematode

    PubMed Central

    Nagayasu, Eiji; Ishikawa, Sohta A.; Taketani, Shigeru; Chakraborty, Gunimala; Yoshida, Ayako; Inagaki, Yuji; Maruyama, Haruhiko

    2013-01-01

    Heme is an essential molecule for vast majority of organisms serving as a prosthetic group for various hemoproteins. Although most organisms synthesize heme from 5-aminolevulinic acid through a conserved heme biosynthetic pathway composed of seven consecutive enzymatic reactions, nematodes are known to be natural heme auxotrophs. The completely sequenced Caenorhabditis elegans genome, for example, lacks all seven genes for heme biosynthesis. However, genome/transcriptome sequencing of Strongyloides venezuelensis, an important model nematode species for studying human strongyloidiasis, indicated the presence of a gene for ferrochelatase (FeCH), which catalyzes the terminal step of heme biosynthesis, whereas the other six heme biosynthesis genes are apparently missing. Phylogenetic analyses indicated that nematode FeCH genes, including that of S. venezuelensis (SvFeCH) have a fundamentally different evolutionally origin from the FeCH genes of non-nematode metazoa. Although all non-nematode metazoan FeCH genes appear to be inherited vertically from an ancestral opisthokont, nematode FeCH may have been acquired from an alpha-proteobacterium, horizontally. The identified SvFeCH sequence was found to function as FeCH as expected based on both in vitro chelatase assays using recombinant SvFeCH and in vivo complementation experiments using an FeCH-deficient strain of Escherichia coli. Messenger RNA expression levels during the S. venezuelensis lifecycle were examined by real-time RT-PCR. SvFeCH mRNA was expressed at all the stages examined with a marked reduction at the infective third-stage larvae. Our study demonstrates the presence of a bacteria-like FeCH gene in the S. venezuelensis genome. It appeared that S. venezuelensis and some other animal parasitic nematodes reacquired the once-lost FeCH gene. Although the underlying evolutionary pressures that necessitated this reacquisition remain to be investigated, it is interesting that the presence of FeCH genes in the

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

    PubMed Central

    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. PMID:26332126

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

    PubMed

    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.

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

    PubMed

    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. PMID:26332126

  11. Nematodes parasitic in fishes of cenotes (= sinkholes) of the Peninsula of Yucatan, Mexico. Part 2. Larvae.

    PubMed

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

    1995-01-01

    This paper comprises a systematic survey of larval nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southern Mexico, in 1993-1994. Larvae of the following nine species were recorded: Physocephalus sexalatus, Acuariidae gen. sp., Spiroxys sp., Falcaustra sp., Hysterothylacium cenotae, Contracaecum sp. Type 1, Contracaecum sp. Type 2, Goezia sp., and Eustrongylides sp. Larvae of P. sexalatus are recorded from fishes (Rhamdia guatemalensis) for the first time. The larvae are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Adults of these larvae are parasitic in piscivorous fishes, reptiles, birds and mammals (definitive hosts). Fishes harbouring the larvae of these parasites serve as paratenic hosts, being mostly an important source of infection for the definitive hosts. PMID:8774773

  12. Nematodes parasitic in fishes of cenotes (= sinkholes) of the Peninsula of Yucatan, Mexico. Part 2. Larvae.

    PubMed

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

    1995-01-01

    This paper comprises a systematic survey of larval nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southern Mexico, in 1993-1994. Larvae of the following nine species were recorded: Physocephalus sexalatus, Acuariidae gen. sp., Spiroxys sp., Falcaustra sp., Hysterothylacium cenotae, Contracaecum sp. Type 1, Contracaecum sp. Type 2, Goezia sp., and Eustrongylides sp. Larvae of P. sexalatus are recorded from fishes (Rhamdia guatemalensis) for the first time. The larvae are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Adults of these larvae are parasitic in piscivorous fishes, reptiles, birds and mammals (definitive hosts). Fishes harbouring the larvae of these parasites serve as paratenic hosts, being mostly an important source of infection for the definitive hosts.

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

    PubMed

    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) PMID:7898896

  14. The cytochrome P450 family in the parasitic nematode Haemonchus contortus

    PubMed Central

    Laing, Roz; Bartley, David J.; Morrison, Alison A.; Rezansoff, Andrew; Martinelli, Axel; Laing, Steven T.; Gilleard, John S.

    2015-01-01

    Haemonchus contortus, a highly pathogenic and economically important parasitic nematode of sheep, is particularly adept at developing resistance to the anthelmintic drugs used in its treatment and control. The basis of anthelmintic resistance is poorly understood for many commonly used drugs with most research being focused on mechanisms involving drug targets or drug efflux. Altered or increased drug metabolism is a possible mechanism that has yet to receive much attention despite the clear role of xenobiotic metabolism in pesticide resistance in insects. The cytochrome P450s (CYPs) are a large family of drug-metabolising enzymes present in almost all living organisms, but for many years thought to be absent from parasitic nematodes. In this paper, we describe the CYP sequences encoded in the H. contortus genome and compare their expression in different parasite life-stages, sexes and tissues. We developed a novel real-time PCR approach based on partially assembled CYP sequences “tags” and confirmed findings in the subsequent draft genome with RNA-seq. Constitutive expression was highest in larval stages for the majority of CYPs, although higher expression was detected in the adult male or female for a small subset of genes. Many CYPs were expressed in the worm intestine. A number of H. contortus genes share high identity with Caenorhabditis elegans CYPs and the similarity in their expression profiles supports their classification as putative orthologues. Notably, H. contortus appears to lack the dramatic CYP subfamily expansions seen in C. elegans and other species, which are typical of CYPs with exogenous roles. However, a small group of H. contortus genes cluster with the C. elegans CYP34 and CYP35 subfamilies and may represent candidate xenobiotic metabolising genes in the parasite. PMID:25558056

  15. Potential of microwaves to control plant-parasitic nematodes in soil.

    PubMed

    Rahi, Gurcharan S; Rich, Jimmy R

    2008-01-01

    Microwave radiation of 2450 MHz frequency was used to irradiate sandy loam soil placed in 12 cm high and 10 cm dia columns as a function of exposure times of 30, 45, 60, and 120 s. This was done to evaluate the effect of radiation on the highest soil temperature attained and subsequent temperature patterns in relation to time. Soil columns were packed to a field bulk density of approximately 1.4 g/cm3, and treatments consisted of moist soil, dry soil, and layers of moist and dry soil of varying thicknesses. Moisture contents of moist and dry soil were 10% and 2%, respectively, on a dry mass basis. An exposure time of 45 seconds was the most efficient in yielding soil temperatures high enough to kill plant-parasitic nematodes. Irradiation of soil infested with Rotylenchulus reniform nematodes for 45 seconds resulted in a 99% extermination of the organisms in all treatments. However, radiation proved to be most effective in nematode control with 6.0 cm dry soil placed over 6.0 cm moist soil.

  16. Effect of moisture on efficiency of microwaves to control plant--parasitic nematodes in soil.

    PubMed

    Rahi, Gurcharan S; Rich, Jimmy R

    2011-01-01

    Laboratory studies were conducted to evaluate effect of microwave irradiation of sandy loam soil on thermal energy absorption and control of plant-parasitic nematodes when air dry soil layers were placed on top of less moist, moist, and wet soil layers. The soil was packed in 12 cm high and 10 cm dia columns to a bulk density of 1.4 g/cm3. Moisture contents of air dry, less moist, moist, and wet soils were 0.75, 4.50, 6.00, and 10.30%, respectively, on dry mass basis. The top air dry soil was 4.0 cm thick and the bottom layer was 8.0 cm thick. Temperature measurements and thermal radiation absorption data were monitored in both soil layers and showed that the use of a top dry soil both increased depth of penetration of microwave radiation and it provided insulation for better absorption of thermal energy in the lower layer of soil. An exposure of 65 seconds resulted in soil temperatures high enough to cause significant decrease in nematode population in soil infested with Rotylenchulus reniformis nematodes. No such effect was observed in combination where dry soil layer was placed over dry soil at the bottom. These results are helpful in sterilizing soil used for greenhouses and nurseries.

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

    PubMed

    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.

  18. A simple and efficient protocol for the treatment of zebrafish colonies infected with parasitic nematodes.

    PubMed

    Maley, David; Laird, Angela S; Rinkwitz, Silke; Becker, Thomas S

    2013-09-01

    Abstract Our zebrafish colony experienced a period of increased mortality rate of 6.5 times more deaths per month in a colony of over 13,000 zebrafish (Danio rerio), which developed over 3 months. We observed that before death, affected fish appeared emaciated, often with an abdominal bulge. We performed dissection on 18 fish that had this appearance and found in 15 that their gut was infected with a nematode that closely resembled Pseudocapillaria tomentosa. We devised a treatment protocol for this nematode infection, which involved addition of fenbendazole, a drug used to treat nematode infections in cattle and sheep, to the fish feed. Fenbendazole produced no severe side effects in the fish and several treatments have effectively eradicated the parasite from our colony. The mortality rate of our fish has decreased to a value of 0.7%/month (p<0.001, equal to that before the infection). We propose this protocol as an inexpensive alternative to having to rederive an entire colony from bleached eggs, and as a prophylactic measure used in quarantine facilities on a regular basis.

  19. Potential of microwaves to control plant-parasitic nematodes in soil.

    PubMed

    Rahi, Gurcharan S; Rich, Jimmy R

    2008-01-01

    Microwave radiation of 2450 MHz frequency was used to irradiate sandy loam soil placed in 12 cm high and 10 cm dia columns as a function of exposure times of 30, 45, 60, and 120 s. This was done to evaluate the effect of radiation on the highest soil temperature attained and subsequent temperature patterns in relation to time. Soil columns were packed to a field bulk density of approximately 1.4 g/cm3, and treatments consisted of moist soil, dry soil, and layers of moist and dry soil of varying thicknesses. Moisture contents of moist and dry soil were 10% and 2%, respectively, on a dry mass basis. An exposure time of 45 seconds was the most efficient in yielding soil temperatures high enough to kill plant-parasitic nematodes. Irradiation of soil infested with Rotylenchulus reniform nematodes for 45 seconds resulted in a 99% extermination of the organisms in all treatments. However, radiation proved to be most effective in nematode control with 6.0 cm dry soil placed over 6.0 cm moist soil. PMID:19227078

  20. RNAseq Analysis of the Parasitic Nematode Strongyloides stercoralis Reveals Divergent Regulation of Canonical Dauer Pathways

    PubMed Central

    Stoltzfus, Jonathan D.; Minot, Samuel; Berriman, Matthew; Nolan, Thomas J.; Lok, James B.

    2012-01-01

    The infectious form of many parasitic nematodes, which afflict over one billion people globally, is a developmentally arrested third-stage larva (L3i). The parasitic nematode Strongyloides stercoralis differs from other nematode species that infect humans, in that its life cycle includes both parasitic and free-living forms, which can be leveraged to investigate the mechanisms of L3i arrest and activation. The free-living nematode Caenorhabditis elegans has a similar developmentally arrested larval form, the dauer, whose formation is controlled by four pathways: cyclic GMP (cGMP) signaling, insulin/IGF-1-like signaling (IIS), transforming growth factor β (TGFβ) signaling, and biosynthesis of dafachronic acid (DA) ligands that regulate a nuclear hormone receptor. We hypothesized that homologous pathways are present in S. stercoralis, have similar developmental regulation, and are involved in L3i arrest and activation. To test this, we undertook a deep-sequencing study of the polyadenylated transcriptome, generating over 2.3 billion paired-end reads from seven developmental stages. We constructed developmental expression profiles for S. stercoralis homologs of C. elegans dauer genes identified by BLAST searches of the S. stercoralis genome as well as de novo assembled transcripts. Intriguingly, genes encoding cGMP pathway components were coordinately up-regulated in L3i. In comparison to C. elegans, S. stercoralis has a paucity of genes encoding IIS ligands, several of which have abundance profiles suggesting involvement in L3i development. We also identified seven S. stercoralis genes encoding homologs of the single C. elegans dauer regulatory TGFβ ligand, three of which are only expressed in L3i. Putative DA biosynthetic genes did not appear to be coordinately regulated in L3i development. Our data suggest that while dauer pathway genes are present in S. stercoralis and may play a role in L3i development, there are significant differences between the two species

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

    PubMed Central

    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

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

    PubMed

    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. Exploring the Gastrointestinal “Nemabiome”: Deep Amplicon Sequencing to Quantify the Species Composition of Parasitic Nematode Communities

    PubMed Central

    Avramenko, Russell W.; Redman, Elizabeth M.; Lewis, Roy; Yazwinski, Thomas A.; Wasmuth, James D.; Gilleard, John S.

    2015-01-01

    Parasitic helminth infections have a considerable impact on global human health as well as animal welfare and production. Although co-infection with multiple parasite species within a host is common, there is a dearth of tools with which to study the composition of these complex parasite communities. Helminth species vary in their pathogenicity, epidemiology and drug sensitivity and the interactions that occur between co-infecting species and their hosts are poorly understood. We describe the first application of deep amplicon sequencing to study parasitic nematode communities as well as introduce the concept of the gastro-intestinal “nemabiome”. The approach is analogous to 16S rDNA deep sequencing used to explore microbial communities, but utilizes the nematode ITS-2 rDNA locus instead. Gastro-intestinal parasites of cattle were used to develop the concept, as this host has many well-defined gastro-intestinal nematode species that commonly occur as complex co-infections. Further, the availability of pure mono-parasite populations from experimentally infected cattle allowed us to prepare mock parasite communities to determine, and correct for, species representation biases in the sequence data. We demonstrate that, once these biases have been corrected, accurate relative quantitation of gastro-intestinal parasitic nematode communities in cattle fecal samples can be achieved. We have validated the accuracy of the method applied to field-samples by comparing the results of detailed morphological examination of L3 larvae populations with those of the sequencing assay. The results illustrate the insights that can be gained into the species composition of parasite communities, using grazing cattle in the mid-west USA as an example. However, both the technical approach and the concept of the ‘nemabiome’ have a wide range of potential applications in human and veterinary medicine. These include investigations of host-parasite and parasite-parasite interactions

  4. Syntaxin 31 functions in Glycine max resistance to the plant parasitic nematode Heterodera glycines.

    PubMed

    Pant, Shankar R; Matsye, Prachi D; McNeece, Brant T; Sharma, Keshav; Krishnavajhala, Aparna; Lawrence, Gary W; Klink, Vincent P

    2014-05-01

    A Glycine max syntaxin 31 homolog (Gm-SYP38) was identified as being expressed in nematode-induced feeding structures known as syncytia undergoing an incompatible interaction with the plant parasitic nematode Heterodera glycines. The observed Gm-SYP38 expression was consistent with prior gene expression analyses that identified the alpha soluble NSF attachment protein (Gm-α-SNAP) resistance gene because homologs of these genes physically interact and function together in other genetic systems. Syntaxin 31 is a protein that resides on the cis face of the Golgi apparatus and binds α-SNAP-like proteins, but has no known role in resistance. Experiments presented here show Gm-α-SNAP overexpression induces Gm-SYP38 transcription. Overexpression of Gm-SYP38 rescues G. max [Williams 82/PI 518671], genetically rhg1 (-/-), by suppressing H. glycines parasitism. In contrast, Gm-SYP38 RNAi in the rhg1 (+/+) genotype G. max [Peking/PI 548402] increases susceptibility. Gm-α-SNAP and Gm-SYP38 overexpression induce the transcriptional activity of the cytoplasmic receptor-like kinase BOTRYTIS INDUCED KINASE 1 (Gm-BIK1-6) which is a family of defense proteins known to anchor to membranes through a 5' MGXXXS/T(R) N-myristoylation sequence. Gm-BIK1-6 had been identified previously by RNA-seq experiments as expressed in syncytia undergoing an incompatible reaction. Gm-BIK1-6 overexpression rescues the resistant phenotype. In contrast, Gm-BIK1-6 RNAi increases parasitism. The analysis demonstrates a role for syntaxin 31-like genes in resistance that until now was not known.

  5. Rapid method for recovery of strongylid third stage larvae of parasitic nematodes from small soil samples.

    PubMed

    Knapp-Lawitzke, Friederike; von Samson-Himmelstjerna, Georg; Demeler, Janina

    2014-07-01

    Livestock with access to pasture is generally exposed to infections with parasitic nematode species by uptake of infective third stage larvae (L3) with the grass. L3 can survive on pasture and particularly also in the soil up to several months and sometimes even longer, depending on temperature and humidity. As indicators for health and productivity of grazing animals it is important to determine the intensity and species spectrum of parasitic nematode larvae by analysing grass as well as soil samples. A rapid method for the recovery of L3 using a centrifugal-flotation technique from soil samples of 50-500 g was developed. The method takes advantage of the low specific weight of larvae to separate them from equal sized soil and debris particles by centrifuging them in a saturated sugar solution. A stack of differently sized sieves is used to achieve elimination of larger particles, dust and sugar from the sample to enable easy counting of larvae. Independent of the number of larvae used for inoculation of the samples a mean recovery of 75.3% was obtained. The recovery rates obtained ranged between 60.8% and 88.0% which demonstrates a considerably lower variability compared to earlier approaches and therefore a more precise estimation of the actual numbers of parasite larvae in soil is achieved. Further advantages over already developed methods are the use of easy, affordable and eco-friendly materials, the simplicity of the procedure and a faster processing time with the possibility to examine up to 20 samples per day.

  6. Monoaminergic signaling as a target for anthelmintic drug discovery: receptor conservation among the free-living and parasitic nematodes.

    PubMed

    Komuniecki, Richard; Law, Wen Jing; Jex, Aaron; Geldhof, Peter; Gray, John; Bamber, Bruce; Gasser, Robin B

    2012-05-01

    This review is designed to summarize the information on monoamine-dependent paralysis as a target for anthelmintic development, examine the conservation of monoamine receptors in the genomes of both free-living and parasitic nematodes, and highlight the utility of the Caenorhabditis elegans model system for dissecting the monoaminergic modulation of locomotory decision-making. PMID:22343182

  7. Monoaminergic signaling as a target for anthelmintic drug discovery: receptor conservation among the free-living and parasitic nematodes.

    PubMed

    Komuniecki, Richard; Law, Wen Jing; Jex, Aaron; Geldhof, Peter; Gray, John; Bamber, Bruce; Gasser, Robin B

    2012-05-01

    This review is designed to summarize the information on monoamine-dependent paralysis as a target for anthelmintic development, examine the conservation of monoamine receptors in the genomes of both free-living and parasitic nematodes, and highlight the utility of the Caenorhabditis elegans model system for dissecting the monoaminergic modulation of locomotory decision-making.

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

    PubMed Central

    2014-01-01

    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. PMID:24580726

  9. Invasion, establishment, and range expansion of two parasitic nematodes in the Canadian Arctic.

    PubMed

    Kutz, Susan J; Checkley, Sylvia; Verocai, Guilherme G; Dumond, Mathieu; Hoberg, Eric P; Peacock, Rod; Wu, Jessica P; Orsel, Karin; Seegers, Karin; Warren, Amy L; Abrams, Arthur

    2013-11-01

    Climate warming is occurring at an unprecedented rate in the Arctic and is having profound effects on host-parasite interactions, including range expansion. Recently, two species of protostrongylid nematodes have emerged for the first time in muskoxen and caribou on Victoria Island in the western Canadian Arctic Archipelago. Umingmakstrongylus pallikuukensis, the muskox lungworm, was detected for the first time in 2008 in muskoxen at a community hunt on the southwest corner of the island and by 2012, it was found several hundred kilometers east in commercially harvested muskoxen near the town of Ikaluktutiak. In 2010, Varestrongylus sp., a recently discovered lungworm of caribou and muskoxen was found in muskoxen near Ikaluktutiak and has been found annually in this area since then. Whereas invasion of the island by U. pallikuukensis appears to have been mediated by stochastic movement of muskoxen from the mainland to the southwest corner of the island, Varestrongylus has likely been introduced at several times and locations by the seasonal migration of caribou between the island and the mainland. A newly permissive climate, now suitable for completion of the parasite life cycles in a single summer, likely facilitated the initial establishment and now drives range expansion for both parasites.

  10. Morphology and taxonomic status of two little-known nematode species parasitizing North American fishes.

    PubMed

    Moravec, František; Levron, Céline; de Buron, Isaure

    2011-04-01

    Examination of some freshwater and brackishwater (estuarine) fishes in South Carolina in October 2009 yielded, in addition to other parasites, 2 little-known nematode species identified as Dichelyne fastigatus Chandler, 1935 (Cucullanidae), from the red drum, Sciaenops ocellatus (Linnaeus), from an estuary, and Rhabdochona ovifilamenta Weller, 1938 (Rhabdochonidae), from the shorthead redhorse, Moxostoma macrolepidotum (Lesueur), from Lake Moultrie. Light and scanning electron microscopy (the latter used for the first time for these species) made it possible to describe several important, but previously unreported, taxonomic features in D. fastigatus, such as the location of the excretory pore and deirids, the shape of deirids and a gubernaculum, the shape and size of eggs, the presence of precloacal ventral oblique muscle bands, and 11 pairs of caudal papillae and a pair of phasmids. It distinctly differs from the most similar Dichelyne cotylophora (Ward and Magath, 1917), a parasite of North American freshwater percids, in the number and arrangement of postanal papillae and by a markedly elevated cloacal region. Records of Dichelyne lintoni Barreto, 1922, from S. ocellatus probably concern D. fastigatus. Examination of R. ovifilamenta revealed a high degree of morphologic and biometric variability in this species. Based on our analysis, Rhabdochona laurentiana Lyster, 1940 , Rhabdochona milleri Choquette, 1951, and Rhabdochona catostomi Kayton, Kritsky, and Tobias, 1979, are synonymized with R. ovifilamenta Weller, 1938, typically a parasite of North American catostomids. PMID:21506872

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

    PubMed Central

    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.

    2016-01-01

    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. PMID:27084478

  12. Invasion, establishment, and range expansion of two parasitic nematodes in the Canadian Arctic.

    PubMed

    Kutz, Susan J; Checkley, Sylvia; Verocai, Guilherme G; Dumond, Mathieu; Hoberg, Eric P; Peacock, Rod; Wu, Jessica P; Orsel, Karin; Seegers, Karin; Warren, Amy L; Abrams, Arthur

    2013-11-01

    Climate warming is occurring at an unprecedented rate in the Arctic and is having profound effects on host-parasite interactions, including range expansion. Recently, two species of protostrongylid nematodes have emerged for the first time in muskoxen and caribou on Victoria Island in the western Canadian Arctic Archipelago. Umingmakstrongylus pallikuukensis, the muskox lungworm, was detected for the first time in 2008 in muskoxen at a community hunt on the southwest corner of the island and by 2012, it was found several hundred kilometers east in commercially harvested muskoxen near the town of Ikaluktutiak. In 2010, Varestrongylus sp., a recently discovered lungworm of caribou and muskoxen was found in muskoxen near Ikaluktutiak and has been found annually in this area since then. Whereas invasion of the island by U. pallikuukensis appears to have been mediated by stochastic movement of muskoxen from the mainland to the southwest corner of the island, Varestrongylus has likely been introduced at several times and locations by the seasonal migration of caribou between the island and the mainland. A newly permissive climate, now suitable for completion of the parasite life cycles in a single summer, likely facilitated the initial establishment and now drives range expansion for both parasites. PMID:23828740

  13. A ubiquitin carboxyl extension protein secreted from a plant-parasitic nematode Globodera rostochiensis is cleaved in planta to promote plant parasitism.

    PubMed

    Chronis, Demosthenis; Chen, Shiyan; Lu, Shunwen; Hewezi, Tarek; Carpenter, Sara C D; Loria, Rosemary; Baum, Thomas J; Wang, Xiaohong

    2013-04-01

    Nematode effector proteins originating from esophageal gland cells play central roles in suppressing plant defenses and in formation of the plant feeding cells that are required for growth and development of cyst nematodes. A gene (GrUBCEP12) encoding a unique ubiquitin carboxyl extension protein (UBCEP) that consists of a signal peptide for secretion, a mono-ubiquitin domain, and a 12 amino acid carboxyl extension protein (CEP12) domain was cloned from the potato cyst nematode Globodera rostochiensis. This GrUBCEP12 gene was expressed exclusively within the nematode's dorsal esophageal gland cell, and was up-regulated in the parasitic second-stage juvenile, correlating with the time when feeding cell formation is initiated. We showed that specific GrUBCEP12 knockdown via RNA interference reduced nematode parasitic success, and that over-expression of the secreted Gr(Δ) (SP) UBCEP12 protein in potato resulted in increased nematode susceptibility, providing direct evidence that this secreted effector is involved in plant parasitism. Using transient expression assays in Nicotiana benthamiana, we found that Gr(Δ) (SP) UBCEP12 is processed into free ubiquitin and a CEP12 peptide (GrCEP12) in planta, and that GrCEP12 suppresses resistance gene-mediated cell death. A target search showed that expression of RPN2a, a gene encoding a subunit of the 26S proteasome, was dramatically suppressed in Gr(Δ) (SP) UBCEP12 but not GrCEP12 over-expression plants when compared with control plants. Together, these results suggest that, when delivered into host plant cells, Gr(Δ) (SP) UBCEP12 becomes two functional units, one acting to suppress plant immunity and the other potentially affecting the host 26S proteasome, to promote feeding cell formation.

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

    PubMed Central

    2010-01-01

    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. PMID:20653938

  15. Plant-Parasitic Nematodes Associated with Grapevines, Vitis vinifera, in Oregon Vineyards

    PubMed Central

    Pinkerton, J. N.; Forge, T. A.; Ivors, K. L.; Ingham, R. E.

    1999-01-01

    A survey of vineyards in western Oregon was conducted in 1994 and 1995 to determine the association of plant-parasitic nematodes with vine health. Seventy vineyards in four regions of western Oregon (16 to 21 vineyards per region) were sampled. The regions were the northern, middle, and southern Willamette Valley, and southern Oregon. Vineyards were selected and partitioned into blocks by variety, age of planting, crop history, and soil characteristics. Mesocriconema xenoplax, Xiphinema americanum, Pratylenchus spp., and Paratylenchus spp. were recovered from more than 85% of the vineyards; only 10% of vineyards had detectable populations of Meloidogyne hapla. Mesocriconema xenoplax and X. americanum were found in 20% and 8% of vineyard blocks, respectively, at population densities reported to cause moderate yield loss in California. Mesocriconema xenoplax was found at greatest population densities in vineyards older than 10 years and on former Prunus orchard sites in the northern Willamette Valley. Populations of Mesocriconema xenoplax and X. americanum were associated with both healthy and stunted vines. The long-term impact of M. xenoplax, X. americanum, and other nematodes on Oregon vineyard production has not yet been determined. PMID:19270927

  16. Genomics of Loa loa, a Wolbachia-free filarial parasite of humans.

    PubMed

    Desjardins, Christopher A; Cerqueira, Gustavo C; Goldberg, Jonathan M; Dunning Hotopp, Julie C; Haas, Brian J; Zucker, Jeremy; Ribeiro, José M C; Saif, Sakina; Levin, Joshua Z; Fan, Lin; Zeng, Qiandong; Russ, Carsten; Wortman, Jennifer R; Fink, Doran L; Birren, Bruce W; Nutman, Thomas B

    2013-05-01

    Loa loa, the African eyeworm, is a major filarial pathogen of humans. Unlike most filariae, L. loa does not contain the obligate intracellular Wolbachia endosymbiont. We describe the 91.4-Mb genome of L. loa and that of the related filarial parasite Wuchereria bancrofti and predict 14,907 L. loa genes on the basis of microfilarial RNA sequencing. By comparing these genomes to that of another filarial parasite, Brugia malayi, and to those of several other nematodes, we demonstrate synteny among filariae but not with nonparasitic nematodes. The L. loa genome encodes many immunologically relevant genes, as well as protein kinases targeted by drugs currently approved for use in humans. Despite lacking Wolbachia, L. loa shows no new metabolic synthesis or transport capabilities compared to other filariae. These results suggest that the role of Wolbachia in filarial biology is more subtle than previously thought and reveal marked differences between parasitic and nonparasitic nematodes. PMID:23525074

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

    PubMed

    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.

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

    PubMed

    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.

  19. Incidence and Pathogenicity of Plant-Parasitic Nematodes Associated with Blueberry (Vaccinium spp.) Replant Disease in Georgia and North Carolina

    PubMed Central

    Jagdale, Ganpati B.; Holladay, Ted; Brannen, P. M.; Cline, W. O.; Agudelo, P.; Nyczepir, A. P.; Noe, J. P.

    2013-01-01

    Blueberry replant disease (BRD) is an emerging threat to continued blueberry (Vaccinium spp.) production in Georgia and North Carolina. Since high populations of ring nematode Mesocriconema ornatum were found to be associated with commercially grown blueberries in Georgia, we hypothesized that M. ornatum may be responsible for predisposing blueberry to BRD. We therefore tested the pathogenicity of M. ornatum on 10-wk-old Rabbiteye blueberries (Vaccinium virgatum) by inoculating with initial populations (Pi) of 0 (water control), 10, 100, 1,000. and 10,000 mixed stages of M. ornatum/pot under both greenhouse (25 ± 2°C) and field microplot conditions. Nematode soil population densities and reproduction rates were assessed 75, 150, 225, and 255, and 75, 150, 225, and 375 d after inoculation (DAI) in both the greenhouse and field experiments, respectively. Plant growth parameters were recorded in the greenhouse and field microplot experiments at 255 and 375 DAI, respectively. The highest M. ornatum population density occurred with the highest Pi level, at 75 and 150 DAI under both greenhouse (P < 0.01) and field (P < 0.01) conditions. However, M. ornatum rate of reproduction increased significantly in pots receiving the lowest Pi level of 10 nematodes/plant compared with the pots receiving Pi levels of 100, 1,000, and 10,000 nematodes 75 DAI. Plant-parasitic nematode populations were determined in commercial blueberry replant sites in Georgia and North Carolina during the 2010 growing season. Mesocriconema ornatum and Dolichodorus spp. were the predominant plant-parasitic nematodes in Georgia and North Carolina, respectively, with M. ornatum occurring in nearly half the blueberry fields sampled in Georgia. Other nematode genera detected in both states included Tylenchorhynchus spp., Hoplolaimus spp., Hemicycliophora spp., and Xiphinema spp. Paratrichodorus spp. was also found only in Georgia. In Georgia, our results indicate that blueberry is a host for M. ornatum

  20. Pochonia chlamydosporia: Advances and Challenges to Improve Its Performance as a Biological Control Agent of Sedentary Endo-parasitic Nematodes

    PubMed Central

    Manzanilla-López, Rosa H.; Esteves, Ivania; Finetti-Sialer, Mariella M.; Hirsch, Penny R.; Ward, Elaine; Devonshire, Jean; Hidalgo-Díaz, Leopoldo

    2013-01-01

    The nematophagous fungus Pochonia chlamydosporia var. chlamydosporia is one of the most studied biological control agents against plant (semi-) endo-parasitic nematodes of the genera Globodera, Heterodera, Meloidogyne, Nacobbus and, more recently, Rotylenchulus. In this paper we present highlights from more than three decades of worldwide research on this biological control agent. We cover different aspects and key components of the complex plant-fungus-nematode tri-trophic interaction, an interaction that needs to be addressed to ensure the efficient use of P. chlamydosporia as a biopesticide as part of an integrated pest management approach. PMID:23589653

  1. Comparative analysis of macrophage migration inhibitory factors (MIFs) from the parasitic nematode Onchocerca volvulus and the free-living nematode Caenorhabditis elegans.

    PubMed

    Ajonina-Ekoti, Irene; Kurosinski, Marc Andre; Younis, Abuelhassan Elshazly; Ndjonka, Dieudonne; Tanyi, Manchang Kingsley; Achukwi, Mbunkah; Eisenbarth, Albert; Ajonina, Caroline; Lüersen, Kai; Breloer, Minka; Brattig, Norbert W; Liebau, Eva

    2013-09-01

    The macrophage migration inhibitory factors (MIFs) from the filarial parasite Onchocerca volvulus (OvMIF) were compared to the MIFs from the free-living nematode Caenorhabditis elegans (CeMIF) with respect to molecular, biochemical and immunological properties. Except for CeMIF-4, all other MIFs demonstrated tautomerase activity. Surprisingly, OvMIF-1 displayed oxidoreductase activity. The strongest immunostaining for OvMIF-1 was observed in the outer cellular covering of the adult worm body, the syncytial hypodermis; moderate immunostaining was observed in the uterine wall. The generation of a strong humoral immune response towards OvMIF-1 and reduced reactivity to OvMIF-2 was indicated by high IgG levels in patients infected with O. volvulus and cows infected with the closely related Onchocerca ochengi, both MIFs revealing identical amino acid sequences. Using Litomosoides sigmodontis-infected mice, a laboratory model for filarial infection, MIFs derived from the tissue-dwelling O. volvulus, the rodent gut-dwelling Strongyloides ratti and from free-living C. elegans were recognized, suggesting that L. sigmodontis MIF-specific IgM and IgG1 were produced during L. sigmodontis infection of mice and cross-reacted with all MIF proteins tested. Thus, MIF apparently functions as a target of B cell response during nematode infection, but in the natural Onchocerca-specific human and bovine infection, the induced antibodies can discriminate between MIFs derived from parasitic or free-living nematodes. PMID:23820606

  2. Manipulation of auxin transport in plant roots during Rhizobium symbiosis and nematode parasitism.

    PubMed

    Grunewald, Wim; van Noorden, Giel; Van Isterdael, Gert; Beeckman, Tom; Gheysen, Godelieve; Mathesius, Ulrike

    2009-09-01

    The plant rhizosphere harbors many different microorganisms, ranging from plant growth-promoting bacteria to devastating plant parasites. Some of these microbes are able to induce de novo organ formation in infected roots. Certain soil bacteria, collectively called rhizobia, form a symbiotic interaction with legumes, leading to the formation of nitrogen-fixing root nodules. Sedentary endoparasitic nematodes, on the other hand, induce highly specialized feeding sites in infected plant roots from which they withdraw nutrients. In order to establish these new root structures, it is thought that these organisms use and manipulate the endogenous molecular and physiological pathways of their hosts. Over the years, evidence has accumulated reliably demonstrating the involvement of the plant hormone auxin. Moreover, the auxin responses during microbe-induced de novo organ formation seem to be dynamic, suggesting that plant-associated microbes can actively modify their host's auxin transport. In this review, we focus on recent findings in auxin transport mechanisms during plant development and on how plant symbionts and parasites have evolved to manipulate these mechanisms for their own purposes.

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

    PubMed

    Moravec, Frantisek; de Buron, Isaure

    2013-05-01

    Members of the Philometridae represent the most important group of dracunculoid nematodes parasitizing fishes. In his monograph treating the Dracunculoidea, Moravec (2006) reported a total of 11 genera and 105 species of philometrids parasitizing freshwater, brackish-water and marine fishes. However, during the last six years (2007-2012), an additional 42 new species of Philometridae have been described, representing a 40% increase of the number of nominal species. Most of these species (30) belong to Philometra Costa, 1845, mainly represented by parasites of marine fishes, a few others (8) to Philometroides Yamaguti, 1935, and a single one to each of the following genera: Caranginema Moravec, Montoya-Mendoza et Salgado-Maldonado, 2008, Dentiphilometra Moravec et Wang, 2002, Dentirumai Quiazon et Moravec, 2013* and Spirophilometra Parukhin, 1971. Moreover, three new genera, Afrophilometra Moravec, Charo-Karisa et Jirků, 2009, Caranginema and Dentirumai, were erected. Representatives of seven genera, Afrophilometra, Buckleyella Rasheed, 1963, Caranginema, Dentiphilometra, Dentirumai, Paraphilometroides Moravec et Shaharom-Harrison, 1989 and Rumai Travassos, 1960, were studied using scanning electron microscopy (SEM) for the first time. Thirteen known but poorly described philometrid species were redescribed and, in some species of Caranginema and Philometra, previously unknown conspecific males were discovered and described. The male surface ultrastructure studied by SEM provided new taxonomically important features for species distinction. Gene sequencing was used in several recent studies and advanced our understanding of phylogenetic interrelationships among representatives of seven genera (Afrophilometra, Alinema Rasheed, 1963, Caranginema, Nilonema Khalil, 1960, Philometra, Philometroides and Rumai) and of the extent of the biodiversity of philometrids. New data were obtained on the biology and pathogenicity of several species of Nilonema, Philometra

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

    PubMed

    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.

  5. Population genomics of the filarial nematode parasite Wuchereria bancrofti from mosquitoes.

    PubMed

    Small, Scott T; Reimer, Lisa J; Tisch, Daniel J; King, Christopher L; Christensen, Bruce M; Siba, Peter M; Kazura, James W; Serre, David; Zimmerman, Peter A

    2016-04-01

    Wuchereria bancrofti is a parasitic nematode and the primary cause of lymphatic filariasis--a disease specific to humans. W. bancrofti currently infects over 90 million people throughout the tropics and has been acknowledged by the world health organization as a vulnerable parasite. Current research has focused primarily on the clinical manifestations of disease and little is known about the evolutionary history of W. bancrofti. To improve upon knowledge of the evolutionary history of W. bancrofti, we whole genome sequenced 13 W. bancrofti larvae. We circumvent many of the difficulties of multiple infections by sampling larvae directly from mosquitoes that were experimentally inoculated with infected blood. To begin, we used whole genome data to reconstruct the historical population size. Our results support a history of fluctuating population sizes that can be correlated with human migration and fluctuating mosquito abundances. Next, we reconstructed the putative pedigree of W. bancrofti worms within an infection using the kinship coefficient. We deduced that there are full-sib and half-sib relationships residing within the same larval cohort. Through combined analysis of the mitochondrial and nuclear genomes we concluded that this is likely a results of polyandrous mating, the first time reported for W. bancrofti. Lastly, we scanned the genomes for signatures of natural selection. Annotation of putative selected regions identified proteins that may have aided in a parasitic life style or may have evolved to protect against current drug treatments. We discuss our results in the greater context of understanding the biology of an animal with a unique life history and ecology. PMID:26850696

  6. Glucose and Glycogen Metabolism in Brugia malayi Is Associated with Wolbachia Symbiont Fitness.

    PubMed

    Voronin, Denis; Bachu, Saheed; Shlossman, Michael; Unnasch, Thomas R; Ghedin, Elodie; Lustigman, Sara

    2016-01-01

    Wolbachia are endosymbiotic bacteria found in the majority of arthropods and filarial nematodes of medical and veterinary importance. They have evolved a wide range of symbiotic associations. In filarial nematodes that cause human lymphatic filariasis (Wuchereria bancrofti, Brugia malayi) or onchocerciasis (Onchocerca volvulus), Wolbachia are important for parasite development, reproduction and survival. The symbiotic bacteria rely in part on nutrients and energy sources provided by the host. Genomic analyses suggest that the strain of Wolbachia found in B. malayi (wBm) lacks the genes for two glycolytic enzymes--6-phosphofructokinase and pyruvate kinase--and is thus potentially unable to convert glucose into pyruvate, an important substrate for energy generation. The Wolbachia surface protein, wBm00432, is complexed to six B. malayi glycolytic enzymes, including aldolase. In this study we characterized two B. malayi aldolase isozymes and found that their expression is dependent on Wolbachia fitness and number. We confirmed by immuno-transmission electron microscopy that aldolase is associated with the Wolbachia surface. RNAi experiments suggested that aldolase-2 plays a significant role in both Wolbachia survival and embryogenesis in B. malayi. Treatment with doxycycline reduced Wolbachia fitness and increased the amount of both glucose and glycogen detected in the filarial parasite, indicating that glucose metabolism and glycogen storage in B. malayi are associated with Wolbachia fitness. This metabolic co-dependency between Wolbachia and its filarial nematode indicates that glycolysis could be a shared metabolic pathway between the bacteria and B. malayi, and thus a potential new target for anti-filarial therapy. PMID:27078260

  7. Glucose and Glycogen Metabolism in Brugia malayi Is Associated with Wolbachia Symbiont Fitness

    PubMed Central

    Voronin, Denis; Bachu, Saheed; Shlossman, Michael; Unnasch, Thomas R.; Ghedin, Elodie; Lustigman, Sara

    2016-01-01

    Wolbachia are endosymbiotic bacteria found in the majority of arthropods and filarial nematodes of medical and veterinary importance. They have evolved a wide range of symbiotic associations. In filarial nematodes that cause human lymphatic filariasis (Wuchereria bancrofti, Brugia malayi) or onchocerciasis (Onchocerca volvulus), Wolbachia are important for parasite development, reproduction and survival. The symbiotic bacteria rely in part on nutrients and energy sources provided by the host. Genomic analyses suggest that the strain of Wolbachia found in B. malayi (wBm) lacks the genes for two glycolytic enzymes—6-phosphofructokinase and pyruvate kinase—and is thus potentially unable to convert glucose into pyruvate, an important substrate for energy generation. The Wolbachia surface protein, wBm00432, is complexed to six B. malayi glycolytic enzymes, including aldolase. In this study we characterized two B. malayi aldolase isozymes and found that their expression is dependent on Wolbachia fitness and number. We confirmed by immuno-transmission electron microscopy that aldolase is associated with the Wolbachia surface. RNAi experiments suggested that aldolase-2 plays a significant role in both Wolbachia survival and embryogenesis in B. malayi. Treatment with doxycycline reduced Wolbachia fitness and increased the amount of both glucose and glycogen detected in the filarial parasite, indicating that glucose metabolism and glycogen storage in B. malayi are associated with Wolbachia fitness. This metabolic co-dependency between Wolbachia and its filarial nematode indicates that glycolysis could be a shared metabolic pathway between the bacteria and B. malayi, and thus a potential new target for anti-filarial therapy. PMID:27078260

  8. [Biological cycle of Cyrnea (Procyrnea) mansoni Seurat, 1914, a habronemid nematode parasite of birds of prey in Togo].

    PubMed

    Quentin, J C; Seureau, C; Railhac, C

    1983-01-01

    A habronemid nematode in birds of prey, Milvus migrans Bonaparti and Accipiter badius Linné, in Togo, is identified as Cyrnea (Procyrnea) mansioni (Seurat, 1914). Larval development is experimentally studied in the orthopteran Acrididae Tylotropidius patagiatus Karsch. The first three larval stages are described and illustrated. The biology of this spiruroid nematode is distinguished by the unusual rapidity of larval development (infective larvae at 10 days). Comparison of the life cycle of C. mansioni with life cycles of other Habronemid Nematodes parasitizing birds, points out an evolution of larvae from primitive forms of large size and slow development to evolved forms of small size and rapid development. Observations concerning the encapsulation of infective larvae in the intermediate host confirm this larval evolution. PMID:6625469

  9. Parasites of South African freshwater fish. VII. Nematodes of some scaled fishes from the Hartbeespoort Dam, Transvaal.

    PubMed

    Boomker, J

    1994-06-01

    The nematode parasites of 16 large-scaled yellowfish, Barbus marequensis, six silverfish, Barbus mattozi, six small-scaled yellowfish, Barbus polylepis, 52 canary kurper, Chetia flaviventris, 11 carp, Cyprinus carpio, 45 Mozambique bream, Oreochromis mossambicus and a single-banded bream, Tilapia sparrmani, caught in the Hartbeespoort Dam, Transvaal, were collected, identified and counted. Contracaecum spp. larvae were recovered from one O. mossambicus, 40 Chetia flaviventris, three Cyprinus carpio, one B. marequensis and five B. mattozi, Rhabdochona esseniae from five B. marequensis, Rhabdochona spp. from one O. mossambicus and four Cyprinus carpio, and unidentified nematode larvae from two O. mossambicus, three Chetia flaviventris, two Cyprinus carpio and from the single T. sparrmani. Burdens in the infected fishes were generally small, and small-scaled yellowfish did not harbour any worms. Only Mozambique bream and canary kurper were caught at regular intervals, but even in these species no pattern of seasonal prevalence of the nematodes was evident. PMID:7596571

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

    SciTech Connect

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

    2007-03-15

    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) [Spanish] Los grillotopos invasores no indigenas, Scapteriscus vicinus (Orthoptera: Gryllotalpidae) en el estado de Florida y S. didactylus ('changa') en Puerto Rico, estan siendo manejados por el nematodo entomopathogeno, Steinernema scapterisci (Rhabditida: Steinernematidae) y la avispa parasitica, Larra bicolor (Hymenoptera: Sphecidae). Las poblaciones de los grillotopo plagas han declinado un 95% en el norte central de la Florida desde que estos enemigos naturales especialistas

  11. First Report of Korean Cyst Nematode, Heterodera koreana, Parasitic on Bamboo, Phyllostachys nigra, from Iran

    PubMed Central

    Maafi, Zahra Tanha; Taheri, Zahra Majd

    2015-01-01

    Bamboo is grown sporadically in the north of Iran and is confined to very limited areas. The history of growing bamboo was to some extent simultaneous with the entrance, commencement, and growth of the tea industry in the north about a century ago. The bamboo was used for making baskets to transfer the harvested tea foliage from farm to the factory and other linked functions. A main area allocated for bamboo growing is located in Lahidjan Agricultural Research Station (LARS) in the north of Iran, where several species of bamboo were cultivated in an area of 5 ha. The species include five species of Phyllostachys (viz., P. aurea, P. bambusoides, P. decora, P. nigra, P. vivax) and one species of Arundinaria gigantean, Pleioblastus fortune, and Semiarundinaria fastuosa; however, only P. aurea and P. nigra have been precisely identified. A survey on plant parasitic nematodes associated with bamboo mainly on P. nigra in LARS revealed second-stage juveniles of cyst forming nematode in soil samples. Further analysis of root and soil samples led to recovery of a cyst nematode belonging to the genus Heterodera and the Afenestrata group. Cysts, vulval cone, and second-stage juveniles were studied for morphological and morphometric features. The classical identification was followed by amplification of the ribosomal RNA-ITS region and the D2-D3 expansion segments of 28S large-subunit rRNA gene; the amplified fragments were sequenced, edited, and compared with those of the corresponding published gene sequences. New D2-D3 and rRNA-ITS gene sequences were deposited in the GenBank database under the accession numbers KR818910 and KR818911, respectively. Based on the morphological and molecular data, the species of the cyst-forming nematode was identified as H. koreana (Vovlas et al., 1992; Mundo-Ocampo et al., 2008). The body contour of cysts was mainly subspherical, vey often with irregular shape (Fig. 1A), yellowish to light brown, thin cuticle with fine zigzag pattern

  12. First Report of Korean Cyst Nematode, Heterodera koreana, Parasitic on Bamboo, Phyllostachys nigra, from Iran.

    PubMed

    Maafi, Zahra Tanha; Taheri, Zahra Majd

    2015-09-01

    Bamboo is grown sporadically in the north of Iran and is confined to very limited areas. The history of growing bamboo was to some extent simultaneous with the entrance, commencement, and growth of the tea industry in the north about a century ago. The bamboo was used for making baskets to transfer the harvested tea foliage from farm to the factory and other linked functions. A main area allocated for bamboo growing is located in Lahidjan Agricultural Research Station (LARS) in the north of Iran, where several species of bamboo were cultivated in an area of 5 ha. The species include five species of Phyllostachys (viz., P. aurea, P. bambusoides, P. decora, P. nigra, P. vivax) and one species of Arundinaria gigantean, Pleioblastus fortune, and Semiarundinaria fastuosa; however, only P. aurea and P. nigra have been precisely identified. A survey on plant parasitic nematodes associated with bamboo mainly on P. nigra in LARS revealed second-stage juveniles of cyst forming nematode in soil samples. Further analysis of root and soil samples led to recovery of a cyst nematode belonging to the genus Heterodera and the Afenestrata group. Cysts, vulval cone, and second-stage juveniles were studied for morphological and morphometric features. The classical identification was followed by amplification of the ribosomal RNA-ITS region and the D2-D3 expansion segments of 28S large-subunit rRNA gene; the amplified fragments were sequenced, edited, and compared with those of the corresponding published gene sequences. New D2-D3 and rRNA-ITS gene sequences were deposited in the GenBank database under the accession numbers KR818910 and KR818911, respectively. Based on the morphological and molecular data, the species of the cyst-forming nematode was identified as H. koreana (Vovlas et al., 1992; Mundo-Ocampo et al., 2008). The body contour of cysts was mainly subspherical, vey often with irregular shape (Fig. 1A), yellowish to light brown, thin cuticle with fine zigzag pattern

  13. Analysis of Nematode Motion Using an Improved Light-Scatter Based System

    PubMed Central

    Nutting, Chuck S.; Eversole, Rob R.; Blair, Kevin; Specht, Sabine; Nutman, Thomas B.; Klion, Amy D.; Wanji, Samuel; Boussinesq, Michel; Mackenzie, Charles D.

    2015-01-01

    Background 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. Methods 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. Results The motion of worms in a small (200ul) volume can be detected, with the presence of immotile worms not interfering with the readings at practical levels (up to at least 500 L1 /200ul). 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. Conclusions 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. PMID:25695776

  14. Adaptive Radiation within Marine Anisakid Nematodes: A Zoogeographical Modeling of Cosmopolitan, Zoonotic Parasites

    PubMed Central

    Kuhn, Thomas; García-Màrquez, Jaime; Klimpel, Sven

    2011-01-01

    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. PMID:22180787

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

    PubMed Central

    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

  16. Molecular genomics resource for the parasitic nematode Spirocerca lupi: Identification of 149 microsatellite loci using FIASCO and next generation sequencing.

    PubMed

    Reid, Kerry; Mitha, Janishtha R; Greeff, Jaco M; de Waal, Pamela J

    2015-01-01

    Understanding genetic diversity and movement patterns in parasitic organisms is paramount to establish control and management strategies. In this study we developed a microsatellite resource as well as a diagnostic multiplex for the cosmopolitan parasitic nematode Spirocerca lupi, known to cause spirocercosis in canids. A combination of microsatellite enrichment and 454 sequencing was used to identify 149 unique microsatellite loci in S. lupi. Twenty loci were characterized further in two sampling sites in South Africa, with 10 loci identified as polymorphic (allele ranges from 4 to 17). These loci were designed into a single diagnostic multiplex suitable for species identification and population genetics studies. The markers were also successful in cross-species amplification in Cylicospirura felineus, Philonema oncorhynchi and Gongylonema pulchrum. Our resource provides a large set of candidate loci for a number of nematode studies as well as loci suitable for diversity and population genetics studies of S. lupi within the South African context as well as globally.

  17. Mechanisms of Molecular Mimicry of Plant CLE Peptide Ligands by the Parasitic Nematode Globodera rostochiensis1[C][W

    PubMed Central

    Guo, Yongfeng; Ni, Jun; Denver, Robert; Wang, Xiaohong; Clark, Steven E.

    2011-01-01

    Nematodes that parasitize plant roots cause huge economic losses and have few mechanisms for control. Many parasitic nematodes infect plants by reprogramming root development to drive the formation of feeding structures. How nematodes take control of plant development is largely unknown. Here, we identify two host factors involved in the function of a receptor ligand mimic, GrCLE1, secreted by the potato cyst nematode Globodera rostochiensis. GrCLE1 is correctly processed to an active form by host plant proteases. Processed GrCLE1 peptides bind directly to the plant CLE receptors CLV2, BAM1, and BAM2. Involvement of these receptors in the ligand-mimicking process is also supported by the fact that the ability of GrCLE1 peptides to alter plant root development in Arabidopsis (Arabidopsis thaliana) is dependent on these receptors. Critically, we also demonstrate that GrCLE1 maturation can be entirely carried out by plant factors and that the availability of CLE processing activity may be essential for successful ligand mimicry. PMID:21750229

  18. Genetic structure and parasitization-related ability divergence of a nematode fungal pathogen Hirsutella minnesotensis following founder effect in China.

    PubMed

    Shu, Chi; Jiang, Xianzhi; Cheng, Xiaoli; Wang, Niuniu; Chen, Senyu; Xiang, Meichun; Liu, Xingzhong

    2015-08-01

    The fungal parasitoid, Hirsutella minnesotensis, is a dominant parasitoid of the soybean cyst nematode, which is a destruction pest of soybean crops. We investigated population structure and parasitism pattern in samples of H. minnesotensis in China to reveal the spreading pattern of this fungal species and the underlying mechanism generating the parasitization-related ability variability in Chinese population. In cross-inoculation experiments using different combinations of H. minnesotensis and soybean cyst nematode samples from China, most H. minnesotensis isolates fitted the criterion for "local versus foreign" parasitism profile, exhibiting local adaptation pattern to the SCN host. However, the genetic analysis of the single nucleotide polymorphisms with clone-corrected samples based on ten DNA fragments in 56 isolates of H. minnesotensis from China revealed that the Chinese H. minnesotensis population was a clonal lineage that underwent a founder event. The results demonstrated that the Chinese H. minnesotensis population had generated parasitization-related ability diversity after a founder event through individual variation or phenotypic plasticity other than local adaptation. The rapid divergence of parasitization-related abilities with simple genetic structure in Chinese H. minnesotensis population indicates a fundamental potential for the establishment of invasive fungal species, which is a prerequisite for biological control agents.

  19. Deletion of Parasite Immune Modulatory Sequences Combined with Immune Activating Signals Enhances Vaccine Mediated Protection against Filarial Nematodes

    PubMed Central

    Babayan, Simon A.; Luo, HongLin; Gray, Nick; Taylor, David W.; Allen, Judith E.

    2012-01-01

    Background Filarial nematodes are tissue-dwelling parasites that can be killed by Th2-driven immune effectors, but that have evolved to withstand immune attack and establish chronic infections by suppressing host immunity. As a consequence, the efficacy of a vaccine against filariasis may depend on its capacity to counter parasite-driven immunomodulation. Methodology and Principal Findings We immunised mice with DNA plasmids expressing functionally-inactivated forms of two immunomodulatory molecules expressed by the filarial parasite Litomosoides sigmodontis: the abundant larval transcript-1 (LsALT) and cysteine protease inhibitor-2 (LsCPI). The mutant proteins enhanced antibody and cytokine responses to live parasite challenge, and led to more leukocyte recruitment to the site of infection than their native forms. The immune response was further enhanced when the antigens were targeted to dendritic cells using a single chain Fv-αDEC205 antibody and co-administered with plasmids that enhance T helper 2 immunity (IL-4) and antigen-presenting cell recruitment (Flt3L, MIP-1α). Mice immunised simultaneously against the mutated forms of LsALT and LsCPI eliminated adult parasites faster and consistently reduced peripheral microfilaraemia. A multifactorial analysis of the immune response revealed that protection was strongly correlated with the production of parasite-specific IgG1 and with the numbers of leukocytes present at the site of infection. Conclusions We have developed a successful strategy for DNA vaccination against a nematode infection that specifically targets parasite-driven immunosuppression while simultaneously enhancing Th2 immune responses and parasite antigen presentation by dendritic cells. PMID:23301106

  20. How to become a parasite without sex chromosomes: a hypothesis for the evolution of Strongyloides spp. and related nematodes.

    PubMed

    Streit, Adrian

    2014-09-01

    Parasitic lifestyles evolved many times independently. Just within the phylum Nematoda animal parasitism must have arisen at least four times. Switching to a parasitic lifestyle is expected to lead to changes in various life history traits including reproductive strategies. Parasitic nematode worms of the genus Strongyloides represent an interesting example to study these processes because they are still capable of forming facultative free-living generations in between parasitic ones. The parasitic generation consists of females only, which reproduce parthenogenetically. The sex in the progeny of the parasitic worms is determined by environmental cues, which control a, presumably ancestral, XX/XO chromosomal sex determining system. In some species the X chromosome is fused with an autosome and one copy of the X-derived sequences is removed by sex-specific chromatin diminution in males. Here I propose a hypothesis for how today's Strongyloides sp. might have evolved from a sexual free-living ancestor through dauer larvae forming free-living and facultative parasitic intermediate stages. PMID:24829037

  1. Expression of nicotinic acetylcholine receptor subunits from parasitic nematodes in Caenorhabditis elegans.

    PubMed

    Sloan, Megan A; Reaves, Barbara J; Maclean, Mary J; Storey, Bob E; Wolstenholme, Adrian J

    2015-11-01

    The levamisole-sensitive nicotinic acetylcholine receptor present at nematode neuromuscular junctions is composed of multiple different subunits, with the exact composition varying between species. We tested the ability of two well-conserved nicotinic receptor subunits, UNC-38 and UNC-29, from Haemonchus contortus and Ascaris suum to rescue the levamisole-resistance and locomotion defects of Caenorhabditis elegans strains with null deletion mutations in the unc-38 and unc-29 genes. The parasite cDNAs were cloned downstream of the relevant C. elegans promoters and introduced into the mutant strains via biolistic transformation. The UNC-38 subunit of H. contortus was able to completely rescue both the locomotion defects and levamisole resistance of the null deletion mutant VC2937 (ok2896), but no C. elegans expressing the A. suum UNC-38 could be detected. The H. contortus UNC-29.1 subunit partially rescued the levamisole resistance of a C. elegans null mutation in unc-29 VC1944 (ok2450), but did cause increased motility in a thrashing assay. In contrast, only a single line of worms containing the A. suum UNC-29 subunit showed a partial rescue of levamisole resistance, with no effect on thrashing.

  2. Ivermectin disrupts the function of the excretory-secretory apparatus in microfilariae of Brugia malayi.

    PubMed

    Moreno, Yovany; Nabhan, Joseph F; Solomon, Jonathan; Mackenzie, Charles D; Geary, Timothy G

    2010-11-16

    Ivermectin (IVM) is a broad-spectrum anthelmintic used in filariasis control programs. By binding to nematode glutamate-gated chloride channels (GluCls), IVM disrupts neurotransmission processes regulated by GluCl activity. IVM treatment of filarial infections is characterized by an initial dramatic drop in the levels of circulating microfilariae, followed by long-term suppression of their production, but the drug has little direct effect on microfilariae in culture at pharmacologically relevant concentrations. We localized Brugia malayi GluCl expression solely in a muscle structure that surrounds the microfilarial excretory-secretory (ES) vesicle, which suggests that protein release from the ES vesicle is regulated by GluCl activity. Consistent with this hypothesis, exposure to IVM in vitro decreased the amount of protein released from microfilariae. To better understand the scope of IVM effects on protein release by the parasite, three different expression patterns were identified from immunolocalization assays on a representative group of five microfilarial ES products. Patterns of expression suggest that the ES apparatus is the main source of regulated ES product release from microfilariae, as it is the only compartment that appears to be under neuromuscular control. Our results show that IVM treatment of microfilariae results in a marked reduction of protein release from the ES apparatus. Under in vivo conditions, the rapid microfilarial clearance induced by IVM treatment is proposed to result from suppression of the ability of the parasite to secrete proteins that enable evasion of the host immune system.

  3. The Cyst Nematode Effector Protein 10A07 Targets and Recruits Host Posttranslational Machinery to Mediate Its Nuclear Trafficking and to Promote Parasitism in Arabidopsis

    PubMed Central

    Hewezi, Tarek; Juvale, Parijat S.; Piya, Sarbottam; Maier, Tom R.; Rambani, Aditi; Rice, J. Hollis; Mitchum, Melissa G.; Davis, Eric L.; Hussey, Richard S.; Baum, Thomas J.

    2015-01-01

    Plant-parasitic cyst nematodes synthesize and secrete effector proteins that are essential for parasitism. One such protein is the 10A07 effector from the sugar beet cyst nematode, Heterodera schachtii, which is exclusively expressed in the nematode dorsal gland cell during all nematode parasitic stages. Overexpression of H. schachtii 10A07 in Arabidopsis thaliana produced a hypersusceptible phenotype in response to H. schachtii infection along with developmental changes reminiscent of auxin effects. The 10A07 protein physically associates with a plant kinase and the IAA16 transcription factor in the cytoplasm and nucleus, respectively. The interacting plant kinase (IPK) phosphorylates 10A07 at Ser-144 and Ser-231 and mediates its trafficking from the cytoplasm to the nucleus. Translocation to the nucleus is phosphorylation dependent since substitution of Ser-144 and Ser-231 by alanine resulted in exclusive cytoplasmic accumulation of 10A07. IPK and IAA16 are highly upregulated in the nematode-induced syncytium (feeding cells), and deliberate manipulations of their expression significantly alter plant susceptibility to H. schachtii in an additive fashion. An inactive variant of IPK functioned antagonistically to the wild-type IPK and caused a dominant-negative phenotype of reduced plant susceptibility. Thus, exploitation of host processes to the advantage of the parasites is one mechanism by which cyst nematodes promote parasitism of host plants. PMID:25715285

  4. The cyst nematode effector protein 10A07 targets and recruits host posttranslational machinery to mediate its nuclear trafficking and to promote parasitism in Arabidopsis.

    PubMed

    Hewezi, Tarek; Juvale, Parijat S; Piya, Sarbottam; Maier, Tom R; Rambani, Aditi; Rice, J Hollis; Mitchum, Melissa G; Davis, Eric L; Hussey, Richard S; Baum, Thomas J

    2015-03-01

    Plant-parasitic cyst nematodes synthesize and secrete effector proteins that are essential for parasitism. One such protein is the 10A07 effector from the sugar beet cyst nematode, Heterodera schachtii, which is exclusively expressed in the nematode dorsal gland cell during all nematode parasitic stages. Overexpression of H. schachtii 10A07 in Arabidopsis thaliana produced a hypersusceptible phenotype in response to H. schachtii infection along with developmental changes reminiscent of auxin effects. The 10A07 protein physically associates with a plant kinase and the IAA16 transcription factor in the cytoplasm and nucleus, respectively. The interacting plant kinase (IPK) phosphorylates 10A07 at Ser-144 and Ser-231 and mediates its trafficking from the cytoplasm to the nucleus. Translocation to the nucleus is phosphorylation dependent since substitution of Ser-144 and Ser-231 by alanine resulted in exclusive cytoplasmic accumulation of 10A07. IPK and IAA16 are highly upregulated in the nematode-induced syncytium (feeding cells), and deliberate manipulations of their expression significantly alter plant susceptibility to H. schachtii in an additive fashion. An inactive variant of IPK functioned antagonistically to the wild-type IPK and caused a dominant-negative phenotype of reduced plant susceptibility. Thus, exploitation of host processes to the advantage of the parasites is one mechanism by which cyst nematodes promote parasitism of host plants.

  5. The cyst nematode effector protein 10A07 targets and recruits host posttranslational machinery to mediate its nuclear trafficking and to promote parasitism in Arabidopsis.

    PubMed

    Hewezi, Tarek; Juvale, Parijat S; Piya, Sarbottam; Maier, Tom R; Rambani, Aditi; Rice, J Hollis; Mitchum, Melissa G; Davis, Eric L; Hussey, Richard S; Baum, Thomas J

    2015-03-01

    Plant-parasitic cyst nematodes synthesize and secrete effector proteins that are essential for parasitism. One such protein is the 10A07 effector from the sugar beet cyst nematode, Heterodera schachtii, which is exclusively expressed in the nematode dorsal gland cell during all nematode parasitic stages. Overexpression of H. schachtii 10A07 in Arabidopsis thaliana produced a hypersusceptible phenotype in response to H. schachtii infection along with developmental changes reminiscent of auxin effects. The 10A07 protein physically associates with a plant kinase and the IAA16 transcription factor in the cytoplasm and nucleus, respectively. The interacting plant kinase (IPK) phosphorylates 10A07 at Ser-144 and Ser-231 and mediates its trafficking from the cytoplasm to the nucleus. Translocation to the nucleus is phosphorylation dependent since substitution of Ser-144 and Ser-231 by alanine resulted in exclusive cytoplasmic accumulation of 10A07. IPK and IAA16 are highly upregulated in the nematode-induced syncytium (feeding cells), and deliberate manipulations of their expression significantly alter plant susceptibility to H. schachtii in an additive fashion. An inactive variant of IPK functioned antagonistically to the wild-type IPK and caused a dominant-negative phenotype of reduced plant susceptibility. Thus, exploitation of host processes to the advantage of the parasites is one mechanism by which cyst nematodes promote parasitism of host plants. PMID:25715285

  6. Conserved miRNAs are candidate post-transcriptional regulators of developmental arrest in free-living and parasitic nematodes.

    PubMed

    Ahmed, Rina; Chang, Zisong; Younis, Abuelhassan Elshazly; Langnick, Claudia; Li, Na; Chen, Wei; Brattig, Norbert; Dieterich, Christoph

    2013-01-01

    Animal development is complex yet surprisingly robust. Animals may develop alternative phenotypes conditional on environmental changes. Under unfavorable conditions, Caenorhabditis elegans larvae enter the dauer stage, a developmentally arrested, long-lived, and stress-resistant state. Dauer larvae of free-living nematodes and infective larvae of parasitic nematodes share many traits including a conserved endocrine signaling module (DA/DAF-12), which is essential for the formation of dauer and infective larvae. We speculated that conserved post-transcriptional regulatory mechanism might also be involved in executing the dauer and infective larvae fate. We used an unbiased sequencing strategy to characterize the microRNA (miRNA) gene complement in C. elegans, Pristionchus pacificus, and Strongyloides ratti. Our study raised the number of described miRNA genes to 257 for C. elegans, tripled the known gene set for P. pacificus to 362 miRNAs, and is the first to describe miRNAs in a Strongyloides parasite. Moreover, we found a limited core set of 24 conserved miRNA families in all three species. Interestingly, our estimated expression fold changes between dauer versus nondauer stages and infective larvae versus free-living stages reveal that despite the speed of miRNA gene set evolution in nematodes, homologous gene families with conserved "dauer-infective" expression signatures are present. These findings suggest that common post-transcriptional regulatory mechanisms are at work and that the same miRNA families play important roles in developmental arrest and long-term survival in free-living and parasitic nematodes.

  7. Genetic diversity and infection levels of anisakid nematodes parasitic in fish and marine mammals from Boreal and Austral hemispheres.

    PubMed

    Mattiucci, Simonetta; Nascetti, Giuseppe

    2007-08-19

    Anisakid nematodes have complex life-cycles that include invertebrate and vertebrate hosts at various levels of the marine food chain. Different types of habitat disturbances of the marine ecosystem (pollution, overfishing, by-catch) could impoverish the host population size, resulting in concomitant and detrimental effects on parasitic nematode populations. This in turn would lead to the loss of genetic diversity of these parasites at both the species and population levels. In order to test for a correlation existing between the genetic diversity of anisakid nematodes and habitat disturbance, the genetic variability, estimated by nuclear markers (19 allozyme loci), was evaluated among several anisakid populations from fish and marine mammals in various areas of the Boreal and Austral regions. Antarctic and sub-antarctic populations showed significantly (P<0.001) higher levels of genetic diversity (on average, He=0.23) than those from the Arctic and sub-Arctic populations and species (on average, He=0.07). Correlations between the degree of genetic variability and the levels of parasitic infections within their hosts were considered. Data revealed higher intensities in anisakid infections in Antarctic and sub-Antarctic hosts, presumably resulting from a lower degree of habitat disturbance in less stressed areas. The absence of disturbance presumably allowed anisakid species to reach a larger population size, with a reduced probability of genetic drift in their gene pools. This suggests that anisakid nematodes, and their levels of genetic diversity may be suitable indicators of the integrity of marine food webs and of the general biodiversity of a marine ecosystem.

  8. The contribution of molecular biology to the development of vaccines against nematode and trematode parasites of domestic ruminants.

    PubMed

    Knox, D P; Redmond, D L; Skuce, P J; Newlands, G F

    2001-11-22

    Rapid developments in molecular biology have had an enormous impact on the prospects for the development of vaccines to control the major nematode and trematode infestations of livestock. Vaccine candidates are purified using conventional protein chemistry techniques but the limitations imposed by the scarcity of parasite material provide an insurmountable barrier for commercial vaccine production by this means. The ability to purify mRNA from different parasite life-cycle stages and to prepare cDNA expression libraries from it has proven central to the identification of immunogenic parasite proteins. Potentially, protective parasite antigens can now be produced in recombinant form in a variety of vectors and this represents a key breakthrough on the road to commercial vaccine production. The contribution of molecular biology to this process is discussed using several examples, particularly in vaccine development against the pathogenic abomasal nematode of sheep and goats, Haemonchus contortus, and the liver fluke of sheep and cattle, Fasciola hepatica. The difficulties of producing recombinant proteins in the correct form, with appropriate post-translational modification and conformation, are discussed as well as emerging means of antigen delivery including DNA vaccination. The opportunities offered by genome and expressed sequence tag analyses programmes for antigen targeting are discussed in association with developing microarray and proteomics technologies which offer the prospect of large scale, rapid antigen screening and identification.

  9. Nematodes parasites of the gray fox (Urocyon cinereoargenteus Schreber, 1775) in the seasonally dry tropical highlands of central Mexico.

    PubMed

    Hernández-Camacho, Norma; Pineda-López, Raul; López-González, Carlos A; Jones, Robert W

    2011-06-01

    The gray fox (Urocyon cinereoargenteus Schreber, 1775) is the most abundant and opportunistic wild canid in Mexico. However, the parasites of this canid in Mexico are poorly known, and an intensive parasite survey is lacking. A survey of gray fox parasitological feces was conducted in El Cimatario National Park, a protected area representative of the seasonally dry, tropical highlands of Mexico. Feces were collected in six 1-km-length transects during the summer of 2003 and spring of 2004. The coproparasitoscopical survey registered nine species of nematodes, typical of wild and domestic canids such as Strongyloides stercoralis, Uncinaria stenocephala, Toxocara canis, Toxascaris leonina, Dioctophyme renale, Trichuris vulpis, Trichuris sp., and Capillaria sp. Ecological factors such as temperature and humidity appear to play a more important role in the establishment of these species of parasites in this protected area than the presence of domestic dogs.

  10. Pan-phylum Comparison of Nematode Metabolic Potential

    PubMed Central

    Tyagi, Rahul; Rosa, Bruce A.; Lewis, Warren G.; Mitreva, Makedonka

    2015-01-01

    Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in

  11. Pan-phylum Comparison of Nematode Metabolic Potential.

    PubMed

    Tyagi, Rahul; Rosa, Bruce A; Lewis, Warren G; Mitreva, Makedonka

    2015-05-01

    Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in

  12. Pan-phylum Comparison of Nematode Metabolic Potential.

    PubMed

    Tyagi, Rahul; Rosa, Bruce A; Lewis, Warren G; Mitreva, Makedonka

    2015-05-01

    Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in

  13. Effect of the Entomogenous Nematode Nemplectana carpocapsae on the Tachinid Parasite Compsilura concinnata (Diptera: Tachinidae)

    PubMed Central

    Kaya, Harry K.

    1984-01-01

    The entomogenous nematode Neoaplectana carpocapsae and its associated bacterium, Xenorhabdus nematophilus, could not infect the pupal stage of the tachinid Compsilura concinnata through the puparium. N. carpocapsae had an adverse effect on 1-, 2- and 3-day-old C. concinnata larvae within the armyworm host in petri dish tests. All 1-day-old larvae treated with nematodes died in their hosts, whereas 61% and 69% of 2- and 3-day-old larvae treated with nematodes, respectively, died. However, the survivors developed to adults. Nine to thirty-seven percent of adult tachinids which emerged from nematode-treated soil (50 nematodes/cm²) were infected with N. carpocapsae. The nematode adversely affects C. concinnata directly by the frank infection of the tachinid and indirectly by causing the premature death of the host which results in tachinid death. PMID:19295866

  14. Relationships of Plant Parasitic Nematodes to Sites in Native Iowa Prairies

    PubMed Central

    Schmitt, D. P.; Norton, D. C.

    1972-01-01

    Soil samples were collected from three native Iowa prairies and analyzed for plant paiasitic nematodes and selected soil properties. Sites or nematodes were clustered with similarities related to habitat by a cluster analysis of site by nematode species and of nematodes by site. Some nematodes occurred in a wide range of prairie habitats, whereas others were more restricted. For example, greater numbers of Xiphinema americanum were in the low, well-drained sites than in the low wet sites or upland dry sites. Wet sites contained fewer nematodes than well-drained sites. Well-drained sites contained mainly Tylenchorhynchus maximus, Helicotylenchus pseudorobustus, and X. americanum. Wetter sites contained almost exclusively X. chambersi, H. hydrophilus, Telylenchus joctus, and an undescribed species of Tylenchorhynchus. PMID:19319267

  15. Endogenous cellulases in animals: isolation of beta-1, 4-endoglucanase genes from two species of plant-parasitic cyst nematodes.

    PubMed

    Smant, G; Stokkermans, J P; Yan, Y; de Boer, J M; Baum, T J; Wang, X; Hussey, R S; Gommers, F J; Henrissat, B; Davis, E L; Helder, J; Schots, A; Bakker, J

    1998-04-28

    beta-1,4-Endoglucanases (EGases, EC 3.2.1.4) degrade polysaccharides possessing beta-1,4-glucan backbones such as cellulose and xyloglucan and have been found among extremely variegated taxonomic groups. Although many animal species depend on cellulose as their main energy source, most omnivores and herbivores are unable to produce EGases endogenously. So far, all previously identified EGase genes involved in the digestive system of animals originate from symbiotic microorganisms. Here we report on the synthesis of EGases in the esophageal glands of the cyst nematodes Globodera rostochiensis and Heterodera glycines. From each of the nematode species, two cDNAs were characterized and hydrophobic cluster analysis revealed that the four catalytic domains belong to family 5 of the glycosyl hydrolases (EC 3.2.1, 3.2.2, and 3.2.3). These domains show 37-44% overall amino acid identity with EGases from the bacteria Erwinia chrysanthemi, Clostridium acetobutylicum, and Bacillus subtilis. One EGase with a bacterial type of cellulose-binding domain was identified for each nematode species. The leucine-rich hydrophobic core of the signal peptide and the presence of a polyadenylated 3' end precluded the EGases from being of bacterial origin. Cyst nematodes are obligatory plant parasites and the identified EGases presumably facilitate the intracellular migration through plant roots by partial cell wall degradation.

  16. Effects of a parasitic nematode on male mate choice in a livebearing fish with a coercive mating system (western mosquitofish, Gambusia affinis).

    PubMed

    Deaton, Raelynn

    2009-01-01

    I examined the effects of the parasitic larval nematode, Eustrongylides ignotus, on male mate choice in the western mosquitofish, Gambusia affinis. I hypothesized that parasite presence influences male mate choice either directly (via reduction in male mating behavior due to presence of parasite in females) or indirectly (via reduction in male mating behavior due to reduced condition of infected females). Specifically, I tested the predictions that (1) males would mate preferentially with uninfected over infected females (scoring both mating attempts and association time with females); (2) parasitized females would be in poorer condition than non-parasitized females (measured as soluble fat stores); and (3) parasitized females would have reduced fecundity (measured as number of developing embryos). Males preferred to mate with non-parasitized over parasitized females, but showed no differences in association time between females. The nematode did not decrease female body condition, but did decrease female mass, and appeared to decrease female fecundity via reduction in broods (# embryos). Results support that parasites affect male mate choice in mosquitofish; however, the mechanisms used by males to differentiate between parasitized and non-parasitized females remain untested. This study provides the first empirical evidence of parasite affects on male mate choice in livebearing fishes, and suggest a potentially important role for parasite-mediated sexual selection in organisms that use coercive mating as the primary mechanism of obtaining mates.

  17. Gene silencing and sex determination by programmed DNA elimination in parasitic nematodes.

    PubMed

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

    2016-08-01

    Maintenance of genome integrity is essential. However, programmed DNA elimination removes specific DNA sequences from the genome during 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 defines 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

  18. The Carbohydrate-linked Phosphorylcholine of the Parasitic Nematode Product ES-62 Modulates Complement Activation*

    PubMed Central

    Ahmed, Umul Kulthum; Maller, N. Claire; Iqbal, Asif J.; Al-Riyami, Lamyaa; Harnett, William; Raynes, John G.

    2016-01-01

    Parasitic nematodes manufacture various carbohydrate-linked phosphorylcholine (PCh)-containing molecules, including ES-62, a protein with an N-linked glycan terminally substituted with PCh. The PCh component is biologically important because it is required for immunomodulatory effects. We showed that most ES-62 was bound to a single protein, C-reactive protein (CRP), in normal human serum, displaying a calcium-dependent, high-avidity interaction and ability to form large complexes. Unexpectedly, CRP binding to ES-62 failed to efficiently activate complement as far as the C3 convertase stage in comparison with PCh-BSA and PCh-containing Streptococcus pneumoniae cell wall polysaccharide. C1q capture assays demonstrated an ES-62-CRP-C1q interaction in serum. The three ligands all activated C1 and generated C4b to similar extents. However, a C2a active site was not generated following ES-62 binding to CRP, demonstrating that C2 cleavage was far less efficient for ES-62-containing complexes. We proposed that failure of C2 cleavage was due to the flexible nature of carbohydrate-bound PCh and that reduced proximity of the C1 complex was the reason that C2 was poorly cleaved. This was confirmed using synthetic analogues that were similar to ES-62 only in respect of having a flexible PCh. Furthermore, ES-62 was shown to deplete early complement components, such as the rate-limiting C4, following CRP interaction and thereby inhibit classical pathway activation. Thus, flexible PCh-glycan represents a novel mechanism for subversion of complement activation. These data illustrate the importance of the rate-limiting C4/C2 stage of complement activation and reveal a new addition to the repertoire of ES-62 immunomodulatory mechanisms with possible therapeutic applications. PMID:27044740

  19. Adaptation of a nematode parasite to living within the mammalian epithelium.

    PubMed

    Tilney, Lewis G; Connelly, Patricia S; Guild, Gregory M; Vranich, Kelly A; Artis, David

    2005-11-01

    Trichuris muris is a large metazoan pathogen that has been proposed to live intracellularly within living host intestinal epithelial cells. We sought to determine how Trichuris bores its way through the mucosal epithelium and to elucidate the parasite strategies for taking advantage of this intracellular niche. Since the apical surface of the mucosal epithelium is stabilized by the actin cytoskeleton and cell junctions, it remains intact over the worm following its entry into cells. In contrast, non-stabilized lateral membranes of the host epithelial cells are ruptured and cells are killed to form an inert syncytial tunnel. The ventral surface of the nematode worm is studded by pores that overlie bacillary cells; these pores penetrate through the cuticle and are in direct contact with host cytoplasm. From scanning electron micrographs of isolated worms, we calculate that each adult contains approximately 50,000 bacillary cells. The apical surface of the bacillary cells is extensively folded into plicae 40 nm in diameter, thereby increasing the surface area many-fold. Bacillary cells lack organelles for enzyme synthesis and secretion and fail to export protons. However, by confocal light microscopy it was observed that fluorescent macromolecules in excess of 100,000 Da can penetrate into the pores. Taken together, we conclude that the bacillary cells are essential for living inside host epithelium and function predominantly in absorption of soluble molecules from the host mucosal cytoplasm, in essence behaving as an external gut epithelium that is protected from abrasion by the cuticle that surrounds the openings of the bacillary cells. PMID:16217807

  20. Transcriptional and morphological changes in the transition from mycetophagous to phytophagous phase in the plant-parasitic nematode Bursaphelenchus xylophilus.

    PubMed

    Tsai, Isheng J; Tanaka, Ryusei; Kanzaki, Natsumi; Akiba, Mitsuteru; Yokoi, Toshiro; Espada, Margarida; Jones, John T; Kikuchi, Taisei

    2016-01-01

    Drastic physiological and morphological changes in parasites are crucial for the establishment of a successful infection. The nematode Bursaphelenchus xylophilus is the pathogenic agent of pine wilt disease, and little is known about the physiology and morphology in this nematode at the initial stage of infection. In this study, we devised an infection system using pine stem cuttings that allowed us to observe transcriptional and morphological changes in the host-infecting phytophagous phase. We found that 60 genes enriched in xenobiotic detoxification were up-regulated in two independent post-inoculation events, whereas down-regulation was observed in multiple members of collagen gene families. After 48 h of inoculation, the tails in some of the adult females exposed to the host changed in morphology. These results suggest that B. xylophilus may change its physiology and morphology to protect itself and to adapt to the host pine wood environment.

  1. A Proteomic Analysis of the Body Wall, Digestive Tract, and Reproductive Tract of Brugia malayi.

    PubMed

    Morris, C Paul; Bennuru, Sasisekhar; Kropp, Laura E; Zweben, Jesse A; Meng, Zhaojing; Taylor, Rebekah T; Chan, King; Veenstra, Timothy D; Nutman, Thomas B; Mitre, Edward

    2015-01-01

    Filarial worms are parasitic nematodes that cause devastating diseases such as lymphatic filariasis (LF) and onchocerciasis. Filariae are nematodes with complex anatomy including fully developed digestive tracts and reproductive organs. To better understand the basic biology of filarial parasites and to provide insights into drug targets and vaccine design, we conducted a proteomic analysis of different anatomic fractions of Brugia malayi, a causative agent of LF. Approximately 500 adult female B. malayi worms were dissected, and three anatomical fractions (body wall, digestive tract, and reproductive tract) were obtained. Proteins from each anatomical fraction were extracted, desalted, trypsinized, and analyzed by microcapillary reverse-phase liquid chromatography-tandem-mass spectrometry. In total, we identified 4,785 B. malayi proteins. While 1,894 were identified in all three anatomic fractions, 396 were positively identified only within the digestive tract, 114 only within the body wall, and 1,011 only within the reproductive tract. Gene set enrichment analysis revealed a bias for transporters to be present within the digestive tract, suggesting that the intestine of adult filariae is functional and important for nutrient uptake or waste removal. As expected, the body wall exhibited increased frequencies of cytoskeletal proteins, and the reproductive tract had increased frequencies of proteins involved in nuclear regulation and transcription. In assessing for possible vaccine candidates, we focused on proteins sequestered within the digestive tract, as these could possibly represent "hidden antigens" with low risk of prior allergic sensitization. We identified 106 proteins that are enriched in the digestive tract and are predicted to localize to the surface of cells in the the digestive tract. It is possible that some of these proteins are on the luminal surface and may be accessible by antibodies ingested by the worm. A subset of 27 of these proteins appear

  2. Extensive mitochondrial gene rearrangement in a genus of plant parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The nematodes Globodera pallida and G. rostochiensis are two of the only animals known to have multipartite mitochondrial genomes. In such genomes, mitochondrial genes are distributed on multiple circles. The entire sequence of a nematode (Radopholus similis) that belongs to the same superfamily (...

  3. Effects of grafted heirloom tomatoes on parasitic nematode populations in an organic production system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grafting vegetable crops has shown potential to contribute to root-knot nematode management alone and in combination with chemical treatments. In organic production, there are extremely limited options currently available to growers for control of phytoparasitic nematodes. Grafting desirable tomat...

  4. StyletChip: a microfluidic device for recording host invasion behaviour and feeding of plant parasitic nematodes.

    PubMed

    Hu, Chunxiao; Kearn, James; Urwin, Peter; Lilley, Catherine; O' Connor, Vincent; Holden-Dye, Lindy; Morgan, Hywel

    2014-07-21

    Plant parasitic nematodes (PPNs) infest the roots of crops and cause global losses with a severe economic impact on food production. Current chemical control agents are being removed from use due to environmental and toxicity concerns and there is a need for new approaches to crop protection. A key feature of parasitic behaviour for the majority of PPNs is a hollow stomastyle or odontostyle required for interaction with the host plant and feeding. This lance-like microscopic structure, often called a stylet, protrudes from the mouth of the worm and thrusts in a rhythmic manner to stab the host root. Studying stylet activity presents technical challenges and as a consequence the underlying biology is poorly understood. We have addressed this by designing a microfluidic chip which traps the PPN Globodera pallida and permits the recording of an electrophysiological signal concomitant with stylet thrusting. The PDMS chip incorporates a precisely designed aperture to trap the nematode securely around a mid-point of its body. It is fabricated using a novel combination of conventional photolithography and two photon polymerization. The chip incorporates valves for rapid application of test compounds and integral electrodes to facilitate acquisition of electrical signals. We show that stylet thrusting can be induced by controlled application of 5-HT (serotonin) to the worm. Each thrust and retraction produces an electrical waveform that characterises the physiological activity associated with the worm's behaviour. The ability to reproducibly record the stylet activity of PPNs provides a new platform for nematicide screening that specifically focuses on a behaviour that is integral to the parasite host interaction. This is the first report of a microfluidic chip capable of electrophysiological recording from nematodes other than Caenorhabditis elegans. The unique approach is optimised for trapping and recording from smaller worms or worms with distinct anterior body shapes

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

    PubMed Central

    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

  6. The parasitic nematodes Hysterothylacium sp. type MB larvae as bioindicators of lead and cadmium: a comparative study of parasite and host tissues.

    PubMed

    Khaleghzadeh-Ahangar, H; Malek, M; McKenzie, K

    2011-09-01

    Cadmium and lead concentrations were compared in tissues of cutlassfish, Trichiurus lepturus L., its intestinal nematode Hysterothylacium sp. type MB larvae, and in water from the same location in the Sea of Oman. Metal accumulation in hosts, parasites and sea water was measured by ICP-OES. Hysterothylacium larvae from the intestinal lumen and visceral cavity showed much higher metal concentrations than in host tissues or sea water. Statistical analyses revealed no significant differences in metal accumulation between infected and uninfected hosts. Cadmium concentration in the host muscle was lower than in intestine, liver and gonad tissues. The mean concentrations of lead and cadmium in nematodes were 289·03 and 81·5 times higher than in host intestine, 188·4 and 225 times higher than in host muscle, 108·6 and 65·3 times higher than in host gonads, 70·5 and 19·5 times higher than in host liver and 3351 and 148 times higher than in sea water. The results show the value of this and possibly related nematodes as bioindicators of heavy metals and their potential use in environmental studies. PMID:21816122

  7. Heterorhabditis sp. (Nematoda: Heterorhabditidae): A Nematode Parasite Isolated from the Banded Cucumber Beetle Diabrotica balteata.

    PubMed

    Creighton, C S; Fassuliotis, G

    1985-04-01

    A nematode identified as Heterorhabditis sp. was discovered in June 1982 in larval cadavers of the banded cucumber beetle, Diabrotica balteata, in soil on wooded land. Effective beetle control (over 95%) was obtained when larvae were exposed to potted soil containing infective stage nematode juveniles or infected larval cadavers. The nematode was propagated in vivo on larvae of D. balteata, Diaphania nitidalis (the pickleworm), and Galleria mellonella (the greater wax moth). This Heterorhabditis sp. has promising potential as a biocontrol agent for the banded cucumber beetle. PMID:19294074

  8. Heterorhabditis sp. (Nematoda: Heterorhabditidae): A Nematode Parasite Isolated from the Banded Cucumber Beetle Diabrotica balteata

    PubMed Central

    Creighton, C. S.; Fassuliotis, G.

    1985-01-01

    A nematode identified as Heterorhabditis sp. was discovered in June 1982 in larval cadavers of the banded cucumber beetle, Diabrotica balteata, in soil on wooded land. Effective beetle control (over 95%) was obtained when larvae were exposed to potted soil containing infective stage nematode juveniles or infected larval cadavers. The nematode was propagated in vivo on larvae of D. balteata, Diaphania nitidalis (the pickleworm), and Galleria mellonella (the greater wax moth). This Heterorhabditis sp. has promising potential as a biocontrol agent for the banded cucumber beetle. PMID:19294074

  9. Reaction norms of host immunity, host fitness and parasite performance in a mouse--intestinal nematode interaction.

    PubMed

    Lippens, Cédric; Guivier, Emmanuel; Faivre, Bruno; Sorci, Gabriele

    2016-02-01

    The outcome of the encounter between a host and a parasite depends on the synergistic effects of the genetics of the two partners and the environment (sensulato) where the interaction takes place. Reaction norms can depict how host and parasite traits vary across environmental ranges for different genotypes. Here, we performed a large scale experiment where three strains of laboratory mice (SJL, BALB/c and CBA) were infected with four doses of the intestinal nematode Heligmosomoides polygyrus. An increasing infective dose can be considered as a proxy for the environment-dependent risk incontracting the infection. We looked at the fitness traits of hosts and parasites, and assessed the underlying immunological functions likely to affect the observed pattern of resistance/susceptibility/tolerance. We found that the infective dose had a strong effect on both host fitness and parasite performance. Interestingly, for most traits, host genotypes did not rank consistently across the increasing infective doses and according to the expected pattern of strain-specific resistance/susceptibility/tolerance. Analyses of cytokine production allowed better understanding of the mechanistic basis underlying variations in fitness-linked traits. The infective dose affected the shape of the reaction norms of the cytokines IL-4, IL-10 and IL-6. Dose-dependent variation in cytokine production explained, moreover, the strain-specific pattern of infection cost, host resistance and parasite performance. As long as the infective dose increased, there was a marked shift towards a pro-inflammatory status in the SJL strain of mice that was positively correlated with cost of the infection and parasite performance. Overall, our study strongly suggests that the notion of host resistance is labile and depends on the environmental conditions where the interaction takes place. Moreover, integrating information on fitness-linked traits and the underlying mechanisms seems essential for a better

  10. Gastrointestinal nematodes of dairy goats, anthelmintic resistance and practices of parasite control in Northern Italy

    PubMed Central

    2014-01-01

    Background Gastrointestinal nematodes (GINs) are one of the main constraints to ruminant production worldwide. Anthelmintic resistance (AR) has been reported in goats throughout Europe, yet little is known about the AR status in Italy. The aims of the study were: i) determine the frequency of AR in GINs in goat flocks in Northern Italy, Italy, ii) survey goat farmers on the current practices of parasite control, iii) update the species composition of the gastrointestinal helminthofauna. Thirty three flocks were enrolled and 1288 individual fecal samples were collected. Based on the egg per gram (EPG), 15 flocks were selected to evaluate the presence of AR in GINs with the Fecal Egg Count Reduction Test (FECRT). A questionnaire surveyed 110 dairy goat farmers to acquire information about farm management and drenching practices against GINs. Further, the gastrointestinal tracts of 42 goats were analyzed. Results The FECRs indicated that five of the 15 flocks had problems of AR, which was identified in all two of the anthelmintic classes tested. Resistance and suspected resistance was found in 40% of the flocks selected for AR testing that were treated with benzimidazoles while 20% of the flocks treated with eprinomectin had resistant GINs. Teladorsagia/Trichostrongylus L3 were isolated from the post-treatment coprocultures of all flocks with resistance but not from the flock with suspected oxfendazole resistance. Treatments against helminths were performed once annually in 73.63% of the flocks, but 20.00% of farmers declared not regularly treating their goats every year. Annual treatments usually occurred in autumn or winter at dose rate for sheep. Te. circumcincta, H. contortus, Tr. colubriformis, Skrjabinema caprae and Oesophagostomum venulosum were the most abundant and prevalent species of the gastrointestinal tract. Conclusions Strategies to prevent the development of AR should be widely adopted in Northern Italy. Further, farmers and practitioners should be

  11. Nematicidal activity of 5-hydroxymethyl-2-furoic acid against plant-parasitic nematodes.

    PubMed

    Kimura, Yasuo; Tani, Satoko; Hayashi, Asami; Ohtani, Kouhei; Fujioka, Shozo; Kawano, Tsuyoshi; Shimada, Atsumi

    2007-01-01

    A nematicide, 5-hydroxymethyl-2-furoic acid (1), was isolated from cultures of the fungus Aspergillus sp. and its structure was identified by spectroscopic analysis. Compound 1 showed effective nematicidal activities against the pine wood nematode Bursaphelenchus xylophilus and the free-living nematode Caenorhabditis elegans without inhibitory activity against plant growth, but 1 did not show any effective nematicidal activity against Pratylenchus penetrans. PMID:17542490

  12. Species discovery and diversity in Lobocriconema (Criconematidae: Nematoda) and related plant-parasitic nematodes from North American ecoregions.

    PubMed

    Powers, T O; Bernard, E C; Harris, T; Higgins, R; Olson, M; Olson, S; Lodema, M; Matczyszyn, J; Mullin, P; Sutton, L; Powers, K S

    2016-03-03

    deciduous forest, but definitive glacial refugia for this group of plant parasitic nematodes have yet to be identified. Unlike agricultural pest species of plant-parasitic nematodes, there is little evidence of long-distance dispersal in Lobocriconema as revealed by haplotype distribution. Most haplotype groups were characterized by low levels of intragroup genetic variation and large genetic distances between haplotype groups. The localization of nematode haplotypes together with their characteristic plant communities could provide insight into the historical formation of these belowground biotic communities.

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

    PubMed Central

    Duan, Mingyue; Xiong, Jinfeng; Lu, Dandan; Wang, Guoxiu; Ai, Hui

    2016-01-01

    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 and functional

  14. Species discovery and diversity in Lobocriconema (Criconematidae: Nematoda) and related plant-parasitic nematodes from North American ecoregions.

    PubMed

    Powers, T O; Bernard, E C; Harris, T; Higgins, R; Olson, M; Olson, S; Lodema, M; Matczyszyn, J; Mullin, P; Sutton, L; Powers, K S

    2016-01-01

    deciduous forest, but definitive glacial refugia for this group of plant parasitic nematodes have yet to be identified. Unlike agricultural pest species of plant-parasitic nematodes, there is little evidence of long-distance dispersal in Lobocriconema as revealed by haplotype distribution. Most haplotype groups were characterized by low levels of intragroup genetic variation and large genetic distances between haplotype groups. The localization of nematode haplotypes together with their characteristic plant communities could provide insight into the historical formation of these belowground biotic communities. PMID:27394307

  15. An Aphelenchoides sp. nematode Parasitic of Polianthes tuberosa in the Mekong Delta

    PubMed Central

    Thi Thu Cuc, Nguyen; Pilon, Marc

    2007-01-01

    Polianthes tuberosa is a commercially valuable flower crop in the Mekong Delta of Vietnam that is propagated by the harvesting and planting of bulbs. The cultivation of P. tuberosa is complicated by an endemic nematode infection that damages a high proportion of the plants. Based on morphological criteria and ribosomal RNA gene sequencing, we have determined that the infection is caused by an Aphelenchoides sp. nematode and is most likely Aphelenchoides besseyi. By scoring various parts of harvested plants with flowers for the presence of viable nematodes over a period of six months, we determined that the nematode is an ectoparasite that can survive the intercrop periods, especially in the bulbs that are used to plant new crops. A comparison of farming practices in the Mekong Delta failed to identify useful control methods, but rather indicated that fields that have cultivated P. tuberosa for the longest periods suffer the worst damage from the nematode infection. Finally, we demonstrated that the nematode is capable of infecting 30 rice cultivars but does not cause the white tip disease usually associated with A. besseyi infection. PMID:19259495

  16. Effects of Potato-Cotton Cropping Systems and Nematicides on Plant-Parasitic Nematodes and Crop Yields

    PubMed Central

    Crow, W. T.; Weingartner, D. P.; Dickson, D. W.

    2000-01-01

    Belonolaimus longicaudatus has been reported as damaging both potato (Solanum tuberosum) and cotton (Gossypium hirsutum). These crops are not normally grown in cropping systems together in areas where the soil is infested with B. longicaudatus. During the 1990s cotton was grown in a potato production region that was a suitable habitat for B. longicaudatus. It was not known how integrating the production of these two crops by rotation or double-cropping would affect the population densities of B. longicaudatus, other plant-parasitic nematodes common in the region, or crop yields. A 3-year field study evaluated the viability of both crops in monocropping, rotation, and double-cropping systems. Viability was evaluated using effects on population densities of plant-parasitic nematodes and yields. Rotation of cotton with potato was found to decrease population densities of B. longicaudatus and Meloidogyne incognita in comparison with continuous potato. Population densities of B. longicaudatus following double-cropping were greater than following continuous cotton. Yields of both potato and cotton in rotation were equivalent to either crop in monocropping. Yields of both crops were lower following double-cropping when nematicides were not used. PMID:19270980

  17. Host cues induce egg hatching and pre-parasitic foraging behaviour in the mosquito parasitic nematode, Strelkovimermis spiculatus.

    PubMed

    Wang, Yi; Lutfi, Zainal; Dong, Limin; Suman, Devi S; Sanad, Manar; Gaugler, Randy

    2012-09-01

    The responses of eggs in diapause and the infective stage of the nematode, Strelkovimermis spiculatus, to larvae of its host, Culex pipiens pipiens, were investigated in the laboratory. The results indicated that the presence of the host induced the egg hatching. The hatching rate increased when larger numbers of host larvae were present. Second instar mosquito larvae induced significantly higher hatching rates than any other stages. These findings explain how S. spiculatus synchronizes its life cycle with its host life cycle and population dynamics to increase its fitness when the natural habitat is constantly covered by water. Direct exposure of the nematode eggs to host larvae resulted in consumption of as many as 20 eggs per host. The eggs consumed caused 0-70% host mortality depending on the number consumed, which indicated an infection path other than cuticle penetration although it may represent a rare situation in nature. The result of host cue assays showed that the combination of chemical cues and physical vibration induced the highest egg hatching, which may increase the chance of host availability after hatching. However, once hatched, the nematodes ignored vibrations and used only chemical cues for host location. These findings suggest that eggs hatch synchronously with the most susceptible mosquito stage and with peak mosquito larval density.

  18. Cystatins from filarial parasites: evolution, adaptation and function in the host-parasite relationship.

    PubMed

    Gregory, William F; Maizels, Rick M

    2008-01-01

    Cystatins, together with stefins and kininogens, are members of the cystatin superfamily of cysteine protease inhibitors (CPI) present across the animal and plant kingdoms. Their role in parasitic organisms may encompass both essential developmental processes and specific interactions with the parasite's vector and/or final host. We summarise information gathered on three cystatins from the human filarial nematode Brugia malayi (Bm-CPI-1, -2 and -3), and contrast them those expressed by other parasites and by the free-living nematode Caenorhabditis elegans. Bm-CPI-2 differs from C. elegans cystatin, having acquired the additional function of inhibiting asparaginyl endopeptidase (AEP), in a manner similar to some human cystatins. Thus, we propose that Bm-CPI-2 and orthologues from related filarial parasites represent a new subset of nematode cystatins. Bm-CPI-1 and CPI-3 share only 25% amino acid identity with Bm-CPI-2, and lack an evolutionarily conserved glycine residue in the N-terminal region. These sequences group distantly from the other nematode cystatins, and represent a second novel subset of filarial cystatin-like genes. Expression analyses also show important differences between the CPI-2 and CPI-1/-3 groups. Bm-cpi-2 is expressed at all time points of the parasite life cycle, while Bm-cpi-1 and -3 expression is confined to the late stages of development in the mosquito vector, terminating within 48h of infection of the mammalian host. Hence, we hypothesise that CPI-2 has evolved to block mammalian proteases (including the antigen-processing enzyme AEP) while CPI-1 and -3 function in the milieu of the mosquito vector necessary for transmission of the parasite. PMID:18249028

  19. Sensory Neuroanatomy of Parastrongyloides trichosuri, a Nematode Parasite of Mammals: Amphidial Neurons of the First-Stage Larva

    PubMed Central

    Zhu, He; Li, Jian; Nolan, Thomas J.; Schad, Gerhard A.; Lok, James B.

    2011-01-01

    Owing to its ability to switch between free-living and parasitic modes of development, Parastrongyloides trichosuri represents a valuable model with which to study the evolution of parasitism among the nematodes, especially aspects pertaining to morphogenesis of infective third-stage larvae. In the free-living nematode Caenorhabditis elegans, developmental fates of third-stage larvae are determined in part by environmental cues received by chemosensory neurons in the amphidial sensillae. As a basis for comparative study, we have described the neuroanatomy of the amphidial sensillae of P. trichosuri. Using computational methods we incorporated serial electron micrographs into a three-dimensional reconstruction of the amphidial neurons of this parasite. Each amphid is innervated by 13 neurons, and the dendritic processes of 10 of these extend nearly to the amphidial pore. Dendritic processes of two specialized neurons leave the amphidial channel and terminate within invaginations of the sheath cell. One of these is similar to the finger cell of C. elegans, terminating in digitiform projections. The other projects a single cilium into the sheath cell. The dendritic process of a third specialized neuron terminates within the tight junction of the amphid. Each amphidial neuron was traced from the tip of its dendrite(s) to its cell body in the lateral ganglion. Positions of these cell bodies approximate those of morphologically similar amphidial neurons in Caenorhabditis elegans, so the standard nomenclature for amphidial neurons in C. elegans was adopted. A map of cell bodies within the lateral ganglion of P. trichosuri was prepared to facilitate functional study of these neurons. PMID:21456026

  20. Management of Plant-parasitic Nematodes on Peanut with Selected Nematicides in North Carolina

    PubMed Central

    Koenning, S. R.; Bailey, J. E.; Schmitt, D. P.; Barker, K. R.

    1998-01-01

    Field experiments were conducted to determine peanut growth and yield responses to selected fumigant and nonfumigant nemaficide treatments in 1988 and 1989. All treatments with the fumigant 1, 3-D significantly suppressed nematode reproduction (Meloidogyne arenaria, M. hapla, and Mesocriconema ornatum) and enhanced peanut yields over the other treatments in four tests in 1988. Yield increases with the fumigant ranged from about 20% to 100% over the untreated control. Test sites in 1989 had lower nematode levels than those for 1988, and fewer positive plant and nematode responses were detected. Treatments with 1,3-D improved peanut quality but not yield in one experiment with low levels of M. hapla and M. ornatum in 1988. The 1,3-D + chloropicrin treatments at another site gave higher peanut yields than 1,3-D alone. PMID:19274260

  1. Quantitative digital imaging of banana growth suppression by plant parasitic nematodes.

    PubMed

    Roderick, Hugh; Mbiru, Elvis; Coyne, Danny; Tripathi, Leena; Atkinson, Howard J

    2012-01-01

    A digital camera fitted with a hemispherical lens was used to generate canopy leaf area index (LAI) values for a banana (Musa spp.) field trial with the aim of establishing a method for monitoring stresses on tall crop plants. The trial in Uganda consisted of two cultivars susceptible to nematodes, a plantain, Gonja manjaya and an East African Highland banana, Mbwazirume, plus a nematode resistant dessert banana, Yangambi km5. A comparative approach included adding a mixed population of Radopholus similis, Helicotylenchus multicinctus and Meloidogyne spp. to the soil around half the plants of each cultivar prior to field planting. Measurements of LAI were made fortnightly from 106 days post-planting over two successive cropping cycles. The highest mean LAI during the first cycle for Gonja manjaya was suppressed to 74.8±3.5% by the addition of nematodes, while for Mbwazirume the values were reduced to 71.1±1.9%. During the second cycle these values were 69.2±2.2% and 72.2±2.7%, respectively. Reductions in LAI values were validated as due to the biotic stress by assessing nematode numbers in roots and the necrosis they caused at each of two harvests and the relationship is described. Yield losses, including a component due to toppled plants, were 35.3% and 55.3% for Gonja manjaya and 31.4% and 55.8% for Mbwazirume, at first and second harvests respectively. Yangambi km5 showed no decrease in LAI and yield in the presence of nematodes at both harvests. LAI estimated by hemispherical photography provided a rapid basis for detecting biotic growth checks by nematodes on bananas, and demonstrated the potential of the approach for studies of growth checks to other tall crop plants caused by biotic or abiotic stresses. PMID:23285286

  2. Quantitative digital imaging of banana growth suppression by plant parasitic nematodes.

    PubMed

    Roderick, Hugh; Mbiru, Elvis; Coyne, Danny; Tripathi, Leena; Atkinson, Howard J

    2012-01-01

    A digital camera fitted with a hemispherical lens was used to generate canopy leaf area index (LAI) values for a banana (Musa spp.) field trial with the aim of establishing a method for monitoring stresses on tall crop plants. The trial in Uganda consisted of two cultivars susceptible to nematodes, a plantain, Gonja manjaya and an East African Highland banana, Mbwazirume, plus a nematode resistant dessert banana, Yangambi km5. A comparative approach included adding a mixed population of Radopholus similis, Helicotylenchus multicinctus and Meloidogyne spp. to the soil around half the plants of each cultivar prior to field planting. Measurements of LAI were made fortnightly from 106 days post-planting over two successive cropping cycles. The highest mean LAI during the first cycle for Gonja manjaya was suppressed to 74.8±3.5% by the addition of nematodes, while for Mbwazirume the values were reduced to 71.1±1.9%. During the second cycle these values were 69.2±2.2% and 72.2±2.7%, respectively. Reductions in LAI values were validated as due to the biotic stress by assessing nematode numbers in roots and the necrosis they caused at each of two harvests and the relationship is described. Yield losses, including a component due to toppled plants, were 35.3% and 55.3% for Gonja manjaya and 31.4% and 55.8% for Mbwazirume, at first and second harvests respectively. Yangambi km5 showed no decrease in LAI and yield in the presence of nematodes at both harvests. LAI estimated by hemispherical photography provided a rapid basis for detecting biotic growth checks by nematodes on bananas, and demonstrated the potential of the approach for studies of growth checks to other tall crop plants caused by biotic or abiotic stresses.

  3. Molecular and biochemical characterization of nematode cofactor independent phosphoglycerate mutases.

    PubMed

    Raverdy, Sylvine; Zhang, Yinhua; Foster, Jeremy; Carlow, Clotilde K S

    2007-12-01

    Phosphoglycerate mutase (PGM, EC 5.4.2.1) catalyzes the isomerization of 3-phosphoglycerate and 2-phosphoglycerate in glycolysis and gluconeogenesis. Two distinct types of PGM exist in nature, one that requires 2,3-bisphosphoglycerate as a cofactor (dPGM) and another that does not (iPGM). The two enzymes are structurally distinct and possess different mechanisms of action. In any particular organism, one form may exist or both. Nematodes possess the iPGM form whereas mammals have dPGM. In the present study, we have cloned and expressed iPGM from Onchocerca volvulus and described the catalytic properties of O. volvulus, Brugia malayi and Caenorhabditis elegans iPGM enzymes. Temperature and pH optima were determined for each enzyme. Like other iPGM enzymes, the activities of the nematode iPGM enzymes were dependent on the presence of divalent ions. Inactivation by EDTA could be restored most effectively by magnesium and manganese ions. Kinetic parameters and specific activities of the various recombinant enzymes were determined. The high similarity in catalytic properties among the enzymes indicates that a single enzyme inhibitor would likely be effective against all nematode enzymes. Inhibition of iPGM activity in vivo may lead to lethality as indicated by RNAi studies in C. elegans. Our results support the development of iPGM as a promising drug target in parasitic nematodes.

  4. PHYLOGEOGRAPHY OF A HOLARCTIC NEMATODE: SOBOLIPHYME BATURINI AMONG MUSTELIDS: CLIMATE CHANGE, EPISODIC COLONIZATION AND DIVERSIFICATION IN A COMPLEX HOST-PARASITE SYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Phylogeography of Soboliphyme baturini, a nematode parasite in mustelids, is explored across Beringia. Sequences of the mitochondrial cytochrome c oxidase subunit 1 (COI) and nicotinamide adenine dinucleotide dehydrogenase subunit 4 (ND4) genes were evaluated from 38 individuals representing 19 lo...

  5. An In Vitro/In Vivo Model to Analyze the Effects of Flubendazole Exposure on Adult Female Brugia malayi.

    PubMed

    O'Neill, Maeghan; Mansour, Abdelmoneim; DiCosty, Utami; Geary, James; Dzimianski, Michael; McCall, Scott D; McCall, John W; Mackenzie, Charles D; Geary, Timothy G

    2016-05-01

    Current control strategies for onchocerciasis and lymphatic filariasis (LF) rely on prolonged yearly or twice-yearly mass administration of microfilaricidal drugs. Prospects for near-term elimination or eradication of these diseases would be improved by availability of a macrofilaricide that is highly effective in a short regimen. Flubendazole (FLBZ), a benzimidazole anthelmintic registered for control of human gastrointestinal nematode infections, is a potential candidate for this role. FLBZ has profound and potent macrofilaricidal effects in many experimental animal models of filariases and in one human trial for onchocerciasis after parental administration. Unfortunately, the marketed formulation of FLBZ provides very limited oral bioavailability and parenteral administration is required for macrofilaricidal efficacy. A new formulation that provided sufficient oral bioavailability could advance FLBZ as an effective treatment for onchocerciasis and LF. Short-term in vitro culture experiments in adult filariae have shown that FLBZ damages tissues required for reproduction and survival at pharmacologically relevant concentrations. The current study characterized the long-term effects of FLBZ on adult Brugia malayi by maintaining parasites in jirds for up to eight weeks following brief drug exposure (6-24 hr) to pharmacologically relevant concentrations (100 nM-10 μM) in culture. Morphological damage following exposure to FLBZ was observed prominently in developing embryos and was accompanied by a decrease in microfilarial output at 4 weeks post-exposure. Although FLBZ exposure clearly damaged the parasites, exposed worms recovered and were viable 8 weeks after treatment. PMID:27145083

  6. An In Vitro/In Vivo Model to Analyze the Effects of Flubendazole Exposure on Adult Female Brugia malayi

    PubMed Central

    O’Neill, Maeghan; Mansour, Abdelmoneim; DiCosty, Utami; Geary, James; Dzimianski, Michael; McCall, Scott D.; McCall, John W.; Mackenzie, Charles D.; Geary, Timothy G.

    2016-01-01

    Current control strategies for onchocerciasis and lymphatic filariasis (LF) rely on prolonged yearly or twice-yearly mass administration of microfilaricidal drugs. Prospects for near-term elimination or eradication of these diseases would be improved by availability of a macrofilaricide that is highly effective in a short regimen. Flubendazole (FLBZ), a benzimidazole anthelmintic registered for control of human gastrointestinal nematode infections, is a potential candidate for this role. FLBZ has profound and potent macrofilaricidal effects in many experimental animal models of filariases and in one human trial for onchocerciasis after parental administration. Unfortunately, the marketed formulation of FLBZ provides very limited oral bioavailability and parenteral administration is required for macrofilaricidal efficacy. A new formulation that provided sufficient oral bioavailability could advance FLBZ as an effective treatment for onchocerciasis and LF. Short-term in vitro culture experiments in adult filariae have shown that FLBZ damages tissues required for reproduction and survival at pharmacologically relevant concentrations. The current study characterized the long-term effects of FLBZ on adult Brugia malayi by maintaining parasites in jirds for up to eight weeks following brief drug exposure (6–24 hr) to pharmacologically relevant concentrations (100 nM—10 μM) in culture. Morphological damage following exposure to FLBZ was observed prominently in developing embryos and was accompanied by a decrease in microfilarial output at 4 weeks post-exposure. Although FLBZ exposure clearly damaged the parasites, exposed worms recovered and were viable 8 weeks after treatment. PMID:27145083

  7. Inter and intra-specific diversity of parasites that cause lymphatic filariasis

    PubMed Central

    McNulty, Samantha N.; Mitreva, Makedonka; Weil, Gary J.; Fischer, Peter U.

    2013-01-01

    Lymphatic filariasis is caused by three closely related nematode parasites: Wuchereria bancrofti, Brugia malayi and Brugia timori. These species have many ecological variants that differ in several aspects of their biology such as mosquito vector species, host range, periodicity, and morphology. Although the genome of B. malayi (the first genome sequenced from a parasitic nematode) has been available for more than five years, very little is known about genetic variability among the lymphatic dwelling filariae. The genetic diversity among these worms is not only interesting from a biological perspective, but it may have important practical implications for the Global Program to Eliminate Lymphatic Filariasis, as the parasites may respond differently to diagnostic tests and/or medical interventions. Therefore, better information on their genetic variability is urgently needed. With improved methods for nucleic acid extraction and recent advances in sequencing chemistry and instrumentation, this gap can be filled relatively inexpensively. Improved information on filarial genetic diversity may increase the chances of success for lymphatic filariasis elimination programs. PMID:23201850

  8. 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.

    PubMed

    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.

  9. Cardio-Pulmonary Parasitic Nematodes Affecting Cats in Europe: Unraveling the Past, Depicting the Present, and Predicting the Future

    PubMed Central

    Traversa, Donato; Di Cesare, Angela

    2014-01-01

    Various cardio-pulmonary parasitic nematodes infecting cats have recently been fascinating and stimulating the attention of the Academia, pharmaceutical companies, and veterinary practitioners. This is the case of the metastrongyloids: Aelurostrongylus abstrusus and Troglostrongylus brevior, the trichuroid: Capillaria aerophila (syn. Eucoleus aerophilus), and the filarioid: Dirofilaria immitis. Apparently, these parasites have been emerging in several European countries, thus, gaining an important role in feline parasitology and clinical practice. Under a practical standpoint, a sound knowledge of the biological, epidemiological, and clinical impact of cardio-respiratory parasitoses affecting cats, in addition to a potential risk of introduction, establishment, and spreading of “new” parasites in Europe is mandatory in order to understand the present and future impact for feline medicine and to address new strategies of control and treatment. The purpose of the present article is to review the current knowledge of heartworm and lungworm infections in cats, discussing and comparing past and present issues, and predicting possible future scenarios. PMID:26664917

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

    PubMed

    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. PMID:8774767

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Identification of Peptide Mimics of a Glycan Epitope on the Surface of Parasitic Nematode Larvae.

    PubMed

    Umair, Saleh; Deng, Qing; Roberts, Joanna M; Shaw, Richard J; Sutherland, Ian A; Pernthaner, Anton

    2016-01-01

    Phage display was used to identify peptide mimics of an immunologically protective nematode glycan (CarLA) by screening a constrained C7C peptide library for ligands that bound to an anti-CarLA mAb (PAB1). Characterisation of these peptide mimotopes revealed functional similarities with an epitope that is defined by PAB1. Mimotope vaccinations of mice with three selected individual phage clones facilitated the induction of antibody responses that recognised the purified, native CarLA molecule which was obtained from Trichostrongylus colubriformis. Furthermore, these mimotopes are specifically recognised by antibodies in the saliva of animals that were immune to natural polygeneric nematode challenge. This shows that antibodies to the PAB1 epitope form part of the mucosal polyclonal anti-CarLA antibody response of nematode immune host animals. This demonstrates that the selected peptide mimotopes are of biological relevance. These peptides are the first to mimic the PAB1 epitope of CarLA, a defined larval glycan epitope which is conserved between many nematode species. PMID:27579674

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

    PubMed

    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. Management of Plant-parasitic Nematodes with a Chitin-Urea Soil Amendment and Other Materials

    PubMed Central

    Westerdahl, B. B.; Carlson, H. L.; Grant, J.; Radewald, J. D.; Welch, N.; Anderson, C. A.; Darso, J.; Kirby, D.; Shibuya, F.

    1992-01-01

    Field trials were conducted with a chitin-urea soil amendment and several other nematicides on four crop-nematode combinations: tomato-Meloidogyne incognita; potato-Meloidogyne chitwoodi; walnut-Pratylenchus vulnus; and brussels sprouts-Heterodera schachtii. Significant (P ≤ 0.10) nematode population reductions were obtained with the chitin-urea soil amendment in the trims on potato and walnut. In the trials on brussels sprouts and on tomato, phytotoxicity occurred at rates of 1,868 and 1,093 kg/ha, respectively. Significant (P ≤ 0.10) nematode reductions were also obtained with metham sodium on potato; with 1,3-D on tomato and brussels sprouts; and with sodium tetrathiocarbonate, XRM 5053, fenamiphos, ethoprop, LX1075-05, LX1075-07, and SN 109106 on tomato. The following materials did not provide significant nematode control under the conditions of the particular experiments: metham sodium, oxamyl, and Yucca extract on tomato; and dazomet granules on brussels sprouts. PMID:19283044

  15. Management of Plant-parasitic Nematodes with a Chitin-Urea Soil Amendment and Other Materials.

    PubMed

    Westerdahl, B B; Carlson, H L; Grant, J; Radewald, J D; Welch, N; Anderson, C A; Darso, J; Kirby, D; Shibuya, F

    1992-12-01

    Field trials were conducted with a chitin-urea soil amendment and several other nematicides on four crop-nematode combinations: tomato-Meloidogyne incognita; potato-Meloidogyne chitwoodi; walnut-Pratylenchus vulnus; and brussels sprouts-Heterodera schachtii. Significant (P nematode population reductions were obtained with the chitin-urea soil amendment in the trims on potato and walnut. In the trials on brussels sprouts and on tomato, phytotoxicity occurred at rates of 1,868 and 1,093 kg/ha, respectively. Significant (P nematode reductions were also obtained with metham sodium on potato; with 1,3-D on tomato and brussels sprouts; and with sodium tetrathiocarbonate, XRM 5053, fenamiphos, ethoprop, LX1075-05, LX1075-07, and SN 109106 on tomato. The following materials did not provide significant nematode control under the conditions of the particular experiments: metham sodium, oxamyl, and Yucca extract on tomato; and dazomet granules on brussels sprouts. PMID:19283044

  16. Identification of Peptide Mimics of a Glycan Epitope on the Surface of Parasitic Nematode Larvae

    PubMed Central

    Roberts, Joanna M.; Shaw, Richard J.; Sutherland, Ian A.; Pernthaner, Anton

    2016-01-01

    Phage display was used to identify peptide mimics of an immunologically protective nematode glycan (CarLA) by screening a constrained C7C peptide library for ligands that bound to an anti-CarLA mAb (PAB1). Characterisation of these peptide mimotopes revealed functional similarities with an epitope that is defined by PAB1. Mimotope vaccinations of mice with three selected individual phage clones facilitated the induction of antibody responses that recognised the purified, native CarLA molecule which was obtained from Trichostrongylus colubriformis. Furthermore, these mimotopes are specifically recognised by antibodies in the saliva of animals that were immune to natural polygeneric nematode challenge. This shows that antibodies to the PAB1 epitope form part of the mucosal polyclonal anti-CarLA antibody response of nematode immune host animals. This demonstrates that the selected peptide mimotopes are of biological relevance. These peptides are the first to mimic the PAB1 epitope of CarLA, a defined larval glycan epitope which is conserved between many nematode species. PMID:27579674

  17. Effect of Sorghum-Sudangrass and Velvetbean Cover Crops on Plant-Parasitic Nematodes Associated with Potato Production in Florida

    PubMed Central

    Crow, W. T.; Weingartner, D. P.; Dickson, D. W.; McSorley, R.

    2001-01-01

    In a 3-year field study, population densities of Belonolaimus longicaudatus and other plant-parasitic nematodes and crop yields were compared between potato (Solanum tuberosum) cropping systems where either sorghum-sudangrass (Sorghum bicolor × S. arundinaceum) or velvetbean (Mucuna pruriens) was grown as a summer cover crop. Population densities of B. longicaudatus, Paratrichodorus minor, Tylenchorhynchus sp., and Mesocriconema sp. increased on sorghum-sudangrass. Population densities of P. minor and Mesocriconema sp. increased on velvetbean. Sorghum-sudangrass increased population densities of B. longicaudatus and Mesocriconema sp. on a subsequent potato crop compared to velvetbean. Potato yields following velvetbean were not greater than following sorghum-sudangrass despite reductions in population densities of B. longicaudatus. PMID:19265888

  18. Efficiency of feeding Duddingtonia flagrans chlamydospores to control nematode parasites of first-season grazing goats in France.

    PubMed

    Paraud, C; Pors, I; Chartier, C

    2007-04-01

    A field trial, conducted over two consecutive years, was aimed at assessing the efficacy of the administration of spores of the nematophagous fungus Duddingtonia flagrans to young goats for the control of nematode parasite infections on a French commercial dairy goat flock. For both years, the first-year grazing kids were divided into two similarly managed groups (fungus and control groups): in 2003 a daily dose rate of 5 x 10(5) spores/kg body weight was given to the fungus-group animals, while in 2004 a daily dose rate of 10(6) spores/kg body weight was used; the other half of the kids, acting as control, did not receive the spores. Parameters measured every 3 weeks included nematode egg excretion, larval development in faecal cultures and pasture larval counts. Additionally, at the beginning, the middle and the end of each grazing season, the goats were weighed and blood samples for pepsinogen determination were collected. In 2003, similar results were recorded for all the measured parameters in the control and fungus groups. In contrast, in 2004, the kids receiving the spores showed lower faecal egg counts and pepsinogen levels at the end of the season and higher growth rate compared to kids of the control group.

  19. Bafilolides, potent inhibitors of the motility and development of the free-living stages of parasitic nematodes.

    PubMed

    Lacey, E; Gill, J H; Power, M L; Rickards, R W; O'Shea, M G; Rothschild, J M

    1995-03-01

    Three Streptomyces isolates were identified as producing macrolide antibiotics of the bafilomycin or leucanicidin types during an evaluation of Australian actinomyces for the production of inhibitors of larval development in the parasitic nematode, Haemonchus contortus. Bafilomycins A1, B1, C1, and D were obtained from culture A239 and the 2-O-methyl-L-rhamnosyl derivative of bafilomycin A1, leucanicidin, from cultures A223 and A240. All these 'bafilolides' gave similar patterns of inhibition typified by an initial paralysis of newly hatched L1 larvae and a lethal toxicity within 24 h. LD50 values for inhibition of larval development of McMaster H. contortus ranged from 0.23 micrograms ml-1 for leucanicidin to 2.5 micrograms ml-1 for bafilomycin D. The bafilolides had broad spectrum nematocidal activity, being equi-potent as inhibitors of H. contortus, Trichostrongylus colubriformis and Ostertagia circumcincta larval development. Further, all bafilolides caused some inhibition of H. contortus L3 motility, with the semi-synthetic analogue, bafilomycin B2, the most potent inhibitor (LP50 against McMaster H. contortus 1.9 microgram ml-1). Nematode strains resistant to the known benzimidazole, levamisole and avermectin anthelmintics showed no cross resistance to the bafilolides, supporting the hypothesis that the bafilolides act by an independent mechanism.

  20. The effect of opiates and opiate antagonists on heat latency response in the parasitic nematode Ascaris suum.

    PubMed

    Pryor, Stephen C; Nieto, Fernando; Henry, Sherwyn; Sarfo, Jennifer

    2007-04-10

    The effects of the opiates morphine and morphine-6-glucuronide (M6G), the mu opioid receptor specific antagonist D-Phe-Cys-Tyr-D-Trp-Om-Thr-Pen-Thr-NH(2) (CTOP), and the general opiate antagonist naloxone on the latency of response to thermal stimulation were determined in the parasitic nematode Ascaris suum. Thermal detection and avoidance behaviors of the worms were evaluated with a tail flick analgesia meter using a modification of a technique employed for nociception experiments in rodents. Morphine and M6G were shown to have a dose dependent analgesic effect on A. suum's latency of response to heat with morphine being the most potent. The analgesic effect of morphine was reversed by naloxone but not CTOP. Neither naloxone nor CTOP was able to block the analgesia of M6G. CTOP but not naloxone had significant analgesic effects on its own. These findings are generally consistent with previous results on the effects of opiates and nitric oxide release from A. suum tissue. Apparently these nematodes possess opioid receptors that effect nociception.

  1. Secretome Analysis of the Pine Wood Nematode Bursaphelenchus xylophilus Reveals the Tangled Roots of Parasitism and Its Potential for Molecular Mimicry

    PubMed Central

    Shinya, Ryoji; Takeuchi, Yuko; Ueda, Mitsuyoshi; Futai, Kazuyoshi

    2013-01-01

    Since it was first introduced into Asia from North America in the early 20th century, the pine wood nematode Bursaphelenchus xylophilus has caused the devastating forest disease called pine wilt. The emerging pathogen spread to parts of Europe and has since been found as the causal agent of pine wilt disease in Portugal and Spain. In 2011, the entire genome sequence of B. xylophilus was determined, and it allowed us to perform a more detailed analysis of B. xylophilus parasitism. Here, we identified 1,515 proteins secreted by B. xylophilus using a highly sensitive proteomics method combined with the available genomic sequence. The catalogue of secreted proteins contained proteins involved in nutrient uptake, migration, and evasion from host defenses. A comparative functional analysis of the secretome profiles among parasitic nematodes revealed a marked expansion of secreted peptidases and peptidase inhibitors in B. xylophilus via gene duplication and horizontal gene transfer from fungi and bacteria. Furthermore, we showed that B. xylophilus secreted the potential host mimicry proteins that closely resemble the host pine’s proteins. These proteins could have been acquired by host–parasite co-evolution and might mimic the host defense systems in susceptible pine trees during infection. This study contributes to an understanding of their unique parasitism and its tangled roots, and provides new perspectives on the evolution of plant parasitism among nematodes. PMID:23805310

  2. Structure of the Trehalose-6-phosphate Phosphatase from Brugia malayi Reveals Key Design Principles for Anthelmintic Drugs

    PubMed Central

    Farelli, Jeremiah D.; Galvin, Brendan D.; Li, Zhiru; Liu, Chunliang; Aono, Miyuki; Garland, Megan; Hallett, Olivia E.; Causey, Thomas B.; Ali-Reynolds, Alana; Saltzberg, Daniel J.; Carlow, Clotilde K. S.; Dunaway-Mariano, Debra; Allen, Karen N.

    2014-01-01

    Parasitic nematodes are responsible for devastating illnesses that plague many of the world's poorest populations indigenous to the tropical areas of developing nations. Among these diseases is lymphatic filariasis, a major cause of permanent and long-term disability. Proteins essential to nematodes that do not have mammalian counterparts represent targets for therapeutic inhibitor discovery. One promising target is trehalose-6-phosphate phosphatase (T6PP) from Brugia malayi. In the model nematode Caenorhabditis elegans, T6PP is essential for survival due to the toxic effect(s) of the accumulation of trehalose 6-phosphate. T6PP has also been shown to be essential in Mycobacterium tuberculosis. We determined the X-ray crystal structure of T6PP from B. malayi. The protein structure revealed a stabilizing N-terminal MIT-like domain and a catalytic C-terminal C2B-type HAD phosphatase fold. Structure-guided mutagenesis, combined with kinetic analyses using a designed competitive inhibitor, trehalose 6-sulfate, identified five residues important for binding and catalysis. This structure-function analysis along with computational mapping provided the basis for the proposed model of the T6PP-trehalose 6-phosphate complex. The model indicates a substrate-binding mode wherein shape complementarity and van der Waals interactions drive recognition. The mode of binding is in sharp contrast to the homolog sucrose-6-phosphate phosphatase where extensive hydrogen-bond interactions are made to the substrate. Together these results suggest that high-affinity inhibitors will be bi-dentate, taking advantage of substrate-like binding to the phosphoryl-binding pocket while simultaneously utilizing non-native binding to the trehalose pocket. The conservation of the key residues that enforce the shape of the substrate pocket in T6PP enzymes suggest that development of broad-range anthelmintic and antibacterial therapeutics employing this platform may be possible. PMID:24992307

  3. Structure of the trehalose-6-phosphate phosphatase from Brugia malayi reveals key design principles for anthelmintic drugs.

    PubMed

    Farelli, Jeremiah D; Galvin, Brendan D; Li, Zhiru; Liu, Chunliang; Aono, Miyuki; Garland, Megan; Hallett, Olivia E; Causey, Thomas B; Ali-Reynolds, Alana; Saltzberg, Daniel J; Carlow, Clotilde K S; Dunaway-Mariano, Debra; Allen, Karen N

    2014-07-01

    Parasitic nematodes are responsible for devastating illnesses that plague many of the world's poorest populations indigenous to the tropical areas of developing nations. Among these diseases is lymphatic filariasis, a major cause of permanent and long-term disability. Proteins essential to nematodes that do not have mammalian counterparts represent targets for therapeutic inhibitor discovery. One promising target is trehalose-6-phosphate phosphatase (T6PP) from Brugia malayi. In the model nematode Caenorhabditis elegans, T6PP is essential for survival due to the toxic effect(s) of the accumulation of trehalose 6-phosphate. T6PP has also been shown to be essential in Mycobacterium tuberculosis. We determined the X-ray crystal structure of T6PP from B. malayi. The protein structure revealed a stabilizing N-terminal MIT-like domain and a catalytic C-terminal C2B-type HAD phosphatase fold. Structure-guided mutagenesis, combined with kinetic analyses using a designed competitive inhibitor, trehalose 6-sulfate, identified five residues important for binding and catalysis. This structure-function analysis along with computational mapping provided the basis for the proposed model of the T6PP-trehalose 6-phosphate complex. The model indicates a substrate-binding mode wherein shape complementarity and van der Waals interactions drive recognition. The mode of binding is in sharp contrast to the homolog sucrose-6-phosphate phosphatase where extensive hydrogen-bond interactions are made to the substrate. Together these results suggest that high-affinity inhibitors will be bi-dentate, taking advantage of substrate-like binding to the phosphoryl-binding pocket while simultaneously utilizing non-native binding to the trehalose pocket. The conservation of the key residues that enforce the shape of the substrate pocket in T6PP enzymes suggest that development of broad-range anthelmintic and antibacterial therapeutics employing this platform may be possible.

  4. Comparative Genomics of a Plant-Parasitic Nematode Endosymbiont Suggest a Role in Nutritional Symbiosis

    PubMed Central

    Brown, Amanda M.V.; Howe, Dana K.; Wasala, Sulochana K.; Peetz, Amy B.; Zasada, Inga A.; Denver, Dee R.

    2015-01-01

    Bacterial mutualists can modulate the biochemical capacity of animals. Highly coevolved nutritional mutualists do this by synthesizing nutrients missing from the host’s diet. Genomics tools have advanced the study of these partnerships. Here we examined the endosymbiont Xiphinematobacter (phylum Verrucomicrobia) from the dagger nematode Xiphinema americanum, a migratory ectoparasite of numerous crops that also vectors nepovirus. Previously, this endosymbiont was identified in the gut, ovaries, and eggs, but its role was unknown. We explored the potential role of this symbiont using fluorescence in situ hybridization, genome sequencing, and comparative functional genomics. We report the first genome of an intracellular Verrucomicrobium and the first exclusively intracellular non-Wolbachia nematode symbiont. Results revealed that Xiphinematobacter had a small 0.916-Mb genome with only 817 predicted proteins, resembling genomes of other mutualist endosymbionts. Compared with free-living relatives, conserved proteins were shorter on average, and there was large-scale loss of regulatory pathways. Despite massive gene loss, more genes were retained for biosynthesis of amino acids predicted to be essential to the host. Gene ontology enrichment tests showed enrichment for biosynthesis of arginine, histidine, and aromatic amino acids, as well as thiamine and coenzyme A, diverging from the profiles of relatives Akkermansia muciniphilia (in the human colon), Methylacidiphilum infernorum, and the mutualist Wolbachia from filarial nematodes. Together, these features and the location in the gut suggest that Xiphinematobacter functions as a nutritional mutualist, supplementing essential nutrients that are depleted in the nematode diet. This pattern points to evolutionary convergence with endosymbionts found in sap-feeding insects. PMID:26362082

  5. Comparative Genomics of a Plant-Parasitic Nematode Endosymbiont Suggest a Role in Nutritional Symbiosis.

    PubMed

    Brown, Amanda M V; Howe, Dana K; Wasala, Sulochana K; Peetz, Amy B; Zasada, Inga A; Denver, Dee R

    2015-09-01

    Bacterial mutualists can modulate the biochemical capacity of animals. Highly coevolved nutritional mutualists do this by synthesizing nutrients missing from the host's diet. Genomics tools have advanced the study of these partnerships. Here we examined the endosymbiont Xiphinematobacter (phylum Verrucomicrobia) from the dagger nematode Xiphinema americanum, a migratory ectoparasite of numerous crops that also vectors nepovirus. Previously, this endosymbiont was identified in the gut, ovaries, and eggs, but its role was unknown. We explored the potential role of this symbiont using fluorescence in situ hybridization, genome sequencing, and comparative functional genomics. We report the first genome of an intracellular Verrucomicrobium and the first exclusively intracellular non-Wolbachia nematode symbiont. Results revealed that Xiphinematobacter had a small 0.916-Mb genome with only 817 predicted proteins, resembling genomes of other mutualist endosymbionts. Compared with free-living relatives, conserved proteins were shorter on average, and there was large-scale loss of regulatory pathways. Despite massive gene loss, more genes were retained for biosynthesis of amino acids predicted to be essential to the host. Gene ontology enrichment tests showed enrichment for biosynthesis of arginine, histidine, and aromatic amino acids, as well as thiamine and coenzyme A, diverging from the profiles of relatives Akkermansia muciniphilia (in the human colon), Methylacidiphilum infernorum, and the mutualist Wolbachia from filarial nematodes. Together, these features and the location in the gut suggest that Xiphinematobacter functions as a nutritional mutualist, supplementing essential nutrients that are depleted in the nematode diet. This pattern points to evolutionary convergence with endosymbionts found in sap-feeding insects.

  6. Variation and polymorphism in helminth parasites.

    PubMed

    Maizels, R M; Kurniawan-Atmadja, A

    2002-01-01

    There are strong biological, evolutionary and immunological arguments for predicting extensive polymorphism among helminth parasites, but relatively little data and few instances from which the selective forces acting on parasite diversity can be discerned. The paucity of information on intraspecific variation stands in contrast to the fine detail with which helminth species have been delineated by morphological techniques, accentuating a trend towards considering laboratory strains as representative of a relatively invariant organism. However, in the fast-moving evolutionary race between host and parasite one would predict a monomorphic species would be driven to extinction. We review the arena of intraspecific variation for the major helminth parasites, ranging from biological properties such as host or vector preference, to biochemical and immunological characteristics, as well as molecular markers such as DNA sequence variants. These data are summarized, before focusing in more detail on polymorphisms within protein-coding genes of potential relevance to the host-parasite relationship, such as vaccine candidates. In particular, we discuss the available data on a number of major antigens from the filarial nematode Brugia malayi. Information is currently too sparse to answer the question of whether there is antigenic variation in filariasis, but the indications are that proteins from the blood-borne microfilarial stage show significant intraspecific variability. Future work will define whether polymorphisms in these antigens may be driven by exposure to the host immune response or reflect some other facet of parasite biology.

  7. Nematodetoxic aurovertin-type metabolites from a root-knot nematode parasitic fungus Pochonia chlamydosporia.

    PubMed

    Niu, Xue-Mei; Wang, Yan-Li; Chu, Yan-Sheng; Xue, Hua-Xi; Li, Nan; Wei, Lu-Xia; Mo, Ming-He; Zhang, Ke-Qin

    2010-01-27

    Chemical investigation of one fungal strain P. chlamydosporia YMF 1.00613 isolated from root knots of tobacco infected by Meloidogyne incognita led to the isolation and identification of four aurovertin-type metabolites, which include a new compound, aurovertin I (A1), and three known metabolites, aurovertins E, F and D (A2-A4). Their structures were established by spectroscopic studies such as 1D- and 2D-NMR and MS analysis. Aurovertin I (A1) is the first natural product with an aurovertin skeleton with one less carbon. Compounds A3 and A4 showed the toxicity to the worms of the free-living nematode Panagrellus redivevus with the LC(50) values 88.6 and 41.7 microg/mL at 48 h, respectively. All four aurovertins did not show obvious inhibitory effects on egg hatch of root knot nematode Meloidogyne incognita. The results suggested that the aurovertin-type metabolites produced by P. chlamydosporia might be one of the pathogenic factors involved in the suppression of nematodes.

  8. Macrocyclic Lactones Differ in Interaction with Recombinant P-Glycoprotein 9 of the Parasitic Nematode Cylicocylus elongatus and Ketoconazole in a Yeast Growth Assay

    PubMed Central

    Kaschny, Maximiliane; Demeler, Janina; Janssen, I. Jana I.; Kuzmina, Tetiana A.; Besognet, Bruno; Kanellos, Theo; Kerboeuf, Dominique; von Samson-Himmelstjerna, Georg; Krücken, Jürgen

    2015-01-01

    Macrocyclic lactones (MLs) are widely used parasiticides against nematodes and arthropods, but resistance is frequently observed in parasitic nematodes of horses and livestock. Reports claiming resistance or decreased susceptibility in human nematodes are increasing. Since no target site directed ML resistance mechanisms have been identified, non-specific mechanisms were frequently implicated in ML resistance, including P-glycoproteins (Pgps, designated ABCB1 in vertebrates). Nematode genomes encode many different Pgps (e.g. 10 in the sheep parasite Haemonchus contortus). ML transport was shown for mammalian Pgps, Pgps on nematode egg shells, and very recently for Pgp-2 of H. contortus. Here, Pgp-9 from the equine parasite Cylicocyclus elongatus (Cyathostominae) was expressed in a Saccharomyces cerevisiae strain lacking seven endogenous efflux transporters. Pgp was detected on these yeasts by flow cytometry and chemiluminescence using the monoclonal antibody UIC2, which is specific for the active Pgp conformation. In a growth assay, Pgp-9 increased resistance to the fungicides ketoconazole, actinomycin D, valinomycin and daunorubicin, but not to the anthelmintic fungicide thiabendazole. Since no fungicidal activity has been described for MLs, their interaction with Pgp-9 was investigated in an assay involving two drugs: Yeasts were incubated with the highest ketoconazole concentration not affecting growth plus increasing concentrations of MLs to determine competition between or modulation of transport of both drugs. Already equimolar concentrations of ivermectin and eprinomectin inhibited growth, and at fourfold higher ML concentrations growth was virtually abolished. Selamectin and doramectin did not increase susceptibility to ketoconazole at all, although doramectin has been shown previously to strongly interact with human and canine Pgp. An intermediate interaction was observed for moxidectin. This was substantiated by increased binding of UIC2 antibodies in the

  9. Expression of five acetylcholine receptor subunit genes in Brugia malayi adult worms.

    PubMed

    Li, Ben-Wen; Rush, Amy C; Weil, Gary J

    2015-12-01

    Acetylcholine receptors (AChRs) are required for body movement in parasitic nematodes and are targets of "classical" anthelmintic drugs such as levamisole and pyrantel and of newer drugs such as tribendimidine and derquantel. While neurotransmission explains the effects of these drugs on nematode movement, their effects on parasite reproduction are unexplained. The levamisole AChR type (L-AChRs) in Caenorhabditis elegans is comprised of five subunits: Cel-UNC-29, Cel-UNC-38, Cel-UNC-63, Cel-LEV-1 and Cel-LEV-8. The genome of the filarial parasite Brugia malayi contains nine AChRs subunits including orthologues of Cel-unc-29, Cel-unc-38, and Cel-unc-63. We performed in situ hybridization with RNA probes to localize the expression of five AChR genes (Bm1_35890-Bma-unc-29, Bm1_20330-Bma-unc-38, Bm1_38195-Bma-unc-63, Bm1_48815-Bma-acr-26 and Bm1_40515-Bma-acr-12) in B. malayi adult worms. Four of these genes had similar expression patterns with signals in body muscle, developing embryos, spermatogonia, uterine wall adjacent to stretched microfilariae, wall of V as deferens, and lateral cord. Three L-AChR subunit genes (Bma-unc-29, Bma-unc-38 and Bma-unc-63) were expressed in body muscle, which is a known target of levamisole. Bma-acr-12 was co-expressed with these levamisole subunit genes in muscle, and this suggests that its protein product may form receptors with other alpha subunits. Bma-acr-26 was expressed in male muscle but not in female muscle. Strong expression signals of these genes in early embryos and gametes in uterus and testis suggest that AChRs may have a role in nervous system development of embryogenesis and spermatogenesis. This would be consistent with embryotoxic effects of drugs that target these receptors in filarial worms. Our data show that the expression of these receptor genes is tightly regulated with regard to localization in adult worms and developmental stage in embryos and gametes. These results may help to explain the broad effects of

  10. Is the morphology of Culicoides intersexes parasitized by mermithid nematodes a parasite adaptation? A morphometric approach to Culicoides circumscriptus (Diptera: Ceratopogonidae).

    PubMed

    Muñoz-Muñoz, Francesc; Ramoneda, Josep; Pagès, Nonito; Pujol, Nuria; Talavera, Sandra

    2016-03-01

    Mermithidae is a family of endoparasitic nematodes known to cause intersexuality in arthropods. Intersexes of the genus Culicoides parasitized by mermithids have been the object of several studies aiming to describe their particular morphology. Culicoides intersexes are specimens with male genitalia and feminized sexually dimorphic structures, i.e. antennae, mouthparts and wings. To date, these specimens have only been described qualitatively and a quantitative approach supported by statistical analysis is lacking. Here we conduct morphometric analyses of sexually dimorphic structures in a sample of Culicoides circumscriptus that includes 34 intersexes with the aim of describing precisely the intersexual morphology. The morphology of antennae and the mouthparts was studied by multivariate statistical analysis of linear measures, and wing form by implementing geometric morphometrics techniques. While intersex wings proved to have a similar size to male wings, their shape was intermediate between males and females. However, when allometric shape variation was removed, the wing shape of intersexes was almost identical to that of females. The intersex antennae were morphometrically of the female type, especially when size variation was considered. In contrast, the measured mouthparts (the labrum and the third palpal segment) were halfway between males and females, even when body size was considered. Overall, the antennae and the wings showed a higher degree of feminization than the mouthparts. These findings indicate that the degree of feminization depends both on the morphological structure and on body size. Moreover, we propose that the feminization of the wings and antennae has an adaptive meaning for the parasite, which would favor female-like traits in order to access more easily its breeding sites, where the parasite has plenty of new hosts to infect. Female-like antennae would be beneficial to detect these sites, while having female-like wings would favor the

  11. Molecular Characterization and Phylogenetic Evaluation of the Hsp90 Gene from Selected Nematodes

    PubMed Central

    Skantar, Andrea M.; Carta, Lynn K.

    2004-01-01

    While multiple genes are optimal for corroborating nematode phylogenies, only a few are commonly used. Here we examine the phylogenetic potential of the nuclear Hsp90 chaperone gene. We used degenerate primers to obtain partial Hsp90 sequences from several plant-parasitic and free-living nematodes. Hsp90 was single-copy in Heterodera glycines and Meloidogyne javanica, similar to the situation for Caenorhabditis elegans. The full-length H. glycines Hsp90 protein sequence showed homology to sequences from C. elegans and Brugia pahangi and to other eukaryotes, and contains several functionally important regions common to cytoplasmic Hsp90 proteins. The Hsp90 amino acid phylogeny supported the Coelomata hypothesis for metazoan evolution. Phylogenetic trees, substitution scatter plots, and statistics for phylogenetic signal were made for Hsp90, 18S small subunit (SSU), and 28S large subunit (LSU) over a limited but broad sampling of nematode taxa. Only the LSU data set failed to recover any of the expected topology and showed extensive substitution saturation. In an intensive sampling of plant-parasitic nematode taxa, the Hsp90 tree topologies were generally congruent with rDNA results and alignments were unambiguous. Hsp90 sequences may help strengthen branch support or clarify tree topologies when other molecules show ambiguous alignments, greater branch-length heterogeneity, or codon bias in certain taxonomic groups. PMID:19262827

  12. Nematodes parasitizing Trachurus trachurus (L.) and Boops boops (L.) from Algeria.

    PubMed

    Ichalal, Keltoum; Ramdane, Zouhir; Ider, Djamila; Kacher, Mohammed; Iguerouada, Mokrane; Trilles, Jean-Paul; Courcot, Luci; Amara, Rachid

    2015-11-01

    A total of 455 Boops boops (Linnaeus, 1758) and 953 Trachurus trachurus Linnaeus, 1758 from the east coast of Algeria were examined for their parasitic Nematoda. Two hundred ninety-five specimens of larval stages L3 and L4 were collected from the peritoneal cavity of these two examined fishes. Photonic and scanning electronic microscopy (SEM) studies were performed on these larvae specimens in order to characterize their morphology. Two different species of Nematoda (Anisikidae) were identified: Anisakis simplex (Rudolphi, 1809) and Hysterothylacium aduncum (Rudolphi, 1802). These two parasitic species were reported for the first time on T. trachurus and B. boops from the eastern coast of Algeria. These parasites were attached on different organs in the abdominal cavity (particularly on ovaries and testes). The infestation rate changed according to the month and the host size. The parasitism did not show a significant negative impact on the condition of the examined fishes.

  13. Nematodes parasitizing Trachurus trachurus (L.) and Boops boops (L.) from Algeria.

    PubMed

    Ichalal, Keltoum; Ramdane, Zouhir; Ider, Djamila; Kacher, Mohammed; Iguerouada, Mokrane; Trilles, Jean-Paul; Courcot, Luci; Amara, Rachid

    2015-11-01

    A total of 455 Boops boops (Linnaeus, 1758) and 953 Trachurus trachurus Linnaeus, 1758 from the east coast of Algeria were examined for their parasitic Nematoda. Two hundred ninety-five specimens of larval stages L3 and L4 were collected from the peritoneal cavity of these two examined fishes. Photonic and scanning electronic microscopy (SEM) studies were performed on these larvae specimens in order to characterize their morphology. Two different species of Nematoda (Anisikidae) were identified: Anisakis simplex (Rudolphi, 1809) and Hysterothylacium aduncum (Rudolphi, 1802). These two parasitic species were reported for the first time on T. trachurus and B. boops from the eastern coast of Algeria. These parasites were attached on different organs in the abdominal cavity (particularly on ovaries and testes). The infestation rate changed according to the month and the host size. The parasitism did not show a significant negative impact on the condition of the examined fishes. PMID:26220559

  14. SOME ASPECTS OF THE NATURAL CONTROL OF PLANT PARASITIC NEMATODES IN SOIL UNDER BROAD BEAN VICIA FABA L. CULTIVATED IN CROP ROTATION AND LONG-TERM MONOCULTURE.

    PubMed

    Skwiercz, A T; Damszel, M; Stefanovska, T; Rychcik, B

    2015-01-01

    Observations on population density of plant parasitic nematodes occurring in rhizosphere of broad bean cultivated in the crop rotation and long-term monoculture were performed during 2013-2014. 13 species were observed: Trichodorus primitivus, T. viruliferus, Paratrichodorus pachydermus, Criconema annuliferum, Paratylenchus projectus, Bitylenchus dubius, Merlinius brevidens, Pratylenchus fallax, P. flakkensis, P. neglectus, Heterodera triffolii, H. goettingiana, and Ditylenchus dipsaci. In monoculture plots 70-80% of eggs inside Heterodera cysts were colonized by pathogenic fungi (v.s. 50-62% of cysts from crop rotation). 12-18% of specimens of Pratylenchus species were colonized by the nematode-pathogenic bacteria: Bacillus penetrans.

  15. Advances and trends in the molecular systematics of anisakid nematodes, with implications for their evolutionary ecology and host-parasite co-evolutionary processes.

    PubMed

    Mattiucci, Simonetta; Nascetti, Giuseppe

    2008-01-01

    The application of molecular systematics to the anisakid nematodes of the genera Anisakis, Pseudoterranova and Contracaecum, parasites of aquatic organisms, over the last two decades, has advanced the understanding of their systematics, taxonomy, ecology and phylogeny substantially. Here the results of this effort on this group of species from the early genetic works to the current status of their revised taxonomy, ecology and evolutionary aspects are reviewed for each of three parasitic groups. It has been shown that many anisakid morphospecies of Anisakis, Contracaecum and Pseudoterranova include a certain number of sibling species. Molecular genetic markers provided a rapid, precise means to screen and identify several species that serve as definitive and intermediate and or/paratenic hosts of the so far genetically characterized species. Patterns of differential distribution of anisakid nematodes in various definitive and intermediate hosts are presented. Differences in the life history of related species can be due both to differential host-parasite co-adaptation and co-evolution, and/or to interspecific competition, that can reduce the range of potential hosts in sympatric conditions. Phylogenetic hypotheses attempted for anisakid nematodes and the possible evolutionary scenarios that have been proposed inferred from molecular data, also with respect to the phylogeny of their hosts are presented for the parasite-host associations Anisakis-cetaceans and Contracaecum-pinnipeds, showing that codivergence and host-switching events could have accompanied the evolution of these groups of parasites. Finally, examples in which anisakid nematodes recognized genetically at the species level in definitive and intermediate/paratenic hosts from various geographical areas of the Boreal and Austral regions and their infection levels have been used as biological indicators of fish stocks and food-web integrity in areas at high versus low levels of habitat disturbance

  16. Targeting Lysine Deacetylases (KDACs) in Parasites.

    PubMed

    Wang, Qi; Rosa, Bruce A; Nare, Bakela; Powell, Kerrie; Valente, Sergio; Rotili, Dante; Mai, Antonello; Marshall, Garland R; Mitreva, Makedonka

    2015-01-01

    Due to an increasing problem of drug resistance among almost all parasites species ranging from protists to worms, there is an urgent need to explore new drug targets and their inhibitors to provide new and effective parasitic therapeutics. In this regard, there is growing interest in exploring known drug leads of human epigenetic enzymes as potential starting points to develop novel treatments for parasitic diseases. This approach of repurposing (starting with validated targets and inhibitors) is quite attractive since it has the potential to reduce the expense of drug development and accelerate the process of developing novel drug candidates for parasite control. Lysine deacetylases (KDACs) are among the most studied epigenetic drug targets of humans, and a broad range of small-molecule inhibitors for these enzymes have been reported. In this work, we identify the KDAC protein families in representative species across important classes of parasites, screen a compound library of 23 hydroxamate- or benzamide-based small molecules KDAC inhibitors, and report their activities against a range of parasitic species, including the pathogen of malaria (Plasmodium falciparum), kinetoplastids (Trypanosoma brucei and Leishmania donovani), and nematodes (Brugia malayi, Dirofilaria immitis and Haemonchus contortus). Compound activity against parasites is compared to that observed against the mammalian cell line (L929 mouse fibroblast) in order to determine potential parasite-versus-host selectivity). The compounds showed nanomolar to sub-nanomolar potency against various parasites, and some selectivity was observed within the small panel of compounds tested. The possible binding modes of the active compounds at the different protein target sites within different species were explored by docking to homology models to help guide the discovery of more selective, parasite-specific inhibitors. This current work supports previous studies that explored the use of KDAC inhibitors in

  17. Transcriptome analysis of stress tolerance in entomopathogenic nematodes of the genus Steinernema.

    PubMed

    Yaari, Mor; Doron-Faigenboim, Adi; Koltai, Hinanit; Salame, Liora; Glazer, Itamar

    2016-02-01

    Entomopathogenic nematodes of the genus Steinernema are effective biological control agents. The infective stage of these parasites can withstand environmental stresses such as desiccation and heat, but the molecular and physiological mechanisms involved in this tolerance are poorly understood. We used 454 pyrosequencing to analyse transcriptome expression in Steinernema spp. that differ in their tolerance to stress. We compared these species, following heat and desiccation treatments, with their non-stressed counterparts. More than 98% of the transcripts found matched homologous sequences in the UniRef90 database, mostly nematode genes (85%). Among those, 60.8% aligned to the vertebrate parasites including Ascaris suum, Loa loa, and Brugia malayi, 23.3% aligned to bacteriovores, mostly from the genus Caenorhabditis, and 1% aligned to EPNs. Analysing gene expression patterns of the stress response showed a large fraction of down-regulated genes in the desiccation-tolerant nematode Steinernema riobrave, whereas a larger fraction of the genes in the susceptible Steinernema feltiae Carmiel and Gvulot strains were up-regulated. We further compared metabolic pathways and the expression of specific stress-related genes. In the more tolerant nematode, more genes were down-regulated whereas in the less tolerant strains, more genes were up-regulated. This phenomenon warrants further exploration of the mechanism governing induction of the down-regulation process. The present study revealed many genes and metabolic cycles that are differentially expressed in the stressed nematodes. Some of those are well known in other nematodes or anhydrobiotic organisms, but several are new and should be further investigated for their involvement in desiccation and heat tolerance. Our data establish a foundation for further exploration of stress tolerance in entomopathogenic nematodes and, in the long term, for improving their ability to withstand suboptimal environmental conditions. PMID

  18. A survey on anthelmintic resistance in nematode parasites of sheep in the Slovak Republic.

    PubMed

    Cernanská, D; Várady, M; Corba, J

    2006-01-15

    The prevalence of anthelmintic resistance on 27 sheep farms in Slovakia was investigated in 2003 and 2004 using the faecal egg count reduction test (FECRT) according to the WAAVP guidelines. Resistance to albendazole was detected on one farm (3.7%) and suspected on two farms (7.4%) out of 27 sheep flocks. Resistance to ivermectin was tested on 26 farms. On six (23.1%) farms, results indicated the presence of ivermectin resistance. Resistance to ivermectin was suspected on eight farms (30.8%). However, it is also possible that generic ivermectin anthelmintics used in survey have a lower efficacy against sheep nematodes.

  19. Nematicidal Injection: Targeted Control of Plant-Parasitic Nematodes of Trees and Vines

    PubMed Central

    Viglierchio, D. R.; Maggenti, A. R.; Schmittt, R. V.; Paxman, G. A.

    1977-01-01

    Pressurized injection of nematicidal solutions was effective for control of nematodes within trees and vines. Significant (P = 0.01) control of Pratylenchus vulnus on grape was attained with four nonfumigants (carbofuran, oxamyl, phenamiphos, and sulfocarb) and one fumigant nematicide (DBCP). Pratylenchus penetrans was controlled (P = 0.05 and 0.1) in apples and walnuts with sulfocarh and oxamyl. This species also was controlled in apples with carbofuran and phenamiphos. The advantages of pressure injection over traditional methods of nematicide applications are discussed. PMID:19305613

  20. Molecular survey of trichostrongyle nematodes in a Bison bison herd experiencing clinical parasitism, and effects of avermectin treatment.

    PubMed

    Eljaki, A A; Al Kappany, Y M; Grosz, D D; Smart, A J; Hildreth, M B

    2016-08-30

    North American bison (Bison bison) producers face many challenges, including the potential clinical and economics problems caused by trichostrongyle nematodes within their herds. Little is known about the prevalence, intensity, geographical distribution and clinical significance of these parasites in commercial bison herds, even from regions where bison production has become popular. This study involved a large herd of bison from eastern South Dakota that was experiencing clinical parasitism due to a temporary over-stocking problem. After documenting fecal egg counts (FECs) and trichostrongyle genera present among the 3 main age-categories (i.e. adults, yearlings, calves) of bison during this heavily infected grazing season, the effects of doramectin treatment on the different age groups was also evaluated. This is the first bison study using PCR to identify genera of trichostrongyles in fecal samples. Virtually all 103 bison fecal samples from all 3 age classes were shedding trichostrongyle eggs by the end of the season, and the mean FECs were 34 eggs/g (EPG) among the cows, 125 EPG in the yearlings, and 186 EGP among calves. Based upon this heavily-infected herd, there is evidence that the susceptibility of bison to trichostrongyles is more similar to beef cattle than to sheep. Other parasites such as Moniezia, Nematodirus, Trichuris, and coccidians were also identified in these samples. All but 3 of the 51 samples analyzed with PCR shown at least 1 trichostrongyle genera. Ostertagia was detected in 68.6% of the samples, Cooperia in 80.39%, Haemonchus in at least 73% and Trichostrongylus in 16% of the herd. Most commonly, bison were infected with combinations of Haemonchus/Ostertagia/Cooperia. After treatment with doramectin, the mean FECs dropped by 99.9% for all of the bison age classes. PMID:27523937

  1. Utilization of computer processed high definition video imaging for measuring motility of microscopic nematode stages on a quantitative scale: "The Worminator".

    PubMed

    Storey, Bob; Marcellino, Chris; Miller, Melissa; Maclean, Mary; Mostafa, Eman; Howell, Sue; Sakanari, Judy; Wolstenholme, Adrian; Kaplan, Ray

    2014-12-01

    A major hindrance to evaluating nematode populations for anthelmintic resistance, as well as for screening existing drugs, new compounds, or bioactive plant extracts for anthelmintic properties, is the lack of an efficient, objective, and reproducible in vitro assay that is adaptable to multiple life stages and parasite genera. To address this need we have developed the "Worminator" system, which objectively and quantitatively measures the motility of microscopic stages of parasitic nematodes. The system is built around the computer application "WormAssay", developed at the Center for Discovery and Innovation in Parasitic Diseases at the University of California, San Francisco. WormAssay was designed to assess motility of macroscopic parasites for the purpose of high throughput screening of potential anthelmintic compounds, utilizing high definition video as an input to assess motion of adult stage (macroscopic) parasites (e.g. Brugia malayi). We adapted this assay for use with microscopic parasites by modifying the software to support a full frame analysis mode that applies the motion algorithm to the entire video frame. Thus, the motility of all parasites in a given well are recorded and measured simultaneously. Assays performed on third-stage larvae (L3) of the bovine intestinal nematode Cooperia spp., as well as microfilariae (mf) of the filarioid nematodes B. malayi and Dirofilaria immitis, yielded reproducible dose responses using the macrocyclic lactones ivermectin, doramectin, and moxidectin, as well as the nicotinic agonists, pyrantel, oxantel, morantel, and tribendimidine. This new computer based-assay is simple to use, requires minimal new investment in equipment, is robust across nematode genera and developmental stage, and does not require subjective scoring of motility by an observer. Thus, the "Worminator" provides a relatively low-cost platform for developing genera- and stage-specific assays with high efficiency and reproducibility, low labor input

  2. Utilization of computer processed high definition video imaging for measuring motility of microscopic nematode stages on a quantitative scale: “The Worminator”

    PubMed Central

    Storey, Bob; Marcellino, Chris; Miller, Melissa; Maclean, Mary; Mostafa, Eman; Howell, Sue; Sakanari, Judy; Wolstenholme, Adrian; Kaplan, Ray

    2014-01-01

    A major hindrance to evaluating nematode populations for anthelmintic resistance, as well as for screening existing drugs, new compounds, or bioactive plant extracts for anthelmintic properties, is the lack of an efficient, objective, and reproducible in vitro assay that is adaptable to multiple life stages and parasite genera. To address this need we have developed the “Worminator” system, which objectively and quantitatively measures the motility of microscopic stages of parasitic nematodes. The system is built around the computer application “WormAssay”, developed at the Center for Discovery and Innovation in Parasitic Diseases at the University of California, San Francisco. WormAssay was designed to assess motility of macroscopic parasites for the purpose of high throughput screening of potential anthelmintic compounds, utilizing high definition video as an input to assess motion of adult stage (macroscopic) parasites (e.g. Brugia malayi). We adapted this assay for use with microscopic parasites by modifying the software to support a full frame analysis mode that applies the motion algorithm to the entire video frame. Thus, the motility of all parasites in a given well are recorded and measured simultaneously. Assays performed on third-stage larvae (L3) of the bovine intestinal nematode Cooperia spp., as well as microfilariae (mf) of the filarioid nematodes B. malayi and Dirofilaria immitis, yielded reproducible dose responses using the macrocyclic lactones ivermectin, doramectin, and moxidectin, as well as the nicotinic agonists, pyrantel, oxantel, morantel, and tribendimidine. This new computer based-assay is simple to use, requires minimal new investment in equipment, is robust across nematode genera and developmental stage, and does not require subjective scoring of motility by an observer. Thus, the “Worminator” provides a relatively low-cost platform for developing genera- and stage-specific assays with high efficiency and reproducibility, low

  3. Occurrence, Parasitism, and Pathogenicity of Nematodes Associated with Sycamore (Platanus occidentalis L.).

    PubMed

    Churchill, R C; Ruehle, J L

    1971-04-01

    Ten species of stylet-bearing nematodes were recovered in a survey of sycamore (Platanus occidentalis L. ) stands in Georgia. Helicotylenchus, Xiphinema, and Criconemoides were the genera found most frequently. Populations of Hoplolaimus galeatus, Scutellonema brachyurum, Helicotylenchus dihystera and H. pseudorobustus increased on greenhouse-grown sycamore, but Trichodorus christiei, Xiphinema americanum, Meloidogyne hapla, M. arenaria and M. incognita did not. Hoplolaimus galeatus and S. brachyurum are semi-endoparasites; H. dihystera and H. pseudorobustus are migratory endoparasites. Hoplolaimus galeatus caused extensive root necrosis and marked decrease of fresh weights of seedling roots and tops. Helicotylenchus dihystera and S. brachyurum produced only qualitatively different sparse and unhealthy root growth. Helicotylenchus pseudorobustus caused only a reduction in root surface area.

  4. A Proteomic Analysis of the Body Wall, Digestive Tract, and Reproductive Tract of Brugia malayi

    PubMed Central

    Morris, C. Paul; Bennuru, Sasisekhar; Kropp, Laura E.; Zweben, Jesse A.; Meng, Zhaojing; Taylor, Rebekah T.; Chan, King; Veenstra, Timothy D.; Nutman, Thomas B.; Mitre, Edward

    2015-01-01

    Filarial worms are parasitic nematodes that cause devastating diseases such as lymphatic filariasis (LF) and onchocerciasis. Filariae are nematodes with complex anatomy including fully developed digestive tracts and reproductive organs. To better understand the basic biology of filarial parasites and to provide insights into drug targets and vaccine design, we conducted a proteomic analysis of different anatomic fractions of Brugia malayi, a causative agent of LF. Approximately 500 adult female B. malayi worms were dissected, and three anatomical fractions (body wall, digestive tract, and reproductive tract) were obtained. Proteins from each anatomical fraction were extracted, desalted, trypsinized, and analyzed by microcapillary reverse-phase liquid chromatography-tandem-mass spectrometry. In total, we identified 4,785 B. malayi proteins. While 1,894 were identified in all three anatomic fractions, 396 were positively identified only within the digestive tract, 114 only within the body wall, and 1,011 only within the reproductive tract. Gene set enrichment analysis revealed a bias for transporters to be present within the digestive tract, suggesting that the intestine of adult filariae is functional and important for nutrient uptake or waste removal. As expected, the body wall exhibited increased frequencies of cytoskeletal proteins, and the reproductive tract had increased frequencies of proteins involved in nuclear regulation and transcription. In assessing for possible vaccine candidates, we focused on proteins sequestered within the digestive tract, as these could possibly represent “hidden antigens” with low risk of prior allergic sensitization. We identified 106 proteins that are enriched in the digestive tract and are predicted to localize to the surface of cells in the the digestive tract. It is possible that some of these proteins are on the luminal surface and may be accessible by antibodies ingested by the worm. A subset of 27 of these proteins

  5. Formicitylenchus oregonensis n. g., n. sp. (Allantonematidae: Nematoda), the first tylenchid parasite of ants, with a review of nematodes described from ants.

    PubMed

    Poinar, George

    2003-09-01

    The first tylenchid parasite of ants, Formicitylenchus oregonensis n. g., n. sp., is described from a queen carpenter ant Camponotus vicinus Mayr in Western Oregon, USA. The new genus is characterised by the excretory pore anterior to the nerve-ring and rounded tails in the free-living adults, a stylet bearing basal thickenings in the free-living female, a smaller stylet lacking basal thickenings in the male and a short, crenulate leptoderan bursa. The mature parasitic female is light yellow and ovoviviparous. F. oregonensis n. sp. is closely related to members of Metaparasitylenchus Wachek, 1955, with species parasitising beetles living under bark or in rotten wood, a habitat similar to that of carpenter ants. However, males of Metaparasitylenchus are characterised by a fairly long tail with a broad peloderan bursa. It is suggested that this case of tylenchid parasitism in ants is an example of environmental host selection. A review of the described nematode parasites of ants is presented.

  6. Helminth parasites in ringed seals (Pusa hispida) from Svalbard, Norway with special emphasis on nematodes: variation with age, sex, diet, and location of host.

    PubMed

    Johansen, Carina E; Lydersen, Christian; Aspholm, Paul E; Haug, Tore; Kovacs, Kit M

    2010-10-01

    Complete gastrointestinal tracts from 257 ringed seals (Pusa hispida) from Svalbard, Norway, were examined for helminth parasites. Three different helminth groups were recorded (acanthocephalans 61.1%; nematodes 38%; cestodes 0.9%). Acanthocephalans (Polymorphidae) and cestodes (Anophryocephalus and Diphyllobothrium sp(p)., as well as unidentified species, were confined to the intestines. The anisakid nematodes Phocascaris phocae, Pseudoterranova sp(p)., Anisakis sp(p)., and Phocascaris/Contracaecum sp(p). were recorded in both stomachs and the anterior part of the small intestines. The abundance of nematodes and acanthocephalans varied significantly with sampling location of the seal hosts. This is likely due to the relative prevalence of Arctic versus Atlantic water in the different fjord systems, which strongly influences the age class and species of fish available as prey for the seals. Adult male ringed seals had significantly higher abundances of nematodes than did adult females or juveniles. Adult males also had significantly higher abundances of acanthocephalans than did adult females, but were not significantly different from juveniles in this regard. Nematode abundance increased significantly with age of male hosts, but this trend was lacking in female seals. Infection parameters appeared to be related to differences in the age of polar cod (Boreogadus saida) exploited by male, female, and juvenile seals.

  7. Species of Root-knot Nematodes and Fungal Egg Parasites Recovered from Vegetables in Almería and Barcelona, Spain

    PubMed Central

    Verdejo-Lucas, S.; Ornat, C.; Sorribas, F. J.; Stchiegel, A.

    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 numbers than cucurbit crops in Almería but not in Barcelona. Fungal parasites were found in 37% and 45% of the sites in Almería and Barcelona, respectively, but percent parasitism was never greater than 5%. Nine fungal species were isolated from single eggs of the nematode. The fungi included Verticillium chlamydosporium, V. catenulatum, Fusarium oxysporum, F. solani, Fusarium spp., Acremonium strictum, Gliocladium roseum, Cylindrocarpon spp., Engiodontium album, and Dactylella oviparasitica. Two sterile fungi and five unidentified fungi also were isolated from Meloidogyne spp. eggs. PMID:19265964

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

    PubMed

    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

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

    PubMed

    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

  10. Plant resistance against the parasitic nematode Heterodera schachtii is mediated by MPK3 and MPK6 kinases, which are controlled by the MAPK phosphatase AP2C1 in Arabidopsis

    PubMed Central

    Sidonskaya, Ekaterina; Schweighofer, Alois; Shubchynskyy, Volodymyr; Kammerhofer, Nina; Hofmann, Julia; Wieczorek, Krzysztof; Meskiene, Irute

    2016-01-01

    Plant-parasitic cyst nematodes infect plants and form highly sophisticated feeding sites in roots. It is not known which plant cell signalling mechanisms trigger plant defence during the early stages of nematode parasitism. Mitogen-activated protein kinases (MAPKs) are central components of protein phosphorylation cascades transducing extracellular signals to plant defence responses. MAPK phosphatases control kinase activities and the signalling outcome. The involvement and the role of MPK3 and MPK6, as well as the MAPK phosphatase AP2C1, is demonstrated during parasitism of the beet cyst nematode Heterodera schachtii in Arabidopsis. Our data reveal notable activation patterns of plant MAPKs and the induction of AP2C1 suggesting the attenuation of defence signalling in plant cells during early nematode infection. It is demonstrated that the ap2c1 mutant that is lacking AP2C1 is more attractive but less susceptible to nematodes compared with the AP2C1-overexpressing line. This implies that the function of AP2C1 is a negative regulator of nematode-induced defence. By contrast, the enhanced susceptibility of mpk3 and mpk6 plants indicates a positive role of stress-activated MAPKs in plant immunity against nematodes. Evidence is provided that phosphatase AP2C1, as well as AP2C1-targeted MPK3 and MPK6, are important regulators of plant–nematode interaction, where the co-ordinated action of these signalling components ensures the timely activation of plant defence. PMID:26438412

  11. Potential involvement of Brugia malayi cysteine proteases in the maintenance of the endosymbiotic relationship with Wolbachia.

    PubMed

    Lustigman, Sara; Melnikow, Elena; Anand, Setty Balakrishnan; Contreras, Aroha; Nandi, Vijay; Liu, Jing; Bell, Aaron; Unnasch, Thomas R; Rogers, Mathew B; Ghedin, Elodie

    2014-12-01

    Brugia malayi, a parasitic nematode that causes lymphatic filariasis, harbors endosymbiotic intracellular bacteria, Wolbachia, that are required for the development and reproduction of the worm. The essential nature of this endosymbiosis led to the development of anti-Wolbachia chemotherapeutic approaches for the treatment of human filarial infections. Our study is aimed at identifying specific proteins that play a critical role in this endosymbiotic relationship leading to the identification of potential targets in the adult worms. Filarial cysteine proteases are known to be involved in molting and embryogenesis, processes shown to also be Wolbachia dependent. Based on the observation that cysteine protease transcripts are differentially regulated in response to tetracycline treatment, we focused on defining their role in symbiosis. We observe a bimodal regulation pattern of transcripts encoding cysteine proteases when in vitro tetracycline treated worms were examined. Using tetracycline-treated infertile female worms and purified embryos we established that the first peak of the bimodal pattern corresponds to embryonic transcripts while the second takes place within the hypodermis of the adult worms. Localization studies of the native proteins corresponding to Bm-cpl-3 and Bm-cpl-6 indicate that they are present in the area surrounding Wolbachia, and, in some cases, the proteins appear localized within the bacteria. Both proteins were also found in the inner bodies of microfilariae. The possible role of these cysteine proteases during development and endosymbiosis was further characterized using RNAi. Reduction in Bm-cpl-3 and Bm-cpl-6 transcript levels was accompanied by hindered microfilarial development and release, and reduced Wolbachia DNA levels, making these enzymes strong drug target candidates.

  12. Potential involvement of Brugia malayi cysteine proteases in the maintenance of the endosymbiotic relationship with Wolbachia

    PubMed Central

    Lustigman, Sara; Melnikow, Elena; Anand, Setty Balakrishnan; Contreras, Aroha; Nandi, Vijay; Liu, Jing; Bell, Aaron; Unnasch, Thomas R.; Rogers, Mathew B.; Ghedin, Elodie

    2014-01-01

    Brugia malayi, a parasitic nematode that causes lymphatic filariasis, harbors endosymbiotic intracellular bacteria, Wolbachia, that are required for the development and reproduction of the worm. The essential nature of this endosymbiosis led to the development of anti-Wolbachia chemotherapeutic approaches for the treatment of human filarial infections. Our study is aimed at identifying specific proteins that play a critical role in this endosymbiotic relationship leading to the identification of potential targets in the adult worms. Filarial cysteine proteases are known to be involved in molting and embryogenesis, processes shown to also be Wolbachia dependent. Based on the observation that cysteine protease transcripts are differentially regulated in response to tetracycline treatment, we focused on defining their role in symbiosis. We observe a bimodal regulation pattern of transcripts encoding cysteine proteases when in vitro tetracycline treated worms were examined. Using tetracycline-treated infertile female worms and purified embryos we established that the first peak of the bimodal pattern corresponds to embryonic transcripts while the second takes place within the hypodermis of the adult worms. Localization studies of the native proteins corresponding to Bm-cpl-3 and Bm-cpl-6 indicate that they are present in the area surrounding Wolbachia, and, in some cases, the proteins appear localized within the bacteria. Both proteins were also found in the inner bodies of microfilariae. The possible role of these cysteine proteases during development and endosymbiosis was further characterized using RNAi. Reduction in Bm-cpl-3 and Bm-cpl-6 transcript levels was accompanied by hindered microfilarial development and release, and reduced Wolbachia DNA levels, making these enzymes strong drug target candidates. PMID:25516837

  13. A Hydroalcoholic Extract from Paullinia pinnata L. Roots Exerts Anthelmintic Activity against Free-Living and Parasitic Nematodes.

    PubMed

    Spiegler, Verena; Liebau, Eva; Peppler, Carolin; Raue, Katharina; Werne, Steffen; Strube, Christina; Heckendorn, Felix; Agyare, Christian; Stark, Timo; Hofmann, Thomas; Hensel, Andreas

    2016-08-01

    Paullinia pinnata is a medicinal plant traditionally used in West Africa against a wide range of diseases including soil-transmitted helminthiases. In this study, a hydroethanolic root extract was investigated for its phytochemical composition and in vitro activity against the free-living nematode Caenorhabditis elegans as well as the larval stages of the parasitic helminths Ancylostoma caninum, Haemonchus contortus, Toxocara cati, and Trichuris vulpis.LC-MS analysis of the ethanol-water (1 : 1) extract revealed epicatechin and different A-type linked oligomeric and polymeric procyanidins as the predominant compounds.Within an in vitro mortality assay, the extract showed a lethal activity against T. cati (LC50 of 112 µg/mL), T. vulpis (LC50 of 17 µg/mL), and C. elegans (LC50 2.5 of mg/mL), but not against A. caninum. Additionally, effects on egg hatching and larval migration of H. contortus were investigated, but no inhibitory activity was observed.Overall, these findings rationalize the traditional use of the root extract from P. pinnata as an anthelmintic remedy and provide insight into the phytochemical composition of the extract. PMID:27286336

  14. Combinations of Biocontrol Agents for Management of Plant-Parasitic Nematodes and Soilborne Plant-Pathogenic Fungi

    PubMed Central

    Meyer, Susan L. F.; Roberts, Daniel P.

    2002-01-01

    Numerous microbes are antagonistic to plant-parasitic nematodes and soilborne plant-pathogenic fungi, but few of these organisms are commercially available for management of these pathogens. Inconsistent performance of applied biocontrol agents has proven to be a primary obstacle to the development of successful commercial products. One of the strategies for overcoming inconsistent performance is to combine the disease-suppressive activity of two (or more) beneficial microbes in a biocontrol preparation. Such combinations have potential for more extensive colonization of the rhizosphere, more consistent expression of beneficial traits under a broad range of soil conditions, and antagonism to a larger number of plant pests or pathogens than strains applied individually. Conversely, microbes applied in combination also may have antagonistic interactions with each other. Increased, decreased, and unaltered suppression of the target pathogen or pest has been observed when biocontrol microbes have been applied in combination. Unfortunately, the ecological basis for increased or decreased suppression has not been determined in many cases and needs further consideration. The complexity of interactions involved in the application of multiple organisms for biological control has slowed progress toward development of successful formulations. However, this approach has potential for overcoming some of the efficacy problems that occur with application of individual biocontrol agents. PMID:19265899

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

    PubMed Central

    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. PMID:26635750

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

    PubMed

    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. PMID:26635750

  17. A Hydroalcoholic Extract from Paullinia pinnata L. Roots Exerts Anthelmintic Activity against Free-Living and Parasitic Nematodes.

    PubMed

    Spiegler, Verena; Liebau, Eva; Peppler, Carolin; Raue, Katharina; Werne, Steffen; Strube, Christina; Heckendorn, Felix; Agyare, Christian; Stark, Timo; Hofmann, Thomas; Hensel, Andreas

    2016-08-01

    Paullinia pinnata is a medicinal plant traditionally used in West Africa against a wide range of diseases including soil-transmitted helminthiases. In this study, a hydroethanolic root extract was investigated for its phytochemical composition and in vitro activity against the free-living nematode Caenorhabditis elegans as well as the larval stages of the parasitic helminths Ancylostoma caninum, Haemonchus contortus, Toxocara cati, and Trichuris vulpis.LC-MS analysis of the ethanol-water (1 : 1) extract revealed epicatechin and different A-type linked oligomeric and polymeric procyanidins as the predominant compounds.Within an in vitro mortality assay, the extract showed a lethal activity against T. cati (LC50 of 112 µg/mL), T. vulpis (LC50 of 17 µg/mL), and C. elegans (LC50 2.5 of mg/mL), but not against A. caninum. Additionally, effects on egg hatching and larval migration of H. contortus were investigated, but no inhibitory activity was observed.Overall, these findings rationalize the traditional use of the root extract from P. pinnata as an anthelmintic remedy and provide insight into the phytochemical composition of the extract.

  18. Taxonomic status of Syngamus nematodes parasitizing passeriform hosts from Central Europe: Morphological, morphometric and molecular identification.

    PubMed

    Kanarek, Gerard; Zaleśny, Grzegorz; Sitko, Jiljí; Rząd, Izabella

    2016-10-01

    The systematic position and validity of species within genus Syngamus have always been controversial. In this present work, we evaluated the taxonomic status and phylogenetic relationships between three species of Syngamus nematodes (Syngamus trachea, Syngamus taiga and Syngamus merulae) and one taxa, determined only to the generic level, collected from respiratory tracts of passeriform hosts from Central Europe using newly obtained sequences of 2 nuclear markers (internal transcribed spacers 1 and 2 [ITS1, ITS2]) and a fragment of mitochondrial cytochrome oxidase I [COI] gene. Our results clearly showed that S. trachea, S. taiga and S. merulae are valid, molecularly and morphologically distinct species. Moreover, molecular analysis of adult female of Syngamus sp. collected from tracheae of the European robin Erithacus rubecula clearly indicate that these comprise separate species. In the derived phylogeny, the Syngamus clade is divided into two sub-clades: one comprised Syngamus species with a characteristic, well-developed cuticular collar around the oral opening (S. trachea and S. taiga) and a second that groups taxa without or with rudimentary collar (S. merulae and currently sequenced Syngamus sp. from Erithacus rubecula). These results clearly suggest that the degree of collar development (well-developed vs. rudimentary/absent) may be an important phylogenetic feature for determining the structure of the genus Syngamus on subgeneric level. Additionally, our results support historical division of the genus Syngamus into two subgenera S. (Syngamus) and S. (Ornithogamus).

  19. Taxonomic status of Syngamus nematodes parasitizing passeriform hosts from Central Europe: Morphological, morphometric and molecular identification.

    PubMed

    Kanarek, Gerard; Zaleśny, Grzegorz; Sitko, Jiljí; Rząd, Izabella

    2016-10-01

    The systematic position and validity of species within genus Syngamus have always been controversial. In this present work, we evaluated the taxonomic status and phylogenetic relationships between three species of Syngamus nematodes (Syngamus trachea, Syngamus taiga and Syngamus merulae) and one taxa, determined only to the generic level, collected from respiratory tracts of passeriform hosts from Central Europe using newly obtained sequences of 2 nuclear markers (internal transcribed spacers 1 and 2 [ITS1, ITS2]) and a fragment of mitochondrial cytochrome oxidase I [COI] gene. Our results clearly showed that S. trachea, S. taiga and S. merulae are valid, molecularly and morphologically distinct species. Moreover, molecular analysis of adult female of Syngamus sp. collected from tracheae of the European robin Erithacus rubecula clearly indicate that these comprise separate species. In the derived phylogeny, the Syngamus clade is divided into two sub-clades: one comprised Syngamus species with a characteristic, well-developed cuticular collar around the oral opening (S. trachea and S. taiga) and a second that groups taxa without or with rudimentary collar (S. merulae and currently sequenced Syngamus sp. from Erithacus rubecula). These results clearly suggest that the degree of collar development (well-developed vs. rudimentary/absent) may be an important phylogenetic feature for determining the structure of the genus Syngamus on subgeneric level. Additionally, our results support historical division of the genus Syngamus into two subgenera S. (Syngamus) and S. (Ornithogamus). PMID:27353021

  20. Meloidogyne platani n. sp. (Meloidogynidae), a Root-knot Nematode Parasitizing American Sycamore.

    PubMed

    Hirschmann, H

    1982-01-01

    Meloidogyne platani n. sp. is described and illustrated from specimens obtained from roots of American sycamore, Platanus occidentalis, in Virginia. This new species shows certain similarities with M. arenaria but differs from it by a number of distinctive characters. The perineal pattern of females is rounded with fine, wavy to zig-zag striae and raised, convoluted striae in the inner lateral line regions. The stylet of females is 16.5 mum long with large, rounded stylet knobs set off from the shaft. Males have a low head cap and smooth head region. The styler length is 22.0 mum, and the stylet knobs are rounded and set off from the shaft. Mean second-stage juvenile length is 443.0 mum, and stylet length is 12.2 mum. The head region of juveniles is not annulated, and the tail has a definite terminus. This nematode causes severe galling and reproduces well on sycamore. Other good hosts include white ash and tobacco cv. NC 95. M. platani n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of approximately 45 (2n).

  1. An annotated catalogue of the ascaridoid nematode parasites of Chinese vertebrates.

    PubMed

    Li, Liang; Gibson, David I; Zhang, Lu-Ping

    2016-01-01

    A catalogue, based on both examined specimens and the published literature, of all the ascaridoid nematodes recorded in China is presented. A total of 95 recognised species, representing 26 genera in five families, are reported. Detailed information on the type-host, type-locality, original reference, synonyms, annotated subsequent references of taxonomic importance, other host records, site of infection, location of type-specimens and distribution are listed for each recognised species. Additional comments on the taxonomic status of some species are also given. Moreover, some nomenclatural changes are proposed: (i) Toxascaris selenarctis Wang, 1965 and T. ailuri Wu, He & Hu, 1987 are placed in synonymy with Baylisascaris transfuga (Rudolphi, 1819); (ii) Raphidascaris lophii Wang & Wu, 1991 is a secondary homonym of R. lophii (Wu, 1949) and a replacement name, R. wangi nom. nov., is proposed for the former species; (iii) Aliascaris aetoplatea Luo, 2001 is transferred to Terranova Leiper & Atkinson, 1914, as T. aetoplatea (Luo, 2001) n. comb., and should be considered a species inquirenda; (iv) Ophidascaris orientalis (Wang, 1965) is resurrected as a valid species; (v) Phocascaris longispiculum Wang & Wu, 1991 and Ophidascaris agkistrodontis Wang, 1979 are treated as incertae sedis; and (vi) Hysterothylacium sauridae Li, Xu & Zhang, 2008 is listed as a nomen nudum. PMID:26739284

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

    PubMed

    Uni, S; Bain, O; Agatsuma, T; Katsumi, A; Baba, M; Yanai, T; Takaoka, H

    2006-09-01

    A new onchocercid species, Loxodontofilaria caprini n. sp. (Filarioidea: Nematoda), found in subcutaneous tissues of 37 (33%) of 112 serows (Noemorhedus 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 loxodontofiloria: 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. PMID:17007210

  3. WormAssay: A Novel Computer Application for Whole-Plate Motion-based Screening of Macroscopic Parasites

    PubMed Central

    Marcellino, Chris; Gut, Jiri; Lim, K. C.; Singh, Rahul; McKerrow, James; Sakanari, Judy

    2012-01-01

    Lymphatic filariasis is caused by filarial nematode parasites, including Brugia malayi. Adult worms live in the lymphatic system and cause a strong immune reaction that leads to the obstruction of lymph vessels and swelling of the extremities. Chronic disease leads to the painful and disfiguring condition known as elephantiasis. Current drug therapy is effective against the microfilariae (larval stage) of the parasite, but no drugs are effective against the adult worms. One of the major stumbling blocks toward developing effective macrofilaricides to kill the adult worms is the lack of a high throughput screening method for candidate drugs. Current methods utilize systems that measure one well at a time and are time consuming and often expensive. We have developed a low-cost and simple visual imaging system to automate and quantify screening entire plates based on parasite movement. This system can be applied to the study of many macroparasites as well as other macroscopic organisms. PMID:22303493

  4. Effect of Tropical Rotation Crops on Meloidogyne incognita and Other Plant-Parasitic Nematodes.

    PubMed

    McSorley, R; Dickson, D W

    1995-12-01

    In a field experiment conducted on sandy soil in Florida during the 1993 season, rotation crops of castor (Ricinus communis), velvetbean (Mucuna deeringina), 'Mississippi Silver' cowpea (Vigna unguiculata), American jointvetch (Aeschynomene americana), 'Dehapine 51' cotton (Gossypium hirsutum), and 'SX-17' sorghum-sudangrass (Sorghum bicolor x S. sudanense) were effective in maintaining low population densities (<12/100 cm(3) soil) of Meloidogyne incognita race 1, whereas high population densities (>450/100 cm(3) soil) resulted after 'Clemson Spineless' okra (Hibiscus esculentus) and 'Kirby' soybean (Glycine max). Following a winter cover crop of rye (Secale cereale), densities of M. incognita following the six most effective rotation crops (1993 season) remained relatively low (nematode pests as well.

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

    PubMed

    Peña-Espinoza, Miguel; Thamsborg, Stig M; Desrues, Olivier; Hansen, Tina V A; Enemark, Heidi L

    2016-09-01

    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, O. ostertagi counts were significantly reduced in CHI1 by 60% (geometric mean; P < 0·01), whereas C. oncophora burdens were unaffected (P = 0·12). In Exp. 2, FEC were markedly lowered in CHI2 from D22 p.i onwards (P < 0·01). Ostertagia ostertagi adult burdens were significantly reduced in CHI2 by 66% (P < 0·001). Sesquiterpene lactones were identified only in chicory (fresh/silage). Chicory shows promise as an anti-Ostertagia feed for cattle and further studies should investigate its on-farm use. PMID:27173405

  6. RNA-Seq Based Identification of Candidate Parasitism Genes of Cereal Cyst Nematode (Heterodera avenae) during Incompatible Infection to Aegilops variabilis

    PubMed Central

    Zheng, Minghui; Long, Hai; Zhao, Yun; Li, Lin; Xu, Delin; Zhang, Haili; Liu, Feng; Deng, Guangbing; Pan, Zhifen; Yu, Maoqun

    2015-01-01

    One of the reasons for the progressive yield decline observed in cereals production is the rapid build-up of populations of the cereal cyst nematode (CCN, Heterodera avenae). These nematodes secrete so-call effectors into their host plant to suppress the plant defense responses, alter plant signaling pathways and then induce the formation of syncytium after infection. However, little is known about its molecular mechanism and parasitism during incompatible infection. To gain insight into its repertoire of parasitism genes, we investigated the transcriptome of the early parasitic second-stage (30 hours, 3 days and 9 days post infection) juveniles of the CCN as well as the CCN infected tissue of the host Aegilops variabilis by Illumina sequencing. Among all assembled unigenes, 681 putative genes of parasitic nematode were found, in which 56 putative effectors were identified, including novel pioneer genes and genes corresponding to previously reported effectors. All the 681 CCN unigenes were mapped to 229 GO terms and 200 KEGG pathways, including growth, development and several stimulus-related signaling pathways. Sixteen clusters were involved in the CCN unigene expression atlas at the early stages during infection process, and three of which were significantly gene-enriched. Besides, the protein-protein interaction network analysis revealed 35 node unigenes which may play an important role in the plant-CCN interaction. Moreover, in a comparison of differentially expressed genes between the pre-parasitic juveniles and the early parasitic juveniles, we found that hydrolase activity was up-regulated in pre J2s whereas binding activity was upregulated in infective J2s. RT-qPCR analysis on some selected genes showed detectable expression, indicating possible secretion of the proteins and putative role in infection. This study provided better insights into the incompatible interaction between H. avenae and the host plant Ae. varabilis. Moreover, RNAi targets with

  7. RNA-Seq Based Identification of Candidate Parasitism Genes of Cereal Cyst Nematode (Heterodera avenae) during Incompatible Infection to Aegilops variabilis.

    PubMed

    Zheng, Minghui; Long, Hai; Zhao, Yun; Li, Lin; Xu, Delin; Zhang, Haili; Liu, Feng; Deng, Guangbing; Pan, Zhifen; Yu, Maoqun

    2015-01-01

    One of the reasons for the progressive yield decline observed in cereals production is the rapid build-up of populations of the cereal cyst nematode (CCN, Heterodera avenae). These nematodes secrete so-call effectors into their host plant to suppress the plant defense responses, alter plant signaling pathways and then induce the formation of syncytium after infection. However, little is known about its molecular mechanism and parasitism during incompatible infection. To gain insight into its repertoire of parasitism genes, we investigated the transcriptome of the early parasitic second-stage (30 hours, 3 days and 9 days post infection) juveniles of the CCN as well as the CCN infected tissue of the host Aegilops variabilis by Illumina sequencing. Among all assembled unigenes, 681 putative genes of parasitic nematode were found, in which 56 putative effectors were identified, including novel pioneer genes and genes corresponding to previously reported effectors. All the 681 CCN unigenes were mapped to 229 GO terms and 200 KEGG pathways, including growth, development and several stimulus-related signaling pathways. Sixteen clusters were involved in the CCN unigene expression atlas at the early stages during infection process, and three of which were significantly gene-enriched. Besides, the protein-protein interaction network analysis revealed 35 node unigenes which may play an important role in the plant-CCN interaction. Moreover, in a comparison of differentially expressed genes between the pre-parasitic juveniles and the early parasitic juveniles, we found that hydrolase activity was up-regulated in pre J2s whereas binding activity was upregulated in infective J2s. RT-qPCR analysis on some selected genes showed detectable expression, indicating possible secretion of the proteins and putative role in infection. This study provided better insights into the incompatible interaction between H. avenae and the host plant Ae. varabilis. Moreover, RNAi targets with

  8. Molecular characterization of the reniform nematode C-type lectin gene family reveals a likely role in mitigating environmental stresses during plant parasitism.

    PubMed

    Ganji, Satish; Jenkins, Johnie N; Wubben, Martin J

    2014-03-10

    The reniform nematode, Rotylenchulus reniformis, is a damaging semi-endoparasitic pathogen of more than 300 plant species. Transcriptome sequencing of R. reniformis parasitic females revealed an enrichment for sequences homologous to C-type lectins (CTLs), an evolutionarily ancient family of Ca(+2)-dependent carbohydrate-binding proteins that are involved in the innate immune response. To gain further insight as to the potential role of CTLs in facilitating plant parasitism by R. reniformis, we performed a comprehensive assessment of the CTL gene family. 5'- and 3'-RACE experiments identified a total of 11 R. reniformis CTL transcripts (Rr-ctl-1 through Rr-ctl-11) that ranged in length from 1083 to 1,194 bp and showed 93-99% identity with one another. An alignment of cDNA and genomic sequences revealed three introns with the first intron residing within the 5'-untranslated region. BLAST analyses showed the closest homologs belonging to the parasitic nematodes Heligmosomoides polygyrus and Heterodera glycines. Rr-ctl-1, -2, and -3 were expressed throughout the R. reniformis life cycle; whereas, the remaining Rr-ctl genes showed life stage-specific expression. Quantitative real time RT-PCR determined that Rr-ctl transcripts were 839-fold higher in sedentary female nematodes than the next most abundant life stage. Predicted Rr-CTL peptides ranged from 301 to 338 amino acids long, possessed an N-terminal signal peptide for secretion, and contained a conserved CLECT domain, including the mannose-binding motifs EPN and EPD and the conserved WND motif that is required for binding Ca(+2). In addition, Rr-CTL peptides harbored repeats of a novel 17-mer motif within their C-terminus that showed similarity to motifs associated with bacterial ice nucleation proteins. In situ hybridization of Rr-ctl transcripts within sedentary females showed specific accumulation within the hypodermis of the body regions exposed to the soil environment; those structures embedded within the

  9. Coynema gen. n., a new genus of nematode (Thelastomatoidea, Hystrignathidae) parasites of Passalidae (Coleoptera) from Cuba

    PubMed Central

    Rodríguez, Jans Morffe; Rodríguez, Nayla García

    2011-01-01

    Abstract The new genus Coynema gen. n. is described as parasite of the two passalid beetles from Cuba: Passalus interstitialis Escholtz, 1829 (type host) and Passalus pertyi Kaup, 1869. Females are characterized by the shape of their cephalic end, cervical cuticle unarmed, a sub-cylindrical procorpus with its base abruptly dilated, fore region of intestine dilated as a sac-like structure, genital system didelphic-amphidelphic and eggs markedly ovoid and smooth-shelled. Males have a digestive system similar to females, tail sharply pointed, bearing a Y-like thickening of the dorsal cuticle. They also present a big, median, mammiform pre-cloacal papillae and a pair of small, sub-dorsal pre-cloacal papillae anterior to the cuticular thickening of the tail. PMID:21594137

  10. Galectins in the abdominal cavity of the conger eel Conger myriaster participate in the cellular encapsulation of parasitic nematodes by host cells.

    PubMed

    Nakamura, Osamu; Watanabe, Mizuki; Ogawa, Tomohisa; Muramoto, Koji; Ogawa, Kazuo; Tsutsui, Shigeyuki; Kamiya, Hisao

    2012-10-01

    Congerin is a proto-type galectin distributed on the skin and mucosal epithelia of the upper digestive tract of the Japanese conger eel Conger myriaster. It has at least 2 isotypes, namely, congerin I and II, and plays a role in bio-defense at the body surface. In the current study, we identified both isotypes in the peritoneal fluid and peritoneal cells of C. myriaster by western blot and mass spectrometry (MS)/MS analysis. Cucullanus nematodes parasitize the abdominal cavity of C. myriaster, and immunohistochemical analyses demonstrated that congerins can bind to both the body surface of the encapsulated nematodes and the encapsulating cells. Furthermore, adhesion of the peritoneal cells to Sepharose particles was greatly accelerated when the microspheres were coated with congerin. Indeed, this effect was significantly hampered by the addition of lactose. These results indicate that congerin participates in the cellular encapsulation of the Cucullanus nematode via the induction of cellular adhesion to the parasites depending on lectin-glycoside recognition.

  11. A comparison of two integrated approaches of controlling nematode parasites in small ruminants.

    PubMed

    Miller, J E; Burke, J M; Terrill, T H; Kearney, M T

    2011-06-10

    Control of gastrointestinal nematodes (GIN) in small ruminants in regions of the world where anthelmintic resistance is prevalent must rely on more than just chemical deworming strategies. The objective of this experiment was to compare two integrated treatment protocols for control of GIN (primarily Haemonchus contortus in this region) using anthelmintics, copper oxide wire particles (COWP) and FAMACHA(©), compared to traditional anthelmintic use only. Three separate trials were conducted on mature ewes, weaned goats, and weaned lambs in which three deworming management strategies were applied: 1) all animals were dewormed with levamisole at four week intervals (LEV), 2) individual animals were dewormed with moxidectin when scored≥4 (ewes) or ≥3 (kids and lambs) using FAMACHA(©) (FAM/MOX), 3) all animals were dewormed with moxidectin initially and again with COWP (2g) when group mean FEC exceeded 500 (ewes), 3000 (kids), or 1000 (lambs) eggs/g (MOX/COWP). In this final group, during periods between group treatments, individual animals were dewormed with albendazole and levamisole according to FAMACHA(©) score. Fecal egg counts (FEC) and blood packed cell volume (PCV) were determined every 7 days and body weight every 28 days for 30, 20, or 16 weeks in ewes, goats, and lambs, respectively. Efficacy of levamisole was 83.4-86.4%, efficacy of moxidectin was 93.5-100%, and efficacy of COWP was 10.8-98.1% among the three trials. The mean number of deworming treatments per animal that occurred for the LEV, FAM/MOX, and MOX/COWP groups, respectively, was 7.9, 0.6, and 2.5±0.4 (P<0.001) for ewes, 5.2, 1.6, and 3.4±0.3 (P<0.001) for goats, and 4.0, 1.7, and 3.6±0.2 (P<0.001) for lambs. Production (body weight of lambs weaned from ewes or final body weight of kids and lambs) was similar among management strategy groups for ewes and kids, but FAM/MOX lambs were lighter by the end of the trial (P<0.003). While more time and labor was required to use the FAMACHA

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

    PubMed

    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.

  13. Activity of Hydroxamic Acids from Secale cereale Against the Plant-Parasitic Nematodes Meloidogyne incognita and Xiphinema americanum.

    PubMed

    Zasada, I A; Meyer, S L F; Halbrendt, J M; Rice, C

    2005-10-01

    ABSTRACT Cyclic hydroxamic acids are secondary metabolites found in the family Poaceae and have been implicated in the allelopathy of rye (Secale cereale). The toxicity of these compounds against plant-parasitic nematodes is unknown. DIBOA (2,4-dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one), DIMBOA (2,4-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one), and their degradation products BOA (benzoxazolin-2(3H)-one) and MBOA (6-methoxy-benzoxazolin-2(3H)-one) were screened in vitro against Meloidogyne incognita second-stage juveniles (J2) and eggs and mixed-stages of Xiphinema americanum. Xiphinema americanum was more sensitive to DIBOA and DIMBOA than M. incognita J2, with a maximum apparent mortality of 96 and 92% compared to 73 and 72% at 90 mug/ml. Eggs of M. incognita were less sensitive to the hydroxamic acids than J2; only DIBOA resulted in a 50% reduction in egg hatch, with a lethal concentration (LC(50)) of 74 mug/ml compared to 21 mug/ml for J2. When M. incognita J2 were exposed to DIBOA for 48 h and the compound was removed and replaced with water, the LC(50) value increased from 21.0 to 40.7 mug/ml. MBOA was not toxic to X. americanum or M. incognita eggs, but was toxic to M. incognita J2, with LC(50) values of 44 and 20 mug/ml before and after the compound was removed and replaced with water. BOA was the least toxic hydroxamic acid tested; it did not reduce M. incognita egg hatch after 1 week of exposure or increase X. americanum mortality after 24 h of exposure. While in vitro studies provide a valuable starting point in determining the toxicity of the chemical component of rye, the relevance of the data to soil remains to be determined.

  14. Changes in cyclic nucleotides, locomotory behavior, and body length produced by novel endogenous neuropeptides in the parasitic nematode Ascaris suum.

    PubMed

    Reinitz, Catharine A; Pleva, Anthony E; Stretton, Antony O W

    2011-11-01

    Recent technical advances have rapidly advanced the discovery of novel peptides, as well as the transcripts that encode them, in the parasitic nematode Ascaris suum. Here we report that many of these novel peptides produce profound and varied effects on locomotory behavior and levels of cyclic nucleotides in A. suum. We investigated the effects of 31 endogenous neuropeptides encoded by transcripts afp-1, afp-2, afp-4, afp-6, afp-7, and afp-9-14 (afp: Ascaris FMRFamide-like Precursor protein) on cyclic nucleotide levels, body length and locomotory behavior. Worms were induced to generate anteriorly propagating waveforms, peptides were injected into the pseudocoelomic cavity, and changes in the specific activity (nmol/mg protein) of second messengers cAMP (3'5' cyclic adenosine monophosphate) and cGMP (3'5' cyclic guanosine monophosphate) were determined. Many of these neuropeptides changed the levels of cAMP (both increases and decreases were found), whereas few neuropeptides changed the level of cGMP. A subset of the peptides that lowered cAMP was investigated for effects on the locomotory waveform and on body length. Injection of AF19, or AF34 (afp-13), AF9 (afp-14), AF26 or AF41 (afp-11) caused immediate paralysis and cessation of propagating body waveforms. These neuropeptides also significantly increased body length. In contrast, injection of AF15 (afp-9) reduced the body length, and decreased the amplitude of waves in the body waveform. AF30 (afp-10) produced worms with tight ventral coils. Although injection of neuropeptides encoded by afp-1 (AF3, AF4, AF10 or AF13) produced an increased number of exaggerated body waves, there were no effects on either cAMP or cGMP. By injecting peptides into behaving A. suum, we have provided an initial screen of the effects of novel peptides on several behavioral and biochemical parameters.

  15. Lactic dehydrogenase virus infection enhances parasite egg production and inhibits eosinophil and mast cell responses in mice infected with the nematode Nippostrongylus brasiliensis.

    PubMed Central

    Morimoto, M; Yamada, M; Arizono, N; Hayashi, T

    1998-01-01

    The effects of lactic dehydrogenase virus (LDV) infection on the protective immune responses to the nematode Nippostrongylus brasiliensis were studied. Mice with chronic LDV infection showed significantly higher levels of parasite egg production than non-LDV-infected (control) mice after N. brasiliensis infection. Concurrent LDV infection also suppressed peripheral blood eosinophilia and the lung mastocytosis induced by this nematode. LDV infection showed higher expression levels of the interferon-gamma (IFN-gamma) mRNA in lymph nodes compared with control mice before N. brasiliensis infection. In addition, the IgG2a production in LDV-infected mice was higher than that in control mice before and after N. brasiliensis infection. These results suggest that LDV infection modulates protective immune responses against N. brasiliensis infection by the activation of T-helper type 1 cells. PMID:9659227

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

    PubMed

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

    2011-04-01

    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.

  17. Review of zoonotic parasites in medical and veterinary fields in the Republic of Korea.

    PubMed

    Youn, Heejeong

    2009-10-01

    Zoonotic parasites are animal parasites that can infect humans. The major zoonotic protozoa in the Republic of Korea are Babesia bovis, Chilomastix mesnili, Cryptosporidium parvum, Endolimax nana, Entamoeba coli, Entamoeba hitolytica, Giardia lamblia, Iodamoeba bütschlii, Pneumocystis carinii, Sarcocystis cruzi, and Toxoplasma gondii. The major zoonotic helminths in Korea include trematodes, cestodes, and nematodes. Trematodes are Clonorchis sinensis, Echinostoma hortense, Echinostoma spp., Fasciola hepatica, Heterophyes nocens, Metagonimus yokogawai, and Paragonimus westermani. Cestodes are Diphyllobothrium latum, Dipylidium caninum, Echinococcus granulosus, Hymenolepis nana, Raillietina tetragona, sparganum (Spirometra spp.), Taenia saginata, T. solium, and T. asiatica. Nematodes are Ancylostoma caninum, Brugia malayi, Capillaria hepatica, Dirofilaria immitis, Gnathostoma dololesi, Gnathostoma spinigerum, Loa loa, Onchocerca gibsoni, Strongyloides stercoralis, Thelazia callipaeda, Trichinella spiralis, Trichostrongylus orientalis, Trichuris trichiura, and Trichuris vulpis. The one arthropod is Sarcoptes scabiei. Many of these parasites have disappeared or were in decline after the 1990's. Since the late 1990's, the important zoonotic protozoa have been C. parvum, E. nana, E. coli, E. hitolytica, G. lamblia, I. buetschlii, P. carinii and T. gondii. The important zoonotic helminths have been C. sinensis, H. nocens, M. yokogawai, P. westermani, D. latum, T. asiatica, sparganum, B. malayi, T. orientalis, T. callipaeda and T. spiralis. However, outbreaks of these parasites are only in a few endemic areas. The outbreaks of Enterobius vermicularis and head lice, human parasites, have recently increased in the kindergartens and primary schools in the Republic of Korea. PMID:19885329

  18. Review of Zoonotic Parasites in Medical and Veterinary Fields in the Republic of Korea

    PubMed Central

    2009-01-01

    Zoonotic parasites are animal parasites that can infect humans. The major zoonotic protozoa in the Republic of Korea are Babesia bovis, Chilomastix mesnili, Cryptosporidium parvum, Endolimax nana, Entamoeba coli, Entamoeba hitolytica, Giardia lamblia, Iodamoeba bütschlii, Pneumocystis carinii, Sarcocystis cruzi, and Toxoplasma gondii. The major zoonotic helminths in Korea include trematodes, cestodes, and nematodes. Trematodes are Clonorchis sinensis, Echinostoma hortense, Echinostoma spp., Fasciola hepatica, Heterophyes nocens, Metagonimus yokogawai, and Paragonimus westermani. Cestodes are Diphyllobothrium latum, Dipylidium caninum, Echinococcus granulosus, Hymenolepis nana, Raillietina tetragona, sparganum (Spirometra spp.), Taenia saginata, T. solium, and T. asiatica. Nematodes are Ancylostoma caninum, Brugia malayi, Capillaria hepatica, Dirofilaria immitis, Gnathostoma dololesi, Gnathostoma spinigerum, Loa loa, Onchocerca gibsoni, Strongyloides stercoralis, Thelazia callipaeda, Trichinella spiralis, Trichostrongylus orientalis, Trichuris trichiura, and Trichuris vulpis. The one arthropod is Sarcoptes scabiei. Many of these parasites have disappeared or were in decline after the 1990's. Since the late 1990's, the important zoonotic protozoa have been C. parvum, E. nana, E. coli, E. hitolytica, G. lamblia, I. buetschlii, P. carinii and T. gondii. The important zoonotic helminths have been C. sinensis, H. nocens, M. yokogawai, P. westermani, D. latum, T. asiatica, sparganum, B. malayi, T. orientalis, T. callipaeda and T. spiralis. However, outbreaks of these parasites are only in a few endemic areas. The outbreaks of Enterobius vermicularis and head lice, human parasites, have recently increased in the kindergartens and primary schools in the Republic of Korea. PMID:19885329

  19. Intravascular filarial parasites inhibit platelet aggregation. Role of parasite-derived prostanoids.

    PubMed Central

    Liu, L X; Weller, P F

    1992-01-01

    The nematode parasites that cause human lymphatic filariasis survive for long periods in their vascular habitats despite continual exposure to host cells. Platelets do not adhere to blood-borne microfilariae, and thrombo-occlusive phenomena are not observed in patients with circulating microfilariae. We studied the ability of microfilariae to inhibit human platelet aggregation in vitro. Brugia malayi microfilariae incubated with human platelets caused dose-dependent inhibition of agonist-induced platelet aggregation, thromboxane generation, and serotonin release. As few as one microfilaria per 10(4) platelets completely inhibited aggregation of platelets induced by thrombin, collagen, arachidonic acid, or ionophore A23187. Microfilariae also inhibited aggregation of platelets in platelet-rich plasma stimulated by ADP, compound U46619, or platelet-activating factor. The inhibition required intimate proximity but not direct contact between parasites and platelets, and was mediated by parasite-derived soluble factors of low (less than 1,000 Mr) molecular weight that were labile in aqueous media and caused an elevation of platelet cAMP. Prior treatment of microfilariae with pharmacologic inhibitors of cyclooxygenase decreased both parasite release of prostacyclin and PGE2 and microfilarial inhibition of platelet aggregation. These results indicate that microfilariae inhibit platelet aggregation, via mechanisms that may include the elaboration of anti-aggregatory eicosanoids. Images PMID:1313445

  20. High-pressure freezing and freeze-substitution fixation reveal the ultrastructure of immature and mature spermatozoa of the plant-parasitic nematode Trichodorus similis (Nematoda; Triplonchida; Trichodoridae).

    PubMed

    Lak, Behnam; Yushin, Vladimir V; Slos, Dieter; Claeys, Myriam; Decraemer, Wilfrida; Bert, Wim

    2015-10-01

    The spermatozoa from testis and spermatheca of the plant-parasitic nematode Trichodorus similis Seinhorst, 1963 (Nematoda; Triplonchida; Trichodoridae) were studied with transmission electron microscopy (TEM), being the first study on spermatogenesis of a representative of the order Triplonchida and important to unravel nematode sperm evolution. Comprehensive results could only be obtained using high-pressure freezing (HPF) and freeze-substitution instead of chemical fixation, demonstrating the importance of cryo-fixation for nematode ultrastructural research. The spermatozoa from the testis (immature spermatozoa) are unpolarized cells covered by numerous filopodia. They contain a centrally-located nucleus without a nuclear envelope, surrounded by mitochondria. Specific fibrous bodies (FB) as long parallel bundles of filaments occupy the peripheral cytoplasm. No structures resembling membranous organelles (MO), as found in the sperm of many other nematodes, were observed in immature spermatozoa of T. similis. The spermatozoa from the uterus (mature or activated spermatozoa) are bipolar cells with an anterior pseudopod and posterior main cell body (MCB), which include a nucleus, mitochondria and MO appearing as large vesicles with finger-like invaginations of the outer cell membrane, or as large vesicles connected to the inner cell membrane. The peripheral MO open to the exterior via pores. In the mature sperm, neither FBs nor filopodia were observed. An important feature of T. similis spermatozoa is the late formation of MO; they first appear in mature spermatozoa. This pattern of MO formation is known for several other orders of the nematode class Enoplea: Enoplida, Mermithida, Dioctophymatida, Trichinellida but has never been observed in the class Chromadorea.

  1. Investigation of Acetylcholine Receptor Diversity in a Nematode Parasite Leads to Characterization of Tribendimidine- and Derquantel-Sensitive nAChRs

    PubMed Central

    Neveu, Cedric; Cabaret, Jacques; Cortet, Jacques; Peineau, Nicolas; Abongwa, Melanie; Courtot, Elise; Robertson, Alan P.; Martin, Richard J.

    2014-01-01

    Nicotinic acetylcholine receptors (nAChRs) of parasitic nematodes are required for body movement and are targets of important “classical” anthelmintics like levamisole and pyrantel, as well as “novel” anthelmintics like tribendimidine and derquantel. Four biophysical subtypes of nAChR have been observed electrophysiologically in body muscle of the nematode parasite Oesophagostomum dentatum, but their molecular basis was not understood. Additionally, loss of one of these subtypes (G 35 pS) was found to be associated with levamisole resistance. In the present study, we identified and expressed in Xenopus oocytes, four O. dentatum nAChR subunit genes, Ode-unc-38, Ode-unc-63, Ode-unc-29 and Ode-acr-8, to explore the origin of the receptor diversity. When different combinations of subunits were injected in Xenopus oocytes, we reconstituted and characterized four pharmacologically different types of nAChRs with different sensitivities to the cholinergic anthelmintics. Moreover, we demonstrate that the receptor diversity may be affected by the stoichiometric arrangement of the subunits. We show, for the first time, different combinations of subunits from a parasitic nematode that make up receptors sensitive to tribendimidine and derquantel. In addition, we report that the recombinant levamisole-sensitive receptor made up of Ode-UNC-29, Ode-UNC-63, Ode-UNC-38 and Ode-ACR-8 subunits has the same single-channel conductance, 35 pS and 2.4 ms mean open-time properties, as the levamisole-AChR (G35) subtype previously identified in vivo. These data highlight the flexible arrangements of the receptor subunits and their effects on sensitivity and resistance to the cholinergic anthelmintics; pyrantel, tribendimidine and/or derquantel may still be effective on levamisole-resistant worms. PMID:24497826

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

    PubMed

    Moravec, František; Taraschewski, Horst; Weyl, Olaf L F

    2013-07-01

    The little-known nematode species Heliconema africanum (Linstow, 1899) n. comb. (Physalopteridae) is redescribed based on light and scanning electron microscopical examinations of specimens collected from the stomach of the African longfin eel Anguilla mossambica (Peters) in the Nahoon River, Eastern Cape Province, South Africa. This species, previously misidentified as Heliconema longissimum (Ortlepp, 1922), is a common parasite of eels in South Africa. The systematic status of H. longissimum, a species originally described from unidentified Australian snakes, is unclear and probably several morphologically closely related species have been included under this name.

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

    PubMed

    Moravec, František; Taraschewski, Horst; Weyl, Olaf L F

    2013-07-01

    The little-known nematode species Heliconema africanum (Linstow, 1899) n. comb. (Physalopteridae) is redescribed based on light and scanning electron microscopical examinations of specimens collected from the stomach of the African longfin eel Anguilla mossambica (Peters) in the Nahoon River, Eastern Cape Province, South Africa. This species, previously misidentified as Heliconema longissimum (Ortlepp, 1922), is a common parasite of eels in South Africa. The systematic status of H. longissimum, a species originally described from unidentified Australian snakes, is unclear and probably several morphologically closely related species have been included under this name. PMID:23793500

  4. A Target Repurposing Approach Identifies N-myristoyltransferase as a New Candidate Drug Target in Filarial Nematodes

    PubMed Central

    Villemaine, Estelle; Poole, Catherine B.; Chapman, Melissa S.; Pollastri, Michael P.; Wyatt, Paul G.; Carlow, Clotilde K. S.

    2014-01-01

    Myristoylation is a lipid modification involving the addition of a 14-carbon unsaturated fatty acid, myristic acid, to the N-terminal glycine of a subset of proteins, a modification that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in human cancers, and for infectious diseases caused by fungi, viruses and protozoan parasites. We purified Caenorhabditis elegans and Brugia malayi NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and peptide substrates. Biochemical and structural analyses both revealed that the nematode enzymes are canonical NMTs, sharing a high degree of conservation with protozoan NMT enzymes. Inhibitory compounds that target NMT in protozoan species inhibited the nematode NMTs with IC50 values of 2.5–10 nM, and were active against B. malayi microfilariae and adult worms at 12.5 µM and 50 µM respectively, and C. elegans (25 µM) in culture. RNA interference and gene deletion in C. elegans further showed that NMT is essential for nematode viability. The effects observed are likely due to disruption of the function of several downstream target proteins. Potential substrates of NMT in B. malayi are predicted using bioinformatic analysis. Our genetic and chemical studies highlight the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against nematode diseases including filariasis. PMID:25188325

  5. A target repurposing approach identifies N-myristoyltransferase as a new candidate drug target in filarial nematodes.

    PubMed

    Galvin, Brendan D; Li, Zhiru; Villemaine, Estelle; Poole, Catherine B; Chapman, Melissa S; Pollastri, Michael P; Wyatt, Paul G; Carlow, Clotilde K S

    2014-09-01

    Myristoylation is a lipid modification involving the addition of a 14-carbon unsaturated fatty acid, myristic acid, to the N-terminal glycine of a subset of proteins, a modification that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in human cancers, and for infectious diseases caused by fungi, viruses and protozoan parasites. We purified Caenorhabditis elegans and Brugia malayi NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and peptide substrates. Biochemical and structural analyses both revealed that the nematode enzymes are canonical NMTs, sharing a high degree of conservation with protozoan NMT enzymes. Inhibitory compounds that target NMT in protozoan species inhibited the nematode NMTs with IC50 values of 2.5-10 nM, and were active against B. malayi microfilariae and adult worms at 12.5 µM and 50 µM respectively, and C. elegans (25 µM) in culture. RNA interference and gene deletion in C. elegans further showed that NMT is essential for nematode viability. The effects observed are likely due to disruption of the function of several downstream target proteins. Potential substrates of NMT in B. malayi are predicted using bioinformatic analysis. Our genetic and chemical studies highlight the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against nematode diseases including filariasis.

  6. Yeast-Based High-Throughput Screens to Identify Novel Compounds Active against Brugia malayi

    PubMed Central

    Bilsland, Elizabeth; Bean, Daniel M.; Devaney, Eileen; Oliver, Stephen G.

    2016-01-01

    Background Lymphatic filariasis is caused by the parasitic worms Wuchereria bancrofti, Brugia malayi or B. timori, which are transmitted via the bites from infected mosquitoes. Once in the human body, the parasites develop into adult worms in the lymphatic vessels, causing severe damage and swelling of the affected tissues. According to the World Health Organization, over 1.2 billion people in 58 countries are at risk of contracting lymphatic filariasis. Very few drugs are available to treat patients infected with these parasites, and these have low efficacy against the adult stages of the worms, which can live for 7–15 years in the human body. The requirement for annual treatment increases the risk of drug-resistant worms emerging, making it imperative to develop new drugs against these devastating diseases. Methodology/Principal Findings We have developed a yeast-based, high-throughput screening system whereby essential yeast genes are replaced with their filarial or human counterparts. These strains are labeled with different fluorescent proteins to allow the simultaneous monitoring of strains with parasite or human genes in competition, and hence the identification of compounds that inhibit the parasite target without affecting its human ortholog. We constructed yeast strains expressing eight different Brugia malayi drug targets (as well as seven of their human counterparts), and performed medium-throughput drug screens for compounds that specifically inhibit the parasite enzymes. Using the Malaria Box collection (400 compounds), we identified nine filarial specific inhibitors and confirmed the antifilarial activity of five of these using in vitro assays against Brugia pahangi. Conclusions/Significance We were able to functionally complement yeast deletions with eight different Brugia malayi enzymes that represent potential drug targets. We demonstrated that our yeast-based screening platform is efficient in identifying compounds that can discriminate between

  7. Molecular epidemiology, phylogeny and evolution of the filarial nematode Wuchereria bancrofti.

    PubMed

    Small, Scott T; Tisch, Daniel J; Zimmerman, Peter A

    2014-12-01

    Wuchereria bancrofti (Wb) is the most widely distributed of the three nematodes known to cause lymphatic filariasis (LF), the other two being Brugia malayi and Brugia timori. Current tools available to monitor LF are limited to diagnostic tests targeting DNA repeats, filarial antigens, and anti-filarial antibodies. While these tools are useful for detection and surveillance, elimination programs have yet to take full advantage of molecular typing for inferring infection history, strain fingerprinting, and evolution. To date, molecular typing approaches have included whole mitochondrial genomes, genotyping, targeted sequencing, and random amplified polymorphic DNA (RAPDs). These studies have revealed much about Wb biology. For example, in one study in Papua New Guinea researchers identified 5 major strains that were widespread and many minor strains some of which exhibit geographic stratification. Genome data, while rare, has been utilized to reconstruct evolutionary relationships among taxa of the Onchocercidae (the clade of filarial nematodes) and identify gene synteny. Their phylogeny reveals that speciation from the common ancestor of both B. malayi and Wb occurred around 5-6 millions years ago with shared ancestry to other filarial nematodes as recent as 15 million years ago. These discoveries hold promise for gene discovery and identifying drug targets in species that are more amenable to in vivo experiments. Continued technological developments in whole genome sequencing and data analysis will likely replace many other forms of molecular typing, multiplying the amount of data available on population structure, genetic diversity, and phylogenetics. Once widely available, the addition of population genetic data from genomic studies should hasten the elimination of LF parasites like Wb. Infectious disease control programs have benefited greatly from population genetics data and recently from population genomics data. However, while there is currently a surplus

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

    PubMed Central

    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. PMID:27615321

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

    PubMed

    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. PMID:27615321

  10. Horizontal Gene Transfer from Bacteria Has Enabled the Plant-Parasitic Nematode Globodera pallida to Feed on Host-Derived Sucrose.

    PubMed

    Danchin, Etienne G J; Guzeeva, Elena A; Mantelin, Sophie; Berepiki, Adokiye; Jones, John T

    2016-06-01

    The evolution of plant-parasitic nematodes (PPN) is unusual in that these organisms have acquired a range of genes from bacteria via horizontal gene transfer (HGT). The proteins encoded by most of these genes are involved in metabolism of various components of the plant cell wall during invasion of the host. Recent genome sequencing projects for PPN have shown that Glycosyl Hydrolase Family 32 (GH32) sequences are present in several PPN species. These sequences are absent from almost all other animals. Here, we show that the GH32 sequences from an economically important cyst nematode species, Globodera pallida are functional invertases, are expressed during feeding and are restricted in expression to the nematode digestive system. These data are consistent with a role in metabolizing host-derived sucrose. In addition, a detailed phylogenetic analysis shows that the GH32 sequences from PPN and those present in some insect species have distinct bacterial origins and do not therefore derive from a gene present in the last common ancestor of ecdysozoan species. HGT has therefore played at least two critical roles in the evolution of PPN, enabling both invasion of the host and feeding on the main translocation carbohydrate of the plant. PMID:26915958

  11. Roles of Steroids in Nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The inability of nematodes to biosynthesize steroids de novo and the resulting dependence of parasitic nematodes upon their hosts have enhanced the importance of elucidating the metabolism of sterols and the hormonal and other functions of steroids in nematodes. Biochemical research has revealed th...

  12. Formicitylenchus oregonensis n. g., n. sp. (Allantonematidae: Nematoda), the first tylenchid parasite of ants, with a review of nematodes described from ants.

    PubMed

    Poinar, George

    2003-09-01

    The first tylenchid parasite of ants, Formicitylenchus oregonensis n. g., n. sp., is described from a queen carpenter ant Camponotus vicinus Mayr in Western Oregon, USA. The new genus is characterised by the excretory pore anterior to the nerve-ring and rounded tails in the free-living adults, a stylet bearing basal thickenings in the free-living female, a smaller stylet lacking basal thickenings in the male and a short, crenulate leptoderan bursa. The mature parasitic female is light yellow and ovoviviparous. F. oregonensis n. sp. is closely related to members of Metaparasitylenchus Wachek, 1955, with species parasitising beetles living under bark or in rotten wood, a habitat similar to that of carpenter ants. However, males of Metaparasitylenchus are characterised by a fairly long tail with a broad peloderan bursa. It is suggested that this case of tylenchid parasitism in ants is an example of environmental host selection. A review of the described nematode parasites of ants is presented. PMID:12975624

  13. [Trophic types of the nematodes].

    PubMed

    Kornobis, Franciszek Wojciech

    2008-01-01

    The aim of the article is to present trophic types (i.e non-systematic groups feeding on the same kind of food) of the nematodes. Seven trophic types (covering all known species) are described: (1) microbivores (nematodes feeding on unicellular microorganisms) with two examples: C. elegans and the nematodes of two families: Steinernematidae and Heterorhabditidae, (2) parasites of Vertebrates, (3) parasites of Invertebrates with example of the family Acugutturidae, (4) parasites of plants with two examples: Tylenchorhynchus dubius and Heterodera schachtii, (5) parasites of fungi, (6) predatory nematodes, (7) omnivores (nematodes feeding on different kinds of food). Basic information on the anatomy of the alimentary canal and feeding behaviour of the nematodes are also provided.

  14. Fast assembly of the mitochondrial genome of a plant parasitic nematode (Meloidogyne graminicola) using next generation sequencing.

    PubMed

    Besnard, Guillaume; Jühling, Frank; Chapuis, Élodie; Zedane, Loubab; Lhuillier, Émeline; Mateille, Thierry; Bellafiore, Stéphane

    2014-05-01

    Little is known about the variations of nematode mitogenomes (mtDNA). Sequencing a complete mtDNA using a PCR approach remains a challenge due to frequent genome reorganizations and low sequence similarities between divergent nematode lineages. Here, a genome skimming approach based on HiSeq sequencing (shotgun) was used to assemble de novo the first complete mtDNA sequence of a root-knot nematode (Meloidogyne graminicola). An AT-rich genome (84.3%) of 20,030 bp was obtained with a mean sequencing depth superior to 300. Thirty-six genes were identified with a semi-automated approach. A comparison with a gene map of the M. javanica mitochondrial genome indicates that the gene order is conserved within this nematode lineage. However, deep genome rearrangements were observed when comparing with other species of the superfamily Hoplolaimoidea. Repeat elements of 111 bp and 94 bp were found in a long non-coding region of 7.5 kb, as similarly reported in M. javanica and M. hapla. This study points out the power of next generation sequencing to produce complete mitochondrial genomes, even without a reference sequence, and possibly opening new avenues for species/race identification, phylogenetics and population genetics of nematodes.

  15. Exome and transcriptome sequencing of Aedes aegypti identifies a locus that confers resistance to Brugia malayi and alters the immune response.

    PubMed

    Juneja, Punita; Ariani, Cristina V; Ho, Yung Shwen; Akorli, Jewelna; Palmer, William J; Pain, Arnab; Jiggins, Francis M

    2015-03-01

    Many mosquito species are naturally polymorphic for their abilities to transmit parasites, a feature which is of great interest for controlling vector-borne disease. Aedes aegypti, the primary vector of dengue and yellow fever and a laboratory model for studying lymphatic filariasis, is genetically variable for its capacity to harbor the filarial nematode Brugia malayi. The genome of Ae. aegypti is large and repetitive, making genome resequencing difficult and expensive. We designed exome captures to target protein-coding regions of the genome, and used association mapping in a wild Kenyan population to identify a single, dominant, sex-linked locus underlying resistance. This falls in a region of the genome where a resistance locus was previously mapped in a line established in 1936, suggesting that this polymorphism has been maintained in the wild for the at least 80 years. We then crossed resistant and susceptible mosquitoes to place both alleles of the gene into a common genetic background, and used RNA-seq to measure the effect of this locus on gene expression. We found evidence for Toll, IMD, and JAK-STAT pathway activity in response to early stages of B. malayi infection when the parasites are beginning to die in the resistant genotype. We also found that resistant mosquitoes express anti-microbial peptides at the time of parasite-killing, and that this expression is suppressed in susceptible mosquitoes. Together, we have found that a single resistance locus leads to a higher immune response in resistant mosquitoes, and we identify genes in this region that may be responsible for this trait. PMID:25815506

  16. Exome and Transcriptome Sequencing of Aedes aegypti Identifies a Locus That Confers Resistance to Brugia malayi and Alters the Immune Response

    PubMed Central

    Juneja, Punita; Ariani, Cristina V.; Ho, Yung Shwen; Akorli, Jewelna; Palmer, William J.; Pain, Arnab; Jiggins, Francis M.

    2015-01-01

    Many mosquito species are naturally polymorphic for their abilities to transmit parasites, a feature which is of great interest for controlling vector-borne disease. Aedes aegypti, the primary vector of dengue and yellow fever and a laboratory model for studying lymphatic filariasis, is genetically variable for its capacity to harbor the filarial nematode Brugia malayi. The genome of Ae. aegypti is large and repetitive, making genome resequencing difficult and expensive. We designed exome captures to target protein-coding regions of the genome, and used association mapping in a wild Kenyan population to identify a single, dominant, sex-linked locus underlying resistance. This falls in a region of the genome where a resistance locus was previously mapped in a line established in 1936, suggesting that this polymorphism has been maintained in the wild for the at least 80 years. We then crossed resistant and susceptible mosquitoes to place both alleles of the gene into a common genetic background, and used RNA-seq to measure the effect of this locus on gene expression. We found evidence for Toll, IMD, and JAK-STAT pathway activity in response to early stages of B. malayi infection when the parasites are beginning to die in the resistant genotype. We also found that resistant mosquitoes express anti-microbial peptides at the time of parasite-killing, and that this expression is suppressed in susceptible mosquitoes. Together, we have found that a single resistance locus leads to a higher immune response in resistant mosquitoes, and we identify genes in this region that may be responsible for this trait. PMID:25815506

  17. Operational issues in the control of the vectors of Brugia.

    PubMed

    Chang, M S

    2002-12-01

    An estimated 13 million people in the Oriental Region have brugian filariasis. The filarial parasites that cause this disease exist in periodic and sub-periodic forms and are transmitted by four genera of mosquito: Anopheles, Mansonia and, less frequently, Coquillettidia and Ochlerotatus. In most endemic countries, control of the disease has been entirely based on chemotherapy, although house-spraying and use of insecticide-treated bednets can be quite effective against the vectors of nocturnally periodic Brugia malayi and B. timori. The vector-control methods that may be applied against the Mansonia mosquitoes that transmit the parasites causing sub-periodic brugian filariasis are reviewed here. Most of the conventional methods for controlling the immature, aquatic stages of mosquitoes have proved unsatisfactory against Mansonia. The reason is that, unlike the those of other genera, the larvae and pupae of Mansonia spp. are relatively immobile and obtain air not at the water surface but from the underwater roots, stems and leaves of floating plants to which the larvae and pupae attach. Removal of host plants can be very effective in reducing Mansonia productivity, whereas large-scale use of herbicides is restricted by the potential adverse effects on the ecosystem. Environmental management in water-development projects remains the best option.

  18. [Parasite nematodes from Dusycion griseus (Gray, 1837), D. culpaeus (Molina, 1782) and Conepatus chinga (Molina, 1782) (Mammalia:Carnivora) in Neuquén, Argentina. Systematics and ecology].

    PubMed

    Stein, M; Suriano, D M; Novaro, A J

    1994-01-01

    Four nematode species (Physaloptera clausa Rudolphi, 1819; Ph. maxillaris Molin, 1860; Protospirura numidica criceticola Quentin, Karimi and Rodrigues De Almeida, 1968; Toxascaris leonina (Von Linstow, 1902) were collected from D. griseus, D. culpaeus and C. chinga in Neuquen Province, Argentina. These hosts were captured from April to August in 1990 and 1991. Ph. clausa and Ph. maxillaris ar redescribed. The systematic position of Ph. clausa is discussed and the authors conclude that this species could be considered the type species of the genus. The possibility that D. griseus and D. culpaeus could be the accidental hosts for P. n. criceticola is discussed. Prevalence, mean intensity and frequency of each species are given. These parameters were related with the diets of the hosts and the parasite life cycles. There was no relationship between parasitic burden of each host and their nutritional condition (Kendall Tau Test). Significant differences exist among the diet of each host and among prevalence values of each parasite species (Homogeneity Test SYSTAT Program).

  19. Vittatidera zeaphila (Nematoda: Heteroderidae), a new genus and species of cyst nematode parasitic on corn (Zea mays)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new genus and species of cyst nematode, Vittatidera zeaphila, is described from Tennessee. The new genus is superficially similar to Cactodera but is distinguished from other cyst-forming taxa in having a persistent lateral field in females and cysts, persistent vulval lips covering a circumfenes...

  20. Effects of the integration of sunn hemp and soil solarization on plant-parasitic and free-living nematodes.

    PubMed

    Marahatta, Sharadchandra P; Wang, Koon-Hui; Sipes, Brent S; Hooks, Cerruti R R

    2012-03-01

    Sunn hemp (SH), Crotolaria juncea, is known to suppress Rotylenchulus reniformis and weeds while enhancing free-living nematodes involved in nutrient cycling. Field trials were conducted in 2009 (Trial I) and 2010 (Trial II) to examine if SH cover cropping could suppress R. reniformis and weeds while enhancing free-living nematodes if integrated with soil solarization (SOL). Cover cropping of SH, soil solarization, and SH followed by SOL (SHSOL) were compared to weedy fallow control (C). Rotylenchulus reniformis population was suppressed by SHSOL at the end of cover cropping or solarization period (Pi) in Trial I, but not in Trial II. However, SOL and SHSOL did not suppress R. reniformis compared to SH in either trial. SH enhanced abundance of bacterivores and suppressed the % herbivores only at Pi in Trial II. At termination of the experiment, SH resulted in a higher enrichment index indicating greater soil nutrient availability, and a higher structure index indicating a less disturbed nematode community compared to C. SOL suppressed bacterivores and fungivores only in Trial II but not in Trial I. On the other hand, SHSOL enhanced bacterivores and fungivores only at Pi in Trial I. Weeds were suppressed by SH, SOL and SHSOL throughout the experiment. SHSOL suppressed R. reniformis and enhanced free-living nematodes better than SOL, and suppressed weeds better than SH.

  1. Nematicides Increase Grain Yields in Spring Wheat Cultivars and Suppress Plant-Parasitic and Bacterial-Feeding Nematodes

    PubMed Central

    Kimpinski, J.; Martin, R. A.; Sturz, A. V.

    2005-01-01

    Grain yields of spring wheat (Triticum aestivum L. cvs. AC Barrie, AC Walton, AC Wilmot, Belvedere, Glenlea) in field plots over a 3-year period were increased (P < 0.001) by an average of 0.56 (25.1%) and 1.17 (52.5%) tonnes/ha in comparison to untreated check plots when aldicarb at 2.24 kg or fosthiazate at 13.5 a.i./ha, respectively, were broadcast and incorporated into the soil to suppress nematodes. The planned F test using orthogonal coefficients indicated that the mean response of grain yields to nematicide treatments of AC Barrie and Glenlea, which are grown primarily in the prairie provinces of Canada, was greater (48.5%) than the mean response of Belvedere, AC Walton, and AC Wilmot (33.7%), which are more common in the Maritime region of Canada (P < 0.001). Root lesion nematodes (primarily Pratylenchus penetrans) in wheat roots and in root zone soil at harvest were reduced by the nematicide applications (P < 0.001). Bacterial-feeding nematodes (primarily Diplogaster lheritieri (Maupas)) in root zone soil were also suppressed by fosthiazate (P < 0.01) but not by aldicarb. These data indicate that root lesion nematodes cause substantial yield losses in spring wheat in the Maritime region of Canada. PMID:19262893

  2. Parasites

    MedlinePlus

    ... CME and CNE for clinicians... Parasitic Disease and Malaria Strategic Priorities: 2015—2020... Cyclosporiasis: Most U.S. cases ... R S T U V W X Y Z Malaria An ancient disease that affects millions of people ...

  3. New reports and a redescription of Porrocaecum heteropterum (Diesing, 1851) (Ascarididae), a rare nematode parasitic in South American.threskiornithid birds1.

    PubMed

    Digiani, M C; Sutton, C A

    2001-05-01

    Porrocaecum heteropterum (Diesing, 1851) (Nematoda, Ascarididae) is reported parasitising the white-faced ibis Plegadis chihi and the black-faced ibis Theristicus melanopis melanopis (Ciconiiformes, Threskiornithidae) from the Provinces of Buenos Aires and Neuquén, Argentina. This nematode has been reported very few times in the literature, mainly from Brazilian threskiornithids, and there have been no new reports following a redescription of the species given in 1957. This paper provides new host and locality records for this rather rare species, as well as some additional morphological data, mainly based on SEM studies, which complement the previous descriptions. The scarce and sporadic records of this species seem to indicate not only a defined host-specificity towards threskiornithid birds but also that the acquisition of this parasite is possible only when certain ecological barriers, including food availability, feeding habits and environmental conditions, are surmounted.

  4. The effects of short-term feeding of fresh cassava (Manihot esculenta) foliage on gastrointestinal nematode parasite infections in goats in Cambodia.

    PubMed

    Seng, Sokerya; Waller, Peter J; Ledin, Inger; Höglund, Johan

    2007-06-01

    The antiparasitic effect of cassava (Manihot esculenta Crantz) was tested in goats artificially infected with gastrointestinal parasitic nematodes. Each experimental group consisted of 6 pen-fed goats kept on a slatted floor. The treatments compared were: 1) controls fed grass only, 2) cassava replaced grass for 3 weeks from the commencement of larval dosing period, and 3) cassava replaced grass for 3 weeks after the worm infection was patent. A total of 2000 mixed-species infective nematode larvae (L3) were administered to each goat in four doses of 500 L3/day, commencing 5 weeks after removal of previously acquired infections with ivermectin. The faecal egg counts (FEC) reduced in both cassava fed groups during the time of feeding, compared to the controls. Although, FEC increased differently with time (P < 0.05), total adult worm burdens at slaughter (week 15) were not different between the treatment groups. No differences in live weight gain, or packed cell volume, between treatments were found. Whilst these results show limited evidence of an anthelmintic effect of cassava in the diet, they do suggest that feeding, or supplementation, of cassava over an extended period may prove beneficial.

  5. A sampling of factors relative to the epidemiology of gastrointestinal nematode parasites of cattle in the United States.

    PubMed

    Yazwinski, Thomas A; Tucker, Chris A

    2006-11-01

    Gastrointestinal nematodosis of cattle is a parasitic condition resulting from an immense and seemingly forever-expanding array of factors. Countless determinants influence the incidence and severity of the species-specific infections that occur in cattle, determinants that affect the free-living or environmental stages of the parasites and the parasitic stages. The vast majority of animals have a subclinical or economic level of parasitism undetectable to the eye but quantified more accurately by treatment-induced improved performance (e.g., feed efficiency, nitrogen balance, weight gain, milk production). Unfortunately, the results of treatment (effectiveness and improved animal performance) sometimes can be as varied as the parasitisms that are being treated. PMID:17071350

  6. Targeting Lysine Deacetylases (KDACs) in Parasites

    PubMed Central

    Wang, Qi; Rosa, Bruce A.; Nare, Bakela; Powell, Kerrie; Valente, Sergio; Rotili, Dante; Mai, Antonello; Marshall, Garland R.; Mitreva, Makedonka

    2015-01-01

    Due to an increasing problem of drug resistance among almost all parasites species ranging from protists to worms, there is an urgent need to explore new drug targets and their inhibitors to provide new and effective parasitic therapeutics. In this regard, there is growing interest in exploring known drug leads of human epigenetic enzymes as potential starting points to develop novel treatments for parasitic diseases. This approach of repurposing (starting with validated targets and inhibitors) is quite attractive since it has the potential to reduce the expense of drug development and accelerate the process of developing novel drug candidates for parasite control. Lysine deacetylases (KDACs) are among the most studied epigenetic drug targets of humans, and a broad range of small-molecule inhibitors for these enzymes have been reported. In this work, we identify the KDAC protein families in representative species across important classes of parasites, screen a compound library of 23 hydroxamate- or benzamide-based small molecules KDAC inhibitors, and report their activities against a range of parasitic species, including the pathogen of malaria (Plasmodium falciparum), kinetoplastids (Trypanosoma brucei and Leishmania donovani), and nematodes (Brugia malayi, Dirofilaria immitis and Haemonchus contortus). Compound activity against parasites is compared to that observed against the mammalian cell line (L929 mouse fibroblast) in order to determine potential parasite-versus-host selectivity). The compounds showed nanomolar to sub-nanomolar potency against various parasites, and some selectivity was observed within the small panel of compounds tested. The possible binding modes of the active compounds at the different protein target sites within different species were explored by docking to homology models to help guide the discovery of more selective, parasite-specific inhibitors. This current work supports previous studies that explored the use of KDAC inhibitors in

  7. Targeting Lysine Deacetylases (KDACs) in Parasites.

    PubMed

    Wang, Qi; Rosa, Bruce A; Nare, Bakela; Powell, Kerrie; Valente, Sergio; Rotili, Dante; Mai, Antonello; Marshall, Garland R; Mitreva, Makedonka

    2015-01-01

    Due to an increasing problem of drug resistance among almost all parasites species ranging from protists to worms, there is an urgent need to explore new drug targets and their inhibitors to provide new and effective parasitic therapeutics. In this regard, there is growing interest in exploring known drug leads of human epigenetic enzymes as potential starting points to develop novel treatments for parasitic diseases. This approach of repurposing (starting with validated targets and inhibitors) is quite attractive since it has the potential to reduce the expense of drug development and accelerate the process of developing novel drug candidates for parasite control. Lysine deacetylases (KDACs) are among the most studied epigenetic drug targets of humans, and a broad range of small-molecule inhibitors for these enzymes have been reported. In this work, we identify the KDAC protein families in representative species across important classes of parasites, screen a compound library of 23 hydroxamate- or benzamide-based small molecules KDAC inhibitors, and report their activities against a range of parasitic species, including the pathogen of malaria (Plasmodium falciparum), kinetoplastids (Trypanosoma brucei and Leishmania donovani), and nematodes (Brugia malayi, Dirofilaria immitis and Haemonchus contortus). Compound activity against parasites is compared to that observed against the mammalian cell line (L929 mouse fibroblast) in order to determine potential parasite-versus-host selectivity). The compounds showed nanomolar to sub-nanomolar potency against various parasites, and some selectivity was observed within the small panel of compounds tested. The possible binding modes of the active compounds at the different protein target sites within different species were explored by docking to homology models to help guide the discovery of more selective, parasite-specific inhibitors. This current work supports previous studies that explored the use of KDAC inhibitors in

  8. 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?

    PubMed

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

    2012-05-01

    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. PMID:22169402

  9. Isolation and sequencing of a cDNA for an unusual hemoglobin from the parasitic nematode Pseudoterranova decipiens.

    PubMed Central

    Dixon, B; Walker, B; Kimmins, W; Pohajdak, B

    1991-01-01

    A cDNA clone encoding a 333-amino acid hemoglobin was isolated from the nematode Pseudoterranova decipiens. The protein contains an 18-amino acid hydrophobic signal sequence and has a calculated mass of 37.6 kDa in the mature form. The predicted protein reveals an internal duplication of a 154-amino acid domain (51% identity). Both domains have significant sequence homology to other primitive hemoglobins, in agreement with a duplication event. Hydrophobicity plots reveal identical strongly hydrophobic regions in each domain, which are potential heme binding sites. This confirms previous suggestions that nematode hemoglobins can have two heme groups per molecule. In addition, each domain contains several conserved histidine motifs that may serve as potential copper binding sites. This result provides further evidence that hemoglobins may have evolved from a primitive cytochrome-like molecule. Images PMID:2062843

  10. Tracking changes in life-history traits related to unnecessary virulence in a plant-parasitic nematode.

    PubMed

    Castagnone-Sereno, Philippe; Mulet, Karine; Iachia, Cathy

    2015-09-01

    Evaluating trade-offs in life-history traits of plant pathogens is essential to understand the evolution and epidemiology of diseases. In particular, virulence costs when the corresponding host resistance gene is lacking play a major role in the adaptive biology of pathogens and contribute to the maintenance of their genetic diversity. Here, we investigated whether life-history traits directly linked to the establishment of plant-nematode interactions, that is, ability to locate and move toward the roots of the host plant, and to invade roots and develop into mature females, are affected in Meloidogyne incognita lines virulent against the tomato Mi-1.2 resistance gene. Virulent and avirulent near-isogenic lines only differing in their capacity to reproduce or not on resistant tomatoes were compared in single inoculation or pairwise competition experiments. Data highlighted (1) a global lack of trade-off in traits associated with unnecessary virulence with respect to the nematode ability to successfully infest plant roots and (2) variability in these traits when the genetic background of the nematode is considered irrespective of its (a)virulence status. These data suggest that the variation detected here is independent from the adaptation of M. incognita to host resistance, but rather reflects some genetic polymorphism in this asexual organism. PMID:26380696

  11. Tracking changes in life-history traits related to unnecessary virulence in a plant-parasitic nematode

    PubMed Central

    Castagnone-Sereno, Philippe; Mulet, Karine; Iachia, Cathy

    2015-01-01

    Evaluating trade-offs in life-history traits of plant pathogens is essential to understand the evolution and epidemiology of diseases. In particular, virulence costs when the corresponding host resistance gene is lacking play a major role in the adaptive biology of pathogens and contribute to the maintenance of their genetic diversity. Here, we investigated whether life-history traits directly linked to the establishment of plant–nematode interactions, that is, ability to locate and move toward the roots of the host plant, and to invade roots and develop into mature females, are affected in Meloidogyne incognita lines virulent against the tomato Mi-1.2 resistance gene. Virulent and avirulent near-isogenic lines only differing in their capacity to reproduce or not on resistant tomatoes were compared in single inoculation or pairwise competition experiments. Data highlighted (1) a global lack of trade-off in traits associated with unnecessary virulence with respect to the nematode ability to successfully infest plant roots and (2) variability in these traits when the genetic background of the nematode is considered irrespective of its (a)virulence status. These data suggest that the variation detected here is independent from the adaptation of M. incognita to host resistance, but rather reflects some genetic polymorphism in this asexual organism. PMID:26380696

  12. Tracking changes in life-history traits related to unnecessary virulence in a plant-parasitic nematode.

    PubMed

    Castagnone-Sereno, Philippe; Mulet, Karine; Iachia, Cathy

    2015-09-01

    Evaluating trade-offs in life-history traits of plant pathogens is essential to understand the evolution and epidemiology of diseases. In particular, virulence costs when the corresponding host resistance gene is lacking play a major role in the adaptive biology of pathogens and contribute to the maintenance of their genetic diversity. Here, we investigated whether life-history traits directly linked to the establishment of plant-nematode interactions, that is, ability to locate and move toward the roots of the host plant, and to invade roots and develop into mature females, are affected in Meloidogyne incognita lines virulent against the tomato Mi-1.2 resistance gene. Virulent and avirulent near-isogenic lines only differing in their capacity to reproduce or not on resistant tomatoes were compared in single inoculation or pairwise competition experiments. Data highlighted (1) a global lack of trade-off in traits associated with unnecessary virulence with respect to the nematode ability to successfully infest plant roots and (2) variability in these traits when the genetic background of the nematode is considered irrespective of its (a)virulence status. These data suggest that the variation detected here is independent from the adaptation of M. incognita to host resistance, but rather reflects some genetic polymorphism in this asexual organism.

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

    PubMed

    Simbari, Fabio; McCaskill, Jana; Coakley, Gillian; Millar, Marissa; Maizels, Rick M; Fabriás, Gemma; Casas, Josefina; Buck, Amy H

    2016-01-01

    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 plasmalogens in some EVs

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

    PubMed Central

    Simbari, Fabio; McCaskill, Jana; Coakley, Gillian; Millar, Marissa; Maizels, Rick M.; Fabriás, Gemma; Casas, Josefina; Buck, Amy H.

    2016-01-01

    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 plasmalogens in some EVs

  15. How do humans affect wildlife nematodes?

    USGS Publications Warehouse

    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.

  16. How do humans affect wildlife nematodes?

    PubMed

    Weinstein, Sara B; Lafferty, Kevin D

    2015-05-01

    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.

  17. Host protective ASP-based vaccine against the parasitic nematode Ostertagia ostertagi triggers NK cell activation and mixed IgG1-IgG2 response.

    PubMed

    González-Hernández, Ana; Van Coppernolle, Stefanie; Borloo, Jimmy; Van Meulder, Frederik; Paerewijck, Oonagh; Peelaers, Iris; Leclercq, Georges; Claerebout, Edwin; Geldhof, Peter

    2016-01-01

    The mucus-dwelling parasite Ostertagia ostertagi is one of the most important gastrointestinal nematodes in cattle. Our group has previously demonstrated the protective capacity of a vaccine against this parasite based on a native activation-associated secreted protein ASP1 (nASP) in combination with the saponin adjuvant QuilA. The aim of the current study was to analyse the effect of both antigen and adjuvant on the cellular and humoral vaccine-induced immune responses by comparing the native ASP to a recombinant version expressed in Pichia pastoris (pASP) and replacing QuilA by Al(OH)3. Immunization of cattle with the protective nASP+QuilA vaccine was associated with antigen-induced proliferation of natural killer (NK) cells combined with IFN-γ secretion and the induction of a mixed IgG1/IgG2 antibody response. ASP-specific activation and proliferation of NK cells was also observed in mice following the same vaccination regime. Replacing QuilA by Al(OH)3 or nASP by pASP significantly decreased the capacity of the vaccines to trigger both NK cell activation and antibody responses and failed to induce protection against a challenge infection. Reduction of the structurally anchoring disulphide bonds of the nASP completely abolished its ability to induce NK cell activation and antibody responses, highlighting the importance of protein conformation for the immunostimulatory activity. PMID:27403891

  18. Host protective ASP-based vaccine against the parasitic nematode Ostertagia ostertagi triggers NK cell activation and mixed IgG1-IgG2 response

    PubMed Central

    González-Hernández, Ana; Van Coppernolle, Stefanie; Borloo, Jimmy; Van Meulder, Frederik; Paerewijck, Oonagh; Peelaers, Iris; Leclercq, Georges; Claerebout, Edwin; Geldhof, Peter

    2016-01-01

    The mucus-dwelling parasite Ostertagia ostertagi is one of the most important gastrointestinal nematodes in cattle. Our group has previously demonstrated the protective capacity of a vaccine against this parasite based on a native activation-associated secreted protein ASP1 (nASP) in combination with the saponin adjuvant QuilA. The aim of the current study was to analyse the effect of both antigen and adjuvant on the cellular and humoral vaccine-induced immune responses by comparing the native ASP to a recombinant version expressed in Pichia pastoris (pASP) and replacing QuilA by Al(OH)3. Immunization of cattle with the protective nASP+QuilA vaccine was associated with antigen-induced proliferation of natural killer (NK) cells combined with IFN-γ secretion and the induction of a mixed IgG1/IgG2 antibody response. ASP-specific activation and proliferation of NK cells was also observed in mice following the same vaccination regime. Replacing QuilA by Al(OH)3 or nASP by pASP significantly decreased the capacity of the vaccines to trigger both NK cell activation and antibody responses and failed to induce protection against a challenge infection. Reduction of the structurally anchoring disulphide bonds of the nASP completely abolished its ability to induce NK cell activation and antibody responses, highlighting the importance of protein conformation for the immunostimulatory activity. PMID:27403891

  19. SPARC (secreted protein acidic and rich in cysteine) of the intestinal nematode Strongyloides ratti is involved in mucosa-associated parasite-host interaction.

    PubMed

    Anandarajah, Emmanuela M; Ditgen, Dana; Hansmann, Jan; Erttmann, Klaus D; Liebau, Eva; Brattig, Norbert W

    2016-06-01

    The secreted protein acidic and rich in cysteine (SPARC), found in the excretory/secretory products of Strongyloides ratti, is most strongly expressed in parasitic females. Since SPARC proteins are involved in the modulation of cell-matrix interactions, a role of the secreted S. ratti SPARC (Sr-SPARC) in the manifestation of the parasite in the host's intestine is postulated. The full-length cDNA of Sr-SPARC was identified and the protein was recombinantly expressed. The purified protein was biologically active, able to bind calcium, and to attach to mucosa-associated human cells. Addition of Sr-SPARC to an in vitro mucosal three-dimensional-cell culture model led to a time-dependent release of the cytokines TNF-α, IL-22, IL-10 and TSLP. Of importance, exposure with Sr-SPARC fostered wound closure in an intestinal epithelial cell model. Here, we demonstrate for the first time that SPARC released from the nematode is a multifunctional protein affecting the mucosal immune system. PMID:27268729

  20. The potential of nematophagous fungi to control the free-living stages of nematode parasites of sheep: towards the development of a fungal controlled release device.

    PubMed

    Waller, P J; Faedo, M; Ellis, K

    2001-12-28

    Studies showed that chlamydospores of the nematophagous fungus, Duddingtonia flagrans, are capable of surviving pressures of several tonnes when incorporated into matrices and pressed into tablets for the manufacture of prototype intraruminal controlled release devices (CRDs). They remain viable in this tabletted form for at least 9 months when stored at 4 degrees C. In vitro studies demonstrated that there was no effect on spore viability of prolonged exposure to either room or elevated temperature (40 degrees C) in air, or under an atmosphere of either of the major ruminal gases, carbon dioxide and methane. In vivo, studies showed that viable chlamydospores could be detected at the erosion surface of prototype CRDs recovered from the rumen and also in faeces of fistulated sheep, for up to 3 weeks after administration. Further studies have shown that chlamydospores released from such devices can substantially reduce the number of infective larvae that develop in cultures of faeces collected from sheep infected with the nematode parasite, Haemonchus contortus. This work demonstrates, in principle, that the deployment of chlamydospores of D. flagrans in intraruminal CRDs, is another possibility in the development of a range of methods for the biological control of parasites in livestock. PMID:11731073

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

    PubMed

    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.

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

    PubMed

    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. PMID:26100235

  3. Identifying Virulence-Associated Genes Using Transcriptomic and Proteomic Association Analyses of the Plant Parasitic Nematode Bursaphelenchus mucronatus

    PubMed Central

    Zhou, Lifeng; Chen, Fengmao; Pan, Hongyang; Ye, Jianren; Dong, Xuejiao; Li, Chunyan; Lin, Fengling

    2016-01-01

    Bursaphelenchus mucronatus (B. mucronatus) isolates that originate from different regions may vary in their virulence, but their virulence-associated genes and proteins are poorly understood. Thus, we conducted an integrated study coupling RNA-Seq and isobaric tags for relative and absolute quantitation (iTRAQ) to analyse transcriptomic and proteomic data of highly and weakly virulent B. mucronatus isolates during the pathogenic processes. Approximately 40,000 annotated unigenes and 5000 proteins were gained from the isolates. When we matched all of the proteins with their detected transcripts, a low correlation coefficient of r = 0.138 was found, indicating probable post-transcriptional gene regulation involved in the pathogenic processes. A functional analysis showed that five differentially expressed proteins which were all highly expressed in the highly virulent isolate were involved in the pathogenic processes of nematodes. Peroxiredoxin, fatty acid- and retinol-binding protein, and glutathione peroxidase relate to resistance against plant defence responses, while β-1,4-endoglucanase and expansin are associated with the breakdown of plant cell walls. Thus, the pathogenesis of B. mucronatus depends on its successful survival in host plants. Our work adds to the understanding of B. mucronatus’ pathogenesis, and will aid in controlling B. mucronatus and other pinewood nematode species complexes in the future. PMID:27618012

  4. Identifying Virulence-Associated Genes Using Transcriptomic and Proteomic Association Analyses of the Plant Parasitic Nematode Bursaphelenchus mucronatus.

    PubMed

    Zhou, Lifeng; Chen, Fengmao; Pan, Hongyang; Ye, Jianren; Dong, Xuejiao; Li, Chunyan; Lin, Fengling

    2016-01-01

    Bursaphelenchus mucronatus (B. mucronatus) isolates that originate from different regions may vary in their virulence, but their virulence-associated genes and proteins are poorly understood. Thus, we conducted an integrated study coupling RNA-Seq and isobaric tags for relative and absolute quantitation (iTRAQ) to analyse transcriptomic and proteomic data of highly and weakly virulent B. mucronatus isolates during the pathogenic processes. Approximately 40,000 annotated unigenes and 5000 proteins were gained from the isolates. When we matched all of the proteins with their detected transcripts, a low correlation coefficient of r = 0.138 was found, indicating probable post-transcriptional gene regulation involved in the pathogenic processes. A functional analysis showed that five differentially expressed proteins which were all highly expressed in the highly virulent isolate were involved in the pathogenic processes of nematodes. Peroxiredoxin, fatty acid- and retinol-binding protein, and glutathione peroxidase relate to resistance against plant defence responses, while β-1,4-endoglucanase and expansin are associated with the breakdown of plant cell walls. Thus, the pathogenesis of B. mucronatus depends on its successful survival in host plants. Our work adds to the understanding of B. mucronatus' pathogenesis, and will aid in controlling B. mucronatus and other pinewood nematode species complexes in the future. PMID:27618012

  5. The Heme Biosynthetic Pathway of the Obligate Wolbachia Endosymbiont of Brugia malayi as a Potential Anti-filarial Drug Target

    PubMed Central

    Wu, Bo; Novelli, Jacopo; Foster, Jeremy; Vaisvila, Romualdas; Conway, Leslie; Ingram, Jessica; Ganatra, Mehul; Rao, Anita U.; Hamza, Iqbal; Slatko, Barton

    2009-01-01

    Background Filarial parasites (e.g., Brugia malayi, Onchocerca volvulus, and Wuchereria bancrofti) are causative agents of lymphatic filariasis and onchocerciasis, which are among the most disabling of neglected tropical diseases. There is an urgent need to develop macro-filaricidal drugs, as current anti-filarial chemotherapy (e.g., diethylcarbamazine [DEC], ivermectin and albendazole) can interrupt transmission predominantly by killing microfilariae (mf) larvae, but is less effective on adult worms, which can live for decades in the human host. All medically relevant human filarial parasites appear to contain an obligate endosymbiotic bacterium, Wolbachia. This alpha-proteobacterial mutualist has been recognized as a potential target for filarial nematode life cycle intervention, as antibiotic treatments of filarial worms harboring Wolbachia result in the loss of worm fertility and viability upon antibiotic treatments both in vitro and in vivo. Human trials have confirmed this approach, although the length of treatments, high doses required and medical counter-indications for young children and pregnant women warrant the identification of additional anti-Wolbachia drugs. Methods and Findings Genome sequence analysis indicated that enzymes involved in heme biosynthesis might constitute a potential anti-Wolbachia target set. We tested different heme biosynthetic pathway inhibitors in ex vivo B. malayi viability assays and report a specific effect of N-methyl mesoporphyrin (NMMP), which targets ferrochelatase (FC, the last step). Our phylogenetic analysis indicates evolutionarily significant divergence between Wolbachia heme genes and their human homologues. We therefore undertook the cloning, overexpression and analysis of several enzymes of this pathway alongside their human homologues, and prepared proteins for drug targeting. In vitro enzyme assays revealed a ∼600-fold difference in drug sensitivities to succinyl acetone (SA) between Wolbachia and human 5

  6. Phylum-Level Conservation of Regulatory Information in Nematodes despite Extensive Non-coding Sequence Divergence

    PubMed Central

    Gordon, Kacy L.; Arthur, Robert K.; Ruvinsky, Ilya

    2015-01-01

    Gene regulatory information guides development and shapes the course of evolution. To test conservation of gene regulation within the phylum Nematoda, we compared the functions of putative cis-regulatory sequences of four sets of orthologs (unc-47, unc-25, mec-3 and elt-2) from distantly-related nematode species. These species, Caenorhabditis elegans, its congeneric C. briggsae, and three parasitic species Meloidogyne hapla, Brugia malayi, and Trichinella spiralis, represent four of the five major clades in the phylum Nematoda. Despite the great phylogenetic distances sampled and the extensive sequence divergence of nematode genomes, all but one of the regulatory elements we tested are able to drive at least a subset of the expected gene expression patterns. We show that functionally conserved cis-regulatory elements have no more extended sequence similarity to their C. elegans orthologs than would be expected by chance, but they do harbor motifs that are important for proper expression of the C. elegans genes. These motifs are too short to be distinguished from the background level of sequence similarity, and while identical in sequence they are not conserved in orientation or position. Functional tests reveal that some of these motifs contribute to proper expression. Our results suggest that conserved regulatory circuitry can persist despite considerable turnover within cis elements. PMID:26020930

  7. Phylum-Level Conservation of Regulatory Information in Nematodes despite Extensive Non-coding Sequence Divergence.

    PubMed

    Gordon, Kacy L; Arthur, Robert K; Ruvinsky, Ilya

    2015-05-01

    Gene regulatory information guides development and shapes the course of evolution. To test conservation of gene regulation within the phylum Nematoda, we compared the functions of putative cis-regulatory sequences of four sets of orthologs (unc-47, unc-25, mec-3 and elt-2) from distantly-related nematode species. These species, Caenorhabditis elegans, its congeneric C. briggsae, and three parasitic species Meloidogyne hapla, Brugia malayi, and Trichinella spiralis, represent four of the five major clades in the phylum Nematoda. Despite the great phylogenetic distances sampled and the extensive sequence divergence of nematode genomes, all but one of the regulatory elements we tested are able to drive at least a subset of the expected gene expression patterns. We show that functionally conserved cis-regulatory elements have no more extended sequence similarity to their C. elegans orthologs than would be expected by chance, but they do harbor motifs that are important for proper expression of the C. elegans genes. These motifs are too short to be distinguished from the background level of sequence similarity, and while identical in sequence they are not conserved in orientation or position. Functional tests reveal that some of these motifs contribute to proper expression. Our results suggest that conserved regulatory circuitry can persist despite considerable turnover within cis elements.

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

    PubMed Central

    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

  9. Life Cycle, Ultrastructure, and Host Specificity of the North American Isolate of Pasteuria that Parasitizes the Soybean Cyst Nematode, Heterodera glycines

    PubMed Central

    Atibalentja, N.; Jakstys, B. P.; Noel, G. R.

    2004-01-01

    Light and transmission electron microscopy were used to investigate the life cycle and ultrastructure of an undescribed isolate of Pasteuria that parasitizes the soybean cyst nematode, Heterodera glycines. Studies also were conducted to determine the host specificity of Pasteuria. The endospores that attached to the cuticle of second-stage juveniles (J2) of H. glycines in soil did not germinate until the encumbered nematodes invaded soybean roots. Thereafter, the bacterium developed and completed its life cycle only in females. The stages of endosporogenesis were typical of Pasteuria spp. The mature endospore, like that of P. nishizawae, the only other Pasteuria known to infect H. glycines, produces an epicortical layer that completely surrounds the cortex, an outer spore coat that tapers progressively from the top to the base of the central body, and a double basal adhesion layer. However, subtle differences exist between the Pasteuria from North America and P. nishizawae with regard to size of the central body, nature and function of the mesosomes observed in the earlier stages of endosporogenesis, and appearance of the fibers lining the basal adhesion layer and the exosporium of the mature endospore. Endospores of the North American Pasteuria attached to J2 of H. schachtii, H. trifolii, and H. lespedezae but not to Meloidogyne arenaria race 1, Tylenchorhynchus nudus, and Labronema sp. Results from this study indicate that the North American Pasteuria is more similar to P. nishizawae than to any other known member of the genus. Additional evidence from comparative analysis of 16S rDNA sequences is needed to clarify whether these two Pasteuria belong to the same species. PMID:19262804

  10. Galactosylated fucose epitopes in nematodes: increased expression in a Caenorhabditis mutant associated with altered lectin sensitivity and occurrence in parasitic species.

    PubMed

    Yan, Shi; Bleuler-Martinez, Silvia; Plaza, David Fernando; Künzler, Markus; Aebi, Markus; Joachim, Anja; Razzazi-Fazeli, Ebrahim; Jantsch, Verena; Geyer, Rudolf; Wilson, Iain B H; Paschinger, Katharina

    2012-08-17

    The modification of α1,6-linked fucose residues attached to the proximal (reducing-terminal) core N-acetylglucosamine residue of N-glycans by β1,4-linked galactose ("GalFuc" epitope) is a feature of a number of invertebrate species including the model nematode Caenorhabditis elegans. A pre-requisite for both core α1,6-fucosylation and β1,4-galactosylation is the presence of a nonreducing terminal N-acetylglucosamine; however, this residue is normally absent from the final glycan structure in invertebrates due to the action of specific hexosaminidases. Previously, we have identified two hexosaminidases (HEX-2 and HEX-3) in C. elegans, which process N-glycans. In the present study, we have prepared a hex-2;hex-3 double mutant, which possesses a radically altered N-glycomic profile. Whereas in the double mutant core α1,3-fucosylation of the proximal N-acetylglucosamine was abolished, the degree of galactosylation of core α1,6-fucose increased, and a novel Galα1,2Fucα1,3 moiety attached to the distal core N-acetylglucosamine residue was detected. Both galactosylated fucose moieties were also found in two parasitic nematodes, Ascaris suum and Oesophagostomum dentatum. As core modifications of N-glycans are known targets for fungal nematotoxic lectins, the sensitivity of the C. elegans double hexosaminidase mutant was assessed. Although this mutant displayed hypersensitivity to the GalFuc-binding lectin CGL2 and the N-acetylglucosamine-binding lectin XCL, the mutant was resistant to CCL2, which binds core α1,3-fucose. Thus, the use of C. elegans mutants aids the identification of novel N-glycan modifications and the definition of in vivo specificities of nematotoxic lectins with potential as anthelmintic agents.

  11. Effects of Temperature on Rate of Feeding of the Plant Parasitic Nematodes Rotylenchus robustus, Xiphinema diversicaudatum, and Hemicycliophora conida.

    PubMed

    Boag, B

    1980-07-01

    Rotylenchus robustus, Xiphinema diversicaudatum, and Hemicycgiophora conida were observed feeding over a range of temperatures on perennial rye-grass (Lolium perenne) seedlings grown on agar plates. R. robustus fed between 0.5 and 42.5 C, X. diversicaudatum between 5.0 and 37.0 C and H. conida between 5.0 and 34.0 C. Between 10 and 25 C there was a direct relationship between temperature and rate of esophageal bulb contractions. Above 25 C the number of esophageal contractions/min did not increase at the same rate and eventually decreased. At the extremes of temperature range, abnormal feeding behaviour was observed. Rates of esophageal bulb contraction did not differ in the different nematode life stages and sexes, or at different feeding sites on the roots.

  12. Use of two in vitro methods for the detection of anthelmintic resistant nematode parasites on Slovak sheep farms.

    PubMed

    Várady, Marián; Cernanská, Dana; Corba, Július

    2006-02-18

    A survey of the prevalence of anthelmintic resistant nematode populations was conducted on 32 sheep farms in the Slovak Republic. In vitro egg hatch test and larval development tests were used for the detection of resistance to benzimidazole anthelmintics and they were compared with in vivo faecal egg count reduction tests. There was agreement in the declaration of resistance between the faecal egg count reduction test and both in vitro tests. The presence of resistant populations was determined on two farms using egg hatch test. In both farms, the LD(50) values were higher than 0.1 microg TBZ/ml, indicating resistance. By using LD(99) values it might be possible to reveal relatively small proportion of resistant larvae in the population. The prevalence of benzimidazole resistance has not change on Slovak sheep farms during last decade.

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

    PubMed

    Vieira, Fabiano M; Pereira, Felipe B; Pantoja, Camila; Soares, Iris A; Pereira, Aldenice N; Timi, Juan T; Scholz, Tomáš; Luque, José L

    2015-11-05

    A taxonomic survey of six nematode species (including three new taxa) from the genus Cucullanus Müller, 1777, parasites of marine fishes off the Brazilian coast, is provided. Nematodes were studied using light and scanning electron microscopy (SEM). Cucullanus gastrophysi n. sp. parasitic in Lophius gastrophysus Miranda Ribeiro differs from its congeners by the combination of the following features: shape and number of sclerotized structures in the oesophastome (a pair of lateral elongate structures and a single small reniform one), position of deirids and excretory pore (both anterior to oesophagus base), spicule length and spicule/body length ratio (0.97-1.29 mm and 6.5-10.5%, respectively), morphology and length of gubernaculum (V-shaped, 107-135 µm long). Cucullanus protrudens n. sp. from Pagrus pagrus (Linnaeus) has the cloacal lips broadly protruded, which differentiates it from several species of Cucullanus; other features, e.g., the length of spicules and gubernaculum (400-415 µm and 91-103 µm, respectively), arrangement of caudal papillae and position of excretory pore (slightly posterior to oesophagus-intestine junction) also characterize this species. Cucullanus pseudopercis n. sp. from Pseudopercis semifasciata (Cuvier) has deirids and excretory pore posterior to the oesophagus-intestine junction, which distinguishes the species from most of the congeners; furthermore, the arrangement of caudal papillae in combination with the length of spicules and gubernaculum (1.0-1.5 mm and 178-196 µm, respectively) separate this species from other taxa. Newly collected specimens of C. cirratus Müller, 1777 (type species of the genus) from Urophycis brasiliensis (Kaup), C. pedroi from Conger orbignianus Valenciennes (type host of the species) and C. genypteri Sardella, Navone & Timi, 1997 from Genypterus brasiliensis Regan, were studied as well. Comparisons between newly collected samples and the taxonomic data available for each respective species revealed

  14. The expression of a naturally occurring, truncated allele of an α-SNAP gene suppresses plant parasitic nematode infection.

    PubMed

    Matsye, Prachi D; Lawrence, Gary W; Youssef, Reham M; Kim, Kyung-Hwan; Lawrence, Katheryn S; Matthews, Benjamin F; Klink, Vincent P

    2012-09-01

    Transcriptional mapping experiments of the major soybean cyst nematode resistance locus, rhg1, identified expression of the vesicular transport machinery component, α soluble NSF attachment protein (α-SNAP), occurring during defense. Sequencing the α-SNAP coding regions from the resistant genotypes G. max ([Peking/PI 548402]) and G. max ([PI 437654]) revealed they are identical, but differ from the susceptible G. max ([Williams 82/PI 518671]) by the presence of several single nucleotide polymorphisms. Using G. max ([Williams 82/PI 518671]) as a reference, a G → T(2,822) transversion in the genomic DNA sequence at a functional splice site of the α-SNAP([Peking/PI 548402]) allele produced an additional 17 nucleotides of mRNA sequence that contains an in-frame stop codon caused by a downstream G → A(2,832) transition. The G. max ([Peking/PI 548402]) genotype has cell wall appositions (CWAs), structures identified as forming as part of a defense response by the activity of the vesicular transport machinery. In contrast, the 17 nt α-SNAP([Peking/PI 548402]) mRNA motif is not found in G. max ([PI 88788]) that exhibits defense to H. glycines, but lack CWAs. The α-SNAP([PI 88788]) promoter contains sequence elements that are nearly identical to the α-SNAP([Peking/PI 548402]) allele, but differs from the G. max ([Williams 82/PI 518671]) ortholog. Overexpressing the α-SNAP([Peking/PI 548402]) allele in the susceptible G. max ([Williams 82/PI 518671]) genotype suppressed H. glycines infection. The experiments indicate a role for the vesicular transport machinery during infection of soybean by the soybean cyst nematode. However, increased GmEREBP1, PR1, PR2, PR5 gene activity but suppressed PR3 expression accompanied the overexpression of the α-SNAP([Peking/PI 548402]) allele prior to infection.

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

    PubMed

    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.

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

    PubMed Central

    2013-01-01

    Background 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. Methods 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. Results 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. Conclusions 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

  17. Morphological and Molecular Characterization of Longidorus americanum n. sp. (Nematoda: Longidoridae), a Needle Nematode Parasitizing Pine in Georgia.

    PubMed

    Handoo, Z A; Carta, L K; Skantar, A M; Ye, W; Robbins, R T; Subbotin, S A; Fraedrich, S W; Cram, M M

    2005-03-01

    We describe and illustrate a new needle nematode, Longidorus americanum n. sp., associated with patches of severely stunted and chlorotic loblolly pine, (Pinus taeda L.) seedlings in seedbeds at the Flint River Nursery (Byromville, GA). It is characterized by having females with a body length of 5.4-9.0 mm; lip region slightly swollen, anteriorly flattened, giving the anterior end a truncate appearance; long odontostyle (124-165 microm); vulva at 44%-52% of body length; and tail conoid, bluntly rounded to almost hemispherical. Males are rare but present, and in general shorter than females. The new species is morphologically similar to L. biformis, L. paravineacola, L. saginus, and L. tarjani but differs from these species either by the body, odontostyle and total stylet length, or by head and tail shape. Sequence data from the D2-D3 region of the 28S rDNA distinguishes this new species from other Longidorus species. Phylogenetic relationships of Longidorus americanum n. sp. with other longidorids based on analysis of this DNA fragment are presented. Additional information regarding the distribution of this species within the region is required.

  18. A novel cyclophilin from parasitic and free-living nematodes with a unique substrate- and drug-binding domain.

    PubMed

    Ma, Dong; Nelson, Laura S; LeCoz, Krystel; Poole, Catherine; Carlow, Clotilde K S

    2002-04-26

    A highly diversified member of the cyclophilin family of peptidyl-prolyl cis-trans isomerases has been isolated from the human parasite Onchocerca volvulus (OvCYP-16). This 25-kDa cyclophilin shares 43-46% similarity to other filarial cyclophilins but does not belong to any of the groups previously defined in invertebrates or vertebrates. A homolog was also isolated from Caenorhabditis elegans (CeCYP-16). Both recombinant O. volvulus and C. elegans cyclophilins were found to possess an enzyme activity with similar substrate preference and insensitivity to cyclosporin A. They represent novel cyclophilins with important differences in the composition of the drug-binding site in particular, namely, a Glu(124) (C. elegans) or Asp(123) (O. volvulus) residue present in a critical position. Site-directed mutagenesis studies and kinetic characterization demonstrated that the single residue dictates the degree of binding to substrate and cyclosporin A. CeCYP-16::GFP-expressing lines were generated with expression in the anterior and posterior distal portions of the intestine, in all larval stages and adults. An exception was found in the dauer stage, where fluorescence was observed in both the cell bodies and processes of the ventral chord motor neurons but was absent from the intestine. These studies highlight the extensive diversification of cyclophilins in an important human parasite and a closely related model organism.

  19. Detection of circulating parasite-derived microRNAs in filarial infections.

    PubMed

    Tritten, Lucienne; Burkman, Erica; Moorhead, Andrew; Satti, Mohammed; Geary, James; Mackenzie, Charles; Geary, Timothy

    2014-07-01

    Filarial nematodes cause chronic and profoundly debilitating diseases in both humans and animals. Applications of novel technology are providing unprecedented opportunities to improve diagnosis and our understanding of the molecular basis for host-parasite interactions. As a first step, we investigated the presence of circulating miRNAs released by filarial nematodes into the host bloodstream. miRNA deep-sequencing combined with bioinformatics revealed over 200 mature miRNA sequences of potential nematode origin in Dirofilaria immitis-infected dog plasma in two independent analyses, and 21 in Onchocerca volvulus-infected human serum. Total RNA obtained from D. immitis-infected dog plasma was subjected to stem-loop RT-qPCR assays targeting two detected miRNA candidates, miR-71 and miR-34. Additionally, Brugia pahangi-infected dog samples were included in the analysis, as these miRNAs were previously detected in extracts prepared from this species. The presence of miR-71 and miR-34 discriminated infected samples (both species) from uninfected samples, in which no specific miRNA amplification occurred. However, absolute miRNA copy numbers were not significantly correlated with microfilaraemia for either parasite. This may be due to the imprecision of mf counts to estimate infection intensity or to miRNA contributions from the unknown number of adult worms present. Nonetheless, parasite-derived circulating miRNAs are found in plasma or serum even for those species that do not live in the bloodstream. PMID:25033073

  20. Detection of circulating parasite-derived microRNAs in filarial infections.

    PubMed

    Tritten, Lucienne; Burkman, Erica; Moorhead, Andrew; Satti, Mohammed; Geary, James; Mackenzie, Charles; Geary, Timothy

    2014-07-01

    Filarial nematodes cause chronic and profoundly debilitating diseases in both humans and animals. Applications of novel technology are providing unprecedented opportunities to improve diagnosis and our understanding of the molecular basis for host-parasite interactions. As a first step, we investigated the presence of circulating miRNAs released by filarial nematodes into the host bloodstream. miRNA deep-sequencing combined with bioinformatics revealed over 200 mature miRNA sequences of potential nematode origin in Dirofilaria immitis-infected dog plasma in two independent analyses, and 21 in Onchocerca volvulus-infected human serum. Total RNA obtained from D. immitis-infected dog plasma was subjected to stem-loop RT-qPCR assays targeting two detected miRNA candidates, miR-71 and miR-34. Additionally, Brugia pahangi-infected dog samples were included in the analysis, as these miRNAs were previously detected in extracts prepared from this species. The presence of miR-71 and miR-34 discriminated infected samples (both species) from uninfected samples, in which no specific miRNA amplification occurred. However, absolute miRNA copy numbers were not significantly correlated with microfilaraemia for either parasite. This may be due to the imprecision of mf counts to estimate infection intensity or to miRNA contributions from the unknown number of adult worms present. Nonetheless, parasite-derived circulating miRNAs are found in plasma or serum even for those species that do not live in the bloodstream.

  1. In Planta Processing and Glycosylation of a Nematode CLAVATA3/ENDOSPERM SURROUNDING REGION-Like Effector and Its Interaction with a Host CLAVATA2-Like Receptor to Promote Parasitism1[OPEN

    PubMed Central

    Chen, Shiyan; Lang, Ping; Chronis, Demosthenis; Zhang, Sheng; De Jong, Walter S.; Mitchum, Melissa G.

    2015-01-01

    Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ENDOSPERM SURROUNDING REGION-related (CLE) proteins have been identified in several cyst nematodes, including the potato cyst nematode (PCN); however, the mechanistic details of this cross-kingdom mimicry are poorly understood. Plant CLEs are posttranslationally modified and proteolytically processed to function as bioactive ligands critical to various aspects of plant development. Using ectopic expression coupled with nanoliquid chromatography-tandem mass spectrometry analysis, we show that the in planta mature form of proGrCLE1, a multidomain CLE effector secreted by PCN during infection, is a 12-amino acid arabinosylated glycopeptide (named GrCLE1-1Hyp4,7g) with striking structural similarity to mature plant CLE peptides. This glycopeptide is more resistant to hydrolytic degradation and binds with higher affinity to a CLAVATA2-like receptor (StCLV2) from potato (Solanum tuberosum) than its nonglycosylated forms. We further show that StCLV2 is highly up-regulated at nematode infection sites and that transgenic potatoes with reduced StCLV2 expression are less susceptible to PCN infection, indicating that interference of the CLV2-mediated signaling pathway confers nematode resistance in crop plants. These results strongly suggest that phytonematodes have evolved to utilize host cellular posttranslational modification and processing machinery for the activation of CLE effectors following secretion into plant cells and highlight the significance of arabinosylation in regulating nematode CLE effector activity. Our finding also provides evidence that multidomain CLEs are modified and processed similarly to single-domain CLEs, adding new insight into CLE maturation in plants. PMID:25416475

  2. In planta processing and glycosylation of a nematode CLAVATA3/ENDOSPERM SURROUNDING REGION-like effector and its interaction with a host CLAVATA2-like receptor to promote parasitism.

    PubMed

    Chen, Shiyan; Lang, Ping; Chronis, Demosthenis; Zhang, Sheng; De Jong, Walter S; Mitchum, Melissa G; Wang, Xiaohong

    2015-01-01

    Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ENDOSPERM SURROUNDING REGION-related (CLE) proteins have been identified in several cyst nematodes, including the potato cyst nematode (PCN); however, the mechanistic details of this cross-kingdom mimicry are poorly understood. Plant CLEs are posttranslationally modified and proteolytically processed to function as bioactive ligands critical to various aspects of plant development. Using ectopic expression coupled with nanoliquid chromatography-tandem mass spectrometry analysis, we show that the in planta mature form of proGrCLE1, a multidomain CLE effector secreted by PCN during infection, is a 12-amino acid arabinosylated glycopeptide (named GrCLE1-1Hyp4,7g) with striking structural similarity to mature plant CLE peptides. This glycopeptide is more resistant to hydrolytic degradation and binds with higher affinity to a CLAVATA2-like receptor (StCLV2) from potato (Solanum tuberosum) than its nonglycosylated forms. We further show that StCLV2 is highly up-regulated at nematode infection sites and that transgenic potatoes with reduced StCLV2 expression are less susceptible to PCN infection, indicating that interference of the CLV2-mediated signaling pathway confers nematode resistance in crop plants. These results strongly suggest that phytonematodes have evolved to utilize host cellular posttranslational modification and processing machinery for the activation of CLE effectors following secretion into plant cells and highlight the significance of arabinosylation in regulating nematode CLE effector activity. Our finding also provides evidence that multidomain CLEs are modified and processed similarly to single-domain CLEs, adding new insight into CLE maturation in plants. PMID:25416475

  3. Expression, purification and enzymatic characterization of Brugia malayi dihydrofolate reductase.

    PubMed

    Perez-Abraham, Romy; Sanchez, Karla Garabiles; Alfonso, Melany; Gubler, Ueli; Siekierka, John J; Goodey, Nina M

    2016-12-01

    Brugia malayi (B. malayi) is one of the three causative agents of lymphatic filariasis, a neglected parasitic disease. Current literature suggests that dihydrofolate reductase is a potential drug target for the elimination of B. malayi. Here we report the recombinant expression and purification of a ∼20 kDa B. malayi dihydrofolate reductase (BmDHFR). A His6-tagged construct was expressed in E. coli and purified by affinity chromatography to yield active and homogeneous enzyme for steady-state kinetic characterization and inhibition studies. The catalytic activity kcat was found to be 1.4 ± 0.1 s(-1), the Michaelis Menten constant KM for dihydrofolate 14.7 ± 3.6 μM, and the equilibrium dissociation constant KD for NADPH 25 ± 24 nM. For BmDHFR, IC50 values for a six DHFR inhibitors were determined to be 3.1 ± 0.2 nM for methotrexate, 32 ± 22 μM for trimethoprim, 109 ± 34 μM for pyrimethamine, 154 ± 46 μM for 2,4-diaminoquinazoline, 771 ± 44 μM for cycloguanil, and >20,000 μM for 2,4-diaminopyrimidine. Our findings suggest that antifolate compounds can serve as inhibitors of BmDHFR. PMID:27544923

  4. First description of gastrointestinal nematodes of Barbary sheep (Ammotragus lervia): the case of Camelostrongylus mentulatus as a paradigm of phylogenic and specific relationship between the parasite and its ancient host.

    PubMed

    Mayo, E; Ortiz, J; Martínez-Carrasco, C; Garijo, M M; Espeso, G; Hervías, S; Ruiz de Ybáñez, M R

    2013-09-01

    The gastrointestinal helminth fauna of 24 Barbary sheep or Aoudad (Ammotragus lervia sahariensis) maintained in the Parque de Rescate de la Fauna Sahariana (PRFS, CSIC, Almeria, Spain) was analyzed. Most animals (87.5 %) were parasitized, and multiple infections were highly present. The following species were identified: Camelostrongylus mentulatus, Teladorsagia circumcincta, Marshallagia marshalli, Ostertagia ostertagi, O. leptospicularis, O. lyrata, Haemonchus contortus, Teladorsagia trifurcata, Trichostrongylus vitrinus, T. colubriformis, T. probolorus, T. capricola, Nematodirus spathiger, N. abnormalis, N. filicollis, N. helvetianus, Trichuris spp. and Skrjabinema ovis. Teladorsagia circumcincta was the most prevalent nematode in abomasum (52.6 %) followed by C. mentulatus (50 %). However, this latter nematode had the greater mean intensity and abundance. In the small intestine, T. colubriformis and T. vitrinus had the highest prevalence (36.4 %); the last one showed also the greater mean intensity and abundance. It should be emphasized the presence of Skrjabinema ovis (prevalence 39.1 %) in the large intestine, showing the greater mean abundance and intensity, although with a low values. Camelostrongylus mentulatus could be the most primitive nematode of the family trichostrongylidae recovered in this study; attending to its high prevalence, mean abundance and mean intensity, the possible specificity between this parasite and the Aoudad is discussed.

  5. [2 trichostrongyloid nematodes parasites of an African murid. II. Chronology of cycles and description of larval and immature stages].

    PubMed

    Durette-Desset, M C; Cassone, J

    1987-01-01

    Larval and immature forms in Neoheligmonella dossoi and N. tranieri (Nippostrongylinae) coparasites of Uranomys ruddi from Africa are described. The free larval stages of both species cannot be distinguished one from the other. L1, L2 and L3 are identified by their size and by shape and tail length. In the parasitic larval stages the males are distinguished from females as from the second day after infestation: the female genital primordium is displaced to the caudal extremity in a very significant way. The L4 can be separated from L3 by the presence of a cephalic vesicle and a synlophe; the immature specimens from L4 due to the presence of a new cephalic vesicle and the synlophe of adult. A specific name can be given to those larvae from day 3 after the infestation: plotting the length of the genital primordium in relation to total body length shows two distinct clouds representing a large and a small species. Similar clouds were obtained for day 4 to 7 post-infection. By day 6, the immature forms of the small species can be identified by the synlophe as dossoi and those of the large species as tranieri. The larval development of N. dossoi is slower than that of N. tranieri.

  6. [Evolution and systematics of nematodes based on molecular investigation].

    PubMed

    Okulewicz, Anna; Perec, Agnieszka

    2004-01-01

    Evolution and systematics of nematodes based on molecular investigation. The use of molecular phylogenetics to examine the interrelationships between animal parasites, free-living nematodes, and plant parasites versus traditional classification based on morphological-ecological characters was discussed and reviewed. Distinct differences were observed between parasitic nematodes and free-living ones. Within the former group, animal parasites turned out to be distinctly different from plant parasites. Using small subunit of ribosomal RNA gene sequence from a wide range of nematodes, there is a possibility to compare animal-parasitic, plant-parasitic and free-living taxa. Nowadays the parasitic nematodes expressed sequence tag (EST) project is currently generating sequence information to provide a new source of data to examine the evolutionary history of this taxonomic group. PMID:16859012

  7. Monoclonal antibody to a unique surface epitope of the human filaria Brugia malayi identifies infective larvae in mosquito vectors.

    PubMed Central

    Carlow, C K; Franke, E D; Lowrie, R C; Partono, F; Philipp, M

    1987-01-01

    We describe properties of an IgM monoclonal antibody (NEB-D1E5) raised against the human filarial parasite Brugia malayi. The antibody reacts with a stage- and species-specific determinant located on the surface of the infective-stage larva, as determined by indirect immunofluorescence. To use this reagent in epidemiological field studies, we developed an enzyme-linked immunoassay with which B. malayi larvae can be differentiated from other filarial parasites in mosquito vectors, including the morphologically indistinguishable parasite of animals Brugia pahangi. The immunoenzyme assay was 91-94% specific and 90-97% sensitive when performed on infected mosquitoes. In the absence of mosquito tissue, the levels of specificity and sensitivity increased to 100% and 97.5-100%, respectively. Binding of antibody to the surface of living larvae was abrogated by treatment of the worms with the enzymes pronase and proteinase K and with the detergents Triton X-100, octyl beta-D-glucopyranoside, and 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulphonate (CHAPS). In contrast, treatment with trypsin, endoglycosidase-F, O-Glycanase, N-Glycanase, lipase, various phospholipases, boiling, 2-mercaptoethanol at 37 degrees C, or periodate did not reduce the antigenicity of the larval surface to antibody NEB-D1E5. These results suggest that the species-specific epitope is a peptide domain attached to a hydrophobic anchoring residue. Images PMID:2443912

  8. In vitro biological evaluation of biguanides and dihydrotriazines against Brugia malayi and folate reversal studies.

    PubMed

    Bag, Seema; Tawari, Nilesh R; Sharma, Richa; Goswami, Kalyan; Reddy, M V R; Degani, Mariam S

    2010-01-01

    Dihydrofolate reductase (DHFR) is a well-known target for antibacterial and anticancer therapy. DHFR inhibitors are useful for protozoan parasites, but are yet to be explored against metazoan species; hence the present work was designed to evaluate the efficacy of DHFR inhibitors against filariasis, one of the major neglected tropical diseases. Molecules from our in-house library of synthetic antifolate agents (biguanide and dihydrotriazine derivatives) were evaluated along with the antimalarial drug pyrimethamine and the antibacterial drug trimethoprim in an in vitro model against Brugia malayi microfilariae (Mf). Three biguanides and two dihydrotriazines were more potent than trimethoprim and pyrimethamine against B. malayi Mf. Trimethoprim, pyrimethamine and four of the five compounds active against Mf were also active against adult worms. To probe the mechanism of action of the compounds, reversal of activity of active compounds by folic acid and folinic acid was studied. In conclusion, DHFR inhibitors could be used as leads for new antifilarial drugs.

  9. The Wolbachia endosymbiont of Brugia malayi has an active pyruvate phosphate dikinase.

    PubMed

    Raverdy, Sylvine; Foster, Jeremy M; Roopenian, Erica; Carlow, Clotilde K S

    2008-08-01

    Genome analysis of the glycolytic/gluconeogenic pathway in the Wolbachia endosymbiont from the filarial parasite Brugia malayi (wBm) has revealed that wBm lacks pyruvate kinase (PK) and may instead utilize the enzyme pyruvate phosphate dikinase (PPDK; ATP:pyruvate, orthophosphate phosphotransferase, EC 2.7.9.1). PPDK catalyses the reversible conversion of AMP, PPi and phosphoenolpyruvate (PEP) into ATP, Pi and pyruvate. The glycolytic pathway of most organisms, including mammals, contains exclusively PK for the production of pyruvate from PEP. Therefore, the absence of PPDK in mammals makes the enzyme an attractive Wolbachia drug target. In the present study, we have cloned and expressed an active wBm-PPDK, thereby providing insight into the energy metabolism of the endosymbiont. Our results support the development of wBm-PPDK as a promising new drug target in an anti-symbiotic approach to controlling filarial infection.

  10. In Vivo Production of Entomopathogenic Nematodes.

    PubMed

    Shapiro-Ilan, David I; Morales-Ramos, Juan A; Rojas, M Guadalupe

    2016-01-01

    In nature, entomopathogenic nematodes in the genera Heterorhabditis and Steinernema are obligate parasites of insects. The nematodes are used widely as biopesticides for suppression of insect pests. More than a dozen entomopathogenic nematode species have been commercialized for use in biological control. Most nematodes intended for commercial application are produced in artificial media via solid or liquid fermentation. However, for laboratory research and small greenhouse or field trials, in vivo production of entomopathogenic nematodes is the common method of propagation. Additionally, small companies continue to produce nematodes using in vivo methods for application in niche markets. Advances in mechanization and alternative production routes (e.g., production geared toward application of nematodes in infected host cadavers) can improve efficiency and economy of scale. The objective of this chapter is to describe basic and advanced procedures for in vivo production of entomopathogenic nematodes. PMID:27565497

  11. Comparative tissue pharmacokinetics and efficacy of moxidectin, abamectin and ivermectin in lambs infected with resistant nematodes: Impact of drug treatments on parasite P-glycoprotein expression☆

    PubMed Central

    Lloberas, Mercedes; Alvarez, Luis; Entrocasso, Carlos; Virkel, Guillermo; Ballent, Mariana; Mate, Laura; Lanusse, Carlos; Lifschitz, Adrian

    2012-01-01

    The high level of resistance to the macrocyclic lactones has encouraged the search for strategies to optimize their potential as antiparasitic agents. There is a need for pharmaco-parasitological studies addressing the kinetic-dynamic differences between various macrocyclic lactones under standardized in vivo conditions. The current work evaluated the relationship among systemic drug exposure, target tissue availabilities and the pattern of drug accumulation within resistant Haemonchus contortus for moxidectin, abamectin and ivermectin. Drug concentrations in plasma, target tissues and parasites were measured by high performance liquid chromatography. Additionally, the efficacy of the three molecules was evaluated in lambs infected with resistant nematodes by classical parasitological methods. Furthermore, the comparative determination of the level of expression of P-glycoprotein (P-gp2) in H. contortus recovered from lambs treated with each drug was performed by real time PCR. A longer persistence of moxidectin (P < 0.05) concentrations in plasma was observed. The concentrations of the three compounds in the mucosal tissue and digestive contents were significant higher than those measured in plasma. Drug concentrations were in a range between 452 ng/g (0.5 day post-treatment) and 32 ng/g (2 days post-treatment) in the gastrointestinal (GI) contents (abomasal and intestinal). Concentrations of the three compounds in H. contortus were in a similar range to those observed in the abomasal contents (positive correlation P = 0.0002). Lower moxidectin concentrations were recovered within adult H. contortus compared to abamectin and ivermectin at day 2 post-treatment. However, the efficacy against H. contortus was 20.1% (ivermectin), 39.7% (abamectin) and 89.6% (moxidectin). Only the ivermectin treatment induced an enhancement on the expression of P-gp2 in the recovered adult H. contortus, reaching higher values at 12 and 24 h post-administration compared to

  12. Nematode cholinergic pharmacology

    SciTech Connect

    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.

  13. Tidal-Flat Macrobenthos as Diets of the Japanese Eel Anguilla japonica in Western Japan, with a Note on the Occurrence of a Parasitic Nematode Heliconema anguillae in Eel Stomachs.

    PubMed

    Kan, Kotaro; Sato, Masanori; Nagasawa, Kazuya

    2016-02-01

    Dietary items of the Japanese eel Anguilla japonica inhabiting estuaries were examined by analyses of the gut (stomach and intestine) contents in two areas in Kyushu, western Japan. In a small estuary in Kagoshima Bay, where seven eel guts were examined, almost all of the dietary organisms consisted of Hemigrapsus crabs and Hediste polychaetes, both of which commonly occurred on tidal flats of this site during our survey on the macrobenthic fauna. In another large estuary in the innermost part of the Ariake Sea, where 14 eel guts were examined, 11 macrobenthic species (nine crustaceans, a polychaete, and a gastropod) were found in the gut contents, mostly consisting of mudflat-specific species. The dietary items are almost completely different not only between the two estuaries, but also among three neighboring sites within the large estuary in the Ariake Sea. These results show that Japanese eels feed on various macrobenthic invertebrates inhabiting estuarine tidal flats at each site. The variety of the prey species occupying different habitats indicates that their foraging areas extend to a wide range of estuarine tidal flats from the upper to lower littoral zones. The physalopterid nematode Heliconema anguillae was found parasitic in eel stomachs in both estuaries. The prevalence of the nematode was higher in the estuary in Kagoshima Bay (100%) than that in the Ariake Sea (43%), although the intensity in the former (4-94 nematodes per infected stomach) was comparable to that of the latter (2-96). The relationship between the nematode infection and the dietary items of Japanese eels is discussed.

  14. Tidal-Flat Macrobenthos as Diets of the Japanese Eel Anguilla japonica in Western Japan, with a Note on the Occurrence of a Parasitic Nematode Heliconema anguillae in Eel Stomachs.

    PubMed

    Kan, Kotaro; Sato, Masanori; Nagasawa, Kazuya

    2016-02-01

    Dietary items of the Japanese eel Anguilla japonica inhabiting estuaries were examined by analyses of the gut (stomach and intestine) contents in two areas in Kyushu, western Japan. In a small estuary in Kagoshima Bay, where seven eel guts were examined, almost all of the dietary organisms consisted of Hemigrapsus crabs and Hediste polychaetes, both of which commonly occurred on tidal flats of this site during our survey on the macrobenthic fauna. In another large estuary in the innermost part of the Ariake Sea, where 14 eel guts were examined, 11 macrobenthic species (nine crustaceans, a polychaete, and a gastropod) were found in the gut contents, mostly consisting of mudflat-specific species. The dietary items are almost completely different not only between the two estuaries, but also among three neighboring sites within the large estuary in the Ariake Sea. These results show that Japanese eels feed on various macrobenthic invertebrates inhabiting estuarine tidal flats at each site. The variety of the prey species occupying different habitats indicates that their foraging areas extend to a wide range of estuarine tidal flats from the upper to lower littoral zones. The physalopterid nematode Heliconema anguillae was found parasitic in eel stomachs in both estuaries. The prevalence of the nematode was higher in the estuary in Kagoshima Bay (100%) than that in the Ariake Sea (43%), although the intensity in the former (4-94 nematodes per infected stomach) was comparable to that of the latter (2-96). The relationship between the nematode infection and the dietary items of Japanese eels is discussed. PMID:26853869

  15. On a new nematode Leipernema leiperi n.g., n.sp. (Strongyloididae), parasitic in the pangolin Manis pentadactyla from Hyderabad, India.

    PubMed

    Singh, S N

    1976-12-01

    Leipernema leiperi n.g., n.sp. is described from the pangolin Manis pentadactyla in India. Both parasitic free-living generations have been examined. Features which differentiate the parasite from Strongyloides and Parastrongyloides are described.

  16. Brugia malayi Asparaginyl - tRNA Synthetase Stimulates Endothelial Cell Proliferation, Vasodilation and Angiogenesis

    PubMed Central

    D, Jeeva Jothi; Dhanraj, Muthu; Solaiappan, Shanmugam; Sivanesan, Sanjana; Kron, Michael; Dhanasekaran, Anuradha

    2016-01-01

    A hallmark of chronic infection with lymphatic filarial parasites is the development of lymphatic disease which often results in permanent vasodilation and lymphedema, but all of the mechanisms by which filarial parasites induce pathology are not known. Prior work showed that the asparaginyl-tRNA synthetase (BmAsnRS) of Brugia malayi, an etiological agent of lymphatic filariasis, acts as a physiocrine that binds specifically to interleukin-8 (IL-8) chemokine receptors. Endothelial cells are one of the many cell types that express IL-8 receptors. IL-8 also has been reported previously to induce angiogenesis and vasodilation, however, the effect of BmAsnRS on endothelial cells has not been reported. Therefore, we tested the hypothesis that BmAsnRS might produce physiological changes in endothelial by studying the in vitro effects of BmAsnRS using a human umbilical vein cell line EA.hy926 and six different endothelial cell assays. Our results demonstrated that BmAsnRS produces consistent and statistically significant effects on endothelial cells that are identical to the effects of VEGF, vascular endothelial growth factor. This study supports the idea that new drugs or immunotherapies that counteract the adverse effects of parasite-derived physiocrines may prevent or ameliorate the vascular pathology observed in patients with lymphatic filariasis. PMID:26751209

  17. The Wolbachia endosymbiont of Brugia malayi has an active phosphoglycerate mutase: a candidate target for anti-filarial therapies.

    PubMed

    Foster, Jeremy M; Raverdy, Sylvine; Ganatra, Mehul B; Colussi, Paul A; Taron, Christopher H; Carlow, Clotilde K S

    2009-04-01

    Phosphoglycerate mutases (PGM) interconvert 2- and 3-phosphoglycerate in the glycolytic and gluconeogenic pathways. A putative cofactor-independent phosphoglycerate mutase gene (iPGM) was identified in the genome sequence of the Wolbachia endosymbiont from the filarial nematode, Brugia malayi (wBm). Since iPGM has no sequence or structural similarity to the cofactor-dependent phosphoglycerate mutase (dPGM) found in mammals, it may represent an attractive Wolbachia drug target. In the present study, wBm-iPGM cloned and expressed in Escherichia coli was mostly insoluble and inactive. However, the protein was successfully produced in the yeast Kluyveromyces lactis and the purified recombinant wBm-iPGM showed typical PGM activity. Our results provide a foundation for further development of wBm-iPGM as a promising new drug target for novel anti-filarial therapies that selectively target the endosymbiont.

  18. DEAD/DExH-Box RNA Helicases in Selected Human Parasites.

    PubMed

    Marchat, Laurence A; Arzola-Rodríguez, Silvia I; Hernandez-de la Cruz, Olga; Lopez-Rosas, Itzel; Lopez-Camarillo, Cesar

    2015-10-01

    DEAD/DExH-box RNA helicases catalyze the folding and remodeling of RNA molecules in prokaryotic and eukaryotic cells, as well as in many viruses. They are characterized by the presence of the helicase domain with conserved motifs that are essential for ATP binding and hydrolysis, RNA interaction, and unwinding activities. Large families of DEAD/DExH-box proteins have been described in different organisms, and their role in all molecular processes involving RNA, from transcriptional regulation to mRNA decay, have been described. This review aims to summarize the current knowledge about DEAD/DExH-box proteins in selected protozoan and nematode parasites of medical importance worldwide, such as Plasmodium falciparum, Leishmania spp., Trypanosoma spp., Giardia lamblia, Entamoeba histolytica, and Brugia malayi. We discuss the functional characterization of several proteins in an attempt to understand better the molecular mechanisms involving RNA in these pathogens. The current data also highlight that DEAD/DExH-box RNA helicases might represent feasible drug targets due to their vital role in parasite growth and development.

  19. DEAD/DExH-Box RNA Helicases in Selected Human Parasites

    PubMed Central

    Marchat, Laurence A.; Arzola-Rodríguez, Silvia I.; Hernandez-de la Cruz, Olga; Lopez-Rosas, Itzel; Lopez-Camarillo, Cesar

    2015-01-01

    DEAD/DExH-box RNA helicases catalyze the folding and remodeling of RNA molecules in prokaryotic and eukaryotic cells, as well as in many viruses. They are characterized by the presence of the helicase domain with conserved motifs that are essential for ATP binding and hydrolysis, RNA interaction, and unwinding activities. Large families of DEAD/DExH-box proteins have been described in different organisms, and their role in all molecular processes involving RNA, from transcriptional regulation to mRNA decay, have been described. This review aims to summarize the current knowledge about DEAD/DExH-box proteins in selected protozoan and nematode parasites of medical importance worldwide, such as Plasmodium falciparum, Leishmania spp., Trypanosoma spp., Giardia lamblia, Entamoeba histolytica, and Brugia malayi. We discuss the functional characterization of several proteins in an attempt to understand better the molecular mechanisms involving RNA in these pathogens. The current data also highlight that DEAD/DExH-box RNA helicases might represent feasible drug targets due to their vital role in parasite growth and development. PMID:26537038

  20. Neuroparasitic Infections: Nematodes

    PubMed Central

    Walker, M.D.; Zunt, J.R.

    2009-01-01

    Globalization has produced an increase in the number of people at risk for contracting parasitic infection. Central nervous system infection by nematodal parasites can be devastating. Early recognition and treatment of infection can significantly decrease morbidity of the parasitic infection, as well as the risk of secondary superinfection. The clinical presentation, diagnosis, and treatment for five of the more common nematodal infections of the nervous system—Angiostrongylus spp., Baylisacaris procyonis, Gnathostoma spinigerum, Strongyloides stercoralis, and Toxocara spp.—is reviewed. Objectives On completion of this article, the reader should be able to summarize the clinical presentation, diagnosis, and treatment of the common nematodal infections of the nervous system. Accreditation The Indiana University School of Medicine is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. Credit The Indiana University School of Medicine designates this educational activity for a maximum of 1 Category 1 credit toward the AMA Physicians Recognition Award. Each physician should claim only those credits that he/she actually spent in the educational activity. Disclosure Statements of disclosure have been obtained regarding the authors’ relevant financial relationships. The authors have nothing to disclose. PMID:16170738

  1. Endemic Oscheius Nematodes of Hawai'i

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic nematodes (EPNs) parasitize insects utilizing mutualistic bacteria to kill the host, allowing the nematode to feed and reproduce within the insect cadaver. Consequently EPNs are highly sought after for their biological control potential. A survey for EPNs was conducted on O’ahu and...

  2. Interspecific nematode signals regulate dispersal behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2) of plant parasitic Meloidogyne spp. and infective ...

  3. Nematode CLE signaling in Arabidopsis requires CLAVATA2 and CORYNE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant-parasitic cyst nematodes secrete CLAVATA3 (CLV3)/ESR(CLE)-like effector proteins. These proteins have been shown to act as ligand mimics of plant CLE peptides and are required for successful nematode infection; however, the receptors for nematode CLE-like peptides have not been identified. Her...

  4. Distribution of Brugia malayi larvae and DNA in vector and non-vector mosquitoes: implications for molecular diagnostics

    PubMed Central

    2009-01-01

    Background The purpose of this study was to extend prior studies of molecular detection of Brugia malayi DNA in vector (Aedes aegypti- Liverpool) and non-vector (Culex pipiens) mosquitoes at different times after ingestion of infected blood. Results Parasite DNA was detected over a two week time course in 96% of pooled thoraces of vector mosquitoes. In contrast, parasite DNA was detected in only 24% of thorax pools from non-vectors; parasite DNA was detected in 56% of midgut pools and 47% of abdomen pools from non-vectors. Parasite DNA was detected in vectors in the head immediately after the blood meal and after 14 days. Parasite DNA was also detected in feces and excreta of the vector and non-vector mosquitoes which could potentially confound results obtained with field samples. However, co-housing experiments failed to demonstrate transfer of parasite DNA from infected to non-infected mosquitoes. Parasites were also visualized in mosquito tissues by immunohistololgy using an antibody to the recombinant filarial antigen Bm14. Parasite larvae were detected consistently after mf ingestion in Ae. aegypti- Liverpool. Infectious L3s were seen in the head, thorax and abdomen of vector mosquitoes 14 days after Mf ingestion. In contrast, parasites were only detected by histology shortly after the blood meal in Cx. pipiens, and these were not labeled by the antibody. Conclusion This study provides new information on the distribution of filarial parasites and parasite DNA in vector and non-vector mosquitoes. This information should be useful for those involved in designing and interpreting molecular xenomonitoring studies. PMID:19922607

  5. The complete mitochondrial genome sequence of the filarial nematode Wuchereria bancrofti from three geographic isolates provides evidence of complex demographic history.

    PubMed

    Ramesh, Akshaya; Small, Scott T; Kloos, Zachary A; Kazura, James W; Nutman, Thomas B; Serre, David; Zimmerman, Peter A

    2012-05-01

    Mitochondrial (mt) genome sequences have enabled comparison of population genetics and evolution for numerous free-living and parasitic nematodes. Here we define the complete mt genome of Wuchereria bancrofti through analysis of isolates from Papua New Guinea, India and West Africa. Sequences were assembled for each isolate and annotated with reference to the mt genome sequence for Brugia malayi. The length of the W. bancrofti mt genome is approximately 13,637 nucleotides, contains 2 ribosomal RNAs (rrns), 22 transfer RNAs (trns), 12 protein-coding genes, and is characterized by a 74.6% AT content. The W. bancrofti mt gene order is identical to that reported for Onchocerca volvulus, Dirofilaria immitis, Setaria digitata and B. malayi. In addition to using translational start codons identified previously in the mt protein-coding genes of other filarial nematodes, W. bancrofti appears to be unique in using TGT as a translational start codon. Similarly, use of incomplete stop codons in mt protein-coding genes appears to be more common in W. bancrofti than in other human filarial parasites. The complete mt genome sequence reported here provides new genetic markers for investigating phylogenetic and geographic relationships between isolates, and assessing population diversity within endemic regions. The sequence polymorphism enables new strategies to monitor the progress of public health interventions to control and eliminate this important human parasite. We illustrate the utility of this sequence and single nucleotide polymorphisms by inferring the divergence times between the three W. bancrofti isolates, suggesting predictions into their origin and migration. PMID:22326389

  6. Trichinella spiralis: the evolution of adaptation and parasitism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parasitism among nematodes has occurred in multiple, independent events. Deciphering processes that drive species diversity and adaptation are keys to understanding parasitism and advancing control strategies. Studies have been put forth on morphological and physiological aspects of parasitism and a...

  7. Occurrence and distribution of nematodes in Idaho crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surveys were conducted in Idaho during the 2000-2006 cropping seasons to study the occurrence, population density, host association and distribution of plant-parasitic nematodes associated with major crops, grasses and weeds. Eighty-four species and 43 genera of plant-parasitic nematodes were record...

  8. Regulatory interplay between soybean root and soybean cyst nematode during a resistant and susceptible reaction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Plant parasitic nematodes (PPNs) are obligate parasites that feed on the roots of living host plants. Often, these nematodes can lay hundreds of eggs, each capable of surviving in the soil for as long as 12 years. When it comes to wreaking havoc on agricultural yield, few nematodes can c...

  9. Molecular characterization of the reniform nematode C-type lectin gene family reveals a likely role in mitigating environmental stresses during plant parasitism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The reniform nematode, Rotylenchulus reniformis, is a damaging semi-endoparasitic pathogen of more than 300 plant species. As a sedentary obligate biotroph, R. reniformis must establish a complex feeding site within the root vasculature that functions as a continuous supply of nutrients. It was re...

  10. Nematode feeding sites: unique organs in plant roots.

    PubMed

    Kyndt, Tina; Vieira, Paulo; Gheysen, Godelieve; de Almeida-Engler, Janice

    2013-11-01

    Although generally unnoticed, nearly all crop plants have one or more species of nematodes that feed on their roots, frequently causing tremendous yield losses. The group of sedentary nematodes, which are among the most damaging plant-parasitic nematodes, cause the formation of special organs called nematode feeding sites (NFS) in the root tissue. In this review we discuss key metabolic and cellular changes correlated with NFS development, and similarities and discrepancies between different types of NFS are highlighted.

  11. Management of the Citrus Nematode, Tylenchulus semipenetrans

    PubMed Central

    Verdejo-Lucas, S.; McKenry, M. V.

    2004-01-01

    Of the many nematode species that parasitize citrus, Tylenchulus semipenetrans is the most important on a worldwide basis. Management of the citrus nematode remains problematic as no one tactic gives adequate control of the nematode. An overall management strategy must include such components as site selection, use of non-infected nursery stock, use of at lease one post-plant nematode control tactic, and careful ma