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Sample records for endobacteria-free filarial nematodes

  1. Discovery of filarial nematode DNA in Amblyomma americanum in Northern Virginia.

    Science.gov (United States)

    Henning, Tyler C; Orr, John M; Smith, Joshua D; Arias, Jorge R; Rasgon, Jason L; Norris, Douglas E

    2016-03-01

    Ticks collected in 2011 were screened for the presence of filarial nematode genetic material, and positive samples were sequenced for analysis. Monanema-like filarial nematode DNA was recently discovered in Amblyomma americanum in northern Virginia, marking the first time genetic material from this parasite has been discovered in ticks in the state. Phylogenetic analysis revealed that this material was directly related to a previously discovered filarial nematode in A. americanum populations in Maryland as well as recently identified parasites in Ixodes scapularis from southern Connecticut. Further study is warranted to visually confirm the presence of these nematodes, characterize their distribution, and determine if these ticks are intermediate hosts. Copyright © 2015 Elsevier GmbH. All rights reserved.

  2. Diversity, Host Specialization, and Geographic Structure of Filarial Nematodes Infecting Malagasy Bats.

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    Beza Ramasindrazana

    Full Text Available We investigated filarial infection in Malagasy bats to gain insights into the diversity of these parasites and explore the factors shaping their distribution. Samples were obtained from 947 individual bats collected from 52 sites on Madagascar and representing 31 of the 44 species currently recognized on the island. Samples were screened for the presence of micro- and macro-parasites through both molecular and morphological approaches. Phylogenetic analyses showed that filarial diversity in Malagasy bats formed three main groups, the most common represented by Litomosa spp. infecting Miniopterus spp. (Miniopteridae; a second group infecting Pipistrellus cf. hesperidus (Vespertilionidae embedded within the Litomosoides cluster, which is recognized herein for the first time from Madagascar; and a third group composed of lineages with no clear genetic relationship to both previously described filarial nematodes and found in M. griveaudi, Myotis goudoti, Neoromicia matroka (Vespertilionidae, Otomops madagascariensis (Molossidae, and Paratriaenops furculus (Hipposideridae. We further analyzed the infection rates and distribution pattern of Litomosa spp., which was the most diverse and prevalent filarial taxon in our sample. Filarial infection was disproportionally more common in males than females in Miniopterus spp., which might be explained by some aspect of roosting behavior of these cave-dwelling bats. We also found marked geographic structure in the three Litomosa clades, mainly linked to bioclimatic conditions rather than host-parasite associations. While this study demonstrates distinct patterns of filarial nematode infection in Malagasy bats and highlights potential drivers of associated geographic distributions, future work should focus on their alpha taxonomy and characterize arthropod vectors.

  3. Diversity, Host Specialization, and Geographic Structure of Filarial Nematodes Infecting Malagasy Bats

    Science.gov (United States)

    Ramasindrazana, Beza; Dellagi, Koussay; Lagadec, Erwan; Randrianarivelojosia, Milijaona; Goodman, Steven M.; Tortosa, Pablo

    2016-01-01

    We investigated filarial infection in Malagasy bats to gain insights into the diversity of these parasites and explore the factors shaping their distribution. Samples were obtained from 947 individual bats collected from 52 sites on Madagascar and representing 31 of the 44 species currently recognized on the island. Samples were screened for the presence of micro- and macro-parasites through both molecular and morphological approaches. Phylogenetic analyses showed that filarial diversity in Malagasy bats formed three main groups, the most common represented by Litomosa spp. infecting Miniopterus spp. (Miniopteridae); a second group infecting Pipistrellus cf. hesperidus (Vespertilionidae) embedded within the Litomosoides cluster, which is recognized herein for the first time from Madagascar; and a third group composed of lineages with no clear genetic relationship to both previously described filarial nematodes and found in M. griveaudi, Myotis goudoti, Neoromicia matroka (Vespertilionidae), Otomops madagascariensis (Molossidae), and Paratriaenops furculus (Hipposideridae). We further analyzed the infection rates and distribution pattern of Litomosa spp., which was the most diverse and prevalent filarial taxon in our sample. Filarial infection was disproportionally more common in males than females in Miniopterus spp., which might be explained by some aspect of roosting behavior of these cave-dwelling bats. We also found marked geographic structure in the three Litomosa clades, mainly linked to bioclimatic conditions rather than host-parasite associations. While this study demonstrates distinct patterns of filarial nematode infection in Malagasy bats and highlights potential drivers of associated geographic distributions, future work should focus on their alpha taxonomy and characterize arthropod vectors. PMID:26751792

  4. Shaking the Tree: Multi-locus Sequence Typing Usurps Current Onchocercid (Filarial Nematode) Phylogeny

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    Lefoulon, Emilie; Bourret, Jérôme; Junker, Kerstin; Guerrero, Ricardo; Cañizales, Israel; Kuzmin, Yuriy; Satoto, Tri Baskoro T.; Cardenas-Callirgos, Jorge Manuel; de Souza Lima, Sueli; Raccurt, Christian; Mutafchiev, Yasen; Gavotte, Laurent; Martin, Coralie

    2015-01-01

    During the past twenty years, a number of molecular analyses have been performed to determine the evolutionary relationships of Onchocercidae, a family of filarial nematodes encompassing several species of medical or veterinary importance. However, opportunities for broad taxonomic sampling have been scarce, and analyses were based mainly on 12S rDNA and coxI gene sequences. While being suitable for species differentiation, these mitochondrial genes cannot be used to infer phylogenetic hypotheses at higher taxonomic levels. In the present study, 48 species, representing seven of eight subfamilies within the Onchocercidae, were sampled and sequences of seven gene loci (nuclear and mitochondrial) analysed, resulting in the hitherto largest molecular phylogenetic investigation into this family. Although our data support the current hypothesis that the Oswaldofilariinae, Waltonellinae and Icosiellinae subfamilies separated early from the remaining onchocercids, Setariinae was recovered as a well separated clade. Dirofilaria, Loxodontofilaria and Onchocerca constituted a strongly supported clade despite belonging to different subfamilies (Onchocercinae and Dirofilariinae). Finally, the separation between Splendidofilariinae, Dirofilariinae and Onchocercinae will have to be reconsidered. PMID:26588229

  5. Lipoprotein biosynthesis as a target for anti-Wolbachia treatment of filarial nematodes

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    Slatko Barton E

    2010-10-01

    Full Text Available Abstract Background Lymphatic filariasis and onchocerciasis are debilitating diseases caused by filarial nematodes. Disease pathogenesis is induced by inflammatory responses following the death of the parasite. Wolbachia endosymbionts of filariae are potent inducers of innate and adaptive inflammation and bacterial lipoproteins have been identified as the ligands that bind toll-like receptors (TLR 2 and TLR6. Lipoproteins are important structural and functional components of bacteria and therefore enzymes involved in Wolbachia lipoprotein biosynthesis are potential chemotherapeutic targets. Results Globomycin, a signal peptidase II (LspA inhibitor, has activity against Gram-negative bacteria and a putative lspA gene has been identified from the Wolbachia genome of Brugia malayi (wBm. The amino acids required for function are strictly conserved and functionality was verified by complementation tests in a temperature-sensitive Escherichia coli lspA mutant. Also, transformation of wild type E. coli with Wolbachia lspA conferred significant globomycin resistance. A cell-based screen has been developed utilizing a Wolbachia-containing Aedes albopictus cell line to assay novel compounds active against Wolbachia. Globomycin was screened using this assay, which resulted in a dose-dependent reduction in Wolbachia load. Furthermore, globomycin was also effective in reducing the motility and viability of adult B. malayi in vitro. Conclusions These studies validate lipoprotein biosynthesis as a target in an organism for which no genetic tools are available. Further studies to evaluate drugs targeting this pathway are underway as part of the A-WOL drug discovery and development program.

  6. Detection and molecular characterization of the mosquito-borne filarial nematode Setaria tundra in Danish roe deer (Capreolus capreolus)

    DEFF Research Database (Denmark)

    Enemark, Heidi Larsen; Oksanen, Antti; Chriél, Mariann

    2017-01-01

    Setaria tundra is a mosquito-borne filarial nematode of cervids in Europe. It has recently been associated with an emerging epidemic disease causing severe morbidity and mortality in reindeer and moose in Finland. Here, we present the first report of S. tundra in six roe deer (Capreolus capreolus...... capsule, worms (ranging from 2 to >20/deer) were found free in the peritoneal cavity. The worms were identified as S. tundra by morphological examination and/or molecular typing of the mitochondrial 12S rRNA and cox1 genes, which showed 99.1-99.8% identity to previously published S. tundra isolates from...... for development of parasite larvae in the mosquito vectors are expected, which may lead to increasing prevalence of S. tundra. Monitoring of this vector-borne parasite may thus be needed in order to enhance the knowledge of factors promoting its expansion and prevalence as well as predicting disease outbreaks. (C...

  7. Immune recognition of excretory and secretory products of the filarial nematode Onchocerca ochengi in cattle and human sera.

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    Djafsia, B; Ndjonka, D; Dikti, J V; van Hoorn, S; Manchang, K; Brattig, N; Liebau, E

    2015-09-11

    Excretory-secretory (ES) products of nematodes and other helminths are the first molecules to interact with cell surfaces and soluble proteins within the host. In the present study, ES products of the filarial nematode Onchocerca ochengi were investigated as a model for Onchocerca volvulus, the causative agent of river blindness. These products were collected from adult and larval stages in vitro over a period of 7 days, to compare their immunological recognition in cattle and human sera, infected with species of Onchocerca. From the 156 sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) ES products or extracts, protein bands showed different patterns between female and male products. A comparison of antibody recognition of the different ES products by sera from infected cattle and humans, when analysed by enzyme-linked immunosorbent assay (ELISA), revealed a relatively higher reactivity of the female somatic extract to human and cattle sera compared to ES products of both genders. Nevertheless, similar reactivity of the O. ochengi male and female ES products to human and cattle sera was noticed. As a result, the interaction of ES products with the surface of the host and immune system often led to host responses, including the generation of antibodies. The O. ochengi ES products are therefore good sources of potential immunogenic proteins. The identification of these ES products is in progress, with the aim of developing vaccine candidates against human onchocerciasis.

  8. Detection and molecular characterization of the mosquito-borne filarial nematode Setaria tundra in Danish roe deer (Capreolus capreolus).

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    Enemark, Heidi Larsen; Oksanen, Antti; Chriél, Mariann; le Fèvre Harslund, Jakob; Woolsey, Ian David; Al-Sabi, Mohammad Nafi Solaiman

    2017-04-01

    Setaria tundra is a mosquito-borne filarial nematode of cervids in Europe. It has recently been associated with an emerging epidemic disease causing severe morbidity and mortality in reindeer and moose in Finland. Here, we present the first report of S. tundra in six roe deer ( Capreolus capreolus ) collected between October 2010 and March 2014 in Denmark. The deer originated from various localities across the country: the eastern part of the Jutland peninsular and four locations on the island Zealand. With the exception of one deer, with parasites residing in a transparent cyst just under the liver capsule, worms (ranging from 2 to >20/deer) were found free in the peritoneal cavity. The worms were identified as S. tundra by morphological examination and/or molecular typing of the mitochondrial 12S rRNA and cox1 genes, which showed 99.1-99.8% identity to previously published S. tundra isolates from Europe. Roe deer are generally considered as asymptomatic carriers and their numbers in Denmark have increased significantly in recent decades. In light of climatic changes which result in warmer, more humid weather in Scandinavia greater numbers of mosquitoes and, especially, improved conditions for development of parasite larvae in the mosquito vectors are expected, which may lead to increasing prevalence of S. tundra . Monitoring of this vector-borne parasite may thus be needed in order to enhance the knowledge of factors promoting its expansion and prevalence as well as predicting disease outbreaks.

  9. Detection and molecular characterization of the mosquito-borne filarial nematode Setaria tundra in Danish roe deer (Capreolus capreolus

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    Heidi Larsen Enemark

    2017-04-01

    Full Text Available Setaria tundra is a mosquito-borne filarial nematode of cervids in Europe. It has recently been associated with an emerging epidemic disease causing severe morbidity and mortality in reindeer and moose in Finland. Here, we present the first report of S. tundra in six roe deer (Capreolus capreolus collected between October 2010 and March 2014 in Denmark. The deer originated from various localities across the country: the eastern part of the Jutland peninsular and four locations on the island Zealand. With the exception of one deer, with parasites residing in a transparent cyst just under the liver capsule, worms (ranging from 2 to >20/deer were found free in the peritoneal cavity. The worms were identified as S. tundra by morphological examination and/or molecular typing of the mitochondrial 12S rRNA and cox1 genes, which showed 99.1–99.8% identity to previously published S. tundra isolates from Europe. Roe deer are generally considered as asymptomatic carriers and their numbers in Denmark have increased significantly in recent decades. In light of climatic changes which result in warmer, more humid weather in Scandinavia greater numbers of mosquitoes and, especially, improved conditions for development of parasite larvae in the mosquito vectors are expected, which may lead to increasing prevalence of S. tundra. Monitoring of this vector-borne parasite may thus be needed in order to enhance the knowledge of factors promoting its expansion and prevalence as well as predicting disease outbreaks.

  10. New insights into the evolution of Wolbachia infections in filarial nematodes inferred from a large range of screened species.

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    Emanuele Ferri

    Full Text Available Wolbachia are intriguing symbiotic endobacteria with a peculiar host range that includes arthropods and a single nematode family, the Onchocercidae encompassing agents of filariases. This raises the question of the origin of infection in filariae. Wolbachia infect the female germline and the hypodermis. Some evidences lead to the theory that Wolbachia act as mutualist and coevolved with filariae from one infection event: their removal sterilizes female filariae; all the specimens of a positive species are infected; Wolbachia are vertically inherited; a few species lost the symbiont. However, most data on Wolbachia and filaria relationships derive from studies on few species of Onchocercinae and Dirofilariinae, from mammals.We investigated the Wolbachia distribution testing 35 filarial species, including 28 species and 7 genera and/or subgenera newly screened, using PCR, immunohistochemical staining, whole mount fluorescent analysis, and cocladogenesis analysis. (i Among the newly screened Onchocercinae from mammals eight species harbour Wolbachia but for some of them, bacteria are absent in the hypodermis, or in variable density. (ii Wolbachia are not detected in the pathological model Monanema martini and in 8, upon 9, species of Cercopithifilaria. (iii Supergroup F Wolbachia is identified in two newly screened Mansonella species and in Cercopithifilaria japonica. (iv Type F Wolbachia infect the intestinal cells and somatic female genital tract. (v Among Oswaldofilariinae, Waltonellinae and Splendidofilariinae, from saurian, anuran and bird respectively, Wolbachia are not detected.The absence of Wolbachia in 63% of onchocercids, notably in the ancestral Oswaldofilariinae estimated 140 mya old, the diverse tissues or specimens distribution, and a recent lateral transfer in supergroup F Wolbachia, modify the current view on the role and evolution of the endosymbiont and their hosts. Further genomic analyses on some of the newly sampled species

  11. Both asymmetric mitotic segregation and cell-to-cell invasion are required for stable germline transmission of Wolbachia in filarial nematodes

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    Frédéric Landmann

    2012-04-01

    Parasitic filarial nematodes that belong to the Onchocercidae family live in mutualism with Wolbachia endosymbionts. We developed whole-mount techniques to follow the segregation patterns of Wolbachia through the somatic and germline lineages of four filarial species. These studies reveal multiple evolutionarily conserved mechanisms that are required for Wolbachia localization to the germline. During the initial embryonic divisions, Wolbachia segregate asymmetrically such that they concentrate in the posteriorly localized P2 blastomere, a precursor to the adult germline and hypodermal lineages. Surprisingly, in the next division they are excluded from the germline precursor lineage. Rather, they preferentially segregate to the C blastomere, a source of posterior hypodermal cells. Localization to the germline is accomplished by a distinct mechanism in which Wolbachia invade first the somatic gonadal cells close to the ovarian distal tip cell, the nematode stem cell niche, from the hypodermis. This tropism is associated with a cortical F-actin disruption, suggesting an active engulfment. Significantly, germline invasion occurs only in females, explaining the lack of Wolbachia in the male germline. Once in the syncytial environment of the ovaries, Wolbachia rely on the rachis to multiply and disperse into the germ cells. The utilization of cell-to-cell invasion for germline colonization may indicate an ancestral mode of horizontal transfer that preceded the acquisition of the mutualism.

  12. A Target Repurposing Approach Identifies N-myristoyltransferase as a New Candidate Drug Target in Filarial Nematodes

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    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

  13. A novel filarial topoisomerase II inhibitor produced by native ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-14

    Nov 14, 2011 ... Even though the disease is not fatal, the disabling occurring in chronic state is a cause of social stigma. Filariasis is a vector borne disease caused by the nematode Wuchereria ... topo II and they are reported as anti filarial or anti cancer drugs, still the emergence of such type of drug from the natural source ...

  14. Diminished IL-17A levels may protect filarial-infected individuals from development of rheumatoid arthritis and systemic lupus erythematosus.

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    Panda, A K; Das, B K

    2017-04-01

    Nematode infections have been observed to inversely correlate with autoimmune disorders. Recently, we have shown the absence of filarial infection in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) who live in filarial-endemic areas. The mechanism(s) by which filarial-infected individuals are protected against the development of RA or SLE are unknown. In mice CIA, an experimental model for RA, ES-62, an execratory product of rodent filarial nematode , has been shown to improve arthritis through suppression of the IL-17 pathway. A total of 160 individuals, 40 each of endemic normal, filarial-infected cases, SLE and RA patients, from filarial-endemic areas, were enrolled in the study. Plasma levels of IL17-A, IFN-α and TNF-α were quantified by enzyme-linked immunosorbent assay (ELISA). RA and SLE patients displayed significantly higher plasma IL-17A, IFN-α and TNF-α levels compared to endemic normal and infected individuals. Furthermore, IL-17A levels were significantly low in participants with filarial infection compared to endemic controls ( p < 0.05). Interestingly, plasma IL-17A levels correlated inversely with circulating filarial antigen (CFA) ( p = 0.004, Spearman r = -0.51). Filarial infection was associated with low plasma IL-17A levels, a mechanism by which it possibly protects individuals in filarial-endemic areas from the development of autoimmune disorders like RA and SLE.

  15. Molecular evidence of curcumin-induced apoptosis in the filarial worm Setaria cervi.

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    Nayak, Ananya; Gayen, Prajna; Saini, Prasanta; Mukherjee, Niladri; Babu, Santi P Sinha

    2012-09-01

    Curcumin (diferuloyl methane) is a major curcuminoid from Curcuma longa that exhibits various pharmacological effects and has shown multiple beneficial activities. Our understanding of its anticarcinogenic and other activities occurring through curcumin-induced apoptosis in several cancer cells has greatly expanded in recent years. Lymphatic filariasis is a worldwide health problem causing global disability in humans and is caused by filarial nematodes. Development of efficient strategies to promote programmed cell death in filarial worms remains a key challenge for anti-filarial drug developing research and a crucial unmet medical need. In this study, we have taken molecular and biochemical approaches toward understanding the molecular basis for curcumin-mediated anti-filarial activity in the filarial nematode Setaria cervi. Results of MTT assay showed that curcumin causes a significant reduction in viability of Mf and adults and thus acts as a potent macro- and micro-filaricidal agent. Hoechst staining, TUNEL staining, showed several apoptotic nuclei in different parts of curcumin-treated adults. At 25 μM concentration it showed chromosomal DNA fragmentation in adult worms. Our results indicate that curcumin decreases protein and mRNA expression levels of anti-apoptotic gene ced-9 and enhances both the levels of pro-apoptotic genes ced-3 and ced-4 in a dose-dependent manner. All these observations ascertained the apoptogenicity of curcumin at a minimum concentration of 50 μM in this filarial worm. Furthermore, we showed that curcumin causes depletion of parasitic glutathione level, enhances the activities of glutathione S-transferase and superoxide dismutase and stimulates rapid generation of reactive oxygen species (ROS). Here, we present molecular evidence on curcumin-induced apoptosis in the filarial nematode S. cervi with probable involvement of ROS in a caspase-dependent manner.

  16. Survey on the Ability of Wolbachia to Control Human Viral, Protozoan, and Filarial Disease Pathogens

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    Garedaghi Yagoob

    2014-04-01

    Full Text Available Objective: Most human filarial nematode parasites and arthropods are hosts for a bacterial endosymbiont, Wolbachia. In filariasis, Wolbachia are required for normal development, fertility, and survival. However, in arthropods, Wolbachia are largely parasitic and can influence development and reproduction, but are generally not required for host survival. Materials and Methods: Due to their obligate nature in filarial parasites, Wolbachia have been a target for drug discovery initiatives using several approaches including diversity and focused library screening and genomic sequence analysis. Results: In vitro and in vivo anti-Wolbachia antibiotic treatments have been shown to have adulticidal activity, a long sought goal of filarial parasite drug discovery. In mosquitoes, it has been shown that the presence of Wolbachia can inhibit the transmission of certain viruses, such as dengue, chikungunya, yellow fever, West Nile, as well as the infectivity of the malaria-causing protozoan, Plasmodium and filarial nematodes. Conclusion: Wolbachia can cause a form of conditional sterility that can be used to suppress populations of mosquitoes and additional medically important insects. Thus, Wolbachia, a pandemic endosymbiont, offers great potential for elimination of a wide-variety of devastating human diseases.

  17. Mosquito infection responses to developing filarial worms.

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    Sara M Erickson

    2009-10-01

    Full Text Available Human lymphatic filariasis is a mosquito-vectored disease caused by the nematode parasites Wuchereria bancrofti, Brugia malayi and Brugia timori. These are relatively large roundworms that can cause considerable damage in compatible mosquito vectors. In order to assess how mosquitoes respond to infection in compatible mosquito-filarial worm associations, microarray analysis was used to evaluate transcriptome changes in Aedes aegypti at various times during B. malayi development. Changes in transcript abundance in response to the different stages of B. malayi infection were diverse. At the early stages of midgut and thoracic muscle cell penetration, a greater number of genes were repressed compared to those that were induced (20 vs. 8. The non-feeding, intracellular first-stage larvae elicited few differences, with 4 transcripts showing an increased and 9 a decreased abundance relative to controls. Several cecropin transcripts increased in abundance after parasites molted to second-stage larvae. However, the greatest number of transcripts changed in abundance after larvae molted to third-stage larvae and migrated to the head and proboscis (120 induced, 38 repressed, including a large number of putative, immunity-related genes (approximately 13% of genes with predicted functions. To test whether the innate immune system of mosquitoes was capable of modulating permissiveness to the parasite, we activated the Toll and Imd pathway controlled rel family transcription factors Rel1 and Rel2 (by RNA interference knockdown of the pathway's negative regulators Cactus and Caspar during the early stages of infection with B. malayi. The activation of either of these immune signaling pathways, or knockdown of the Toll pathway, did not affect B. malayi in Ae. aegypti. The possibility of LF parasites evading mosquito immune responses during successful development is discussed.

  18. Filarial worms reduce Plasmodium infectivity in mosquitoes.

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    Matthew T Aliota

    2011-02-01

    Full Text Available Co-occurrence of malaria and filarial worm parasites has been reported, but little is known about the interaction between filarial worm and malaria parasites with the same Anopheles vector. Herein, we present data evaluating the interaction between Wuchereria bancrofti and Anopheles punctulatus in Papua New Guinea (PNG. Our field studies in PNG demonstrated that An. punctulatus utilizes the melanization immune response as a natural mechanism of filarial worm resistance against invading W. bancrofti microfilariae. We then conducted laboratory studies utilizing the mosquitoes Armigeres subalbatus and Aedes aegypti and the parasites Brugia malayi, Brugia pahangi, Dirofilaria immitis, and Plasmodium gallinaceum to evaluate the hypothesis that immune activation and/or development by filarial worms negatively impact Plasmodium development in co-infected mosquitoes. Ar. subalbatus used in this study are natural vectors of P. gallinaceum and B. pahangi and they are naturally refractory to B. malayi (melanization-based refractoriness.Mosquitoes were dissected and Plasmodium development was analyzed six days after blood feeding on either P. gallinaceum alone or after taking a bloodmeal containing both P. gallinaceum and B. malayi or a bloodmeal containing both P. gallinaceum and B. pahangi. There was a significant reduction in the prevalence and mean intensity of Plasmodium infections in two species of mosquito that had dual infections as compared to those mosquitoes that were infected with Plasmodium alone, and was independent of whether the mosquito had a melanization immune response to the filarial worm or not. However, there was no reduction in Plasmodium development when filarial worms were present in the bloodmeal (D. immitis but midgut penetration was absent, suggesting that factors associated with penetration of the midgut by filarial worms likely are responsible for the observed reduction in malaria parasite infections.These results could have an

  19. GRANULOMATOUS FILARIAL ENCEPHALOMYELITIS CAUSED BY CHANDLERELLA QUISCALI IN A NORTHERN CRESTED CARACARA (CARACARA CHERIWAY).

    Science.gov (United States)

    Edwards, Erin E; Dangoudoubiyam, Sriveny; Hoppes, Sharman M; Porter, Brian F

    2017-03-01

    A northern crested caracara (Caracara cheriway) was presented after being found nonambulatory in a field. On physical examination, the bird had severe hind-limb paresis. The bird did not improve after 10 days of hospitalization and was euthanized. Histologic examination of the cerebrum and spinal cord revealed multiple adult filarial nematodes surrounded by granulomatous inflammation with several multinucleated giant cells. These parasites were confirmed to be Chandlerella quiscali with polymerase chain reaction. This is the first report of C. quiscali in a bird of prey.

  20. Filarial hydrocele: a neglected condition of a neglected tropical disease.

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    Otabil, Kenneth Bentum; Tenkorang, Seth Boateng

    2015-03-18

    Filarial hydrocele is the most common chronic manifestation of lymphatic filariasis (LF) and poses a major public health burden to several filarial endemic countries. This review highlights the socio-economic impact of the disease, the role of the immune system in hydrocele development, current diagnostic approaches, and the control and management of filarial hydrocele. In the quest to facilitate the global effort to eliminate filarial hydrocele as a neglected tropical disease, a more comprehensive understanding of the mechanisms underlying the pathogenesis and development of the condition is important. In general, success has been achieved using annual treatment with ivermectin, but much remains to be done, particularly with late-stage infected individuals where surgery remains the only option. Studies have successfully demonstrated that inhibition of embryogenesis in adult female worms occurs after weeks of tetracycline treatment. Even more intriguing was the observation that the Wolbachia endosymbionts potently induce proinflammatory cytokines such as tumor necrosis factors (TNFs) and vascular endothelial growth factors (VEGFs), which are crucial for the development of filarial hydrocele. Furthermore, reports from human studies show that doxycycline treatment significantly ameliorates filarial hydrocele and markedly reverses early-stage filarial hydrocele. However, with the enormous challenges that face LF elimination such as global funding, logistics, civil wars, and drug resistance, a more relentless and collective approach from local governments as well as other stakeholders is needed to accelerate the fight against filarial hydrocele if the goal to eliminate it by 2020 is be to achieved.

  1. A Clinico- Epidemiological Study Of Filarial Related Orthopaedic Manifestations

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    Patond K.R

    1992-01-01

    Full Text Available An epidemiological study was undertaken to study the incidence and distribution of orthopaedic manifestations of filariasis in an endemic area. A total of 207 cases were clinically examined and investigated. Patients were divided into three groups , viz., Group A: Orthopaedic manifestations with no history of filariasis . Group B: Orthopaedic manifestations with history of filariasis such as microfilaraemia or filarial fevers etc., Group C: Orthopaedic manifestations with chronic manifestations such as elephantiasis, hydrocele etc. To confirm filarial etiology, all the cases were examined for the presence of filarial antibody by indirect ELISA using wuchereda bancrofti microfilarial excretory- secretary antigen (wd Mf ESAg . A total of 61 of 102 patients of Group A, 14 of 21 patients of group B, and 73 of 84 patients of Group C were positive for filarial antibody. This study showed the prevalence of filarial antibody in about 71.4% of various orthopaedic manifestations.

  2. Filarial infection caused by Onchocerca boehmi (Supperer, 1953) in a horse from Italy.

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    Lia, Riccardo Paolo; Mutafchiev, Yasen; Veneziano, Vincenzo; Giannelli, Alessio; Abramo, Francesca; Santoro, Mario; Latrofa, Maria Stefania; Cantacessi, Cinzia; Martin, Coralie; Otranto, Domenico; Bertuglia, Andrea; Riccio, Barbara

    2017-01-01

    Equids can be infected by a range of skin-dwelling filarial nematodes, including four species of the genus Onchocerca. Current literature on equine onchocercosis is fragmentary and often limited to isolated case reports. The present study aimed to describe a clinical case of equine onchocercosis caused by Onchocerca boehmi (Supperer, 1953) (syn. Elaeophora boehmi) in an 8-year-old gelding Belgian show jumper from northern Italy. The horse was presented with a firm and painless mass on the proximal third of the right metacarpal region. Ultrasound examination showed a peritendinous enlargement around the palmaro-lateral area of the tendons, characterized by an elongated hypoechoic and well-defined structure, embedding a coiled hyperechoic line. The metacarpal nodule was resected and histologically examined. Fragments of a parasitic nematode were detected, isolated and examined. The morphological analysis allowed identifying the nematode as O. boehmi. In addition, total genomic DNA was extracted from individual fragments using a commercial kit for the nematode identification and a comparative sequence analysis of the nematode cytochrome oxidase subunit 1 (cox1) sequence with data available in the GenBank TM database revealed the closest identity (i.e. 91 %) with that of Onchocerca lupi. Thus far, O. boehmi has only been reported in Austria and Iran, and information about its life-cycle and vectors is lacking. The systematic position of this species within the genus Onchocerca, not in Elaeophora where it was originally described, is in concordance with the morphological and molecular analysis. In this article, we describe the first autochthonous case of equine onchocercosis in Italy caused by O. boehmi and discuss novel parasitological, clinical, and pathological data on these pathogens of horses.

  3. The heme biosynthetic pathway of the obligate Wolbachia endosymbiont of Brugia malayi as a potential anti-filarial drug target.

    Directory of Open Access Journals (Sweden)

    Bo Wu

    2009-07-01

    Full Text Available 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.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 approximately 600-fold difference in drug sensitivities to succinyl acetone (SA between Wolbachia and human 5

  4. Identification of anti-filarial leads against aspartate semialdehyde dehydrogenase of Wolbachia endosymbiont of Brugia malayi: combined molecular docking and molecular dynamics approaches.

    Science.gov (United States)

    Amala, Mathimaran; Rajamanikandan, Sundaraj; Prabhu, Dhamodharan; Surekha, Kanagarajan; Jeyakanthan, Jeyaraman

    2018-02-06

    Lymphatic filariasis is a debilitating vector borne parasitic disease that infects human lymphatic system by nematode Brugia malayi. Currently available anti-filarial drugs are effective only on the larval stages of parasite. So far, no effective drugs are available for humans to treat filarial infections. In this regard, aspartate semialdehyde dehydrogenase (ASDase) in lysine biosynthetic pathway from Wolbachia endosymbiont Brugia malayi represents an attractive therapeutic target for the development of novel anti-filarial agents. In this present study, molecular modeling combined with molecular dynamics simulations and structure-based virtual screening were performed to identify potent lead molecules against ASDase. Based on Glide score, toxicity profile, binding affinity and mode of interactions with the ASDase, five potent lead molecules were selected. The molecular docking and dynamics results revealed that the amino acid residues Arg103, Asn133, Cys134, Gln161, Ser164, Lys218, Arg239, His246, and Asn321 plays a crucial role in effective binding of Top leads into the active site of ASDase. The stability of the ASDase-lead complexes was confirmed by running the 30 ns molecular dynamics simulations. The pharmacokinetic properties of the identified lead molecules are in the acceptable range. Furthermore, density functional theory and binding free energy calculations were performed to rank the lead molecules. Thus, the identified lead molecules can be used for the development of anti-filarial agents to combat the pathogenecity of Brugia malayi.

  5. Palaeosymbiosis revealed by genomic fossils of Wolbachia in a strongyloidean nematode.

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    Georgios Koutsovoulos

    2014-06-01

    Full Text Available Wolbachia are common endosymbionts of terrestrial arthropods, and are also found in nematodes: the animal-parasitic filaria, and the plant-parasite Radopholus similis. Lateral transfer of Wolbachia DNA to the host genome is common. We generated a draft genome sequence for the strongyloidean nematode parasite Dictyocaulus viviparus, the cattle lungworm. In the assembly, we identified nearly 1 Mb of sequence with similarity to Wolbachia. The fragments were unlikely to derive from a live Wolbachia infection: most were short, and the genes were disabled through inactivating mutations. Many fragments were co-assembled with definitively nematode-derived sequence. We found limited evidence of expression of the Wolbachia-derived genes. The D. viviparus Wolbachia genes were most similar to filarial strains and strains from the host-promiscuous clade F. We conclude that D. viviparus was infected by Wolbachia in the past, and that clade F-like symbionts may have been the source of filarial Wolbachia infections.

  6. Observations on Filarial Infection in Amassoma Community in the ...

    African Journals Online (AJOL)

    Three of the five mosquito spp collected from the community hardboured microfilariae: Anopheles gambiae (9.5%), A- funestus (6.6%), Culex quinquefestus (4.1%), Anopheles nili (-%), Aedes aegypti (0%). The presence of the microfilariae confirms that filarial infections in the study area are endemic. Entomological survey ...

  7. A novel filarial topoisomerase II inhibitor produced by native isolate ...

    African Journals Online (AJOL)

    A novel inhibitor of filarial topoisomerase II was isolated from the culture filtrate of native isolate Micrococcus luteus B1252. The methanolic extract of the cell pellet was partially purified by silica column chromatography and preparative high performance liquid chromatography (HPLC). The active fraction obtained from HPLC ...

  8. Vulvar Filarial Elephantiasis in A Tanzanian Woman; Rare ...

    African Journals Online (AJOL)

    Lymphatic filariasis is frequently caused by Wuchereria banchrofti a widely distributed filarial worm throughout tropical regions of Asia and Africa. This worm is particularly prevalent in wet and humid areas. The common clinical manifestations of Banchroftian filariasis are acute adenolymphangitis, hydrocele, lymphedema ...

  9. Phytopathogenic Nematodes

    NARCIS (Netherlands)

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

    2015-01-01

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

  10. Absence of Wolbachia endobacteria in the non-filariid nematodes Angiostrongylus cantonensis and A. costaricensis

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    Graeff-Teixeira Carlos

    2008-09-01

    Full Text Available Abstract The majority of filarial nematodes harbour Wolbachia endobacteria, including the major pathogenic species in humans, Onchocerca volvulus, Brugia malayi and Wuchereria bancrofti. These obligate endosymbionts have never been demonstrated unequivocally in any non-filariid nematode. However, a recent report described the detection by PCR of Wolbachia in the metastrongylid nematode, Angiostrongylus cantonensis (rat lungworm, a leading cause of eosinophilic meningitis in humans. To address the intriguing possibility of Wolbachia infection in nematode species distinct from the Family Onchocercidae, we used both PCR and immunohistochemistry to screen samples of A. cantonensis and A. costaricensis for the presence of this endosymbiont. We were unable to detect Wolbachia in either species using these methodologies. In addition, bioinformatic and phylogenetic analyses of the Wolbachia gene sequences reported previously from A. cantonensis indicate that they most likely result from contamination with DNA from arthropods and filarial nematodes. This study demonstrates the need for caution in relying solely on PCR for identification of new endosymbiont strains from invertebrate DNA samples.

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

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    Uni S.

    2006-09-01

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

  12. Interleukin-4 activated macrophages mediate immunity to filarial helminth infection by sustaining CCR3-dependent eosinophilia.

    Science.gov (United States)

    Turner, Joseph D; Pionnier, Nicolas; Furlong-Silva, Julio; Sjoberg, Hanna; Cross, Stephen; Halliday, Alice; Guimaraes, Ana F; Cook, Darren A N; Steven, Andrew; Van Rooijen, Nico; Allen, Judith E; Jenkins, Stephen J; Taylor, Mark J

    2018-03-01

    Eosinophils are effectors in immunity to tissue helminths but also induce allergic immunopathology. Mechanisms of eosinophilia in non-mucosal tissues during infection remain unresolved. Here we identify a pivotal function of tissue macrophages (Mϕ) in eosinophil anti-helminth immunity using a BALB/c mouse intra-peritoneal Brugia malayi filarial infection model. Eosinophilia, via C-C motif chemokine receptor (CCR)3, was necessary for immunity as CCR3 and eosinophil impairments rendered mice susceptible to chronic filarial infection. Post-infection, peritoneal Mϕ populations proliferated and became alternatively-activated (AAMϕ). Filarial AAMϕ development required adaptive immunity and interleukin-4 receptor-alpha. Depletion of Mϕ prior to infection suppressed eosinophilia and facilitated worm survival. Add back of filarial AAMϕ in Mϕ-depleted mice recapitulated a vigorous eosinophilia. Transfer of filarial AAMϕ into Severe-Combined Immune Deficient mice mediated immunological resistance in an eosinophil-dependent manner. Exogenous IL-4 delivery recapitulated tissue AAMϕ expansions, sustained eosinophilia and mediated immunological resistance in Mϕ-intact SCID mice. Co-culturing Brugia with filarial AAMϕ and/or filarial-recruited eosinophils confirmed eosinophils as the larvicidal cell type. Our data demonstrates that IL-4/IL-4Rα activated AAMϕ orchestrate eosinophil immunity to filarial tissue helminth infection.

  13. Chronic filarial infection provides protection against bacterial sepsis by functionally reprogramming macrophages.

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    Fabian Gondorf

    2015-01-01

    Full Text Available Helminths immunomodulate their hosts and induce a regulatory, anti-inflammatory milieu that prevents allergies and autoimmune diseases. Helminth immunomodulation may benefit sepsis outcome by preventing exacerbated inflammation and severe pathology, but the influence on bacterial clearance remains unclear. To address this, mice were chronically infected with the filarial nematode Litomosoides sigmodontis (L.s. and the outcome of acute systemic inflammation caused by i.p. Escherichia coli injection was determined. L.s. infection significantly improved E. coli-induced hypothermia, bacterial clearance and sepsis survival and correlated with reduced concentrations of associated pro-inflammatory cytokines/chemokines and a less pronounced pro-inflammatory macrophage gene expression profile. Improved sepsis outcome in L.s.-infected animals was mediated by macrophages, but independent of the alternatively activated macrophage subset. Endosymbiotic Wolbachia bacteria that are present in most human pathogenic filariae, as well as L.s., signal via TLR2 and modulate macrophage function. Here, gene expression profiles of peritoneal macrophages from L.s.-infected mice revealed a downregulation of genes involved in TLR signaling, and pulsing of macrophages in vitro with L.s. extract reduced LPS-triggered activation. Subsequent transfer improved sepsis outcome in naïve mice in a Wolbachia- and TLR2-dependent manner. In vivo, phagocytosis was increased in macrophages from L.s.-infected wild type, but not TLR2-deficient animals. In association, L.s. infection neither improved bacterial clearance in TLR2-deficient animals nor ameliorated E. coli-induced hypothermia and sepsis survival. These results indicate that chronic L.s. infection has a dual beneficial effect on bacterial sepsis, reducing pro-inflammatory immune responses and improving bacterial control. Thus, helminths and their antigens may not only improve the outcome of autoimmune and allergic diseases

  14. Detection of filarial antigen and antibody in serum and hydrocele fluid of 100 patients of hydrocele.

    Science.gov (United States)

    Goel, Ravishankar S; Verma, Nimesh S; Mullan, Sumaiya A; Ashdown, Andrew C

    2006-05-01

    The present study was carried out to detect an association between isolated non-communicable hydrocoele and filariasis and to provide awareness to positive patients regarding sequel and advising methods for the reduction of morbidity. Blood samples and hydrocoele fluids were used to detect filarial antigen and antibody by ICT Kit, Trop-bio kit and Sevafilachek Kit. These were followed by statistical evaluation by chi2 test. 14% of cases were positive for filarial antigen and antibody in hydrocoele patient serum, while 15% of cases were positive for filarial antigen and antibody in the serum of non-hydrocoele patients. Probability is less than 0.05, which is statistically significant.

  15. Unique structure and regulation of the nematode detoxification gene regulator SKN-1: implications to understanding and controlling drug resistance

    Science.gov (United States)

    Choe, Keith P.; Leung, Chi K.; Miyamoto, Michael M.

    2012-01-01

    Nematodes parasitize an alarming number of people and agricultural animals globally and cause debilitating morbidity and mortality. Anthelmintics have been the primary tools used to control parasitic nematodes for the past several decades, but drug resistance is becoming a major obstacle. Xenobiotic detoxification pathways defend against drugs and other foreign chemicals in diverse organisms, and evidence is accumulating that they play a role in mediating resistance to anthelmintics in nematodes. Related anti-oxidation pathways may also provide filarial parasites protection against host free radical-mediated immune responses. Upstream regulatory pathways have received almost no attention in nematode parasites despite their potential to co-regulate multiple detoxification and anti-oxidation genes. The NRF2 transcription factor mediates inducible detoxification and anti-oxidation defenses in mammals and recent studies have demonstrated that it promotes multidrug resistance in some human tumors. Recent studies in the free-living model nematode Caenorhabditis elegans have defined the homologous transcription factor SKN-1 as a master regulator of detoxification and anti-oxidation genes. Despite similar functions, SKN-1 and NRF2 have important differences in structure and regulatory pathways. Protein alignment and phylogenetic analyses indicate that these differences are shared among many nematodes making SKN-1 a candidate for specifically targeting nematode detoxification and anti-oxidation. PMID:22656429

  16. The Nematode Caenorhabditis Elegans.

    Science.gov (United States)

    Kenyon, Cynthia

    1988-01-01

    Discusses advantages of nematode use for studying patterns of cell division, differentiation, and morphogenesis. Describes nematode development. Cites experimental approaches available for genetic studies. Reviews the topics of control of cell division and differentiation, the nervous system, and muscle assembly and function of the organism. (RT)

  17. Nematode-Trapping Fungi.

    Science.gov (United States)

    Jiang, Xiangzhi; Xiang, Meichun; Liu, Xingzhong

    2017-01-01

    Nematode-trapping fungi are a unique and intriguing group of carnivorous microorganisms that can trap and digest nematodes by means of specialized trapping structures. They can develop diverse trapping devices, such as adhesive hyphae, adhesive knobs, adhesive networks, constricting rings, and nonconstricting rings. Nematode-trapping fungi have been found in all regions of the world, from the tropics to Antarctica, from terrestrial to aquatic ecosystems. They play an important ecological role in regulating nematode dynamics in soil. Molecular phylogenetic studies have shown that the majority of nematode-trapping fungi belong to a monophyletic group in the order Orbiliales (Ascomycota). Nematode-trapping fungi serve as an excellent model system for understanding fungal evolution and interaction between fungi and nematodes. With the development of molecular techniques and genome sequencing, their evolutionary origins and divergence, and the mechanisms underlying fungus-nematode interactions have been well studied. In recent decades, an increasing concern about the environmental hazards of using chemical nematicides has led to the application of these biological control agents as a rapidly developing component of crop protection.

  18. APPLICATION OF BIOTECHNOLOGY TO THE STUDY OF FILARIAL PARASITES AND THEIR VECTORS

    Directory of Open Access Journals (Sweden)

    A. C. Vickery

    2012-09-01

    Full Text Available Over 200 species of filarial parasites have been described, although the life cycle and nature of their obligate intermediate arthropod vectors have been identified for only about a quarter of them. Traditional methods of studying phylogenetic relationships between closely related parasite species have utilized morphologic, biochemical and biologic characteristics, usually of the microfilarial stage. Identification of competent vectors from among complexes of sibling species, has employed similar techniques, despite the fact that differences between geographical isolates may reflect environmental rather than genetically controlled factors. Studies of the prevalence and transmission of animal, human and zoonotic filarids, so important for vector identification and control, has lead to the examination of filarial parasites at the genetic level. Genomic DNA libraries are being constructed and screened for clones which are species specific. From this work, DNA probes which can accurately enumerate larval stages in vector squash preparations, and monoclonal antibodies specific for defined filarial antigens, are being prepared. The nucleotide sequences of rRNA are also being defined. The application of these technologies to the study of filarial parasites and their vectors, promises to not only allow the construction of accurate phylogenetic trees, but also to provide the data necessary for the identification and control of the vectors of filarial pathogens of animals and man.

  19. Finding Wolbachia in Filarial larvae and Culicidae Mosquitoes in Upper Egypt Governorate.

    Science.gov (United States)

    Dyab, Ahmed K; Galal, Lamia A; Mahmoud, Abeer E; Mokhtar, Yasser

    2016-06-01

    Wolbachia is an obligatory intracellular endosymbiotic bacterium, present in over 20% of all insects altering insect reproductive capabilities and in a wide range of filarial worms which is essential for worm survival and reproduction. In Egypt, no available data were found about Wolbachia searching for it in either mosquitoes or filarial worms. Thus, we aimed to identify the possible concurrent presence of Wolbachia within different mosquitoes and filarial parasites, in Assiut Governorate, Egypt using multiplex PCR. Initially, 6 pools were detected positive for Wolbachia by single PCR. The simultaneous detection of Wolbachia and filarial parasites (Wuchereria bancrofti, Dirofilaria immitis, and Dirofilaria repens) by multiplex PCR was spotted in 5 out of 6 pools, with an overall estimated rate of infection (ERI) of 0.24%. Unexpectedly, the highest ERI (0.53%) was for Anopheles pharoensis with related Wolbachia and W. bancrofti, followed by Aedes (0.42%) and Culex (0.26%). We also observed that Wolbachia altered Culex spp. as a primary vector for W. bancrofti to be replaced by Anopheles sp. Wolbachia within filaria-infected mosquitoes in our locality gives a hope to use bacteria as a new control trend simultaneously targeting the vector and filarial parasites.

  20. Analysis of nematode motion using an improved light-scatter based system.

    Directory of Open Access Journals (Sweden)

    Chuck S Nutting

    2015-02-01

    Full Text Available The detailed assessment of nematode activity and viability still remains a relatively undeveloped area of biological and medical research. Computer-based approaches to assessing the motility of larger nematode stages have been developed, yet these lack the capability to detect and analyze the more subtle and important characteristics of the motion of nematodes. There is currently a need to improved methods of assessing the viability and health of parasitic worms.We describe here a system that converts the motion of nematodes through a light-scattering system into an electrical waveform, and allows for reproducible, and wholly non-subjective, assessment of alterations in motion, as well as estimation of the number of nematode worms of different forms and sizes. Here we have used Brugia sp. microfilariae (L1, infective larvae (L3 and adults, together with the free-living nematode Caenorhabditis elegans.The motion of worms in a small (200 ul volume can be detected, with the presence of immotile worms not interfering with the readings at practical levels (up to at least 500 L1 /200 ul. Alterations in the frequency of parasite movement following the application of the anti-parasitic drugs, (chloroquine and imatinib; the anti-filarial effect of the latter agent is the first demonstrated here for the first time. This system can also be used to estimate the number of parasites, and shortens the time required to estimate parasites numbers, and eliminates the need for microscopes and trained technicians to provide an estimate of microfilarial sample sizes up to 1000 parasites/ml. Alterations in the form of motion of the worms can also be depicted.This new instrument, named a "WiggleTron", offers exciting opportunities to further study nematode biology and to aid drug discovery, as well as contributing to a rapid estimate of parasite numbers in various biological samples.

  1. A deep sequencing approach to comparatively analyze the transcriptome of lifecycle stages of the filarial worm, Brugia malayi.

    Directory of Open Access Journals (Sweden)

    Young-Jun Choi

    2011-12-01

    Full Text Available Developing intervention strategies for the control of parasitic nematodes continues to be a significant challenge. Genomic and post-genomic approaches play an increasingly important role for providing fundamental molecular information about these parasites, thus enhancing basic as well as translational research. Here we report a comprehensive genome-wide survey of the developmental transcriptome of the human filarial parasite Brugia malayi.Using deep sequencing, we profiled the transcriptome of eggs and embryos, immature (≤3 days of age and mature microfilariae (MF, third- and fourth-stage larvae (L3 and L4, and adult male and female worms. Comparative analysis across these stages provided a detailed overview of the molecular repertoires that define and differentiate distinct lifecycle stages of the parasite. Genome-wide assessment of the overall transcriptional variability indicated that the cuticle collagen family and those implicated in molting exhibit noticeably dynamic stage-dependent patterns. Of particular interest was the identification of genes displaying sex-biased or germline-enriched profiles due to their potential involvement in reproductive processes. The study also revealed discrete transcriptional changes during larval development, namely those accompanying the maturation of MF and the L3 to L4 transition that are vital in establishing successful infection in mosquito vectors and vertebrate hosts, respectively.Characterization of the transcriptional program of the parasite's lifecycle is an important step toward understanding the developmental processes required for the infectious cycle. We find that the transcriptional program has a number of stage-specific pathways activated during worm development. In addition to advancing our understanding of transcriptome dynamics, these data will aid in the study of genome structure and organization by facilitating the identification of novel transcribed elements and splice variants.

  2. Extraintestinal nematodes of the red fox Vulpes vulpes in north-west Italy.

    Science.gov (United States)

    Magi, M; Guardone, L; Prati, M C; Mignone, W; Macchioni, F

    2015-07-01

    Extraintestinal nematodes of the red fox (Vulpes vulpes) are a wide group of parasites that infect wild and domestic carnivores and occasionally humans. Nematodes in the cardiopulmonary system, stomach, urinary apparatus and muscle tissue of 165 red foxes (Vulpes vulpes) from north-west Italy (Liguria and Piedmont) were investigated between 2009 and 2012. Of the cardiopulmonary nematodes, a high prevalence of Angiostrongylus vasorum and Eucoleus aerophilus (syn. Capillaria aerophila) was found, 78.2% and 41.8% respectively; Crenosoma vulpis (15.8%) and Filaroides spp. (4.8%) were also found. Spirocerca lupi (23.5%), Aonchotheca putorii (syn. Capillaria putorii) (8.6%) and Physaloptera spp. (2.5%) were detected in the stomach and Pearsonema plica (syn. Capillaria plica) (56.8%) in the bladder. Eucoleus boehmi (syn. Capillaria boehmi) was also detected in the nasal cavities of one of the two foxes examined. A coprological examination revealed eggs of E. aerophilus, A. putorii, S. lupi, Physaloptera spp. and eggs of intestinal parasites. Filarial worms were absent in all the 165 animals examined, nor was there evidence of Trichinella spp. in any of the foxes. The foxes were found to host a high prevalence of many species of extraintestinal nematodes. The prevalence of A. vasorum in foxes found in the present study is among the highest in Europe. In addition, to the best of our knowledge, E. boehmi and Filaroides spp. have never been reported before in this host in Italy.

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

    Directory of Open Access Journals (Sweden)

    Sanjay Kumar

    Full Text Available 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.

  4. Inhibition of cathepsin B by E-64 induces oxidative stress and apoptosis in filarial parasite.

    Directory of Open Access Journals (Sweden)

    Mohit Wadhawan

    Full Text Available Current available antifilarial drug strategies only eliminate the larval stages of filarial parasites. Therefore, there is an urgent need of drugs which are macrofilaricidals. Identification of molecular targets crucial for survival of parasite is a prerequisite for drug designing. Cathepsin B, a cysteine protease family member is known to play crucial role in the normal growth, digestion of nutrients, exsheathment of the helminth parasites. Therefore, we targeted this enzyme in the filarial parasite using its specific inhibitor, E-64.We have exposed the parasites to E-64 and observed their motility and viability at various time intervals. It caused marked decrease in the motility and viability of the parasites ultimately leading to their death after 8 hours. It is well known that E-64 protects the cell from apoptosis, however, it causes apoptotic effect in carcinoma cell lines. To understand the mechanism of action of E-64 on parasite survival, we have measured levels of different apoptotic markers in the treated parasites. E-64 significantly reduced the level of ced-9 and activity of tyrosine phosphatases, cytochrome c oxidase. It also activated ced-3, homolog of mammalian caspase 3 suggesting initiation of an apoptotic like event in the filarial parasites. Different antioxidant enzymes were also evaluated to further explore the mechanism behind the death of the parasites. There was marked decrease in the level of GSH and activity of Glutathione reductase and glutathione-s-transferase leading to increased generation of reactive oxygen species. This led to the induced oxidation of fatty acids and protein which might alter the mitochondrial membrane permeability.This study suggests that inhibition of cathepsin B by E-64 generates oxidative stress followed by mitochondrial mediated apoptotic like event in filarial parasites leading to their death. Hence, suggesting filarial cathepsin B as a potential chemotherapeutic target for lymphatic

  5. Detection of anti-filarial antibody among hydrocele patients living in an endemic area for filariasis

    Directory of Open Access Journals (Sweden)

    Amit Kumar Singh

    2016-01-01

    Full Text Available Background: The knowledge of the current prevalence of lymphatic filariasis and its transmission will be helpful in its elimination. Thus, the present study is aimed to determine its prevalence among hydrocele patients which is a common presentation in chronically infected cases. Materials and Methods: One hundred patients suffering from hydrocele admitted to the surgical ward were included in the study. Blood samples were collected from the patients during the day hours for the detection of anti-filarial antibody and during night hours to detect the presence of microfilaria by smear examination. Blood samples were also collected from the family member attending the ward along with the patients to determine the presence of anti-filarial antibodies. Serum IgE level and eosinophil count were also determined in the patients showing a positive result for the anti-filarial antibody test. Results: Out of 100 hydrocele patients, 21% patients showed anti-filarial antibody card test positive with maximum patients belonging to age group of 20-40 years. Microfilaria was detected in 5% of the hydrocele patients, whereas none of the family members showed positive anti-filarial antibody test. Serum IgE level and eosinophil count were more than 1000 ng/ml and 500/mm 3 , respectively. Conclusions: The study has found a high prevalence of filariasis among hydrocele patients. It is suggested that more studies are needed to know the real time prevalence of the cases showing manifestations of the filariasis in the acute stage which will help the eradication program to formulate new strategies.

  6. Escherichia coli-induced immune paralysis is not exacerbated during chronic filarial infection.

    Science.gov (United States)

    Buerfent, Benedikt C; Gondorf, Fabian; Wohlleber, Dirk; Schumak, Beatrix; Hoerauf, Achim; Hübner, Marc P

    2015-05-01

    Sepsis initially starts with a systemic inflammatory response (SIRS phase) and is followed by a compensatory anti-inflammatory response syndrome (CARS) that causes impaired adaptive T-cell immunity, immune paralysis and an increased susceptibility to secondary infections. In contrast, parasitic filariae release thousands of microfilariae into the peripheral blood without triggering inflammation, as they induce regulatory, anti-inflammatory host responses. Hence, we investigated the impact of chronic filarial infection on adaptive T-cell responses during the SIRS and CARS phases of a systemic bacterial infection and analysed the development of T-cell paralysis following a subsequent adenovirus challenge in BALB/c mice. Chronic filarial infection impaired adenovirus-specific CD8(+) T-cell cytotoxicity and interferon-γ responses in the absence of a bacterial challenge and led to higher numbers of splenic CTLA-4(+)  CD4(+) T cells, whereas splenic T-cell expression of CD69 and CD62 ligand, serum cytokine levels and regulatory T-cell frequencies were comparable to naive controls. Irrespective of filarial infection, the SIRS phase dominated 6-24 hr after intravenous Escherichia coli challenge with increased T-cell activation and pro-inflammatory cytokine production, whereas the CARS phase occurred 6 days post E. coli challenge and correlated with high levels of transforming growth factor-β and increased CD62 ligand T-cell expression. Escherichia coli-induced impairment of adenovirus-specific CD8(+) T-cell cytotoxicity and interferon-γ production was not additionally impaired by chronic filarial infection. This suggests that filarial immunoregulation does not exacerbate E. coli-induced T-cell paralysis. © 2014 John Wiley & Sons Ltd.

  7. Detection of anti-filarial antibody among hydrocele patients living in an endemic area for filariasis

    Science.gov (United States)

    Singh, Amit Kumar; Agarwal, Loveleena; Lakhmani, Krishna; Sengupta, Chandrim; Singh, Ravinder Pal

    2016-01-01

    Background: The knowledge of the current prevalence of lymphatic filariasis and its transmission will be helpful in its elimination. Thus, the present study is aimed to determine its prevalence among hydrocele patients which is a common presentation in chronically infected cases. Materials and Methods: One hundred patients suffering from hydrocele admitted to the surgical ward were included in the study. Blood samples were collected from the patients during the day hours for the detection of anti-filarial antibody and during night hours to detect the presence of microfilaria by smear examination. Blood samples were also collected from the family member attending the ward along with the patients to determine the presence of anti-filarial antibodies. Serum IgE level and eosinophil count were also determined in the patients showing a positive result for the anti-filarial antibody test. Results: Out of 100 hydrocele patients, 21% patients showed anti-filarial antibody card test positive with maximum patients belonging to age group of 20–40 years. Microfilaria was detected in 5% of the hydrocele patients, whereas none of the family members showed positive anti-filarial antibody test. Serum IgE level and eosinophil count were more than 1000 ng/ml and 500/mm3, respectively. Conclusions: The study has found a high prevalence of filariasis among hydrocele patients. It is suggested that more studies are needed to know the real time prevalence of the cases showing manifestations of the filariasis in the acute stage which will help the eradication program to formulate new strategies. PMID:28217582

  8. Nematode cholinergic pharmacology

    Energy Technology Data Exchange (ETDEWEB)

    Segerberg, M.A.

    1989-01-01

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

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

    Science.gov (United States)

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

    2017-07-01

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

  10. Is there a risk of filarial infection during long-term missions in Haiti?

    Science.gov (United States)

    Weitzel, Thomas; Rosas, Reinaldo; Fica, Alberto; Dabanch, Jeannette; Polanco, Myriam; Egaña, Alicia; Triantafilo, Vjera; Pfarr, Kenneth; Hoerauf, Achim; Reiter-Owona, Ingrid

    2016-01-01

    Haiti has the highest prevalence of lymphatic filariasis (Wuchereria bancrofti) in the Western Hemisphere. Still, the risk of filarial infection for long-term visitors such as humanitarian aid workers or military personnel is uncertain. The presented study analyzed the exposure to W. bancrofti in Chilean participants of the UN Stabilization Mission in Haiti (MINUSTAH) in 2011. Blood samples collected from 531 participants were screened for antifilarial antibodies by IgG ELISA, and, if positive, analyzed by immunofluorescence assay (IFA), IgG4 ELISA, Real-Time PCR, and circulating filarial antigen (CFA) card test. ELISA screening was positive in 10 cases. Seroconversion occurred in only two cases (0.38%) based on ELISA values determined in samples taken before and after deployment. Positive IgG ELISA values could not be confirmed by IFA and IgG4 ELISA. Real-Time PCR and CFA testing did not reveal the presence of filaria. Our data indicate that in the examined cohort of MINUSTAH participants in 2011, the risk of filarial exposure or infection was low. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Circulating microbial products and acute phase proteins as markers of pathogenesis in lymphatic filarial disease.

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    R Anuradha

    Full Text Available Lymphatic filariasis can be associated with development of serious pathology in the form of lymphedema, hydrocele, and elephantiasis in a subset of infected patients. Dysregulated host inflammatory responses leading to systemic immune activation are thought to play a central role in filarial disease pathogenesis. We measured the plasma levels of microbial translocation markers, acute phase proteins, and inflammatory cytokines in individuals with chronic filarial pathology with (CP Ag+ or without (CP Ag- active infection; with clinically asymptomatic infections (INF; and in those without infection (endemic normal [EN]. Comparisons between the two actively infected groups (CP Ag+ compared to INF and those without active infection (CP Ag- compared to EN were used preliminarily to identify markers of pathogenesis. Thereafter, we tested for group effects among all the four groups using linear models on the log transformed responses of the markers. Our data suggest that circulating levels of microbial translocation products (lipopolysaccharide and LPS-binding protein, acute phase proteins (haptoglobin and serum amyloid protein-A, and inflammatory cytokines (IL-1β, IL-12, and TNF-α are associated with pathogenesis of disease in lymphatic filarial infection and implicate an important role for circulating microbial products and acute phase proteins.

  12. Social networks of educated nematodes

    Science.gov (United States)

    Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound...

  13. cyst nematode in tiaret a

    African Journals Online (AJOL)

    F. Labdelli

    1 sept. 2017 ... Syrie par [12], en Arabie saoudite par [16, 17], en Iran par [18] en Inde par [19]en Chine par[20] . .... qui a pour principe d'évaluer le taux de multiplication du nematode en fin de culture et le comparé à ..... cereal cyst nematode complex in relation to breeding resistant durum wheat Fundam. appl. Nemat ...

  14. RNA interference in plant parasitic nematodes

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-04

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

  15. Filarial granuloma of the testicular tunic mimicking a testicular neoplasm: a case report

    Directory of Open Access Journals (Sweden)

    Barreto Savio G

    2008-10-01

    Full Text Available Abstract Introduction Any firm or solid intratesticular mass on examination and/or any hypoechoic area within the tunica albuginea on imaging is markedly suspicious for testicular cancer. Filarial involvement of the testicular tunic has not been reported previously. Case presentation A 32-year-old man presented with a history of noticing a swelling in his right testicle for a period of 1 month which had become painful over the 10 days before presentation. Pre-operative imaging failed to shed light on the nature of the lesions (malignant or benign. The diagnostic dilemma was explained to the patient and informed consent was obtained for an orchiectomy. The patient underwent a high inguinal orchiectomy. The histopathology revealed a filarial granuloma of the testicular tunic. Conclusion While it is generally regarded that any testicular swelling, especially in a young person, should be treated as a malignancy unless proven otherwise, it is important to remember that infectious diseases such as filariasis and tuberculosis may mimic neoplasms. Careful consideration of these diagnoses must be given when dealing with testicular swellings especially in areas where the prevalence of these diseases is high.

  16. Eosinophils are important for protection, immunoregulation and pathology during infection with nematode microfilariae.

    Directory of Open Access Journals (Sweden)

    Emma T Cadman

    2014-03-01

    Full Text Available Eosinophil responses typify both allergic and parasitic helminth disease. In helminthic disease, the role of eosinophils can be both protective in immune responses and destructive in pathological responses. To investigate whether eosinophils are involved in both protection and pathology during filarial nematode infection, we explored the role of eosinophils and their granule proteins, eosinophil peroxidase (EPO and major basic protein-1 (MBP-1, during infection with Brugia malayi microfilariae. Using eosinophil-deficient mice (PHIL, we further clarify the role of eosinophils in clearance of microfilariae during primary, but not challenge infection in vivo. Deletion of EPO or MBP-1 alone was insufficient to abrogate parasite clearance suggesting that either these molecules are redundant or eosinophils act indirectly in parasite clearance via augmentation of other protective responses. Absence of eosinophils increased mast cell recruitment, but not other cell types, into the broncho-alveolar lavage fluid during challenge infection. In addition absence of eosinophils or EPO alone, augmented parasite-induced IgE responses, as measured by ELISA, demonstrating that eosinophils are involved in regulation of IgE. Whole body plethysmography indicated that nematode-induced changes in airway physiology were reduced in challenge infection in the absence of eosinophils and also during primary infection in the absence of EPO alone. However lack of eosinophils or MBP-1 actually increased goblet cell mucus production. We did not find any major differences in cytokine responses in the absence of eosinophils, EPO or MBP-1. These results reveal that eosinophils actively participate in regulation of IgE and goblet cell mucus production via granule secretion during nematode-induced pathology and highlight their importance both as effector cells, as damage-inducing cells and as supervisory cells that shape both innate and adaptive immunity.

  17. Circulating filarial antigen in serum and hydrocele fluid from individuals living in an endemic area for bancroftian filariasis

    Directory of Open Access Journals (Sweden)

    Shah A

    2007-01-01

    Full Text Available This study examined circulating filarial antigen by monoclonal antibody Og4C3-enzyme-linked immunosorbent assay (ELISA from 114 men with hydrocele, living in an endemic area. Nocturnal blood and hydrocele fluid were collected and examined for microfilaria. ELISA was performed on serum and hydrocele fluid for detection of antigen. Amongst 114 cases, 5(4.4% showed microfilaria in blood but none in fluid. ELISA was positive in 13(11.40% serum and 5 (4.4% fluid samples. All five fluid antigen positive cases were positive for antibodies and showed microfilaria in blood. These findings emphasize the use of circulating filarial antigen detection and alternative usage of hydrocele fluid for diagnosis of filariasis.

  18. In vitro, in silico and in vivo studies of ursolic acid as an anti-filarial agent.

    Directory of Open Access Journals (Sweden)

    Komal Kalani

    Full Text Available As part of our drug discovery program for anti-filarial agents from Indian medicinal plants, leaves of Eucalyptus tereticornis were chemically investigated, which resulted in the isolation and characterization of an anti-filarial agent, ursolic acid (UA as a major constituent. Antifilarial activity of UA against the human lymphatic filarial parasite Brugia malayi using in vitro and in vivo assays, and in silico docking search on glutathione-s-transferase (GST parasitic enzyme were carried out. The UA was lethal to microfilariae (mf; LC100: 50; IC50: 8.84 µM and female adult worms (LC100: 100; IC50: 35.36 µM as observed by motility assay; it exerted 86% inhibition in MTT reduction potential of the adult parasites. The selectivity index (SI of UA for the parasites was found safe. This was supported by the molecular docking studies, which showed adequate docking (LibDock scores for UA (-8.6 with respect to the standard antifilarial drugs, ivermectin (IVM -8.4 and diethylcarbamazine (DEC-C -4.6 on glutathione-s-transferase enzyme. Further, in silico pharmacokinetic and drug-likeness studies showed that UA possesses drug-like properties. Furthermore, UA was evaluated in vivo in B. malayi-M. coucha model (natural infection, which showed 54% macrofilaricidal activity, 56% female worm sterility and almost unchanged microfilaraemia maintained throughout observation period with no adverse effect on the host. Thus, in conclusion in vitro, in silico and in vivo results indicate that UA is a promising, inexpensive, widely available natural lead, which can be designed and developed into a macrofilaricidal drug. To the best of our knowledge this is the first ever report on the anti-filarial potential of UA from E. tereticornis, which is in full agreement with the Thomson Reuter's 'Metadrug' tool screening predictions.

  19. Seasonal prevalence and blood meal analysis of filarial vector Culex quinquefasciatus in coastal areas of Digha, West Bengal, India.

    Science.gov (United States)

    Azmi, Syed Afrin; Das, Surajit; Chatterjee, Soumendranath

    2015-09-01

    Filariasis is one of the major vector-borne diseases causing serious health problem in the tropics and subtropics. The coastal areas of Digha are known to be a filariasis prone region of West Bengal, India. The filarial parasite Wuchereria bancrofti is transmitted by Culex quinquefasciatus, the established filarial vector in West Bengal, India. The present work was aimed to determine the abundance of different mosquito species; and the frequency, distribution and blood meal analysis of Cx. quinquefasciatus in coastal areas of Digha. During the present study, a total of 11,537 mosquitoes [Cx. quinquefasciatus, Armigeres subalbatus, Anopheles barbirostris, An. annularis, An. subpictus, An. sundaicus, Aedes albopictus, and Cx. vishnui (group)] were collected by hand collection method from human habitations and cattlesheds of 10 villages of Digha, West Bengal, India. The seasonal prevalence of Cx. quinquefasciatus was studied. In each season, blood meals of 300 Cx. quinquefasciatus collected from human habitations were analysed during the study period. Cx. quinquefasciatus was found to be the dominant species (88.44% of the total collection) in the study area. It was most frequently found in and around human habitations than cattlesheds. Total man hour density calculation revealed that this species was most prevalent during the rainy season. Two-way ANOVA revealed that the abundance of Cx. quinquefasciatus varied with different seasons. Blood meal analysis showed that the filarial vector preferred human blood than that of other animals. This study suggested Cx. quinquefasciatus as the dominant mosquito species in the study area; and the anthropophilic nature of Cx. quinquefasciatus might be the reason of increase in the intensity of filarial transmission in coastal areas of Digha.

  20. Modulation of CD4+ and CD8+ T-Cell Function by Interleukin 19 and Interleukin 24 During Filarial Infections.

    Science.gov (United States)

    Anuradha, Rajamanickam; Munisankar, Saravanan; Dolla, Chandrakumar; Kumaran, Paul; Nutman, Thomas B; Babu, Subash

    2016-03-01

    Interleukin 19 (IL-19) and interleukin 24 (IL-24) are cytokines that are highly expressed in filarial infections. To study the role of IL-19 and IL-24 in regulating T-cell responses, we examined the frequency of T-helper type 1 (Th1)/Tc1, Th2/Tc2, Th9/Tc9, Th17/Tc17, Th22/Tc22, and Tr1 cells in 26 filariae-infected individuals stimulated with filarial antigen following IL-19 or IL-24 neutralization. IL-19 or IL-24 neutralization resulted in significantly enhanced frequencies of Th1/Tc1 and/or Th17/Tc17 cells and significantly reduced frequencies of Th2/Tc2, Tr1, and/or Th9/Tc9 cells. Thus, we demonstrate that IL-19 and IL-24 are associated with the modulation of T-cell responses in filarial infections. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  1. Predator-prey interactions of nematode-trapping fungi and nematodes: both sides of the coin.

    Science.gov (United States)

    Vidal-Diez de Ulzurrun, Guillermo; Hsueh, Yen-Ping

    2018-05-01

    Nematode-trapping fungi develop complex trapping devices to capture and consume nematodes. The dynamics of these organisms is especially important given the pathogenicity of nematodes and, consequently, the potential application of nematode-trapping fungi as biocontrol agents. Furthermore, both the nematodes and nematode-trapping fungi can be easily grown in laboratories, making them a unique manipulatable predator-prey system to study their coevolution. Several different aspects of these fungi have been studied, such as their genetics and the different factors triggering trap formation. In this review, we use the nematode-trapping fungus Arthrobotrys oligospora (which forms adhesive nets) as a model to describe the trapping process. We divide this process into several stages; namely attraction, recognition, trap formation, adhesion, penetration, and digestion. We summarize the latest findings in the field and current knowledge on the interactions between nematodes and nematode-trapping fungi, representing both sides of the predator-prey interaction.

  2. Nematode Indicators of Organic Enrichment

    NARCIS (Netherlands)

    Ferris, H.; Bongers, A.M.T.

    2006-01-01

    The organisms of the soil food web, dependent on resources from plants or on amendment from other sources, respond characteristically to enrichment of their environment by organic matter. Primary consumers of the incoming substrate, including bacteria, fungi, plant-feeding nematodes, annelids, and

  3. Clerodendron inerme Gaertn. plant as an effective natural product against dengue and filarial vector mosquitoes

    Directory of Open Access Journals (Sweden)

    Prabhakargouda Basanagouda Patil

    2014-02-01

    Full Text Available Objective: To investigate insecticidal properties of organic solvent extracts of Clerodendron inerme (C. inerme leaves against larval stages of Aedes aegypti (Ae. aegypti and Culex quinquefasciatus (Cx. quinquefasciatus mosquito species. Methods: The sundried leaf powder of C. inerme was subjected for extraction using organic solvents viz. methanol, chloroform, petroleum ether and hexane extract, and were tested against third/fourth instar larvae of Ae. aegypti and Cx. quinquefasciatus species in accordance with WHO standard methods. Experiments were conducted in four replicates with control group containing water alone and positive control group containing respective solvent (dimethylsulfoxide/acetone used for dissolving the extracts. Results: Among the four solvent extracts, hexane extract has effective growth disruptive activity against Ae. aegypti, and showed positive tests for presence of four groups of phytochemical constituents viz. tanin, phytosteriod, terpenoid and cardiac glycoside. The hexane extract was tested against field collected filarial vector Cx. quinquefasciatus larvae for growth disruptive activity. Adult emergence inhibition values for 50 percent suppression (EI50 of the tested population for methanol, chloroform, petroleum ether and hexane extracts treated against third instar larvae of Ae. aegypti were found to be 37.45, 14.79, 2.56 and 1.96 mg/L respectively, while hexane extract treated against Cx. quinquefasciatus was found to be equally effective with EI50 value of 3.74 mg/L. Hexane extract treated against fourth instar larvae of Ae. aegypti and Cx. quinquefasciatus showed EI50 values of 8.07 and 19.55 mg/L respectively in comparison with that of standard insect growth regulator methoprene demonstrating EI50 value of 0.05 mg/L. Besides, the hexane extract was also found to possess toxic effect against non-target organism Gambusia affinis (a bio-control agent, however, the lethal concentration (LC50=172.7 mg/L for 24 h

  4. A mechanism for chronic filarial hydrocele with implications for its surgical repair.

    Directory of Open Access Journals (Sweden)

    Joaquim Norões

    Full Text Available BACKGROUND: Chronic hydrocele is the most common manifestation of bancroftian filariasis, an endemic disease in 80 countries. In a prospective study, we evaluated the occurrence of intrascrotal lymphangiectasia, gross appearance/consistency of the testis, and the efficacy of complete excision of hydrocele sac in patients living in a bancroftian filariasis endemic area who underwent hydrocelectomy at the Center for Teaching, Research and Tertiary Referral for Bancroftian Filariasis (NEPAF. METHODOLOGY/PRINCIPAL FINDINGS: A total of 968 patients with uni- or bilateral filarial hydrocele (Group-1 and a Comparison Group (CG of 218 patients from the same area who already had undergone hydrocele-sac-sparing hydrocelectomy elsewhere were enrolled at NEPAF. Twenty-eight patients from the Comparison Group with hydrocele recurrence were re-operated on at NEPAF and constitute Group-2. In Group-1 a total of 1,128 hydrocelectomies were performed (mean patient age of 30.3 yr and mean follow-up of 8.6 yr [range 5.3-12]. The hydrocele recurrence rates in Group-1 and in the Comparison Group (mean age of 31.5 yr were 0.3%, and 19.3%, respectively (p<0,001. There was no hydrocele recurrence in Group-2 (mean patient age of 25.1 yr and mean follow-up of 6 yr [range 5-6.9]. Per surgically leaking or leak-prone dilated lymphatic vessels were seen in the inner or outer surface of the hydrocele sac wall or in surrounding tissue, particularly in the retrotesticular area, in 30.9% and in 46.3% of patients in Group-1 and Group-2, respectively (p = 0.081. The testicles were abnormal in shape, volume, and consistency in 203/1,128 (18% and 10/28 (35.7% of patients from Group-1 and Group-2, respectively (p = 0,025. CONCLUSIONS/SIGNIFICANCE: Lymph fluid from ruptured dilated lymphatic vessels is an important component of chronic filarial hydrocele fluid that threatens the integrity of the testis in an adult population living in bancroftian filariasis endemic areas. To avoid

  5. A mechanism for chronic filarial hydrocele with implications for its surgical repair.

    Science.gov (United States)

    Norões, Joaquim; Dreyer, Gerusa

    2010-06-01

    Chronic hydrocele is the most common manifestation of bancroftian filariasis, an endemic disease in 80 countries. In a prospective study, we evaluated the occurrence of intrascrotal lymphangiectasia, gross appearance/consistency of the testis, and the efficacy of complete excision of hydrocele sac in patients living in a bancroftian filariasis endemic area who underwent hydrocelectomy at the Center for Teaching, Research and Tertiary Referral for Bancroftian Filariasis (NEPAF). A total of 968 patients with uni- or bilateral filarial hydrocele (Group-1) and a Comparison Group (CG) of 218 patients from the same area who already had undergone hydrocele-sac-sparing hydrocelectomy elsewhere were enrolled at NEPAF. Twenty-eight patients from the Comparison Group with hydrocele recurrence were re-operated on at NEPAF and constitute Group-2. In Group-1 a total of 1,128 hydrocelectomies were performed (mean patient age of 30.3 yr and mean follow-up of 8.6 yr [range 5.3-12]). The hydrocele recurrence rates in Group-1 and in the Comparison Group (mean age of 31.5 yr) were 0.3%, and 19.3%, respectively (phydrocele recurrence in Group-2 (mean patient age of 25.1 yr and mean follow-up of 6 yr [range 5-6.9]). Per surgically leaking or leak-prone dilated lymphatic vessels were seen in the inner or outer surface of the hydrocele sac wall or in surrounding tissue, particularly in the retrotesticular area, in 30.9% and in 46.3% of patients in Group-1 and Group-2, respectively (p = 0.081). The testicles were abnormal in shape, volume, and consistency in 203/1,128 (18%) and 10/28 (35.7%) of patients from Group-1 and Group-2, respectively (p = 0,025). Lymph fluid from ruptured dilated lymphatic vessels is an important component of chronic filarial hydrocele fluid that threatens the integrity of the testis in an adult population living in bancroftian filariasis endemic areas. To avoid hydrocele recurrence the authors advise complete excision of hydrocele sac and when identified, leaking

  6. Assessment of macrofilaricidal activity of leaf extracts of Terminalia sp. against bovine filarial parasite Setaria cervi.

    Science.gov (United States)

    Behera, Dipti Ranjan; Bhatnagar, Sunita

    2018-02-05

    Antifilarial potential of three medicinal plants namely, Terminalia bellerica, Terminalia chebula and Terminalia catappa was explored using Setaria cervi, a bovine filarial parasite at concentrations of 2.5, 5 and 10mg/ml. Amongst all the extracts, methanol extract of T. bellerica showed highest macrofilaricidal activity i.e. 84.63±1.11 at 10mg/ml in MTT reduction assay with IC 50 value of 2.7mg/ml. which was better than the standard DEC i.e. 79.22±3.1% at 10mg/ml with IC 50 value 2.84mg/ml. Other plant extracts showed mild in vitro macrofilaricidal activity. T. bellerica methanol extract exhibited significant GST activity of 18.86±0.21 and 12.83±0.03μM/ml/min at 5 and 10mg/ml with percentage inhibition value of 73.96% and 82.29% respectively. DEC showed GST activity value of 40.03±4.14 and 21.48±6.44μM/ml/min with percentage inhibition value of 21.76% and 58.01% at 5 and 10mg/ml respectively. Thus, methanol extract of leaves of T. bellerica exhibited highly significant antifilarial potential and needs detailed analysis. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Detection of human filarial parasite Brugia malayi in dogs by histochemical staining and molecular techniques.

    Science.gov (United States)

    Ambily, V R; Pillai, Usha Narayana; Arun, R; Pramod, S; Jayakumar, K M

    2011-09-27

    Human filariasis caused by Brugia malayi is still a public health problem in many countries of Asia including India, Indonesia, Malaysia and Thailand. The World Health Organization (WHO) has targeted to eliminate filariasis by the year 2020 by Mass annual single dose Diethylcarbamazine Administration (MDA). Results of the MDA programme after the first phase was less satisfactory than expected. Malayan filariasis caused by B. malayi is endemic in the south of Thailand where domestic cat serves as the major reservoir host. There is no report about the occurrence of B. malayi in dogs. The present work was carried out to find out the incidence of microfilariasis in dogs and also to detect the presence of human filarial infection in dogs, if any. One hundred dogs above 6 months of age presented to the veterinary college Hospital, Mannuthy, Kerala, with clinical signs suggestive of microfilariasis - fever, anorexia, conjunctivitis, limb and scrotal oedema - were screened for microfilariae by wet film examination. Positive cases were subjected to Giemsa staining, histochemical staining and molecular techniques. Results of the study showed that 80% of dogs had microfilariasis; out of which 20% had sheathed microfilaria. Giemsa and histochemical staining character, PCR and sequencing confirmed it as B. malayi. High prevalence of B. malayi in dogs in this study emphasized the possible role of dogs in transmission of human filariasis. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Molecular cloning, purification and characterisation of myosin of human lymphatic filarial parasite Brugia malayi.

    Science.gov (United States)

    Verma, S K; Bansal, I; Vedi, S; Saxena, J K; Katoch, V M; Bhattacharya, S M

    2008-02-01

    Global efforts have been made towards development of vaccine for prevention of lymphatic filariasis. However, lack of thorough knowledge about developmental biology and pathogenesis of filarial parasite restricts us from developing an effective vaccine. A limited number of immunodominant antigens of human lymphatic filariid Brugia malayi have been characterised; however, none of these recombinant antigens so far induced significant degree of protective immunity to challenge infection. In the present study, we identified a approximately 2.0 Kb cDNA clone by immunoscreening of cDNA library of adult female Brugia malayi. The nucleotide sequence of the identified clone showed 94.3% homology with C-terminal part of myosin heavy chain gene of Brugia malayi. This cDNA insert was sub-cloned into pET28b vector and expressed in BL21(DE3). The recombinant protein was purified to near homogeneity by immobilised metal affinity chromatography (IMAC) with yield of approximately 25 mg/l. The purified protein was recognised in western blot with anti-His tag antibody as also with the antibodies present in the sera of human W. bancrofti patients of all categories and infected/immunized rodent serum demonstrating its functional role. Recombinant myosin induced marked cellular immune response as observed by lymphoproliferation assay. The present findings demonstrate the usefulness of B. malayi recombinant myosin as vaccine candidate against human lymphatic filariasis.

  9. Impact of climate change on filarial vector, Culex quinquefasciatus and control using bacterial pesticide, spinosad

    Directory of Open Access Journals (Sweden)

    Nareshkumar Arjunan

    2014-02-01

    Full Text Available Objective: To show the effect of temperature on the biology of Culex quinquefasciatus and also to show the effect of the bacterial pesticide, spinosad on developmental stages of the filarial vector. Methods: A laboratory colony of mosquito larvae was used for the larvicidal activity of temperature and spinosad. Twenty-five numbers of first, second, third, fourth instar larvae were introduced into the 500 mL glass beaker containing 250 mL of de-chlorinated water with desired temperatures (16 °C, 20 °C, 24 °C, 28 °C, 32 °C, 36 °C, similarly spinosad, at different concentrations. The development was observed for every 24 h. Results: The results showed that the rise in temperature acts as a growth inhibiting factor for mosquitoes. And no development was found in the temperature below 16 °C and above 36 °C. The hatchability was increased as the temperature was increased up to 32 °C, after which eclosion rates dropped gradually. Conclusions: 32 °C was obtained as the maximum sustainable temperature and after which the developmental rate was gradually reduced. The optimal temperature for development was lower than the temperatures at which development was quickest. The bacterial pesticide spinosad showed that it is an effective mosquito control agent and can be used for further integrated pest management programmes.

  10. Survey of Nematodes on Coffee in Hawaii

    Science.gov (United States)

    Schenck, S.; Schmitt, D. P.

    1992-01-01

    Surveys of coffee fields in Hawaii during 1989-1991 indicated the presence of 10 nematode species in 8 genera. After coffee was planted in fields previously in sugarcane, populations of Criconemella sp. and Pratylenchus zeae gradually decreased, while Rotylenchulus reniformis and, in one field, Meloidogyne incognita, increased in numbers. Coffee is a poor host of R. reniformis, but weeds in coffee plantations may support this nematode. At present, nematodes pose no serious threat to Hawaii's expanding coffee industry. PMID:19283060

  11. Phylogeny of nematodes from birds of prey

    OpenAIRE

    Honisch, Michaela

    2010-01-01

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

  12. Survey of Nematodes on Coffee in Hawaii

    OpenAIRE

    Schenck, S.; Schmitt, D. P.

    1992-01-01

    Surveys of coffee fields in Hawaii during 1989-1991 indicated the presence of 10 nematode species in 8 genera. After coffee was planted in fields previously in sugarcane, populations of Criconemella sp. and Pratylenchus zeae gradually decreased, while Rotylenchulus reniformis and, in one field, Meloidogyne incognita, increased in numbers. Coffee is a poor host of R. reniformis, but weeds in coffee plantations may support this nematode. At present, nematodes pose no serious threat to Hawaii's ...

  13. Seasonal and diurnal biting activities and zoonotic filarial infections of two Simulium species (Diptera: Simuliidae in northern Thailand

    Directory of Open Access Journals (Sweden)

    Ishii Y.

    2008-06-01

    Full Text Available Seasonal and daily biting activity patterns, and natural filarial infections of adult black flies attracted to human bait were investigated at Ban Pang Faen, a rural area in Chiang Mai Province in northern Thailand. Collections were carried out twice a month from 06-00 to 18-00 hours from January 2005 to February 2006. Among ten Simulium species collected, S. nodosum and S. asakoae were predominant occupying 57.3% and 37.2% of the total 16, 553 females, respectively. These two predominant species showed different patterns in seasonal abundance: majority of S. nodosum (86.7% were collected in hot season (from mid February to mid May, while most of S. asakoae (74.5% were collected in rainy season (from mid May to mid October. For the daily biting activity, S. nodosum had two patterns: the main one was unimodal with a peak from 17-00 to 18-00, and the other was bimodal and had the major peak from 16-00 to 18-00 and the minor one from 07-00 to 09-00. The pattern of S. asakoae was mostly unimodal with a peak from 06-00 to 10-00. The filarial larvae found in S. nodosum and S. asakoae were morphologically different from each other. The short and thick infective larvae found in S. asakoae differed from all known filarial larvae; it is suggested that they might be a bird parasite, Splendidofilariinae or Lemdaninae. The infection of the mammophilic S. nodosum with large Onchocerca type infective larvae was confirmed in this area. Natural filarial infections were found in each month (except December in either S. nodosum or S. asakoae or in both. Monthly infection rates with all stages of larvae were 0.6-5.0% for S. nodosum, and 1.0-4.0% for S. asakoae. It is suggested that people in this village are exposed to the risk of infection with zoonotic filariae throughout the year.

  14. Lymphatic filariasis elimination efforts in Rufiji, southeastern Tanzania: decline in circulating filarial antigen prevalence in young school children after twelve rounds of mass drug administration and utilization of long-lasting insecticide-treated nets.

    Science.gov (United States)

    Jones, Clarer; Ngasalla, Billy; Derua, Yahya A; Tarimo, Donath; Malecela, Mwelecele N

    2017-08-01

    Lymphatic filariasis (LF) is a parasitic infection transmitted by mosquito vectors, and in Sub-Saharan Africa it is caused by the nematode Wuchereria bancrofti. The disease has been targeted for global elimination with the annual mass drug administration (MDA) strategy. Vector control is known to play an important complementary role to MDA in reducing the transmission of LF. The effects of an MDA and insecticide-treated net intervention implemented in an endemic area of southeastern Tanzania are reported here. A cross-sectional study assessing W. bancrofti circulating filarial antigen (CFA) was conducted in five primary schools in five different villages. Standard one pupils aged 6-9 years were screened for CFA using immunochromatographic test cards (ICT), with a total of 413 screened in 2012 and 659 in 2015. Just after CFA testing, the children were interviewed on their participation in the MDA campaign. Moreover, 246 heads of households in 2012 and 868 in 2015 were interviewed on their participation in MDA and utilization of long-lasting insecticide-treated nets (LLINs). The prevalence of CFA for the 413 children tested in 2012 was 14.3%, while it was 0.0% for the 659 children tested in 2015. The Tanzanian National Lymphatic Filariasis Elimination Programme reported annual treatment coverage for Rufiji District ranging from 54.3% to 94.0% during the years 2002-2014. The surveyed treatment was 51.6% in 2011 and 57.4% in 2014. With regard to LLINs, possession and utilization increased from 63.4% and 59.2%, respectively, in 2012, to 92.5% and 75.4%, respectively, in 2015. The findings suggest that 12 rounds of MDA complemented with vector control through the use of insecticide-treated nets resulted in a marked reduction in W. bancrofti CFA in young school children. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Condensed tannins act against cattle nematodes

    DEFF Research Database (Denmark)

    Novobilský, Adam; Mueller-Harvey, Irene; Thamsborg, Stig Milan

    2011-01-01

    The use of natural plant anthelmintics was suggested as a possible alternative control of gastrointestinal nematodes (GIN) in ruminants. Direct anthelmintic effects of tannin-containing plants have already been shown in sheep and goat GIN. These anthelmintic properties are mainly associated with ...... extracts. Our results, therefore, indicated that tannin-containing plants could act against cattle nematodes....

  16. Benthic freshwater nematode community dynamics under conditions ...

    African Journals Online (AJOL)

    Studies of the influence of fish aquaculture on benthic freshwater nematode assemblages are scarce, but could provide a way of gauging environmental effects. The abundance and diversity of nematode assemblages in response to Oreochromis niloticus aquaculture were investigated in Kafr El-Sheikh Governorate, Egypt, ...

  17. How do humans affect wildlife nematodes?

    Science.gov (United States)

    Weinstein, Sara B.; Lafferty, Kevin D.

    2015-01-01

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

  18. Genetic analysis of root-knot nematode resistance in potato

    NARCIS (Netherlands)

    Draaistra, J.

    2006-01-01

    The development of potato varieties with resistance towards the potato cyst nematode, allowed a dramatic decrease of the use of nematicides. Subsequently the population of the free living nematodes and the root-knot nematodes ( Meloidogyne spp.) has increased. Among the root-knot nematodes, three

  19. Parasitic Nematode Interactions with Mammals and Plants

    NARCIS (Netherlands)

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

    2003-01-01

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

  20. WormBase: Annotating many nematode genomes.

    Science.gov (United States)

    Howe, Kevin; Davis, Paul; Paulini, Michael; Tuli, Mary Ann; Williams, Gary; Yook, Karen; Durbin, Richard; Kersey, Paul; Sternberg, Paul W

    2012-01-01

    WormBase (www.wormbase.org) has been serving the scientific community for over 11 years as the central repository for genomic and genetic information for the soil nematode Caenorhabditis elegans. The resource has evolved from its beginnings as a database housing the genomic sequence and genetic and physical maps of a single species, and now represents the breadth and diversity of nematode research, currently serving genome sequence and annotation for around 20 nematodes. In this article, we focus on WormBase's role of genome sequence annotation, describing how we annotate and integrate data from a growing collection of nematode species and strains. We also review our approaches to sequence curation, and discuss the impact on annotation quality of large functional genomics projects such as modENCODE.

  1. Genome Evolution of Plant-Parasitic Nematodes.

    Science.gov (United States)

    Kikuchi, Taisei; Eves-van den Akker, Sebastian; Jones, John T

    2017-08-04

    Plant parasitism has evolved independently on at least four separate occasions in the phylum Nematoda. The application of next-generation sequencing (NGS) to plant-parasitic nematodes has allowed a wide range of genome- or transcriptome-level comparisons, and these have identified genome adaptations that enable parasitism of plants. Current genome data suggest that horizontal gene transfer, gene family expansions, evolution of new genes that mediate interactions with the host, and parasitism-specific gene regulation are important adaptations that allow nematodes to parasitize plants. Sequencing of a larger number of nematode genomes, including plant parasites that show different modes of parasitism or that have evolved in currently unsampled clades, and using free-living taxa as comparators would allow more detailed analysis and a better understanding of the organization of key genes within the genomes. This would facilitate a more complete understanding of the way in which parasitism has shaped the genomes of plant-parasitic nematodes.

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

    African Journals Online (AJOL)

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

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

    Science.gov (United States)

    Silvestre, A; Cabaret, J

    2004-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Silvestre A.

    2004-06-01

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

  5. Tropical nematode diversity: vertical stratification of nematode communities in a Costa Rican humid lowland rainforest.

    Science.gov (United States)

    Powers, T O; Neher, D A; Mullin, P; Esquivel, A; Giblin-Davis, R M; Kanzaki, N; Stock, S P; Mora, M M; Uribe-Lorio, L

    2009-03-01

    Comparisons of nematode communities among ecosystems have indicated that, unlike many organisms, nematode communities have less diversity in the tropics than in temperate ecosystems. There are, however, few studies of tropical nematode diversity on which to base conclusions of global patterns of diversity. This study reports an attempt to estimate nematode diversity in the lowland tropical rainforest of La Selva Biological Research Station in Costa Rica. We suggest one reason that previous estimates of tropical nematode diversity were low is because habitats above the mineral soil are seldom sampled. As much as 62% of the overall genetic diversity, measured by an 18S ribosomal barcode, existed in litter and understorey habitats and not in soil. A maximum-likelihood tree of barcodes from 360 individual nematodes indicated most major terrestrial nematode lineages were represented in the samples. Estimated 'species' richness ranged from 464 to 502 within the four 40 x 40 m plots. Directed sampling of insects and their associated nematodes produced a second set of barcodes that were not recovered by habitat sampling, yet may constitute a major class of tropical nematode diversity. While the generation of novel nematode barcodes proved relatively easy, their identity remains obscure due to deficiencies in existing taxonomic databases. Specimens of Criconematina, a monophyletic group of soil-dwelling plant-parasitic nematodes were examined in detail to assess the steps necessary for associating barcodes with nominal species. Our results highlight the difficulties associated with studying poorly understood organisms in an understudied ecosystem using a destructive (i.e. barcode) sampling method.

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

    Directory of Open Access Journals (Sweden)

    Karabörklü Salih

    2015-01-01

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

  7. Comparative studies on the biology and filarial susceptibility of selected blood-feeding and autogenous Aedes togoi sub-colonies

    Directory of Open Access Journals (Sweden)

    Anuluck Junkum

    2003-06-01

    Full Text Available Blood-feeding and autogenous sub-colonies were selected from a laboratory, stock colony of Aedes togoi, which was originally collected from Koh Nom Sao, Chanthaburi province, Southeast Thailand. Comparative biology and filarial susceptibility between the two sub-colonies (blood-feeding: F11, F13; autogeny: F38, F40 were investigated to evaluate their viability and vectorial capacity. The results of comparison on biology revealed intraspecific differences, i.e., the average egg deposition/gravid female (F11/F38; F13/F40, embryonation rate (F13/F40, hatchability rate (F11/F38; F13/F40, egg width (F11/F38, wing length of females (F13/F40, and wing length and width of males (F11/F38 in the blood-feeding sub-colony were significantly greater than that in the autogenous sub-colony; and egg length (F11/F38 and width (F13/F40, and mean longevity of adult females (F11/F38 and males (F13/F40 in the blood-feeding sub-colony were significantly less than that in the autogenous sub-colony. The results of comparison on filarial susceptibility demonstrated that both sub-colonies yielded similar susceptibilities to Brugia malayi [blood-feeding/autogeny = 56.7% (F11/53.3%(F38, 60%(F13/83.3%(F40] and Dirofilaria immitis [blood-feeding/autogeny = 85.7%(F11/75%(F38, 45%(F13/29.4%(F40], suggesting autogenous Ae. togoi sub-colony was an efficient laboratory vector in study of filariasis.

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

    NARCIS (Netherlands)

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

    2006-01-01

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

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

    NARCIS (Netherlands)

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

    2006-01-01

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

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

    African Journals Online (AJOL)

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

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

    Indian Academy of Sciences (India)

    YONGCHUN LI

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

  12. Nematode-plant interactions in grasslands under restoration management

    NARCIS (Netherlands)

    Verschoor, B.C.

    2001-01-01

    Keywords : competition, fertilisation, food quality, grassland, herbivory, nitrogen, nutrients, plant-feeding nematodes, productivity, restoration management, succession, synergism, vegetation

    Plant-feeding nematodes may have a considerable

  13. Extended phenotype: nematodes turn ants into bird-dispersed fruits

    DEFF Research Database (Denmark)

    Hughes, D P; Kronauer, D J C; Boomsma, J J

    2008-01-01

    A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs.......A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs....

  14. Microbial ecology and nematode control in natural ecosystems

    NARCIS (Netherlands)

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

    2011-01-01

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

  15. Selectable genetic markers for nematode transgenesis.

    Science.gov (United States)

    Giordano-Santini, Rosina; Dupuy, Denis

    2011-06-01

    The nematode Caenorhabditis elegans has been used to study genetics and development since the mid-1970s. Over the years, the arsenal of techniques employed in this field has grown steadily in parallel with the number of researchers using this model. Since the introduction of C. elegans transgenesis, nearly 20 years ago, this system has been extensively used in areas such as rescue experiments, gene expression studies, and protein localization. The completion of the C. elegans genome sequence paved the way for genome-wide studies requiring higher throughput and improved scalability than provided by traditional genetic markers. The development of antibiotic selection systems for nematode transgenesis addresses these requirements and opens the possibility to apply transgenesis to investigate biological functions in other nematode species for which no genetic markers had been developed to date.

  16. Remote Sensing of Parasitic Nematodes in Plants

    Science.gov (United States)

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2018-02-05

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

  18. Nematode populations as influenced by Leucaena leucocephala ...

    African Journals Online (AJOL)

    study to determine the effect of Flemingia congesta and Leucaena leucocephala hedgerows, as sources of mulch, on the population of nematode species in an alley cropping system was conducted at the Crops Research Institute, Kumasi, Ghana from May 1991 to February 1994. Treatments comprised Leucaena ...

  19. Evaluation of nematode suppression and yield improvement ...

    African Journals Online (AJOL)

    SARAH

    2017-11-30

    Nov 30, 2017 ... Objective: To investigate nematode suppression and yield improvement potential of two organic materials; poultry manure ... region of Ghana. The organic materials were applied on two sweet potato varieties; Apomuden and Santom ..... but a trend similar to what happened in 2014 occurred at. Atebubu.

  20. Cell cycle activation by plant parasitic nematodes

    NARCIS (Netherlands)

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

    2000-01-01

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

  1. TABLE PREVALENCE OF GIT NEMATODES IN CATTLE

    African Journals Online (AJOL)

    User

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

  2. Prevalence of parasitic gastrointestinal nematodes of small ...

    African Journals Online (AJOL)

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

  3. Nematode survival in relation to soil moisture

    NARCIS (Netherlands)

    Simons, W.R.

    1973-01-01

    Established nematode populations are very persistent in the soil. It is known that they need sufficient soil moisture for movement, feeding and reproduction (fig. 5), and that there are adverse soil moisture conditions which they cannot survive. The influence of soil moisture on survival

  4. Epidemiology and Control of Gastrointestinal Nematodes Infections ...

    African Journals Online (AJOL)

    A study on the epidemiology and control of gastrointestinal nematode infections in lambs in a semi-arid area of Kajiado District of Kenya was carried out between January 2001 and December 2001. Forty Dorper lambs were randomly recruited at the age of 6 weeks and their faecal samples examined for strongyle-type ...

  5. Isolation of entomopathogenic nematodes and control of ...

    African Journals Online (AJOL)

    Jaime Ruiz

    This study aimed to isolate native entomopathogenic nematodes (EPN) in the Central Valleys of Oaxaca and to determine their potential for control of white grub (Phyllophaga vetula Horn). Fifty-five (55) soil samples were collected in 13 communities in the period August to October 2008 and 29.1% of these were found ...

  6. Evolution of embryonic development in nematodes

    Directory of Open Access Journals (Sweden)

    Schulze Jens

    2011-09-01

    Full Text Available Abstract Background Nematodes can be subdivided into basal Enoplea (clades 1 and 2 and more derived Chromadorea (clades 3 to 12. Embryogenesis of Caenorhabditis elegans (clade 9 has been analyzed in most detail. Their establishment of polarity and asymmetric cleavage requires the differential localization of PAR proteins. Earlier studies on selected other nematodes revealed that embryonic development of nematodes is more diverse than the essentially invariant development of C. elegans and the classic study object Ascaris had suggested. To obtain a more detailed picture of variations and evolutionary trends we compared embryonic cell lineages and pattern formation in embryos of all 12 nematode clades. Methods The study was conducted using 4-D microscopy and 3-D modeling of developing embryos. Results We found dramatic differences compared to C. elegans in Enoplea but also considerable variations among Chromadorea. We discovered 'Polarity Organizing Centers' (POCs that orient cleavage spindles along the anterior-posterior axis in distinct cells over consecutive cell generations. The resulting lineally arranged blastomeres represent a starting point for the establishment of bilateral symmetry within individual lineages. We can discern six different early cleavage types and suggest that these variations are due to modifications in the activity of the POCs in conjunction with changes in the distribution of PAR proteins. In addition, our studies indicate that lineage complexity advanced considerably during evolution, that is we observe trends towards an increase of somatic founder cells, from monoclonal to polyclonal lineages and from a variable (position-dependent to an invariable (lineage-dependent way of cell fate specification. In contrast to the early phase of embryogenesis, the second half ('morphogenesis' appears similar in all studied nematodes. Comparison of early cleavage between the basal nematode Tobrilus stefanskii and the tardigrade

  7. Health-seeking behaviors and self-care practices of people with filarial lymphoedema in Nepal: a qualitative study.

    Science.gov (United States)

    Adhikari, Ram Kumar; Sherchand, Jeevan Bahadur; Mishra, Shiva Raj; Ranabhat, Kamal; Pokharel, Amrit; Devkota, Pramila; Mishra, Durga; Ghimire, Yadu Chandra; Gelal, Khageshwor; Paudel, Rajan; Wagle, Rajendra Raj

    2015-01-01

    Background. Lymphatic filariasis is endemic in Nepal. This study aimed to investigate health-seeking behaviors and self-care practices of people with filarial Lymphoedema in Nepal. Methods. A cross-sectional study was conducted using qualitative methods in three endemic districts. Twenty-three patients with current Lymphoedema were recruited in the study. Results. Hydrocele was found to be a well-known condition and a major health problem in the studied communities. People with Lymphoedema primarily sought health care from traditional healers, whereas sometimes home-based care was their first treatment. Later Ayurvedic and allopathic hospital-based care were sought. Respondents reported various psychological problems such as difficulty in engaging in sexual intercourse, anxiety, worry and stress, depression, low self-esteem, feeling weak, fear of being abandoned, and fear of transmitting disease to the children. Standard foot care practices except washing were largely absent. Conclusions. Lymphoedema in the limbs and hydrocele were found to be major health problems. The traditional health care providers were the first contact of care for the majority of respondents. Only a few patients had been practicing standard foot care practices.

  8. Health-Seeking Behaviors and Self-Care Practices of People with Filarial Lymphoedema in Nepal: A Qualitative Study

    Directory of Open Access Journals (Sweden)

    Ram Kumar Adhikari

    2015-01-01

    Full Text Available Background. Lymphatic filariasis is endemic in Nepal. This study aimed to investigate health-seeking behaviors and self-care practices of people with filarial Lymphoedema in Nepal. Methods. A cross-sectional study was conducted using qualitative methods in three endemic districts. Twenty-three patients with current Lymphoedema were recruited in the study. Results. Hydrocele was found to be a well-known condition and a major health problem in the studied communities. People with Lymphoedema primarily sought health care from traditional healers, whereas sometimes home-based care was their first treatment. Later Ayurvedic and allopathic hospital-based care were sought. Respondents reported various psychological problems such as difficulty in engaging in sexual intercourse, anxiety, worry and stress, depression, low self-esteem, feeling weak, fear of being abandoned, and fear of transmitting disease to the children. Standard foot care practices except washing were largely absent. Conclusions. Lymphoedema in the limbs and hydrocele were found to be major health problems. The traditional health care providers were the first contact of care for the majority of respondents. Only a few patients had been practicing standard foot care practices.

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

    Science.gov (United States)

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

    2013-12-01

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

  10. Helminths of Wild Predatory Mammals of Ukraine. Nematodes

    Directory of Open Access Journals (Sweden)

    Varodi E. I.

    2017-06-01

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

  11. Sibling species of the Anopheles funestus group, and their infection with malaria and lymphatic filarial parasites, in archived and newly collected specimens from northeastern Tanzania

    DEFF Research Database (Denmark)

    Derua, Yahya A; Alifrangis, Michael; Magesa, Stephen M

    2015-01-01

    vectors of both malaria and lymphatic filariasis. METHODS: Archived (from 2005-2012) and newly collected (from 2014) specimens of the An. funestus group collected indoors using CDC light traps in villages in northeastern Tanzania were analysed. They were identified to sibling species by PCR based......-parasite dynamics in the area, and to allow for appropriate adjustment of control activities, the present study examined the composition, and malaria and lymphatic filarial infection, of sibling species of the Anopheles funestus group. Similar to the An. gambiae complex, the An. funestus group contains important...

  12. Development of lymphatic filarial parasite Wuchereria bancrofti (Spirurida: Onchocercidae) in mosquito species (Diptera: Culicidae) fed artificially on microfilaremic blood.

    Science.gov (United States)

    Paily, K P; Hoti, S L; Balaraman, K

    2006-11-01

    The efficiency of laboratory colonies of mosquitoes such as Anopheles stephensi Liston, Aedes aegypti (L.) Liverpool strain, Ae. aegypti wild type, Aedes albopictus (Skuse), Culex tritaeniorhynchus Giles, Culex sitiens Wiedemann, and Armigeres subalbatus Coquillett in supporting the development of Wuchereria bancrofti (Cobbold) (Spirurida: Onchocercidae) microfilariae to infective larvae was investigated. The mosquitoes were fed on heparinized microfilaremic human blood by using a membrane-feeding unit with Parafilm as membrane. The rate of infection, parasite development, and parasite burden were compared with that in the known vector mosquito Culex quinquefasciatus Say. Cx. quinquefasciatus showed the highest percentage of infection, followed by Ae. aegypti Liverpool strain and An. stephensi. The rate of development of the parasite was more or less similar in all the three species, and infective larvae were found on day 13. When the larvae were harvested on day 17, Cx. quinquefasciatus yielded the highest numbers, followed by Ae. aegypti Liverpool strain and An. stephensi. The percentage of infection was low, and the development was slow in Cx. tritaeniorhynchus compared with the other susceptible species. The parasite developed to second-stage larvae only by day 22 and to infective larvae by day 28. When 2-wk-old Cx. tritaeniorhynchus were fed on microfilaremic blood, they could develop the parasite to infective larvae by day 13 postfeeding. All other species of mosquitoes tested were found to be refractory to parasite development. It is shown that Cx. quinquefasciatus is the most suitable mosquito host for the production of infective larvae. However, Ae. aegypti Liverpool strain, which is commonly used for Brugia malayi filarial parasite, also can be used for generation of W. bancrofti infective larvae to circumvent the problem of maintaining two mosquito species.

  13. A model for nematode locomotion in soil

    Science.gov (United States)

    Hunt, H. William; Wall, Diana H.; DeCrappeo, Nicole; Brenner, John S.

    2001-01-01

    Locomotion of nematodes in soil is important for both practical and theoretical reasons. We constructed a model for rate of locomotion. The first model component is a simple simulation of nematode movement among finite cells by both random and directed behaviours. Optimisation procedures were used to fit the simulation output to data from published experiments on movement along columns of soil or washed sand, and thus to estimate the values of the model's movement coefficients. The coefficients then provided an objective means to compare rates of locomotion among studies done under different experimental conditions. The second component of the model is an equation to predict the movement coefficients as a function of controlling factors that have been addressed experimentally: soil texture, bulk density, water potential, temperature, trophic group of nematode, presence of an attractant or physical gradient and the duration of the experiment. Parameters of the equation were estimated by optimisation to achieve a good fit to the estimated movement coefficients. Bulk density, which has been reported in a minority of published studies, is predicted to have an important effect on rate of locomotion, at least in fine-textured soils. Soil sieving, which appears to be a universal practice in laboratory studies of nematode movement, is predicted to negatively affect locomotion. Slower movement in finer textured soils would be expected to increase isolation among local populations, and thus to promote species richness. Future additions to the model that might improve its utility include representing heterogeneity within populations in rate of movement, development of gradients of chemical attractants, trade-offs between random and directed components of movement, species differences in optimal temperature and water potential, and interactions among factors controlling locomotion.

  14. Association of nematodes and dogwood cankers.

    Science.gov (United States)

    Self, L H; Bernard, E C

    1994-03-01

    Dogwood canker is a serious production problem of unknown etiology. From May 1985 through April 1989, cankers from 290 flowering dogwood trees in 15 separate nurseries were sampled for nematodes. Seventy-three percent (213) of the cankers contained nematodes. Panagrolaimus rigidus (Schneider) Thorne (115/290) and Aphelenchoides spp. (91/290) were the most frequently collected taxa. Panagrolaimus rigidus was reared on 2% water agar with unidentified bacteria as the food source. Aphelenchoides spp. were reared in antibiotic-amended agar culture with the fungus Glomerella cingulata (Stoneman) Spauld. &Schrenk as a food source. Repeated attempts to culture Aphelenchoides spp. on dogwood callus tissue were unsuccessful. Artificially created stem wounds inoculated with combinations of Aphelenchoides spp. and P. rigidus callused completely in 60 days with no indication of canker development. Very low numbers of nematodes were recovered from inoculated trees, but P. rigidus and one Aphelenchoides sp. were efficient dispersers and occurred in treatments other than those in which they were inoculated.

  15. Assaying environmental nickel toxicity using model nematodes

    Science.gov (United States)

    Rudel, David; Douglas, Chandler; Huffnagle, Ian; Besser, John M.; Ingersoll, Christopher G.

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegansand P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  16. Assaying environmental nickel toxicity using model nematodes.

    Directory of Open Access Journals (Sweden)

    David Rudel

    Full Text Available Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water, we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  17. Assaying environmental nickel toxicity using model nematodes.

    Science.gov (United States)

    Rudel, David; Douglas, Chandler D; Huffnagle, Ian M; Besser, John M; Ingersoll, Christopher G

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  18. Extracting DNA of nematodes communities from Argentine Pampas agricultural soils

    Directory of Open Access Journals (Sweden)

    Eduardo A. Mondino

    2015-06-01

    Full Text Available We examined four strategies (Tris/EDTA, sodium dodecyl sulfate, Chelex 100 resin and cetyltrimethylammonium bromide -CTAB- for extracting nucleic acid (DNA from communities of nematodes. Nematodes were isolated from an agricultural area under different management of long-term crop rotation experiment from Argentina during three seasons. After DNA extraction, Polymerase Chain Reaction-amplifications were performed and considered as indicators of successful DNA extraction. The CTAB combined with proteinase K and phenol-chloroform-isoamyl alcohol was the unique successful method because positive amplifications were obtained by using both eukaryotic and nematode specific primers. This work could contribute to biodiversity studies of nematodes on agroecosystems.

  19. Black flies (Diptera : Simuliidae attracted to humans and water buffalos and natural infections with filarial larvae, probably Onchocerca sp., in northern Thailand

    Directory of Open Access Journals (Sweden)

    Takaoka H.

    2003-03-01

    Full Text Available Several Simulium species were investigated as to their biting habits and natural infections with filarial larvae at Ban Pan Fan, Chiang Mai Province, in northern Thailand. Female adults flies landing on or flighting around a human and a water buffalo were collected during the daytime from 06.00 to 19.00 hours on 22 June 2001. As a result, 217 S. nodosum, 86 S. asakoae and two S. nigrogilvum were obtained from a human attractant, and 416 S. nodosum, 25 S. nakhonense, 16 S. asakoae, four 5. fenestratum and two S. nigrogilvum, from a water buffalo. The blood-feeding was confirmed only for S. nodosum and S. nigrogilvum on humans, and for S. nodosum and S. nakhonense on water buffalos. Dissections of these simuliids showed that S. nodosum was naturally infected with developing filarial larvae. Two types of microfilariae were distinguished but only one type of infective larvae. These larvae resembled Onchocerca suzukii, a parasite from a wild Japanese bovid, suggesting that an unknown Onchocerca species from ruminants was transmitted in Thailand. Infection rates with all stages of larvae and third-stage larvae were 2.3 % (14/608 and 1 .0 % (6/608, respectively. This is the first report of natural infections of black flies with Onchocerca larvae in Southeast Asia, and the involved black fly species is shown to be not only anthropophilic but also zoophilic in this region.

  20. Filarial lymphedema is characterized by antigen-specific Th1 and th17 proinflammatory responses and a lack of regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Subash Babu

    Full Text Available Lymphatic filariasis can be associated with development of serious pathology in the form of lymphedema, hydrocele, and elephantiasis in a subset of infected patients.To elucidate the role of CD4(+ T cell subsets in the development of lymphatic pathology, we examined specific sets of cytokines in individuals with filarial lymphedema in response to parasite antigen (BmA and compared them with responses from asymptomatic infected individuals. We also examined expression patterns of Toll-like receptors (TLR1-10 and Nod-like receptors (Nod1, Nod2, and NALP3 in response to BmA. BmA induced significantly higher production of Th1-type cytokines-IFN-gamma and TNF-alpha-in patients with lymphedema compared with asymptomatic individuals. Notably, expression of the Th17 family of cytokines-IL-17A, IL-17F, IL-21, and IL-23-was also significantly upregulated by BmA stimulation in lymphedema patients. In contrast, expression of Foxp3, GITR, TGFbeta, and CTLA-4, known to be expressed by regulatory T cells, was significantly impaired in patients with lymphedema. BmA also induced significantly higher expression of TLR2, 4, 7, and 9 as well Nod1 and 2 mRNA in patients with lymphedema compared with asymptomatic controls.Our findings implicate increased Th1/Th17 responses and decreased regulatory T cells as well as regulation of Toll- and Nod-like receptors in pathogenesis of filarial lymphedema.

  1. Transgenesis in parasitic nematodes: building a better array

    OpenAIRE

    Lok, James B.

    2009-01-01

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

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

    NARCIS (Netherlands)

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

    2000-01-01

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

  3. Cyst nematode-induced changes in plant development

    NARCIS (Netherlands)

    Goverse, A.

    1999-01-01

    This thesis describes a first attempt to investigate the biological activity of cyst nematode secretions on plant cell proliferation and the molecular mechanisms underlying feeding cell development in plant roots upon cyst nematode infection.

    To investigate the role of

  4. The cyst nematodes Heterodera and Globodera species in Egypt

    Science.gov (United States)

    Information concerning the occurrence and distribution of the cyst nematodes (Heterodera spp. and Globodera spp.) in Egypt is important to assess their potential to cause economic damage to many crop plants. A nematode survey was conducted in Alexandria, El Behera and Sohag governorates during 2012-...

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

    African Journals Online (AJOL)

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

  6. Free-living Marine Nematodes. Part 1 British Enoplids

    African Journals Online (AJOL)

    This is the first of three volumes dealing with the most abundant group of animals on the sea-bed and sea-shore, the free-living marine nematodes, and is devoted to those marine nematodes belonging to the subclass Enoplia. Separate volumes will deal with the orders Chromadorida and. Monhysterida. To most marine ...

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

    African Journals Online (AJOL)

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

  8. Soybean lines evaluated for resistance to reniform nematode

    Science.gov (United States)

    Seventy-four wild and domestic soybean (Glycine max and G. soja) lines were evaluated for resistance to reniform nematode (Rotylenchulus reniformis) in growth chamber tests with a day length of 16 hours and temperature held constant at 28 C. Several entries for which reactions to reniform nematode w...

  9. Screening of in vitro derived mutants of banana against nematodes ...

    African Journals Online (AJOL)

    The rest of the mutants namely Ro Im V4 6-1-2 and Si Im V4 6-2-5 were found to be susceptible to nematodes. The resistant and moderately resistant mutants of banana could be further used in breeding programmes as well as being recognized as potential cultivars of commerce. Key words: Banana, nematode, resistance, ...

  10. Molecular and genetic analyses of potato cyst nematode resistance loci

    NARCIS (Netherlands)

    Bakker, E.H.

    2003-01-01

    This thesis describes the genomic localisation and organisation of loci that harbour resistance to the potato cyst nematode species Globodera pallida and G. rostochiensis . Resistance to the potato cyst nematodes G. pallida and G. rostochiensis is an important aspect in potato breeding. To gain

  11. Integrated management of root-knot nematode (Meloidogyne ...

    African Journals Online (AJOL)

    Integrated management of root-knot nematode (Meloidogyne incognita) for tomato production and productivity. Bayuh Belay1* ... less gall formation, number of eggs per egg mass and final nematode population over the untreated control in the pot house experiment. ...... to Control Plant Pests. University of Idaho. Moscow ...

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

    African Journals Online (AJOL)

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

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

    Science.gov (United States)

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

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

    African Journals Online (AJOL)

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

  15. Nematode community structure as a bioindicator in environmental monitoring

    NARCIS (Netherlands)

    Bongers, T.; Ferris, H.

    1999-01-01

    Four of every five multicellular animals on the planet are nematodes. They occupy any niche that provides an available source of organic carbon in marine, freshwater and terrestrial environments. Nematodes vary in sensitivity to pollutants and environmental disturbance. Recent development of indices

  16. Epidemiological study on abomasal nematodes in slaughtered small ...

    African Journals Online (AJOL)

    Gastrointestinal nematodes are one of the major causes of productivity losses in small ruminants in sub-Saharan Africa. A study was carried out to evaluate the prevalence, worm burden of abomasal nematodes and associated faecal egg counts (FEC) of small ruminants slaughtered from November, 2011 to October, 2012.

  17. Freshwater nematodes from South Africa. 4. The genus Monhystera ...

    African Journals Online (AJOL)

    Freshwater nematodes from South Africa. 4. The genus Monhystera Bastian, 1865. A.P. Joubert and J. Heyns. Department of Zoology. Rand Afrikaans University. During a survey of freshwater nematodes in South Africa, five species of Monhystera Bastian, 1865, were encountered. The five species, three of which are new to ...

  18. Nematode effector proteins: an emerging paradigm of parasitism

    Science.gov (United States)

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

  19. Prevalence of common gastro-intestinal nematode infections in ...

    African Journals Online (AJOL)

    ACSS

    (Hansen and Perry, 1994). Furthermore, nematode egg counting per gramme of faeces (epg) was done on the same samples using the modified McMaster technique, as described by Hansen and. Perry (1994). Identification of third stage nematode larvae. About three grammes of faeces were taken from each sample.

  20. Occurrence and prevalence of nematodes in yam fields from four ...

    African Journals Online (AJOL)

    Nematodes is one of the major biotic constraints affecting profitable yam production throughout Nigeria. They affect yams both in the field and in storage thus threatening food security and economic deprivation to growers and their households. The research work identified the types, frequency and population of nematodes ...

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

    African Journals Online (AJOL)

    Administrator

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

  2. Native nematodes as new bio-insecticides for cranberries

    Science.gov (United States)

    In the summer of 2015, an effort was made in central Wisconsin to find an entomopathogenic nematode capable controlling Wisconsin’s cranberry pests. Using a standard baiting method, a nematode of the Oscheius genus was collected from the mossy, sandy, peat-filled soils of a wild cranberry marsh. Thi...

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

    NARCIS (Netherlands)

    Thoden, T.C.; Boppre, M.

    2010-01-01

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

  4. Control of the peachtree borer using beneficial nematodes

    Science.gov (United States)

    The peachtree borer, Synanthedon exitiosa, is a major pest of peaches and other stone fruits. Our research indicates that entomopathogenic nematodes, also known as beneficial nematodes, can be used effectively to control the insect. We conducted replicated experiments in randomized block designs ov...

  5. Transgenesis in the parasitic nematode Strongyloides ratti.

    Science.gov (United States)

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

    2011-10-01

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

  6. Arrested larval development in cattle nematodes.

    Science.gov (United States)

    Armour, J; Duncan, M

    1987-06-01

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

  7. Some nematodes of freshwater fishes in Venezuela.

    Science.gov (United States)

    Moravec, F; Prouza, A; Royero, R

    1997-01-01

    The present paper comprises a systematic survey of nematodes found in 88 specimens of 24 species of freshwater fishes in Venezuela in 1992 and 1994. The following 13 species of nematodes were recorded: Adults; Guyanema longispiculum Moravec, Prouza et Royero, 1996, Guyanema sp., Procamallanus (Spirocamallanus) inopinatus Travassos, Artigas et Pereira, 1928, P. (S.) krameri (Petter, 1974) comb. n., P.(S.) pintoi (Kohn et Fernandes, 1988) comb, n., Procamallanus (Spirocamallanus) sp., Raphidascaris (Sprentascaris) mahnerti (Petter et Cassone, 1984). Larvae: Anisakidae gen. sp., Brevimulticaecum sp., Contracaecum sp. Type 1, Contracaecum sp. Type 2, Contracaecum sp. Type 3, Eustrongylides sp. All these parasites are reported from Venezuela for the first time and all findings represent new host records. Brevimulticaecum larvae are reported from fishes for the first time. Almost all parasites are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. A new name, Terranova diazungriai nom.nov. is proposed for T. caballeroi Díaz-Ungría, 1968 (a junior homonym of T. caballeroi Barus et Coy Otero, 1966).

  8. Experimental Evolution withCaenorhabditisNematodes.

    Science.gov (United States)

    Teotónio, Henrique; Estes, Suzanne; Phillips, Patrick C; Baer, Charles F

    2017-06-01

    The hermaphroditic nematode Caenorhabditis elegans has been one of the primary model systems in biology since the 1970s, but only within the last two decades has this nematode also become a useful model for experimental evolution. Here, we outline the goals and major foci of experimental evolution with C. elegans and related species, such as C . briggsae and C. remanei , by discussing the principles of experimental design, and highlighting the strengths and limitations of Caenorhabditis as model systems. We then review three exemplars of Caenorhabditis experimental evolution studies, underlining representative evolution experiments that have addressed the: (1) maintenance of genetic variation; (2) role of natural selection during transitions from outcrossing to selfing, as well as the maintenance of mixed breeding modes during evolution; and (3) evolution of phenotypic plasticity and its role in adaptation to variable environments, including host-pathogen coevolution. We conclude by suggesting some future directions for which experimental evolution with Caenorhabditis would be particularly informative. Copyright © 2017 Teotónio et al.

  9. Vertebrate herbivores influence soil nematodes by modifying plant communities.

    Science.gov (United States)

    Veen, G F; Olff, Han; Duyts, Henk; van der Putten, Wim H

    2010-03-01

    Abiotic soil properties, plant community composition, and herbivory all have been reported as important factors influencing the composition of soil communities. However, most studies thus far have considered these factors in isolation, whereas they strongly interact in the field. Here, we study how grazing by vertebrate herbivores influences the soil nematode community composition of a floodplain grassland while we account for effects of grazing on plant community composition and abiotic soil properties. Nematodes are the most ubiquitous invertebrates in the soil. They include a variety of feeding types, ranging from microbial feeders to herbivores and carnivores, and they perform key functions in soil food webs. Our hypothesis was that grazing affects nematode community structure and composition through altering plant community structure and composition. Alternatively, we tested whether the effects of grazing may, directly or indirectly, run via changes in soil abiotic properties. We used a long-term field experiment containing plots with and without vertebrate grazers (cattle and rabbits). We compared plant and nematode community structure and composition, as well as a number of key soil abiotic properties, and we applied structural equation modeling to investigate four possible pathways by which grazing may change nematode community composition. Aboveground grazing increased plant species richness and reduced both plant and nematode community heterogeneity. There was a positive relationship between plant and nematode diversity indices. Grazing decreased the number of bacterial-feeding nematodes, indicating that in these grasslands, top-down control of plant production by grazing leads to bottom-up control in the basal part of the bacterial channel of the soil food web. According to the structural equation model, grazing had a strong effect on soil abiotic properties and plant community composition, whereas plant community composition was the main determinant of

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

    NARCIS (Netherlands)

    Roze, E.H.A.

    2008-01-01

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

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

    OpenAIRE

    Andersson, Karl-Magnus

    2013-01-01

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

  12. Cereal Cyst Nematode (Heterodera avenae) on Oats. II. Early Root Development and Nematode Tolerance

    OpenAIRE

    Volkmar, K. M.

    1989-01-01

    The effect of Heterodera avenae infestation on early seminal and lateral root growth was examined in four oat genotypes differing in tolerance to H. avenae. Recently emerged seminal roots were inoculated with a range of H. avenae larval densities, then transferred a hydroponic system to remove the effect of later nematode penetration on root development. Intolerance to H. avenae was assessed in terms of impairment of seminal root extension resulting in fewer primary lateral roots emerging fro...

  13. Larvicidal activity of Wrightia tinctoria R. BR. (Apocynaceae fruit and leaf extracts against the filarial vector Culex quinquefasciatus Say (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Murugesan Sakthivadivel

    2014-02-01

    Full Text Available Objective: To determine the larvicidal activity of crude aqueous and petroleum ether extracts of Wrightia tinctoria fruits and leaves against the filarial vector, Culex quinquefasciatus. Methods: The larvicidal activity was evaluated at concentrations of 0.06%, 0.12%, 0.25%, 0.50% and 1.00%. Larval mortality was observed for 24 and 48 h. Results: Among the plant parts tested, aqueous fruit extract exhibited highest larvicidal activity followed by aqueous leaf extract with LC50 values of 0.17% and 0.09%; 0.21% and 0.11% after 24 and 48 h respectively. Conclusions: Further investigations are needed to elucidate this activity against a wide range of all stages of mosquito species and also the active ingredient(s of the extract responsible for larvicidal activity should be identified.

  14. Plant nematodes in South Africa. 11. Checklist of plant nematodes of the protected areas of KwaZulu-Natal

    Directory of Open Access Journals (Sweden)

    Mariette Marais

    2013-03-01

    Full Text Available Nematodes are some of the most abundant soil organisms and are an essential part of soil ecology. These organisms are used as indicator organisms and can be linked to soil health. Biological collections contain vast amounts of data, with the National Collection of Nematodes housed at the Plant Protection Research Institute, Agricultural Research Council being no different. During the digitising of the collection a number of unpublished records of plant nematodes reported from protected areas in KwaZulu-Natal were found in the South African Plant-Parasitic Nematode Survey database. A total of 222 plant nematode species belonging to 39 genera were reported from the province, with only 94 of these species reported from the protected areas and 172 and 159 species reported from uncultivated (outside the protected areas and cultivated areas, respectively. Only nine species, Criconema silvum, Criconema talanum, Helicotylenchus marethae, Ogma dracomontanum, Ogma louisi, Ogma ueckermanni, Paralongidorus deborae, Trichodorus rinae and Xiphinemella marindae were described from protected areas, whilst O. dracomontanum, P. deborae and T. rinae were subsequently also reported from other provinces. Conservation implications: A higher degree of diversity of nematodes was observed in the unprotected areas of the province. The observation suggests that nematode fauna, and by implication also other invertebrates, are not adequately protected.

  15. Bacillus sphaericus in the adults of Culex quinquefasciatus mosquitoes emerged from treated larvae and its effect on development of the filarial parasite, Wuchereria bancrofti.

    Science.gov (United States)

    Paily, K P; Geetha, I; Kumar, B A; Balaraman, K

    2012-06-01

    Bacillus sphaericus is a bio-control agent effective against Culex quinquefasciatus, the vector of bancroftian filariasis. Apart from its larvicidal effect, there are reports of reduced infection of filarial parasites in mosquitoes exposed to it. In the present study, adults of Cx. quinquefasciatus emerged from B. sphaericus treated larvae were fed on blood samples positive for microfilariae of Wuchereria bancrofti and examined at various time intervals to assess the infection level. The rate of infection was reduced from 95% on day 1 post-feeding to 75% on day 13, when fed with blood sample containing 41 mf/20 μl. The mean parasite burden was also reduced from 4.9 per mosquito on day 1 to 2.15 on day 13. When fed with another sample (30 mf/20 μl), the infection was reduced from 100% on day 1 to 80% on day 13. Reduction in parasite burden was 4.0 to 1.75. Abnormally developed second-stage larvae of the parasite were seen in treated mosquitoes. Thus, the results indicated adverse effect of B. sphaericus treatment on infection and development of the filarial parasite in mosquitoes. The possible reason for the parasite regulation was studied through the assessment of the carryover of the bacterium as well as its toxins to the surviving mosquitoes. The presence of B. sphaericus was determined through plating of homogenate of survived mosquitoes on NYSM agar. Toxic protein was detected through immunoblotting. The bacterium as well as its 41.9-kDa toxic protein was found to be transmitted from larvae to adults and affected the parasite development, directly by the toxin or indirectly by eliciting humoral immune response of the mosquito.

  16. Colorimetric tests for diagnosis of filarial infection and vector surveillance using non-instrumented nucleic acid loop-mediated isothermal amplification (NINA-LAMP.

    Directory of Open Access Journals (Sweden)

    Catherine B Poole

    Full Text Available Accurate detection of filarial parasites in humans is essential for the implementation and evaluation of mass drug administration programs to control onchocerciasis and lymphatic filariasis. Determining the infection levels in vector populations is also important for assessing transmission, deciding when drug treatments may be terminated and for monitoring recrudescence. Immunological methods to detect infection in humans are available, however, cross-reactivity issues have been reported. Nucleic acid-based molecular assays offer high levels of specificity and sensitivity, and can be used to detect infection in both humans and vectors. In this study we developed loop-mediated isothermal amplification (LAMP tests to detect three different filarial DNAs in human and insect samples using pH sensitive dyes for enhanced visual detection of amplification. Furthermore, reactions were performed in a portable, non-instrumented nucleic acid amplification (NINA device that provides a stable heat source for LAMP. The efficacy of several strand displacing DNA polymerases were evaluated in combination with neutral red or phenol red dyes. Colorimetric NINA-LAMP assays targeting Brugia Hha I repeat, Onchocerca volvulus GST1a and Wuchereria bancrofti LDR each exhibit species-specificity and are also highly sensitive, detecting DNA equivalent to 1/10-1/5000th of one microfilaria. Reaction times varied depending on whether a single copy gene (70 minutes, O. volvulus or repetitive DNA (40 min, B. malayi and W. bancrofti was employed as a biomarker. The NINA heater can be used to detect multiple infections simultaneously. The accuracy, simplicity and versatility of the technology suggests that colorimetric NINA-LAMP assays are ideally suited for monitoring the success of filariasis control programs.

  17. Excretory/secretory products of anisakid nematodes

    DEFF Research Database (Denmark)

    Mehrdana, Foojan; Buchmann, Kurt

    2017-01-01

    Parasites from the family Anisakidae are widely distributed in marine fish populations worldwide and mainly nematodes of the three genera Anisakis, Pseudoterranova and Contracaecum have attracted attention due to their pathogenicity in humans. Their life cycles include invertebrates and fish...... as intermediate or transport hosts and mammals or birds as final hosts. Human consumption of raw or underprocessed seafood containing third stage larvae of anisakid parasites may elicit a gastrointestinal disease (anisakidosis) and allergic responses. Excretory and secretory (ES) compounds produced...... by the parasites are assumed to be key players in clinical manifestation of the disease in humans, but the molecules are likely to play a general biological role in invertebrates and lower vertebrates as well. ES products have several functions during infection, e.g. penetration of host tissues and evasion of host...

  18. Variation in estuarine littoral nematode populations over three spatial scales

    Science.gov (United States)

    Hodda, M.

    1990-04-01

    The population characteristics of the nematode fauna from five replicate cores taken over four seasons at nine sites within mangroves, at three different estuaries on the south-east coast of Australia, are compared. Using cluster analysis, principal co-ordinate analysis and other statistical techniques, the variation in nematode populations is identified as arising from several sources: temperature changes between the more northerly and southerly estuaries (5%); changes in grain size and organic content of the sediment between sites (22%); changes between sites in the frequency of samples containing certain types of food, particularly associated with pools of water and surface topography (30%); stochastic changes in nematode populations within individual samples, probably caused by small scale spatial and temporal variability in food sources (35%); and seasonal changes at all the sites and estuaries (8%). The implications of this pattern of variation for the biology of the nematodes is discussed.

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

    Science.gov (United States)

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

    2017-07-01

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

  20. Transgenesis in parasitic nematodes: building a better array

    Science.gov (United States)

    Lok, James B.

    2011-01-01

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

  1. Ecostructuring of marine nematode communities by submarine groundwater discharge.

    Science.gov (United States)

    Grzelak, Katarzyna; Tamborski, Joseph; Kotwicki, Lech; Bokuniewicz, Henry

    2018-05-01

    Inputs of submarine groundwater discharge (SGD) to the coastal ocean may alter local and regional-scale biology. Here, we report on nematode assemblages along the north shore of Long Island, NY. We test if nematode communities differed between sites impacted by mixed fresh-saline SGD and where SGD is exclusively saline. Diversity of nematodes was low at sites impacted by fresh SGD and communities were dominated by a few opportunistic genera. Moreover, a set of typical freshwater nematode genera restricted to impacted sites was observed. Their presence in the marine coastal zone is exceptional and underlines the structuring role that fresh SGD plays in the local ecosystem. Saline SGD structured nematode assemblages differently compared to sites impacted by fresh SGD. The number of nematode genera was markedly higher at saline SGD sites, with a different community structure. This study highlights the importance to which inputs of fresh SGD may have on local ecosystem diversity in marine coastal environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Targeted mutagenesis in a human-parasitic nematode.

    Directory of Open Access Journals (Sweden)

    Spencer S Gang

    2017-10-01

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

  3. Communities of terrestrial nematodes after different approaches to heathland restoration

    Science.gov (United States)

    Radochova, Petra; Frouz, Jan

    2016-04-01

    Since the 20th century, the distribution of European heathlands rapidly decreased due to agricultural intensification, heavy use of artificial fertilizers or acidification (Aerts & Heil, 1993). Therefore, various attempts of heathland restoration are under way in these days. Analysis of nematode community composition can be one of the tools suitable for succession evaluation (Ferris et al., 2001). In 2011, 2013 and 2014, soil samples were collected from heathland restoration experiment (launched in 2011) where different restoration methods were applied in a 3 × 3 factorial experiment; existing heathlands were also sampled to identify the target community both in dry and wet heathland. A total of 60 samples of extracted nematodes were analysed for absolute abundance, trophic groups, and genera dominance. Various indices were calculated to describe the nematode community. We were able to prove faster development of wet heathlands towards the target community. However, because of large data variability, there was no significant difference between treatments. Development of wet and dry heathlands differed also in increased proportion of omniphagous nematodes in 2013 and predators in 2014 in dry heathlands. After three years of heathland restoration, nematode community has not yet reached parameters of the target community. References Aerts, R., Heil, G. W., 1993. Heathlands: patterns and processes in a changing environment, 1st ed, Geobotany: 20. Springer Netherlands, Dordrecht, p. 229. Ferris, H., Bongers, T., De Goede, R. G. M., 2001. A framework for soil food web diagnostics: Extension of the nematode faunal analysis oncept. Appl. Soil Ecol. 18, 13-29.

  4. Plant elicitor peptides promote plant defences against nematodes in soybean.

    Science.gov (United States)

    Lee, Min Woo; Huffaker, Alisa; Crippen, Devany; Robbins, Robert T; Goggin, Fiona L

    2018-04-01

    Plant elicitor peptides (Peps) are widely distributed among angiosperms, and have been shown to amplify immune responses in multiple plant families. Here, we characterize three Peps from soybean (Glycine max) and describe their effects on plant defences against two damaging agricultural pests, the root-knot nematode (Meloidogyne incognita) and the soybean cyst nematode (Heterodera glycines). Seed treatments with exogenous GmPep1, GmPep2 or GmPep3 significantly reduced the reproduction of both nematodes. Pep treatment also protected plants from the inhibitory effects of root-knot nematodes on above-ground growth, and up-regulated basal expression levels of nematode-responsive defence genes. GmPep1 induced the expression of its propeptide precursor (GmPROPEP1), a nucleotide-binding site leucine-rich repeat protein (NBS-LRR), a pectin methylesterase inhibitor (PMEI), Respiratory Burst Oxidase Protein D (RBOHD) and the accumulation of reactive oxygen species (ROS) in leaves. In addition, GmPep2 and GmPep3 seed treatments up-regulated RBOHD expression and ROS accumulation in roots and leaves. These results suggest that GmPeps activate plant defences through systemic transcriptional reprogramming and ROS signalling, and that Pep seed treatments represent a potential strategy for nematode management. © 2017 BSPP AND JOHN WILEY & SONS LTD.

  5. Relationship between production, nematodes and "redness" in strawberries

    Directory of Open Access Journals (Sweden)

    Paula Nogueira Curi

    2016-08-01

    Full Text Available ABSTRACT: In recent years "redness" has increasingly appeared in strawberry plants with leaves taking on a reddish color. No causal agent has been associated with plants. Since strawberries presented problems due to the incidence of nematodes, the purpose of this study was to look at the relationship between production, resistance to the Meloidogyne hapla nematode and the "redness" symptom in strawberry cultivars. Two experiments were performed, both with the 'Camino Real', 'Festival', 'Oso Grande', 'Albion' and 'Camarosa' cultivars. The first experiment was performed in the field, where the following were evaluated: strawberry production, fruit quality, macro and micronutrient contents in fruit and leaves, percentage of plant survival, incidence of nematodes, quantity of eggs in the roots and juveniles in the soil, and the incidence of Botrytis cinerea . In the second experiment, the strawberries were transplanted into pots and filled with pinus bark-based commercial substrate. Half the pots were inocculated with Meloidogyne hapla . Cultivars presented differences in fruit production and also in the incidence of "redness". Lowest performance in production was related to the high incidence of the nematode Meloidogyne hapla. 'Oso Grande' and 'Albion' presented nematode-resistant behavior. It was possible find a relationship between the incidence of the Meloidogyne hapla nematode, and the incidence of "redness" only 'Camino Real' cultivar.

  6. Primary structure of and immunoglobulin E response to the repeat subunit of gp15/400 from human lymphatic filarial parasites

    NARCIS (Netherlands)

    Paxton, W. A.; Yazdanbakhsh, M.; Kurniawan, A.; Partono, F.; Maizels, R. M.; Selkirk, M. E.

    1993-01-01

    We have isolated and sequenced clones encoding the repeated subunit of the surface-associated glycoprotein gp15/400 from the two nematode species predominantly responsible for lymphatic filariasis in humans: Brugia malayi and Wuchereria bancrofti. The amino acid sequence of the 15-kDa subunit,

  7. GABA localization in the nematode Ascaris

    Energy Technology Data Exchange (ETDEWEB)

    Guastella, J.

    1988-01-01

    A histochemical approach was used to examine the distribution of GABA-associated neurons in the nematode Ascaris, an organism whose small number of morphologically simple neurons make it an excellent preparation for analyzing neuronal phenotypes. Two GABAergic markers were examined: GABA-like immunoreactivity (GLIR), a marker for endogenous stores of GABA; and ({sup 3}H)-GABA uptake, a marker for GABA uptake sites. Strong GLIR was present in the cell bodies, neurites and commissures of dorsal and ventral inhibitory motorneurons present in this region. Strong GLIR was also present in the cell bodies and processes of the four RME neurons in the nerve ring and in several other ganglionic neurons. Staining was absent in excitatory motorneurons, in ventral cord interneurons and in muscle cells and hypodermis. GABA uptake sites were found in single neural processes in both the ventral and dorsal nerve cords. ({sup 3}H)-GABA labeling was also observed in the other two RME cells and several other cephalic neurons. Four putative cholinergic excitatory motorneurons in the retrovesicular ganglion (RVG) were heavily labeled. Ventral and dorsal nerve cord inhibitory motorneurons did not take up ({sup 3}H)-GABA. Labeling of the ventral cord excitatory motorneuron somata and cell bodies was at or slightly above background. Heavy labeling of muscle cells was also observed.

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

    DEFF Research Database (Denmark)

    Madsen, Mette Vestergård

    2004-01-01

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

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

    Science.gov (United States)

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

  10. Plant and soil nematodes from Lokchao Yangoupokpi Wildlife Sanctuary, Manipur, India

    Directory of Open Access Journals (Sweden)

    N. Mohilal

    2009-03-01

    Full Text Available In the present study soil samples were collected from Lokchao Yangoupokpi Wildlife Sanctuary to investigate about what nematode species are associated with different plant hosts. This study shows rich nematode diversity in the sanctuary.

  11. Predation rates and prey selectivity in two predacious estuarine nematode species

    NARCIS (Netherlands)

    Moens, T.; Herman, P.M.J.; Verbeeck, L.; Steyaert, M.; Vincx, M.

    2000-01-01

    Enoploides longispiculosus and Adoncholaimus fuscus are representatives of nematode genera prominent in sediments of the North Sea and adjacent estuaries. Both are predatory nematodes, although predation is facultative in the latter. The present study investigates functional responses and prey

  12. Nucleic acid transfection and transgenesis in parasitic nematodes.

    Science.gov (United States)

    Lok, James B

    2012-04-01

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

  13. The FMRFamide-like peptide family in nematodes

    Directory of Open Access Journals (Sweden)

    Katleen ePeymen

    2014-06-01

    Full Text Available In the three decades since the FMRFamide peptide was isolated from the mollusk Macrocallista nimbosa, structurally similar peptides sharing a C-terminal RFamide motif have been identified across the animal kingdom. FMRFamide-like peptides (FLPs represent the largest known family of neuropeptides in invertebrates. In the phylum Nematoda, at least 32 flp genes are classified, making the FLP system of nematodes unusually complex. The diversity of the nematode FLP complement is most extensively mapped in Caenorhabditis elegans, where over 70 FLPs have been predicted. FLPs have shown to be expressed in the majority of the 302 C. elegans neurons including interneurons, sensory and motor neurons. The vast expression of FLPs is reflected in the broad functional repertoire of nematode FLP signaling, including neuroendocrine and neuromodulatory effects on locomotory activity, reproduction, feeding, and behavior. In contrast to the many identified nematode FLPs, only few peptides have been assigned a receptor and there is the need to clarify the pathway components and working mechanisms of the FLP signaling network. Here, we review the diversity, distribution, and functions of FLPs in nematodes.

  14. Smart Parasitic Nematodes Use Multifaceted Strategies to Parasitize Plants

    Directory of Open Access Journals (Sweden)

    Muhammad A. Ali

    2017-10-01

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

  15. Organic and Inorganic Nitrogen Amendments to Soil as Nematode Suppressants

    Science.gov (United States)

    Rodríguez-Kábana, R.

    1986-01-01

    Inorganic fertilizers containing ammoniacal nitrogen or formulations releasing this form of N in the soil are most effective for suppressing nematode populations. Anhydrous ammonia has been shown to reduce soil populations of Tylenchorhynchus claytoni, Helicotylenchus dihystera, and Heterodera glycines. The rates required to obtain significant suppression of nematode populations are generally in excess of 150 kg N/ha. Urea also suppresses several nematode species, including Meloidogyne spp., when applied at rates above 300 kg N/ha. Additional available carbon must be provided with urea to permit soil microorganisms to metabolize excess N and avoid phytotoxic effects. There is a direct relation between the amount of "protein" N in organic amendments and their effectiveness as nematode population suppressants. Most nematicidal amendments are oil cakes, or animal excrements containing 2-7% (w:w) N; these materials are effective at rates of 4-10 t/ha. Organic soil amendments containing mucopolysaccharides (e.g., mycelial wastes, chitinous matter) are also effective nematode suppressants. PMID:19294153

  16. Soy desiccants herbicides acting in nematode populations on community land

    Directory of Open Access Journals (Sweden)

    Lucas Baiochi Riboldi

    2013-12-01

    Full Text Available The use of herbicides is the main method of weed control in soybeans. Desiccants are also being used routinely to anticipate the harvest and / or minimize the deterioration of seed quality. There is the possibility of direct or indirect contact with such pesticides, affect the community of nematodes in the soil. However, such effects and their magnitudes are yet to be clarified, especially in the case of selective herbicides. Thus, the objective of this study was to evaluate the use of selective herbicides in soybean on nematodes harmful to the crop. The experiment was conducted with transgenic soybean (‘M-SOY 7908RR’. The experimental design was a randomized block design with the following treatments: paraquat (400 g a.i ha-1, diquat (200 g a.i ha-1, a mixture of paraquat and diquat (300 + 150 g a.i ha-1, two doses of carfentrazone ethyl (20 g a.i ha-1 and 30 g a.i ha-1 and control (without desiccant application. The nematode community in the area was monitored in four periods. In none of those was found significant variation in the populations of nematodes harmful to soybeans, due to the application of any of desiccants. However, especially in the last sampling time, the desiccant application always resulted in increased populations of free-living nematodes and parasites those considered weak for soybean.

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

    Science.gov (United States)

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

    2015-02-01

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

  18. Respiratory nematodes in cat populations of Italy.

    Science.gov (United States)

    Di Cesare, Angela; Veronesi, Fabrizia; Grillotti, Eleonora; Manzocchi, Simone; Perrucci, Stefania; Beraldo, Paola; Cazzin, Stefania; De Liberato, Claudio; Barros, Luciano A; Simonato, Giulia; Traversa, Donato

    2015-12-01

    The occurrence of common respiratory parasites of domestic cats (the metastrongyloid "cat lungworm" Aelurostrongylus abstrusus and the trichuroid Capillaria aerophila) and of neglected respiratory nematodes of felids (Troglostrongylus brevior, Angiostrongylus chabaudi and Oslerus rostratus) was here evaluated in two and three geographical sites of Northern and Central Italy, respectively. In 2014-2015, individual fecal samples of 868 domestic cats were examined microscopically and genetically, and epidemiological data related to parasitic infections were evaluated as possible risk factors by binary logistic regression models. The most common parasite was A. abstrusus in both mono- and poli-specific infections, followed by T. brevior and C. aerophila, while cats scored negative for other parasites. Cats positive for A. abstrusus (1.9-17 % infection rate) and C. aerophila (0.9-4.8 % infection rate) were found in all examined sites, while cats scored positive for T. brevior (1-14.3 % infection rate) in four sites. Also, T. brevior was here found for the first time in a domestic cat from a mountainous area of Northern Italy. The occurrence of lungworms was statistically related to the presence of respiratory signs and more significant in cats with mixed infection by other lungworms and/or intestinal parasites. Cats living in site C of Central Italy resulted statistically more at risk of infection for lungworms than cats living in the other study sites, while animals ageing less than 1 year were at more risk for troglostrongylosis. Finally, the presence of lungworms was more significant in cats with mixed infection by other lungworms and/or intestinal parasites. These results are discussed under epidemiological and clinical points of views.

  19. A Treadmill to Localize, Exercise, and Measure the Propulsive Power of Nematodes

    Science.gov (United States)

    Yuan, Jinzhou; Chuan, Han-Sheng; Gnatt, Michael; Raizen, David; Bau, Haim

    2011-11-01

    The nematodes C. elegans is often used as model biological system to study the genetic basis of behavior, disease-progression, and aging, as well as to develop new therapies and screen drugs. On occasion, it is desirable to quantify the nematode's muscle power. Here, we present a kind of nematode treadmill. The device consists of a tapered conduit filled with aqueous solution. The conduit is subjected to a DC electric field and to pressure-driven flow directed from the narrow end. The nematode is inserted at the conduit's wide end. Directed by the electric field (through electrotaxis), the nematode swims deliberately upstream toward the negative pole. As the conduit narrows, the average fluid velocity and the drag force on the nematode increase. Eventually, the nematode arrives at an equilibrium position, at which its propulsive power balances the viscous drag force. The nematode's propulsive power is estimated with direct numerical simulations of the flow field around the nematode. The calculations utilize the experimentally imaged gait as a boundary condition. The device is useful to retain the nematode at a nearly fixed position for prolonged observations under a microscope, to keep the nematode exercising, and to estimate the nematode's power based on the conduit's width at the equilibrium position.

  20. Towards isolation of the tomato root-knot nematode resistance gene MI via positional cloning

    NARCIS (Netherlands)

    Daelen, van R.A.J.J.

    1995-01-01

    Root-knot nematodes of the genus Meloidogyne are severe pathogens of plants and worldwide they cause damage to many economically important crops like potato, rice, cotton, and tomato. So the control of nematodes and the protection of plants against nematode damage are

  1. A SNARE-like protein and biotin are implicated in soybean cyst nematode virulence

    Science.gov (United States)

    Some phytoparasitic nematodes have the ability to infect and reproduce on plants that are normally considered resistant to nematode infection. Such nematodes are referred to as virulent and the mechanisms they use to evade or suppress host plant defenses are not well understood. Here, we report the ...

  2. Mechanisms Involved in Nematode Control by Endophytic Fungi.

    Science.gov (United States)

    Schouten, Alexander

    2016-08-04

    Colonization of plants by particular endophytic fungi can provide plants with improved defenses toward nematodes. Evidently, such endophytes can be important in developing more sustainable agricultural practices. The mechanisms playing a role in this quantitative antagonism are poorly understood but most likely multifactorial. This knowledge gap obstructs the progress regarding the development of endophytes or endophyte-derived constituents into biocontrol agents. In part, this may be caused by the fact that endophytic fungi form a rather heterogeneous group. By combining the knowledge of the currently characterized antagonistic endophytic fungi and their effects on nematode behavior and biology with the knowledge of microbial competition and induced plant defenses, the various mechanisms by which this nematode antagonism operates or may operate are discussed. Now that new technologies are becoming available and more accessible, the currently unresolved mechanisms can be studied in greater detail than ever before.

  3. Nematodes of elasmobranch fishes from the southern coast of Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo Knoff

    2001-01-01

    Full Text Available New records for nematode species recovered from elasmobranch fishes in Brazil are established and new systematical arrangements proposed. Parascarophis sphyrnae Campana-Rouget, 1955 from the spiral valve of Sphyrna zygaena is referred for the first time in South America as a new host record. Procamallanus (S. pereirai Annereaux, 1946, from the spiral valve of Raja castelnaui is reported parasitizing an elasmobranch host. Nematode larvae of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are listed from the stomach and spiral valves of several hosts. Anisakidae larvae previously referred in Brazil in the genus Phocanema should be reallocated in Pseudoterranova. Nematodes of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are reported for the first time parasitizing elasmobranchs in Brazil.

  4. Nematodes of elasmobranch fishes from the southern coast of Brazil.

    Science.gov (United States)

    Knoff, M; de São Clemente, S C; Pinto, R M; Gomes, D C

    2001-01-01

    New records for nematode species recovered from elasmobranch fishes in Brazil are established and new systematical arrangements proposed. Parascarophis sphyrnae Campana-Rouget, 1955 from the spiral valve of Sphyrna zygaena is referred for the first time in South America as a new host record. Procamallanus (S.) pereirai Annereaux, 1946, from the spiral valve of Raja castelnaui is reported parasitizing an elasmobranch host. Nematode larvae of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are listed from the stomach and spiral valves of several hosts. Anisakidae larvae previously referred in Brazil in the genus Phocanema should be reallocated in Pseudoterranova. Nematodes of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are reported for the first time parasitizing elasmobranchs in Brazil.

  5. Small-molecule pheromones and hormones controlling nematode development.

    Science.gov (United States)

    Butcher, Rebecca A

    2017-05-17

    The existence of small-molecule signals that influence development in Caenorhabditis elegans has been known for several decades, but only in recent years have the chemical structures of several of these signals been established. The identification of these signals has enabled connections to be made between these small molecules and fundamental signaling pathways in C. elegans that influence not only development but also metabolism, fertility, and lifespan. Spurred by these important discoveries and aided by recent advances in comparative metabolomics and NMR spectroscopy, the field of nematode chemistry has the potential to expand dramatically in the coming years. This Perspective will focus on small-molecule pheromones and hormones that influence developmental events in the nematode life cycle (ascarosides, dafachronic acids, and nemamides), will cover more recent work regarding the biosynthesis of these signals, and will explore how the discovery of these signals is transforming our understanding of nematode development and physiology.

  6. Statistical and Economic Techniques for Site-specific Nematode Management.

    Science.gov (United States)

    Liu, Zheng; Griffin, Terry; Kirkpatrick, Terrence L

    2014-03-01

    Recent advances in precision agriculture technologies and spatial statistics allow realistic, site-specific estimation of nematode damage to field crops and provide a platform for the site-specific delivery of nematicides within individual fields. This paper reviews the spatial statistical techniques that model correlations among neighboring observations and develop a spatial economic analysis to determine the potential of site-specific nematicide application. The spatial econometric methodology applied in the context of site-specific crop yield response contributes to closing the gap between data analysis and realistic site-specific nematicide recommendations and helps to provide a practical method of site-specifically controlling nematodes.

  7. Statistical and Economic Techniques for Site-specific Nematode Management

    Science.gov (United States)

    Liu, Zheng; Griffin, Terry; Kirkpatrick, Terrence L.

    2014-01-01

    Recent advances in precision agriculture technologies and spatial statistics allow realistic, site-specific estimation of nematode damage to field crops and provide a platform for the site-specific delivery of nematicides within individual fields. This paper reviews the spatial statistical techniques that model correlations among neighboring observations and develop a spatial economic analysis to determine the potential of site-specific nematicide application. The spatial econometric methodology applied in the context of site-specific crop yield response contributes to closing the gap between data analysis and realistic site-specific nematicide recommendations and helps to provide a practical method of site-specifically controlling nematodes. PMID:24643451

  8. Stem nematode counteracts plant resistance of aphids in alfalfa, Medicago sativa.

    Science.gov (United States)

    Ramirez, Ricardo A; Spears, Lori R

    2014-10-01

    Plants are exploited by a diverse community of insect herbivores and phytopathogens that interact indirectly through plant-mediated interactions. Generally, plants are thought to respond to insects and pathogens through different defensive signaling pathways. As plants are selected for resistance to one phytophagous organism type (insect vs. pathogen) in managed systems, it is not clear how this selection may affect community interactions. This study examined the effect of nematode-resistant varieties on aphid (Acyrthosiphon pisum) suppression, and then determined how infection by the stem nematode, Ditylenchus dipsaci, mediated ecological effects on aphids and on plant defense proteins. Four alfalfa (Medicago sativa) varieties were selected with resistance to nematodes only (+,-), aphids only (-,+), nematodes and aphids (+,+), and susceptibility to nematodes and aphids (-,-). Field and greenhouse experiments were conducted to isolate the effect of nematode infection and aphid abundance on each variety. We found that varieties resistant to nematode, regardless of aphid resistance, had the lowest aphid counts, suggesting possible cross-resistance. Aphid abundance, however, increased when plants were exposed to nematodes. Resistant varieties were associated with elevated saponins but these compounds were not affected by insect or pathogen feeding. Concentrations of peroxidases and trypsin inhibitors, however, were increased in nematode resistant varieties when exposed to nematodes and aphids, respectively. The patterns of plant defense were variable, and a combination of resistance traits and changes in nutrient availability may drive positive interactions between nematodes and aphids aboveground.

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

    Science.gov (United States)

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

    2016-07-27

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

  10. High-throughput sequencing of nematode communities from total soil DNA extractions

    DEFF Research Database (Denmark)

    Sapkota, Rumakanta; Nicolaisen, Mogens

    2015-01-01

    nematodes without the need for enrichment was developed. Using this strategy on DNA templates from a set of 22 agricultural soils, we obtained 64.4% sequences of nematode origin in total, whereas the remaining sequences were almost entirely from other metazoans. The nematode sequences were derived from...... in previous sequence-based studies are not nematode specific but also amplify other groups of organisms such as fungi and plantae, and thus require a nematode enrichment step that may introduce biases. Results: In this study an amplification strategy which selectively amplifies a fragment of the SSU from...... a broad taxonomic range and most sequences were from nematode taxa that have previously been found to be abundant in soil such as Tylenchida, Rhabditida, Dorylaimida, Triplonchida and Araeolaimida. Conclusions: Our amplification and sequencing strategy for assessing nematode diversity was able to collect...

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

    Czech Academy of Sciences Publication Activity Database

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

    2006-01-01

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

  12. Systemic induced tolerance against root-knot nematodes in rice

    African Journals Online (AJOL)

    user

    c Institute of Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology, P.O.. Box 62000, City ... of information from fundamental research in order to get more insight on the interaction between these nematodes ..... 1200TM Automated PCR Set up robot (Corbett Life Science, 2009). All PCR samples ...

  13. Genetic diversity of the potato cyst nematode in the Netherlands

    NARCIS (Netherlands)

    Folkertsma, R.T.

    1997-01-01


    The potato cyst nematodes Globodera rostochiensis (Woll.) Skarbilovich and G. pallida (Stone) originate from the Andes region in South America and have been introduced into Western Europe since 1850. Both species are

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

    African Journals Online (AJOL)

    ACSS

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

  15. Occurence of Anisakids nematodes on Frozen Hake ( Merluccius ...

    African Journals Online (AJOL)

    Samples of the frozen hake were obtained once a week as corresponding to supply in Yenagoa Market Bayelsa State ,Nigeria . From every supply of 10 cartons, 10 pieces of hake were examined for the presence of Anisakids nematodes .The incidence was concluded after sampling continuously every week for 8weeks ...

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  17. Prevalence and risk factors for intestinal nematode infections in ...

    African Journals Online (AJOL)

    A community-based cross-sectional study was conducted between November 2010 and February 2011 to assess the prevalence of intestinal nematode infections among children aged 1 – 14 years living in two communities of rural Ebonyi State, Nigeria, characterize the risk factors for infection and develop environmental ...

  18. Prevalence and diversity of gastrointestinal nematodes of cattles in ...

    African Journals Online (AJOL)

    A total of 384 faecal samples for the coproscopic examination were collected and processed using direct faecal floatation method in parasitology laboratory of Jimma University, School of Veterinary medicine. Out of the total sampled cattle, 190 (49.5%) had a gastrointestinal nematode infection. Coprological investigation ...

  19. Faecal nematode egg counts in Merino sheep following natural ...

    African Journals Online (AJOL)

    Unknown

    This study reports line differences in faecal nematode egg counts in strains of Merino sheep after natural challenge, and genetic (co)variances of egg counts with other traits of economic importance. Material and Methods. Sheep from a Merino selection experiment on the Tygerhoek experimental farm in the Southern Cape.

  20. Maintenance of genetic variation in automictic root-knot nematodes

    NARCIS (Netherlands)

    Van Der Beek, J. G. ( Hans); Punacker, Laas P.

    2008-01-01

    Differences in amplified fragment length polymorphisms (AFLP) between isolates and between mono-female lines of facultative automictic Meloidogyne hapla race A and obligate apomictic M incognita were determined to test the hypothesis that inverted meiosis occurs. DNA of the parthenogenetic nematode

  1. Mechanisms Involved in Nematode Control by Endophytic Fungi

    NARCIS (Netherlands)

    Schouten, Sander

    2016-01-01

    Colonization of plants by particular endophytic fungi can provide plants with improved defenses toward nematodes. Evidently, such endophytes can be important in developing more sustainable agricultural practices. The mechanisms playing a role in this quantitative antagonism are poorly understood

  2. Nematode Parasitemia in School aged Children in Sapele, Delta ...

    African Journals Online (AJOL)

    Two hundred (200) faecal samples were collected from school aged children in four randomly selected primary schools in Sapele metropolis of Delta State, Nigeria, to determine gastrointestinal nematode parasitemia. The formal-ether concentration technique was used to analyse the specimens and data obtained revealed ...

  3. Risk factors associated with gastrointestinal nematode infections of ...

    African Journals Online (AJOL)

    A study was carried out in Nakuru and Mukurweini districts of Kenya to identify the risk factors associated with gastrointestinal nematode (GIN) infection in cattle on 128 dairy farms between June 16th 2010 and August 30th 2010. Faecal samples were collected from the rectum of 419 heads of cattle that were above three ...

  4. The prevalence of gastrointestinal nematode infection and their ...

    African Journals Online (AJOL)

    A cross-sectional study was conducted in Nakuru and Mukurweini districts of Kenya to estimate the prevalence of gastrointestinal nematodes (GIN) and the financial impact of such infections among smallholder dairy farms. Parasitological examination involving feacal egg count and larval culture was employed to determine ...

  5. Gastrointestinal Nematodes and Body Condition Scores of Goats ...

    African Journals Online (AJOL)

    Gastrointestinal (GI) nematodes of 210 trade goats slaughtered in Nsukka area of Enugu state and their effects on body conditions was studied between May and August, 2011. The body condition of each goat were determined and scored on a scale of 1 – 5. Faecal samples were then collected from the goats before ...

  6. Efficacy of two anthelmintics against gastrointestinal nematodes in ...

    African Journals Online (AJOL)

    A study was conducted to determine the efficacy of albendazole (ABZ) and ivermectin (IVM) against gastrointestinal nematodes (GIN) in naturally infected goats in the pastoral region of Karamoja, Uganda. Fifty four (54) small East African goats (female = 36, male = 18), of 4-6 months and from 18 flocks, were allocated to ...

  7. Seasonal patterns of gastrointestinal nematode infections in sheep ...

    African Journals Online (AJOL)

    The seasonal patterns of trichostrongylid nematode infections in Dorper yearlings in a semi-arid area of Kajiado District, Kenya were investigated by analysis faecal egg output, herbage infectivity and post-mortem worm recovery. Rectal faecal samples from 60 animals as well as herbage samples from their grazing fields ...

  8. Field study on nematode resistance in Nelore-breed cattle

    NARCIS (Netherlands)

    Bricarello, P A; Zaros, L G; Coutinho, L L; Rocha, R A; Kooyman, F N J; De Vries, E; Gonçalves, J R S; Lima, L G; Pires, A V; Amarante, A F T

    2007-01-01

    The present study evaluated Nelore cattle with different degrees of resistance to natural infections by gastrointestinal nematodes. One hundred weaned male cattle, 11-12 months of age, were kept on the same pasture and evaluated from October 2003 to February 2004. Faecal and blood samples were

  9. A survey of gastrointestinal nematodes in soil samples in Ibadan ...

    African Journals Online (AJOL)

    This was to determine the comparative level of soil contamination by these helminthes. Out of the 60 top and deep soil samples collected from high-density areas, 12(20%) were positive for various pathogenic gastrointestinal nematodes. They include Ascaris sp., Toxocara canis, Trichuris trichiura, Strongyloides stercoralis, ...

  10. 5 Spatial Distribution of Nematodes at Organic.cdr

    African Journals Online (AJOL)

    user

    live in the thin films of water surrounding soil particles because water aids their mobility (Freckman ... Geostatistics can be used to analyse and quantify spatial autocorrelation by distance and direction (Evans et al., 1999). Geostatistical analysis in previous studies has shown that field-scale autocorrelation in nematode ...

  11. Nematodes and Weeds Control Effects of Pueraria phaseoloides ...

    African Journals Online (AJOL)

    The yield of plantain (Musa spp., AAB Simmonds) declines sharply after 1–2 years of cropping in West and Central Africa, due mainly to weeds and nematodes. A trial was carried out from January 2002 to October 2005 under two land-use systems (LUS) comprising 4–5 year-old bush fallow, dominated by Chromolaena ...

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

    African Journals Online (AJOL)

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

  13. testinal nematodes of sheep owned by smallholder farmers in ...

    African Journals Online (AJOL)

    analyzed using the formula described by Dash et al. (1988), arithmetic means, and Presidente (1985), geometric means, of FECR. Nematodes egg counts were subject to logarithmic transformation, [log (x+1)], to stabilize variances (Mar- tin, 1982) and expressed as geometric means for the groups; and also for analy-.

  14. Effect of tanniniferous browse meal on nematode faecal egg counts ...

    African Journals Online (AJOL)

    The effect of tanniniferous browse meal on faecal egg counts (FEC) and intestinal worm burdens was investigated in sheep and goats infested experimentally with gastrointestinal nematodes. Initially, leaves of different browse tree species were assayed for condensed tannin (CT) content using a colorimetric method to ...

  15. Analysis of nematode infection levels among indoor pigs in Thika ...

    African Journals Online (AJOL)

    The infection levels of various species of nematode infection were studied in 35 indoor pig herds in Thika district, Kenya. Faecal samples were ... To reduce these costs, it is recommended that animals should be treated after faecal examination and laboratory determination of the EPG levels.. Kenya Veterinarian Vol.

  16. Population and molecular genetics of root-knot nematodes

    NARCIS (Netherlands)

    Dautova, M.

    2001-01-01

    This thesis describes studies of root-knot nematodes Meloidogyne spp. - an economically important pest in agriculture - using population and molecular genetics. Variability in virulence to Mi bearing tomato genotypes is shown for

  17. Foraging behavior and virulence of some entomopathogenic nematodes

    Directory of Open Access Journals (Sweden)

    Manana A. Lortkipanidze

    2016-06-01

    Full Text Available At present the biological control as a pest control technology is becoming more desirable. Biological formulations on basis of entomopathogenic nematodes are one of the effective means for the protection of agricultural and forest plants from harmful insects. Nowadays, the use of entomopathogenic nematodes as biological control agents is a key component in IPM system. The foraging strategies of entomopathogenic nematodes (EPNs vary between species. This variation is consistent with use of different foraging strategies between ambush, cruise and intermediate to find their host insects. In order to ambush prey, some species of EPNs nictate, or raise their bodies of the soil surface so they are better poised to attach passing insects, other species adopt a cruising strategy and rarely nictate. Some species adopt an intermediate strategy between ambush and cruise. We compared in laboratory the foraging strategies of the entomopathogenic nematode species: Steinernema carpocapsae, Heterorhabditis bacteriophora and the recently described species Steinernema tbilisiensis and assessed their virulence against mealworm beetle, Tenebrio molitor L. (Coleoptera: Tenebrionidae. The tests showed that S. tbilisiensis adopts both foraging strategies.

  18. The dynamics of nematode infections of farmed ruminants

    NARCIS (Netherlands)

    Roberts, M.G.; Heesterbeek, J.A.P.

    1995-01-01

    In this paper the dynamics and control of nematode parasites of farmed ruminants are discussed via a qualitative analysis of a differential equation model. To achieve this a quantity, 'the basic reproduction quotient' (Q0), whose definition coincides with previous definitions of R0 for

  19. A critique of current methods in nematode taxonomy | Abebe ...

    African Journals Online (AJOL)

    In the past few decades, there have been efforts to integrate molecular methods and digital 3D image-capturing technology in nematode taxonomy, the former to enhance the accuracy of identification of such a taxonomically challenging group and the latter to communicate morphological data. While the employment of ...

  20. Reproduction of root knot nematode (Meloidogyne incognita) on Bt ...

    African Journals Online (AJOL)

    SARAH

    2013-09-30

    Sep 30, 2013 ... ABSTRACT. Objective: The sedentary endoparasite Meloidogyne incognita is an important plant parasitic nematode that infects cotton causing significant yield losses. The objective of this study was to evaluate reproduction of M. incognita in Bt cotton (06Z604D), isoline (99M03) and HART 89M (local ...

  1. Gastrointestinal nematodes of donkeys in and around Alage, South ...

    African Journals Online (AJOL)

    of lugol's iodine was added to the sediment to differentiate the larvae which stains the free living nematode yellow, while parasitic 3rd stage larvae remain unstained. The larvae was then identified under low power microscopy (10x objective), based on the shape and number of gut cells, relative size of sheath tail and shape ...

  2. Profiling nematode communities in unmanaged flowerbed and agricultural field soils in Japan by DNA barcode sequencing.

    Directory of Open Access Journals (Sweden)

    Hisashi Morise

    Full Text Available Soil nematodes play crucial roles in the soil food web and are a suitable indicator for assessing soil environments and ecosystems. Previous nematode community analyses based on nematode morphology classification have been shown to be useful for assessing various soil environments. Here we have conducted DNA barcode analysis for soil nematode community analyses in Japanese soils. We isolated nematodes from two different environmental soils of an unmanaged flowerbed and an agricultural field using the improved flotation-sieving method. Small subunit (SSU rDNA fragments were directly amplified from each of 68 (flowerbed samples and 48 (field samples isolated nematodes to determine the nucleotide sequence. Sixteen and thirteen operational taxonomic units (OTUs were obtained by multiple sequence alignment from the flowerbed and agricultural field nematodes, respectively. All 29 SSU rDNA-derived OTUs (rOTUs were further mapped onto a phylogenetic tree with 107 known nematode species. Interestingly, the two nematode communities examined were clearly distinct from each other in terms of trophic groups: Animal predators and plant feeders were markedly abundant in the flowerbed soils, in contrast, bacterial feeders were dominantly observed in the agricultural field soils. The data from the flowerbed nematodes suggests a possible food web among two different trophic nematode groups and plants (weeds in the closed soil environment. Finally, DNA sequences derived from the mitochondrial cytochrome oxidase c subunit 1 (COI gene were determined as a DNA barcode from 43 agricultural field soil nematodes. These nematodes were assigned to 13 rDNA-derived OTUs, but in the COI gene analysis were assigned to 23 COI gene-derived OTUs (cOTUs, indicating that COI gene-based barcoding may provide higher taxonomic resolution than conventional SSU rDNA-barcoding in soil nematode community analysis.

  3. Population development of beet cyst nematodes and their damage potential to sugar beets under different temperature regimes

    OpenAIRE

    Bart Vandenbossche; Björn Niere; Stefan Vidal

    2011-01-01

    _Heterodera schachtii_, the white beet cyst nematode, is considered as one of the most important nematode pests on sugar beet and is present in most sugar-beet growing areas. The yellow beet cyst nematode, _Heterodera betae_, is less prevalent but has also been found damaging beet crops. However, knowledge about the damage potential and population dynamics of the yellow beet cyst nematode is limited. The amount of damage inflicted by nematodes is dependent on different factors. An important f...

  4. Activated entomopathogenic nematode infective juveniles release lethal venom proteins.

    Directory of Open Access Journals (Sweden)

    Dihong Lu

    2017-04-01

    Full Text Available Entomopathogenic nematodes (EPNs are unique parasites due to their symbiosis with entomopathogenic bacteria and their ability to kill insect hosts quickly after infection. It is widely believed that EPNs rely on their bacterial partners for killing hosts. Here we disproved this theory by demonstrating that the in vitro activated infective juveniles (IJs of Steinernema carpocapsae (a well-studied EPN species release venom proteins that are lethal to several insects including Drosophila melanogaster. We confirmed that the in vitro activation is a good approximation of the in vivo process by comparing the transcriptomes of individual in vitro and in vivo activated IJs. We further analyzed the transcriptomes of non-activated and activated IJs and revealed a dramatic shift in gene expression during IJ activation. We also analyzed the venom proteome using mass spectrometry. Among the 472 venom proteins, proteases and protease inhibitors are especially abundant, and toxin-related proteins such as Shk domain-containing proteins and fatty acid- and retinol-binding proteins are also detected, which are potential candidates for suppressing the host immune system. Many of the venom proteins have conserved orthologs in vertebrate-parasitic nematodes and are differentially expressed during IJ activation, suggesting conserved functions in nematode parasitism. In summary, our findings strongly support a new model that S. carpocapsae and likely other Steinernema EPNs have a more active role in contributing to the pathogenicity of the nematode-bacterium complex than simply relying on their symbiotic bacteria. Furthermore, we propose that EPNs are a good model system for investigating vertebrate- and human-parasitic nematodes, especially regarding the function of excretory/secretory products.

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

    International Nuclear Information System (INIS)

    Galle, F.; Loosjes, M.

    1987-01-01

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

  6. Damage-associated responses of the host contribute to defence against cyst nematodes but not root-knot nematodes

    NARCIS (Netherlands)

    Shah, Syed Jehangir; Anjam, Muhammad Shahzad; Mendy, Badou; Anwer, Muhammad Arslan; Habash, Samer S.; Lozano-Torres, Jose L.; Grundler, Florian M.W.; Siddique, Shahid

    2017-01-01

    When nematodes invade and subsequently migrate within plant roots, they generate cell wall fragments (in the form of oligogalacturonides; OGs) that can act as damage-associated molecular patterns and activate host defence responses. However, the molecular mechanisms mediating damage responses in

  7. Circulating filarial antigen in the hydrocele fluid from individuals living in a bancroftian filariasis area - Recife, Brazil : detected by the monoclonal antibody Og4C3-assay

    Directory of Open Access Journals (Sweden)

    Rocha Abraham

    2004-01-01

    Full Text Available The purpose of this study was to examine the circulating filarial antigen (CFA detected by the monoclonal antibody (mAb Og4C3-ELISA in paired samples of serum and hydrocele fluid from 104 men with hydrocele, living in an endemic area of Wuchereria bancrofti. Nocturnal blood specimens were filtered and examined for microfilariae (MF and ultrasound was used in order to identify the presence of adult worms (the filaria dance sign - FDS in the lymphatic vessels of the scrotal area. Four groups were selected according to their parasitological status: group I - 71 MF- and FDS-; group II - 21 MF+ and FDS+; group III - 10 MF- and FDS+ and group IV- 2 MF+ and FDS-. CFA was identified simultaneously (fluid and serum in 11 (15.5%, 21 (100%, 3 (30%, and 1 (50% in groups I, II, III, and IV, respectively. In despite of high CFA+ level (antigen Og4C3 units/ml, the Geometrical Mean (GM = 2696 in the sera of these 36/104 paired samples, when compared to the hydrocele fluid, (GM = 1079, showed a very good correlation between the CFA level in the serum and CFA level in the fluid (r = 0.731. CFA level in the serum of the 23 microfilaremics (groups II and IV was extremely high (GM = 4189 and was correlated with MF density (r = 0.442. These findings report for the first time the potential alternative use of the hydrocele fluid to investigate CFA using the mAb Og4C3-ELISA.

  8. A Large Collection of Novel Nematode-Infecting Microsporidia and Their Diverse Interactions with Caenorhabditis elegans and Other Related Nematodes

    Science.gov (United States)

    Zhang, Gaotian; Sachse, Martin; Prevost, Marie-Christine; Troemel, Emily R.; Félix, Marie-Anne

    2016-01-01

    Microsporidia are fungi-related intracellular pathogens that may infect virtually all animals, but are poorly understood. The nematode Caenorhabditis elegans has recently become a model host for studying microsporidia through the identification of its natural microsporidian pathogen Nematocida parisii. However, it was unclear how widespread and diverse microsporidia infections are in C. elegans or other related nematodes in the wild. Here we describe the isolation and culture of 47 nematodes with microsporidian infections. N. parisii is found to be the most common microsporidia infecting C. elegans in the wild. In addition, we further describe and name six new species in the Nematocida genus. Our sampling and phylogenetic analysis further identify two subclades that are genetically distinct from Nematocida, and we name them Enteropsectra and Pancytospora. Interestingly, unlike Nematocida, these two genera belong to the main clade of microsporidia that includes human pathogens. All of these microsporidia are horizontally transmitted and most specifically infect intestinal cells, except Pancytospora epiphaga that replicates mostly in the epidermis of its Caenorhabditis host. At the subcellular level in the infected host cell, spores of the novel genus Enteropsectra show a characteristic apical distribution and exit via budding off of the plasma membrane, instead of exiting via exocytosis as spores of Nematocida. Host specificity is broad for some microsporidia, narrow for others: indeed, some microsporidia can infect Oscheius tipulae but not its sister species Oscheius sp. 3, and conversely some microsporidia found infecting Oscheius sp. 3 do not infect O. tipulae. We also show that N. ausubeli fails to strongly induce in C. elegans the transcription of genes that are induced by other Nematocida species, suggesting it has evolved mechanisms to prevent induction of this host response. Altogether, these newly isolated species illustrate the diversity and ubiquity of

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

    Science.gov (United States)

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

    2018-01-01

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

  10. Fast, automated measurement of nematode swimming (thrashing without morphometry

    Directory of Open Access Journals (Sweden)

    Sattelle David B

    2009-07-01

    Full Text Available Abstract Background The "thrashing assay", in which nematodes are placed in liquid and the frequency of lateral swimming ("thrashing" movements estimated, is a well-established method for measuring motility in the genetic model organism Caenorhabditis elegans as well as in parasitic nematodes. It is used as an index of the effects of drugs, chemicals or mutations on motility and has proved useful in identifying mutants affecting behaviour. However, the method is laborious, subject to experimenter error, and therefore does not permit high-throughput applications. Existing automation methods usually involve analysis of worm shape, but this is computationally demanding and error-prone. Here we present a novel, robust and rapid method of automatically counting the thrashing frequency of worms that avoids morphometry but nonetheless gives a direct measure of thrashing frequency. Our method uses principal components analysis to remove the background, followed by computation of a covariance matrix of the remaining image frames from which the interval between statistically-similar frames is estimated. Results We tested the performance of our covariance method in measuring thrashing rates of worms using mutations that affect motility and found that it accurately substituted for laborious, manual measurements over a wide range of thrashing rates. The algorithm used also enabled us to determine a dose-dependent inhibition of thrashing frequency by the anthelmintic drug, levamisole, illustrating the suitability of the system for assaying the effects of drugs and chemicals on motility. Furthermore, the algorithm successfully measured the actions of levamisole on a parasitic nematode, Haemonchus contortus, which undergoes complex contorted shapes whilst swimming, without alterations in the code or of any parameters, indicating that it is applicable to different nematode species, including parasitic nematodes. Our method is capable of analyzing a 30 s movie in

  11. Identification, Validation and Utilization of Novel Nematode-Responsive Root-Specific Promoters in Arabidopsis for Inducing Host-Delivered RNAi Mediated Root-Knot Nematode Resistance

    Directory of Open Access Journals (Sweden)

    Atul Kakrana

    2017-12-01

    Full Text Available The root-knot nematode (RKN, Meloidogyne incognita, is an obligate, sedentary endoparasite that infects a large number of crops and severely affects productivity. The commonly used nematode control strategies have their own limitations. Of late, RNA interference (RNAi has become a popular approach for the development of nematode resistance in plants. Transgenic crops capable of expressing dsRNAs, specifically in roots for disrupting the parasitic process, offer an effective and efficient means of producing resistant crops. We identified nematode-responsive and root-specific (NRRS promoters by using microarray data from the public domain and known conserved cis-elements. A set of 51 NRRS genes was identified which was narrowed down further on the basis of presence of cis-elements combined with minimal expression in the absence of nematode infection. The comparative analysis of promoters from the enriched NRRS set, along with earlier reported nematode-responsive genes, led to the identification of specific cis-elements. The promoters of two candidate genes were used to generate transgenic plants harboring promoter GUS constructs and tested in planta against nematodes. Both promoters showed preferential expression upon nematode infection, exclusively in the root in one and galls in the other. One of these NRRS promoters was used to drive the expression of splicing factor, a nematode-specific gene, for generating host-delivered RNAi-mediated nematode-resistant plants. Transgenic lines expressing dsRNA of splicing factor under the NRRS promoter exhibited upto a 32% reduction in number of galls compared to control plants.

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

    Science.gov (United States)

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

    2017-04-01

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

  13. Optimizing the application of entomopathogenic nematodes: experimental set-up.

    Science.gov (United States)

    Brusselman, E; Steurbaut, W; Sonck, B

    2007-01-01

    The complex issue concerning the spray application of Entomopathogenic Nematodes (EPNs) with a hydraulic sprayer is still not solved. This research project focuses on the effect of spray application technique on the viability and deposition of EPNs. In this paper the experimental set-up used for this evaluation is described. A modular spray application system has been developed and is currently used to evaluate the effect of different parts of a sprayer on the viability of the EPNs. Based on the results of experiments using this modular spray application system, recommendations regarding pump type, mixing system, nozzle type and filter size will be formulated. Because of the large number of experiments in this research project, an image analysis system for the determination of the viability of the nematodes is developed. This paper describes two experiments comparing the new developed image processing technique with the standard microscopic counting technique.

  14. IMMUNE REGULATING ES-PRODUCTS IN PARASITIC NEMATODES

    DEFF Research Database (Denmark)

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

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

  15. Assessment of nematode community structure as a bioindicator in river monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H.C.; Chen, P.C. [Department of Plant Pathology, National Chung Hsing University, 250 Kuo Kuan Rd, Taichung 402, Taiwan (China); Tsay, T.T., E-mail: tttsay@nchu.edu.t [Department of Plant Pathology, National Chung Hsing University, 250 Kuo Kuan Rd, Taichung 402, Taiwan (China)

    2010-05-15

    Nematode communities from river water and sediments were assessed for the abundance, feeding types, maturity indices and nematode channel ratio (NCR). The sampling sites studied included different levels of pollution and contamination from agricultural, industrial and sewage sources. The nematode abundance found in the sediment samples was more than that in the water samples. The lowest nematode abundance in sediment samples and the lowest NCR in water samples were both found at the industrial pollution site. Water samples showed positive correlation between the NCR and river pollution index (RPI). Mean maturity indices in sediment samples were inversely correlated with RPI. The pollutant source determined the relationship between NCR and pollution level, while maturity index always showed negative correlation with pollutant level regardless of the pollutant sources. The nematode abundance and its community structure were both reliable bioindicators for monitoring long-term river pollution in both qualitative and quantitative aspects. - Nematode community structure in rivers is related to the contamination source and level.

  16. Assessment of nematode community structure as a bioindicator in river monitoring

    International Nuclear Information System (INIS)

    Wu, H.C.; Chen, P.C.; Tsay, T.T.

    2010-01-01

    Nematode communities from river water and sediments were assessed for the abundance, feeding types, maturity indices and nematode channel ratio (NCR). The sampling sites studied included different levels of pollution and contamination from agricultural, industrial and sewage sources. The nematode abundance found in the sediment samples was more than that in the water samples. The lowest nematode abundance in sediment samples and the lowest NCR in water samples were both found at the industrial pollution site. Water samples showed positive correlation between the NCR and river pollution index (RPI). Mean maturity indices in sediment samples were inversely correlated with RPI. The pollutant source determined the relationship between NCR and pollution level, while maturity index always showed negative correlation with pollutant level regardless of the pollutant sources. The nematode abundance and its community structure were both reliable bioindicators for monitoring long-term river pollution in both qualitative and quantitative aspects. - Nematode community structure in rivers is related to the contamination source and level.

  17. Molecular characterization of the Drosophila responses towards nematodes

    OpenAIRE

    Arefin, Md. Badrul

    2016-01-01

    A sophisticated evolutionary conserved innate immune system has evolved in insects to fight pathogens and to restrict damage in harmful (danger) situations including cancer. A significant amount of knowledge about different infection models in Drosophila has been generated in past decades, which revealed functional resemblances and implications for vertebrate systems. However, how Drosophila responds towards multicellular parasitic nematodes and in danger situations is still little understood...

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

    OpenAIRE

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

    2011-01-01

    Root-knot nematodes are biotrophic parasites that invade the root apex of host plants and migrate towards the vascular cylinder where they induce the differentiation of root cells into hypertrophied multinucleated giant cells. Giant cells are part of the permanent feeding site required for nematode development into the adult stage. To date, a repertoire of candidate effectors potentially secreted by the nematode into the plant tissues to promote infection has been identified. However, the pre...

  19. Prevalence and intensity of infection with gastrointestinal nematodes in sheep in eastern Serbia

    OpenAIRE

    Kulišić, Z.; Aleksić, Nevenka; Đorđević, M.; Gajić, B.; Tambur, Z.; Stevanović, Jevrosima; Stanimirović, Z.

    2013-01-01

    A coprological examination of 680 grazing sheep was performed in Eastern Serbia from March 2011 to November 2012 in order to determine the presence of gastrointestinal (GI) nematode parasites. Fecal samples were randomly collected and examined by using qualitative and quantitative coprological techniques. It was found that 74.56% sheep were infected. Samples that contained nematode eggs were processed for larval development and eleven nematode genera were i...

  20. Partitioning Yield Loss on Yellow Squash into Nematode and Insect Components

    OpenAIRE

    McSorley, R.; Waddill, V. H.

    1982-01-01

    The effect of a contplex of several insect and nematode pests on yield of yellow squash (Cucurbita pepo L.) was examined in two field tests in southern Florida. Applications of permethrin for insect control and oxamyl primarily for nematode control plus some insect control were made alone and in combination to achieve differential reduction of various insect and nematode components contributing to yield loss. The effect of these components on yield was further analyzed by multiple regression....

  1. Transcriptome Analysis of Resistant and Susceptible Alfalfa Cultivars Infected With Root-Knot Nematode Meloidogyne incognita

    OpenAIRE

    Postnikova, Olga A.; Hult, Maria; Shao, Jonathan; Skantar, Andrea; Nemchinov, Lev G.

    2015-01-01

    Nematodes are one of the major limiting factors in alfalfa production. Root-knot nematodes (RKN, Meloidogyne spp.) are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to alfalfa fields. As of today, no studies have been published on global gene expression profiling in alfalfa infected with RKN or any other plant parasitic nematode. Very little information is available about molecular mechanisms that contribute...

  2. A nematode that can manipulate the behaviour of slugs.

    Science.gov (United States)

    Morris, Alex; Green, Michael; Martin, Hayley; Crossland, Katie; Swaney, William T; Williamson, Sally M; Rae, Robbie

    2018-02-27

    The ability of parasites to manipulate the behaviour of their hosts has evolved multiple times, and has a clear fitness benefit to the parasite in terms of facilitating growth, reproduction and transfer to suitable hosts. The mechanisms by which these behavioural changes are induced are poorly understood, but in many cases parasite manipulation of serotonergic signalling in the host brain is implicated. Here we report that Phasmarhabditis hermaphrodita, a parasite of terrestrial gastropod molluscs, can alter the behaviour of slugs. Uninfected slugs (Deroceras panormitanum, Arion subfuscus and Arion hortensis) avoid areas where P. hermaphrodita is present, but slugs infected with P. hermaphrodita are more likely to be found where the nematodes are present. This ability is specific to P. hermaphrodita and other nematodes (Steinernema carpocapsae and Heterorhabditis bacteriophora) do not induce this behavioural change. To investigate how P. hermaphrodita changes slug behaviour we exposed slugs to fluoxetine (a selective serotonin reuptake inhibitor) and cyproheptadine (a serotonin receptor antagonist). Uninfected slugs fed fluoxetine no longer avoided areas where P. hermaphrodita was present; and conversely, infected slugs fed cyproheptadine showed no increased attraction to areas with nematodes. These findings suggest that a possible mechanism by whichP. hermaphrodita is able to manipulate parasite avoidance behaviour in host slugs is by manipulating serotonergic signalling in the brain, and that increased serotonin levels are potentially associated with a reduction in parasite avoidance. Copyright © 2018. Published by Elsevier B.V.

  3. Origanum vulgare (Lamiaceae OVICIDAL POTENTIAL ON GASTROINTESTINAL NEMATODES OF CATTLE

    Directory of Open Access Journals (Sweden)

    Luciana Laitano Dias de Castro

    2013-12-01

    Full Text Available Due to anthelmintic resistance in nematodes, several research studies have been developed seeking control alternatives to these parasites. This study evaluated the in vitro action of Origanum vulgare on gastrointestinal nematode eggs of cattle. In order to evaluate the ability to inhibit egg hatch, different dried leaves extracts of this plant were tested, such as dye, hydroalcoholic and aqueous extracts at concentrations varying from 0.62 to 80 mg/mL. Each assay was accompanied by control containing levamisole hydrochloride (0.2 mg/mL, distilled water and 70 ºGL grain alcohol at the same concentration of the extracts. Test results showed that the different O. vulgare extracts inhibited egg hatch of cattle gastrointestinal nematodes at a percentage that varied from 8.8 to 100%; dye and hydroalcoholic extract were the most promising inhibitors. In view of this ovicidal property, O. vulgare may be an important source of viable antiparasitic compounds for nematodiosis control in ruminants.

  4. Scaleable downstream recovery of nematodes used as biopesticides.

    Science.gov (United States)

    Wilson, J A; Pearce, J D; Ayazi Shamlou, P

    2001-12-20

    This study assesses the suitability of sieving as a scaleable technique for the separation of adult nematodes from infective juveniles, the latter is an effective bioinsecticide whereas the former is waste material resulting from the fermentation process. Batch and semibatch experiments using conventional flow-assisted wet sieving and a novel cross-flow sieving technique were used to study the separation of juveniles from adult nematodes. The experiments were carried out using small-scale devices and the data were analyzed in terms of the screen effectiveness factor. The results were used to identify the sieve size and operating conditions for optimum juvenile recovery. It was found that, for a given species of nematode, optimum recovery was achieved when sieving was carried out in the cross-flow mode, the maximum recovery being a function of the size of the screen. Industrial-scale self-cleaning equipment capable of large-scale continuous screening was used to confirm the capacity of the small-scale operation for scale-up. Experimental results with this unit showed that in continuous operation sieving time is an additional parameter that influences separation performance. Copyright 2001 John Wiley & Sons, Inc.

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

    Science.gov (United States)

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

    2016-01-01

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

  6. The importance, biology and management of cereal cyst nematodes (Heterodera spp.

    Directory of Open Access Journals (Sweden)

    F. Mokrini

    2018-01-01

    Full Text Available Cereals are exposed to biotic and abiotic stresses. Among the biotic stresses, plant-parasitic nematodes play an important role in decreasing crop yield. Cereal cyst nematodes (CCNs are known to be a major constraint to wheat production in several parts of the world. Significant economic losses due to CCNs have been reported. Recognition and identification of CCNs are the first steps in nematode management. This paper reviews the current distribution of CCNs in different parts of the world and the recent advances in nematode identification. The different approaches for managing CCNs are also discussed.

  7. Nematodes as a source of total coliforms in a distribution system.

    Science.gov (United States)

    Locas, Annie; Barbeau, Benoit; Gauthier, Vincent

    2007-05-01

    In a distribution system of a large North American city, recurring total coliforms and atypical coliforms were detected at the exit (distribution pumps) of a storage reservoir. The presence of total coliforms and atypical coliforms was noted when the pumps were in operation and the water temperature was higher than 18 degrees C. The total coliform and atypical coliform concentrations at the volute pump casings ranged from 0 to 93.5 colony forming units (cfu)/100 mL. Significant concentrations of nematodes were also detected at this sampling location, averaging 12.0 nematodes/L in 2001 and 17.4 nematodes/L in 2002. The hypothesis that coliforms were released from the nematodes during their transit through the high-pressure pump was tested by recovering nematodes by filtering large volumes of water and grinding the nematodes in the laboratory, using various techniques. Total coliform and heterotrophic bacteria concentrations ranged from 0 to 27 cfu/nematode and 0 to 643 cfu/nematode, respectively. The origin of the nematodes was traced back to the sand filters located at the two water treatment plants. The importance of invertebrates in the distribution system should not be dismissed and the associated health risks, if any, should be assessed.

  8. Rhizome extracts of Curcuma zedoaria Rosc induce caspase dependant apoptosis via generation of reactive oxygen species in filarial parasite Setaria digitata in vitro.

    Science.gov (United States)

    Senathilake, K S; Karunanayake, E H; Samarakoon, S R; Tennekoon, K H; de Silva, E D

    2016-08-01

    Human lymphatic filariasis (LF) is mainly caused by filarial parasite Wuchereria bancrofti and is the second leading cause of long term and permanent disability in tropical countries. To date, incapability to eliminate long lived adult parasites by current drugs remains the major challenge in the elimination of LF. Hence, in the current study, the efficacy of rhizome extracts of Curcuma zedoaria (a plant traditionally used in Sri Lanka in the management of LF) was evaluated as an effective filaricide in vitro. Sequential solvent extracts of C. zedoaria rhizomes were screened for in vitro antifilarial activity at 0.01-1 mg/mL concentrations by motility inhibition assay and 3-(4, 5 dimethylthiazol-2-yl)-2, 5 diphenyl tetrazolium bromide (MTT) reduction assay using cattle parasite Setaria digitata as a model organism. Exposure of parasites to hexane and chloroform extracts of C. zedoaria caused a dose dependant reduction in motility and viability of microfilariae (IC50 = 72.42 μg/mL for hexane extract, 191.14 μg/mL for chloroform extract) and adult parasites (IC50 = 77.07 μg/mL for hexane extract, 259.87 μg/mL for chloroform extract). Both extracts were less toxic to human peripheral blood mononuclear cells when compared to filariae. A dose dependant increase in caspase 3/CED 3 and a decrease in total protein content, cyclooxygenase (COX) and protein tyrosine phosphatase (PTP) activities were observed in adult parasites treated with hexane or chloroform extract. A significant degree of chromatin condensation and apoptotic body formation were also observed in these worms by Hoechst 33342 and terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling (TUNEL) staining respectively. Dose dependant chromosomal DNA laddering was observed in treated adult worms but not in microfilariae in response to both extracts. Oxidative stress parameters such as reduction in reduced glutathione (GSH) levels and increase in glutathione s transferase (GST

  9. Soil nematode assemblages as bioindicators of radiation impact in the Chernobyl Exclusion Zone

    Energy Technology Data Exchange (ETDEWEB)

    Lecomte-Pradines, C., E-mail: catherine.lecomte-pradines@irsn.fr [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LECO, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Bonzom, J.-M. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LECO, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Della-Vedova, C. [Magelis, 6, rue Frederic Mistral, 84160 Cadenet (France); Beaugelin-Seiller, K. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LM2E, Building 159, Cadarache 13115 Saint Paul lez Durance cedex (France); Villenave, C. [ELISOL Environment, Building 12, Campus de la Gaillarde, 2 place Viala, 34060 Montpellier cedex 2 (France); Gaschak, S. [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); Coppin, F. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, L2BT, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Dubourg, N. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, GARM Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Maksimenko, A. [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); Adam-Guillermin, C. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LECO, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Garnier-Laplace, J. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, Building 159, Cadarache 13115 Saint Paul lez Durance cedex (France)

    2014-08-15

    In radioecology, the need to understand the long-term ecological effects of radioactive contamination has been emphasised. This requires that the health of field populations is evaluated and linked to an accurate estimate of received radiological dose. The aim of the present study was to assess the effects of current radioactive contamination on nematode assemblages at sites affected by the fallout from the Chernobyl accident. First, we estimated the total dose rates (TDRs) absorbed by nematodes, from measured current soil activity concentrations, Dose Conversion Coefficients (DCCs, calculated using EDEN software) and soil-to-biota concentration ratios (from the ERICA tool database). The impact of current TDRs on nematode assemblages was then evaluated. Nematodes were collected in spring 2011 from 18 forest sites in the Chernobyl Exclusion Zone (CEZ) with external gamma dose rates, measured using radiophotoluminescent dosimeters, varying from 0.2 to 22 μGy h{sup −1}. These values were one order of magnitude below the TDRs. A majority of bacterial-, plant-, and fungal-feeding nematodes and very few of the disturbance sensitive families were identified. No statistically significant association was observed between TDR values and nematode total abundance or the Shannon diversity index (H′). The Nematode Channel Ratio (which defines the relative abundance of bacterial- versus fungal-feeding nematodes) decreased significantly with increasing TDR, suggesting that radioactive contamination may influence nematode assemblages either directly or indirectly by modifying their food resources. A greater Maturity Index (MI), usually characterising better soil quality, was associated with higher pH and TDR values. These results suggest that in the CEZ, nematode assemblages from the forest sites were slightly impacted by chronic exposure at a predicted TDR of 200 μGy h{sup −1}. This may be imputable to a dominant proportion of pollutant resistant nematodes in all sites

  10. Sensory interaction between attractant diacetyl and repellent 2-nonanone in the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Matsuura, Tetsuya; Izumi, Junichi; Hioki, Mamoru; Nagaya, Hiroki; Kobayashi, Yasuaki

    2013-06-01

    In the nematode Caenorhabditis elegans, the odorant diacetyl is sensed by AWA sensory neurons in the amphid sensory organ and elicits an attractive response, whereas 2-nonanone is sensed by AWB amphid sensory neurons and elicits an avoidance response. In the present study, we report that nematodes exhibit a sensory interaction between the attractant diacetyl and repellent 2-nonanone. In the presence of food, the chemotactic response to 0.01% diacetyl in nematodes preexposed to 0.1% diacetyl was greater than that in nonexposed naive nematodes (P < 0.05). The response to diacetyl was also greater in nematodes preexposed to 3% 2-nonanone in the presence of food than that in naive nematodes (P < 0.01). In the absence of food, the response to diacetyl in nematodes preexposed to diacetyl or 2-nonanone was significantly lower than that in nonexposed control nematodes (P < 0.01). The avoidance response to 10% 2-nonanone in nematodes preexposed to each odorant in the presence or absence of food was lower than that in nonexposed nematodes (P < 0.05). To confirm the validity of our results, the chemotactic responses to diacetyl and 2-nonanone were observed using che-3, odr-4, and odr-10 mutants, which exhibited defective sensitivity to diacetyl or 2-nonanone. From the results of our experiments, we conclude that nematodes exhibit a sensory interaction between diacetyl and 2-nonanone and speculate that this interaction is driven by higher-level neuronal circuits that underlie sensory integration. Copyright © 2013 Wiley Periodicals, Inc.

  11. Soil nematode assemblages as bioindicators of radiation impact in the Chernobyl Exclusion Zone.

    Science.gov (United States)

    Lecomte-Pradines, C; Bonzom, J-M; Della-Vedova, C; Beaugelin-Seiller, K; Villenave, C; Gaschak, S; Coppin, F; Dubourg, N; Maksimenko, A; Adam-Guillermin, C; Garnier-Laplace, J

    2014-08-15

    In radioecology, the need to understand the long-term ecological effects of radioactive contamination has been emphasised. This requires that the health of field populations is evaluated and linked to an accurate estimate of received radiological dose. The aim of the present study was to assess the effects of current radioactive contamination on nematode assemblages at sites affected by the fallout from the Chernobyl accident. First, we estimated the total dose rates (TDRs) absorbed by nematodes, from measured current soil activity concentrations, Dose Conversion Coefficients (DCCs, calculated using EDEN software) and soil-to-biota concentration ratios (from the ERICA tool database). The impact of current TDRs on nematode assemblages was then evaluated. Nematodes were collected in spring 2011 from 18 forest sites in the Chernobyl Exclusion Zone (CEZ) with external gamma dose rates, measured using radiophotoluminescent dosimeters, varying from 0.2 to 22 μGy h(-1). These values were one order of magnitude below the TDRs. A majority of bacterial-, plant-, and fungal-feeding nematodes and very few of the disturbance sensitive families were identified. No statistically significant association was observed between TDR values and nematode total abundance or the Shannon diversity index (H'). The Nematode Channel Ratio (which defines the relative abundance of bacterial- versus fungal-feeding nematodes) decreased significantly with increasing TDR, suggesting that radioactive contamination may influence nematode assemblages either directly or indirectly by modifying their food resources. A greater Maturity Index (MI), usually characterising better soil quality, was associated with higher pH and TDR values. These results suggest that in the CEZ, nematode assemblages from the forest sites were slightly impacted by chronic exposure at a predicted TDR of 200 μGy h(-1). This may be imputable to a dominant proportion of pollutant resistant nematodes in all sites. This might

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  13. Soil and freshwater nematodes of the Iberian fauna: A synthesis

    Directory of Open Access Journals (Sweden)

    Peña-Santiago, R.

    2006-12-01

    Full Text Available The first available compilation of Iberian soil and freshwater nematodes is presented in this paper. The inventory is currently made up of 981 species belonging to 236 genera, 77 families and 12 orders. Data of the Iberian nematode fauna are compared with other components of the Iberian biota, as well as the nematode fauna of other geographical regions. Quantitative and qualitative aspects of the nematode inventory are analyzed and discussed, paying special attention to the kind of information available for each species, and concluding that practically one-third of Iberian species are deficiently characterized and need further study. Endemicity of Iberian species is also considered: 143 species, 14.6% of the total, are restricted (in their distribution to the Iberian geography, most of them being members of the orders Dorylaimida (87 and Tylenchida (29, which are also the most diversified nematode taxa. Practical or applied interest of knowledge of the Iberian nematode fauna is commented and supported with examples and recent contributions. Finally, an alphabetical list of the species, ordered by specific name, is provided.

    En esta contribución se presenta una recopilación de las especies ibéricas de nematodos de suelo y de agua dulce, la primera de este tipo realizada hasta el momento. El inventario actual lo componen 981 especies de 236 géneros, 77 familias y 12 órdenes. Los datos correspondiente a la fauna ibérica de nematodos se compara con la de otros táxones de la biota ibérica. Se analizan y se discuten distintos aspectos cuantitativos y cualitativos de la fauna nematológica, con especial énfasis en el tipo de información disponible sobre cada especie, y se concluye que casi una tercera parte de las especies ibéricas permanecen insuficientemente caracterizadas, razón por la cual requieren de estudios adicionales. La endemicidad de las especies es así mismo objeto de atención: 143 especies, un 14.6% del total est

  14. Soil nematodes show a mid-elevation diversity maximum and elevational zonation on Mt. Norikura, Japan.

    Science.gov (United States)

    Dong, Ke; Moroenyane, Itumeleng; Tripathi, Binu; Kerfahi, Dorsaf; Takahashi, Koichi; Yamamoto, Naomichi; An, Choa; Cho, Hyunjun; Adams, Jonathan

    2017-06-08

    Little is known about how nematode ecology differs across elevational gradients. We investigated the soil nematode community along a ~2,200 m elevational range on Mt. Norikura, Japan, by sequencing the 18S rRNA gene. As with many other groups of organisms, nematode diversity showed a high correlation with elevation, and a maximum in mid-elevations. While elevation itself, in the context of the mid domain effect, could predict the observed unimodal pattern of soil nematode communities along the elevational gradient, mean annual temperature and soil total nitrogen concentration were the best predictors of diversity. We also found nematode community composition showed strong elevational zonation, indicating that a high degree of ecological specialization that may exist in nematodes in relation to elevation-related environmental gradients and certain nematode OTUs had ranges extending across all elevations, and these generalized OTUs made up a greater proportion of the community at high elevations - such that high elevation nematode OTUs had broader elevational ranges on average, providing an example consistent to Rapoport's elevational hypothesis. This study reveals the potential for using sequencing methods to investigate elevational gradients of small soil organisms, providing a method for rapid investigation of patterns without specialized knowledge in taxonomic identification.

  15. Product evaluation for reniform nematode suppression in Mississippi Delta sweetpotato production, 2011

    Science.gov (United States)

    The reniform nematode, Rotylenchulus reniformis, can cause significant losses in sweetpotato, Ipomoea batatas, production in the Mississippi Delta. Reniform nematode is a microscopic plant parasite that feeds on sweetpotato roots causing severe stunting of root growth. Reduction in yield due to the ...

  16. Genomic characterisation of the effector complement of the potato cyst nematode Globodera pallida

    NARCIS (Netherlands)

    Thorpe, P.; Mantelin, S.; Cock, P.J.A.; Blok, V.C.; Coke, M.C.; Evers-van den Akker, S.; Guzeeva, E.; Lilley, C.J.; Smant, G.; Reid, A.J.; Wright, K.M.; Urwin, P.E.; Jones, J.T.

    2014-01-01

    Background The potato cyst nematode Globodera pallida has biotrophic interactions with its host. The nematode induces a feeding structure – the syncytium – which it keeps alive for the duration of the life cycle and on which it depends for all nutrients required to develop to the adult stage.

  17. Azadirachtin powder for control of root-knot nematodes in tomato

    Science.gov (United States)

    USDA ARS Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center, 64 Nowelo St., Hilo, HI 96720. Root-knot nematodes cause root galling and yield reductions in many vegetable crops, including tomato. Three organic treatments to improve root growth and reduce nematode infestation were eval...

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  19. Sunn Hemp cover cropping and organic fertilizer effects on the nematode community under temperate growing conditions

    Science.gov (United States)

    Plantings of sunn hemp as a cover crop have been experimentally shown to improve soil health, reduce plant-parasitic nematodes, and increase nematode-antagonistic microorganisms. However, these studies have been largely conducted in tropical and subtropical regions. To investigate the impacts of sun...

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

    Science.gov (United States)

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

    2006-01-01

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

  1. NEMATODE DIVERSITY IN A RANGE OF LAND USE TYPES IN JAMBI BENCHMARK INDONESIA

    Directory of Open Access Journals (Sweden)

    I Gede Swibawa & Titik Nur Aeny .

    2011-11-01

    Full Text Available Nematode Diversity in a Range of Land Use Types in Jambi Benchmark Indonesia. This study was conducted in Jambi  Benchmark, Indonesia from May 2004 to March 2005.  Out of 70 sampling points, 35 soil cores were taken from five land use types including forest less intensive, forest intensive, shrub, tree-based intensive, and crop-based less intensive.  From each soil core, 300 ml of soil was extracted by flotation and centrifugation technique using sucrose solution. One hundred randomly picked nematodes from each sample were identified to  genus level. The collected data were nematode abundance, number of genera, and trophic groups. The results showed that a total of 100 nematode genera within 31 families and 8 orders were found from soil samples of Jambi Benchmark. The abundance of total nematodes, bacterial feeding, and plant feeding nematodes were low in the intensive land use but high in less intensive land uses, i.e. shrub, intensive forest, and less intensive forest.  There was no significant correlation between land use intensity and the diversity of nematode taxa.  Nematode maturity indices were not sensitive enough to measure ecosystem disturbance caused by human intervention in Jambi Benchmark.

  2. RNAseq Analysis of the Drosophila Response to the Entomopathogenic Nematode Steinernema

    Directory of Open Access Journals (Sweden)

    Shruti Yadav

    2017-06-01

    Full Text Available Drosophila melanogaster is an outstanding model to study the molecular and functional basis of host–pathogen interactions. Currently, our knowledge of microbial infections in D. melanogaster is well understood; however, the response of flies to nematode infections is still in its infancy. Here, we have used the potent parasitic nematode Steinernema carpocapsae, which lives in mutualism with its endosymbiotic bacteria Xenorhabdus nematophila, to examine the transcriptomic basis of the interaction between D. melanogaster and entomopathogenic nematodes. We have employed next-generation RNA sequencing (RNAseq to investigate the transcriptomic profile of D. melanogaster larvae in response to infection by S. carpocapsae symbiotic (carrying X. nematophila or axenic (lacking X. nematophila nematodes. Bioinformatic analyses have identified the strong induction of genes that are associated with the peritrophic membrane and the stress response, as well as several genes that participate in developmental processes. We have also found that genes with different biological functions are enriched in D. melanogaster larvae responding to either symbiotic or axenic nematodes. We further show that while symbiotic nematode infection enriched certain known immune-related genes, axenic nematode infection enriched several genes associated with chitin binding, lipid metabolic functions, and neuroactive ligand receptors. In addition, we have identified genes with a potential role in nematode recognition and genes with potential antinematode activity. Findings from this study will undoubtedly set the stage for the identification of key regulators of antinematode immune mechanisms in D. melanogaster, as well as in other insects of socioeconomic importance.

  3. Optimization of a host diet for in vivo production of entomopathogenic nematodes

    Science.gov (United States)

    In previous studies, we developed an improved diet for Tenebrio molitor, a host that is used for in vivo nematode production, and we demonstrated that single insect diet components (e.g., lipids and proteins) can have a positive or negative impact on entomopathogenic nematode fitness and quality. I...

  4. Low cost production of nematodes for biological control of insect pests

    Science.gov (United States)

    Entomopathogenic nematodes are produced in two ways: in artificial media using liquid or solid fermentation methods (in vitro) or by mass producing insect hosts to be artificially exposed to mass infection by nematodes (in vivo). The yellow mealworm (Tenebrio molitor) is a good host for in vivo nema...

  5. Two simple methods for the collection of individual life stages of reniform nematode, Rotylenchulus reniformis

    Science.gov (United States)

    The sedentary semi-endoparasitic nematode Rotylenchulus reniformis, the reniform nematode, is a serious pest of cotton and soybean in the United States. In recent years, interest in the molecular biology of the interaction between R. reniformis and its plant hosts has increased; however, the unusual...

  6. Controlling Aphelenchoides subtenuis nematodes with a hot water treatment in Crocus and Allium

    NARCIS (Netherlands)

    Leeuwen, van P.J.; Trompert, J.P.T.

    2011-01-01

    Several bulbous crops like Crocus, Allium and some species of Tulipa and Narcissus can be infected with the nematode Aphelenchoides subtenuis. The nematodes cause retarded growth, poor or no flowering and eventually death of the bulbs and corms. A hot water treatment after lifting the bulbs has

  7. Evaluation of tomato genotypes for resistance to root-knot nematodes

    African Journals Online (AJOL)

    Tomato (Solanum lycopersicum) is one of the most popular vegetable crops worldwide, owing to its high nutritive value and diversified use. Tomato production in Ghana is threatened by plant parasitic nematodes, especially the root knot nematodes (Meloidogyne spp.), which are responsible for huge economic yield losses.

  8. Mind the gaps in research on the control of gastrointestinal nematodes of farmed ruminants and pigs

    DEFF Research Database (Denmark)

    Charlier, J; Thamsborg, S M; Bartley, D J

    2018-01-01

    Gastrointestinal (GI) nematode control has an important role to play in increasing livestock production from a limited natural resource base and to improve animal health and welfare. In this synthetic review, we identify key research priorities for GI nematode control in farmed ruminants and pigs...

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

    NARCIS (Netherlands)

    Smant, Geert; Helder, Johannes; Goverse, Aska

    2018-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Sagar Banerjee

    2017-05-01

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

  11. HOW FUNGI INTERACT WITH NEMATODE TO ACTIVATE THE PLANT DEFENCE RESPONSE TO TOMATO PLANTS.

    Science.gov (United States)

    Leonetti, P; Costanza, A; Zonno, M C; Molinari, S; Altomare, C

    2014-01-01

    Management of plant parasitic nematodes with nematode predators, parasites or antagonists is an eco-friendly approach that may avoid the problems arisen by the use of toxic chemicals. Fungi belonging to Trichoderma spp. are well known in literature for their role in control of plant parasitic nematodes. Root-knot nematodes (RKNs), Meloidogyne spp., are obligate parasites that cause the formation of familiar galls on the roots of many cultivated plants. The interaction between the M. incognita motile second stage juveniles (J2s) and the isolate ITEM 908 of Trichoderma harzianum was examined in its effect on the nematode infestation level of susceptible tomato plants. To gain insight into the mechanisms by which ITEM 908 interacts with nematode-infected tomato plants, the expression patterns of the genes PR1 (marker of Salycilic Acid-depending resistance signalling pathway) and JERF3 (marker of the Jasmonic Acid/Ethylene-depending resistance signalling pathway) were detected over time in: i) untreated roots; ii) roots pre-treated with the fungus; iii) roots inoculated with the nematode; iv) pre-treated and inoculated roots. Infestation parameters were checked in untreated plants and plants treated with the fungus to test the effect of the fungus on nematode infestation level and to compare this effect with the expression of the genes PR1 and JERF3, involved in induced resistance.

  12. Controlling tulip stem nematodes in tulip bulbs by a hot water treatment

    NARCIS (Netherlands)

    Dam, van M.F.N.

    2013-01-01

    A hot water treatment (HWT) protocol is needed to control tulip stem nematode (TSN) in tulip bulbs. A HWT above approximately 45°C in tulips is assumed to be harmful to the bulbs. Experience with HWT to destroy stem nematodes in daffodils shows that the required temperature for this is 4 hours at

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

    NARCIS (Netherlands)

    Goverse, A.; Smant, G.

    2014-01-01

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

  14. Heterodera schachtii Tyrosinase-like protein a novel nematode effector modulating plant hormone homeostasis

    Czech Academy of Sciences Publication Activity Database

    Habash, S.; Radakovic, Z.S.; Vaňková, Radomíra; Siddique, S.; Dobrev, Petre; Gleason, C.; Grundler, F.M.W.; Elashry, A.

    2017-01-01

    Roč. 7, JUL 31 (2017), č. článku 6874. ISSN 2045-2322 Institutional support: RVO:61389030 Keywords : arabidopsis-thaliana * cyst-nematode * parasitic nematode * transient expression * host plants * sequence * identification * infection * model * transformation Subject RIV: ED - Physiology OBOR OECD: Plant sciences, botany Impact factor: 4.259, year: 2016

  15. Molecular contest between potato and the potato cyst nematode Globodera pallida: modulation of Gpa2-mediated resistance

    NARCIS (Netherlands)

    Koropacka, K.B.

    2010-01-01

    Gpa2 recognition specificity
    Among all the multicellular animals, nematodes are the most numerous. In soil, a high variety
    of free living nematodes feeding on bacteria can be found as well as species that parasitize
    insects, animals or plants. The potato cyst nematode (PCN)

  16. Anthelmintic activity of Cocos nucifera L. against sheep gastrointestinal nematodes.

    Science.gov (United States)

    Oliveira, L M B; Bevilaqua, C M L; Costa, C T C; Macedo, I T F; Barros, R S; Rodrigues, A C M; Camurça-Vasconcelos, A L F; Morais, S M; Lima, Y C; Vieira, L S; Navarro, A M C

    2009-01-22

    The development of anthelmintic resistance has made the search for alternatives to control gastrointestinal nematodes of small ruminants imperative. Among these alternatives are several medicinal plants traditionally used as anthelmintics. This work evaluated the efficacy of Cocos nucifera fruit on sheep gastrointestinal parasites. The ethyl acetate extract obtained from the liquid of green coconut husk fiber (LGCHF) was submitted to in vitro and in vivo tests. The in vitro assay was based on egg hatching (EHT) and larval development tests (LDT) with Haemonchus contortus. The concentrations tested in the EHT were 0.31, 0.62, 1.25, 2.5 and 5 mg ml(-1), while in the LDT they were 5, 10, 20, 40 and 80 mg ml(-1). The in vivo assay was a controlled test. In this experiment, 18 sheep infected with gastrointestinal nematodes were divided into three groups (n=6), with the following doses administered: G1-400 mg kg(-1) LGCHF ethyl acetate extract, G2-0.2 mg kg(-1) moxidectin (Cydectin) and G3-3% DMSO. The worm burden was analyzed. The results of the in vitro and in vivo tests were submitted to ANOVA and analyzed by the Tukey and Kruskal-Wallis tests, respectively. The extract efficacy in the EHT and LDT, at the highest concentrations tested, was 100% on egg hatching and 99.77% on larval development. The parameters evaluated in the controlled test were not statistically different, showing that despite the significant results of the in vitro tests, the LGCHF ethyl acetate extract showed no activity against sheep gastrointestinal nematodes.

  17. Controlling gastrointestinal nematodes in cattle by Bacillus species.

    Science.gov (United States)

    Pinto, Natália Berne; de Castro, Leonardo Mortagua; de Almeida Capella, Gabriela; Motta, Tairan Ourique; de Souza Stori de Lara, Ana Paula; de Moura, Micaele Quintana; Berne, Maria Elisabeth Aires; Leite, Fábio Pereira Leivas

    2017-10-15

    In this study, we tested the in vitro and in vivo larvicidal activity of Bacillus species against gastrointestinal nematodes in cattle, and their viability in the presence of anthelmintics. For in vitro tests, cattle feces naturally infected with trichostrongylides were incubated with spore suspensions of Bacillus circulans (Bcir), B. thuringiensis var. osvaldocruzi (Bto), B. thuringiensis var. israelensis (Bti) or B. thuringiensis var. kurstaki (Btk). Subsequently, residual larvae were counted and identified. All of the Bacillus species showed 60% or more larvicidal effects. Bcir and Bti were selected to be incubated with anthelmintics (moxidectin, nitroxynil and levamisole), and after 24, 72, and 144h, their viability was evaluated. Bti showed highest drug resistance, maintaining a concentration of 1×10 7 CFU/mL. Based on this result, Bti was selected for in vivo tests on calves naturally infected with gastrointestinal nematodes. The calves were dived into four groups: Group 1, Bti suspension of ∼1×10 9 CFU orally administered; Group 2, Bti suspension of ∼1×10 9 CFU orally administered with levamisole (subcutaneously, 150mg); Group 3, only levamisole (subcutaneously, 150mg), and Group 4 untreated. Then 24 and 48h after treatment, larvae numbers were counted. We observed a reduction of 84%, 100%, and 100% after 48h of treatment, respectively, for Groups 1, 2 and 3 treatments in comparison with the untreated. The tested Bacillus species showed larvicidal activity against bovine trichostrongylides, and its association with anthelmintics. It may serve as a promising integrated alternative for control of gastrointestinal nematodes in cattle. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2008-12-09

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

  19. Cadmium toxicity in the free-living nematode, Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Popham, J.D.; Webster, J.M.

    1979-10-01

    The effect of cadmium on the fecundity, growth, and fine structure of the free-living nematode Caenorhabditis elegans was studied. High concentrations of cadmium significantly decreased the fecundity and growth of these organisms. Electron microscopy showed that cadmium modifies the structure of the mitochondria in the esophagus and intestine, causes the formation of inclusion bodies in the nucleus of esophageal cells, and alters the morphology of cytosomes in the intestinal cells. The results suggest that the decreased fecundity and growth of cadmium-exposed C. elegans may be due to cadmium interfering with nutrient uptake or assimilation or both.

  20. Evaluation the effect of albendazole against nematodes in sheep

    Directory of Open Access Journals (Sweden)

    M. I. Al-Farwachi

    2008-01-01

    Full Text Available Six sheep farms in Mosul city, Iraq randomly selected, were surveyed for gastrointestinal nematodes resistant to Albendazole. On each of 6 sheep farms, 20 lambs were randomly distributed into two equal groups untreated control group, and albendazole (benzimidazole group (10 mg/kg BW. Faecal egg counts and larval cultures were done at 7, 14, and 21 days after anthelmintic treatment. Resistance was apparent for albendazole on 4 farms out of 6 (66.7%. Post-treatment larval cultures indicated: Strongyloides papillosus, Marshalligia marshalli, Nematodirus spathiger and Haemonchus contortus.

  1. Anthelmintic resistance in cattle nematodes in the US.

    Science.gov (United States)

    Gasbarre, Louis C

    2014-07-30

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

  2. Role of nematodes as bioindicators in marine and freshwater habitats

    Digital Repository Service at National Institute of Oceanography (India)

    Geetanjali; Malhotra, S.K.; Ansari, Z.A.; Chatterji, A.

    of frequency is less than 6000 Hz. These differences may be con - si dered as an indication of geographical variations and the possibility of the existence of a species complex. 1. Daniels, R. J. R., Cobra , 2001, 46 , in press. 2.../l and acidity, 3.5 ? 8.0 mg/l). On the con trary, in the nematode species infested M. tengra in river Ganges Sali - nity, 6.54 ppt; hardness, 115 ? 130 mg/l; DO, 7.4 ? 8.0 mg/l; phosphates 9 , 0.25 ? 0.65 mg/l; nitrates, < 50.0 mg/l; nitrit es...

  3. Treatment of Nematodes with Ozone Gas: A Sustainable Alternative to Nematicides

    Science.gov (United States)

    Msayleb, Nahed; Ibrahim, Saiid

    This study tests Ozone as a Nematicides' alternative. Nematode-infected soil samples were treated with ascending doses of O3 by submerging the outlet of an "MB1000 Ozone Generator" in the 40 ml samples; then to test the O3 nematicidal effect by gas fumigation, Ozone gas was released into a sealed bag containing 80 g of each of the 6 nematode-infected soil samples with ascending doses and a repetition of each. With water-ozonation, 900 mg O3 were needed to kill 100% of nematodes, and the O3-Nematodes LD50 was identified by 420 mg. With the second experiment, O3 soil fumigation for 50 minutes at a dose of 1,125 mg in an air volume of 5 litres, were needed to control 95% of living nematodes.

  4. The impact of whale falls on nematode abundance in the deep sea

    Science.gov (United States)

    Debenham, Nicola J.; Lambshead, P. John D.; Ferrero, Timothy J.; Smith, Craig R.

    2004-05-01

    Abundance of nematode assemblages from the sediment surrounding an experimentally implanted whale carcass in the Santa Cruz Basin were investigated at 1.5 and 18 months after placement. Samples were taken at 0, 1, 3, 9 and 30 m distance away from the carcass. Abundance is positively correlated with distance from the carcass out to at least 30 m. Analyses of nematode abundance at 18 months after implantation showed a non-linear inverse pattern to that of the macrofauna implying that enhanced macrofaunal activity immediately around the carcass was decreasing nematode abundance through predation or competition. The increased nematode abundance at 30 m after 18 months may be a response to organic enrichment from the whale fall occurring where macrofaunal abundance no longer limits nematode densities.

  5. THE PREVALENCE OF GASTROINTESTINAL NEMATODES OF BALI CATTLE BREEDERS IN NUSA PENIDA

    Directory of Open Access Journals (Sweden)

    Putu Agus Trisna Kusuma Antara

    2017-08-01

    Full Text Available Nusa Penida is a pure breeding area of bali cattle, in which the cattle are mainly kept in conventional maintenance system and potentially infected by parasite, especially gastrointestinal nematodes. This study aims were to determine the prevalence and type of gastrointestinal nematodes in bali cattle breeders in Nusa Penida. Fecal samples were taken from 50 bali cattle breeders kept in cages (simantri and another 50 samples were from cattle not kept in cage. The floating method was used for morphological examination and prevalence, the data was analyzed with descriptive analysis. The results showed, the prevalence of bovine gastrointestinal nematodes in Nusa Penida was 25%. The prevalence of nematode infection in bali cattle that kept cages was lower compared to the cattle that were not kept in cage. Strongyloides papillosus and Capillaria bovis were the gastrointestinal nematodes found in the infected cattle.

  6. Evidence for Wolbachia symbiosis in microfilariae of Wuchereria ...

    Indian Academy of Sciences (India)

    Wolbachia are symbiotic endobacteria that infect the majority of filarial nematodes, including Wuchereria bancrofti, Brugia malayi and Onchocerca volvulus. Recent studies have suggested that Wolbachia are necessary for the reproduction and survival of filarial nematodes and have highlighted the use of antibiotic therapy ...

  7. Disruption of prefoldin-2 protein synthesis in root-knot nematodes via host-mediated gene silencing efficiently reduces nematode numbers and thus protects plants.

    Science.gov (United States)

    Ajjappala, Hemavathi; Chung, Ha Young; Sim, Joon-Soo; Choi, Inchan; Hahn, Bum-Soo

    2015-03-01

    The aim of this study is to demonstrate the feasibility of down-regulating endogeneous prefoldin-2 root-knot nematode transcripts by expressing dsRNA with sequence identity to the nematode gene in tobacco roots under the influence of strong Arabidopsis ubiquitin (UBQ1) promoter. Root-knot nematodes (RKNs) are sedentary endoparasites infecting a wide range of plant species. They parasitise the root system, thereby disrupting water and nutrient uptake and causing major reductions in crop yields. The most reliable means of controlling RKNs is via the use of soil fumigants such as methyl bromide. With the emergence of RNA interference (RNAi) technology, which permits host-mediated nematode gene silencing, a new strategy to control plant pathogens has become available. In the present study, we investigated host-induced RNAi gene silencing of prefoldin-2 in transgenic Nicotiana benthamiana. Reductions in prefoldin-2 mRNA transcript levels were observed when nematodes were soaked in a dsRNA solution in vitro. Furthermore, nematode reproduction was suppressed in RNAi transgenic lines, as evident by reductions in the numbers of root knots (by 34-60 % in independent RNAi lines) and egg masses (by 33-58 %). Endogenous expression of prefoldin-2, analysed via real-time polymerase chain reaction and Western blotting, revealed that the gene was strongly expressed in the pre-parasitic J2 stage. Our observations demonstrate the relevance and potential importance of targeting the prefoldin gene during the nematode life cycle. The work also suggests that further improvements in silencing efficiency in economically important crops can be accomplished using RNAi directed against plant-parasitic nematodes.

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

    Directory of Open Access Journals (Sweden)

    Said K. Ibrahim

    2016-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Josephine G. Walker

    2014-12-01

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

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

    Science.gov (United States)

    Walker, Josephine G; Morgan, Eric R

    2014-12-01

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

  11. Caenorhabditis elegans: a simple nematode infection model for Penicillium marneffei.

    Directory of Open Access Journals (Sweden)

    Xiaowen Huang

    Full Text Available Penicillium marneffei, one of the most important thermal dimorphic fungi, is a severe threat to the life of immunocompromised patients. However, the pathogenic mechanisms of P. marneffei remain largely unknown. In this work, we developed a model host by using nematode Caenorhabditis elegans to investigate the virulence of P. marneffei. Using two P. marneffei clinical isolate strains 570 and 486, we revealed that in both liquid and solid media, the ingestion of live P. marneffei was lethal to C. elegans (P<0.001. Meanwhile, our results showed that the strain 570, which can produce red pigment, had stronger pathogenicity in C. elegans than the strain 486, which can't produce red pigment (P<0.001. Microscopy showed the formation of red pigment and hyphae within C. elegans after incubation with P. marneffei for 4 h, which are supposed to be two contributors in nematodes killing. In addition, we used C. elegans as an in vivo model to evaluate different antifungal agents against P. marneffei, and found that antifungal agents including amphotericin B, terbinafine, fluconazole, itraconazole and voriconazole successfully prolonged the survival of nematodesinfected by P. marneffei. Overall, this alternative model host can provide us an easy tool to study the virulence of P. marneffei and screen antifungal agents.

  12. Sugarcane straw and the populations of pests and nematodes

    Directory of Open Access Journals (Sweden)

    Leila Luci Dinardo-Miranda

    2013-10-01

    Full Text Available The green cane harvesting represented a significant change in sugarcane ecosystem due to the presence of straw left on the soil and to the absence of fire. These two factors may affect the populations of pests and their natural enemies. Among the pests benefit from the green cane harvesting stand out the spittlebug, Mahanarva fimbriolata, the curculionid Sphenophorus levis and sugarcane borer, Diatraea saccharalis. In areas of green cane harvesting, the population of these species grew faster than in areas of burnt cane. On the other hand, there are virtually no records of attacks by lesser cornstalk borers in areas of green cane harvesting. Populations of plant parasitic nematodes and the beetles Migdolus fryanus, very important pests of sugarcane, were apparently not affected by the green cane harvesting. Despite the absence of more consistent information, it appears that populations of ants and the giant borer Telchin licus can increase in green cane areas, due primarily to the difficulty of pest control. The partial or total removal of straw from the field represents an additional change to the ecosystem that could alter the status of pests and nematodes. It is likely that spittlebug, the curculionid S. levis and sugarcane borer populations decrease if a portion of the straw is removed from the field. However, the pest populations in areas where the straw is collected will not return to their original conditions at the time of burnt cane harvesting because the absence of fire will be maintained.

  13. Rogue sperm indicate sexually antagonistic coevolution in nematodes.

    Directory of Open Access Journals (Sweden)

    Ronald E Ellis

    2014-07-01

    Full Text Available Intense reproductive competition often continues long after animals finish mating. In many species, sperm from one male compete with those from others to find and fertilize oocytes. Since this competition occurs inside the female reproductive tract, she often influences the outcome through physical or chemical factors, leading to cryptic female choice. Finally, traits that help males compete with each other are sometimes harmful to females, and female countermeasures may thwart the interests of males, which can lead to an arms race between the sexes known as sexually antagonistic coevolution. New studies from Caenorhabditis nematodes suggest that males compete with each other by producing sperm that migrate aggressively and that these sperm may be more likely to win access to oocytes. However, one byproduct of this competition appears to be an increased probability that these sperm will go astray, invading the ovary, prematurely activating oocytes, and sometimes crossing basement membranes and leaving the gonad altogether. These harmful effects are sometimes observed in crosses between animals of the same species but are most easily detected in interspecies crosses, leading to dramatically lowered fitness, presumably because the competitiveness of the sperm and the associated female countermeasures are not precisely matched. This mismatch is most obvious in crosses involving individuals from androdioecious species (which have both hermaphrodites and males, as predicted by the lower levels of sperm competition these species experience. These results suggest a striking example of sexually antagonistic coevolution and dramatically expand the value of nematodes as a laboratory system for studying postcopulatory interactions.

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

    Science.gov (United States)

    Moravec, F; Scholz, T

    1991-01-01

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

  15. 959 Nematode Genomes: a semantic wiki for coordinating sequencing projects.

    Science.gov (United States)

    Kumar, Sujai; Schiffer, Philipp H; Blaxter, Mark

    2012-01-01

    Genome sequencing has been democratized by second-generation technologies, and even small labs can sequence metazoan genomes now. In this article, we describe '959 Nematode Genomes'--a community-curated semantic wiki to coordinate the sequencing efforts of individual labs to collectively sequence 959 genomes spanning the phylum Nematoda. The main goal of the wiki is to track sequencing projects that have been proposed, are in progress, or have been completed. Wiki pages for species and strains are linked to pages for people and organizations, using machine- and human-readable metadata that users can query to see the status of their favourite worm. The site is based on the same platform that runs Wikipedia, with semantic extensions that allow the underlying taxonomy and data storage models to be maintained and updated with ease compared with a conventional database-driven web site. The wiki also provides a way to track and share preliminary data if those data are not polished enough to be submitted to the official sequence repositories. In just over a year, this wiki has already fostered new international collaborations and attracted newcomers to the enthusiastic community of nematode genomicists. www.nematodegenomes.org.

  16. FAMILY OF FLP PEPTIDES IN CAENORHABDITIS ELEGANS AND RELATED NEMATODES

    Directory of Open Access Journals (Sweden)

    Chris eLi

    2014-10-01

    Full Text Available Neuropeptides regulate all aspects of behavior in multicellular organisms. Because of their ability to act at long distances, neuropeptides can exert their effects beyond the conventional synaptic connections, thereby adding an intricate layer of complexity to the activity of neural networks. In the nematode Caenorhabditis elegans, a large number of neuropeptide genes that are expressed throughout the nervous system has been identified. The actions of these peptides supplement the synaptic connections of the 302 neurons, allowing for fine tuning of neural networks and increasing the ways in which behaviors can be regulated. In this review, we focus on a large family of genes encoding FMRFamide-related peptides. These genes, the flp genes, have been used as a starting point to identifying flp genes throughout Nematoda. Nematodes have the largest family of FMRFamide-related peptides described thus far. The challenges in the future are the elucidation of their functions and the identification of the receptors and signaling pathways through which they function.

  17. Population dynamics of a host-specific root-feeding cyst nematode and resource quantity in the root zone of a clonal grass

    NARCIS (Netherlands)

    Van der Stoel, C.D.; Duyts, H.; Van der Putten, W.H.

    2006-01-01

    Recent studies have suggested that root-feeding nematodes influence plant community dynamics, but few studies have investigated the population dynamics of the nematodes. In coastal foredunes, feeding-specialist cyst nematodes (Heterodera spp.) are dominant in the soil nematode community and

  18. Population dynamics of host-specific root-feeding cyst nematode and resource quantity in the root zone of a clonal grass

    NARCIS (Netherlands)

    Stoel, C.D.; Duyts, H.; Putten, van der W.H.

    2006-01-01

    Recent studies have suggested that root-feeding nematodes influence plant community dynamics, but few studies have investigated the population dynamics of the nematodes. In coastal foredunes, feeding-specialist cyst nematodes (Heterodera spp.) are dominant in the soil nematode community and

  19. Functional Characterization of a Novel Class of Morantel-Sensitive Acetylcholine Receptors in Nematodes.

    Directory of Open Access Journals (Sweden)

    Elise Courtot

    2015-12-01

    Full Text Available Acetylcholine receptors are pentameric ligand-gated channels involved in excitatory neuro-transmission in both vertebrates and invertebrates. In nematodes, they represent major targets for cholinergic agonist or antagonist anthelmintic drugs. Despite the large diversity of acetylcholine-receptor subunit genes present in nematodes, only a few receptor subtypes have been characterized so far. Interestingly, parasitic nematodes affecting human or animal health possess two closely related members of this gene family, acr-26 and acr-27 that are essentially absent in free-living or plant parasitic species. Using the pathogenic parasitic nematode of ruminants, Haemonchus contortus, as a model, we found that Hco-ACR-26 and Hco-ACR-27 are co-expressed in body muscle cells. We demonstrated that co-expression of Hco-ACR-26 and Hco-ACR-27 in Xenopus laevis oocytes led to the functional expression of an acetylcholine-receptor highly sensitive to the anthelmintics morantel and pyrantel. Importantly we also reported that ACR-26 and ACR-27, from the distantly related parasitic nematode of horses, Parascaris equorum, also formed a functional acetylcholine-receptor highly sensitive to these two drugs. In Caenorhabditis elegans, a free-living model nematode, we demonstrated that heterologous expression of the H. contortus and P. equorum receptors drastically increased its sensitivity to morantel and pyrantel, mirroring the pharmacological properties observed in Xenopus oocytes. Our results are the first to describe significant molecular determinants of a novel class of nematode body wall muscle AChR.

  20. Partitioning yield loss on yellow squash into nematode and insect components.

    Science.gov (United States)

    McSorley, R; Waddill, V H

    1982-01-01

    The effect of a contplex of several insect and nematode pests on yield of yellow squash (Cucurbita pepo L.) was examined in two field tests in southern Florida. Applications of permethrin for insect control and oxamyl primarily for nematode control plus some insect control were made alone and in combination to achieve differential reduction of various insect and nematode components contributing to yield loss. The effect of these components on yield was further analyzed by multiple regression. Yield losses in weight of small fruit to nematode and insect pests together were estimated at 23.4% and 30.4% in each of the two tests, respectively. In the first test, this loss was attributed to the melonworm, Diaphania hyalinata, while in the second test, it was attributed to D. hyalinata and the nematodes Quinisulcius acutus and particularly Rotylenchulus reniforrnis. D. hyalinata accounted for further losses of 9.0% and 10.3%, respectively, from direct damage to the fruit. Despite the presence of low levels of Diabrotica balteata, Liriomyza sativae, and Myzus persicae, yields were little affected by these pests. Prediction of yield loss by multiple regression analysis was more accurate when both insect and nematode populations were present in the plots than when nematodes alone were present.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  2. A soil microcosm to test the effects of pollutants on soil nematode and microarthropod communities

    Energy Technology Data Exchange (ETDEWEB)

    Parmelee, R.W. [Ohio State Univ., Columbus, OH (United States). Dept. of Entomology; Wentsel, R.S.; Checkai, R.T.; Phillips, C.T. [Army CRDEC, Aberdeen Proving Ground, MD (United States); Bohlen, P.J. [Inst. of Ecosystem Studies, Millbrook, NY (United States)

    1995-12-31

    Previous studies have demonstrated that microcosms with field collected soil nematode and microarthropod communities are suitable model systems to detect effects of toxins on soil food web structure and function. The authors investigated the toxicity of copper, cadmium, malathion, and Aroclor 1254 to nematodes (total, bacterivores, fungivores, herbivores, omnivore-predators, hatchlings) and microarthropods (Prostigmata, Mesostigmata, Oribatida, Collembola, other arthropods). Nematodes were sensitive indicators of copper application, and total numbers were reduced at 100 {micro}g g{sup {minus}1}. Fungivore, bacterivore and omnivore-predators were the most susceptible trophic groups. Cadmium had no effects on either nematode or microarthropod communities. Microarthropods were more sensitive to malathion than nematodes, and total microarthropod abundance was lower than controls at 320 {micro}g g{sup {minus}1}. Prostigmatid mites and other arthropods were the most affected groups. Only the herbivore nematode trophic group was affected by malathion, and numbers did not decline until 1,280 {micro}g g{sup {minus}1}. Aroclor 1254 also had a greater negative impact on microarthropods than on nematodes. Total microarthropod abundance declined at 2,500 {micro}g g{sup {minus}1}, while there was no effect on nematodes. Prostigmatid and oribatid mites were the most susceptible groups to PCB application. Strong differential sensitivity between nematode and microarthropod communities indicates that both groups need to be examined to fully evaluate the impact of chemicals on soil systems. The authors conclude that microcosms with field-collected communities of soil microfauna offer high resolution of the ecotoxicological effects of chemicals in complex soil systems.

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

    Science.gov (United States)

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

    2013-05-01

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

  4. Interactions Between Nutrition and Infections With Haemonchus contortus and Related Gastrointestinal Nematodes in Small Ruminants.

    Science.gov (United States)

    Hoste, H; Torres-Acosta, J F J; Quijada, J; Chan-Perez, I; Dakheel, M M; Kommuru, D S; Mueller-Harvey, I; Terrill, T H

    2016-01-01

    Interactions between host nutrition and feeding behaviour are central to understanding the pathophysiological consequences of infections of the digestive tract with parasitic nematodes. The manipulation of host nutrition provides useful options to control gastrointestinal nematodes as a component of an integrated strategy. Focussed mainly on the Haemonchus contortus infection model in small ruminants, this chapter (1) illustrates the relationship between quantitative (macro- and micro-nutrients) and qualitative (plant secondary metabolites) aspects of host nutrition and nematode infection, and (2) shows how basic studies aimed at addressing some generic questions can help to provide solutions, despite the considerable diversity of epidemiological situations and breeding systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Trophic position of soil nematodes in boreal forests as indicated by stable isotope analysis

    Science.gov (United States)

    Kudrin, Alexey; Tsurikov, Sergey

    2016-04-01

    Despite the well-developed trophic classification of soil nematodes, their position in soil food webs is still little understood. Observed deviations from the typical feeding strategy indicate that a simplified trophic classification probably does not fully reflect actual trophic interactions. Furthermore, the extent and functional significance of nematodes as prey for other soil animals remains unknown. Stable isotope analysis (SIA) is powerful tool for investigating the structure of soil food webs, but its application to the study of soil nematodes has been limited to only a few studies. We used stable isotope analysis to gain a better understanding of trophic links of several groups of soil nematodes in two boreal forests on albeluvisol. We investigated four taxonomic groups of nematodes: Mononchida, Dorylaimida, Plectidae and Tylenchidae (mostly from the genus Filenchus), that according to the conventional trophic classification represent predators, omnivores, bacterivores and root-fungal feeders, respectively. To assess the trophic position of nematodes, we used a comparison against a set of reference species including herbivorous, saprophagous and predatory macro-invertebrates, oribatid and mesostigmatid mites, and collembolans. Our results suggest that trophic position of the investigated groups of soil nematodes generally corresponds to the conventional classification. All nematodes were enriched in 13C relative to Picea abies roots and litter, and mycorrhizal fungal mycelium. Root-fungal feeders Tylenchidae had δ15N values similar to those of earthworms, enchytraeids and Entomobrya collembolans, but slightly lower δ13C values. Bacterivorous Plectidae were either equal or enriched in 15N compared with saprophagous macroinvertebrates and most mesofauna species. Omnivorous Dorylaimida and predatory Mononchida were further enriched in 15N and their isotopic signature was similar to that of predatory arthropods. These data confirm a clear separation of

  6. Free-living marine nematodes from San Antonio Bay (Río Negro, Argentina)

    Science.gov (United States)

    Villares, Gabriela; Lo Russo, Virginia; Pastor de Ward, Catalina; Milano, Viviana; Miyashiro, Lidia; Mazzanti, Renato

    2016-01-01

    Abstract The dataset of free-living marine nematodes of San Antonio Bay is based on sediment samples collected in February 2009 during doctoral theses funded by CONICET grants. A total of 36 samples has been taken at three locations in the San Antonio Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for benthic biodiversity assessment of Patagonian nematodes as this area remains one of the least known regions. In total 7,743 specimens of free-living marine nematodes belonging to two classes, eight orders, 37 families, 94 genera and 104 species were collected. PMID:27110176

  7. Gastric nematodes of Nile crocodiles, Crocodylus niloticus Laurenti, 1768, in the Okavango River, Botswana

    Directory of Open Access Journals (Sweden)

    K. Junker

    2006-09-01

    Full Text Available The ascaridoid nematodes Dujardinascaris madagascariensis Chabaud & Caballero, 1966, Dujardinascaris dujardini (Travassos, 1920, Gedoelstascaris vandenbrandeni (Baylis, 1929 Sprent, 1978 and Multicaecum agile (Wedl, 1861 Baylis, 1923 were recovered from the stomach contents of Crocodylus niloticus Laurenti, 1768 from the Okavango River, Botswana, together with Eustrongylides sp., a dioctophymatoid nematode usually parasitizing piscivorous birds. Dujardinascaris madagascariensis was present in most of the infected hosts, while the remaining species were mostly represented in single collections in one to three hosts. All four ascaridoid nematodes represent new geographic records.

  8. Radiation-induced gene expression in the nematode Caenorhabditis elegans

    Science.gov (United States)

    Nelson, Gregory A.; Jones, Tamako A.; Chesnut, Aaron; Smith, Anna L.

    2002-01-01

    We used the nematode C. elegans to characterize the genotoxic and cytotoxic effects of ionizing radiation in a simple animal model emphasizing the unique effects of charged particle radiation. Here we demonstrate by RT-PCR differential display and whole genome microarray hybridization experiments that gamma rays, accelerated protons and iron ions at the same physical dose lead to unique transcription profiles. 599 of 17871 genes analyzed (3.4%) showed differential expression 3 hrs after exposure to 3 Gy of radiation. 193 were up-regulated, 406 were down-regulated and 90% were affected only by a single species of radiation. A novel statistical clustering technique identified the regulatory relationships between the radiation-modulated genes and showed that genes affected by each radiation species were associated with unique regulatory clusters. This suggests that independent homeostatic mechanisms are activated in response to radiation exposure as a function of track structure or ionization density.

  9. nGASP - the nematode genome annotation assessment project

    Energy Technology Data Exchange (ETDEWEB)

    Coghlan, A; Fiedler, T J; McKay, S J; Flicek, P; Harris, T W; Blasiar, D; Allen, J; Stein, L D

    2008-12-19

    While the C. elegans genome is extensively annotated, relatively little information is available for other Caenorhabditis species. The nematode genome annotation assessment project (nGASP) was launched to objectively assess the accuracy of protein-coding gene prediction software in C. elegans, and to apply this knowledge to the annotation of the genomes of four additional Caenorhabditis species and other nematodes. Seventeen groups worldwide participated in nGASP, and submitted 47 prediction sets for 10 Mb of the C. elegans genome. Predictions were compared to reference gene sets consisting of confirmed or manually curated gene models from WormBase. The most accurate gene-finders were 'combiner' algorithms, which made use of transcript- and protein-alignments and multi-genome alignments, as well as gene predictions from other gene-finders. Gene-finders that used alignments of ESTs, mRNAs and proteins came in second place. There was a tie for third place between gene-finders that used multi-genome alignments and ab initio gene-finders. The median gene level sensitivity of combiners was 78% and their specificity was 42%, which is nearly the same accuracy as reported for combiners in the human genome. C. elegans genes with exons of unusual hexamer content, as well as those with many exons, short exons, long introns, a weak translation start signal, weak splice sites, or poorly conserved orthologs were the most challenging for gene-finders. While the C. elegans genome is extensively annotated, relatively little information is available for other Caenorhabditis species. The nematode genome annotation assessment project (nGASP) was launched to objectively assess the accuracy of protein-coding gene prediction software in C. elegans, and to apply this knowledge to the annotation of the genomes of four additional Caenorhabditis species and other nematodes. Seventeen groups worldwide participated in nGASP, and submitted 47 prediction sets for 10 Mb of the C

  10. Gastrointestinal nematode control programs with an emphasis on cattle.

    Science.gov (United States)

    Stromberg, Bert E; Gasbarre, Louis C

    2006-11-01

    Control strategies for nematode parasites rely on knowledge of the relationships between the parasites and their hosts. Specifically, these programs are based on identifying crucial points of interaction in the environment provided by the host, including genetics and the immune response, and critical periods in the physical environment in which the eggs and larval stages must develop. When these targets are identified and the interactions understood, cost-effective sustainable programs can be developed using currently available antiparasitic compounds. Resistance to the major classes of anthelmintic compounds requires consideration of new approaches, such as immunity or genetics of the host. Additionally, the efficacy of these compounds can be expanded with combined or concomitant use. Increased study of the use of novel approaches, including fungi, elements such as copper, and plant products, has also occurred. This article explores each of these areas to allow readers to appreciate how various approaches may be developed and incorporated into an effective parasite control program.

  11. A survey of entomopathogenic nematode species in continental Portugal.

    Science.gov (United States)

    Valadas, V; Laranjo, M; Mota, M; Oliveira, S

    2014-09-01

    Entomopathogenic nematodes (EPN) are lethal parasites of insects, used as biocontrol agents. The objectives of this work were to survey the presence of EPN in continental Portugal and to characterize the different species. Of the 791 soil samples collected throughout continental Portugal, 53 were positive for EPN. Steinernema feltiae and Heterorhabditis bacteriophora were the two most abundant species. Analysis of EPN geographical distribution revealed an association between nematode species and vegetation type. Heterorhabditis bacteriophora was mostly found in the Alentejo region while S. feltiae was present in land occupied by agriculture with natural vegetation, broadleaved forest, mixed forest and transitional woodland-shrub, agro-forestry areas, complex cultivated patterns and non-irrigated arable land. Although no clear association was found between species and soil type, S. feltiae was typically recovered from cambisols and H. bacteriophora was more abundant in lithosols. Sequencing of the internal transcribed spacer (ITS) region indicated that S. feltiae was the most abundant species, followed by H. bacteriophora. Steinernema intermedium and S. kraussei were each isolated from one site and Steinernema sp. from two sites. Phylogenetic analyses of ITS, D2D3 expansion region of the 28S rRNA gene, as well as mitochondrial cytochrome c oxidase subunit I (COXI) and cytochrome b (cytb) genes, was performed to evaluate the genetic diversity of S. feltiae and H. bacteriophora. No significant genetic diversity was found among H. bacteriophora isolates. However, COXI seems to be the best marker to study genetic diversity of S. feltiae. This survey contributes to the understanding of EPN distribution in Europe.

  12. Depolymerization-driven flow and the crawling of nematode sperm

    Science.gov (United States)

    Wolgemuth, Charles

    2008-03-01

    Cell crawling motility is integral in many biological and biomedical processes, such as wound healing, cancer metastasis, and morphogenesis. A complete understanding of the mechanisms by which cells crawl is still lacking, but it is known to entail at least three separate physical processes: (i) cytoskeletal extension at the front of the cell; (ii) adhesion to the substrate at the cell front and release at the rear; and (iii) advance of the cell body. In most cells, the cytoskeletal network is composed of actin. The mechanism by which force is generated to drive translocation of the cell body is still debated. Originally, this force was attributed to an actomyosin system similar to muscle. However, nematode sperm utilize a cytoskeleton composed of a network of Major Sperm Protein (MSP) that forms non-polar filaments for which molecular motors have not been identified. The motility of these cells still exhibits all three fundamental processes required for standard crawling motility. Experiments suggest that depolymerization of the cytoskeletal network is the force-producing mechanism for pulling up the rear. In this talk I will present a mechanical model that describes how depolymerization of the cytoskeleton can drive motility. This model accounts for both cytoskeletal displacements and cytsolic (the fluid component of the cell) flow. The model accurately fits in vitro data using nematode sperm extracts where depolymerization induces contraction of MSP polymer bundles. Application of this model to cell crawling produces testable predictions about how the size and shape of a cell affect crawling speed. Experiments using Caenorhabditis elegans sperm show good agreement with the model predictions. Interestingly, the model requires that cells are anisotropically elastic, being more stiff in the direction of motion than perpendicular to it. A simple physical picture can account for this anisotropy. The model also predicts that cell speed increases with anisotropy and

  13. Gene expression and pharmacology of nematode NLP-12 neuropeptides.

    Science.gov (United States)

    McVeigh, Paul; Leech, Suzie; Marks, Nikki J; Geary, Timothy G; Maule, Aaron G

    2006-05-31

    This study examines the biology of NLP-12 neuropeptides in Caenorhabditis elegans, and in the parasitic nematodes Ascaris suum and Trichostrongylus colubriformis. DYRPLQFamide (1 nM-10 microM; n > or =6) produced contraction of innervated dorsal and ventral Ascaris body wall muscle preparations (10 microM, 6.8+/-1.9 g; 1 microM, 4.6+/-1.8 g; 0.1 microM, 4.1+/-2.0 g; 10 nM, 3.8+/-2.0 g; n > or =6), and also caused a qualitatively similar, but quantitatively lower contractile response (10 microM, 4.0+/-1.5 g, n=6) on denervated muscle strips. Ovijector muscle displayed no measurable response (10 microM, n=5). nlp-12 cDNAs were characterised from A. suum (As-nlp-12) and T. colubriformis (Tc-nlp-12), both of which show sequence similarity to C. elegans nlp-12, in that they encode multiple copies of -LQFamide peptides. In C. elegans, reverse transcriptase (RT)-PCR analysis showed that nlp-12 was transcribed throughout the life cycle, suggesting that DYRPLQFamide plays a constitutive role in the nervous system of this nematode. Transcription was also identified in both L3 and adult stages of T. colubriformis, in which Tc-nlp-12 is expressed in a single tail neurone. Conversely, As-nlp-12 is expressed in both head and tail tissue of adult female A. suum, suggesting species-specific differences in the transcription pattern of this gene.

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

    Science.gov (United States)

    Lok, J. B.; Artis, D.

    2011-01-01

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

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

    Science.gov (United States)

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

  16. Molecular phylogenetics and the evolution of host plant associations in the nematode genus Fergusobia (Tylenchida: Fergusobiinae)

    Science.gov (United States)

    Fergusobia nematodes (Tylenchida: Fergusobiinae) and Fergusonina flies (Diptera: Fergusoninidae) are mutualists that develop together in galls formed in meristematic tissues of many species of the plant family Myrtaceae in Australasia. Evolutionary relationships of Fergusobia species were inferred f...

  17. Community diversity, structure and carbon footprint of nematode food web following reforestation on degraded Karst soil

    Science.gov (United States)

    Hu, Ning; Li, Hui; Tang, Zheng; Li, Zhongfang; Tian, Jing; Lou, Yilai; Li, Jianwei; Li, Guichun; Hu, Xiaomin

    2016-01-01

    We examined community diversity, structure and carbon footprint of nematode food web along a chronosequence of T. Sinensis reforestation on degraded Karst. In general, after the reforestation: a serious of diversity parameters and community indices (Shannon-Weinier index (H′), structure index (SI), etc.) were elevated; biomass ratio of fungivores to bacterivores (FFC/BFC), and fungi to bacteria (F/B) were increased, and nematode channel ratio (NCR) were decreased; carbon footprints of all nematode trophic groups, and biomass of bacteria and fungi were increased. Our results indicate that the Karst aboveground vegetation restoration was accompanied with belowground nematode food web development: increasing community complexity, function and fungal dominance in decomposition pathway, and the driving forces included the bottom-up effect (resource control), connectedness of functional groups, as well as soil environments. PMID:27311984

  18. Community diversity, structure and carbon footprint of nematode food web following reforestation on degraded Karst soil.

    Science.gov (United States)

    Hu, Ning; Li, Hui; Tang, Zheng; Li, Zhongfang; Tian, Jing; Lou, Yilai; Li, Jianwei; Li, Guichun; Hu, Xiaomin

    2016-06-17

    We examined community diversity, structure and carbon footprint of nematode food web along a chronosequence of T. Sinensis reforestation on degraded Karst. In general, after the reforestation: a serious of diversity parameters and community indices (Shannon-Weinier index (H'), structure index (SI), etc.) were elevated; biomass ratio of fungivores to bacterivores (FFC/BFC), and fungi to bacteria (F/B) were increased, and nematode channel ratio (NCR) were decreased; carbon footprints of all nematode trophic groups, and biomass of bacteria and fungi were increased. Our results indicate that the Karst aboveground vegetation restoration was accompanied with belowground nematode food web development: increasing community complexity, function and fungal dominance in decomposition pathway, and the driving forces included the bottom-up effect (resource control), connectedness of functional groups, as well as soil environments.

  19. Population dynamics of potato cyst nematodes and associated damage to potato

    NARCIS (Netherlands)

    Schans, J.

    1993-01-01

    Population dynamics of potato cyst nematodes (PCN; Globoderarostochiensis (Woll.) Skarbilovich and G. pallida Stone) and their interactions with potato plants are insufficiently understood to explain variations of population

  20. Nematode response to metal, PAHs and organic enrichment in tourist marinas of the Mediterranean Sea.

    Science.gov (United States)

    Moreno, M; Albertelli, G; Fabiano, M

    2009-08-01

    The structure of nematode assemblages was investigated in the sediments of two different tourist marinas in the Mediterranean Sea and related to pollution variables. Nematode densities and generic compositions were determined, as were concentrations of heavy metals, PAHs and organic matter. Results showed different assemblages at the two marinas, with a dominance of the genera Paralongicyatholaimus and Daptonema. Significant correlations between nematodes and concentrations of environmental contaminants were found. In particular, Paralongicyatholaimus showed a significant negative correlation with Cu concentrations and was almost absent at the stations where higher Cu concentrations were found. The presence of sensitive/tolerant nematode genera represents a promising tool to identify areas subjected to a higher level of disturbance and to define the correct environmental management strategy for harbors.

  1. On the track of the Red Queen: bark beetles, their nematodes, local climate and geographic parthenogenesis.

    Science.gov (United States)

    Meirmans, S; Skorping, A; Løyning, M K; Kirkendall, L R

    2006-11-01

    Geographic parthenogenesis has been explained as resulting from parasite pressure (Red Queen hypothesis): several studies have found high degrees of sexuals where the prevalence of parasites is high. However, it is important to address whether prevalence of parasites mirrors risk of infection. We explored geographic parthenogenesis of Ips acuminatus bark beetles and their nematodes. Local climate is crucial for nematode stages outside the host, in spring and summer, and prevalence should thus be associated with those temperatures if prevalence reliably reflects exposure risk across populations. This was the case; however, high prevalence of a virulent nematode species was not associated with many sexuals, whereas highly sexual populations were characterized by high infection risk of benign nematodes. Low virulence of the latter makes Red Queen dynamics unlikely. Geographical patterns of parthenogenesis were instead associated with winter temperature and variance in temperature.

  2. 'David and Goliath' of the soil food web - Flagellates that kill nematodes

    DEFF Research Database (Denmark)

    Strandmark, Lisa Bjørnlund; Rønn, Regin

    2008-01-01

    Nematodes and flagellates are important bacterial predators in soil and sediments. Generally, these organisms are considered to be competitors for bacterial food. We studied the interaction among flagellates and nematodes using axenic liquid cultures amended with heat-killed bacteria as food...... and showed for the first time that a small and common soil flagellate (Cercomonas sp.) is able to attack and kill the much larger nematode Caenorhabditis elegans. The killing process is not caused by soluble metabolites but requires direct contact between the flagellate cells and the nematode surface...... bacterial feeder can control the abundance of another, suggests a new perspective on how bacterial diversity and trophic interactions are linked in the soil food web. (C) 2008 Elsevier Ltd. All rights reserved Udgivelsesdato: 2008...

  3. Plant and soil nematodes: societal impact and focus for the future.

    Science.gov (United States)

    Barker, K R; Hussey, R S; Krusberg, L R; Bird, G W; Dunn, R A; Ferris, H; Ferris, V R; Freckman, D W; Gabriel, C J; Grewal, P S; Macguidwin, A E; Riddle, D L; Roberts, P A; Schmitt, D P

    1994-06-01

    Plant and soil nematodes significandy impact our lives. Therefore, we must understand and manage these complex organisms so that we may continue to develop and sustain our food production systems, our natural resources, our environment, and our quality of life. This publication looks specifically at soil and plant nematology. First, the societal impact of nematodes and benefits of nematology research are briefly presented. Next, the opportunities facing nematology in the next decade are outlined, as well as the resources needed to address these priorities. The safety and sustainability of U.S. food and fiber production depends on public and administrative understanding of the importance of nematodes, the drastic effects of nematodes on many agricultural and horticultural crops, and the current research priorities of nematology.

  4. Community diversity, structure and carbon footprint of nematode food web following reforestation on degraded Karst soil

    Science.gov (United States)

    Hu, Ning; Li, Hui; Tang, Zheng; Li, Zhongfang; Tian, Jing; Lou, Yilai; Li, Jianwei; Li, Guichun; Hu, Xiaomin

    2016-06-01

    We examined community diversity, structure and carbon footprint of nematode food web along a chronosequence of T. Sinensis reforestation on degraded Karst. In general, after the reforestation: a serious of diversity parameters and community indices (Shannon-Weinier index (H‧), structure index (SI), etc.) were elevated; biomass ratio of fungivores to bacterivores (FFC/BFC), and fungi to bacteria (F/B) were increased, and nematode channel ratio (NCR) were decreased; carbon footprints of all nematode trophic groups, and biomass of bacteria and fungi were increased. Our results indicate that the Karst aboveground vegetation restoration was accompanied with belowground nematode food web development: increasing community complexity, function and fungal dominance in decomposition pathway, and the driving forces included the bottom-up effect (resource control), connectedness of functional groups, as well as soil environments.

  5. Effect of soil properties, heavy metals and emerging contaminants in the soil nematodes diversity.

    Science.gov (United States)

    Gutiérrez, Carmen; Fernández, Carlos; Escuer, Miguel; Campos-Herrera, Raquel; Beltrán Rodríguez, Mª Eulalia; Carbonell, Gregoria; Rodríguez Martín, Jose Antonio

    2016-06-01

    Among soil organisms, nematodes are seen as the most promising candidates for bioindications of soil health. We hypothesized that the soil nematode community structure would differ in three land use areas (agricultural, forest and industrial soils), be modulated by soil parameters (N, P, K, pH, SOM, CaCO3, granulometric fraction, etc.), and strongly affected by high levels of heavy metals (Cd, Pb, Zn, Cr, Ni, Cu, and Hg) and emerging contaminants (pharmaceuticals and personal care products, PPCPs). Although these pollutants did not significantly affect the total number of free-living nematodes, diversity and structure community indices vastly altered. Our data showed that whereas nematodes with r-strategy were tolerant, genera with k-strategy were negatively affected by the selected pollutants. These effects diminished in soils with high levels of heavy metals given their adaptation to the historical pollution in this area, but not to emerging pollutants like PPCPs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Response of free-living marine nematodes to the southern Yellow Sea Cold Water Mass.

    Science.gov (United States)

    Xu, Man; Liu, Qinghe; Zhang, Zhinan; Liu, Xiaoshou

    2016-04-15

    The Yellow Sea Cold Water Mass is a remarkable seasonal hydrographic event in the bottom water of the Yellow Sea. In order to reveal the response of free-living marine nematodes to this event, community structure and biodiversity indices of nematodes were studied in June and November 2013. The dominant species were Dorylaimopsis rabalaisi, Spilophorella sp., Daptonema sp., Sabatieria sp. and Parasphaerolaimus sp. In terms of trophic structure, epigrowth feeders were the most dominant group. Correlation analysis showed that Shannon-Wiener diversity index had significantly negative correlation with sediment silt-clay percentage, organic matter content and water content. Results of BIOENV indicated that sediment phaeophorbide content, water content, bottom water salinity and temperature were the most important factors related to nematode community. In conclusion, community structure and biodiversity indices of nematodes were consistent in the two sampling seasons. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Linear distribution of nematodes in the gastrointestinal tract of tracer lambs

    Czech Academy of Sciences Publication Activity Database

    Makovcová, K.; Langrová, I.; Vadlejch, J.; Jankovská, I.; Lytvynets, Andrej; Borkovcová, M.

    2008-01-01

    Roč. 104, č. 1 (2008), s. 123-126 ISSN 0932-0113 Institutional research plan: CEZ:AV0Z50110509 Keywords : distribution * nematode s * sheep Subject RIV: EG - Zoology Impact factor: 1.473, year: 2008

  8. Differential Selection by Nematodes on an Introduced Biocontrol Fungus vs. Indigenous Fungi in Nonsterile Soil.

    Science.gov (United States)

    Kim, Tae Gwan; Knudsen, Guy R

    2018-03-15

    Trophic interactions of introduced biocontrol fungi with soil animals can bea key determinant in the fungal proliferation and activity.This study investigated trophic interaction of an introduced biocontrol fungus with soil nematodes. The biocontrol fungus Trichoderma harzianum ThzID1-M3 and the fungivorous nematode Aphelenchoides sp. (10 per gram of soil) were added to nonsterile soil, and microbial populations were monitored for 40 days. Similar results were obtained when the experiment was duplicated. ThzID1-M3 stimulated the population growth of indigenous nematodes ( p fungus when densely localized did.The results suggest that soil fungivorous nematodes are an important constraint onhyphal proliferation of fungal agents introduced into natural soils.

  9. Nematode species diversity as indicator of stressed benthic environment along the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nanajkar, M.R.; Ingole, B.S.

    Deterioration or recovery of a marine habitat from perturbation depends on the target community subjected for exposure and its sensitivity to respond to the change. In the present study, we demonstrated the utility of free-living marine nematode...

  10. Desiccation survival in an Antarctic nematode: molecular analysis using expressed sequenced tags

    Directory of Open Access Journals (Sweden)

    Wall Diana H

    2009-02-01

    Full Text Available Abstract Background Nematodes are the dominant soil animals in Antarctic Dry Valleys and are capable of surviving desiccation and freezing in an anhydrobiotic state. Genes induced by desiccation stress have been successfully enumerated in nematodes; however we have little knowledge of gene regulation by Antarctic nematodes which can survive multiple environmental stresses. To address this problem we investigated the genetic responses of a nematode species, Plectus murrayi, that is capable of tolerating Antarctic environmental extremes, in particular desiccation and freezing. In this study, we provide the first insight into the desiccation induced transcriptome of an Antarctic nematode through cDNA library construction and suppressive subtractive hybridization. Results We obtained 2,486 expressed sequence tags (ESTs from 2,586 clones derived from the cDNA library of desiccated P. murrayi. The 2,486 ESTs formed 1,387 putative unique transcripts of which 523 (38% had matches in the model-nematode Caenorhabditis elegans, 107 (7% in nematodes other than C. elegans, 153 (11% in non-nematode organisms and 605 (44% had no significant match to any sequences in the current databases. The 1,387 unique transcripts were functionally classified by using Gene Ontology (GO hierarchy and the Kyoto Encyclopedia of Genes and Genomes (KEGG database. The results indicate that the transcriptome contains a group of transcripts from diverse functional areas. The subtractive library of desiccated nematodes showed 80 transcripts differentially expressed during desiccation stress, of which 28% were metabolism related, 19% were involved in environmental information processing, 28% involved in genetic information processing and 21% were novel transcripts. Expression profiling of 14 selected genes by quantitative Real-time PCR showed 9 genes significantly up-regulated, 3 down-regulated and 2 continuously expressed in response to desiccation. Conclusion The establishment of a

  11. Potential of Tissue Culture for Breeding Root-Knot Nematode Resistance into Vegetables

    OpenAIRE

    Fassuliotis, G.; Bhatt, D. P.

    1982-01-01

    Plant protoplast technology is being investigated as a means of transferring root-knot nematode resistance factors from Solanum sisymbriifolium into the susceptible S. melongena. Solanum sisymbriifolium plants regenerated from callus lost resistance to Meloidogyne javanica but retained resistance to M. incognita. Tomato plants cloned from leaf discs of the root-knot nematode resistant 'Patriot' were completely susceptible to M. incognita, while sections of stems and leaves rooted in sand in t...

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

    Directory of Open Access Journals (Sweden)

    N.R. Devi

    2009-12-01

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

  13. Benthic-pelagic coupling: effects on nematode communities along southern European continental margins.

    Directory of Open Access Journals (Sweden)

    Ellen Pape

    Full Text Available Along a west-to-east axis spanning the Galicia Bank region (Iberian margin and the Mediterranean basin, a reduction in surface primary productivity and in seafloor flux of particulate organic carbon was mirrored in the in situ organic matter quantity and quality within the underlying deep-sea sediments at different water depths (1200, 1900 and 3000 m. Nematode standing stock (abundance and biomass and genus and trophic composition were investigated to evaluate downward benthic-pelagic coupling. The longitudinal decline in seafloor particulate organic carbon flux was reflected by a reduction in benthic phytopigment concentrations and nematode standing stock. An exception was the station sampled at the Galicia Bank seamount, where despite the maximal particulate organic carbon flux estimate, we observed reduced pigment levels and nematode standing stock. The strong hydrodynamic forcing at this station was believed to be the main cause of the local decoupling between pelagic and benthic processes. Besides a longitudinal cline in nematode standing stock, we noticed a west-to-east gradient in nematode genus and feeding type composition (owing to an increasing importance of predatory/scavenging nematodes with longitude governed by potential proxies for food availability (percentage of nitrogen, organic carbon, and total organic matter. Within-station variability in generic composition was elevated in sediments with lower phytopigment concentrations. Standing stock appeared to be regulated by sedimentation rates and benthic environmental variables, whereas genus composition covaried only with benthic environmental variables. The coupling between deep-sea nematode assemblages and surface water processes evidenced in the present study suggests that it is likely that climate change will affect the composition and function of deep-sea nematodes.

  14. Changes in plant species richness induce functional shifts in soil nematode communities in experimental grassland.

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    Nico Eisenhauer

    Full Text Available Changes in plant diversity may induce distinct changes in soil food web structure and accompanying soil feedbacks to plants. However, knowledge of the long-term consequences of plant community simplification for soil animal food webs and functioning is scarce. Nematodes, the most abundant and diverse soil Metazoa, represent the complexity of soil food webs as they comprise all major trophic groups and allow calculation of a number of functional indices.We studied the functional composition of nematode communities three and five years after establishment of a grassland plant diversity experiment (Jena Experiment. In response to plant community simplification common nematode species disappeared and pronounced functional shifts in community structure occurred. The relevance of the fungal energy channel was higher in spring 2007 than in autumn 2005, particularly in species-rich plant assemblages. This resulted in a significant positive relationship between plant species richness and the ratio of fungal-to-bacterial feeders. Moreover, the density of predators increased significantly with plant diversity after five years, pointing to increased soil food web complexity in species-rich plant assemblages. Remarkably, in complex plant communities the nematode community shifted in favour of microbivores and predators, thereby reducing the relative abundance of plant feeders after five years.The results suggest that species-poor plant assemblages may suffer from nematode communities detrimental to plants, whereas species-rich plant assemblages support a higher proportion of microbivorous nematodes stimulating nutrient cycling and hence plant performance; i.e. effects of nematodes on plants may switch from negative to positive. Overall, food web complexity is likely to decrease in response to plant community simplification and results of this study suggest that this results mainly from the loss of common species which likely alter plant-nematode interactions.

  15. THE ABUNDANCE, DIVERSITY AND METABOLIC FOOTPRINT OF SOIL NEMATODES IS HIGHEST IN HIGH ELEVATION ALPINE GRASSLANDS

    Directory of Open Access Journals (Sweden)

    Alan Kergunteuil

    2016-07-01

    Full Text Available Nematodes are key components of soil biodiversity and represent valuable bio-indicators of soil food webs. Numerous community indices have been developed in order to track variations in soil ecosystem processes, but their use is mainly restricted to anthropogenic stresses. In this study, we propose to expand the use of nematodes’ derived ecological indices in order to shed light on variations of soil food webs in natural systems distributed along elevation gradients. For this purpose, we aimed at determining how elevation affects the community structure and the trophic diversity by studying the abundance, the composition and the functional diversity of nematode communities. Nematode communities were sampled every 200 m across five transects that span about 2000 m in elevation in the Alps. To understand the underlying ecological parameters driving these patterns we studied both abiotic factors (soil properties and biotic factors (trophic links, relationships with plant diversity. We found that (1 nematode abundance increases with elevation of lowland forests and alpine meadows; (2 differences in nematodes communities rely on habitat-specific functional diversity (e.g. tolerance to harsh environments, colonizer/persister status while most trophic groups are ubiquitous; and (3 the metabolic footprint of the complete nematode community increases with elevation. We thus conclude that the contribution of soil dwelling nematodes to belowground ecosystem processes, including carbon and energy flow, is stronger at high elevation. The resulting cascading effects on the soil food web structure are discussed from an ecosystem functioning perspective. Overall, this study highlights the importance of nematodes in soil ecosystems and brings insights in their enhanced role along ecological gradients.

  16. Changes in plant species richness induce functional shifts in soil nematode communities in experimental grassland.

    Science.gov (United States)

    Eisenhauer, Nico; Migunova, Varvara D; Ackermann, Michael; Ruess, Liliane; Scheu, Stefan

    2011-01-01

    Changes in plant diversity may induce distinct changes in soil food web structure and accompanying soil feedbacks to plants. However, knowledge of the long-term consequences of plant community simplification for soil animal food webs and functioning is scarce. Nematodes, the most abundant and diverse soil Metazoa, represent the complexity of soil food webs as they comprise all major trophic groups and allow calculation of a number of functional indices. We studied the functional composition of nematode communities three and five years after establishment of a grassland plant diversity experiment (Jena Experiment). In response to plant community simplification common nematode species disappeared and pronounced functional shifts in community structure occurred. The relevance of the fungal energy channel was higher in spring 2007 than in autumn 2005, particularly in species-rich plant assemblages. This resulted in a significant positive relationship between plant species richness and the ratio of fungal-to-bacterial feeders. Moreover, the density of predators increased significantly with plant diversity after five years, pointing to increased soil food web complexity in species-rich plant assemblages. Remarkably, in complex plant communities the nematode community shifted in favour of microbivores and predators, thereby reducing the relative abundance of plant feeders after five years. The results suggest that species-poor plant assemblages may suffer from nematode communities detrimental to plants, whereas species-rich plant assemblages support a higher proportion of microbivorous nematodes stimulating nutrient cycling and hence plant performance; i.e. effects of nematodes on plants may switch from negative to positive. Overall, food web complexity is likely to decrease in response to plant community simplification and results of this study suggest that this results mainly from the loss of common species which likely alter plant-nematode interactions.

  17. Why Do Sleeping Nematodes Adopt a Hockey-Stick-Like Posture?

    OpenAIRE

    Tramm, Nora; Oppenheimer, Naomi; Nagy, Stanislav; Efrati, Efi; Biron, David

    2014-01-01

    A characteristic posture is considered one of the behavioral hallmarks of sleep, and typically includes functional features such as support for the limbs and shielding of sensory organs. The nematode C. elegans exhibits a sleep-like state during a stage termed lethargus, which precedes ecdysis at the transition between larval stages. A hockey-stick-like posture is commonly observed during lethargus. What might its function be? It was previously noted that during lethargus, C. elegans nematode...

  18. EFFECT OF SOIL FERTILITY MANAGEMENT PRACTICES ON NEMATODE DESTROYING FUNGI IN TAITA, KENYA

    Directory of Open Access Journals (Sweden)

    Peter M Wachira

    2010-10-01

    Full Text Available The effect of soil fertility management practices on nematode destroying fungi was investigated for three seasons in Taita, Kenya. The study aimed at identifying soil fertility practice that promoted nematode destroying fungi in the soil. Field experiments were established in Taita district, the treatments comprised of Mavuno fertilizer, Triple super- phosphate and calcium ammonium nitrate (TSP+CAN, cow manure and a control where no amendments were applied. This experiment was replicated in ten farms and repeated in three planting seasons. Isolation of nematode destroying fungi carried out was using the soil sprinkle technique and the isolates were identified using the key described by Cooke and Godfrey (1964. There were significant difference (P= 1.705 x 10-06 in occurrence of the nematode destroying fungi between soil fertility treatments. The highest mean (1.6 occurrence of nematode destroying fungi was recorded in soils amended with cow manure and the least (0.7 was recorded in soils from the control plots. A mean of 0.78 was recorded in soils from both TSP+CAN and Mavuno fertilizers. Plots amended with cow manure presented the highest diversity of nematodes followed by the control, then TSP+CAN and least in Mavuno with shannon indices of 0.34, 0.15, 0.13 and 0.11 respectively. Sixty percent of all the isolated nematode destroying fungi genera were from plots treated with cow manure and only twenty percent were from plots amended with the inorganic fertilizer. The control plots recorded higher number of nematode destroying fungi compared to the soils that received inorganic fertilizers.

  19. Two Entomophagous Isolated From Sumatera Utara; Potential as Biocontrol Agent Againts Nematode

    OpenAIRE

    Hastuti, Liana Dwi Sri; Nicklin, Jane; Siregar, Ameilia Zuliyanti

    2016-01-01

    Two species of nematophagous fungi has been isolated from Sumatera Utara soil, with an aim of harnessing their potential in the biological control of plant parasitic nematodes or animal parasitic nematodes in Indonesia, especially in Sumatera Utara. Soil samples were collected from tobacco plantations, vegetable fields and ornamental plantings in the Berastagi area, and also from livestock in local farms and a dairy farm in Berastagi Area, Karo Regency. Soil also collected from un-cultivated ...

  20. A unique cytoskeleton associated with crawling in the amoeboid sperm of the nematode, Ascaris suum

    OpenAIRE

    1989-01-01

    Nematode sperm extend pseudopods and pull themselves over substrates. They lack an axoneme or the actin and myosins of other types of motile cells, but their pseudopods contain abundant major sperm protein (MSP), a family of 14-kD polypeptides found exclusively in male gametes. Using high voltage electron microscopy, a unique cytoskeleton was discovered in the pseudopod of in vitro-activated, crawling sperm of the pig intestinal nematode Ascaris suum. It consists of 5-10-nm fuzzy fibers organ...

  1. Ammonia concentration at emergence and its effects on the recovery of different species of entomopathogenic nematodes.

    Science.gov (United States)

    San-Blas, Ernesto; Pirela, Deynireth; García, Dana; Portillo, Edgar

    2014-09-01

    The life cycle of entomopathogenic nematodes (EPN) occurs inside an insect cadaver and an accumulation of ammonia initiates as a consequence of the nematodes defecation. This accumulation reduces the food resources quality and creates a detrimental environment for nematodes. When a given ammonia concentration is reached, the nematodes start their emergence process, searching for a new host. In the present work, this parameter, ammonia triggering point (ATP) was measured in 7 Steinernema species/strains. The effect of different ammonia concentrations on the recovery process and their consequences in the nematodes survival were also investigated. The results indicate that ATP varies among nematode species; Steinernema glaseri showed the highest ATP of the evaluated species (1.98±2.6 mg of NH4-N*g of Galleria mellonella(-1)); whereas Steinernema riobrave presented the lowest ATP (1.16±0.1 mg of NH4-N*g of G. mellonella(-1)). On the other hand, the nematode emergence could be a repulsive response when ATP is reached. As the ammonia concentration increased the recovery percentage of Steinernema feltiae (Chile strain) dropped gradually from 79.4±11.9% in the control treatment to 0% when 1mg of NH4-N*ml of bacterial broth(-1) was added. It is possible, that emergence process could be a repulsive response of the nematodes due to ammonia concentration when is reaching the ATP. The role of ammonia inside the insect cadavers, might suggests connections with some stages of the EPN life cycle. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Control of Soybean Cyst Nematode by Chitinolytic Bacteria with Chitin Substrate

    OpenAIRE

    Tian, Honglin; Riggs, Robert D.; Crippen, Devany L.

    2000-01-01

    Sixty-four chitinolytic bacterial isolates from soybean fields in Arkansas were tested for suppression of soybean cyst nematode (Heterodera glycines) in a heat-treated silt loam soil amended with 0.6% (w/w) chitin in a greenhouse. Five isolates consistently reduced numbers of H. glycines compared to controls receiving neither chitin nor bacteria, or only chitin. Four of the five isolates interacted with the chitin substrate to enhance its effectiveness in reducing numbers of the nematode. The...

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

    Directory of Open Access Journals (Sweden)

    Katarzyna Donskow-Łysoniewska

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

  4. Free-living marine nematodes from San Antonio Bay (Río Negro, Argentina)

    OpenAIRE

    Villares, Gabriela; Russo, Virginia Lo; Ward, Catalina Pastor de; Milano, Viviana; Miyashiro, Lidia; Mazzanti, Renato

    2016-01-01

    Abstract The dataset of free-living marine nematodes of San Antonio Bay is based on sediment samples collected in February 2009 during doctoral theses funded by CONICET grants. A total of 36 samples has been taken at three locations in the San Antonio Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for benthic biodiversity assessment of Patagonian nematodes as this area remains one of the least known regions. I...

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

    Directory of Open Access Journals (Sweden)

    Oniki Yoshika

    2002-01-01

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

  6. The nematode C. elegans - A model animal system for the detection of genetic and developmental lesions

    Science.gov (United States)

    Nelson, Gregory A.; Marshall, Tamara M.; Schubert, Wayne W.

    1989-01-01

    The effects of ionizing and nonionizing radiation effects on cell reproduction, differentiation, and mutation in vivo are studied using the nematode C. elegans. The relationships between fluence/dose and response and quality factor and linear energy transfer are analyzed. The data reveal that there is a complex repair pathway in the nematode and that mutants can be used to direct the sensitivity of the system to specific mutagens/radiation types.

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

    Science.gov (United States)

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

    2017-04-01

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

  8. Mind the gaps in research on the control of gastrointestinal nematodes of farmed ruminants and pigs.

    Science.gov (United States)

    Charlier, J; Thamsborg, S M; Bartley, D J; Skuce, P J; Kenyon, F; Geurden, T; Hoste, H; Williams, A R; Sotiraki, S; Höglund, J; Chartier, C; Geldhof, P; van Dijk, J; Rinaldi, L; Morgan, E R; von Samson-Himmelstjerna, G; Vercruysse, J; Claerebout, E

    2017-11-10

    Gastrointestinal (GI) nematode control has an important role to play in increasing livestock production from a limited natural resource base and to improve animal health and welfare. In this synthetic review, we identify key research priorities for GI nematode control in farmed ruminants and pigs, to support the development of roadmaps and strategic research agendas by governments, industry and policymakers. These priorities were derived from the DISCONTOOLS gap analysis for nematodes and follow-up discussions within the recently formed Livestock Helminth Research Alliance (LiHRA). In the face of ongoing spread of anthelmintic resistance (AR), we are increasingly faced with a failure of existing control methods against GI nematodes. Effective vaccines against GI nematodes are generally not available, and anthelmintic treatment will therefore remain a cornerstone for their effective control. At the same time, consumers and producers are increasingly concerned with environmental issues associated with chemical parasite control. To address current challenges in GI nematode control, it is crucial to deepen our insights into diverse aspects of epidemiology, AR, host immune mechanisms and the socio-psychological aspects of nematode control. This will enhance the development, and subsequent uptake, of the new diagnostics, vaccines, pharma-/nutraceuticals, control methods and decision support tools required to respond to the spread of AR and the shifting epidemiology of GI nematodes in response to climatic, land-use and farm husbandry changes. More emphasis needs to be placed on the upfront evaluation of the economic value of these innovations as well as the socio-psychological aspects to prioritize research and facilitate uptake of innovations in practice. Finally, targeted regulatory guidance is needed to create an innovation-supportive environment for industries and to accelerate the access to market of new control tools. © 2017 Blackwell Verlag GmbH.

  9. Serotonin Drives Predatory Feeding Behavior via Synchronous Feeding Rhythms in the Nematode Pristionchus pacificus

    OpenAIRE

    Okumura, Misako; Wilecki, Martin; Sommer, Ralf J.

    2017-01-01

    Feeding behaviors in a wide range of animals are regulated by the neurotransmitter serotonin, although the exact neural circuits and associated mechanism are often unknown. The nematode Pristionchus pacificus can kill other nematodes by opening prey cuticles with movable teeth. Previous studies showed that exogenous serotonin treatment induces a predatory-like tooth movement and slower pharyngeal pumping in the absence of prey; however, physiological functions of serotonin during predation an...

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

    Science.gov (United States)

    Rae, R

    2017-07-06

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

  11. Influence of industrial heavy metal pollution on soil free-living nematode population

    International Nuclear Information System (INIS)

    Pen-Mouratov, Stanislav; Shukurov, Nosir; Steinberger, Yosef

    2008-01-01

    The effect of distance from a heavy metal pollution source on the soil nematode community (trophic structure, sex structure, and taxa composition) was investigated along a 15-km transect originating at the Almalyk Industrial Complex, Uzbekistan (pollution source). The soil nematode community was exposed to heavy metal influence both directly and through soil properties changes. Pollution effect on the density and biomass of soil free-living nematodes was found to be highest at pollution source, with fungivores and plant parasites dominating at the upper and deeper soil layers next to the pollution source. These groups decreased along the transect, yielding domination to bacteria- and fungi-feeders. The sex ratio of nematode communities was found to be dependent on heavy metal pollution levels, with the juveniles being the most sensitive nematode group. The Maturity and modified Maturity Indices, reflecting the degree of disturbance of the soil ecosystem, were found to be the most sensitive indices. - Trophic structure and sex ratio of soil nematode population are sensitive tools for monitoring industrial pollution

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

    Science.gov (United States)

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

    2011-08-01

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

  13. Nematode suppression and growth stimulation in corn plants (Zea mays L.) irrigated with domestic effluent.

    Science.gov (United States)

    Barros, Kenia Kelly; do Nascimento, Clístenes Williams Araújo; Florencio, Lourdinha

    2012-01-01

    Treated wastewater has great potential for agricultural use due to its concentrations of nutrients and organic matter, which are capable of improving soil characteristics. Additionally, effluents can induce suppression of plant diseases caused by soil pathogens. This study evaluates the effect of irrigation with effluent in a UASB reactor on maize (Zea mays L.) development and on suppression of the diseases caused by nematodes of the genus Meloidogyne. Twelve lysimeters of 1 m(3) each were arranged in a completely randomized design, with four treatments and three replicates. The following treatments were used: T1 (W+I), irrigation with water and infestation with nematodes; T2 (W+I+NPK), irrigation with water, infestation with nematodes and fertilization with nitrogen (N), phosphorus (P) and potassium (K); T3 (E+I), irrigation with effluent and infestation with nematodes; and T4 (E+I+P), irrigation with effluent, infestation with nematodes and fertilization with phosphorus. The plants irrigated with the effluent plus the phosphorus fertilizer had better growth and productivity and were more resistant to the disease symptoms caused by the nematodes. The suppression levels may have been due to the higher levels of Zn and NO(3)(-) found in the leaf tissue of the plants irrigated with the effluent and phosphorus fertilizer.

  14. A lover and a fighter: the genome sequence of an entomopathogenic nematode Heterorhabditis bacteriophora.

    Directory of Open Access Journals (Sweden)

    Xiaodong Bai

    Full Text Available Heterorhabditis bacteriophora are entomopathogenic nematodes that have evolved a mutualism with Photorhabdus luminescens bacteria to function as highly virulent insect pathogens. The nematode provides a safe harbor for intestinal symbionts in soil and delivers the symbiotic bacteria into the insect blood. The symbiont provides virulence and toxins, metabolites essential for nematode reproduction, and antibiotic preservation of the insect cadaver. Approximately half of the 21,250 putative protein coding genes identified in the 77 Mbp high quality draft H. bacteriophora genome sequence were novel proteins of unknown function lacking homologs in Caenorhabditis elegans or any other sequenced organisms. Similarly, 317 of the 603 predicted secreted proteins are novel with unknown function in addition to 19 putative peptidases, 9 peptidase inhibitors and 7 C-type lectins that may function in interactions with insect hosts or bacterial symbionts. The 134 proteins contained mariner transposase domains, of which there are none in C. elegans, suggesting an invasion and expansion of mariner transposons in H. bacteriophora. Fewer Kyoto Encyclopedia of Genes and Genomes Orthologies in almost all metabolic categories were detected in the genome compared with 9 other sequenced nematode genomes, which may reflect dependence on the symbiont or insect host for these functions. The H. bacteriophora genome sequence will greatly facilitate genetics, genomics and evolutionary studies to gain fundamental knowledge of nematode parasitism and mutualism. It also elevates the utility of H. bacteriophora as a bridge species between vertebrate parasitic nematodes and the C. elegans model.

  15. Prevalence of Strongylida nematodes associated with African Snail, Achatina fulica, in Valle del Cauca, Colombia

    Directory of Open Access Journals (Sweden)

    Diego Córdoba-R

    2017-09-01

    Full Text Available Objectives. To establish the presence and prevalence of Strongylida nematode parasites in Achatina fulica in the Valle del Cauca, especially of nematodes that are potentially pathogenic for humans. Materials and methods. A. fulica individuals were collected in nine cities of the Valle del Cauca, Colombia. Direct visual examination was used to identify A. fulica parasites. Nematodes were separated from tissue or collected from mucus, washed in saline solution, and fixed in a hot AFA solution. Samples were mounted in glycerine and observed under the microscope. Results. The general nematode parasite prevalence was 35% in 2013. The city with highest prevalence during 2013 was Cartago (60%, following by Buenaventura (42.9% and Cali (33%, while during 2014 were Cali (30% and Buenaventura (30%. The Strongylida nematodes registered were classified in three genera: Angiostrongylus (14.7% prevalence, Aelurostrongylus (2.6%,and Strongyluris (2.6%. The city with highest positive records of Angiostrongylus was Cali during 2014 and Aelurostrongylus was Buenaventura during 2013. Strongyluris genus was recorded only in Cali during 2013, with a prevalence of 11%. Of the nine evaluated cities, five has presence of Angiostrongylus. Conclusions. Three genera of Strongylida nematode were recorded associated with A. fulicas specimens in the Valle del Cauca during 2013 and 2014. Therefore, the role that A. fulica and native mollusk species could be playing in the life cycle of these parasites at the local level should not underestimated.

  16. Pathogen-nematode interaction: Nitrogen supply of Listeria monocytogenes during growth in Caenorhabditis elegans.

    Science.gov (United States)

    Kern, Tanja; Kutzner, Erika; Eisenreich, Wolfgang; Fuchs, Thilo M

    2016-02-01

    Listeria monocytogenes is a Gram-positive facultatively intracellular human pathogen. Due to its saprophytic lifestyle, L. monocytogenes is assumed to infect and proliferate within soil organisms such as Caenorhabditis elegans. However, little is known about the nutrient usages and metabolite fluxes in this bacterium-nematode interaction. Here, we established a nematode colonization model for L. monocytogenes and a method for the efficient separation of the pathogen from the nematodal gut. Following (15)N labelling of C. elegans and gas chromatography-mass spectrometry-based (15)N isotopologue analysis, we detected a high basal metabolic rate of the nematode, and observed a significant metabolic flux from nitrogenous compounds of the nematode to listerial proteins during proliferation of the pathogen in the worm's intestine. For comparison, we also measured the N fluxes from the gut content into listerial proteins using completely (15)N-labelled Escherichia coli OP50 as food for C. elegans. In both settings, L. monocytogenes prefers the direct incorporation of histidine, arginine and lysine over their de novo biosynthesis. Our data suggest that colonization of nematodes is a strategy of L. monocytogenes to increase its access to N-rich nutrients. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. Comparative Genomics and Transcriptomics Analyses Reveal Divergent Lifestyle Features of Nematode Endoparasitic Fungus Hirsutella minnesotensis

    Science.gov (United States)

    Lai, Yiling; Liu, Keke; Zhang, Xinyu; Zhang, Xiaoling; Li, Kuan; Wang, Niuniu; Shu, Chi; Wu, Yunpeng; Wang, Chengshu; Bushley, Kathryn E.; Xiang, Meichun; Liu, Xingzhong

    2014-01-01

    Hirsutella minnesotensis [Ophiocordycipitaceae (Hypocreales, Ascomycota)] is a dominant endoparasitic fungus by using conidia that adhere to and penetrate the secondary stage juveniles of soybean cyst nematode. Its genome was de novo sequenced and compared with five entomopathogenic fungi in the Hypocreales and three nematode-trapping fungi in the Orbiliales (Ascomycota). The genome of H. minnesotensis is 51.4 Mb and encodes 12,702 genes enriched with transposable elements up to 32%. Phylogenomic analysis revealed that H. minnesotensis was diverged from entomopathogenic fungi in Hypocreales. Genome of H. minnesotensis is similar to those of entomopathogenic fungi to have fewer genes encoding lectins for adhesion and glycoside hydrolases for cellulose degradation, but is different from those of nematode-trapping fungi to possess more genes for protein degradation, signal transduction, and secondary metabolism. Those results indicate that H. minnesotensis has evolved different mechanism for nematode endoparasitism compared with nematode-trapping fungi. Transcriptomics analyses for the time-scale parasitism revealed the upregulations of lectins, secreted proteases and the genes for biosynthesis of secondary metabolites that could be putatively involved in host surface adhesion, cuticle degradation, and host manipulation. Genome and transcriptome analyses provided comprehensive understanding of the evolution and lifestyle of nematode endoparasitism. PMID:25359922

  18. The genome, transcriptome, and proteome of the nematode Steinernema carpocapsae: evolutionary signatures of a pathogenic lifestyle.

    Science.gov (United States)

    Rougon-Cardoso, Alejandra; Flores-Ponce, Mitzi; Ramos-Aboites, Hilda Eréndira; Martínez-Guerrero, Christian Eduardo; Hao, You-Jin; Cunha, Luis; Rodríguez-Martínez, Jonathan Alejandro; Ovando-Vázquez, Cesaré; Bermúdez-Barrientos, José Roberto; Abreu-Goodger, Cei; Chavarría-Hernández, Norberto; Simões, Nelson; Montiel, Rafael

    2016-11-23

    The entomopathogenic nematode Steinernema carpocapsae has been widely used for the biological control of insect pests. It shares a symbiotic relationship with the bacterium Xenorhabdus nematophila, and is emerging as a genetic model to study symbiosis and pathogenesis. We obtained a high-quality draft of the nematode's genome comprising 84,613,633 bp in 347 scaffolds, with an N50 of 1.24 Mb. To improve annotation, we sequenced both short and long RNA and conducted shotgun proteomic analyses. S. carpocapsae shares orthologous genes with other parasitic nematodes that are absent in the free-living nematode C. elegans, it has ncRNA families that are enriched in parasites, and expresses proteins putatively associated with parasitism and pathogenesis, suggesting an active role for the nematode during the pathogenic process. Host and parasites might engage in a co-evolutionary arms-race dynamic with genes participating in their interaction showing signatures of positive selection. Our analyses indicate that the consequence of this arms race is better characterized by positive selection altering specific functions instead of just increasing the number of positively selected genes, adding a new perspective to these co-evolutionary theories. We identified a protein, ATAD-3, that suggests a relevant role for mitochondrial function in the evolution and mechanisms of nematode parasitism.

  19. Do the morphological and functional traits of free-living marine nematodes mirror taxonomical diversity?

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    Semprucci, F; Cesaroni, L; Guidi, L; Balsamo, M

    2018-04-01

    The taxonomical structure and diversity of nematode assemblages are the main attributes analyzed in ecology, but nematode adaptations to their habitats are still understudied. Accordingly, a survey on some known and other newly proposed morpho-functional traits was carried out in order to: determine if the morpho-functional diversity of nematodes mirrors their taxonomical diversity; and assess potential nematode adaptations to sediment type and hydrodynamic stress. Morpho-functional traits were investigated both singularly and together and showed significant differences related to these environmental factors. The greatest taxonomical and morpho-functional diversity was found in medium-coarse sand (M-CS) and at an intermedium energy level (IEL). The M-CS and IEL were probably richer in micro-habitats and subject to a low selective pressure, hosting nematodes with a wide range of adaptations. The mirroring of morpho-functional diversity with taxonomical diversity is crucial for the future growth of the use of nematodes in biomonitoring. This is because the study of their morpho-functional traits could reduce the level of work involved and the costs of any analyses. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Association between entomopathogenic nematodes and fungi for control of Rhipicephalus microplus (Acari: Ixodidae).

    Science.gov (United States)

    Monteiro, Caio Márcio Oliveira; Araújo, Laryssa Xavier; Matos, Renata Silva; da Silva Golo, Patrícia; Angelo, Isabele Costa; de Souza Perinotto, Wendell Marcelo; Coelho Rodrigues, Camila Aparecida; Furlong, John; Bittencourt, Vânia Rita Elias Pinheiro; Prata, Márcia Cristina Azevedo

    2013-10-01

    The aim of the study was to assess the effect of the association of entomopathogenic nematodes and fungi on Rhipicephalus microplus. The nematodes used were Heterorhabditis bacteriophora HP88 and Heterorhabditis indica LPP1 and the fungi were Metarhizium anisopliae IBCB 116 and Beauveria bassiana ESALQ 986. In the groups treated with the fungi, the females were immersed for 3 min in a conidial suspension, while in the groups treated with the nematodes, the ticks were exposed to infective juveniles. To evaluate the interaction between entomopathogens, the females were first immersed in a conidial suspension and then exposed to the nematodes. The egg mass weight and hatching percentage values of the groups treated with M. anisopliae IBCB 116 and B. bassiana ESALQ 986 in the two experiments were statistically similar (p > 0.05) to the values of the control group. In the groups treated only with nematodes, there was a significant reduction (p fungi, there was a significant reduction (p fungi alone varied from 31 to 55%. In the groups treated with nematodes associated or not with fungi, the control percentage was always greater than 90% and reached 100% in the group treated with H. bacteriophora HP88 associated with the fungus M. anisopliae IBCB 116.

  1. Nematóides do Brasil. Parte V: nematóides de mamíferos Brazillan nematodes. Part V: nematodes of mammals

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    Joaquim Júlio Vicente

    1997-01-01

    Full Text Available A survey of nematode species parasitizing Brazilian mammals is presented, with enough data to provide their specific identification. The tirst section refers to the survey ofthe species, related to 21 superfamilies, 45 families, 160 genera and 495 species that are illustrated and measurement tables are given. The second section is concerned to the catalogue ofhost mammals which includes 34 families, 176 species and their respective parasite nematodes. The identification of these helminths is achieved by means of keys to the superfamilies, families and genera. Specific determination is induced through the figures and tables as above mentioned.

  2. Soil nematode community under the non-native trees in the Botanic Garden of Petrozavodsk State University

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    Sushchuk Anna

    2016-12-01

    Full Text Available The particularities of soil nematode communities of the rhizosphere of non-native trees were studied in the Botanic Garden of Petrozavodsk State University (Republic of Karelia. Taxonomic diversity, abundance, community structure and ecological indices derived from nematode fauna analysis were used as the evaluation parameters. Nematode fauna included 51 genera, 6 of them were plant parasitic. The dominant eco-trophic group in the nematode community structure of coniferous trees was bacterial feeders; fungal feeders in most cases were observed in the second numbers. The contribution of bacterial feeders was decreased and plant parasites were increased in eco-trophic structure of nematode communities of deciduous trees in compared with coniferous trees. Analysis of ecological indices showed that the state of soil nematode communities reflects complex, structured (stable soil food web in the biocenoses with deciduous trees, and degraded (basal food web – under coniferous trees.

  3. Genetic identification of anisakid nematodes isolated from largehead hairtail (Trichiurus japonicus in Korea

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    Jeong-Ho Kim

    2016-07-01

    Full Text Available Abstract Background The nematode species belonging to genus Anisakis occur at their third larval stage in numerous marine teleost fish species worldwide and known to cause accidental human infection through the ingestion of raw or undercooked fish or squids. They may also draw the attention of consumers because of the visual impact of both alive and dead worms. Therefore, the information on their geographical distribution and clear species identification is important for epidemiological survey and further prevention of human infection. Results For identification of anisakid nematodes species isolated from largehead hairtail (Trichiurus japonicus, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP analysis of internal transcribed spacers of ribosomal DNA were conducted. Mitochondrial cytochrome c oxidase subunit 2 gene was also sequenced, and phylogenetic analysis was conducted. From the largehead hairtail (n = 9, 1259 nematodes were isolated in total. Most of the nematodes were found encapsulated throughout the viscera (56.2 %, 708/1259 or moving freely in the body cavity (41.5 %, 523/1259, and only 0.3 % (4/1259 was found in the muscles. By PCR-RFLP, three different nematode species were identified. Anisakis pegreffii was the most dominantly found (98.7 %, 1243/1259 from the largehead hairtail, occupying 98.7 % (699/708 of the nematodes in the mesenteries and 98.1 % (513/523 in the body cavity. Hybrid genotype (Anisakis simplex × A. pegreffii occupied 0.5 %, and Hysterothylacium sp. occupied 0.2 % of the nematodes isolated in this study. Conclusions The largehead hairtail may not significantly contribute accidental human infection of anisakid nematode third stage larvae because most of the nematodes were found from the viscera or body cavity, which are not consumed raw. But, a high prevalence of anisakid nematode larvae in the largehead hairtail is still in concern because they may raise food safety

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

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

    2018-01-01

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

  5. First use of soil nematode communities as bioindicator of radiation impact in the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Lecomte, C.; Bonzom, J.M.; Adam-Guillermin, C. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LECO (France); Della-Vedova, C. [Magelis, Cadenet (France); Beaugelin-Seiller, K. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LM2E (France); Gaschak, S. [Chernobyl Center for Nuclear safety, Radioactive waste and Radioecology, International Radioecology Laboratory (Ukraine); Coppin, F. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, L2BT (France); Garnier-Laplace, J. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS (France)

    2014-07-01

    The aim of the study was to assess the effects of former radioactive contamination on the structure of the nematode community in sites affected by the fallout from the Chernobyl accident that occurred on 26, April 1986. Nematodes were collected in spring 2011 from 18 forest sites of the Chernobyl Exclusion Zone (CEZ). The external gamma dose rates, measured from radiophotoluminescent dosimeters (RPL) varied from 0.2 to 22 μGy h{sup -1} between sites. In parallel, the Total dose rates (TDR) absorbed by nematodes were predicted from measured soil activity concentrations, Dose Conversion Coefficients (DCC, calculated by the EDEN software) and Soil-to-biota concentration ratios (from the ERICA tool database). Results showed that TDR were one order of magnitude above the external gamma dose rate measured from RPL. This is mainly due to the contribution of alpha ({sup 241}Am,{sup 238,239,240}Pu) and beta ({sup 90}Sr, and {sup 137}Cs) emitters in the external dose rate. The small size (in the order of mm) of nematodes promoted a high energy deposition throughout the organisms without fading, giving more weight to external dose rate induced by alpha-and beta-emitters, relatively to gamma-emitters. Analysis of the nematode community showed a majority of bacterial-, plant-, and fungal- feeder nematodes and almost none of the disturbance sensitive families whatever the level of radioactive contamination. Multiple regression analysis was used to establish relationships between ecological features (nematodes abundance and family diversity, indices of ecosystem structure and function) to the environmental characteristics (TDR and soil physico-chemical properties). No evidence was found that nematode total abundance and family diversity were impaired by the radiological contamination. However, the Nematode Channel Ratio (defining the relative abundance of bacterial- versus fungal-feeding nematodes) decreased significantly with increasing TDR suggesting that the radioactive

  6. The simplest "field" methods for extractin of nematodes from plants, wood, insects and soil, with additional description how to keep extracted nematodes alive for a long time.

    Science.gov (United States)

    Ryss, A Yu

    2017-01-01

    The simplest modification of the dynamic extraction method using cottonwool filter based on the Baermann funnel principle, is described. This modification excludes the funnel because a great share of Sticky worms attach to sloping walls of a funnel and thus do not reach the collector Eppendorf tube. But the main principle of the Baermann funnel is used, I. e. sinking down of actively moving heavy narrow bodies via wide holes of filter and thus separating the active worms from passive non-Brownian moving substrate particles, which do not pass the filter and remain above it. This principle is illustrated because it has never been described before. In the proposed modification any sloping walls in the extraction paths are excluded and thus the probability to attach sticky nemotodes to walls is also excluded; only cylindrical equipment with abrupt vertical walls is used; procedures are extremely simplified to be user-friendly for beginners: only filter (cotton pads), Eppendorf tubes, plastic glasses and narrow PVC tubing are applied. The new simplified modification allows one to collect nematodes by non-professional workers, e. g. in Polar expeditions without microscopic study of results. As an addition, an efficient method to maintain extracted nematodes alive is proposed, using the "effect of water film" in foam rubber inside the Eppendorf tube. To maintain nematodes alive during several months it is recommended to suppress bacteria via addition of 0.2-0.4% formaldehyde solution and then keep the tube with nematodes in a refrigerator.

  7. Microbiomes associated with infective stages of root-knot and lesion nematodes in soil.

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    Ahmed Elhady

    Full Text Available Endoparasitic root-knot (Meloidogyne spp. and lesion (Pratylenchus spp. nematodes cause considerable damage in agriculture. Before they invade roots to complete their life cycle, soil microbes can attach to their cuticle or surface coat and antagonize the nematode directly or by induction of host plant defenses. We investigated whether the nematode-associated microbiome in soil differs between infective stages of Meloidogyne incognita and Pratylenchus penetrans, and whether it is affected by variation in the composition of microbial communities among soils. Nematodes were incubated in suspensions of five organically and two integrated horticultural production soils, recovered by sieving and analyzed for attached bacteria and fungi after washing off loosely adhering microbes. Significant effects of the soil type and nematode species on nematode-associated fungi and bacteria were revealed as analyzed by community profiling using denaturing gradient gel electrophoresis. Attached microbes represented a small specific subset of the soil microbiome. Two organic soils had very similar bacterial and fungal community profiles, but one of them was strongly suppressive towards root-knot nematodes. They were selected for deep amplicon sequencing of bacterial 16S rRNA genes and fungal ITS. Significant differences among the microbiomes associated with the two species in both soils suggested specific surface epitopes. Among the 28 detected bacterial classes, Betaproteobacteria, Bacilli and Actinobacteria were the most abundant. The most frequently detected fungal genera were Malassezia, Aspergillus and Cladosporium. Attached microbiomes did not statistically differ between these two soils. However, Malassezia globosa and four fungal species of the family Plectosphaerellaceae, and the bacterium Neorhizobium galegae were strongly enriched on M. incognita in the suppressive soil. In conclusion, the highly specific attachment of microbes to infective stages of

  8. Interspecific competition between entomopathogenic nematodes (Steinernema is modified by their bacterial symbionts (Xenorhabdus

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    Pages Sylvie

    2006-09-01

    Full Text Available Abstract Background Symbioses between invertebrates and prokaryotes are biological systems of particular interest in order to study the evolution of mutualism. The symbioses between the entomopathogenic nematodes Steinernema and their bacterial symbiont Xenorhabdus are very tractable model systems. Previous studies demonstrated (i a highly specialized relationship between each strain of nematodes and its naturally associated bacterial strain and (ii that mutualism plays a role in several important life history traits of each partner such as access to insect host resources, dispersal and protection against various biotic and abiotic factors. The goal of the present study was to address the question of the impact of Xenorhabdus symbionts on the progression and outcome of interspecific competition between individuals belonging to different Steinernema species. For this, we monitored experimental interspecific competition between (i two nematode species: S. carpocapsae and S. scapterisci and (ii their respective symbionts: X. nematophila and X. innexi within an experimental insect-host (Galleria mellonella. Three conditions of competition between nematodes were tested: (i infection of insects with aposymbiotic IJs (i.e. without symbiont of both species (ii infection of insects with aposymbiotic IJs of both species in presence of variable proportion of their two Xenorhabdus symbionts and (iii infection of insects with symbiotic IJs (i.e. naturally associated with their symbionts of both species. Results We found that both the progression and the outcome of interspecific competition between entomopathogenic nematodes were influenced by their bacterial symbionts. Thus, the results obtained with aposymbiotic nematodes were totally opposite to those obtained with symbiotic nematodes. Moreover, the experimental introduction of different ratios of Xenorhabdus symbionts in the insect-host during competition between Steinernema modified the proportion of

  9. FLP-1 neuropeptides modulate sensory and motor circuits in the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Buntschuh, Ingrid; Raps, Daniel A; Joseph, Ivor; Reid, Christopher; Chait, Alexander; Totanes, Raubern; Sawh, Michelle; Li, Chris

    2018-01-01

    Parasitic nematodes infect over one quarter of the population worldwide, causing morbidity in over one billion people. Current anthelmintic drugs are beginning to lose effectiveness due to the presence of resistant strains. We are interested in the role of neuropeptides, which regulate behaviors in all organisms, as another possible target for anthelmintic drugs. FMRFamide-related peptides (FaRPs) are a family of neuropeptides that are conserved throughout the animal kingdom. In particular, nematodes contain the largest family of FaRPs identified thus far and many of these FaRPs are identical among different nematode species; FaRPs in nematodes are collectively referred to as FLPs (FMRFamide-like peptides). However, little is known about the function of these FLPs. We are using the non-parasitic nematode Caenorhabditis elegans as a model for examining FLPs in nematodes. C. elegans contains at least 31 flp genes that encode 72 potential FLPs. Among the flp genes, flp-1 is one of the few that is universally found in nematodes. FLP-1 neuropeptides were previously reported to be involved in sensory and motor functions. However, previous alleles of flp-1 also disrupted a neighboring gene, daf-10. To understand the phenotypes of flp-1, new alleles that specifically disrupt flp-1 were characterized. The previously reported locomotory and egg-laying defects were found to be due to loss of flp-1, while the osmolarity defect is due to loss of daf-10. In addition, loss of flp-1 and daf-10 both cause several phenotypes that increase in severity in the double mutants by disrupting different neurons in the neural circuits.

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

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    Tejashwari Meerupati

    2013-11-01

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

  11. Feeding and the rhodopsin family G-Protein Coupled Receptors (GPCRs in nematodes and arthropods

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    Joao Carlos dos Reis Cardoso

    2012-12-01

    Full Text Available In vertebrates, receptors of the rhodopsin G-protein coupled superfamily (GPCRs play an important role in the regulation of feeding and energy homeostasis and are activated by peptide hormones produced in the brain-gut axis. These peptides regulate appetite and energy expenditure by promoting or inhibiting food intake. Sequence and function homologues of human GPCRs involved in feeding exist in the nematode roundworm, Caenorhabditis elegans (C. elegans and the arthropod fruit fly, Drosophila melanogaster (D. melanogaster, suggesting that the mechanisms that regulate food intake emerged early and have been conserved during metazoan radiation. Nematodes and arthropods are the most diverse and successful animal phyla on Earth. They can survive in a vast diversity of environments and have acquired distinct life styles and feeding strategies. The aim of the present review is to investigate if this diversity has affected the evolution of invertebrate GPCRs. Homologues of the C. elegans and D. melanogaster rhodopsin receptors were characterized in the genome of other nematodes and arthropods and receptor evolution compared. With the exception of bombesin receptors (BBR that are absent from nematodes, a similar gene complement was found. In arthropods, rhodopsin GPCR evolution is characterized by species-specific gene duplications and deletions and in nematodes by gene expansions in species with a free-living stage and gene deletions in representatives of obligate parasitic taxa. Based upon variation in GPCR gene number and potentially divergent functions within phyla we hypothesize that life style and feeding diversity practiced by nematodes and arthropods was one factor that contributed to rhodopsin GPCR gene evolution. Understanding how the regulation of food intake has evolved in invertebrates will contribute to the development of novel drugs to control nematodes and arthropods and the pests and diseases that use them as vectors.

  12. Feeding and the rhodopsin family g-protein coupled receptors in nematodes and arthropods.

    Science.gov (United States)

    Cardoso, João C R; Félix, Rute C; Fonseca, Vera G; Power, Deborah M

    2012-01-01

    In vertebrates, receptors of the rhodopsin G-protein coupled superfamily (GPCRs) play an important role in the regulation of feeding and energy homeostasis and are activated by peptide hormones produced in the brain-gut axis. These peptides regulate appetite and energy expenditure by promoting or inhibiting food intake. Sequence and function homologs of human GPCRs involved in feeding exist in the nematode roundworm, Caenorhabditis elegans (C. elegans), and the arthropod fruit fly, Drosophila melanogaster (D. melanogaster), suggesting that the mechanisms that regulate food intake emerged early and have been conserved during metazoan radiation. Nematodes and arthropods are the most diverse and successful animal phyla on Earth. They can survive in a vast diversity of environments and have acquired distinct life styles and feeding strategies. The aim of the present review is to investigate if this diversity has affected the evolution of invertebrate GPCRs. Homologs of the C. elegans and D. melanogaster rhodopsin receptors were characterized in the genome of other nematodes and arthropods and receptor evolution compared. With the exception of bombesin receptors (BBR) that are absent from nematodes, a similar gene complement was found. In arthropods, rhodopsin GPCR evolution is characterized by species-specific gene duplications and deletions and in nematodes by gene expansions in species with a free-living stage and gene deletions in representatives of obligate parasitic taxa. Based upon variation in GPCR gene number and potentially divergent functions within phyla we hypothesize that life style and feeding diversity practiced by nematodes and arthropods was one factor that contributed to rhodopsin GPCR gene evolution. Understanding how the regulation of food intake has evolved in invertebrates will contribute to the development of novel drugs to control nematodes and arthropods and the pests and diseases that use them as vectors.

  13. Analysis of the Transcriptome of the Infective Stage of the Beet Cyst Nematode, H. schachtii.

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    John Fosu-Nyarko

    Full Text Available The beet cyst nematode, Heterodera schachtii, is a major root pest that significantly impacts the yield of sugar beet, brassicas and related species. There has been limited molecular characterisation of this important plant pathogen: to identify target genes for its control the transcriptome of the pre-parasitic J2 stage of H. schachtii was sequenced using Roche GS FLX. Ninety seven percent of reads (i.e., 387,668 with an average PHRED score > 22 were assembled with CAP3 and CLC Genomics Workbench into 37,345 and 47,263 contigs, respectively. The transcripts were annotated by comparing with gene and genomic sequences of other nematodes and annotated proteins on public databases. The annotated transcripts were much more similar to sequences of Heterodera glycines than to those of Globodera pallida and root knot nematodes (Meloidogyne spp.. Analysis of these transcripts showed that a subset of 2,918 transcripts was common to free-living and plant parasitic nematodes suggesting that this subset is involved in general nematode metabolism and development. A set of 148 contigs and 183 singletons encoding putative homologues of effectors previously characterised for plant parasitic nematodes were also identified: these are known to be important for parasitism of host plants during migration through tissues or feeding from cells or are thought to be involved in evasion or modulation of host defences. In addition, the presence of sequences from a nematode virus is suggested. The sequencing and annotation of this transcriptome significantly adds to the genetic data available for H. schachtii, and identifies genes primed to undertake required roles in the critical pre-parasitic and early post-parasitic J2 stages. These data provide new information for identifying potential gene targets for future protection of susceptible crops against H. schachtii.

  14. Effect of spraying Arthrobotrys conoides conidia on pastures to control nematode infection in sheep

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    Margarete Kimie Falbo

    2015-02-01

    Full Text Available The effect of spraying pastures with conidia of the fungus Arthrobotrys conoides (GenBank ID: JN191309 for the biological control of gastrointestinal nematode infection-pressure in lambs was assessed. A 12,000-m2 area was divided into six 2,000-m2 fenced areas. Two groups were formed: the treatment group comprised three fenced areas, where conidia were sprayed on the pasture weekly at 7.5 x 104 conidia m-2; and the control group, also comprising three fenced areas, where conidia were not sprayed. The pastures included lopsided oat (Avena strigosa Schreb and Italian ryegrass (Lolium multiflorum Lam.. Five naturally infected lambs, were placed between July and September in each fenced area. The effectiveness of biological control was assessed between May and September 2009 by counting the number of third-stage larvae (L3 in each pasture. Additionally, the egg output of the sentinel animals was monitored by counting the number of gastrointestinal nematode eggs per gram of faeces (EPG and the average weight gain was measured. The negative impact on soil was assessed by counting the number of free-living nematodes and phytonematodes. The number of gastrointestinal nematode larvae in the treated pastures decreased. This was significant at two examination days (end August and end of September. At the end of the study, conidia treatment reduced gastrointestinal nematodes on pasture by 52.4% compared to the control group; this difference was statistically significant. Regarding the whole examination period the average reductions in EPG in treatment group was 49.1% compared to the control group. The most common genera of gastrointestinal nematodes were Haemonchus and Trichostrongylus. Animal weight gain and soil nematode counts did not differ significantly.

  15. Conservation of MAP kinase activity and MSP genes in parthenogenetic nematodes

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    Ndifon Nsah

    2010-05-01

    Full Text Available Abstract Background MAP (mitogen-activated protein kinase activation is a prerequisite for oocyte maturation, ovulation and fertilisation in many animals. In the hermaphroditic nematode Caenorhabditis elegans, an MSP (major sperm protein dependent pathway is utilised for MAP kinase activation and successive oocyte maturation with extracellular MSP released from sperm acting as activator. How oocyte-to-embryo transition is triggered in parthenogenetic nematode species that lack sperm, is not known. Results We investigated two key elements of oocyte-to-embryo transition, MSP expression and MAP kinase signaling, in two parthenogenetic nematodes and their close hermaphroditic relatives. While activated MAP kinase is present in all analysed nematodes irrespective of the reproductive mode, MSP expression differs. In contrast to hermaphroditic or bisexual species, we do not find MSP expression at the protein level in parthenogenetic nematodes. However, genomic sequence analysis indicates that functional MSP genes are present in several parthenogenetic species. Conclusions We present three alternative interpretations to explain our findings. (1 MSP has lost its function as a trigger of MAP kinase activation and is not expressed in parthenogenetic nematodes. Activation of the MAP kinase pathway is achieved by another, unknown mechanism. Functional MSP genes are required for occasionally emerging males found in some parthenogenetic species. (2 Because of long-term disadvantages, parthenogenesis is of recent origin. MSP genes remained intact during this short intervall although they are useless. As in the first scenario, an unknown mechanism is responsible for MAP kinase activation. (3 The molecular machinery regulating oocyte-to-embryo transition in parthenogenetic nematodes is conserved with respect to C. elegans, thus requiring intact MSP genes. However, MSP expression has been shifted to non-sperm cells and is reduced below the detection limits, but is

  16. Efficacy of entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) on developmental stages of house fly, Musca domestica.

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    Archana, M; D'Souza, Placid E; Patil, Jagadeesh

    2017-09-01

    The housefly, Musca domestica is a major domestic, medical and veterinary pest. The management of these flies reliance on insecticide, causes environmental constraints, insecticide resistance and residues in the meat, skin. Therefore one of the eco-friendly alternate methods is by using biological agents such as entomopathogenic nematodes (EPN). In the present study evaluated the survival of EPN species Steinernema feltiae , Heterorhabditis indica , S. carpocapsae , S. glaseri and S. abbasi in poultry manure and also their efficacy against different developmental stages of house fly. After exposing to poultry manure, S. feltiae showed more survival as followed by H. indica , S. carpocapsae , S. glaseri and S. abbasi in all exposition period. When the exposition period extended to 96 h, all nematode species survivability was drastically reduced. After exposing these nematodes to poultry manure at 24 h their virulence capacity against wax moth, Galleria mellonella showed all the nematode species were able cause 100% mortality. However their progeny production was significantly reduced. Fly eggs and pupae were refractory to these nematode infection. Petri dish without artificial diet assay showed that, second and 3rd-instar larvae were highly susceptible to EPNs as compared to larvae provided with artificial diet. H. indica showed high virulence capacity compared to other nematodes tested. Poultry manure assay revealed that, H. indica and S. carpocapsae caused minimal mortality where as S. feltiae , S. glaseri and S. abbasi did not cause any mortality. This may be because of poor survival and limited movement of nematodes in poultry manure which may be due to ammonia, other toxic substances in poultry manure. The decrease in larval mortality in manure suggests that biocontrol of housefly by using EPNs is unlikely.

  17. Analysis of the Transcriptome of the Infective Stage of the Beet Cyst Nematode, H. schachtii.

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    Fosu-Nyarko, John; Nicol, Paul; Naz, Fareeha; Gill, Reetinder; Jones, Michael G K

    2016-01-01

    The beet cyst nematode, Heterodera schachtii, is a major root pest that significantly impacts the yield of sugar beet, brassicas and related species. There has been limited molecular characterisation of this important plant pathogen: to identify target genes for its control the transcriptome of the pre-parasitic J2 stage of H. schachtii was sequenced using Roche GS FLX. Ninety seven percent of reads (i.e., 387,668) with an average PHRED score > 22 were assembled with CAP3 and CLC Genomics Workbench into 37,345 and 47,263 contigs, respectively. The transcripts were annotated by comparing with gene and genomic sequences of other nematodes and annotated proteins on public databases. The annotated transcripts were much more similar to sequences of Heterodera glycines than to those of Globodera pallida and root knot nematodes (Meloidogyne spp.). Analysis of these transcripts showed that a subset of 2,918 transcripts was common to free-living and plant parasitic nematodes suggesting that this subset is involved in general nematode metabolism and development. A set of 148 contigs and 183 singletons encoding putative homologues of effectors previously characterised for plant parasitic nematodes were also identified: these are known to be important for parasitism of host plants during migration through tissues or feeding from cells or are thought to be involved in evasion or modulation of host defences. In addition, the presence of sequences from a nematode virus is suggested. The sequencing and annotation of this transcriptome significantly adds to the genetic data available for H. schachtii, and identifies genes primed to undertake required roles in the critical pre-parasitic and early post-parasitic J2 stages. These data provide new information for identifying potential gene targets for future protection of susceptible crops against H. schachtii.

  18. Transcriptome analysis of resistant and susceptible alfalfa cultivars infected with root-knot nematode Meloidogyne incognita.

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    Olga A Postnikova

    Full Text Available Nematodes are one of the major limiting factors in alfalfa production. Root-knot nematodes (RKN, Meloidogyne spp. are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to alfalfa fields. As of today, no studies have been published on global gene expression profiling in alfalfa infected with RKN or any other plant parasitic nematode. Very little information is available about molecular mechanisms that contribute to pathogenesis and defense responses in alfalfa against these pests and specifically against RKN. In this work, we performed root transcriptome analysis of resistant (cv. Moapa 69 and susceptible (cv. Lahontan alfalfa cultivars infected with RKN Meloidogyne incognita, widespread root-knot nematode species and a major pest worldwide. A total of 1,701,622,580 pair-end reads were generated on an Illumina Hi-Seq 2000 platform from the roots of both cultivars and assembled into 45,595 and 47,590 transcripts in cvs Moapa 69 and Lahontan, respectively. Bioinformatic analysis revealed a number of common and unique genes that were differentially expressed in susceptible and resistant lines as a result of nematode infection. Although the susceptible cultivar showed a more pronounced defense response to the infection, feeding sites were successfully established in its roots. Characteristically, basal gene expression levels under normal conditions differed between the two cultivars as well, which may confer advantage to one of the genotypes toward resistance to nematodes. Differentially expressed genes were subsequently assigned to known Gene Ontology categories to predict their functional roles and associated biological processes. Real-time PCR validated expression changes in genes arbitrarily selected for experimental confirmation. Candidate genes that contribute to protection against M. incognita in alfalfa were proposed and alfalfa-nematode interactions with

  19. Transcriptome analysis of resistant and susceptible alfalfa cultivars infected with root-knot nematode Meloidogyne incognita.

    Science.gov (United States)

    Postnikova, Olga A; Hult, Maria; Shao, Jonathan; Skantar, Andrea; Nemchinov, Lev G

    2015-01-01

    Nematodes are one of the major limiting factors in alfalfa production. Root-knot nematodes (RKN, Meloidogyne spp.) are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to alfalfa fields. As of today, no studies have been published on global gene expression profiling in alfalfa infected with RKN or any other plant parasitic nematode. Very little information is available about molecular mechanisms that contribute to pathogenesis and defense responses in alfalfa against these pests and specifically against RKN. In this work, we performed root transcriptome analysis of resistant (cv. Moapa 69) and susceptible (cv. Lahontan) alfalfa cultivars infected with RKN Meloidogyne incognita, widespread root-knot nematode species and a major pest worldwide. A total of 1,701,622,580 pair-end reads were generated on an Illumina Hi-Seq 2000 platform from the roots of both cultivars and assembled into 45,595 and 47,590 transcripts in cvs Moapa 69 and Lahontan, respectively. Bioinformatic analysis revealed a number of common and unique genes that were differentially expressed in susceptible and resistant lines as a result of nematode infection. Although the susceptible cultivar showed a more pronounced defense response to the infection, feeding sites were successfully established in its roots. Characteristically, basal gene expression levels under normal conditions differed between the two cultivars as well, which may confer advantage to one of the genotypes toward resistance to nematodes. Differentially expressed genes were subsequently assigned to known Gene Ontology categories to predict their functional roles and associated biological processes. Real-time PCR validated expression changes in genes arbitrarily selected for experimental confirmation. Candidate genes that contribute to protection against M. incognita in alfalfa were proposed and alfalfa-nematode interactions with respect to resistance

  20. Nematode pests threatening soybean production in South Africa, with reference to Meloidogyne

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    Hendrika Fourie

    2015-09-01

    Full Text Available The area planted to soybean in South Africa has increased by 54% since the 2009 growing season, mainly as a result of the increasing demand for protein-rich food and fodder sources. Moreover, the introduction of advanced technology, namely the availability of genetically modified herbicide tolerant soybean cultivars also contributed towards increased soybean production. The omnipresence of plant-parasitic nematodes in local agricultural soils, however, poses a threat to the sustainable expansion and production of soybean and other rotation crops. Meloidogyne incognita and M. javanica are the predominant nematode pests in local soybean production areas and those where other grain-, legume- and/or vegetable crops are grown. The lack of registered nematicides for soybean locally, crop production systems that are conducive to nematode pest build-ups as well as the limited availability of genetic host plant resistance to root-knot nematode pests, complicate their management. Research aimed at various aspects related to soybean-nematode research, namely, audits of nematode assemblages associated with the crop, identification of genetic host plant resistance in soybean germplasm to M. incognita and M. javanica, the use of molecular markers that are linked to such genetic resistance traits as well as agronomic performance of pre-released cultivars that can be valuable to producers and the industry are accentuated in this review. Evaluation of synthetically-derived as well as biological-control agents are also discussed as complementary management tactics. It is important that lessons learned through extensive research on soybean-nematode interactions in South Africa be shared with researchers and industries in other countries as they might experience or expect similar problems and/or challenges.

  1. Windstorms as mediator of soil nematode community changes: Evidence from European spruce forest

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    Renčo M.

    2017-03-01

    Full Text Available Nematode communities in a Norway spruce forest in High Tatra National Park, Slovakia were monitored for the period of several years (2006 and 2013. Unfortunately, in May 2014 natural windstorm damaged the forest. This disastrous event, together with preliminary obtained results allowed us to compare the direct impact of windstorm damage of forest habitat on soil nematode assemblages. The forest destruction by windstorm had a significant effect on the total nematode abundance, the abundance of omnivores and herbivores, as well as the nematode species diversity. The most dominant species, representing 55 % of the total nematode fauna, in the plot studied were Acrobeloides nanus followed by Malenchus exiguus, Filenchus vulgaris, Plectus communis, Plectus parvus and Tylencholaimus mirabilis. The abundance of bacterivorous signifi cantly increased after the windstorm, meanwhile the abundance of omnivores, fungivores, and herbivores ectoparasites and epidermal/root hair feeders showed an opposite trend. Of the evaluative indicators, Shannon species diversity (H’spp, maturity index (MI, maturity index 2-5 (MI2-5, sigma maturity index (ΣMI, enrichment index (EI and structure index (SI decreased significantly after windstorm. The EI and SI indexes characterized soil ecosystems before windstorm (2006 - 2013 as maturing with low or moderate disturbance, but soil ecosystems shortly after the windstorm (2014 were degraded and nutrient depleted. This also corresponded with graphical display of metabolic footprints characteristics of soil food web. Overall, the nematode communities differed significantly before and after forest damage. These results suggest the role of nematode communities as indicators of environment condition quality or its disruption.

  2. Artificial dirt: microfluidic substrates for nematode neurobiology and behavior.

    Science.gov (United States)

    Lockery, S R; Lawton, K J; Doll, J C; Faumont, S; Coulthard, S M; Thiele, T R; Chronis, N; McCormick, K E; Goodman, M B; Pruitt, B L

    2008-06-01

    With a nervous system of only 302 neurons, the free-living nematode Caenorhabditis elegans is a powerful experimental organism for neurobiology. However, the laboratory substrate commonly used in C. elegans research, a planar agarose surface, fails to reflect the complexity of this organism's natural environment, complicates stimulus delivery, and is incompatible with high-resolution optophysiology experiments. Here we present a new class of microfluidic devices for C. elegans neurobiology and behavior: agarose-free, micron-scale chambers and channels that allow the animals to crawl as they would on agarose. One such device mimics a moist soil matrix and facilitates rapid delivery of fluid-borne stimuli. A second device consists of sinusoidal channels that can be used to regulate the waveform and trajectory of crawling worms. Both devices are thin and transparent, rendering them compatible with high-resolution microscope objectives for neuronal imaging and optical recording. Together, the new devices are likely to accelerate studies of the neuronal basis of behavior in C. elegans.

  3. Ultraestructural study of effects of alkylphospholipid analogs against nematodes.

    Science.gov (United States)

    Sant' Anna, Viviane; Railbolt, Marcelle; Oliveira-Menezes, Aleksandra; Calogeropoulou, Theodora; Pinheiro, Jairo; de Souza, Wanderley

    2018-02-26

    Alkylphospholipid analogs were initially developed as anticancer agents and were later found to antiparasitic activity. Miltefosine is the prototype alkylphosphocholine and is the first oral treatment against visceral leishmaniasis. Here we investigated the effects of miltefosine and two ring-substituted alkylphosphocholine derivatives, TCAN26 and TC70, on the viability, morphology, and ultrastructure of the life stages of Caenorhabditis elegans and infective larvae of the parasite Strongyloides venezuelensis. Miltefosine displayed activity against C. elegans adults at low concentrations and was more effective than TCAN26 and TC70. Miltefosine inhibited the hatching of eggs, leading to embryonic lethality, and showed larvicidal activity against C. elegans and S. venezuelensis larvae after 24 h. Mitelfosine also induced alterations in the reproductive system of hermaphrodites, causing vulvar prolapse and general effects in the body wall. Electron microscopy analysis showed that miltefosine induced selective embryonic lethality, leading to cell death. Our results suggest that alkylphospholipid analogs are a potential new alternative for anti-nematode chemotherapy. Copyright © 2018. Published by Elsevier Inc.

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

    Science.gov (United States)

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

    2014-03-01

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

  5. Increased competitiveness of nematode sperm bearing the male X chromosome.

    Science.gov (United States)

    LaMunyon, C W; Ward, S

    1997-01-07

    Male offspring, which cannot reproduce independently, represent a cost of sexual reproduction. This cost is eliminated by the production of hermaphroditic offspring in the self-fertilizing nematode Caenorhabditis briggsae. However, these hermaphrodites can outcross by mating with males. Half the sperm received from males contain no sex chromosome and therefore give rise to male progeny. Mating with males should thus impose the cost of making male offspring. We found that male sperm took immediate precedence over hermaphrodite sperm, resulting in maximized outcrossing, but the appearance of male progeny was delayed after mating. This delay is caused by the male X-bearing sperm outcompeting their nullo-X counterparts. The competitive advantage of X-bearing sperm over nullo-X sperm is limited to sperm from males; it did not occur in a mutant hermaphrodite that produces both types of sperm. The chromosomal effect on sperm competitiveness in C. briggsae, which has not been observed in other species, suggests that the X chromosome has evolved a form of meiotic drive, selfishly increasing the competitiveness of sperm that bear it over those that do not. Thus, the multiple levels of sperm competitiveness found in C. briggsae maximize outcrossing after mating while delaying the cost of making male offspring.

  6. Epidemiology, sero-diagnosis and therapeutic studies on nematodes infection in balochi range-sheep at district quetta, balochistan, pakistan.

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    Abdul Razzaq

    2014-06-01

    Full Text Available Among the infectious organisms of parasitic origin, gastrointestinal nematodes are very important as they have been reported worldwide. The main aim of the present research study to highlight the annual epidemiological contributing factors associated with the prevalence of gastrointestinal nematodes and their control in sheep.A total 1200 faecal samples (100 per month were collected from farmers holding Balochi-sheep (either sexes, 1-5 years old during January-December 2012 and analyzed to determine the prevalence of nematodes based on microscopy and ELISA based diagnostic assay. Therapeutic efficacies of different synthetic and herbal medicines against these nematodes were assessed by field trials.Results showed that 23.92% Balochi-sheep were infected with nematodes. Five nematodes infections were recorded with highest prevalence of Haemonchus (7.75% followed by Nematodirus (7.58%, Strongyloides (4.42%, Trichostrongylus (2.33% and Trichuris (1.83%. The younger and older ewes (one and five years presented higher nematodes prevalence with peak during March/April and August/September. Haemonchus and Trichuris positive samples based on coprological examination were also showed 92-100% positive sensitivity for these nematodes by the ELISA. Sheep treated with Ivermectin showed higher reduction (97.76% in nematode egg counts followed by Atreefal deedan (96.42% and Oxfendazole (95.44%, respectively.The gastro-intestinal nematodes are prevalent in all age and either sex of Balochi-sheep with peak during summer. The ELISA based diagnosis is more accurte. The synthetic and herbal products are very effective against sheep nematodes.

  7. Spatial and temporal variation of intertidal nematodes in the northern Gulf of Mexico after the Deepwater Horizon oil spill.

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    Brannock, Pamela M; Sharma, Jyotsna; Bik, Holly M; Thomas, W Kelley; Halanych, Kenneth M

    2017-09-01

    Nematodes are an abundant and diverse interstitial component of sedimentary habitats that have been reported to serve as important bioindicators. Though the 2010 Deepwater Horizon (DWH) disaster occurred 60 km offshore in the Gulf of Mexico (GOM) at a depth of 1525 m, oil rose to the surface and washed ashore, subjecting large segments of coastline in the northern GOM to contamination. Previous metabarcoding work shows intertidal nematode communities were negatively affected by the oil spill. Here we examine the subsequent recovery of nematode community structure at five sites along the Alabama coast over a two-year period. The latter part of the study (July 2011-July 2012) also included an examination of nematode vertical distribution in intertidal sediments. Results showed nematode composition within this region was more influenced by sample locality than time and depth. The five sampling sites were characterized by distinct nematode assemblages that varied by sampling dates. Nematode diversity decreased four months after the oil spill but increased after one year, returning to previous levels at all sites except Bayfront Park (BP). There was no significant difference among nematode assemblages in reference to vertical distribution. Although the composition of nematode assemblages changed, the feeding guilds they represented were not significantly different even though some variation was noted. Data from morphological observations integrated with metabarcoding data indicated similar spatial variation in nematode distribution patterns, indicating the potential of using these faster approaches to examine overall disturbance impact trends within communities. Heterogeneity of microhabitats in the intertidal zone indicates that future sampling and fine-scale studies of nematodes are needed to examine such anthropogenic effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Spatial distribution of nematodes in soil cultivated with sugarcane under different uses

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    Cardoso, M. O.; Pedrosa, E. M. R.; Vicente, T. F. S.; Siqueira, G. M.; Montenegro, A. A. A.

    2012-04-01

    Sugarcane is a crop of major importance within the Brazilian economy, being an activity that generates energy and with high capacity to develop various economic sectors. Currently the greatest challenge is to maximize productivity and minimize environmental impacts. The plant-parasites nematodes have great expression, because influence directly the productive potential of sugarcane crops. Accordingly, little research has been devoted to the study of spatial variability of nematodes. Thus, the purpose of this work is to analyze the spatial distribution of nematodes in a soil cultivated with sugarcane in areas with and without irrigation, with distinct spacing of sampling to determine the differences between the sampling scales. The study area is located in the municipality of Goiana (Pernambuco State, Brazil). The experiment was conducted in two areas with 40 hectares each, being collected 90 samples at different spacing: 18 samples with spacing of 200.00 x 200.00 m, 36 samples with spacing of 20.00 m x 20.00 m and 36 samples with spacing of 2.00 m x 2.00 m. Soil samples were collected at deep of 0.00-0.20 m and nematodes were extracted per 300 cm3 of soil through centrifugal flotation in sucrose being quantified, classified according trophic habit (plant-parasites, fungivores, bacterivores, omnivores and predators) and identified in level of genus or family. In irrigated area the amount of water applied was determined considering the evapotranspiration of culture. The data were analyzed using classical statistics and geostatistics. The results demonstrated that the data showed high values of coefficient of variation in both study areas. All attributes studied showed log normal frequency distribution. The area B (irrigated) has a population of nematodes more stable than the area A (non-irrigated), a fact confirmed by its mean value of the total population of nematodes (282.45 individuals). The use of geostatistics not allowed to assess the spatial distribution of

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

    Science.gov (United States)

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

    2011-01-01

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

  10. Earthworms and Plant Residues Modify Nematodes in Tropical Cropping Soils (Madagascar): A Mesocosm Experiment

    International Nuclear Information System (INIS)

    Villenave, C.; Kichenin, E.; Djigal, D.; Blanchart, E.; Rabary, B.; Djigal, D.

    2010-01-01

    Free-living nematodes present several characteristics that have led to their use as bio indicators of soil quality. Analyzing the structure of nematofauna is a pertinent way to understand soil biological processes. Earthworms play an important role in soil biological functioning and organic matter dynamics. Their effects on soil nematofauna have seldom been studied. We studied the effect of the tropical endogeic earthworm, Pontoscolex corethrurus, on nematode community structure in a 5-month field mesocosm experiment conducted in Madagascar. Ten different treatments with or without earthworms and with or without organic residues (rice, soybean) were compared. Organic residues were applied on the soil surface or mixed with the soil. The abundance of nematodes (bacterial and fungal feeders) was higher in presence of P. corethrurus than in their absence. The type of plant residues as well as their localisation had significant effects on the abundance and composition of soil nematodes. The analysis of nematode community structure showed that earthworm activity led to an overall activation of the microbial compartment without specific stimulation of the bacterial or fungal compartment.

  11. Earthworms and Plant Residues Modify Nematodes in Tropical Cropping Soils (Madagascar: A Mesocosm Experiment

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    Cécile Villenave

    2010-01-01

    Full Text Available Free-living nematodes present several characteristics that have led to their use as bioindicators of soil quality. Analyzing the structure of nematofauna is a pertinent way to understand soil biological processes. Earthworms play an important role in soil biological functioning and organic matter dynamics. Their effects on soil nematofauna have seldom been studied. We studied the effect of the tropical endogeic earthworm, Pontoscolex corethrurus, on nematode community structure in a 5-month field mesocosm experiment conducted in Madagascar. Ten different treatments with or without earthworms and with or without organic residues (rice, soybean were compared. Organic residues were applied on the soil surface or mixed with the soil. The abundance of nematodes (bacterial and fungal feeders was higher in presence of P. corethrurus than in their absence. The type of plant residues as well as their localisation had significant effects on the abundance and composition of soil nematodes. The analysis of nematode community structure showed that earthworm activity led to an overall activation of the microbial compartment without specific stimulation of the bacterial or fungal compartment.

  12. Field efficacy against the hazelnut weevil, Curculio nucum and short-term persistence of entomopathogenic nematodes

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    L. Batalla-Carrera

    2013-11-01

    Full Text Available The hazelnut weevil, Curculio nucum L. (Coleoptera: Curculionidae is a pest affecting hazelnut orchards in Europe, with an important economical repercussion. Its potential control, short-term field persistence and the vertical distribution of native entomopathogenic nematode strains were tested in Muntanyes de Prades, Tarragona (NE Iberian Peninsula over two consecutive years. Steinernema feltiae strain D114, Steinernema sp. strain D122 and Heterorhabditis bacteriophora strain DG46 were used in summer and spring applications at a dosage of 5·105 IJs m-2. The three nematode species reduced the hazelnut weevil population, ranging from 32% to 88% efficacy, without significant differences in efficacy or between the two applications. Persistence evaluation was carried out during 9 weeks for S. feltiae (D114, Steinernema sp. (D122 and H. bacteriophora (DG46 and showed all species capable of lasting for this period. Nematodes and larval vertical distribution was assessed. Most of the hazelnut weevil stayed within the first 25 cm although some were found as deep as 40 cm. Entomopathogenic nematodes were found along all 40 cm depth. This study proves the suitability of entomopathogenic nematodes to control the hazelnut weevil.

  13. Impact of castor meal on root-knot and free-living nematodes

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    Cecilia Helena Silvino Prata Ritzinger

    2014-08-01

    Full Text Available Soil amendment may enhance soil quality as well as reduce plant-parasitic nematode. Despite the many applications already undertaken using castor meal, its efficiency in controlling root-knot nematodes (RKN, Meloidogyne incognita when applied to melon (Cucumis melo is still not clear. Three different amounts of castor meal (Ricinus communis applied were evaluated in microplots planted with melon either with or without RKN. The impact of castor meal on soil free-living nematode communities was also determined. Total nematode genera richness was estimated as 37 for the entire set of microplots sampled across both sampling dates. Rarefaction analysis resulted in 12 collector's curves out of the total of 30 that reached the horizontal asymptote. Univariate ANOVA with two factors yielded differences (p < 0.05 only with regard to the time factor. Simpson, Shannon, Evenness and Equitability indices showed a trend toward moderate increases by the end of the experiment, while the other indices were higher for tomato in pre-transplant sampling compared to harvest. Nematode community and diversity changed during the course of the experiment, although there was substantial confounding heterogeneity within and between the factorial combinations from the beginning. Root knot population was not reduced by the castor meal but increased throughout the period, regardless of treatment. RKN reduced melon yield, number and weight of melon.

  14. A review of the epidemiology and control of gastrointestinal nematode infections in cattle in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Davies M. Pfukenyi

    2013-08-01

    Full Text Available In this review, the main gastrointestinal nematodes infecting cattle in Zimbabwe and the epidemiological factors influencing their occurrence are reviewed and discussed. Nineteen gastrointestinal nematode species that belong to seven families have been found to occur in cattle in Zimbabwe. The main genera reported to date are Cooperia, Haemonchus, Trichostrongylus and Oesophagostomumand the dominant species are Cooperia pectinata, Cooperia punctata, Haemonchus placei and Trichostrongylus axei. The mixed infection by several species from the genera is the cause of parasitic gastroenteritis in cattle in Zimbabwe. Production and husbandry practices, season, host age and environment are considered to be the main factors that influence gastrointestinal nematode infection in cattle. The geographical distribution of the gastrointestinal nematodes is also reviewed in relation to the climatic conditions of the country. Various control options are discussed and how they are applicable to the Zimbabwean situation. Based on reports and existing data on the epidemiological features of the gastrointestinal nematode infection in cattle, practical control measures are critically reviewed and recommendations are made for a national control programme.

  15. Prevalence and intensity of infection with gastrointestinal nematodes in sheep in eastern Serbia

    Directory of Open Access Journals (Sweden)

    Kulišić Z.

    2013-01-01

    Full Text Available A coprological examination of 680 grazing sheep was performed in Eastern Serbia from March 2011 to November 2012 in order to determine the presence of gastrointestinal (GI nematode parasites. Fecal samples were randomly collected and examined by using qualitative and quantitative coprological techniques. It was found that 74.56% sheep were infected. Samples that contained nematode eggs were processed for larval development and eleven nematode genera were identified: Haemonchus (46.91%, Ostertagia (25.88%, Marshallagia (21.91%, Cooperia (14.12%, Trichostrongylus (39.85%, Nematodirus (35.88%, Bunostomum (23.97%, Strongyloides (17.06% Oesophagostomum (40.73%, Chabertia (32.79% and Trichuris (10.88%. Higher prevalence of infection was observed in females (p<0.01, as well as in adults (p<0.001. Regarding the intensity of infection, in 40.63% sheep it was low, in 51.87% moderate and in 7.50% high. There was no difference in intensity of infection considering sex and age of animals. Moreover, simultaneous infection with different number of nematode genera was dependent on sheep’s age (p<0.001. These results suggest that GI nematodes are a conspicuous problem of grazing sheep in the study area. [Projekat Ministarstva nauke Republike Srbije, br. III 046002

  16. Orsay, Santeuil and Le Blanc viruses primarily infect intestinal cells in Caenorhabditis nematodes.

    Science.gov (United States)

    Franz, Carl J; Renshaw, Hilary; Frezal, Lise; Jiang, Yanfang; Félix, Marie-Anne; Wang, David

    2014-01-05

    The discoveries of Orsay, Santeuil and Le Blanc viruses, three viruses infecting either Caenorhabditis elegans or its relative Caenorhabditis briggsae, enable the study of virus-host interactions using natural pathogens of these two well-established model organisms. We characterized the tissue tropism of infection in Caenorhabditis nematodes by these viruses. Using immunofluorescence assays targeting proteins from each of the viruses, and in situ hybridization, we demonstrate viral proteins and RNAs localize to intestinal cells in larval stage Caenorhabditis nematodes. Viral proteins were detected in one to six of the 20 intestinal cells present in Caenorhabditis nematodes. In Orsay virus-infected C. elegans, viral proteins were detected as early as 6h post-infection. The RNA-dependent RNA polymerase and capsid proteins of Orsay virus exhibited different subcellular localization patterns. Collectively, these observations provide the first experimental insights into viral protein expression in any nematode host, and broaden our understanding of viral infection in Caenorhabditis nematodes. © 2013 Elsevier Inc. All rights reserved.

  17. USE OF NEMATODE DESTROYING FUNGI AS INDICATORS OF LAND DISTURBANCE IN TAITA TAVETA, KENYA

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    Peter Wachira

    2009-10-01

    Full Text Available This study was undertaken to determine whether nematode destroying fungi can be used as indicators of soil disturbances. Soil samples were collected from an indigenous forest, maize/bean, napier grass, shrub and vegetable fields, which represented the main land use types in Taita Taveta district of Kenya. The fungal isolates obtained were grouped into seven genera. The species identified were, Acrostalagums obovatus, Arthrobotrys dactyloides, Arthrobotrys oligospora, Arthrobotrys superba, Dactyllela lobata, Haptoglosa heterospora, Harposporium anguillulae, Harposporium.sp, Monacrosporium cionopagum and Nematoctonous georgenious. Occurrence of nematode destroying fungi was significantly (P = 3.81 x 10 -7 different among the land use systems in the study area. Out of the isolates that were positively identified, 33.7 %, 27.9 %, 20.9 %, 11.6 % and 5.8 % were from fields under vegetable, maize/bean, napier grass, shrub and forest, respectively. Soil disturbance accounted for the highest occurrence of nematode destroying fungi (60.77 % of the two main factors in the principal component analysis. While moisture, the second factor accounted for 23.35%. Fungal isolates from vegetable gardens were most diverse but the least even while the forest land use was most even but least diverse. The total richness of nematode destroying fungi was nine, in vegetable and maize/bean fields while was seven, six, and three in napier, shrub and forest habitats respectively in their decreasing order of disturbance. This study has established that nematode destroying fungi increases with increased land disturbance.

  18. Combined analyses of bacterial, fungal and nematode communities in andosolic agricultural soils in Japan.

    Science.gov (United States)

    Bao, Zhihua; Ikunaga, Yoko; Matsushita, Yuko; Morimoto, Sho; Takada-Hoshino, Yuko; Okada, Hiroaki; Oba, Hirosuke; Takemoto, Shuhei; Niwa, Shigeru; Ohigashi, Kentaro; Suzuki, Chika; Nagaoka, Kazunari; Takenaka, Makoto; Urashima, Yasufumi; Sekiguchi, Hiroyuki; Kushida, Atsuhiko; Toyota, Koki; Saito, Masanori; Tsushima, Seiya

    2012-01-01

    We simultaneously examined the bacteria, fungi and nematode communities in Andosols from four agro-geographical sites in Japan using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and statistical analyses to test the effects of environmental factors including soil properties on these communities depending on geographical sites. Statistical analyses such as Principal component analysis (PCA) and Redundancy analysis (RDA) revealed that the compositions of the three soil biota communities were strongly affected by geographical sites, which were in turn strongly associated with soil characteristics such as total C (TC), total N (TN), C/N ratio and annual mean soil temperature (ST). In particular, the TC, TN and C/N ratio had stronger effects on bacterial and fungal communities than on the nematode community. Additionally, two-way cluster analysis using the combined DGGE profile also indicated that all soil samples were classified into four clusters corresponding to the four sites, showing high site specificity of soil samples, and all DNA bands were classified into four clusters, showing the coexistence of specific DGGE bands of bacteria, fungi and nematodes in Andosol fields. The results of this study suggest that geography relative to soil properties has a simultaneous impact on soil microbial and nematode community compositions. This is the first combined profile analysis of bacteria, fungi and nematodes at different sites with agricultural Andosols.

  19. Meiofauna and nematode diversity in some Mediterranean subtidal areas of the Adriatic and Ionian Sea

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    Cristiana de Leonardis

    2008-03-01

    Full Text Available Sediments of three different subtidal areas (15-705 m depth of the Italian coasts (Manfredonia, Brindisi and Gallipoli were investigated to study meiofauna and nematode composition. The nematodes were identified to the genus level and their abundances compared using multivariate analysis. Our data showed an evident depth gradient in meiofauna abundance: the shallowest sites had more diverse and abundant meiobenthic communities than the deeper ones. Nematodes were the dominant taxon (83-100% at all sites, followed by Copepoda (0.5-8%. Sabatieria, Astomonema, Dorylaimopsis, Terschellingia and Daptonema were among the dominant nematode genera in the three areas. Nematode genus H’ diversities were not significantly dissimilar, though at community level some differences were detected among the study areas. The greatest differences were observed in the comparison of the communities from Manfredonia and Gallipoli. Furthermore, there was a difference between shallow (<200 m and deep sites due to high differential abundances of common genera, i.e. Astomonema, Dorylaimopsis, Sabatieria and Terschellingia.

  20. The diversity and evolution of nematodes (Pharyngodonidae) infecting New Zealand lizards.

    Science.gov (United States)

    Mockett, Sarah; Bell, Trent; Poulin, Robert; Jorge, Fátima

    2017-04-01

    Host-parasite co-evolutionary studies can shed light on diversity and the processes that shape it. Molecular methods have proven to be an indispensable tool in this task, often uncovering unseen diversity. This study used two nuclear markers (18S rRNA and 28S rRNA) and one mitochondrial (cytochrome oxidase subunit I) marker to investigate the diversity of nematodes of the family Pharyngodonidae parasitizing New Zealand (NZ) lizards (lygosomine skinks and diplodactylid geckos) and to explore their co-evolutionary history. A Bayesian approach was used to infer phylogenetic relationships of the parasitic nematodes. Analyses revealed that nematodes parasitizing skinks, currently classified as Skrjabinodon, are more closely related to Spauligodon than to Skrjabinodon infecting NZ geckos. Genetic analyses also uncovered previously undetected diversity within NZ gecko nematodes and provided evidence for several provisionally cryptic species. We also examined the level of host-parasite phylogenetic congruence using a global-fit approach. Significant congruence was detected between gecko-Skrjabinodon phylogenies, but our results indicated that strict co-speciation is not the main co-evolutionary process shaping the associations between NZ skinks and geckos and their parasitic nematodes. However, further sampling is required to fully resolve co-phylogenetic patterns of diversification in this host-parasite system.

  1. Agrobacteria Enhance Plant Defense Against Root-Knot Nematodes on Tomato.

    Science.gov (United States)

    Lamovšek, Janja; Stare, Barbara Gerič; Pleško, Irena Mavrič; Širca, Saša; Urek, Gregor

    2017-06-01

    The increased incidence of the crown gall disease caused by Agrobacterium tumefaciens has long been associated with activities of root-knot nematodes (Meloidogyne spp.). Pot experiments on tomato were designed to assess plant vitality, nematode reproduction, and crown gall incidence in combined infection with Agrobacterium and Meloidogyne spp. on tomato roots. Results suggest that tomato plants infected with pathogenic A. tumefaciens 2 days before the nematodes show enhanced plant defense against M. ethiopica resulting in lower egg and gall counts on roots 45 and 90 days postinoculation (dpi); no significantly enhanced defense was observed when the plant was inoculated with bacteria and nematodes at the same time. Split-root experiments also showed that the observed interaction was systemic. Reverse-transcription quantitative polymerase chain reaction analysis that targeted several genes under plant hormonal control suggests that the suppression was mediated via systemic acquired resistance by the pathogenesis-related protein 1 and that M. ethiopica did not enhance the defense reaction of tomato against Agrobacterium spp. Nematodes completely inhibited tumor growth in a 45-day experiment if inoculated onto the roots before the pathogenic bacteria. We conclude that the observed antagonism in the tested pathosystem was the result of initially strong plant defense that was later suppressed by the invading pathogen and pest.

  2. Further Screening of Entomopathogenic Fungi and Nematodes as Control Agents for Drosophila suzukii

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    Andrew G. S. Cuthbertson

    2016-06-01

    Full Text Available Drosophila suzukii populations remain low in the UK. To date, there have been no reports of widespread damage. Previous research demonstrated that various species of entomopathogenic fungi and nematodes could potentially suppress D. suzukii population development under laboratory trials. However, none of the given species was concluded to be specifically efficient in suppressing D. suzukii. Therefore, there is a need to screen further species to determine their efficacy. The following entomopathogenic agents were evaluated for their potential to act as control agents for D. suzukii: Metarhizium anisopliae; Isaria fumosorosea; a non-commercial coded fungal product (Coded B; Steinernema feltiae, S. carpocapsae, S. kraussei and Heterorhabditis bacteriophora. The fungi were screened for efficacy against the fly on fruit while the nematodes were evaluated for the potential to be applied as soil drenches targeting larvae and pupal life-stages. All three fungi species screened reduced D. suzukii populations developing from infested berries. Isaria fumosorosea significantly (p < 0.001 reduced population development of D. suzukii from infested berries. All nematodes significantly reduced adult emergence from pupal cases compared to the water control. Larvae proved more susceptible to nematode infection. Heterorhabditis bacteriophora proved the best from the four nematodes investigated; readily emerging from punctured larvae and causing 95% mortality. The potential of the entomopathogens to suppress D. suzukii populations is discussed.

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

    Science.gov (United States)

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

    2016-01-22

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

  4. Nematodes, exotic earthworms and nitrogen addition: interactions between global change factors lead to cancellation effects.

    Science.gov (United States)

    De Long, Jonathan R

    2017-07-01

    Photos from the experiment described in Shao et al. (): (a) the endogeic (i.e. earthworms that typically live in the soil, burrowing horizontally to acquire nutrients) earthworm Pontoscolex corethrurus that was added to the plots; (b) P. corethrurus in a quiescence state in response to drought; (c) set-up of the control plots (i.e. no earthworms, ambient nitrogen) used in this experiment. [Colour figure can be viewed at wileyonlinelibrary.com] In Focus: Shao, Y., Zhang, W., Eisenhauer, N., Liu, T., Xiong, Y., Liang, C. & Fu, S. (2017) Nitrogen deposition cancels out exotic earthworm effects on plant-feeding nematode communities. Journal of Animal Ecology, 86, 708-717. In this issue of Journal of Animal Ecology, Shao et al. () explored how N addition and exotic earthworms interacted to impact on the plant-feeding nematode community. They demonstrate that exotic earthworm presence alone increased the abundance of less harmful plant-feeding nematodes and decreased the abundance of the more harmful plant-feeding nematodes. However, in plots receiving both exotic earthworms and N addition, such earthworm effects on the nematode community were negated. These findings pull focus on the need to simultaneously consider multiple global change factors (e.g. exotic species invasions and N deposition) when making predictions about how such factors might affect above- and below-ground interactions and thereby alter ecosystem function. © 2017 The Author. Journal of Animal Ecology © 2017 British Ecological Society.

  5. The significance of ecology in the development of Verticillium chlamydosporium as a biological control agent against root-knot nematodes (Meloidogyne spp.)

    OpenAIRE

    Leij, de, F.A.A.M.

    1992-01-01

    A thorough understanding of the interactions which occur between nematode parasites and nematode pests and the influence of biotic and abiotic factors on these interactions, is essential in the development of biological control agents for nematodes. The aim of this study was to develop a particular isolate of the nematophagous fungus Verticillium chlamydosporium as a biological control agent for root-knot nematodes. The work has gained insight into some of the ke...

  6. Development of a sweet cherry pepper line with resistance to the southern root-knot nematode Meloidogyne incognita

    Science.gov (United States)

    The southern root-knot nematode (Meloidogyne incognita) is a major pathogen of pepper (Capsicum spp.), causing significant yield losses in heavily infected plants. The N-gene confers resistance to M. incognita, and has been successfully used to mitigate nematode damage in specific pepper varieties f...

  7. Behaviour of Heterodera glycines and Meloidogyne incognita infective juveniles exposed to nematode FMRFamide-like peptides in vitro

    Science.gov (United States)

    Plant-parasitic nematodes depend upon a family of neuropeptides, the FMRFamide-like peptides (FLPs), to regulate locomotion and behavior. To exploit FLPs as leads to novel nematode control agents, an understanding of how specific FLPs affect behavior, and what differences exist between species, is i...

  8. Effects of the nematode Gyrinicola batrachiensis on development, gut morphology, and fermentation in bullfrog tadpoles (Rana catesbeiana): a novel mutualism.

    Science.gov (United States)

    Pryor, Gregory S; Bjorndal, Karen A

    2005-08-01

    We describe a novel mutualism between bullfrog tadpoles (Rana catesbeiana) and a tadpole-specific gastrointestinal nematode (Gyrinicola batrachiensis). Groups of tadpoles were inoculated with viable or nonviable nematode eggs, and development, morphology, and gut fermentation activity were compared between nematode-infected and uninfected tadpoles. Nematode infection accelerated tadpole development; the mean time to metamorphosis was 16 d shorter and the range of times to metamorphosis was narrower in nematode-infected tadpoles than in uninfected tadpoles. At metamorphosis, infected and uninfected bullfrogs did not differ in body size or condition. Colon width, wet mass of colon contents, and concentrations of most fermentation byproducts (short-chain fatty acids: SCFAs) in the hindgut were greater in infected tadpoles. Furthermore, in vitro fermentation yields for all SCFAs combined were over twice as high in infected tadpoles than in uninfected tadpoles. One explanation for accelerated development in infected tadpoles is the altered hindgut fermentation associated with the nematodes. Energetic contributions of fermentation were estimated to be 20% and 9% of the total daily energy requirement for infected and uninfected tadpoles, respectively. Infection by G. batrachiensis nematodes potentially confers major ecological and evolutionary advantages to R. catesbeiana tadpoles. The mutualism between these species broadens our understanding of the taxonomic diversity and physiological contributions of fermentative gut symbionts and suggests that nematodes inhabiting the gut regions of other ectothermic herbivores might have beneficial effects in those hosts. Copyright (c) 2005 Wiley-Liss, Inc.

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

    NARCIS (Netherlands)

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

    2004-01-01

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

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

    Science.gov (United States)

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

    2011-04-06

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

  11. Changes in structural and functional diversity of nematode communities during a spring phytoplankton bloom in the southern North Sea

    NARCIS (Netherlands)

    Vanaverbeke, J.; Steyaert, M.; Soetaert, K.E.R.; Rousseau, V.; van Gansbeke, D.; Parent, J-Y.; Vincx, M.

    2004-01-01

    The response of nematode communities to the sedimentation of a spring phytoplankton bloom in a sandy, well-oxygenated sediment at a single station (station 330) in the Southern North Sea was investigated monthly from early March to July 1999. Both structural (nematode density, diversity, vertical

  12. An electron-microscopical analysis of capture and initial stages of penetration of nematodes by Arthrobotrys oligospora

    NARCIS (Netherlands)

    Veenhuis, Marten; Nordbring-Hertz, Birgit; Harder, Wim

    1985-01-01

    A detailed analysis was made of the capture and subsequent penetration of nematodes by the nematophagous fungus Arthrobotrys oligospora using different electron-microscopical techniques. Capture of nematodes by this fungus occurred on complex hyphal structures (traps) and was effectuated by an

  13. [Interactions of straw, nitrogen fertilizer and bacterivorous nematodes on soil labile carbon and nitrogen and greenhouse gas emissions].

    Science.gov (United States)

    Zhang, Teng-Hao; Wang, Nan; Liu, Man-Qiang; Li, Fang-Hui; Zhu, Kang-Li; Li, Hui-Xin; Hu, Feng

    2014-11-01

    A 3 x 2 factorial design of microcosm experiment was conducted to investigate the interactive effects of straw, nitrogen fertilizer and bacterivorous nematodes on soil microbial biomass carbon (C(mic)) and nitrogen (N(mic)), dissolved organic carbon (DOC) and nitrogen (DON), mineral nitrogen (NH(4+)-N and NO(3-)-N), and greenhouse gas (CO2, N2O and CH4) emissions. Results showed that straw amendment remarkably increased the numbers of bacterivorous nematodes and the contents of Cmic and Nmic, but Cmic and Nmic decreased with the increasing dose of nitrogen fertilization. The effects of bacterivorous nematodes strongly depended on either straw or nitrogen fertilization. The interactions of straw, nitrogen fertilization and bacterivorous nematodes on soil DOC, DON and mineral nitrogen were strong. Straw and nitrogen fertilization increased DOC and mineral nitrogen contents, but their influences on DON depended on the bacterivorous nematodes. The DOC and mineral nitrogen were negatively and positively influenced by the bacterivorous nematodes, re- spectively. Straw significantly promoted CO2 and N2O emissions but inhibited CH4 emission, while interactions between nematodes and nitrogen fertilization on emissions of greenhouse gases were obvious. In the presence of straw, nematodes increased cumulative CO2 emissions with low nitrogen fertilization, but decreased CO2 and N2O emissions with high nitrogen fertilization on the 56th day after incubation. In summary, mechanical understanding the soil ecological process would inevitably needs to consider the roles of soil microfauna.

  14. 16D10 siRNAs inhibit root-knot nematode infection in transgenic grape hairy roots

    Science.gov (United States)

    To develop a biotech-based solution for controlling Root-knot nematodes (RKNs) in grapes, we evaluated the efficacy of plant-derived RNA interference (RNAi) silencing of a conserved RKN effector gene, 16D10, for nematode resistance in transgenic grape hairy roots. Two hairpin-based silencing constru...

  15. Soil Nematodes and Their Prokaryotic Prey Along an Elevation Gradient in The Mojave Desert (Death Valley National Park, California, USA

    Directory of Open Access Journals (Sweden)

    Alyxandra Pikus

    2012-10-01

    Full Text Available We characterized soil communities in the Mojave Desert across an elevation gradient. Our goal was to test the hypothesis that as soil quality improved with increasing elevation (due to increased productivity, the diversity of soil prokaryotes and nematodes would also increase. Soil organic matter and soil moisture content increased with elevation as predicted. Soil salinity did not correlate to elevation, but was highest at a mid-gradient, alluvial site. Soil nematode density, community trophic structure, and diversity did not show patterns related to elevation. Similar results were obtained for diversity of bacteria and archaea. Relationships between soil properties, nematode communities, and prokaryotic diversity were site-specific. For example, at the lowest elevation site, nematode communities contained a high proportion of fungal-feeding species and diversity of bacteria was lowest. At a high-salinity site, nematode density was highest, and overall, nematode density showed an unexpected, positive correlation to salinity. At the highest elevation site, nematode density and species richness were attenuated, despite relatively high moisture and organic matter content for the soils. Our results support emerging evidence for the lack of a relationship between productivity and the diversity of soil nematodes and prokaryotes.

  16. Intronic alternative splicing regulators identified by comparative genomics in nematodes.

    Directory of Open Access Journals (Sweden)

    Jennifer L Kabat

    2006-07-01

    Full Text Available Many alternative splicing events are regulated by pentameric and hexameric intronic sequences that serve as binding sites for splicing regulatory factors. We hypothesized that intronic elements that regulate alternative splicing are under selective pressure for evolutionary conservation. Using a Wobble Aware Bulk Aligner genomic alignment of Caenorhabditis elegans and Caenorhabditis briggsae, we identified 147 alternatively spliced cassette exons that exhibit short regions of high nucleotide conservation in the introns flanking the alternative exon. In vivo experiments on the alternatively spliced let-2 gene confirm that these conserved regions can be important for alternative splicing regulation. Conserved intronic element sequences were collected into a dataset and the occurrence of each pentamer and hexamer motif was counted. We compared the frequency of pentamers and hexamers in the conserved intronic elements to a dataset of all C. elegans intron sequences in order to identify short intronic motifs that are more likely to be associated with alternative splicing. High-scoring motifs were examined for upstream or downstream preferences in introns surrounding alternative exons. Many of the high-scoring nematode pentamer and hexamer motifs correspond to known mammalian splicing regulatory sequences, such as (TGCATG, indicating that the mechanism of alternative splicing regulation is well conserved in metazoans. A comparison of the analysis of the conserved intronic elements, and analysis of the entire introns flanking these same exons, reveals that focusing on intronic conservation can increase the sensitivity of detecting putative splicing regulatory motifs. This approach also identified novel sequences whose role in splicing is under investigation and has allowed us to take a step forward in defining a catalog of splicing regulatory elements for an organism. In vivo experiments confirm that one novel high-scoring sequence from our analysis

  17. Genomic response of the nematode Caenorhabditis elegans to spaceflight

    Science.gov (United States)

    Selch, Florian; Higashibata, Akira; Imamizo-Sato, Mari; Higashitani, Atsushi; Ishioka, Noriaki; Szewczyk, Nathaniel J.; Conley, Catharine A.

    On Earth, it is common to employ laboratory animals such as the nematode Caenorhabditis elegans to help understand human health concerns. Similar studies in Earth orbit should help understand and address the concerns associated with spaceflight. The “International Caenorhabditis elegans Experiment FIRST” (ICE FIRST), was carried out onboard the Dutch Taxiflight in April of 2004 by an international collaboration of laboratories in France, Canada, Japan and the United States. With the exception of a slight movement defect upon return to Earth, the result of altered muscle development, no significant abnormalities were detected in spaceflown C. elegans. Work from Japan revealed apoptosis proceeds normally and work from Canada revealed no significant increase in the rate of mutation. These results suggest that C. elegans can be used to study non-lethal responses to spaceflight and can possibly be developed as a biological sensor. To further our understanding of C. elegans response to spaceflight, we examined the gene transcription response to the 10 days in space using a near full genome microarray analysis. The transcriptional response is consistent with the observed normal developmental timing, apoptosis, DNA repair, and altered muscle development. The genes identified as altered in response to spaceflight are enriched for genes known to be regulated, in C. elegans, in response to altered environmental conditions (Insulin and TGF-β regulated). These results demonstrate C. elegans can be used to study the effects of altered gravity and suggest that C. elegans responds to spaceflight by altering the expression of at least some of the same metabolic genes that are altered in response to differing terrestrial environments.

  18. Some camallanid nematodes from marine perciform fishes off New Caledonia.

    Science.gov (United States)

    Moravec, Frantisek; Justine, Jean-Lou; Rigby, Mark C

    2006-09-01

    Two new, one known and three unidentified species of the nematode family Camallanidae are reported and described from the intestines of marine perciform fishes off the southwestern coast of New Caledonia, South Pacific: Camallanus carangis Olsen, 1952 from the forked-tailed threadfin bream Nemipterus furcosus (Nemipteridae), the yellowstriped goatfish Upeneus vittatus and the whitesaddle goatfish Parupeneus ciliatus (both Mullidae) (new host records); Procamallanus (Spirocamallanus) variolae sp. n. from the white-edged lyretail Variola albimarginata (type host) and the blacktip grouper Epinephelus fasciatus (both Serranidae); Procamallanus (Spirocamallanus) longus sp. n. from the twotone tang Zebrasoma scopas (Acanthuridae); Procamallanus (Spirocamallanus) sp. 1 (female tail with 2 terminal spikes on a digit-like projection) from the speckled sand-perch Parapercis hexophtalma (Pinguipedidae); Procamallanus (Spirocamallanus) sp. 2 (female tail with 1 spike on a digit-like projection) from the drab emperor Lethrinus ravus (Lethrinidae) and Procamallanus (Spirocamallanus) sp. 3 (female tail with a smooth digit-like protrusion) from the two-lined monocle bream Scolopsis bilineata (Nemipteridae). Camallanus paracarangis Velasquez, 1980 is synonymized with C. carangis. Several additional species of Camallanus from marine fish of the Indo-Pacific region may be synonymous with C. carangis as it has a poorly sclerotized left spicule and 3 small caudal projections on the tail of young (i.e., non-gravid) females. The fourth-stage larva of C. carangis is described for the first time. P. (S.) variolae differs from most similar species of this region mainly in the position (i.e., at level or posterior to the nerve ring) and shape of deirids. P. (S.) longus differs from the similar P. (S.) chaimha mainly in a different arrangement of postanal papillae, shape of the female tail, much longer right spicule (429 microm) and longer body of gravid females (38-55 mm). All Camallanus and

  19. The significance of ecology in the development of Verticillium chlamydosporium as a biological control agent against root-knot nematodes (Meloidogyne spp.)

    NARCIS (Netherlands)

    Leij, de F.A.A.M.

    1992-01-01

    A thorough understanding of the interactions which occur between nematode parasites and nematode pests and the influence of biotic and abiotic factors on these interactions, is essential in the development of biological control agents for nematodes. The aim of this study was to develop a

  20. Nematode succession and microfauna-microorganism interactions during root residue decomposition

    DEFF Research Database (Denmark)

    Georgieva, Slavka; Christensen, Søren; Andersen, Karen Stevnbak

    2005-01-01

    The quality of plant material affects the vigor of the decomposition process and composition of the decomposer biota. Root residues from hairy vetch (Vicia villosa Roth), rye (Secale cereale L.) and vetch+rye, packed in litterbags were placed in pots of soil at 15 C and the content of the bags...... assemblages (composed of 25 taxa) showed a clear relationship to initial plant resource quality as well as decomposition phase. Early successional microbivorous nematodes vary according to resource quality with demanding bacterivores+predators (Neodiplogasteridae) dominating in vetch and less demanding...... in rye. At week 12 no species dominated the nematode assemblages that were similar between the resources. The differences between nematode assemblages among plant resources at 2 week were similar to the results of a field study sampled after 6 weeks with the same soil and plant resources. This lends...

  1. Development of Anthelmintic Resistance Detection Methods of Gastrointestinal Nematodes on Livestock

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    Dyah Haryuningtyas

    2008-03-01

    Full Text Available The intensive usage of anthelmintic in most of farms led to resistances of livestock gastrointestinal nematodes against anthelmintic. Many reports of resistance that increased every year happen following the continuing helminth control programmes. The succesful implementation of helminth control programmes that designed to minimize the development of resistance in nematode populations depends on the availability of effective and sensitive method for its detection and monitoring. A variety of in vivo and in vitro tests have been developed for detecting nematode population resistance to the main anthelmintic groups. This paper will discuss the development of detection method of anthelmintic resistance based on conventional and molecular approach according to their strengths and weakness.

  2. Free-living marine nematodes from San Julián Bay (Santa Cruz, Argentina)

    Science.gov (United States)

    Pastor de Ward, Catalina; Lo Russo, Virginia; Villares, Gabriela; Milano, Viviana; Miyashiro, Lidia; Mazzanti, Renato

    2015-01-01

    Abstract The free-living marine nematodes of San Julián Bay dataset is based on sediment samples collected in January 2009 during the project PICT AGENCIA-FONCYT 2/33345-2005. A total of 36 samples have been taken at three locations in the San Julián Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for the nematode benthic biodiversity assessment as this area remains one of the least known regions in Patagonia. In total 10,030 specimens of free-living marine nematodes belonging to 2 classes, 9 orders, 35 families, 78 genera and 125 species were collected. The San Julián city site presented a very high species richness. PMID:25878534

  3. Free-living marine nematodes from San Julián Bay (Santa Cruz, Argentina

    Directory of Open Access Journals (Sweden)

    Catalina Pastor de Ward

    2015-03-01

    Full Text Available The free-living marine nematodes of San Julián Bay dataset is based on sediment samples collected in January 2009 during the project PICT AGENCIA-FONCYT 2/33345-2005. A total of 36 samples have been taken at three locations in the San Julián Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for the nematode benthic biodiversity assessment as this area remains one of the least known regions in Patagonia. In total 10,030 specimens of free-living marine nematodes belonging to 2 classes, 9 orders, 35 families, 78 genera and 125 species were collected. The San Julián city site presented a very high species richness.

  4. Findings of Entomopathogenic Nematodes (Rhabditida, Steinernematidae in Nature Reserves in Ukraine

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    Yakovlev Ye. B.

    2014-07-01

    Full Text Available Findings of Entomopathogenic Nematodes (Rhabditida, Steinernematidae in Nature Reserves in-Ukraine. Yakovlev, Ye. B., Kharchenko, V. A., Mráček, Z. — Five strains of Steinernema Travassos, 1927 were isolated by live baiting method with last instar larvae of Tenebrio molitor Linnaeus, 1758 from the reserves of some central and southern oblasts of Ukraine and the Crimean AR. Entomopathogenic nematodes were recovered from 5 of 196 (2.6 % soil samples collected in 2010. Isolated nematodes were identified using a combination of molecular (ITS1-5.8S-ITS2 rDNA gene sequencing and morphological techniques. Four of the isolated strains were recognized as S. feltiae (Filipjev, 1934, one as S. arenarium (Artyukhovsky, 1967.

  5. Nematodes associated with five fruit trees in the state of Amapá, Brazil

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    Rodrigo Souza Santos

    2016-01-01

    Full Text Available ABSTRACT: The aim of this study was to conduct a survey on nematodes associated with five cultivated fruit trees growing in the Agroforestry System (AFS of the municipality of Oiapoque, Amapá, Brazil. Rhizosphere samples were collected from three points at the base of murici ( Byrsonima sp., soursop ( Annona muricata , cupuaçu ( Theobroma grandiflorum , passion fruit ( Passiflora sp. and peach palm ( Bactris gasipaes trees. Four species of phytonematodes were identified, namely Pratylenchus brachyurus, Helicotylenchus dihystera, Mesocriconema xenoplax and Rotylenchulus reniformis . The most prevalent and abundant species was R. reniformis , which was found in the rhizospheres of passion fruit, cupuaçu, soursop, and peach palm. The first record in Brazil of the nematode P. brachyurus , found in the roots of murici is reported here, and all of the nematode species identified here are the first records for fruit trees in the state of Amapá.

  6. Three Nematode Species Recovered from Terrestrial Snakes in Republic of Korea.

    Science.gov (United States)

    Choe, Seongjun; Lim, Junsik; Kim, Hyun; Kim, Youngjun; Kim, Heejong; Lee, Dongmin; Park, Hansol; Jeon, Hyeong-Kyu; Eom, Keeseon S

    2016-04-01

    The majority of parasitological studies of terrestrial snakes in Korea have focused on zoonotic parasites. However, in the present study, we describe 3 unrecorded nematode species recovered from 5 species of snakes (n=6) in Korea. The examined snakes, all confiscated from illegal hunters, were donated by the Chungnam Wild Animal Rescue Center and Korean Broadcasting System in July 2014 and February 2015. Light and scanning electron microscopies on the shapes of spicules that are either bent or straight (kalicephalids) and the presence of the intestinal cecum (ophidascarids) figured out 3 nematodes; Kalicephalus brachycephalus Maplestone, 1931, Kalicephalus sinensis Hsü, 1934, and Ophidascaris excavata Hsü and Hoeppli, 1934. These 3 species of nematode faunas are recorded for the first time in Korea.

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

    Directory of Open Access Journals (Sweden)

    A. F. Al-Taee

    2011-01-01

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

  8. Investigation of Nematode Diversity using Scanning Electron Microscopy and Fluorescent Microscopy

    Science.gov (United States)

    Seacor, Taylor; Howell, Carina

    2013-03-01

    Nematode worms account for the vast majority of the animals in the biosphere. They are colossally important to global public health as parasites, and to agriculture both as pests and as beneficial inhabitants of healthy soil. Amphid neurons are the anterior chemosensory neurons in nematodes, mediating critical behaviors including chemotaxis and mating. We are examining the cellular morphology and external anatomy of amphid neurons, using fluorescence microscopy and scanning electron microscopy, respectively, of a wide range of soil nematodes isolated in the wild. We use both classical systematics (e.g. diagnostic keys) and molecular markers (e.g. ribosomal RNA) to classify these wild isolates. Our ultimate aim is to build a detailed anatomical database in order to dissect genetic pathways of neuronal development and function across phylogeny and ecology. Research supported by NSF grants 092304, 0806660, 1058829 and Lock Haven University FPDC grants

  9. Micro-electro-fluidic grids for nematodes: a lens-less, image-sensor-less approach for on-chip tracking of nematode locomotion.

    Science.gov (United States)

    Liu, Peng; Martin, Richard J; Dong, Liang

    2013-02-21

    This paper reports on the development of a lens-less and image-sensor-less micro-electro-fluidic (MEF) approach for real-time monitoring of the locomotion of microscopic nematodes. The technology showed promise for overcoming the constraint of the limited field of view of conventional optical microscopy, with relatively low cost, good spatial resolution, and high portability. The core of the device was microelectrode grids formed by orthogonally arranging two identical arrays of microelectrode lines. The two microelectrode arrays were spaced by a microfluidic chamber containing a liquid medium of interest. As a nematode (e.g., Caenorhabditis elegans) moved inside the chamber, the invasion of part of its body into some intersection regions between the microelectrodes caused changes in the electrical resistance of these intersection regions. The worm's presence at, or absence from, a detection unit was determined by a comparison between the measured resistance variation of this unit and a pre-defined threshold resistance variation. An electronic readout circuit was designed to address all the detection units and read out their individual electrical resistances. By this means, it was possible to obtain the electrical resistance profile of the whole MEF grid, and thus, the physical pattern of the swimming nematode. We studied the influence of a worm's body on the resistance of an addressed unit. We also investigated how the full-frame scanning and readout rates of the electronic circuit and the dimensions of a detection unit posed an impact on the spatial resolution of the reconstructed images of the nematode. Other important issues, such as the manufacturing-induced initial non-uniformity of the grids and the electrotaxic behaviour of nematodes, were also studied. A drug resistance screening experiment was conducted by using the grids with a good resolution of 30 × 30 μm(2). The phenotypic differences in the locomotion behaviours (e.g., moving speed and oscillation

  10. Stomach nematodes (Mastophorus Muris) in rats (Rattus rattus) are associated with coconut (Cocos nucifera) Habitat at palmyra atoll

    Science.gov (United States)

    Lafferty, K.D.; Hathaway, S.A.; Wegmann, A.S.; Shipley, F.S.; Backlin, A.R.; Helm, J.; Fisher, R.N.

    2010-01-01

    Black rats (Rattus rattus) and their stomach nematodes (Mastophorus muris) were historically introduced to islets at Palmyra Atoll in the central Pacific Line Islands. To investigate patterns of parasitism, we trapped rats and quantified nematodes on 13 islets of various sizes and habitat types. Most rats were parasitized (59) with an average of 12 worms per infected rat. Islet size did not greatly influence parasite population biology. Nematodes also did not appear to affect rat condition (weight to skull length). The only strong and consistent factor associated with the mean abundance of nematodes in rats was habitat (dominant cover and locally dominant plant species). Thus, nematodes were much more abundant in rats from sites dominated by coconut trees (Cocos nucifera). Coconut trees may also be an introduced species at Palmyra Atoll. ?? American Society of Parasitologists 2010.

  11. Stomach nematodes (Mastophorus muris) in rats (Rattus rattus) are associated with coconut (Cocos nucifera) habitat at Palmyra Atoll.

    Science.gov (United States)

    Lafferty, Kevin D; Hathaway, Stacie A; Wegmann, Alex S; Shipley, Frank S; Backlin, Adam R; Helm, Joel; Fisher, Robert N

    2010-02-01

    Black rats ( Rattus rattus ) and their stomach nematodes (Mastophorus muris) were historically introduced to islets at Palmyra Atoll in the central Pacific Line Islands. To investigate patterns of parasitism, we trapped rats and quantified nematodes on 13 islets of various sizes and habitat types. Most rats were parasitized (59%) with an average of 12 worms per infected rat. Islet size did not greatly influence parasite population biology. Nematodes also did not appear to affect rat condition (weight to skull length). The only strong and consistent factor associated with the mean abundance of nematodes in rats was habitat (dominant cover and locally dominant plant species). Thus, nematodes were much more abundant in rats from sites dominated by coconut trees (Cocos nucifera). Coconut trees may also be an introduced species at Palmyra Atoll.

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

    Science.gov (United States)

    Leung, Tommy L F; Koprivnikar, Janet

    2016-11-01

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

  13. A new look into the small-scale dispersal of free-living marine nematodes

    Directory of Open Access Journals (Sweden)

    Micheli C Thomas

    2011-08-01

    Full Text Available We tested experimentally the hypothesis that prevailing locomotion/feeding strategies and body morphology may lead to more active dispersal of free-living marine nematodes, besides passive transport. Neutral Red was applied to the sediment inside cores and the red plume formed during the flood tide was divided into near, middle, and distant zones. At 0.5 m and 1 m from the stained cores, sampling nets were suspended 5 and 10 cm above the sediment-water interface. Dispersion behaviors were defined as a function of a the numbers of stained recaptured nematodes in comparison to their mean densities in the sediment, b movement in the sediment or swimming in the water column, and c body morphology. Tidal currents with average velocities of 9 cm/s resuspended the numerically dominant nematode taxa Sabatieria sp., Terschellingia longicaudata de Man, 1907, Metachromadora sp. and Viscosia sp. The recapture of stained nematodes as far as 2 m from the original stained cores showed that, despite their small body size, they can disperse through relatively large distances, either passively or actively, via the water column during a single tidal event. Recapture patterns in the sediment and in the water column indicate that nematode dispersal is directly influenced by their body morphology and swimming ability, and indirectly by their feeding strategies, which ultimately define their position in the sediment column. Besides stressing the role played by passive transport in the water column, our experiment additionally showed that mobility and feeding strategies also need to be considered as determinant of short-scale nematode dispersal.

  14. A Cross-Reactive Monoclonal Antibody to Nematode Haemoglobin Enhances Protective Immune Responses to Nippostrongylus brasiliensis

    Science.gov (United States)

    Nieuwenhuizen, Natalie E.; Meter, Jeanne M.; Horsnell, William G.; Hoving, J. Claire; Fick, Lizette; Sharp, Michael F.; Darby, Matthew G.; Parihar, Suraj P.; Brombacher, Frank; Lopata, Andreas L.

    2013-01-01

    Background Nematode secreted haemoglobins have unusually high affinity for oxygen and possess nitric oxide deoxygenase, and catalase activity thought to be important in protection against host immune responses to infection. In this study, we generated a monoclonal antibody (48Eg) against haemoglobin of the nematode Anisakis pegreffii, and aimed to characterize cross-reactivity of 4E8g against haemoglobins of different nematodes and its potential to mediate protective immunity against a murine hookworm infection. Methodology/Principal Findings Immunoprecipitation was used to isolate the 4E8g-binding antigen in Anisakis and Ascaris extracts, which were identified as haemoglobins by peptide mass fingerprinting and MS/MS. Immunological cross-reactivity was also demonstrated with haemoglobin of the rodent hookworm N. brasiliensis. Immunogenicity of nematode haemoglobin in mice and humans was tested by immunoblotting. Anisakis haemoglobin was recognized by IgG and IgE antibodies of Anisakis-infected mice, while Ascaris haemoglobin was recognized by IgG but not IgE antibodies in mouse and human sera. Sequencing of Anisakis haemoglobin revealed high similarity to haemoglobin of a related marine nematode, Psuedoterranova decipiens, which lacks the four –HKEE repeats of Ascaris haemoglobin important in octamer assembly. The localization of haemoglobin in the different parasites was examined by immunohistochemistry and associated with the excretory-secretary ducts in Anisakis, Ascaris and N. brasiliensis. Anisakis haemoglobin was strongly expressed in the L3 stage, unlike Ascaris haemoglobin, which is reportedly mainly expressed in adult worms. Passive immunization of mice with 4E8g prior to infection with N. brasiliensis enhanced protective Th2 immunity and led to a significant decrease in worm burdens. Conclusion The monoclonal antibody 4E8g targets haemoglobin in broadly equivalent anatomical locations in parasitic nematodes and enhances host immunity to a hookworm

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

    Directory of Open Access Journals (Sweden)

    Mesfin eWondafrash

    2013-04-01

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

  16. Influence of chemosynthetic ecosystems on nematode community structure and biomass in the deep eastern Mediterranean Sea

    Science.gov (United States)

    Lampadariou, N.; Kalogeropoulou, V.; Sevastou, K.; Keklikoglou, K.; Sarrazin, J.

    2013-08-01

    Mud volcanoes are a~special type of cold seeps where life is based on chemoautotrophic processes. They are considered to be extreme environments and are characterized by unique megafaunal and macrofaunal communities. However, very few studies on mud volcanoes taking into account the smaller meiobenthic communities have been carried out. Two mud volcanoes were explored during the MEDECO (MEditerranean Deep-sea ECOsystems) cruise (2007) with the remotely operated vehicle (ROV) Victor-6000: Amsterdam, located south of Turkey between 1700 and 2000 m depth (Anaximander mud field); and Napoli, south of Crete, located along the Mediterranean Ridge at about 2000 m depth (Olimpi mud field). The major aim of this study was to describe distributional patterns of meiofaunal communities and nematode assemblages from different seep microhabitats. Meiofaunal taxa and nematode assemblages at both mud volcanoes differed significantly from other Mediterranean sites in terms of standing stocks, dominance and species diversity. Density and biomass values were significantly higher at the seep sites, particularly at Amsterdam. Patterns of nematode diversity, the dominant meiofaunal taxon, varied, displaying both very high or very low species richness and dominance, depending on the microhabitat studied. The periphery of the Lamellibrachia and bivalve shell microhabitats of Napoli exhibited the highest species richness, while the reduced sediments of Amsterdam yielded a species-poor nematode community dominated by two successful species, one belonging to the genus Aponema and the other to the genus Sabatieria. Analysis of β-diversity showed that microhabitat heterogeneity of mud volcanoes contributed substantially to the total nematode species richness in the eastern Mediterranean Sea. These observations indicate a strong influence of mud volcanoes and cold-seep ecosystems on the meiofaunal communities and nematode assemblages.

  17. Influence of chemosynthetic ecosystems on nematode community structure and biomass in the deep eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    N. Lampadariou

    2013-08-01

    Full Text Available Mud volcanoes are a~special type of cold seeps where life is based on chemoautotrophic processes. They are considered to be extreme environments and are characterized by unique megafaunal and macrofaunal communities. However, very few studies on mud volcanoes taking into account the smaller meiobenthic communities have been carried out. Two mud volcanoes were explored during the MEDECO (MEditerranean Deep-sea ECOsystems cruise (2007 with the remotely operated vehicle (ROV Victor-6000: Amsterdam, located south of Turkey between 1700 and 2000 m depth (Anaximander mud field; and Napoli, south of Crete, located along the Mediterranean Ridge at about 2000 m depth (Olimpi mud field. The major aim of this study was to describe distributional patterns of meiofaunal communities and nematode assemblages from different seep microhabitats. Meiofaunal taxa and nematode assemblages at both mud volcanoes differed significantly from other Mediterranean sites in terms of standing stocks, dominance and species diversity. Density and biomass values were significantly higher at the seep sites, particularly at Amsterdam. Patterns of nematode diversity, the dominant meiofaunal taxon, varied, displaying both very high or very low species richness and dominance, depending on the microhabitat studied. The periphery of the Lamellibrachia and bivalve shell microhabitats of Napoli exhibited the highest species richness, while the reduced sediments of Amsterdam yielded a species-poor nematode community dominated by two successful species, one belonging to the genus Aponema and the other to the genus Sabatieria. Analysis of β-diversity showed that microhabitat heterogeneity of mud volcanoes contributed substantially to the total nematode species richness in the eastern Mediterranean Sea. These observations indicate a strong influence of mud volcanoes and cold-seep ecosystems on the meiofaunal communities and nematode assemblages.

  18. Genomic and proteomic analyses of the fungus Arthrobotrys oligospora provide insights into nematode-trap formation.

    Directory of Open Access Journals (Sweden)

    Jinkui Yang

    2011-09-01

    Full Text Available Nematode-trapping fungi are "carnivorous" and attack their hosts using specialized trapping devices. The morphological development of these traps is the key indicator of their switch from saprophytic to predacious lifestyles. Here, the genome of the nematode-trapping fungus Arthrobotrys oligospora Fres. (ATCC24927 was reported. The genome contains 40.07 Mb assembled sequence with 11,479 predicted genes. Comparative analysis showed that A. oligospora shared many more genes with pathogenic fungi than with non-pathogenic fungi. Specifically, compared to several sequenced ascomycete fungi, the A. oligospora genome has a larger number of pathogenicity-related genes in the subtilisin, cellulase, cellobiohydrolase, and pectinesterase gene families. Searching against the pathogen-host interaction gene database identified 398 homologous genes involved in pathogenicity in other fungi. The analysis of repetitive sequences provided evidence for repeat-induced point mutations in A. oligospora. Proteomic and quantitative PCR (qPCR analyses revealed that 90 genes were significantly up-regulated at the early stage of trap-formation by nematode extracts and most of these genes were involved in translation, amino acid metabolism, carbohydrate metabolism, cell wall and membrane biogenesis. Based on the combined genomic, proteomic and qPCR data, a model for the formation of nematode trapping device in this fungus was proposed. In this model, multiple fungal signal transduction pathways are activated by its nematode prey to further regulate downstream genes associated with diverse cellular processes such as energy metabolism, biosynthesis of the cell wall and adhesive proteins, cell division, glycerol accumulation and peroxisome biogenesis. This study will facilitate the identification of pathogenicity-related genes and provide a broad foundation for understanding the molecular and evolutionary mechanisms underlying fungi-nematodes interactions.

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

    Science.gov (United States)

    Hering-Hagenbeck, S F; Boomker, J

    2000-03-01

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

  20. The Role of Programmed Cell Death Regulator LSD1 in Nematode-Induced Syncytium Formation

    Science.gov (United States)

    Matuszkiewicz, Mateusz; Sobczak, Miroslaw; Cabrera, Javier; Escobar, Carolina; Karpiński, Stanislaw; Filipecki, Marcin

    2018-01-01

    Cyst-forming plant-parasitic nematodes are common pests of many crops. They inject secretions into host cells to induce the developmental and metabolic reprogramming that leads to the formation of a syncytium, which is the sole food source for growing nematodes. As in other host-parasite models, avirulence leads to rapid and local programmed cell death (PCD) known as the hypersensitive response (HR), whereas in the case of virulence, PCD is still observed but is limited to only some cells. Several regulators of PCD were analyzed to understand the role of PCD in compatible plant–nematode interactions. Thus, Arabidopsis plants carrying recessive mutations in LESION SIMULATING DISEASE1 (LSD1) family genes were subjected to nematode infection assays with juveniles of Heterodera schachtii. LSD1 is a negative and conditional regulator of PCD, and fewer and smaller syncytia were induced in the roots of lsd1 mutants than in wild-type Col-0 plants. Mutation in LSD ONE LIKE2 (LOL2) revealed a pattern of susceptibility to H. schachtii antagonistic to lsd1. Syncytia induced on lsd1 roots compared to Col0 showed significantly retarded growth, modified cell wall structure, increased vesiculation, and some myelin-like bodies present at 7 and 12 days post-infection. To place these data in a wider context, RNA-sequencing analysis of infected and uninfected roots was conducted. During nematode infection, the number of transcripts with changed expression in lsd1 was approximately three times smaller than in wild-type plants (1440 vs. 4206 differentially expressed genes, respectively). LSD1-dependent PCD in roots is thus a highly regulated process in compatible plant–nematode interactions. Two genes identified in this analysis, coding for AUTOPHAGY-RELATED PROTEIN 8F and 8H were down-regulated in syncytia in the presence of LSD1 and showed an increased susceptibility to nematode infection contrasting with lsd1 phenotype. Our data indicate that molecular regulators belonging to the

  1. Free-living marine nematodes from San Julián Bay (Santa Cruz, Argentina)

    OpenAIRE

    Pastor, Catalina Teresa; Lo Russo, Virginia; Villares, Maria Gabriela; Milano, Viviana; Miyashiro, Lidia; Mazzanti, Renato

    2017-01-01

    The free-living marine nematodes of San Julián Bay dataset is based on sediment samples collected in January 2009 during the project PICT AGENCIA-FONCYT 2/33345-2005. A total of 36 samples have been taken at three locations in the San Julián Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for the nematode benthic biodiversity assessment as this area remains one of the least known regions in Patagonia. In total ...

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

    DEFF Research Database (Denmark)

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

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

  3. The nematode Goezia sp. (Anisakidae) from Bagrus bayad (Osteichthyes) from Egypt.

    Science.gov (United States)

    El Alfi, Nadia M

    2005-04-01

    The present study describes nematode infection in the freshwater fish Bagrus bayad (Osteichthyes) collected from the Red Sea at Suez Canal Zone. Of 32 examined fish, 21 (65%) were infected with Goezia sp. (Nematoda: Family: Anisakidae) with mean ntensity of 4.1 parasites. The nematode present here differs from Goezia braziliensis, G. breviaeca and G. intermedia, as well as from other species described. The main difference was in the greater number of pre-anal papillae in males compared to G. braziliensis. The present parasite also differs from G. braziliensis in spicule length and distance of vulva from the anterior extremity.

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

    Directory of Open Access Journals (Sweden)

    A.C.M. Lizanne

    2014-01-01

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

  5. Transcriptome Analysis of Cotton (Gossypium hirsutum L.) Genotypes That Are Susceptible, Resistant, and Hypersensitive to Reniform Nematode (Rotylenchulus reniformis).

    Science.gov (United States)

    Li, Ruijuan; Rashotte, Aaron M; Singh, Narendra K; Lawrence, Kathy S; Weaver, David B; Locy, Robert D

    2015-01-01

    Reniform nematode is a semi-endoparasitic nematode species causing significant yield loss in numerous crops, including cotton (Gossypium hirsutum L.). An RNA-sequencing analysis was conducted to measure transcript abundance in reniform nematode susceptible (DP90 & SG747), resistant (BARBREN-713), and hypersensitive (LONREN-1) genotypes of cotton (Gossypium hirsutum L.) with and without reniform nematode infestation. Over 90 million trimmed high quality reads were assembled into 84,711 and 80, 353 transcripts using the G. arboreum and the G. raimondii genomes as references. Many transcripts were significantly differentially expressed between the three different genotypes both prior to and during nematode pathogenesis, including transcripts corresponding to the gene ontology categories of cell wall, hormone metabolism and signaling, redox reactions, secondary metabolism, transcriptional regulation, stress responses, and signaling. Further analysis revealed that a number of these differentially expressed transcripts mapped to the G. raimondii and/or the G. arboreum genomes within 1 megabase of quantitative trait loci that had previously been linked to reniform nematode resistance. Several resistance genes encoding proteins known to be strongly linked to pathogen perception and resistance, including LRR-like and NBS-LRR domain-containing proteins, were among the differentially expressed transcripts mapping near these quantitative trait loci. Further investigation is required to confirm a role for these transcripts in reniform nematode susceptibility, hypersensitivity, and/or resistance. This study presents the first systemic investigation of reniform nematode resistance-associated genes using different genotypes of cotton. The candidate reniform nematode resistance-associated genes identified in this study can serve as the basis for further functional analysis and aid in further development of reniform a nematode resistant cotton germplasm.

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

    Directory of Open Access Journals (Sweden)

    Huan Peng

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

  7. COMPARATIVE STUDY OF FILARIAL DETECTION BY MICROSCOPIC EXAMINATION AND SEROLOGICAL ASSAY UTILIZING BMR1 AND BMXSP RECOMBINANT ANTIGENS FOR EVALUATION OF FILARIASIS ELIMINATION PROGRAM AT KAMPUNG SAWAH AND PAMULANG, SOUTH TANGERANG DISTRICT, BANTEN, INDONESIA

    Directory of Open Access Journals (Sweden)

    Silvia F. Nasution

    2015-09-01

    Full Text Available South Tangerang district is one of the endemic areas for filariasis; and based on an evaluation study in 2008-2009 which covered several subdistricts, the prevalence of microfilaria was between 1–2.4%. Nevertheless, the evaluation by serological assay has never been reported. A cross-sectional study was conducted to detect the microfilaremia and anti-filarial IgG4 antibody status in Kp Sawah and Pamulang subdistricts. Cluster sampling was performed in Kp Sawah by collecting finger-prick blood (FPB and venous blood samples from inhabitants who lived with and nearby the four elephantiasis subjects in the area. The FPB were only collected in Pamulang area by consecutive sampling method. The detection method included microscopic evaluation of FPB and serological detection using recombinant antigens BmR1 and BmSXP by ELISA and lateral flow rapid tests. Symptomatic patients who had 2nd and 3rd degree of elephantiasis were clinically determined in 10% (4/40 subjects. Among those with elephantiasis, 2 were positive serologically but their microscopic results were all negative (40/40. Meanwhile, the microscopic result for 107 subjects from Pamulang were all negative. The results of the rapid tests showed that 15% (6/40 of the positive cases were detected by Brugia Rapid and 27.5% (11/40 by PanLF. Meanwhile, the ELISA showed that 20% (8/40 of the cases were positive with BmSXP, whereas only 2.5% or 1/40 sample was found to be positive with BmR1. Even though the sensitivity of the Rapid test was lower when compared to microscopic examination for these samples, the assay showed good specificity ranging from 72.5 to 97.5%. The optical density (OD values of ELISA has ranged between 0.3–3.045.

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

    Directory of Open Access Journals (Sweden)

    WANG Yu-kun

    2017-05-01

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

  9. Chitosan-based nanoparticles of avermectin to control pine wood nematodes.

    Science.gov (United States)

    Liang, Wenlong; Yu, Aixin; Wang, Guodong; Zheng, Feng; Jia, Jinliang; Xu, Hanhong

    2018-06-01

    Pine wood nematode disease is a most devastating disease of pine trees. Avermectin (AVM) is a widely used bio-nematocide which can effectively to kill the pine wood nematode (PWN). However, its poor solubility in water and rapid photolysis are responsible for its poor bioavailability, which causes environmental pollution because of excessive applied rates. Here, a simple electrostatic interaction method was used to encapsulate AVM within nanoparticles composed of poly-γ-glutamic acid (γ-PGA) and chitosan (CS). The loading capacity of the resulting AVM-CS/γ-PGA nanoparticles was as much as 30.5%. The encapsulation of AVM within these nanoparticles reduced its losses by more than 20.0% through photolysis. An in vitro test showed that the rate of release of AVM from the nanoparticles was dependent on the ambient pH, with rapid release occurring in an alkaline environment. The mortality rate of nematodes which were treated with 1ppm of AVM content of AVM-CS/γ-PGA was 98.6% after 24h, while one of free AVM was only 69.9%. In addition, FITC-labeled CS/γ-PGA nanoparticles (FITC-CS/γ-PGA) showed that the nanoparticles could enrich in intestines and head of nematodes. All of these results showed that those nanoparticles of AVM are a potential multifunctional formulation to control the pest and reduce environment pollution. Copyright © 2018 Elsevier B.V. All rights reserved.

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

    Czech Academy of Sciences Publication Activity Database

    Moravec, František

    2007-01-01

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

  11. Repertoire and evolution of miRNA genes in four divergent nematode species.

    NARCIS (Netherlands)

    de Wit, E.; Linsen, S.E.V.; Cuppen, E.; Berezikov, E.

    2009-01-01

    miRNAs are approximately 22-nt RNA molecules that play important roles in post-transcriptional regulation. We have performed small RNA sequencing in the nematodes Caenorhabditis elegans, C. briggsae, C. remanei, and Pristionchus pacificus, which have diverged up to 400 million years ago, to

  12. Steinernema ichnusae sp. n. (Nematoda: Steinernematide) a new entomopathogenic nematode from Sardinia Islands (Italy)

    Czech Academy of Sciences Publication Activity Database

    Tarasco, E.; Mráček, Zdeněk; Nguyen, K. B.; Triggiani, O.

    2008-01-01

    Roč. 99, č. 2 (2008), s. 173-185 ISSN 0022-2011 Institutional research plan: CEZ:AV0Z50070508 Keywords : 28S rDNA sequence * entomopathogenic nematode * new species Subject RIV: EG - Zoology Impact factor: 2.005, year: 2008

  13. First report of the root-knot nematode Meloidogyne marylandi on Turfgrasses in Israel

    NARCIS (Netherlands)

    Oka, Y.; Karssen, G.; Mor, M.

    2004-01-01

    In a turfgrass nursery in Arava, Israel, a population of root-knot nematodes was isolated from poorly growing Zoysiagrass (Zoysia japonica Steud.) with symptoms of foliar chlorosis and roots with very small, smooth galls and protruding egg masses. The isolated population (genus Meloidogyne) included

  14. Transgressive segregation of root-knot nematode resistance in cotton determined by QTL analysis

    Science.gov (United States)

    Transgressive resistance to root-knot nematode, Meloidogyne incognita, was found in intraspecific (Gossypium hirsutum; resistant Acala NemX x susceptible Acala SJ-2) and interspecific (G. barbadense susceptible Pima-S7 x Acala NemX) cotton recombinant inbred line (RIL) populations. Similar contribut...

  15. Cultivation of the Pine Wilt Nematode, Bursaphelenchus xylophilus, in Axenic Culture Media

    OpenAIRE

    Bolla, R. I.; Jordan, W.

    1982-01-01

    The pine wilt nematode, Bursaphelenchus xylophilus, has been cultured axenically in vitro on soy peptone/yeast extract or modified Caenorhabditis medium supplemented with cholesterol and hemoglobin. Although growth, development and reproduction were best in soy peptone/yeast extract medium, satisfactory population size increases were observed in the chemically defined Caenorhaditis medium.

  16. Cytological changes of Easter lily (Lilium longiflorum) upon root lesion nematode (Pratylenchus penetrans) infection

    Science.gov (United States)

    Lilium longiflorum cv. Nellie White, commonly known as Easter lily, is an important floral crop with an annual wholesale value of over $26 million in the U.S. The root lesion nematode (RLN), Pratylenchus penetrans, is a major pest of lily due to the significant root damage it causes. In this study w...

  17. Expression of a cystatin transgene can confer resistance to root lesion nematodes in Lilium longiflorum

    Science.gov (United States)

    Lilium longiflorum cv. “Nellie White” is an economically important cut flower, being one of the most valuable species with an annual wholesale value above $20,000,000 for pot plants sold in the US. The root lesion nematode (Pratylenchus penetrans) is one of the main pests for lily producers due to...

  18. Predatory Capacity in vitro of Native Nematophagous Fungi from Cundinamarca on Gastrointestinal Nematodes of Cattle

    Directory of Open Access Journals (Sweden)

    Dildo Márquez Lara

    2015-12-01

    Full Text Available Dependence and indiscriminate use of chemical anthelmintics as the sole method for controlling gastrointestinal nematodes (GIN of cattle causes problems in the environment, public health, and the productivity of cattle. It is important to develop non-chemical control strategies. Nematophagous fungi can be a viable and promising alternative for the control of these endoparasites. This study aimed to isolate, identify and evaluate in vitro the potential of nematophagous fungi from Cundinamarca on L3 larvae of gastrointestinal nematodes of cattle. 60 soil samples from cattle ranches were sown in Petri boxes containing agar-water for trapping fungi, and three strains of the fungus Arthrobotrys oligospora (L1, XVIII, and XXI and one of Arthrobotrys musiformis (XXIV were identified by morphometric keys. 1 x 106 conidia or chlamydospores of each fungi were used, which faced 100 nematode larvae. Isolate XXIV (A. musiformis showed greater predatory capacity (96.8% than isolates (A. oligospora XVIII, L1, and XXI (69.68, 71.1, and 87.62%, respectively. There were no statistically significant differences (p > 0.05 among the strains with more predatory capacity. This is the first record of in vitro identification and evaluation of the predatory capacity of A. oligospora and A. musiformis, native fungi from Cundinamarca. The results suggest that these fungi could be used as biocontrol agents of nematodes in cattle.

  19. Nematode Community Response to Green Infrastructure Design in a Semiarid City.

    Science.gov (United States)

    Pavao-Zuckerman, Mitchell A; Sookhdeo, Christine

    2017-05-01

    Urbanization affects ecosystem function and environmental quality through shifts in ecosystem fluxes that are brought on by features of the built environment. Green infrastructure (GI) has been suggested as a best management practice (BMP) to address urban hydrologic and ecological impacts of the built environment, but GI practice has only been studied from a limited set of climatic conditions and disciplinary approaches. Here, we evaluate GI features in a semiarid city from the perspective of soil ecology through the application of soil nematode community analysis. This study was conducted to investigate soil ecological interactions in small-scale GI as a means of assessing curb-cut rain garden basin design in a semiarid city. We looked at the choice of mulching approaches (organic vs. rock) and how this design choice affects the soil ecology of rain basins in Tucson, AZ. We sampled soils during the monsoon rain season and assessed the soil nematode community as a bioindicator of soil quality and biogeochemical processes. We found that the use of organic mulch in GI basins promotes enhanced soil organic matter contents and larger nematode populations. Nematode community indices point to enhanced food web structure in streetscape rain garden basins that are mulched with organic material. Results from this study suggest that soil management practices for GI can help promote ecological interactions and ecosystem services in urban ecosystems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

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

    Directory of Open Access Journals (Sweden)

    Claire Villemant

    2015-05-01

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

  1. screening of in-vitro derived mutants of banana against nematodes ...

    African Journals Online (AJOL)

    Venkat

    AAA) and Rasthali (Silk- AAB) by using certain bio-chemical parameters including some enzyme activities. The mutants ... Key words: Banana, nematode, resistance, biochemical parameters, enzymes, screening. INTRODUCTION ..... superoxide dismutase, catalase and perioxidase with reference to resistance in tomato to ...

  2. Some nematodes of fishes from central China, with the redescription of Procamallanus (Spirocamallanus) fulvidraconis (Camallanidae)

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Nie, P.; Wang, G.

    2003-01-01

    Roč. 50, č. 3 (2003), s. 220-230 ISSN 0015-5683 R&D Projects: GA MŠk ME 424 Grant - others:National Natural Science Foundation of China(CN) 30025035 Institutional research plan: CEZ:AV0Z6022909 Keywords : parasitic nematodes * freshwater fishes * China Subject RIV: EA - Cell Biology Impact factor: 0.469, year: 2003

  3. Soybean Pl 494182: A new source of more durable resistance to nematode populations

    Science.gov (United States)

    Soybean cyst nematode (SCN; Heterodera glycines Ichinohe) is the most pervasive pest of soybean [Glycine max (L.) Merr.] in the United States and worldwide. In 2012, SCN reduced yields in the U.S. by an estimated $1 billion. These losses have been contained at a stable level with the use of resistan...

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

    NARCIS (Netherlands)

    Biere, A.; Goverse, A.

    2016-01-01

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

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

    NARCIS (Netherlands)

    Biere, A.; Goverse, Aska

    2016-01-01

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

  6. Trapping of root-knot nematodes by the adhesive hyphae-forming fungus Arthrobotrys oligospora

    NARCIS (Netherlands)

    Belder, den E.

    1994-01-01

    The present study addresses the ecology of a particular isolate of Arthrobotrys oligospora (CBS 289.82) in relation to its efficacy in controlling the root-knot nematode, Meloidogyne hapla.

    This isolate was selected because it differs from

  7. Analysis and Characterization of Vitamin B Biosynthesis Pathways in the Phytoparasitic Nematode Heterodera Glycines

    Science.gov (United States)

    Craig, James P.

    2009-01-01

    The soybean cyst nematode (SCN), "Heterodera glycines" is an obligate plant parasite that can cause devastating crop losses. To aide in the study of this pathogen, the SCN genome and the transcriptome of second stage juveniles and eggs were shotgun sequenced. A bioinformatic screen of the data revealed nine genes involved in the "de novo"…

  8. Findings of entomopathogenic nematodes (Rhabditida, Steinernematidae) in nature reserves in Ukraine

    Czech Academy of Sciences Publication Activity Database

    Yakovlev, Ye. B.; Kharchenko, V. A.; Mráček, Zdeněk

    2014-01-01

    Roč. 48, č. 3 (2014), s. 203-210 ISSN 0084-5604 R&D Projects: GA MŠk LH12105 Institutional support: RVO:60077344 Keywords : entomopathogenic nematode Subject RIV: EH - Ecology, Behaviour http://www.degruyter.com/view/j/vzoo.2014.48.issue-3/vzoo-2014-0023/vzoo-2014-0023. xml

  9. Nematode Genera in Forest Soil Respond Differentially to Elevated CO2

    Science.gov (United States)

    Neher, Deborah A.; Weicht, Thomas R.

    2013-01-01

    Previous reports suggest that fungivorous nematodes are the only trophic group in forest soils affected by elevated CO2. However, there can be ambiguity within trophic groups, and we examined data at a genus level to determine whether the conclusion remains similar. Nematodes were extracted from roots and soil of loblolly pine (Pinus taeda) and sweet gum (Liquidambar styraciflua) forests fumigated with either ambient air or CO2-enriched air. Root length and nematode biomass were estimated using video image analysis. Most common genera included Acrobeloides, Aphelenchoides, Cephalobus, Ditylenchus, Ecphyadorphora, Filenchus, Plectus, Prismatolaimus, and Tylencholaimus. Maturity Index values and diversity increased with elevated CO2 in loblolly pine but decreased with elevated CO2 in sweet gum forests. Elevated CO2 treatment affected the occurrence of more nematode genera in sweet gum than loblolly pine forests. Numbers were similar but size of Xiphinema decreased in elevated CO2. Abundance, but not biomass, of Aphelenchoides was reduced by elevated CO2. Treatment effects were apparent at the genus levels that were masked at the trophic level. For example, bacterivores were unaffected by elevated CO2, but abundance of Cephalobus was affected by CO2 treatment in both forests. PMID:24115786

  10. A rapid, sensitive and cost-efficient assay to estimate viability of potato cyst nematodes

    NARCIS (Netherlands)

    Elsen, van den S.J.J.; Ave, M.; Schoenmakers, N.; Landeweert, R.; Bakker, J.; Helder, J.

    2012-01-01

    Potato cyst nematodes (PCN) are quarantine organisms, and they belong to the economically most relevant pathogens of potato worldwide. Methodologies to assess the viability of their cysts which can contain 200-500 eggs protected by the hardened cuticle of a dead female, are either time and labor

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  12. Epidemiology and effects of gastrointestinal nematode infection on milk productions of dairy ewes

    Directory of Open Access Journals (Sweden)

    Suarez V.H.

    2009-06-01

    Full Text Available 66 Pampinta breed ewes were studied during milking to evaluate the infection and the effect of gastrointestinal nematode on milk production sheep system. Naturally infected ewes on pasture were randomly allocated to two groups: TG, suppressively treated group every four weeks with levamisole and UG, untreated group. Faecal nematode egg counts and larval differentiation were conducted monthly. Successive groups of worm free tracer lambs were grazed with ewes and then slaughtered for worm counts. Test-day milk yield of individual ewes was recorded and ewe machine-milking period length (MPL were estimated. Faecal egg counts and tracer nematode numbers increased towards midsummer and declined sharply toward the end of the study. TG (188.0 ± 60 liters produced more (p < 0.066 milk liters than UG (171.9 ± 52.2 and TG had significantly more extended (p < 0.041 MPL than those of UG. The present study showed that dairy sheep were negatively affected by worms, even when exposed to short periods of high acute nematode (mainly Haemonchus contortus infection.

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

    NARCIS (Netherlands)

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

    2001-01-01

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

  14. Evaluation of potential bio-control agents on root-knot nematode ...

    African Journals Online (AJOL)

    Indigenous strains of Trichoderma viride (ITCC No. 6889), Pseudomonas fluorescens (ITCC No. B0034) and Purpureocillium lilacinum (ITCC No.6887) were isolated from undisturbed forest eco-system of Southern India. These three bio-mediators were evaluated for their antagonism towards root knot nematode, ...

  15. A weevil sex pheromone serves as an attractant for its entomopathogenic nematode predators

    Science.gov (United States)

    Diaprepes abbreviatus is an invasive pest of citrus in the United States originating from the Caribbean. Entomopathogenic nematodes (EPNs) are used as biological control agents in the citrus agroecosystems against D. abbreviatus. EPNs respond to herbivore-induced volatiles from citrus roots to assis...

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

    Directory of Open Access Journals (Sweden)

    Patricio Torres

    1991-03-01

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

  17. European earwig (Forficula auricularia) as a novel host for the entomopathogenic nematode Steinernema carpocapsae.

    Science.gov (United States)

    Hodson, A K; Friedman, M L; Wu, L N; Lewis, E E

    2011-05-01

    The natural history of many entomopathogenic nematode species remains unknown, despite their wide commercial availability as biological control agents. The ambushing entomopathogenic nematode, Steinernema carpocapsae, and the introduced European earwig, Forficula auricularia, forage on the soil surface. Since they likely encounter one another in nature, we hypothesized that earwigs are susceptible to nematode infection. In the laboratory, the LC(50) for F. auricularia was 226 S. carpocapsae/earwig and the reproductive potential was 123.5 infective juvenile nematodes/mg tissue. This susceptibility depended on host body size with significantly higher mortality rates seen in larger earwigs. In a study of host recognition behavior, S. carpocapsae infective juveniles responded to earwig cuticle as strongly as they did to Galleria mellonella cuticle. We also found that earwigs exposed to S. carpocapsae cleaned and scratched their front, middle and back legs significantly more than controls. Coupled with previous field data, these findings lead us to suggest that F. auricularia may be a potential host for S. carpocapsae. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. First report of the Soybean Cyst Nematode, Heterodera glycines, in New York

    Science.gov (United States)

    The soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is the most damaging pathogen of soybean (Glycine max (L.) Merr.), causing more than $1 billion in yield losses annually in the United States (Koenning and Wrather 2010). The SCN distribution map updated in 2014 showed that SCN were dete...

  19. Impact of soil nematodes on salt-marsh plants : a pilot experiment

    NARCIS (Netherlands)

    Dormann, CF; van der Wal, R

    2001-01-01

    We tested whether the removal of nematodes by means of nematicide application changed plant performance or influenced plant competition. The study involved the two common plant species Artemisia maritima and Festuca rubra growing in intact sods collected from a temperate salt marsh. Half of the sods

  20. Evaluation of potential bio-control agents on root-knot nematode ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-05-11

    May 11, 2016 ... nematode, Meloidogyne incognita and Fusarium oxysporum f.sp. conglutinans in vitro. Cell free ... are manifested by the formation of root galls accompanied by stunted growth, chlorosis and loss of viability of the plant (Babu et al., 1999). Fusarium wilt is ... effective bio-control agent on Meloidogyne spp. on.

  1. Human Pulmonary Infection by the Zoonotic Metastrongylus salmi Nematode. The First Reported Case in the Americas

    Science.gov (United States)

    Calvopina, Manuel; Caballero, Henry; Morita, Tatsushi; Korenaga, Masataka

    2016-01-01

    Pulmonary metastrongylosis, a zoonotic disease found primarily in pigs, is caused by eight different species of the cosmopolitan nematode Metastrongylus genus. To date, only four human cases have been reported, all from Europe. Herein, a severe case of pulmonary infection caused by Metastrongylus salmi in an Ecuadorian man, with successful treatment with ivermectin, is described. PMID:27382078

  2. Entomopathogenic nematodes for the control of phorid and sciarid flies in mushroom crops

    Directory of Open Access Journals (Sweden)

    María Jesús Navarro

    2014-01-01

    Full Text Available The objective of this work was to evaluate the efficacy of two nematodes, Steinernema feltiae and S. carpocapsae, to control mushroom flies and to evaluate the effect of these treatments on Agaricus bisporus production. Two mushroom cultivation trials were carried out in controlled conditions, in substrate previously infested with the diptera Megaselia halterata and Lycoriella auripila, with two treatments: 106infective juveniles (IJ per square meter of S. feltiae and 0.5x106IJ m-2S. feltiae + 0.5x106IJ m-2S. carpocapsae. Another experiment was carried out using the same treatments to evaluate the possible nematode effect on mushroom yield. The number of adults emerging from the substrate was evaluated for each fly species. No decrease in the population of M. halterata was detected with nematode application, whereas the number of L. auripila was reduced in both treatments, particularly in the individual treatment with S. feltiae. The application of entomopathogenic nematodes has no adverse effect on mushroom production.

  3. New data on the morphology of two nematode species from Caiman crocodilus from Venezuela

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Prouza, A.

    2003-01-01

    Roč. 48, č. 2 (2003), s. 111-118 ISSN 1230-2821 R&D Projects: GA AV ČR IAA6022201 Institutional research plan: CEZ:AV0Z6022909 Keywords : parasitic nematodes * Brevimulticaecum * Micropleura Subject RIV: EA - Cell Biology Impact factor: 0.495, year: 2003

  4. A framework for soil food web diagnostics : extension of the nematode faunal analysis concept

    NARCIS (Netherlands)

    Ferris, H.; Bongers, T.; Goede, de R.G.M.

    2001-01-01

    Nematodes, the earth's most abundant metazoa, are ubiquitous in the soil environment. They are sufficiently large to be identifiable by light microscopy and sufficiently small to inhabit water films surrounding soil particles. They aggregate around and in food sources. They include component taxa of

  5. Fungal root endophytes of tomato from Kenya and their nematode biocontrol potential

    NARCIS (Netherlands)

    Bogner, C.W.; Kariuki, George M.; Elashry, A.; Sichtermann, Gisela; Buch, Ann-Katrin; Mishra, Bagdevi; Thines, M.; Grundler, F.M.W.; Schouten, A.

    2016-01-01

    The significance of fungal endophytes in African agriculture, particularly Kenya, has not been well investigated. Therefore, the objective of the present work was isolation, multi-gene phylogenetic characterization and biocontrol assessment of endophytic fungi harbored in tomato roots for nematode

  6. Possible mechanisms underlying abundance and diversity responses of nematode communities to plant diversity

    NARCIS (Netherlands)

    Cortois, R.; Veen, G.F.; Duyts, Henk; Abbas, Maike; Strecker, Tanja; Kostenko, Olga; Eisenhauer, Nico; Scheu, Stefan; Gleixner, Gerd; Deyn, De Gerlinde B.; Putten, van der Wim H.

    2017-01-01

    Plant diversity is known to influence the abundance and diversity of belowground biota; however, patterns are not well predictable and there is still much unknown about the driving mechanisms. We analyzed changes in soil nematode community composition as affected by long-term manipulations of

  7. Possible mechanisms underlying abundance and diversity responses of nematode communities to plant diversity

    NARCIS (Netherlands)

    Cortois, R.; Veen, G.F.; Duyts, H.; Abbas, M.; Strecker, T; Kostenko, O.; Eisenhauer, Nico; Scheu, S.; Gleixner, G.; De Deyn, G.B.; van der Putten, W.H.

    2017-01-01

    Plant diversity is known to influence the abundance and diversity of belowground biota; however, patterns are not well predictable and there is still much unknown about the driving mechanisms. We analyzed changes in soil nematode community composition as affected by long-term manipulations of plant

  8. Field performance of Solanum sisymbriifolium, a trap crop for potato cyst nematodes. II. Root characteristics

    NARCIS (Netherlands)

    Timmermans, B.G.H.; Vos, J.; Stomph, T.J.; Nieuwburg, van J.G.W.; Putten, van der P.E.L.

    2007-01-01

    Hatching of potato cyst nematodes is induced by root exudates of Solanaceae, such as Solanum sisymbriifolium, and is therefore related to root length distribution of this crop. A mathematical model was derived to relate the hatching potential to root length density (RLD). A series of field

  9. A new atractid nematode, Atractis vidali sp. n. (Nematoda: Atractidae), from cichlid fishes in southern Mexico

    Czech Academy of Sciences Publication Activity Database

    González-Solís, D.; Moravec, František

    2002-01-01

    Roč. 49, č. 3 (2002), s. 227-230 ISSN 0015-5683 R&D Projects: GA AV ČR IAA6022901 Institutional research plan: CEZ:AV0Z6022909 Keywords : parasitic nematode * freshwater fishes * Atractis vidali Subject RIV: EG - Zoology Impact factor: 0.515, year: 2002

  10. Economic modelling of grazing management against gastrointestinal nematodes in dairy cattle

    NARCIS (Netherlands)

    Voort, van der M.; Meensel, Van J.; Lauwers, L.; Haan, de M.H.A.; Evers, A.G.; Huylenbroeck, Van G.; Charlier, J.

    2017-01-01

    Grazing management (GM) interventions, such as reducing the grazing time or mowing pasture before grazing, have been proposed to limit the exposure to gastrointestinal (GI) nematode infections in grazed livestock. However, the farm-level economic effects of these interventions have not yet been

  11. Seasonal distribution of gastrointestinal nematode infections in sheep in a semiarid region, northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Maria de Fátima de Souza

    Full Text Available The objective of this study was to determine the seasonal distribution and gastrointestinal nematode parasite load in crossbred Santa Inês tracer lambs, and to correlate the rainfall during the study period with occurrences of parasitic infections. Sixty-four male tracer lambs between the ages of four and eight months were used in the study. Two tracer lambs were inserted into the herd every 28 days to determine the pattern of infective larvae available in the environment. Variation in the fecal egg count (FEC of nematodes was observed at the study site, with many samples containing undetectable parasite loads during the dry season. The larvae identified in coprocultures wereHaemonchus sp., Trichostrongylus sp.,Cooperia sp., Strongyloides sp. andOesophagostomum sp. The nematodes recovered at necropsy were Haemonchus contortus, Trichostrongylus colubriformis, Cooperia punctata, C. pectinata, Trichuris sp.,Oesophagostomum sp. and Skrajabinema ovis. The total number of larvae and the total number of immature and adult forms recovered from the tracers showed seasonal distributions that significantly correlated with the amount of rainfall received that month (p value ≅ 0.000 in all cases . The species H. contortus was predominant in the herd and should be considered to be main pathogenic nematode species in these hosts under these conditions.

  12. Effect of nematode infections on productivity of young and adult cattle on commercial dairy farms

    NARCIS (Netherlands)

    Ploeger, H.W.

    1989-01-01

    In this study relationships between levels of exposure to gastrointestinal and lung nematode infections and production were investigated on commercial dairy farms in the Netherlands. Little was known about these

    relationships, particularly with respect to second-year cattle and

  13. Urbanization alters the functional composition, but not taxonomic diversity, of the soil nematode community

    Science.gov (United States)

    Mitchell A. Pavao-Zuckerman; David C. Coleman

    2007-01-01

    We evaluated the response of riparian forest soil nematode community structure to the physico-chemical environment associated with urban land use. Soils were sampled seasonally between December 2000 and October 2002 along an urban-rural transect in Asheville, North Carolina. We characterized the taxonomic (to genus) and functional composition (trophic groups) of the...

  14. A Plant-Feeding Nematode Indirectly Increases the Fitness of an Aphid

    Directory of Open Access Journals (Sweden)

    Grace A. Hoysted

    2017-11-01

    Full Text Available Plants suffer multiple, simultaneous assaults from above and below ground. In the laboratory, pests and/or pathogen attack are commonly studied on an individual basis. The molecular response of the plant to attack from multiple organisms and the interaction of different defense pathways is unclear. The inducible systemic responses of the potato (Solanum tuberosum L. host plant were analyzed to characterize the plant-mediated indirect interactions between a sedentary, endoparasitic nematode (Globodera pallida, and a phloem-sucking herbivore (Myzus persicae. The reproductive success of M. persicae was greater on potato plants pre-infected with G. pallida compared to control plants. Salicylic acid (SA increased systemically in the leaves of potato plants following nematode and aphid infection singly with a corresponding increase in expression of SA-mediated marker genes. An increase in jasmonic acid associated with aphid infection was suppressed when plants were co-infected with nematodes. Our data suggests a positive, asymmetric interaction between a sedentary endoparasitic nematode and a sap-sucking insect. The systemic response of the potato plant following infection with G. pallida indirectly influences the performance of M. persicae. This work reveals additional secondary benefits of controlling individual crop pests.

  15. Covering ground: insights into soil ecology by molecular monitoring of nematode assemblages

    NARCIS (Netherlands)

    Vervoort, M.T.W.

    2013-01-01

    Soil performs numerous functions, which allow us to produce food and feed and provide us with clean freshwater. These functions rely on the high diversity of organisms residing in soils. Within the high complexity of the soil food web, nematodes, worm-shaped animals belonging to the phylum

  16. Natural variation in dauer pheromone production and sensing supports intraspecific competition in nematodes.

    Science.gov (United States)

    Bose, Neelanjan; Meyer, Jan M; Yim, Joshua J; Mayer, Melanie G; Markov, Gabriel V; Ogawa, Akira; Schroeder, Frank C; Sommer, Ralf J

    2014-07-07

    Dauer formation, a major nematode survival strategy, represents a model for small-molecule regulation of metazoan development [1-10]. Free-living nematodes excrete dauer-inducing pheromones that have been assumed to target conspecifics of the same genotype [9, 11]. However, recent studies in Pristionchus pacificus revealed that the dauer pheromone of some strains affects conspecifics of other genotypes more strongly than individuals of the same genotype [12]. To elucidate the mechanistic basis for this intriguing cross-preference, we compared six P. pacificus wild isolates to determine the chemical composition of their dauer-inducing metabolomes and responses to individual pheromone components. We found that these isolates produce dauer pheromone blends of different composition and respond differently to individual pheromone components. Strikingly, there is no correlation between production of and dauer response to a specific compound in individual strains. Specifically, pheromone components that are abundantly produced by one genotype induce dauer formation in other genotypes, but not necessarily in the abundant producer. Furthermore, some genotypes respond to pheromone components they do not produce themselves. These results support a model of intraspecific competition in nematode dauer formation. Indeed, we observed intraspecific competition among sympatric strains in a novel experimental assay, suggesting a new role of small molecules in nematode ecology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Field resistance of transgenic plantain to nematodes has potential for future African food security.

    Science.gov (United States)

    Tripathi, Leena; Babirye, Annet; Roderick, Hugh; Tripathi, Jaindra N; Changa, Charles; Urwin, Peter E; Tushemereirwe, Wilberforce K; Coyne, Danny; Atkinson, Howard J

    2015-01-30

    Plant parasitic nematodes impose losses of up to 70% on plantains and cooking bananas in Africa. Application of nematicides is inappropriate and resistant cultivars are unavailable. Where grown, demand for plantain is more than for other staple crops. Confined field testing demonstrated that transgenic expression of a biosafe, anti-feedant cysteine proteinase inhibitor and an anti-root invasion, non-lethal synthetic peptide confers resistance to plantain against the key nematode pests Radopholus similis and Helicotylenchus multicinctus. The best peptide transgenic line showed improved agronomic performance relative to non-transgenic controls and provided about 99% nematode resistance at harvest of the mother crop. Its yield was about 186% in comparison with the nematode challenged control non-transgenic plants based on larger bunches and diminished plant toppling in storms, due to less root damage. This is strong evidence for utilizing this resistance to support the future food security of 70 million, mainly poor Africans that depend upon plantain as a staple food.

  18. Steinernema biddulphi n. sp., a new entomopathogenic nematode (Nematoda: Steinernematidae) from South Africa

    Czech Academy of Sciences Publication Activity Database

    Çimen, H.; Půža, Vladimír; Nermuť, Jiří; Hatting, J.; Ramakuwela, T.; Hazir, S.

    2016-01-01

    Roč. 48, č. 3 (2016), s. 148-158 ISSN 0022-300X R&D Projects: GA MŠk LH12105 Institutional support: RVO:60077344 Keywords : D2-D3 * entomopathogenic nematodes * ITS Subject RIV: EG - Zoology Impact factor: 1.087, year: 2016 http://journals.fcla.edu/jon/issue/view/4275

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

    Science.gov (United States)

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

  20. powdery leaf extracts for control of root knot nematode in african ...

    African Journals Online (AJOL)

    journal

    POWDERY LEAF EXTRACTS FOR CONTROL OF ROOT KNOT NEMATODE IN. AFRICAN YAM BEAN. K.I. UGWUOKE, B.O. UKWUEZE and S.I. OGWULUMBA1. Department of Crop Science, University of Nigeria, Nsukka,Nigeria. 1Department of Crop Production Technology, Federal College of Agriculture Ishiagu, Nigeria.