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Sample records for filarial nematode brugia

  1. Heme acquisition in the parasitic filarial nematode Brugia malayi

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2007-09-21

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

  3. Heat shock and developmental expression of hsp83 in the filarial nematode Brugia pahangi.

    PubMed

    Thompson, F J; Cockroft, A C; Wheatley, I; Britton, C; Devaney, E

    2001-11-01

    hsp83 was cloned from the filarial nematode Brugia pahangi. The mRNA was constitutively expressed at 37 degrees C in life cycle stages that live in the mammalian host (microfilariae and adult worms). Heat shock resulted in only a minimal increase in levels of transcription. A genomic copy of hsp83 was isolated and was shown to contain 11 introns while sequencing of the 5' upstream region revealed several heat shock elements. Using a chloramphenicol acetyltransferase (CAT) reporter gene construct the expression of hsp83 from B. pahangi (Bp-hsp83) was studied by transfection of COS-7 cells. Similar to the expression pattern in the parasite, CAT activity was detected at 37 degrees C and was not influenced by heat shock. When the free-living nematode Caenorhabditis elegans was transfected with the same construct, CAT activity was not observed at normal growth temperatures (21 degrees C) or under moderate heat shock conditions (28 degrees C). However exposure to more severe heat shock (35 degrees C) resulted in an increase in CAT activity. These results suggest that Bp-hsp83 has a temperature threshold > or = 35 degrees C for expression.

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

    SciTech Connect

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

    1993-02-15

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

  5. Development of an In Vivo RNAi Protocol to Investigate Gene Function in the Filarial Nematode, Brugia malayi

    PubMed Central

    Song, Chuanzhe; Gallup, Jack M.; Day, Tim A.

    2010-01-01

    Our ability to control diseases caused by parasitic nematodes is constrained by a limited portfolio of effective drugs and a paucity of robust tools to investigate parasitic nematode biology. RNA interference (RNAi) is a reverse-genetics tool with great potential to identify novel drug targets and interrogate parasite gene function, but present RNAi protocols for parasitic nematodes, which remove the parasite from the host and execute RNAi in vitro, are unreliable and inconsistent. We have established an alternative in vivo RNAi protocol targeting the filarial nematode Brugia malayi as it develops in an intermediate host, the mosquito Aedes aegypti. Injection of worm-derived short interfering RNA (siRNA) and double stranded RNA (dsRNA) into parasitized mosquitoes elicits suppression of B. malayi target gene transcript abundance in a concentration-dependent fashion. The suppression of this gene, a cathepsin L-like cysteine protease (Bm-cpl-1) is specific and profound, both injection of siRNA and dsRNA reduce transcript abundance by 83%. In vivo Bm-cpl-1 suppression results in multiple aberrant phenotypes; worm motility is inhibited by up to 69% and parasites exhibit slow-moving, kinked and partial-paralysis postures. Bm-cpl-1 suppression also retards worm growth by 48%. Bm-cpl-1 suppression ultimately prevents parasite development within the mosquito and effectively abolishes transmission potential because parasites do not migrate to the head and proboscis. Finally, Bm-cpl-1 suppression decreases parasite burden and increases mosquito survival. This is the first demonstration of in vivo RNAi in animal parasitic nematodes and results indicate this protocol is more effective than existing in vitro RNAi methods. The potential of this new protocol to investigate parasitic nematode biology and to identify and validate novel anthelmintic drug targets is discussed. PMID:21203489

  6. Differential transcript expression between the microfilariae of the filarial nematodes, Brugia malayi and B. pahangi

    PubMed Central

    2010-01-01

    Background Brugia malayi and B. pahangi are two closely related nematodes that cause filariasis in humans and animals. However, B. pahangi microfilariae are able to develop in and be transmitted by the mosquito, Armigeres subalbatus, whereas most B. malayi are rapidly melanized and destroyed within the mosquito hemocoel. A cross-species microarray analysis employing the B. malayi V2 array was carried out to determine the transcriptional differences between B. malayi and B. pahangi microfilariae with similar age distribution. Results Following microarray data analysis, a list of preferentially expressed genes in both microfilariae species was generated with a false discovery rate estimate of 5% and a signal intensity ratio of 2 or higher in either species. A total of 308 probes were preferentially expressed in both species with 149 probes, representing 123 genes, in B. pahangi microfilariae and 159 probes, representing 107 genes, in B. malayi microfilariae. In B. pahangi, there were 76 (62%) up-regulated transcripts that coded for known proteins that mapped into the KEGG pathway compared to 61 (57%) transcripts in B. malayi microfilariae. The remaining 47 (38%) transcripts in B. pahangi and 46 (43%) transcripts in B. malayi microfilariae were comprised almost entirely of hypothetical genes of unknown function. Twenty-seven of the transcripts in B. pahangi microfilariae coded for proteins that associate with the secretory pathway compared to thirty-nine in B. malayi microfilariae. The data obtained from real-time PCR analysis of ten genes selected from the microarray list of preferentially expressed genes showed good concordance with the microarray data, indicating that the microarray data were reproducible. Conclusion In this study, we identified gene transcripts that were preferentially expressed in the microfilariae of B. pahangi and B. malayi, some of which coded for known immunomodulatory proteins. These comparative transcriptome data will be of interest to

  7. Identification of tgh-2, a Filarial Nematode Homolog of Caenorhabditis elegans daf-7 and Human Transforming Growth Factor β, Expressed in Microfilarial and Adult Stages of Brugia malayi

    PubMed Central

    Gomez-Escobar, Natalia; Gregory, William F.; Maizels, Rick M.

    2000-01-01

    A novel member of the transforming growth factor β (TGF-β) family has been identified in the filarial nematode parasite Brugia malayi by searching the recently developed Expressed Sequence Tag (EST) database produced by the Filarial Genome Project. Designated tgh-2, this new gene shows most similarity to a key product regulating dauer larva formation in Caenorhabditis elegans (DAF-7) and to the human down-modulatory cytokine TGF-β. Homology to DAF-7 extends throughout the length of the 349-amino-acid (aa) protein, which is divided into an N-terminal 237 aa, including a putative signal sequence, a 4-aa basic cleavage site, and a 108-aa C-terminal active domain. Similarity to human TGF-β is restricted to the C-terminal domain, over which there is a 32% identity between TGH-2 and TGF-β1, including every cysteine residue. Expression of tgh-2 mRNA has been measured over the filarial life cycle. It is maximal in the microfilarial stage, with lower levels of activity around the time of molting within the mammal, but continues to be expressed by mature adult male and female parasites. Expression in both the microfilaria, which is in a state of arrested development, and the adult, which is terminally differentiated, indicates that tgh-2 may play a role other than purely developmental. This is consistent with our observation that TGH-2 is secreted by adult worms in vitro. Recombinant TGH-2 expressed in baculovirus shows a low level of binding to TGF-β-receptor bearing mink lung epithelial cells (MELCs), which is partially inhibited (16 to 39%) with human TGF-β, and activates plasminogen activator inhibitor-1 transcription in MELCs, a marker for TGF-β-mediated transduction. Further tests will be required to establish whether the major role of B. malayi TGH-2 (Bm-TGH-2) is to modulate the host immune response via the TGF-β pathway. PMID:11035752

  8. Attempts to Image the Early Inflammatory Response during Infection with the Lymphatic Filarial Nematode Brugia pahangi in a Mouse Model

    PubMed Central

    Ritchie, Ryan; Goundry, Amy; O’Neill, Kerry; Marchesi, Francesco; Devaney, Eileen

    2016-01-01

    Helminth parasites remain a major constraint upon human health and well-being in many parts of the world. Treatment of these infections relies upon a very small number of therapeutics, most of which were originally developed for use in animal health. A lack of high throughput screening systems, together with limitations of available animal models, has restricted the development of novel chemotherapeutics. This is particularly so for filarial nematodes, which are long-lived parasites with a complex cycle of development. In this paper, we describe attempts to visualise the immune response elicited by filarial parasites in infected mice using a non-invasive bioluminescence imaging reagent, luminol, our aim being to determine whether such a model could be developed to discriminate between live and dead worms for in vivo compound screening. We show that while imaging can detect the immune response elicited by early stages of infection with L3, it was unable to detect the presence of adult worms or, indeed, later stages of infection with L3, despite the presence of worms within the lymphatic system of infected animals. In the future, more specific reagents that detect secreted products of adult worms may be required for developing screens based upon live imaging of infected animals. PMID:27992545

  9. The Wolbachia endosymbiont as an anti-filarial nematode target

    PubMed Central

    Taylor, Mark J.; Foster, Jeremy M.

    2010-01-01

    Human disease caused by parasitic filarial nematodes is a major cause of global morbidity. The parasites are transmitted by arthropod intermediate hosts and are responsible for lymphatic filariasis (elephantiasis) or onchocerciasis (river blindness). Within these filarial parasites are intracellular alpha-proteobacteria, Wolbachia, that were first observed almost 30 years ago. The obligate endosymbiont has been recognized as a target for anti-filarial nematode chemotherapy as evidenced by the loss of worm fertility and viability upon antibiotic treatment in an extensive series of human trials. While current treatments with doxycycline and rifampicin are not practical for widespread use due to the length of required treatments and contraindications, anti-Wolbachia targeting nevertheless appears a promising alternative for filariasis control in situations where current programmatic strategies fail or are unable to be delivered and it provides a superior efficacy for individual therapy. The mechanisms that underlie the symbiotic relationship between Wolbachia and its nematode hosts remain elusive. Comparative genomics, bioinfomatic and experimental analyses have identified a number of potential interactions, which may be drug targets. One candidate is de novo heme biosynthesis, due to its absence in the genome sequence of the host nematode, Brugia malayi, but presence in Wolbachia and its potential roles in worm biology. We describe this and several additional candidate targets, as well as our approaches for understanding the nature of the host-symbiont relationship. PMID:20730111

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

    PubMed Central

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

    2015-01-01

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

  11. Characterization of innate immunity genes in the parasitic nematode Brugia malayi.

    PubMed

    Libro, Silvia; Slatko, Barton E; Foster, Jeremy M

    The filarial nematode Brugia malayi is one of the causative agents of lymphatic filariasis, a neglected tropical disease that affects 120 million people worldwide. The limited effectiveness of available anthelmintics and the absence of a vaccine have prompted extensive research on the interaction between Brugia and its obligate bacterial endosymbiont, Wolbachia. Recent studies suggest that Wolbachia is able to manipulate its nematode host immunity but relatively little is known about the immune system of filarial nematodes. Therefore, elucidation of the mechanisms underlying the immune system of B. malayi may be useful for understanding how the symbiotic relationship is maintained and help in the identification of new drug targets. In order to characterize the main genetic pathways involved in B. malayi immunity, we exposed adult female worms to two bacterial lysates (Escherichia coli and Bacillus amyloliquefaciens), dsRNA and dsDNA. We performed transcriptome sequencing of worms exposed to each immune elicitor at two different timepoints. Gene expression analysis of untreated and immune-challenged worms was performed to characterize gene expression patterns associated with each type of immune stimulation. Our results indicate that different immune elicitors produced distinct expression patterns in B. malayi, with changes in the expression of orthologs of well-characterized C. elegans immune pathways such as insulin, TGF-β, and p38 MAPK pathways, as well as C-type lectins and several stress-response genes.

  12. Molecular epidemiology, phylogeny and evolution of the filarial nematode Wuchereria bancrofti.

    PubMed

    Small, Scott T; Tisch, Daniel J; Zimmerman, Peter A

    2014-12-01

    Wuchereria bancrofti (Wb) is the most widely distributed of the three nematodes known to cause lymphatic filariasis (LF), the other two being Brugia malayi and Brugia timori. Current tools available to monitor LF are limited to diagnostic tests targeting DNA repeats, filarial antigens, and anti-filarial antibodies. While these tools are useful for detection and surveillance, elimination programs have yet to take full advantage of molecular typing for inferring infection history, strain fingerprinting, and evolution. To date, molecular typing approaches have included whole mitochondrial genomes, genotyping, targeted sequencing, and random amplified polymorphic DNA (RAPDs). These studies have revealed much about Wb biology. For example, in one study in Papua New Guinea researchers identified 5 major strains that were widespread and many minor strains some of which exhibit geographic stratification. Genome data, while rare, has been utilized to reconstruct evolutionary relationships among taxa of the Onchocercidae (the clade of filarial nematodes) and identify gene synteny. Their phylogeny reveals that speciation from the common ancestor of both B. malayi and Wb occurred around 5-6 millions years ago with shared ancestry to other filarial nematodes as recent as 15 million years ago. These discoveries hold promise for gene discovery and identifying drug targets in species that are more amenable to in vivo experiments. Continued technological developments in whole genome sequencing and data analysis will likely replace many other forms of molecular typing, multiplying the amount of data available on population structure, genetic diversity, and phylogenetics. Once widely available, the addition of population genetic data from genomic studies should hasten the elimination of LF parasites like Wb. Infectious disease control programs have benefited greatly from population genetics data and recently from population genomics data. However, while there is currently a surplus

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

    PubMed

    Wu, Bo; Novelli, Jacopo; Foster, Jeremy; Vaisvila, Romualdas; Conway, Leslie; Ingram, Jessica; Ganatra, Mehul; Rao, Anita U; Hamza, Iqbal; Slatko, Barton

    2009-07-14

    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'-aminolevulinic acid

  14. Molecular epidemiology, phylogeny and evolution of the filarial nematode Wuchereria bancrofti

    PubMed Central

    Small, Scott T.; Tisch, Daniel J.; Zimmerman, Peter A.

    2014-01-01

    Wuchereria bancrofti (Wb) is the most widely distributed of the three nematodes known to cause lymphatic filariasis (LF), the other two being Brugia malayi and B. timori. Current tools available to monitor LF are limited to diagnostic tests targeting DNA repeats, filarial antigens, and anti-filarial antibodies. While these tools are useful for detection and surveillance, elimination programs have yet to take full advantage of molecular typing for inferring infection history, strain fingerprinting, and evolution. To date, molecular typing approaches have included whole mitochondrial genomes, genotyping, targeted sequencing, and random amplified polymorphic DNA (RAPDs). These studies have revealed much about Wb biology. For example, in one study in Papua New Guinea researchers identified 5 major strains that were widespread and many minor strains some of which exhibit geographic stratification. Genome data, while rare, has been utilized to reconstruct evolutionary relationships among taxa of the Onchocercidae (the clade of filarial nematodes) and identify gene synteny. Their phylogeny reveals that speciation from the common ancestor of both B. malayi and Wb occurred around 5–6 millions years ago with shared ancestry to other filarial nematodes as recent as 15 million years ago. These discoveries hold promise for gene discovery and identifying drug targets in species that are more amenable to in vivo experiments. Continued technological developments in whole genome sequencing and data analysis will likely replace many other forms of molecular typing, multiplying the amount of data available on population structure, genetic diversity, and phylogenetics. Once widely available, the addition of population genetic data from genomic studies should hasten the elimination of LF parasites like Wb. PMID:25176600

  15. Use of Iodogen and sulfosuccinimidobiotin to identify and isolate cuticular proteins of the filarial parasite Brugia malayi.

    PubMed

    Alvarez, R M; Henry, R W; Weil, G J

    1989-03-01

    The cuticle of filarial nematodes is a dynamic structure which may be an important target for protective host immune responses. Prior studies have employed radioiodination of intact parasites to demonstrate that the collagenous cuticle of filariids contains relatively few exposed proteins, some of which are stage and/or species-specific. In the present study, we have used sulfo-NHS-biotin to label and affinity purify cuticular components of living adult Brugia malayi. Results obtained by this method were compared with the widely used Iodogen method of surface radioiodination by SDS-PAGE analysis of detergent-solubilized worms and by ultrastructural analysis. Both labeling methods produced very similar electrophoretic patterns with major doublets at 70 and 100 kDa, a major band at 25 kDa, and minor bands between 60-200 kDa. Ultrastructural analysis showed that both methods labeled components throughout all levels of the parasite cuticle; underlying somatic tissues were not labeled. The biotinylated components were isolated from the total parasite extract by affinity chromatography on an avidin matrix. Further characterization of these surface-associated proteins may lead to improved methods for the control of filariasis.

  16. Crystal structure of the cyclophilin-like domain from the parasitic nematode Brugia malayi.

    PubMed Central

    Mikol, V.; Ma, D.; Carlow, C. K.

    1998-01-01

    Cyclophilins are a family of proteins that exhibit peptidyl-prolyl cis-trans isomerase activity and bind the immunosuppressive agent cyclosporin A (CsA). Brugia malayi is a filarial nematode parasite of humans, for which a cyclophilin-like domain was identified at the N-terminal of a protein containing 843 amino acid residues. There are two differences in sequence in the highly conserved CsA binding site: A histidine and a lysine replace a tryptophan and an alanine, respectively. The crystal structure of this domain has been determined by the molecular replacement method and refined to an R-factor of 16.9% at 2.15 A resolution. The overall structure is similar to other cyclophilins; however, major differences occur in two loops. Comparison of the CsA binding site of this domain with members of the cyclophilin family shows significant structural differences, which can account for the reduced sensitivity of the Brugia malayi protein to inhibition by CsA. PMID:9655334

  17. How do the macrocyclic lactones kill filarial nematode larvae?

    PubMed Central

    Wolstenholme, Adrian J.; Maclean, Mary J.; Coates, Ruby; McCoy, Ciaran J.; Reaves, Barbara J.

    2017-01-01

    The macrocyclic lactones (MLs) are one of the few classes of drug used in the control of the human filarial infections, onchocerciasis and lymphatic filariasis, and the only one used to prevent heartworm disease in dogs and cats. Despite their importance in preventing filarial diseases, the way in which the MLs work against these parasites is unclear. In vitro measurements of nematode motility have revealed a large discrepancy between the maximum plasma concentrations achieved after drug administration and the amounts required to paralyze worms. Recent evidence has shed new light on the likely functions of the ML target, glutamate-gated chloride channels, in filarial nematodes and supports the hypothesis that the rapid clearance of microfilariae that follows treatment involves the host immune system. PMID:27279086

  18. How do the macrocyclic lactones kill filarial nematode larvae?

    PubMed

    Wolstenholme, Adrian J; Maclean, Mary J; Coates, Ruby; McCoy, Ciaran J; Reaves, Barbara J

    2016-09-01

    The macrocyclic lactones (MLs) are one of the few classes of drug used in the control of the human filarial infections, onchocerciasis and lymphatic filariasis, and the only one used to prevent heartworm disease in dogs and cats. Despite their importance in preventing filarial diseases, the way in which the MLs work against these parasites is unclear. In vitro measurements of nematode motility have revealed a large discrepancy between the maximum plasma concentrations achieved after drug administration and the amounts required to paralyze worms. Recent evidence has shed new light on the likely functions of the ML target, glutamate-gated chloride channels, in filarial nematodes and supports the hypothesis that the rapid clearance of microfilariae that follows treatment involves the host immune system.

  19. Molecular identification of Wolbachia from the filarial nematode Mansonella perstans

    PubMed Central

    Keiser, Paul B.; Coulibaly, Yaya; Kubofcik, Joseph; Diallo, Abdallah A.; Klion, Amy D.; Traoré, Sekou F.; Nutman, Thomas B.

    2008-01-01

    Wolbachiae are bacterial endosymbionts of insects and many filarial nematodes whose products trigger inflammation in filarial infections. The dependence of the parasites on their endosymbionts has also led to the use of antibiotics directed against the Wolbachiae, therapy that has been demonstrated to have a profound salutary effect on filarial infections. The identification of Wolbachiae in Mansonella species has been conclusively shown for Mansonella ozzardi (Mo), but not for Mansonella perstans (Mp) Using primers known to amplify the 16S ribosomal DNA of other filarial Wolbachiae, an identical 1393 bp band was found in all samples tested. Sequence analysis of these samples demonstrated a single consensus sequence for Mp Wolbachia 16S rDNA that was most similar to Wolbachia sequences from other filarial nematodes. When aligned with the only other Mansonella Wolbachia sequence (Mo) there were only 8 nucleotide differences in the 1369 bp overlapping sequence. Phylogenetic dendrograms, showing the relationship of the Mp Wolbachia to other Wolbachia 16S rDNA, tracked almost identically to the 5S rRNA of their parasite host. Wolbachia surface protein (WSP) was also demonstrated in protein extracted from Mp-containing whole blood. In advance of a treatment trial of Mp, a method for the quantitation of Mp Wolbachia was developed and used to demonstrate not only a relationship between microfilarial numbers and Wolbachia copy numbers, but also to demonstrate the effect of antibiotic on ridding Mp of Wolbachia. PMID:18538871

  20. A Deep Sequencing Approach to Comparatively Analyze the Transcriptome of Lifecycle Stages of the Filarial Worm, Brugia malayi

    PubMed Central

    Choi, Young-Jun; Ghedin, Elodie; Berriman, Matthew; McQuillan, Jacqueline; Holroyd, Nancy; Mayhew, George F.; Christensen, Bruce M.; Michalski, Michelle L.

    2011-01-01

    Background 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. Methodology/Principal Findings 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. Conclusions/Significance 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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  3. Cloning, expression, purification and kinetics of trehalose-6-phosphate phosphatase of filarial parasite Brugia malayi.

    PubMed

    Kushwaha, Susheela; Singh, Prashant K; Rana, Ajay K; Misra-Bhattacharya, Shailja

    2011-08-01

    The pleiotropic functions of disaccharide trehalose in the biology of nematodes and its absence from mammalian cells suggest that its biosynthesis may provide a useful target for developing novel nematicidal drugs. The trehalose-6-phosphate phosphatase (TPP), one of the enzymes of trehalose metabolism has not been characterized so far in nematodes except the free living nematode Caenorhabditis elegans where it's silencing results into lethal outcomes. This prompted us to clone and characterize Brugia malayi TPP in order to discover novel antifilarial drug target. The recombinant protein (Bm-TPP) was purified with apparent homogeneity on a metal ion column and it was found to possess high phosphatase activity with robust specificity for the substrate trehalose-6-phosphate. Bm-TPP was found to be a member of the HAD-like hydrolase super family II based on the conserved motifs required for catalytic reaction. The K(m) for substrate trehalose-6-phosphate was around 0.42 mM with pH optimum ∼7.0 and the enzyme showed an almost absolute requirement for Mg(2+) as a metal ion. Bm-TPP was expressed in all the life-stages of B. malayi. In the absence of an effective macrofilaricidal agent and validated antifilarial drug target, Bm-TPP bodes well as a rational drug target against lymphatic filariasis.

  4. High level expression of a glutamate-gated chloride channel gene in reproductive tissues of Brugia malayi may explain the sterilizing effect of ivermectin on filarial worms☆

    PubMed Central

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

    2014-01-01

    Glutamate-gated chloride channels (GluCl) are targets for avermectin/milbemycin (A/M) anthelmintics such as ivermectin that cause paralysis of somatic and pharyngeal muscles in gastrointestinal nematodes. Ivermectin is useful for onchocerciasis control programs because of its activity against microfilariae that often cause ocular disease and severe dermatitis. However, mechanisms responsible for reduced microfilaria production by adult worms following ivermectin treatment are poorly understood. We synthesized subunit-specific RNA probes for the Brugia malayi GluCl gene avr-14 (BmAVR-14) to localize expression of this gene in adult filarial worms. Both subunits of BmAVR-14 exhibited very similar expression patterns. In female worms, strong expression signals were detected in the ovary, developing embryos and lateral hypodermal chords, with moderate expression in the uterus wall adjacent to stretched microfilariae. These genes were also highly expressed in adult male worms (in spermatogonia, in the wall of the vas deferens, and in the lateral chords, but not in mature spermatozoa). In addition, avr-14 was highly expressed in somatic muscles adjacent to the terminal end of the vas deferens which contains mature sperm. These results show that avr-14 is highly expressed in B. malayi developing embryos and reproductive tissues, and they provide evidence for the involvement of GluCl in gamete production and embryogenesis in filarial worms. This may explain the observed suppression of microfilaria (Mf) production by female worms following treatment with avermectin/milbemycin anthelmintics. PMID:25057456

  5. "Filarial dance sign" real-time ultrasound diagnosis of filarial oophoritis.

    PubMed

    Panditi, Surekha; Shelke, Ashwini G; Thummalakunta, Laxmi Narasimha Praveen

    2016-10-01

    Filariasis is a parasitic disease caused by Filarial nematodes (Wuchereria bancrofti, Brugia malayi, and Brugia timori) that commonly causes lymphatic obstruction resulting in edema and increase in the size of the affected organ. Filariasis is diagnosed by identifying microfilariae on Giemsa stain. The immunochromatographic card test is diagnostic. Ultrasound is the imaging modality of choice for detecting adult filarial worms/microfilaria in the lymphatic system, which are responsible for the classic "filarial dance sign" caused by twirling movements of the microfilariae. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:500-501, 2016. © 2016 Wiley Periodicals, Inc.

  6. Pyrosequencing Using SL and 5S rRNA as Molecular Markers for Identifying Zoonotic Filarial Nematodes in Blood Samples and Mosquitoes.

    PubMed

    Sanpool, Oranuch; Tantrawatpan, Chairat; Thanchomnang, Tongjit; Janwan, Penchom; Intapan, Pewpan M; Rodpai, Rutchanee; Lulitanond, Viraphong; Taweethavonsawat, Piyanan; Maleewong, Wanchai

    2016-05-01

    Lymphatic filariasis is principally caused by Wuchereria bancrofti, and Brugia malayi. The other two filarial nematode species, Brugia pahangi and Dirofilaria immitis, possibly cause human zoonotic diseases. We propose the development of a PCR assay linked with DNA pyrosequencing as a rapid tool to identify W. bancrofti, B. malayi, B. pahangi, and D. immitis in blood samples and mosquitoes. Primers targeting the fragment of the 5S ribosomal RNA and spliced leader sequences were newly designed and developed to identify these four filarial nematodes. Analytical sensitivity and specificity were evaluated. Pyrosequencing determination of nucleotide variations within 36 nucleotides for B. malayi and B. pahangi, and 32 nucleotides for W. bancrofti and D. immitis is sufficient for differentiation of those filarial nematodes, and for detection of intraspecies genetic variation of B. malayi. This analysis could detect a single B. malayi, B. pahangi, W. bancrofti, and D. immitis microfilaria in blood samples. Overall, the PCR-linked pyrosequencing-based method was faster than direct sequencing and less expensive than real-time PCR or direct sequencing. This is the possibility of choice that can be applied in a high-throughput platform for identification and surveillance of reservoirs and vectors infected with lymphatic filaria in endemic areas.

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

    PubMed

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

    2014-12-01

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

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

    PubMed

    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.

  9. Vector competence of Aedes aegypti mosquitoes for filarial nematodes is affected by age and nutrient limitation.

    PubMed

    Ariani, Cristina V; Juneja, Punita; Smith, Sophia; Tinsley, Matthew C; Jiggins, Francis M

    2015-01-01

    Mosquitoes are one of the most important vectors of human disease. The ability of mosquitoes to transmit disease is dependent on the age structure of the population, as mosquitoes must survive long enough for the parasites to complete their development and infect another human. Age could have additional effects due to mortality rates and vector competence changing as mosquitoes senesce, but these are comparatively poorly understood. We have investigated these factors using the mosquito Aedes aegypti and the filarial nematode Brugia malayi. Rather than observing any effects of immune senescence, we found that older mosquitoes were more resistant, but this only occurred if they had previously been maintained on a nutrient-poor diet of fructose. Constant blood feeding reversed this decline in vector competence, meaning that the number of parasites remained relatively unchanged as mosquitoes aged. Old females that had been maintained on fructose also experienced a sharp spike in mortality after an infected blood meal ("refeeding syndrome") and few survived long enough for the parasite to develop. Again, this effect was prevented by frequent blood meals. Our results indicate that old mosquitoes may be inefficient vectors due to low vector competence and high mortality, but that frequent blood meals can prevent these effects of age.

  10. Comparative analysis of the secretome from a model filarial nematode (Litomosoides sigmodontis) reveals maximal diversity in gravid female parasites.

    PubMed

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

    2014-10-01

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

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

    PubMed Central

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

    2014-01-01

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

  12. Small RNAs and extracellular vesicles in filarial nematodes: From nematode development to diagnostics.

    PubMed

    Quintana, J F; Babayan, S A; Buck, A H

    2017-02-01

    Parasitic nematodes have evolved sophisticated mechanisms to communicate with their hosts in order to survive and successfully establish an infection. The transfer of RNA within extracellular vesicles (EVs) has recently been described as a mechanism that could contribute to this communication in filarial nematodes. It has been shown that these EVs are loaded with several types of RNAs, including microRNAs, leading to the hypothesis that parasites could actively use these molecules to manipulate host gene expression and to the exciting prospect that these pathways could result in new diagnostic and therapeutic strategies. Here, we review the literature on the diverse RNAi pathways that operate in nematodes and more specifically our current knowledge of extracellular RNA (exRNA) and EVs derived from filarial nematodes in vitro and within their hosts. We further detail some of the issues and questions related to the capacity of RNA-mediated communication to function in parasite-host interactions and the ability of exRNA to enable us to distinguish and detect different nematode parasites in their hosts. © 2016 The Authors. Parasite Immunology published by John Wiley & Sons Ltd.

  13. Filarial and Wolbachia genomics

    PubMed Central

    SCOTT, A. L.; GHEDIN, E.; NUTMAN, T. B.; McREYNOLDS, L. A.; POOLE, C. B.; SLATKO, B. E.; FOSTER, J. M.

    2012-01-01

    SUMMARY Filarial nematode parasites, the causative agents for a spectrum of acute and chronic diseases including lymphatic filariasis and river blindness, threaten the well-being and livelihood of hundreds of millions of people in the developing regions of the world. The 2007 publication on a draft assembly of the 95-Mb genome of the human filarial parasite Brugia malayi – representing the first helminth parasite genome to be sequenced – has been followed in rapid succession by projects that have resulted in the genome sequencing of six additional filarial species, seven nonfilarial nematode parasites of animals and nearly 30 plant parasitic and free-living species. Parallel to the genomic sequencing, transcriptomic and proteomic projects have facilitated genome annotation, expanded our understanding of stage-associated gene expression and provided a first look at the role of epigenetic regulation of filarial genomes through microRNAs. The expansion in filarial genomics will also provide a significant enrichment in our knowledge of the diversity and variability in the genomes of the endosymbiotic bacterium Wolbachia leading to a better understanding of the genetic principles that govern filarial–Wolbachia mutualism. The goal here is to provide an overview of the trends and advances in filarial and Wolbachia genomics. PMID:22098559

  14. Cloning, expression and characterization of UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) from Wolbachia endosymbiont of human lymphatic filarial parasite Brugia malayi.

    PubMed

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

    2014-01-01

    Wolbachia, an endosymbiont of filarial nematode, is considered a promising target for treatment of lymphatic filariasis. Although functional characterization of the Wolbachia peptidoglycan assembly has not been fully explored, the Wolbachia genome provides evidence for coding all of the genes involved in lipid II biosynthesis, a part of peptidoglycan biosynthesis pathway. UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) is one of the lipid II biosynthesis pathway enzymes and it has inevitably been recognized as an antibiotic target. In view of the vital role of MurA in bacterial viability and survival, MurA ortholog from Wolbachia endosymbiont of Brugia malayi (wBm-MurA) was cloned, expressed and purified for further molecular characterization. The enzyme kinetics and inhibition studies were undertaken using fosfomycin. wBm-MurA was found to be expressed in all the major life stages of B. malayi and was immunolocalized in Wolbachia within the microfilariae and female adults by the confocal microscopy. Sequence analysis suggests that the amino acids crucial for enzymatic activity are conserved. The purified wBm-MurA was shown to possess the EPSP synthase (3-phosphoshikimate 1-carboxyvinyltransferase) like activity at a broad pH range with optimal activity at pH 7.5 and 37°C temperature. The apparent affinity constant (Km) for the substrate UDP-N-acetylglucosamine was found to be 0.03149 mM and for phosphoenolpyruvate 0.009198 mM. The relative enzymatic activity was inhibited ∼2 fold in presence of fosfomycin. Superimposition of the wBm-MurA homology model with the structural model of Haemophilus influenzae (Hi-MurA) suggests binding of fosfomycin at the same active site. The findings suggest wBm-MurA to be a putative antifilarial drug target for screening of novel compounds.

  15. High Pressure Freezing/Freeze Substitution Fixation Improves the Ultrastructural Assessment of Wolbachia Endosymbiont – Filarial Nematode Host Interaction

    PubMed Central

    Fischer, Kerstin; Beatty, Wandy L.; Weil, Gary J.; Fischer, Peter U.

    2014-01-01

    Background Wolbachia α-proteobacteria are essential for growth, reproduction and survival for many filarial nematode parasites of medical and veterinary importance. Endobacteria were discovered in filarial parasites by transmission electron microscopy in the 1970’s using chemically fixed specimens. Despite improvements of fixation and electron microscopy techniques during the last decades, methods to study the Wolbachia/filaria interaction on the ultrastructural level remained unchanged and the mechanisms for exchange of materials and for motility of endobacteria are not known. Methodology/Principal Finding We used high pressure freezing/freeze substitution to improve fixation of Brugia malayi and its endosymbiont, and this led to improved visualization of different morphological forms of Wolbachia. The three concentric, bilayer membranes that surround the endobacterial cytoplasm were well preserved. Vesicles with identical membrane structures were identified close to the endobacteria, and multiple bacteria were sometimes enclosed within a single outer membrane. Immunogold electron microscopy using a monoclonal antibody directed against Wolbachia surface protein-1 labeled the membranes that enclose Wolbachia and Wolbachia-associated vesicles. High densities of Wolbachia were observed in the lateral chords of L4 larvae, immature, and mature adult worms. Extracellular Wolbachia were sometimes present in the pseudocoelomic cavity near the developing female reproductive organs. Wolbachia-associated actin tails were not observed. Wolbachia motility may be explained by their residence within vacuoles, as they may co-opt the host cell’s secretory pathway to move within and between cells. Conclusions/Significance High pressure freezing/freeze substitution significantly improved the preservation of filarial tissues for electron microscopy to reveal membranes and sub cellular structures that could be crucial for exchange of materials between Wolbachia and its host. PMID

  16. Mansonella ozzardi: a neglected New World filarial nematode

    PubMed Central

    Lima, Nathália F.; Veggiani Aybar, Cecilia A.; Dantur Juri, María J.; Ferreira, Marcelo U.

    2016-01-01

    Mansonella ozzardi (Nematoda: Onchocercidae) is an understudied filarial nematode, originally described by Patrick Manson in 1897, that can be transmitted by two families of dipteran vectors, biting midges (most of them members of the genus Culicoides) and black flies (genus Simulium). With a patchy geographic distribution from southern Mexico to northwestern Argentina, human infection with M. ozzardi is highly prevalent in some of the Caribbean islands, along riverine communities in the Amazon Basin, and on both sides of the border between Bolivia and Argentina. There is no clinical entity unequivocally associated with M. ozzardi infection, although fever, arthralgia, headache, cold lower extremities, and itchy cutaneous rashes are occasionally mentioned in case report series. More recently, ocular manifestations (especially keratitis) have been associated with mansonelliasis, opening an important area of investigation. Here, we briefly review the biology, epidemiology, pathogenesis, and clinical aspects of M. ozzardi infection and point to some existing knowledge gaps, aiming to stimulate a research agenda to help filling them. PMID:27376501

  17. Effect of Certain Antibiotics Against Filarial Parasite Brugia malayi In Vitro: Possible Role of Oxidative Stress

    PubMed Central

    Mahajan, Rachna Sabharwal; Veerpathran, Anandharaman; Dakshinamoorthy, Gajalakshmi; Sharma, Richa Dwarkaprasad; Reddy, Maryada Venkatarami

    2010-01-01

    WHO-Tropical Disease Research scheme highlighted the need for development of new anti-filarial drugs. Certain antibiotics have recently been found effective against Wolbachia, co-existing symbiotically with filarial parasites. Inflammatory response entails oxidative mechanism to educe direct anti-microbial effect. In the present study microfilariae were maintained in vitro in medium supplemented with varying concentrations of tetracycline, doxycycline (20–100 μg/ml) or ciprofloxacin (50–250 μg/ml) separately to find out any involvement of oxidative mechanism in the anti-filarial effect of these antibiotics. Loss of motility of the microfilariae was measured after 48 h and correlated with the levels of MDA, nitric oxide and protein-carbonylation. Significant loss of microfilarial motility was recorded with increasing concentration of tetracycline and doxycycline but with ciprofloxacin the effect was not marked. Agents with high antifilarial activity revealed significant association with oxidative parameters in a dose dependent manner. The result suggests that oxidative effect might be exploited to design novel antifilarial drug candidate. PMID:21966105

  18. Molecular Characterization of NAD+-Dependent DNA Ligase from Wolbachia Endosymbiont of Lymphatic Filarial Parasite Brugia malayi

    PubMed Central

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

    2012-01-01

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

  19. Sequence data swell for nematodes.

    PubMed

    Hertz-Fowler, Christiane; Pain, Arnab

    2008-11-01

    With more than 80,000 described species that are extremely diverse in terms of ecology and biology, the Nematoda phylum is one of the most common animal phyla. This month's Genome Watch describes genomes of several nematodes, including that of the human filarial parasite Brugia malayi.

  20. Supergroup C Wolbachia, mutualist symbionts of filarial nematodes, have a distinct genome structure

    PubMed Central

    Comandatore, Francesco; Cordaux, Richard; Bandi, Claudio; Blaxter, Mark; Darby, Alistair; Makepeace, Benjamin L.; Montagna, Matteo; Sassera, Davide

    2015-01-01

    Wolbachia pipientis is possibly the most widespread endosymbiont of arthropods and nematodes. While all Wolbachia strains have historically been defined as a single species, 16 monophyletic clusters of diversity (called supergroups) have been described. Different supergroups have distinct host ranges and symbiotic relationships, ranging from mutualism to reproductive manipulation. In filarial nematodes, which include parasites responsible for major diseases of humans (such as Onchocerca volvulus, agent of river blindness) and companion animals (Dirofilaria immitis, the dog heartworm), Wolbachia has an obligate mutualist role and is the target of new treatment regimens. Here, we compare the genomes of eight Wolbachia strains, spanning the diversity of the major supergroups (A–F), analysing synteny, transposable element content, GC skew and gene loss or gain. We detected genomic features that differ between Wolbachia supergroups, most notably in the C and D clades from filarial nematodes. In particular, strains from supergroup C (symbionts of O. volvulus and D. immitis) present a pattern of GC skew, conserved synteny and lack of transposable elements, unique in the Wolbachia genus. These features could be the consequence of a distinct symbiotic relationship between C Wolbachia strains and their hosts, highlighting underappreciated differences between the mutualistic supergroups found within filarial nematodes. PMID:26631376

  1. Supergroup C Wolbachia, mutualist symbionts of filarial nematodes, have a distinct genome structure.

    PubMed

    Comandatore, Francesco; Cordaux, Richard; Bandi, Claudio; Blaxter, Mark; Darby, Alistair; Makepeace, Benjamin L; Montagna, Matteo; Sassera, Davide

    2015-12-01

    Wolbachia pipientis is possibly the most widespread endosymbiont of arthropods and nematodes. While all Wolbachia strains have historically been defined as a single species, 16 monophyletic clusters of diversity (called supergroups) have been described. Different supergroups have distinct host ranges and symbiotic relationships, ranging from mutualism to reproductive manipulation. In filarial nematodes, which include parasites responsible for major diseases of humans (such as Onchocerca volvulus, agent of river blindness) and companion animals (Dirofilaria immitis, the dog heartworm), Wolbachia has an obligate mutualist role and is the target of new treatment regimens. Here, we compare the genomes of eight Wolbachia strains, spanning the diversity of the major supergroups (A-F), analysing synteny, transposable element content, GC skew and gene loss or gain. We detected genomic features that differ between Wolbachia supergroups, most notably in the C and D clades from filarial nematodes. In particular, strains from supergroup C (symbionts of O. volvulus and D. immitis) present a pattern of GC skew, conserved synteny and lack of transposable elements, unique in the Wolbachia genus. These features could be the consequence of a distinct symbiotic relationship between C Wolbachia strains and their hosts, highlighting underappreciated differences between the mutualistic supergroups found within filarial nematodes. © 2015 The Authors.

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

    PubMed Central

    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

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

    PubMed Central

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

    1999-01-01

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

  4. Stage-specific and species-specific differences in the production of the mRNA and protein for the filarial nematode secreted product, ES-62.

    PubMed

    Stepek, G; Houston, K M; Goodridge, H S; Devaney, E; Harnett, W

    2004-01-01

    Previous studies have shown that the secreted phosphorylcholine-containing glycoprotein of filarial nematodes, ES-62, is only present in the post-infective life-cycle stages, but that the mRNA is transcribed throughout the worm's life-cycle. The aim of this current study was to investigate whether the presence or absence of protein expression simply reflects differences in mRNA abundance. To this end, we investigated the relative abundance of ES-62 using TaqMan real time RT-PCR, in different life-cycle stages of 2 model filarial nematode parasites, Acanthocheilonema viteae and Brugia pahangi. For B. pahangi, microfilariae, infective larvae and adult worms were each found to have approximately similar levels of ES-62 mRNA. However, the corresponding stages of A. viteae differed greatly from each other with a pattern of increased mRNA production with maturation. As a rule A. viteae had higher levels of ES-62 mRNA than B. pahangi, and this was particularly noticeable in the adult stage where the difference was approximately 3500-fold higher. However, this significant difference in mRNA abundance was not reflected in the quantity of ES-62 protein secreted by the adult worms of each species, as A. viteae only secreted approximately 3 times as much ES-62 as B. pahangi. Thus, overall, the results obtained from this study indicate that ES-62 protein production does not solely reflect mRNA levels, and also suggest that the 2 nematodes may employ different mechanisms for regulating protein production.

  5. Molecular characterization of a cyclosporin A-insensitive cyclophilin from the parasitic nematode Brugia malayi.

    PubMed

    Page, A P; Landry, D; Wilson, G G; Carlow, C K

    1995-09-12

    The cyclophilins are a family of proteins that exhibit peptidyl-prolyl cis-trans isomerase (PPIase, EC 5.2.1.8) activity and bind the immunosuppressive agent cyclosporin A (CsA) to varying degrees. We have isolated a cDNA clone encoding a novel cyclophilin from the human filarial parasite Brugia malayi. This gene possesses an N-terminal domain homologous to cyclophilins from diverse phyla (49-60% amino acid sequence identity) and a hydrophilic C-terminal domain. The cyclophilin domain was overexpressed in Escherichia coli and found to possess peptidyl-prolyl cis-trans isomerase (PPIase) activity, with a kcat/Km value of 7.9 x 10(6) M-1 s-1. A histidine residue in lieu of tryptophan in the highly conserved CsA-binding site suggests that B. malayi cyclophilin is more closely related to the cyclophilin-like proteins described recently from natural killer (NK) cells, plants, and the 40 kDa cyclophilins from mammals. In accordance with the histidine-containing CsA-binding domain, the B. malayi enzyme was relatively insensitive to inhibition by CsA, since an IC50 value of 860 nM (compared to 19 nM for human cyclophilin A) was determined.

  6. A Repurposing Strategy for Hsp90 Inhibitors Demonstrates Their Potency against Filarial Nematodes

    PubMed Central

    Gillan, Victoria; O'Neill, Kerry; Maitland, Kirsty; Sverdrup, Francis M.; Devaney, Eileen

    2014-01-01

    Novel drugs are required for the elimination of infections caused by filarial worms, as most commonly used drugs largely target the microfilariae or first stage larvae of these infections. Previous studies, conducted in vitro, have shown that inhibition of Hsp90 kills adult Brugia pahangi. As numerous small molecule inhibitors of Hsp90 have been developed for use in cancer chemotherapy, we tested the activity of several novel Hsp90 inhibitors in a fluorescence polarization assay and against microfilariae and adult worms of Brugia in vitro. The results from all three assays correlated reasonably well and one particular compound, NVP-AUY922, was shown to be particularly active, inhibiting Mf output from female worms at concentrations as low as 5.0 nanomolar after 6 days exposure to drug. NVP-AUY922 was also active on adult worms after a short 24 h exposure to drug. Based on these in vitro data, NVP-AUY922 was tested in vivo in a mouse model and was shown to significantly reduce the recovery of both adult worms and microfilariae. These studies provide proof of principle that the repurposing of currently available Hsp90 inhibitors may have potential for the development of novel agents with macrofilaricidal properties. PMID:24551261

  7. Corallopyronin A Specifically Targets and Depletes Essential Obligate Wolbachia Endobacteria From Filarial Nematodes In Vivo

    PubMed Central

    Schiefer, Andrea; Schmitz, Alexander; Schäberle, Till F.; Specht, Sabine; Lämmer, Christine; Johnston, Kelly L.; Vassylyev, Dmitry G.; König, Gabriele M.; Hoerauf, Achim; Pfarr, Kenneth

    2012-01-01

    Doxycycline and rifampicin deplete essential Wolbachia from filarial nematodes that cause lymphatic filariasis or onchocerciasis, resulting in blocked worm development and death. However, doxycycline is contraindicated for children and pregnant/breastfeeding women, as is rifampicin in the latter group with the additional specter of possible resistance development in Mycobacterium spp. Novel antibiotics with a narrower spectrum would aid in eliminating filarial diseases. Corallococcus coralloides synthesizes corallopyronin A, a noncompetitive inhibitor of RNA polymerase ineffective against Mycobacterium spp. Corallopyronin A depleted Wolbachia from infected insect cells (1.89 Thus the antibiotic is effective against intracellular bacteria despite the many intervening surfaces (blood vessels, pleura, worm cuticle) and membranes (worm cell, vesicle, Wolbachia inner and outer membranes). Corallopyronin A is an antibiotic to develop further for filariasis elimination without concern for cross-resistance development in tuberculosis. PMID:22586066

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

    PubMed Central

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

    2014-01-01

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

  9. Xenomonitoring of Different Filarial Nematodes Using Single and Multiplex PCR in Mosquitoes from Assiut Governorate, Egypt

    PubMed Central

    Dyab, Ahmed Kamal; Galal, Lamia Ahmed; Mahmoud, Abeer El-Sayed; Mokhtar, Yasser

    2015-01-01

    Wuchereria bancrofti, Dirofilaria immitis, and Dirofilaria repens are filarial nematodes transmitted by mosquitoes belonging to Culex, Aedes, and Anopheles genera. Screening by vector dissection is a tiresome technique. We aimed to screen filarial parasites in their vectors by single and multiplex PCR and evaluate the usefulness of multiplex PCR as a rapid xenomonitoring and simultaneous differentiation tool, in area where 3 filarial parasites are coexisting. Female mosquitoes were collected from 7 localities in Assiut Governorate, were microscopically identified and divided into pools according to their species and collection site. Detection of W. bancrofti, D. immitis, and D. repens using single PCR was reached followed by multiplex PCR. Usefulness of multiplex PCR was evaluated by testing mosquito pools to know which genera and species are used by filarial parasites as a vector. An overall estimated rate of infection (ERI) in mosquitoes was 0.6%; the highest was Culex spp. (0.47%). W. bancrofti, D. immitis, and D. repens could be simultaneously and differentially detected in infected vectors by using multiplex PCR. Out of 100 mosquito pools, 8 were positive for W. bancrofti (ERI of 0.33%) and 3 pools each were positive for D. immitis and D. repens (ERI 0.12%). The technique showed 100% sensitivity and 98% specificity. El-Nikhila, El-Matiaa villages, and Sahel Seleem district in Assiut Governorate, Egypt are still endemic foci for filarial parasites. Multiplex PCR offers a reliable procedure for molecular xenomonitoring of filariasis within their respective vectors in endemic areas. Therefore, it is recommended for evaluation of mosquito infection after lymphatic filariasis eradication programs. PMID:25748712

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

    PubMed Central

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

    2016-01-01

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

  11. Distribution and molecular characterization of Wolbachia endosymbionts and filarial nematodes in Maryland populations of the lone star tick (Amblyomma americanum).

    PubMed

    Zhang, Xing; Norris, Douglas E; Rasgon, Jason L

    2011-07-01

    The lone star tick Amblyomma americanum is host to a wide diversity of endosymbiotic bacteria. We identified a novel Wolbachia symbiont infecting A. americanum. Multilocus sequence typing phylogenetically placed the endosymbiont in the increasingly diverse F supergroup. We assayed a total of 1031 ticks (119 females, 78 males and 834 nymphs in 89 pools) from 16 Maryland populations for infection. Infection frequencies in the natural populations were approximately 5% in females and <2% (minimum infection rate) in nymphs; infection was not detected in males. Infected populations were only observed in southern Maryland, suggesting the possibility that Wolbachia is currently invading Maryland A. americanum populations. Because F supergroup Wolbachia have been detected previously in filarial nematodes, tick samples were assayed for nematodes by PCR. Filarial nematodes were detected in 70% and 9% of Wolbachia-positive and Wolbachia-negative tick samples, respectively. While nematodes were more common in Wolbachia-positive tick samples, the lack of a strict infection concordance (Wolbachia-positive, nematode-negative and Wolbachia-negative, nematode-positive ticks) suggests that Wolbachia prevalence in ticks is not due to nematode infection. Supporting this hypothesis, phylogenetic analysis indicated that the nematodes were likely a novel species within the genus Acanthocheilonema, which has been previously shown to be Wolbachia-free. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  12. Humans from Wuchereria bancrofti endemic area elicit substantial immune response to proteins of the filarial parasite Brugia malayi and its endosymbiont Wolbachia.

    PubMed

    Jha, Ruchi; Gangwar, Mamta; Chahar, Dhanvantri; Setty Balakrishnan, Anand; Negi, Mahendra Pal Singh; Misra-Bhattacharya, Shailja

    2017-01-24

    In the past, immune responses to several Brugia malayi immunodominant antigens have been characterized in filaria-infected populations; however, little is known regarding Wolbachia proteins. We earlier cloned and characterized few B. malayi (trehalose-6-phosphate phosphatase, Bm-TPP and heavy chain myosin, BmAF-Myo) and Wolbachia (translation initiation factor-1, Wol Tl IF-1 and NAD(+)-dependent DNA ligase, wBm-LigA) proteins and investigated the immune responses, which they triggered in animal models. The current study emphasizes on immunological characteristics of these proteins in three major categories of filarial endemic zones: endemic normal (EN, asymptomatic, amicrofilaraemic; putatively immune), microfilariae carriers (MF, asymptomatic but microfilaraemic), and chronic filarial patients (CP, symptomatic and mostly amicrofilaraemic). Immunoblotting and ELISA were carried out to measure IgG and isotype antibodies against these recombinant proteins in various clinical categories. Involvement of serum antibodies in infective larvae killing was assessed by antibody-dependent cellular adhesion and cytotoxicity assay. Cellular immune response was investigated by in vitro proliferation of peripheral blood mononuclear cells (PBMCs) and reactive oxygen species (ROS) generation in these cells after stimulation. Immune responses of EN and CP displayed almost similar level of IgG to Wol Tl IF-1 while other three proteins had higher serum IgG in EN individuals only. Specific IgA, IgG1, IgG3 and IgM to Bm-TPP were high in EN subjects, while BmAF-Myo additionally showed elevated IgG2. Enhanced IgA and IgG3 were detected in both EN and CP individuals in response to Wol Tl IF-1 antigen, but IgG1 and IgM were high only in EN individuals. wBm-LigA and BmAF-Myo exhibited almost similar pattern of antibody responses. PBMC isolated from EN subjects exhibited higher proliferation and ROS generation when stimulated with all three proteins except for Wol Tl IF-1. Overall, these

  13. Investigation of strategies with potential for producing a phosphorylcholine-free version of the filarial nematode immunomodulator, ES-62.

    PubMed

    Houston, K M; Egan, C A; García, P; Harnett, W

    2006-09-01

    Phosphorylcholine (PC) is found attached to N-type glycans of proteins secreted by filarial nematodes, where it appears to act as an immunomodulator. Based on information on the structure and biosynthesis of the PC-glycan of a major secreted protein, ES-62, strategies were designed with potential for preparing PC-free material to better understand the importance of PC in filarial nematode immunomodulation. The strategies involve either enzymatic removal of PC or inhibition of its attachment during ES-62 synthesis. No method tested was found to be 100% effective although approximately 70% removal was obtained by culturing worms in Et18OCH3. Reasons for failure to obtain complete absence of PC moieties are discussed in relation to the structure and synthesis of PC-glycans and in addition PC-glycan biosynthesis is briefly commented on as a target for chemotherapy.

  14. Diversity in parasitic nematode genomes: the microRNAs of Brugia pahangi and Haemonchus contortus are largely novel

    PubMed Central

    2012-01-01

    Background MicroRNAs (miRNAs) play key roles in regulating post-transcriptional gene expression and are essential for development in the free-living nematode Caenorhabditis elegans and in higher organisms. Whether microRNAs are involved in regulating developmental programs of parasitic nematodes is currently unknown. Here we describe the the miRNA repertoire of two important parasitic nematodes as an essential first step in addressing this question. Results The small RNAs from larval and adult stages of two parasitic species, Brugia pahangi and Haemonchus contortus, were identified using deep-sequencing and bioinformatic approaches. Comparative analysis to known miRNA sequences reveals that the majority of these miRNAs are novel. Some novel miRNAs are abundantly expressed and display developmental regulation, suggesting important functional roles. Despite the lack of conservation in the miRNA repertoire, genomic positioning of certain miRNAs within or close to specific coding genes is remarkably conserved across diverse species, indicating selection for these associations. Endogenous small-interfering RNAs and Piwi-interacting (pi)RNAs, which regulate gene and transposon expression, were also identified. piRNAs are expressed in adult stage H. contortus, supporting a conserved role in germline maintenance in some parasitic nematodes. Conclusions This in-depth comparative analysis of nematode miRNAs reveals the high level of divergence across species and identifies novel sequences potentially involved in development. Expression of novel miRNAs may reflect adaptations to different environments and lifestyles. Our findings provide a detailed foundation for further study of the evolution and function of miRNAs within nematodes and for identifying potential targets for intervention. PMID:22216965

  15. Thioredoxin peroxidases from Brugia malayi.

    PubMed

    Ghosh, I; Eisinger, S W; Raghavan, N; Scott, A L

    1998-03-15

    Parasite-derived antioxidant proteins have been implicated in playing an important role in protection against the oxygen radicals that are generated during aerobic metabolism and in defense against host immune cell attack. Here we report that filarial nematodes include the thioredoxin peroxidase/thiol-specific antioxidant (TPx/TSA) family of antioxidant proteins as part of their complex defense against radical-mediated damage. At the protein level, the TPx/TSA from Brugia malayi (Bm-TPx-1) was approximately 50% identical and approximately 60% similar to TPx/TSAs from mammals, amphibians and yeast. Bm-TPx-1 was also approximately 60% identical to putative TPx proteins from a related filarial nematode, Onchocerca volvulus, and from the free-living nematode Caenorhabditis elegans. That B. malayi may express multiple forms of molecules with TPx/TSA activity was indicated by the identification of a B. malayi gene encoding a second, distinct member of the TPx/TSA family (Bm-tpx-2). Bm-tpx-1 was found to be transcribed in all stages of the parasite present in the mammalian host and the 25 kDa translation product was present in all of the developmental stages studied. The results of immunohistochemical, immunofluorescent and immunoprecipitation studies showed Bm-TPx-1 to be localized in the cells of the hypodermis/lateral chord in adult parasites and not to be present at the surface or in excretory/secretory products. The distribution in the parasite suggests that Bm-TPx-1 may play its major role in countering radicals produced within cells. A recombinant form of Bm-TPx-1 was biologically active and capable of protecting DNA from oxygen radical-mediated damage. Thioredoxin peroxidases may prove to be a critical component in the parasite's defense against injury caused by oxygen radicals derived from endogenous and exogenous sources.

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

    PubMed

    Lefoulon, Emilie; Bain, Odile; 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

    2015-11-01

    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.

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

    PubMed Central

    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

  18. The therapeutic potential of the filarial nematode-derived immunodulator, ES-62 in inflammatory disease.

    PubMed

    Harnett, M M; Melendez, A J; Harnett, W

    2010-03-01

    The dramatic recent rise in the incidence of allergic or autoimmune inflammatory diseases in the West has been proposed to reflect the lack of appropriate priming of the immune response by infectious agents such as parasitic worms during childhood. Consistent with this, there is increasing evidence supporting an inverse relationship between worm infection and T helper type 1/17 (Th1/17)-based inflammatory disorders such as rheumatoid arthritis, inflammatory bowel disease, type 1 diabetes and multiple sclerosis. Perhaps more surprisingly, given that such worms often induce strong Th2-type immune responses, there also appears to be an inverse correlation between parasite load and atopy. These findings therefore suggest that the co-evolution of helminths with hosts, which has resulted in the ability of worms to modulate inflammatory responses to promote parasite survival, has also produced the benefit of protecting the host from pathological lesions arising from aggressive proinflammatory responses to infection or, indeed, aberrant inflammatory responses underlying autoimmune and allergic disorders. By focusing upon the properties of the filarial nematode-derived immunomodulatory molecule, ES-62, in this review we shall discuss the potential of exploiting the immunomodulatory products of parasitic worms to identify and develop novel therapeutics for inflammation.

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

    PubMed Central

    Villemaine, Estelle; Poole, Catherine B.; Chapman, Melissa S.; Pollastri, Michael P.; Wyatt, Paul G.; Carlow, Clotilde K. S.

    2014-01-01

    Myristoylation is a lipid modification involving the addition of a 14-carbon unsaturated fatty acid, myristic acid, to the N-terminal glycine of a subset of proteins, a modification that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in human cancers, and for infectious diseases caused by fungi, viruses and protozoan parasites. We purified Caenorhabditis elegans and Brugia malayi NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and peptide substrates. Biochemical and structural analyses both revealed that the nematode enzymes are canonical NMTs, sharing a high degree of conservation with protozoan NMT enzymes. Inhibitory compounds that target NMT in protozoan species inhibited the nematode NMTs with IC50 values of 2.5–10 nM, and were active against B. malayi microfilariae and adult worms at 12.5 µM and 50 µM respectively, and C. elegans (25 µM) in culture. RNA interference and gene deletion in C. elegans further showed that NMT is essential for nematode viability. The effects observed are likely due to disruption of the function of several downstream target proteins. Potential substrates of NMT in B. malayi are predicted using bioinformatic analysis. Our genetic and chemical studies highlight the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against nematode diseases including filariasis. PMID:25188325

  20. Prevalence and pathogenesis of some filarial nematodes infecting donkeys in Egypt

    PubMed Central

    Radwan, A. M.; Ahmed, N. E.; Elakabawy, L. M.; Ramadan, M. Y.; Elmadawy, R. S.

    2016-01-01

    Aim: The primary objective of the present study is to determine the commonness of filarial parasites in donkeys in Egypt, identification of the filarial species tainting them and the delivered pathogenic impact connected with the infestation. Materials and Methods: A total of 188 donkeys were examined for filarial infection. The blood samples and scraping of the cutaneous bleeding lesions were collected, stained, and inspected for microfilariae all through the period from March 2011 to October 2013. The adult worms were perceived in tissue samples acquired from skin scraping, testes, eyes, tendons, peritoneal and pleural cavities, and the ligamentum nuchae. Results: On the basis of morphological identification, 163 of 188 donkeys (86.70%) were infected with Onchocerca cervicalis (82.98%), Setaria equina (31.11%), Parafilaria multipapillosa (5.32%), and Onchocerca reticulata (4.26%). There was no significant effect of the sex on the incidence of all the encounteredfilarial worms except for S. equina, where the infection rate prevailed in males versus females (40.82% vs. 35.90%). In addition, age group of 5-15 years old exhibited a fundamentally higher predominance (p< 0.05) of the recognized filarial worms versus those of < 5 years old and >15 years old. Conclusion: The preliminary results add to our comprehension of filarial species infecting donkeys in Egypt, their impact on animal execution and production. Accentuation must be taken for avoidance, control of filarial disease, and improvement of the management system of donkeys. PMID:27651679

  1. Depression of endothelium-dependent relaxation in aorta from rats with Brugia pahangi lymphatic filariasis.

    PubMed

    Kaiser, L; Tithof, P K; Lamb, V L; Williams, J F

    1991-06-01

    A role for altered endothelial cell function is emerging in the pathogenesis of disease. We have previously demonstrated that Dirofilaria immitis, the canine heartworm, depresses endothelium-dependent responses and alters the mechanism of relaxation in the in vivo femoral artery of infected dogs. Exposure of rat aorta to the parasite or parasite-conditioned medium selectively depresses endothelium-dependent relaxation. D. immitis is closely related to the major human filarial pathogens. This study was designed to examine the effect of chronic infection with the filarial nematode Brugia pahangi on endothelium-mediated responses of the rat aorta in vitro. We tested the hypothesis that endothelium-dependent responses are depressed in the aorta from rats infected with B. pahangi. Rings of thoracic and abdominal aorta were suspended in muscle baths for measurement of isometric tension. Dose-response relations to norepinephrine, endothelium-dependent dilators (acetylcholine, histamine, and A23187), and nitroglycerin were done. In some experiments, inhibitors of cyclooxygenase (indomethacin and aspirin), guanylate cyclase (methylene blue), and nitric oxide formation (N-nitro-L-arginine methyl ester; L-NOARG) were used. No differences in vascular reactivity were detected in the thoracic aorta. In contrast, endothelium-dependent responses in abdominal aorta of Brugia-infected rats were significantly depressed when compared with control aorta from noninfected rats. Acetylcholine relaxation was further depressed by indomethacin and aspirin. After L-NOARG, acetylcholine relaxation in control abdominal aorta was completely abolished; however, in abdominal aorta of Brugia-infected rats, acetylcholine still caused relaxation. Methylene blue inhibited acetylcholine relaxation in both control and Brugia-infected abdominal aorta; however, relaxation in Brugia-infected aorta was significantly greater than control. This study demonstrates that endothelium-dependent relaxation can be

  2. Prolyl 4-Hydroxlase Activity Is Essential for Development and Cuticle Formation in the Human Infective Parasitic Nematode Brugia malayi*

    PubMed Central

    Winter, Alan D.; McCormack, Gillian; Myllyharju, Johanna; Page, Antony P.

    2013-01-01

    Collagen prolyl 4-hydroxylases (C-P4H) are required for formation of extracellular matrices in higher eukaryotes. These enzymes convert proline residues within the repeat regions of collagen polypeptides to 4-hydroxyproline, a modification essential for the stability of the final triple helix. C-P4H are most often oligomeric complexes, with enzymatic activity contributed by the α subunits, and the β subunits formed by protein disulfide isomerase (PDI). Here, we characterize this enzyme class in the important human parasitic nematode Brugia malayi. All potential C-P4H subunits were identified by detailed bioinformatic analysis of sequence databases, function was investigated both by RNAi in the parasite and heterologous expression in Caenorhabditis elegans, whereas biochemical activity and complex formation were examined via co-expression in insect cells. Simultaneous RNAi of two B. malayi C-P4H α subunit-like genes resulted in a striking, highly penetrant body morphology phenotype in parasite larvae. This was replicated by single RNAi of a B. malayi C-P4H β subunit-like PDI. Surprisingly, however, the B. malayi proteins were not capable of rescuing a C. elegans α subunit mutant, whereas the human enzymes could. In contrast, the B. malayi PDI did functionally complement the lethal phenotype of a C. elegans β subunit mutant. Comparison of recombinant and parasite derived material indicates that enzymatic activity may be dependent on a non-reducible covalent link, present only in the parasite. We therefore demonstrate that C-P4H activity is essential for development of B. malayi and uncover a novel parasite-specific feature of these collagen biosynthetic enzymes that may be exploited in future parasite control. PMID:23223450

  3. Defining Brugia malayi and Wolbachia symbiosis by stage-specific dual RNA-seq.

    PubMed

    Grote, Alexandra; Voronin, Denis; Ding, Tao; Twaddle, Alan; Unnasch, Thomas R; Lustigman, Sara; Ghedin, Elodie

    2017-03-01

    Filarial nematodes currently infect up to 54 million people worldwide, with millions more at risk for infection, representing the leading cause of disability in the developing world. Brugia malayi is one of the causative agents of lymphatic filariasis and remains the only human filarial parasite that can be maintained in small laboratory animals. Many filarial nematode species, including B. malayi, carry an obligate endosymbiont, the alpha-proteobacteria Wolbachia, which can be eliminated through antibiotic treatment. Elimination of the endosymbiont interferes with development, reproduction, and survival of the worms within the mamalian host, a clear indicator that the Wolbachia are crucial for survival of the parasite. Little is understood about the mechanism underlying this symbiosis. To better understand the molecular interplay between these two organisms we profiled the transcriptomes of B. malayi and Wolbachia by dual RNA-seq across the life cycle of the parasite. This helped identify functional pathways involved in this essential symbiotic relationship provided by the co-expression of nematode and bacterial genes. We have identified significant stage-specific and gender-specific differential expression in Wolbachia during the nematode's development. For example, during female worm development we find that Wolbachia upregulate genes involved in ATP production and purine biosynthesis, as well as genes involved in the oxidative stress response. This global transcriptional analysis has highlighted specific pathways to which both Wolbachia and B. malayi contribute concurrently over the life cycle of the parasite, paving the way for the development of novel intervention strategies.

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

    PubMed

    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.

  5. Detection and differentiation of filarial parasites by universal primers and polymerase chain reaction-restriction fragment length polymorphism analysis.

    PubMed

    Nuchprayoon, Surang; Junpee, Alisa; Poovorawan, Yong; Scott, Alan L

    2005-11-01

    Filarial nematode parasites are a serious cause of morbidity in humans and animals. Identification of filarial infection using traditional morphologic criteria can be difficult and lead to misdiagnosis. We report on a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based method to detect and differentiate a broad range of filarial species in a single PCR. The first internal transcribed spacer 1 (ITS1) along with the flanking 18S and 5.8S ribosomal DNA (rDNA) were isolated and cloned from Wuchereria bancrofti, Brugia malayi, and Brugia pahangi. Sequence analysis identified conserved sites in the 18S and 5.8S rDNA sequence that could be used as universal priming sites to generate ITS1-distinctive PCR products that were useful for distinguishing filariae at the genus level. The addition of a digestion of the ITS1 PCR product with the restriction endonuclease Ase I generated a fragment profile that allowed differentiation down to the species level for W. bancrofti, B. malayi, B. pahangi, Dirofilaria immitis, and D. repens. The PCR-RFLP of ITS1 rDNA will be useful in diagnosing and differentiating filarial parasites in human, animal reservoir hosts, and mosquito vectors in disease-endemic areas.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  8. Modulation of human T cell responses and macrophage functions by onchocystatin, a secreted protein of the filarial nematode Onchocerca volvulus.

    PubMed

    Schönemeyer, A; Lucius, R; Sonnenburg, B; Brattig, N; Sabat, R; Schilling, K; Bradley, J; Hartmann, S

    2001-09-15

    Immune responses of individuals infected with filarial nematodes are characterized by a marked cellular hyporesponsiveness and a shift of the cytokine balance toward a Th2/Th3 response. This modulation of cellular immune responses is considered as an important mechanism to avoid inflammatory immune responses that could eliminate the parasites. We investigated the immunomodulatory potential of a secreted cysteine protease inhibitor (onchocystatin) of the human pathogenic filaria Onchocerca volvulus. Recombinant onchocystatin (rOv17), a biologically active cysteine protease inhibitor that inhibited among others the human cysteine proteases cathepsins L and S, suppressed the polyclonally stimulated and the Ag-driven proliferation of human PBMC. Stimulated as well as unstimulated PBMC in the presence of rOv17 produced significantly more IL-10, which was paralleled in some situations by a decrease of IL-12p40 and preceded by an increase of TNF-alpha. At the same time, rOv17 reduced the expression of HLA-DR proteins and of the costimulatory molecule CD86 on human monocytes. Neutralization of IL-10 by specific Abs restored the expression of HLA-DR and CD86, whereas the proliferative block remained unaffected. Depletion of monocytes from the PBMC reversed the rOv17-induced cellular hyporeactivity, indicating monocytes to be the target cells of immunomodulation. Therefore, onchocystatin has the potential to contribute to a state of cellular hyporesponsiveness and is a possible pathogenicity factor essential for the persistence of O. volvulus within its human host.

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

    PubMed

    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.

  10. Tetracycline treatment targeting Wolbachia affects expression of an array of proteins in Brugia malayi parasite.

    PubMed

    Dangi, Anil; Vedi, Satish; Nag, Jeetendra Kumar; Paithankar, Sameer; Singh, Mahendra Pratap; Kar, Santosh Kumar; Dube, Anuradha; Misra-Bhattacharya, Shailja

    2009-09-01

    Wolbachia is an intracellular endosymbiont of Brugia malayi parasite whose presence is essential for the survival of the parasite. Treatment of B. malayi-infected jirds with tetracycline eliminates Wolbachia, which affects parasite survival and fitness. In the present study we have tried to identify parasite proteins that are affected when Wolbachia is targeted by tetracycline. For this Wolbachia depleted parasites (B. malayi) were obtained by tetracycline treatment of infected Mongolian jirds (Meriones unguiculatus) and their protein profile after 2-DE separation was compared with that of untreated parasites harboring Wolbachia. Approximately 100 protein spots could be visualized followed by CBB staining of 2-D gel and included for comparative analysis. Of these, 54 showed differential expressions, while two new protein spots emerged (of 90.3 and 64.4 kDa). These proteins were subjected to further analysis by MALDI-TOF for their identification using Brugia coding sequence database composed of both genomic and EST sequences. Our study unravels two crucial findings: (i) the parasite or Wolbachia proteins, which disappeared/down-regulated appear be essential for parasite survival and may be used as drug targets and (ii) tetracycline treatment interferes with the regulatory machinery vital for parasites cellular integrity and defense and thus could possibly be a molecular mechanism for the killing of filarial parasite. This is the first proteomic study substantiating the wolbachial genome integrity with its nematode host and providing functional genomic data of human lymphatic filarial parasite B. malayi.

  11. Assay Strategies for the Discovery and Validation of Therapeutics Targeting Brugia pahangi Hsp90

    PubMed Central

    Taldone, Tony; Gillan, Victoria; Sun, Weilin; Rodina, Anna; Patel, Pallav; Maitland, Kirsty; O'Neill, Kerry; Chiosis, Gabriela; Devaney, Eileen

    2010-01-01

    The chemotherapy of lymphatic filariasis relies upon drugs such as diethylcarbamazine and ivermectin that largely target the microfilarial stages of the parasite, necessitating continued treatment over the long reproductive life span of the adult worm. The identification of compounds that target adult worms has been a long-term goal of WHO. Here we describe a fluorescence polarization assay for the identification of compounds that target Hsp90 in adult filarial worms. The assay was originally developed to identify inhibitors of Hsp90 in tumor cells, and relies upon the ability of small molecules to inhibit the binding of fluorescently labelled geldanamycin to Hsp90. We demonstrate that the assay works well with soluble extracts of Brugia, while extracts of the free-living nematode C. elegans fail to bind the probe, in agreement with data from other experiments. The assay was validated using known inhibitors of Hsp90 that compete with geldanamycin for binding to Hsp90, including members of the synthetic purine-scaffold series of compounds. The efficacy of some of these compounds against adult worms was confirmed in vitro. Moreover, the assay is sufficiently sensitive to differentiate between binding of purine-scaffold compounds to human and Brugia Hsp90. The assay is suitable for high-throughput screening and provides the first example of a format with the potential to identify novel inhibitors of Hsp90 in filarial worms and in other parasitic species where Hsp90 may be a target. PMID:20559560

  12. New Insights into the Evolution of Wolbachia Infections in Filarial Nematodes Inferred from a Large Range of Screened Species

    PubMed Central

    Barbuto, Michela; Martin, Coralie; Lo, Nathan; Uni, Shigehiko; Landmann, Frederic; Baccei, Sara G.; Guerrero, Ricardo; de Souza Lima, Sueli; Bandi, Claudio; Wanji, Samuel; Diagne, Moustapha; Casiraghi, Maurizio

    2011-01-01

    Background 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. Methodology/Principal Findings 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. Conclusions/Significance 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

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

    PubMed

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

    2016-04-01

    Wuchereria bancrofti is a parasitic nematode and the primary cause of lymphatic filariasis--a disease specific to humans. W. bancrofti currently infects over 90 million people throughout the tropics and has been acknowledged by the world health organization as a vulnerable parasite. Current research has focused primarily on the clinical manifestations of disease and little is known about the evolutionary history of W. bancrofti. To improve upon knowledge of the evolutionary history of W. bancrofti, we whole genome sequenced 13 W. bancrofti larvae. We circumvent many of the difficulties of multiple infections by sampling larvae directly from mosquitoes that were experimentally inoculated with infected blood. To begin, we used whole genome data to reconstruct the historical population size. Our results support a history of fluctuating population sizes that can be correlated with human migration and fluctuating mosquito abundances. Next, we reconstructed the putative pedigree of W. bancrofti worms within an infection using the kinship coefficient. We deduced that there are full-sib and half-sib relationships residing within the same larval cohort. Through combined analysis of the mitochondrial and nuclear genomes we concluded that this is likely a results of polyandrous mating, the first time reported for W. bancrofti. Lastly, we scanned the genomes for signatures of natural selection. Annotation of putative selected regions identified proteins that may have aided in a parasitic life style or may have evolved to protect against current drug treatments. We discuss our results in the greater context of understanding the biology of an animal with a unique life history and ecology. © 2016 John Wiley & Sons Ltd.

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

    PubMed Central

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

    2008-01-01

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

  15. Defining Brugia malayi and Wolbachia symbiosis by stage-specific dual RNA-seq

    PubMed Central

    Voronin, Denis; Ding, Tao; Twaddle, Alan; Unnasch, Thomas R.; Lustigman, Sara; Ghedin, Elodie

    2017-01-01

    Background Filarial nematodes currently infect up to 54 million people worldwide, with millions more at risk for infection, representing the leading cause of disability in the developing world. Brugia malayi is one of the causative agents of lymphatic filariasis and remains the only human filarial parasite that can be maintained in small laboratory animals. Many filarial nematode species, including B. malayi, carry an obligate endosymbiont, the alpha-proteobacteria Wolbachia, which can be eliminated through antibiotic treatment. Elimination of the endosymbiont interferes with development, reproduction, and survival of the worms within the mamalian host, a clear indicator that the Wolbachia are crucial for survival of the parasite. Little is understood about the mechanism underlying this symbiosis. Methodology/ Principle findings To better understand the molecular interplay between these two organisms we profiled the transcriptomes of B. malayi and Wolbachia by dual RNA-seq across the life cycle of the parasite. This helped identify functional pathways involved in this essential symbiotic relationship provided by the co-expression of nematode and bacterial genes. We have identified significant stage-specific and gender-specific differential expression in Wolbachia during the nematode’s development. For example, during female worm development we find that Wolbachia upregulate genes involved in ATP production and purine biosynthesis, as well as genes involved in the oxidative stress response. Conclusions/ Significance This global transcriptional analysis has highlighted specific pathways to which both Wolbachia and B. malayi contribute concurrently over the life cycle of the parasite, paving the way for the development of novel intervention strategies. PMID:28358880

  16. Molecular Evidence for a Functional Ecdysone Signaling System in Brugia malayi

    PubMed Central

    Tzertzinis, George; Egaña, Ana L.; Palli, Subba Reddy; Robinson-Rechavi, Marc; Gissendanner, Chris R.; Liu, Canhui; Unnasch, Thomas R.; Maina, Claude V.

    2010-01-01

    Background Filarial nematodes, including Brugia malayi, the causative agent of lymphatic filariasis, undergo molting in both arthropod and mammalian hosts to complete their life cycles. An understanding of how these parasites cross developmental checkpoints may reveal potential targets for intervention. Pharmacological evidence suggests that ecdysteroids play a role in parasitic nematode molting and fertility although their specific function remains unknown. In insects, ecdysone triggers molting through the activation of the ecdysone receptor: a heterodimer of EcR (ecdysone receptor) and USP (Ultraspiracle). Methods and Findings We report the cloning and characterization of a B. malayi EcR homologue (Bma-EcR). Bma-EcR dimerizes with insect and nematode USP/RXRs and binds to DNA encoding a canonical ecdysone response element (EcRE). In support of the existence of an active ecdysone receptor in Brugia we also cloned a Brugia rxr (retinoid X receptor) homolog (Bma-RXR) and demonstrate that Bma-EcR and Bma-RXR interact to form an active heterodimer using a mammalian two-hybrid activation assay. The Bma-EcR ligand-binding domain (LBD) exhibits ligand-dependent transactivation via a GAL4 fusion protein combined with a chimeric RXR in mammalian cells treated with Ponasterone-A or a synthetic ecdysone agonist. Furthermore, we demonstrate specific up-regulation of reporter gene activity in transgenic B. malayi embryos transfected with a luciferase construct controlled by an EcRE engineered in a B. malayi promoter, in the presence of 20-hydroxy-ecdysone. Conclusions Our study identifies and characterizes the two components (Bma-EcR and Bma-RXR) necessary for constituting a functional ecdysteroid receptor in B. malayi. Importantly, the ligand binding domain of BmaEcR is shown to be capable of responding to ecdysteroid ligands, and conversely, ecdysteroids can activate transcription of genes downstream of an EcRE in live B. malayi embryos. These results together confirm that

  17. Transcriptomes and pathways associated with infectivity, survival and immunogenicity in Brugia malayi L3

    PubMed Central

    Li, Ben-Wen; Rush, Amy C; Mitreva, Makedonka; Yin, Yong; Spiro, David; Ghedin, Elodie; Weil, Gary J

    2009-01-01

    Background Filarial nematode parasites cause serious diseases such as elephantiasis and river blindness in humans, and heartworm infections in dogs. Third stage filarial larvae (L3) are a critical stage in the life cycle of filarial parasites, because this is the stage that is transmitted by arthropod vectors to initiate infections in mammals. Improved understanding of molecular mechanisms associated with this transition may provide important leads for development of new therapies and vaccines to prevent filarial infections. This study explores changes in gene expression associated with the transition of Brugia malayi third stage larvae (BmL3) from mosquitoes into mammalian hosts and how these changes are affected by radiation. Radiation effects are especially interesting because irradiated L3 induce partial immunity to filarial infections. The underlying molecular mechanisms responsible for the efficacy of such vaccines are unkown. Results Expression profiles were obtained using a new filarial microarray with 18, 104 64-mer elements. 771 genes were identified as differentially expressed in two-way comparative analyses of the three L3 types. 353 genes were up-regulated in mosquito L3 (L3i) relative to cultured L3 (L3c). These genes are important for establishment of filarial infections in mammalian hosts. Other genes were up-regulated in L3c relative to L3i (234) or irradiated L3 (L3ir) (22). These culture-induced transcripts include key molecules required for growth and development. 165 genes were up-regulated in L3ir relative to L3c; these genes encode highly immunogenic proteins and proteins involved in radiation repair. L3ir and L3i have similar transcription profiles for genes that encode highly immunogenic proteins, antioxidants and cuticle components. Conclusion Changes in gene expression that normally occur during culture under conditions that support L3 development and molting are prevented or delayed by radiation. This may explain the enhanced

  18. Tissue migration capability of larval and adult Brugia pahangi.

    PubMed

    Chirgwin, Sharon R; Coleman, Sharon U; Porthouse, Kristina H; Klei, Thomas R

    2006-02-01

    Infection with mosquito-born filarial nematodes occurs when hosts are bitten by a vector carrying the infective third stage larvae (L3) of the parasites. These larvae, deposited on the skin by the feeding mosquito, are presumed to enter the skin via the vector-induced puncture wound. Larvae of Brugia spp. must then migrate from the entry site, penetrate various skin layers, and locate a lymphatic vessel that leads to their lymphatic predilection site. We have recently established an intradermal (ID) infection model using B. pahangi and the Mongolian gerbil, allowing us to investigate the migratory capability ofB. pahangi. Larval and adult parasites recovered from the peritoneal cavities of gerbils were capable of establishing an infection following ID (larvae) or subcutaneous (adult) injection. Third and fourth stage larvae both migrated away from the injection site within hours, although data suggest they localize to different lymphatic tissues at 3 days postinfection (DPI). Immature adult (28 day) B. pahangi also migrated away from their SC inoculation site within 7 DPI. Mature (45 day) adult B. pahangi displayed little migration away from the SC infection site, suggesting tissue migration may be limited to developing stages of the parasite.

  19. The Effect of In Vitro Cultivation on the Transcriptome of Adult Brugia malayi

    PubMed Central

    O’Neill, Maeghan; Burkman, Erica; Zaky, Weam I.; Xia, Jianguo; Moorhead, Andrew; Williams, Steven A.; Geary, Timothy G.

    2016-01-01

    Background Filarial nematodes cause serious and debilitating infections in human populations of tropical countries, contributing to an entrenched cycle of poverty. Only one human filarial parasite, Brugia malayi, can be maintained in rodents in the laboratory setting. It has been a widely used model organism in experiments that employ culture systems, the impact of which on the worms is unknown. Methodology/Principal Findings Using Illumina RNA sequencing, we characterized changes in gene expression upon in vitro maintenance of adult B. malayi female worms at four time points: immediately upon removal from the host, immediately after receipt following shipment, and after 48 h and 5 days in liquid culture media. The dramatic environmental change and the 24 h time lapse between removal from the host and establishment in culture caused a globally dysregulated gene expression profile. We found a maximum of 562 differentially expressed genes based on pairwise comparison between time points. After an initial shock upon removal from the host and shipping, a few stress fingerprints remained after 48 h in culture and until the experiment was stopped. This was best illustrated by a strong and persistent up-regulation of several genes encoding cuticle collagens, as well as serpins. Conclusions/Significance These findings suggest that B. malayi can be maintained in culture as a valid system for pharmacological and biological studies, at least for several days after removal from the host and adaptation to the new environment. However, genes encoding several stress indicators remained dysregulated until the experiment was stopped. PMID:26727204

  20. Oxidative stress plays major role in mediating apoptosis in filarial nematode Setaria cervi in the presence of trans-stilbene derivatives.

    PubMed

    Mukherjee, Niladri; Parida, Pravat Kumar; Santra, Abhishek; Ghosh, Tamashree; Dutta, Ananya; Jana, Kuladip; Misra, Anup Kumar; Sinha Babu, Santi P

    2016-04-01

    Lymphatic filariasis, affecting around 120 million people in 80 countries worldwide, is an extremely painful disease and caused permanent and long term disability. Owing to its alarming prevalence there is immediate need for development of new therapeutics. A series of trans-stilbene derivatives were synthesized using aqueous reaction condition showing potential as antifilarial agents demonstrated in vitro. MTT reduction assay and dye exclusion test were performed to evaluate the micro and macrofilaricidal potential of these compounds. Amid 20 trans-stilbene derivatives together with Resveratrol (RSV), a multifunctional natural product was screened; nine compounds (28, 29, 33, 35, 36, 38, 39, 41 and 42) have showed promising micro and macrofilaricidal activities and four of them (28, 39, 41 and 42) showed better effectiveness than RSV. In the treated parasites apoptosis was established by DNA laddering, in situ DNA fragmentation and FACS analysis. The generation of ROS in the treated parasites was indicated by the depletion in the level of GSH, GR and GST activity and elevation of SOD, catalase, GPx activity and superoxide anion and H2O2 level. Along with the ROS generation and oxidative stress, the decreased expression of anti-apoptotic ced-9 gene and increased expression of nematode specific pro-apoptotic genes, egl-1, ced-4 and ced-3 at the level of transcription and translation level; the up-regulation of caspase-3 activity and involvement of caspase-8,9,3, cytochrome-c and PARP were also observed and which denotes the probable existence of both extrinsic and intrinsic pathways apoptosis in parasitic nematodes. This observation is reported first time and thus it confirmed the mode of action and effectiveness of the compounds. Further, the comparative bioavailability-pharmacokinetics studies showed that compound 28 possesses comparable properties with Ivermectin. This study will certainly intensify our understanding of the pharmacological importance of trans

  1. A survey of canine filarial diseases of veterinary and public health significance in India

    PubMed Central

    2010-01-01

    Background Dirofilaria spp., Acanthocheilonema spp. and Brugia spp. have all been reported in Indian dogs. In previous studies, diagnosis was made by morphological identification only. This is the first geographically stratified cross-sectional study in India to determine the prevalence and geographical distribution of canine filarial species of veterinary and public health importance, using a combination of conventional and molecular diagnostic techniques. Results A total of 139 from 525 dogs (26.5%; 95% CI 22.7, 30.3) were positive for microfilariae. The most common species of canine filaria identified in this study was A. reconditum (9.3%) followed by D. repens (6.7%) and D. immitis (1.5%). Three out of 525 dogs were found to have mixed infections on PCR. The morphological and molecular evidence on the sequence of the 18S gene and phylogenetic analysis of the ITS-2 region provided strong evidence that the canine microfilariae discovered in the Himalayan city of Ladakh belong to a novel species of Acanthocheilonema. Two dogs in Ladakh were also found to have mixed infections of the novel species described above and a unique microfilaria which morphologically resembled Microfilaria auquieri Foley, 1921. Conclusions At least six species of filarial nematode are now known to infect dogs in India, two of which were reported for the first time in this study. The study also confirms and extends the geographical distribution of canine heartworm (D. immitis) which overlaps with D. repens, emphasising the importance for veterinary clinicians and diagnostic laboratories to utilise immunodiagnostic tests that will not cross-react between those two filarial species. From a public health viewpoint, the distribution and prevalences of these nematodes warrant an appropriate prophylaxis to be administered to dogs. PMID:20377864

  2. Molecular and phylogenetic analysis of the filarial nematode Micipsella numidica from the hare Lepus europaeus in Italy.

    PubMed

    Gabrielli, S; Galuppi, R; Fraulo, M; Savini, F; Morandi, B; Cancrini, G; Poglayen, G

    2016-07-01

    The genus Micipsella comprises three species of filariae to date identified in lagomorphs only, whereas the other genera belonging to the subfamily Splendidofilariinae are described as parasites of birds, reptiles and mammals. In the present study seven specimens of Micipsella numidica (Seurat, 1917), collected from the hare Lepus europaeus in Italy, were characterized genetically by molecular amplification of the mitochondrial genes (12S rDNA; cox1) and the 5S rDNA gene spacer region. Phylogenetic trees inferred using available sequences from filariae and those identified in this study evidenced a close relationship between M. numidica and Splendidofilariinae of other mammals and reptiles (Rumenfilaria andersoni and Madathamugadia hiepei). The present findings, apart from adding new data about the hosts in Italy, support the taxonomic position of M. numidica and highlight the substantial biological and molecular differences existing between Splendidofilariinae and other Onchocercidae. The study also contributes to our knowledge of the molecular/genetic diagnosis of filarial parasites of veterinary and medical concern in any vertebrate or invertebrate host.

  3. Analysis of gene expression from the Wolbachia genome of a filarial nematode supports both metabolic and defensive roles within the symbiosis

    PubMed Central

    Darby, Alistair C.; Armstrong, Stuart D.; Bah, Germanus S.; Kaur, Gaganjot; Hughes, Margaret A.; Kay, Suzanne M.; Koldkjær, Pia; Rainbow, Lucille; Radford, Alan D.; Blaxter, Mark L.; Tanya, Vincent N.; Trees, Alexander J.; Cordaux, Richard; Wastling, Jonathan M.; Makepeace, Benjamin L.

    2012-01-01

    The α-proteobacterium Wolbachia is probably the most prevalent, vertically transmitted symbiont on Earth. In contrast with its wide distribution in arthropods, Wolbachia is restricted to one family of animal-parasitic nematodes, the Onchocercidae. This includes filarial pathogens such as Onchocerca volvulus, the cause of human onchocerciasis, or river blindness. The symbiosis between filariae and Wolbachia is obligate, although the basis of this dependency is not fully understood. Previous studies suggested that Wolbachia may provision metabolites (e.g., haem, riboflavin, and nucleotides) and/or contribute to immune defense. Importantly, Wolbachia is restricted to somatic tissues in adult male worms, whereas females also harbor bacteria in the germline. We sought to characterize the nature of the symbiosis between Wolbachia and O. ochengi, a bovine parasite representing the closest relative of O. volvulus. First, we sequenced the complete genome of Wolbachia strain wOo, which revealed an inability to synthesize riboflavin de novo. Using RNA-seq, we also generated endobacterial transcriptomes from male soma and female germline. In the soma, transcripts for membrane transport and respiration were up-regulated, while the gonad exhibited enrichment for DNA replication and translation. The most abundant Wolbachia proteins, as determined by geLC-MS, included ligands for mammalian Toll-like receptors. Enzymes involved in nucleotide synthesis were dominant among metabolism-related proteins, whereas the haem biosynthetic pathway was poorly represented. We conclude that Wolbachia may have a mitochondrion-like function in the soma, generating ATP for its host. Moreover, the abundance of immunogenic proteins in wOo suggests a role in diverting the immune system toward an ineffective antibacterial response. PMID:22919073

  4. Analysis of gene expression from the Wolbachia genome of a filarial nematode supports both metabolic and defensive roles within the symbiosis.

    PubMed

    Darby, Alistair C; Armstrong, Stuart D; Bah, Germanus S; Kaur, Gaganjot; Hughes, Margaret A; Kay, Suzanne M; Koldkjær, Pia; Rainbow, Lucille; Radford, Alan D; Blaxter, Mark L; Tanya, Vincent N; Trees, Alexander J; Cordaux, Richard; Wastling, Jonathan M; Makepeace, Benjamin L

    2012-12-01

    The α-proteobacterium Wolbachia is probably the most prevalent, vertically transmitted symbiont on Earth. In contrast with its wide distribution in arthropods, Wolbachia is restricted to one family of animal-parasitic nematodes, the Onchocercidae. This includes filarial pathogens such as Onchocerca volvulus, the cause of human onchocerciasis, or river blindness. The symbiosis between filariae and Wolbachia is obligate, although the basis of this dependency is not fully understood. Previous studies suggested that Wolbachia may provision metabolites (e.g., haem, riboflavin, and nucleotides) and/or contribute to immune defense. Importantly, Wolbachia is restricted to somatic tissues in adult male worms, whereas females also harbor bacteria in the germline. We sought to characterize the nature of the symbiosis between Wolbachia and O. ochengi, a bovine parasite representing the closest relative of O. volvulus. First, we sequenced the complete genome of Wolbachia strain wOo, which revealed an inability to synthesize riboflavin de novo. Using RNA-seq, we also generated endobacterial transcriptomes from male soma and female germline. In the soma, transcripts for membrane transport and respiration were up-regulated, while the gonad exhibited enrichment for DNA replication and translation. The most abundant Wolbachia proteins, as determined by geLC-MS, included ligands for mammalian Toll-like receptors. Enzymes involved in nucleotide synthesis were dominant among metabolism-related proteins, whereas the haem biosynthetic pathway was poorly represented. We conclude that Wolbachia may have a mitochondrion-like function in the soma, generating ATP for its host. Moreover, the abundance of immunogenic proteins in wOo suggests a role in diverting the immune system toward an ineffective antibacterial response.

  5. Effects of Doxycycline on gene expression in Wolbachia and Brugia malayi adult female worms in vivo

    PubMed Central

    2012-01-01

    Background Most filarial nematodes contain Wolbachia symbionts. The purpose of this study was to examine the effects of doxycycline on gene expression in Wolbachia and adult female Brugia malayi. Methods Brugia malayi infected gerbils were treated with doxycycline for 6-weeks. This treatment largely cleared Wolbachia and arrested worm reproduction. RNA recovered from treated and control female worms was labeled by random priming and hybridized to the Version 2- filarial microarray to obtain expression profiles. Results and discussion Results showed significant changes in expression for 200 Wolbachia (29% of Wolbachia genes with expression signals in untreated worms) and 546 B. malayi array elements after treatment. These elements correspond to known genes and also to novel genes with unknown biological functions. Most differentially expressed Wolbachia genes were down-regulated after treatment (98.5%). In contrast, doxycycline had a mixed effect on B. malayi gene expression with many more genes being significantly up-regulated after treatment (85% of differentially expressed genes). Genes and processes involved in reproduction (gender-regulated genes, collagen, amino acid metabolism, ribosomal processes, and cytoskeleton) were down-regulated after doxycycline while up-regulated genes and pathways suggest adaptations for survival in response to stress (energy metabolism, electron transport, anti-oxidants, nutrient transport, bacterial signaling pathways, and immune evasion). Conclusions Doxycycline reduced Wolbachia and significantly decreased bacterial gene expression. Wolbachia ribosomes are believed to be the primary biological target for doxycycline in filarial worms. B. malayi genes essential for reproduction, growth and development were also down-regulated; these changes are consistent with doxycycline effects on embryo development and reproduction. On the other hand, many B. malayi genes involved in energy production, electron-transport, metabolism, anti

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

    PubMed

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

    2015-01-01

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

  7. Detection of Circulating Parasite-Derived MicroRNAs in Filarial Infections

    PubMed Central

    Tritten, Lucienne; Burkman, Erica; Moorhead, Andrew; Satti, Mohammed; Geary, James; Mackenzie, Charles; Geary, Timothy

    2014-01-01

    Filarial nematodes cause chronic and profoundly debilitating diseases in both humans and animals. Applications of novel technology are providing unprecedented opportunities to improve diagnosis and our understanding of the molecular basis for host-parasite interactions. As a first step, we investigated the presence of circulating miRNAs released by filarial nematodes into the host bloodstream. miRNA deep-sequencing combined with bioinformatics revealed over 200 mature miRNA sequences of potential nematode origin in Dirofilaria immitis-infected dog plasma in two independent analyses, and 21 in Onchocerca volvulus-infected human serum. Total RNA obtained from D. immitis-infected dog plasma was subjected to stem-loop RT-qPCR assays targeting two detected miRNA candidates, miR-71 and miR-34. Additionally, Brugia pahangi-infected dog samples were included in the analysis, as these miRNAs were previously detected in extracts prepared from this species. The presence of miR-71 and miR-34 discriminated infected samples (both species) from uninfected samples, in which no specific miRNA amplification occurred. However, absolute miRNA copy numbers were not significantly correlated with microfilaraemia for either parasite. This may be due to the imprecision of mf counts to estimate infection intensity or to miRNA contributions from the unknown number of adult worms present. Nonetheless, parasite-derived circulating miRNAs are found in plasma or serum even for those species that do not live in the bloodstream. PMID:25033073

  8. Filarial Worms Reduce Plasmodium Infectivity in Mosquitoes

    PubMed Central

    Aliota, Matthew T.; Chen, Cheng-Chen; Dagoro, Henry; Fuchs, Jeremy F.; Christensen, Bruce M.

    2011-01-01

    Background 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). Methodology/Principal Findings 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

  9. Evaluation of immune response elicited by inulin as an adjuvant with filarial antigens in mice model.

    PubMed

    Mahalakshmi, N; Aparnaa, R; Kaliraj, P

    2014-10-01

    Filariasis caused by infectious parasitic nematodes has been identified as the second leading source of permanent and long-term disability in Sub-Saharan Africa, Asia and Latin America. Several vaccine candidates were identified from infective third-stage larvae (L3) which involves in the critical transition from arthropod to human. Hitherto studies of these antigens in combination with alum adjuvant have shown to elicit its characteristic Th2 responses. Inulin is a safe, non-toxic adjuvant that principally stimulates the innate immune response through the alternative complement pathway. In the present study, the immune response elicited by inulin and alum as adjuvants were compared with filarial antigens from different aetiological agents: secreted larval acidic protein 1 (SLAP1) from Onchocerca volvulus and venom allergen homologue (VAH) from Brugia malayi as single or as cocktail vaccines in mice model. The study revealed that inulin can induce better humoral response against these antigens than alum adjuvant. Antibody isotyping disclosed inulin's ability to elevate the levels of IgG2a and IgG3 antibodies which mediates in complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC), respectively, in mice. Splenocyte analysis showed that T cells prestimulated with inulin have higher stimulation index (P < 0.05) than alum except for BmVAH antigen. In vitro ADCC assay showed that inulin formulation had induced higher cytotoxicity with filarial antigens (as single P < 0.01 and as cocktail P < 0.05, respectively) than alum. The results had confirmed the capability of inulin to deplete the levels of Treg and brought a balance in Th1/Th2 arms against filarial antigens in mice.

  10. Identification and characterization of nematode specific protective epitopes of Brugia malayi TRX towards development of synthetic vaccine construct for lymphatic filariasis.

    PubMed

    Madhumathi, Jayaprakasam; Prince, Prabhu Rajaiah; Anugraha, Gandhirajan; Kiran, Pote; Rao, Donthamsetty Nageswara; Reddy, Maryada Venkata Rami; Kaliraj, Perumal

    2010-07-12

    Although multi-epitope vaccines have been evaluated for various diseases, they have not yet been investigated for lymphatic filariasis. Here, we report for the first time identification of two immunodominant B epitopes (TRXP1 and TRXP2) from the antioxidant Brugia malayi thioredoxin by studying their immune responses in mice model and human subjects. TRXP1 was also found to harbor a T epitope recognized by human PBMCs and mice splenocytes. Further, the epitopic peptides were synthesized as a single peptide conjugate (PC1) and their prophylactic efficacy was tested in a murine model of filariasis with L3 larvae. PC1 conferred a significantly high protection (75.14%) (P < 0.0001) compared to control (3.7%) and recombinant TRX (63.03%) (P < 0.018) in experimental filariasis. Our results suggest that multi-epitope vaccines could be a promising strategy in the control of lymphatic filariasis.

  11. Effect of immunostimulatory oligodeoxynucleotides on host responses and the establishment of Brugia pahangi in Mongolian gerbils (Meriones unguiculatus).

    PubMed

    Chirgwin, Sharon R; Nowling, Jena M; Coleman, Sharon U; Klei, Thomas R

    2003-06-01

    Infection of humans with filarial parasites has long been associated with the maintenance of a dominant Th2-type host immune response. This is reflected by increases in interleukin (IL)-4- and IL-5-producing T cells, elevated immunoglobulin (Ig)E and IgG4 levels, and a pronounced eosinophilia. The Mongolian gerbil (Meriones unguiculatus) is permissive for the filarial nematodes Brugia malayi and B. pahangi. As in humans, persistent microfilaremic infections of gerbils with Brugia spp. results in increases in Th2 cytokines such as IL-4 and IL-5. The association of dominant Th2 cytokine profiles with the maintenance of infection suggests that the introduction of Brugia spp. into a strongly Th1-biased environment may adversely affect parasite establishment. Indeed, studies conducted in mice with B. malayi suggest that depleting Th1 effectors such as interferon (IFN)-gamma and nitric oxide results in increased worm recoveries. In the present studies, the Mongolian gerbil was used as a model to investigate the effect of a dominant Th1 cytokine environment on the establishment of B. pahangi. Intraperitoneal (i.p.) administration of immunostimulatory oligodeoxynucleotide (IS ODN) induced the production of IFN-gamma in the peritoneal exudate cells and spleen of gerbils. The presence of IFN-gamma at the time of B. pahangi infection did result in an altered host immune response to B. pahangi. Gerbils that received IS ODN before i.p. B. pahangi infections showed lower levels of the Th2-type cytokines IL-4 and IL-5, compared with animals that received B. pahangi alone (0 + Bp). This alteration in cytokine profile, however, did not alter the establishment or development of B. pahangi in the peritoneal cavity. Furthermore, there was no difference in the granulomatous response of gerbils to soluble adult B. pahangi antigen bound to beads embolized in their lungs, regardless of treatment group, suggesting that IL-4 and IL-5 are not essential contributors to the systemic host

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

    PubMed Central

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

    2015-01-01

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

  13. Filarial huge splenomegaly dramatically regressed by anti-filarial medication: A rare clinical scenario.

    PubMed

    Basu, Ayan; Kumar, Arvind; Manchanda, Smita; Wig, Naveet

    2017-08-01

    Lymphatic filariasis is caused by nematodes Wuchereria bancrofti, Brugia malayi and Brugia timori. Lymphatic filariasis is a spectrum of illness and can manifest as, asymptomatic microfilaraemia, acute lymphatic filariasis (lymphangitis and lymphoedema), chronic lymphoedema, elephantiasis, hydrocele, tropical pulmonary eosinophilia and some systemic manifestations which involves joint, heart, kidney, nerve, etc. We here present a case of huge splenomegaly caused by lymphatic filariasis which is a rare presentation and only few cases had been reported in the world literature so far. After treatment of filariasis spleen size was reduced dramatically and patient is doing well even after 6 months of follow up after therapy.

  14. Stage- and Gender-Specific Proteomic Analysis of Brugia malayi Excretory-Secretory Products

    PubMed Central

    Moreno, Yovany; Geary, Timothy G.

    2008-01-01

    Introduction While we lack a complete understanding of the molecular mechanisms by which parasites establish and achieve protection from host immune responses, it is accepted that many of these processes are mediated by products, primarily proteins, released from the parasite. Parasitic nematodes occur in different life stages and anatomical compartments within the host. Little is known about the composition and variability of products released at different developmental stages and their contribution to parasite survival and progression of the infection. Methodology/Principal Findings To gain a deeper understanding on these aspects, we collected and analyzed through 1D-SDS PAGE and LC-MS/MS the Excretory-Secretory Products (ESP) of adult female, adult male and microfilariae of the filarial nematode Brugia malayi, one of the etiological agents of human lymphatic filariasis. This proteomic analysis led to the identification of 228 proteins. The list includes 76 proteins with unknown function as well as also proteins with potential immunoregulatory properties, such as protease inhibitors, cytokine homologues and carbohydrate-binding proteins. Larval and adult ESP differed in composition. Only 32 proteins were shared between all three stages/genders. Consistent with this observation, different gene ontology profiles were associated with the different ESP. Conclusions/Significance A comparative analysis of the proteins released in vitro by different forms of a parasitic nematode dwelling in the same host is presented. The catalog of secreted proteins reflects different stage- and gender-specific related processes and different strategies of immune evasion, providing valuable insights on the contribution of each form of the parasite for establishing the host–parasite interaction. PMID:18958170

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

    PubMed

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

    2010-11-16

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

  16. Prior killing of intracellular bacteria Wolbachia reduces inflammatory reactions and improves antifilarial efficacy of diethylcarbamazine in rodent model of Brugia malayi.

    PubMed

    Shakya, Shilpy; Bajpai, Preeti; Sharma, Sharad; Misra-Bhattacharya, Shailja

    2008-04-01

    The discovery of the endosymbiont Wolbachia, which has a mutualistic relationship with filarial nematodes, and its importance in filarial parasite biology has provided a lead for developing novel chemotherapeutic agents against human filariasis. Wolbachia also appears to be involved in immunopathological responses as well as adverse reactions after antifilarial therapy. The aim of the present study was to explore the potential of administering anti-Wolbachial therapy before antifilarial treatment to improve the filaricidal efficacy of the present-day filaricide diethylcarbamazine. An additional objective was to minimize host inflammatory reactions using a rodent model Mastomys coucha and Meriones unguiculatus infected with human lymphatic filariid Brugia malayi. We observed: (1) a 40-day treatment schedule of tetracycline alone resulted in delayed reduction in microfilaraemia and a low degree of macrofilaricidal efficacy; (2) tetracycline therapy followed by 100 mg/kg diethylcarbamazine (DEC) x5 days led to marked reduction in microfilaraemia from day 48 onward after initiation of treatment. The combination treatment also brought about approximately 70% death of adult B. malayi and sterilization of 82.3% of the surviving female worms, thus exhibiting remarkable enhancement in the antifilarial activity of DEC; (3) tissue inflammatory reactions and pathogenesis were significantly reduced as observed by histopathology, and peritoneal macrophage mediated oxidative burst shown by fluorescence-activated cell sorting (FACS) analysis using dichlorofluorescein diacetate (DCF-DA); and (4) the characteristic filarial antigen-specific and mitogen-specific cellular unresponsiveness was significantly reversed, possibly due to marked clearance of microfilaraemia. It is therefore advisable to give an anti-Wolbachial antibiotic trial before starting antifilarial therapy to achieve maximum benefits.

  17. The astacin metalloprotease moulting enzyme NAS-36 is required for normal cuticle ecdysis in free-living and parasitic nematodes.

    PubMed

    Stepek, Gillian; McCormack, Gillian; Birnie, Andrew J; Page, Antony P

    2011-02-01

    Nematodes represent one of the most abundant and species-rich groups of animals on the planet, with parasitic species causing chronic, debilitating infections in both livestock and humans worldwide. The prevalence and success of the nematodes is a direct consequence of the exceptionally protective properties of their cuticle. The synthesis of this cuticle is a complex multi-step process, which is repeated 4 times from hatchling to adult and has been investigated in detail in the free-living nematode, Caenorhabditis elegans. This process is known as moulting and involves numerous enzymes in the synthesis and degradation of the collagenous matrix. The nas-36 and nas-37 genes in C. elegans encode functionally conserved enzymes of the astacin metalloprotease family which, when mutated, result in a phenotype associated with the late-stage moulting defects, namely the inability to remove the preceding cuticle. Extensive genome searches in the gastrointestinal nematode of sheep, Haemonchus contortus, and in the filarial nematode of humans, Brugia malayi, identified NAS-36 but not NAS-37 homologues. Significantly, the nas-36 gene from B. malayi could successfully complement the moult defects associated with C. elegans nas-36, nas-37 and nas-36/nas-37 double mutants, suggesting a conserved function for NAS-36 between these diverse nematode species. This conservation between species was further indicated when the recombinant enzymes demonstrated a similar range of inhibitable metalloprotease activities.

  18. Absence of Wolbachia endobacteria in Sri Lankan isolates of the nematode parasite of animals Setaria digitata.

    PubMed

    Voronin, Denis; Abeykoon, A M L L; Gunawardene, Y I Silva; Dassanayake, Ranil S

    2015-01-30

    Setaria digitata is an animal filarial parasite with natural hosts of cattle and buffaloes that causes mild disease conditions. Infection of non-permissive hosts such as goats, sheep and horses, by this nematode can cause cerebrospinal nematodiasis that leads to lumbar paralysis and the eventual death of the animals and inflicts considerable economic losses on livestock farmers. Wolbachia are obligate mutualistic endosymbionts for some filarial nematodes and are currently being targeted for the control of diseases caused by these parasites. However, little is known about the occurrence of this endosymbiont in the Setariidae family. In this work, worms collected from infected cattle in Sri Lanka were morphologically identified as S. digitata and tested for the presence of Wolbachia by PCR screening using the WSP- and Wolbachia-specific 16S rRNA and multilocus sequence typing primers that were designed to amplify the gatB, coxA, hcpA, ftsZ and fbpA sequences of Wolbachia. The presence of endobacteria in S. digitata was also examined by whole-mount immunofluorescence staining of the parasites and transmission electron microscopic studies. These analyses did not produce evidence of presence of Wolbachia or any other endosymbiotic bacteria in S. digitata, whereas such evidence was found in Brugia malayi, which was used as a positive control in this study. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Homology Modeling of NAD+-Dependent DNA Ligase of the Wolbachia Endosymbiont of Brugia malayi and Its Drug Target Potential Using Dispiro-Cycloalkanones

    PubMed Central

    Shrivastava, Nidhi; Nag, Jeetendra K.; Pandey, Jyoti; Tripathi, Rama Pati; Shah, Priyanka; Siddiqi, Mohammad Imran

    2015-01-01

    Lymphatic filarial nematodes maintain a mutualistic relationship with the endosymbiont Wolbachia. Depletion of Wolbachia produces profound defects in nematode development, fertility, and viability and thus has great promise as a novel approach for treating filarial diseases. NAD+-dependent DNA ligase is an essential enzyme of DNA replication, repair, and recombination. Therefore, in the present study, the antifilarial drug target potential of the NAD+-dependent DNA ligase of the Wolbachia symbiont of Brugia malayi (wBm-LigA) was investigated using dispiro-cycloalkanone compounds. Dispiro-cycloalkanone specifically inhibited the nick-closing and cohesive-end ligation activities of the enzyme without inhibiting human or T4 DNA ligase. The mode of inhibition was competitive with the NAD+ cofactor. Docking studies also revealed the interaction of these compounds with the active site of the target enzyme. The adverse effects of these inhibitors were observed on adult and microfilarial stages of B. malayi in vitro, and the most active compounds were further monitored in vivo in jirds and mastomys rodent models. Compounds 1, 2, and 5 had severe adverse effects in vitro on the motility of both adult worms and microfilariae at low concentrations. Compound 2 was the best inhibitor, with the lowest 50% inhibitory concentration (IC50) (1.02 μM), followed by compound 5 (IC50, 2.3 μM) and compound 1 (IC50, 2.9 μM). These compounds also exhibited the same adverse effect on adult worms and microfilariae in vivo (P < 0.05). These compounds also tremendously reduced the wolbachial load, as evident by quantitative real-time PCR (P < 0.05). wBm-LigA thus shows great promise as an antifilarial drug target, and dispiro-cycloalkanone compounds show great promise as antifilarial lead candidates. PMID:25845868

  20. Homology modeling of NAD+-dependent DNA ligase of the Wolbachia endosymbiont of Brugia malayi and its drug target potential using dispiro-cycloalkanones.

    PubMed

    Shrivastava, Nidhi; Nag, Jeetendra K; Pandey, Jyoti; Tripathi, Rama Pati; Shah, Priyanka; Siddiqi, Mohammad Imran; Misra-Bhattacharya, Shailja

    2015-07-01

    Lymphatic filarial nematodes maintain a mutualistic relationship with the endosymbiont Wolbachia. Depletion of Wolbachia produces profound defects in nematode development, fertility, and viability and thus has great promise as a novel approach for treating filarial diseases. NAD(+)-dependent DNA ligase is an essential enzyme of DNA replication, repair, and recombination. Therefore, in the present study, the antifilarial drug target potential of the NAD(+)-dependent DNA ligase of the Wolbachia symbiont of Brugia malayi (wBm-LigA) was investigated using dispiro-cycloalkanone compounds. Dispiro-cycloalkanone specifically inhibited the nick-closing and cohesive-end ligation activities of the enzyme without inhibiting human or T4 DNA ligase. The mode of inhibition was competitive with the NAD(+) cofactor. Docking studies also revealed the interaction of these compounds with the active site of the target enzyme. The adverse effects of these inhibitors were observed on adult and microfilarial stages of B. malayi in vitro, and the most active compounds were further monitored in vivo in jirds and mastomys rodent models. Compounds 1, 2, and 5 had severe adverse effects in vitro on the motility of both adult worms and microfilariae at low concentrations. Compound 2 was the best inhibitor, with the lowest 50% inhibitory concentration (IC50) (1.02 μM), followed by compound 5 (IC50, 2.3 μM) and compound 1 (IC50, 2.9 μM). These compounds also exhibited the same adverse effect on adult worms and microfilariae in vivo (P < 0.05). These compounds also tremendously reduced the wolbachial load, as evident by quantitative real-time PCR (P < 0.05). wBm-LigA thus shows great promise as an antifilarial drug target, and dispiro-cycloalkanone compounds show great promise as antifilarial lead candidates.

  1. Zoonotic aspects of filarial infections in man

    PubMed Central

    Dissanaike, A. S.

    1979-01-01

    This article gives an account of the filarial parasites found in man and their potential transmissibility to and from other vertebrate animals under natural and experimental conditions. Those species that are regarded as being primarily parasites of other vertebrates, but which also infect man, are then dealt with in greater detail. These include the subperiodic strain of Brugia malayi and perhaps also B. pahangi, both of which are found in wild and domestic carnivores and monkeys, and Dirofilaria species of dogs and racoons. The Brugia parasites develop to maturity with the production of microfilaraemia and clinical manifestations in man similar to those caused by periodic B. malayi in man. Human dirofilariasis, on the other hand, represents a transmission cul-de-sac for the parasite. Clinical manifestations are mild or absent and generally the worms do not mature and, even if they do, they rarely give rise to microfilaraemia. D. immitis causes pulmonary dirofilariasis, and D. repens and D. tenuis give rise to subcutaneous nodules in man. The diagnosis of dirofilariasis depends on an awareness of the infection in the animal reservoirs and of the possibility of man being exposed to bites of infected vectors. ImagesFig. 2Fig. 3Fig. 4Fig. 5Fig. 6 PMID:314349

  2. Zoonotic aspects of filarial infections in man.

    PubMed

    Dissanaike, A S

    1979-01-01

    This article gives an account of the filarial parasites found in man and their potential transmissibility to and from other vertebrate animals under natural and experimental conditions.Those species that are regarded as being primarily parasites of other vertebrates, but which also infect man, are then dealt with in greater detail. These include the subperiodic strain of Brugia malayi and perhaps also B. pahangi, both of which are found in wild and domestic carnivores and monkeys, and Dirofilaria species of dogs and racoons.The Brugia parasites develop to maturity with the production of microfilaraemia and clinical manifestations in man similar to those caused by periodic B. malayi in man. Human dirofilariasis, on the other hand, represents a transmission cul-de-sac for the parasite. Clinical manifestations are mild or absent and generally the worms do not mature and, even if they do, they rarely give rise to microfilaraemia. D. immitis causes pulmonary dirofilariasis, and D. repens and D. tenuis give rise to subcutaneous nodules in man. The diagnosis of dirofilariasis depends on an awareness of the infection in the animal reservoirs and of the possibility of man being exposed to bites of infected vectors.

  3. Conservation of long-range synteny and microsynteny between the genomes of two distantly related nematodes

    PubMed Central

    Guiliano, DB; Hall, N; Jones, SJM; Clark, LN; Corton, CH; Barrell, BG; Blaxter, ML

    2002-01-01

    Background Comparisons between the genomes of the closely related nematodes Caenorhabditis elegans and Caenorhabditis briggsae reveal high rates of rearrangement, with a bias towards within-chromosome events. To assess whether this pattern is true of nematodes in general, we have used genome sequence to compare two nematode species that last shared a common ancestor approximately 300 million years ago: the model C. elegans and the filarial parasite Brugia malayi. Results An 83 kb region flanking the gene for Bm-mif-1 (macrophage migration inhibitory factor, a B. malayi homolog of a human cytokine) was sequenced. When compared to the complete genome of C. elegans, evidence for conservation of long-range synteny and microsynteny was found. Potential C. elegans orthologs for II of the 12 protein-coding genes predicted in the B. malayi sequence were identified. Ten of these orthologs were located on chromosome I, with eight clustered in a 2.3 Mb region. While several, relatively local, intrachromosomal rearrangements have occurred, the order, composition, and configuration of two gene clusters, each containing three genes, was conserved. Comparison of B. malayi BAC-end genome survey sequence to C. elegans also revealed a bias towards intrachromosome rearrangements. Conclusions We suggest that intrachromosomal rearrangement is a major force driving chromosomal organization in nematodes, but is constrained by the interdigitation of functional elements of neighboring genes. PMID:12372145

  4. Human Leukocytes Kill Brugia malayi Microfilariae Independently of DNA-Based Extracellular Trap Release

    PubMed Central

    McCoy, Ciaran J.; Reaves, Barbara J.; Giguère, Steeve; Coates, Ruby; Rada, Balázs

    2017-01-01

    Background Wuchereria bancrofti, Brugia malayi and Brugia timori infect over 100 million people worldwide and are the causative agents of lymphatic filariasis. Some parasite carriers are amicrofilaremic whilst others facilitate mosquito-based disease transmission through blood-circulating microfilariae (Mf). Recent findings, obtained largely from animal model systems, suggest that polymorphonuclear leukocytes (PMNs) contribute to parasitic nematode-directed type 2 immune responses. When exposed to certain pathogens PMNs release extracellular traps (NETs) in the form of chromatin loaded with various antimicrobial molecules and proteases. Principal findings In vitro, PMNs expel large amounts of NETs that capture but do not kill B. malayi Mf. NET morphology was confirmed by fluorescence imaging of worm-NET aggregates labelled with DAPI and antibodies to human neutrophil elastase, myeloperoxidase and citrullinated histone H4. A fluorescent, extracellular DNA release assay was used to quantify and observe Mf induced NETosis over time. Blinded video analyses of PMN-to-worm attachment and worm survival during Mf-leukocyte co-culture demonstrated that DNase treatment eliminates PMN attachment in the absence of serum, autologous serum bolsters both PMN attachment and PMN plus peripheral blood mononuclear cell (PBMC) mediated Mf killing, and serum heat inactivation inhibits both PMN attachment and Mf killing. Despite the effects of heat inactivation, the complement inhibitor compstatin did not impede Mf killing and had little effect on PMN attachment. Both human PMNs and monocytes, but not lymphocytes, are able to kill B. malayi Mf in vitro and NETosis does not significantly contribute to this killing. Leukocytes derived from presumably parasite-naïve U.S. resident donors vary in their ability to kill Mf in vitro, which may reflect the pathological heterogeneity associated with filarial parasitic infections. Conclusions/Significance Human innate immune cells are able to

  5. Transforming growth factor-beta expression by host cells is elicited locally by the filarial nematode Onchocerca volvulus in hyporeactive patients independently from Wolbachia.

    PubMed

    Korten, Simone; Kaifi, Jussuf T; Büttner, Dietrich W; Hoerauf, Achim

    2010-07-01

    Transforming growth factor-beta (TGF-beta) is a key cytokine in immune regulation, cell differentiation, development, wound healing, and tissue remodelling. It mediates immunosuppression in filarial infections facilitating parasite persistence, while attenuating immunopathology, which is induced by migrating microfilariae. Immunosuppression rises with parasite burden, but it remains unknown whether filariae elicit local release of immunosuppressive cytokines. Therefore, using immunohistology, we investigated the expression of stable, released latent TGF-beta1 in subcutaneous nodules from highly infected, hyporeactive onchocerciasis patients, harbouring adult Onchocerca volvulus. Since many cell types produce TGF-beta, we elucidated the cellular source, distribution and dependency on the worms' sex, productivity and vitality. We found TGF-beta1 to be abundantly expressed by T cells, plasma/B cells, macrophages, mast cells, fibrocytes, and vascular endothelial cells, particularly in onchocercomas with productive or previously productive females, damaged, dead and resorbed adult worms or microfilariae. We conclude TGF-beta to be antigen induced by the filariae since expression was scarce around subcutaneous arthropods or cholesterol crystals in onchocercomas. Enhanced expression after ivermectin or endobacteria-depleting doxycycline treatment indicates induction to depend on filariae and not on Wolbachia endobacteria. TGF-beta(+) cells were reduced in HIV co-infection. This finding of local and sustained TGF-beta induction by vital and dead filariae, untreated and after treatment, adds new aspects to immunomodulation by helminths.

  6. Removing the needle from the haystack: Enrichment of Wolbachia endosymbiont transcripts from host nematode RNA by Cappable-seq™.

    PubMed

    Luck, Ashley N; Slatko, Barton E; Foster, Jeremy M

    2017-01-01

    Efficient transcriptomic sequencing of microbial mRNA derived from host-microbe associations is often compromised by the much lower relative abundance of microbial RNA in the mixed total RNA sample. One solution to this problem is to perform extensive sequencing until an acceptable level of transcriptome coverage is obtained. More cost-effective methods include use of prokaryotic and/or eukaryotic rRNA depletion strategies, sometimes in conjunction with depletion of polyadenylated eukaryotic mRNA. Here, we report use of Cappable-seq™ to specifically enrich, in a single step, Wolbachia endobacterial mRNA transcripts from total RNA prepared from the parasitic filarial nematode, Brugia malayi. The obligate Wolbachia endosymbiont is a proven drug target for many human filarial infections, yet the precise nature of its symbiosis with the nematode host is poorly understood. Insightful analysis of the expression levels of Wolbachia genes predicted to underpin the mutualistic association and of known drug target genes at different life cycle stages or in response to drug treatments is typically challenged by low transcriptomic coverage. Cappable-seq resulted in up to ~ 5-fold increase in the number of reads mapping to Wolbachia. On average, coverage of Wolbachia transcripts from B. malayi microfilariae was enriched ~40-fold by Cappable-seq. Additionally, this method has an additional benefit of selectively removing abundant prokaryotic ribosomal RNAs.The deeper microbial transcriptome sequencing afforded by Cappable-seq facilitates more detailed characterization of gene expression levels of pathogens and symbionts present in animal tissues.

  7. Modelling variability in lymphatic filariasis: macrofilarial dynamics in the Brugia pahangi--cat model.

    PubMed Central

    Michael, E; Grenfell, B T; Isham, V S; Denham, D A; Bundy, D A

    1998-01-01

    A striking feature of lymphatic filariasis is the considerable heterogeneity in infection burden observed between hosts, which greatly complicates the analysis of the population dynamics of the disease. Here, we describe the first application of the moment closure equation approach to model the sources and the impact of this heterogeneity for macrofilarial population dynamics. The analysis is based on the closest laboratory equivalent of the life cycle and immunology of infection in humans--cats chronically infected with the filarial nematode Brugia pahangi. Two sets of long-term experiments are analysed: hosts given either single primary infections or given repeat infections. We begin by quantifying changes in the mean and aggregation of adult parasites (inversely measured by the negative binomial parameter, kappa in cohorts of hosts using generalized linear models. We then apply simple stochastic models to interpret observed patterns. The models and empirical data indicate that parasite aggregation tracks the decline in the mean burden with host age in primary infections. Conversely, in repeat infections, aggregation increases as the worm burden declines with experience of infection. The results show that the primary infection variability is consistent with heterogeneities in parasite survival between hosts. By contrast, the models indicate that the reduction in parasite variability with time in repeat infections is most likely due to the 'filtering' effect of a strong, acquired immune response, which gradually acts to remove the initial variability generated by heterogeneities in larval mortality. We discuss this result in terms of the homogenizing effect of host immunity-driven density-dependence on macrofilarial burden in older hosts. PMID:9474798

  8. Polyanhydride Nanoparticle Delivery Platform Dramatically Enhances Killing of Filarial Worms

    PubMed Central

    Binnebose, Andrea M.; Haughney, Shannon L.; Martin, Richard; Imerman, Paula M.; Narasimhan, Balaji; Bellaire, Bryan H.

    2015-01-01

    Filarial diseases represent a significant social and economic burden to over 120 million people worldwide and are caused by endoparasites that require the presence of symbiotic bacteria of the genus Wolbachia for fertility and viability of the host parasite. Targeting Wolbachia for elimination is a therapeutic approach that shows promise in the treatment of onchocerciasis and lymphatic filariasis. Here we demonstrate the use of a biodegradable polyanhydride nanoparticle-based platform for the co-delivery of the antibiotic doxycycline with the antiparasitic drug, ivermectin, to reduce microfilarial burden and rapidly kill adult worms. When doxycycline and ivermectin were co-delivered within polyanhydride nanoparticles, effective killing of adult female Brugia malayi filarial worms was achieved with approximately 4,000-fold reduction in the amount of drug used. Additionally the time to death of the macrofilaria was also significantly reduced (five-fold) when the anti-filarial drug cocktail was delivered within polyanhydride nanoparticles. We hypothesize that the mechanism behind this dramatically enhanced killing of the macrofilaria is the ability of the polyanhydride nanoparticles to behave as a Trojan horse and penetrate the cuticle, bypassing excretory pumps of B. malayi, and effectively deliver drug directly to both the worm and Wolbachia at high enough microenvironmental concentrations to cause death. These provocative findings may have significant consequences for the reduction in the amount of drug and the length of treatment required for filarial infections in terms of patient compliance and reduced cost of treatment. PMID:26496201

  9. Lymphangiosarcoma after filarial infection

    SciTech Connect

    Sordillo, E.M.; Sordillo, P.P.; Hajdu, S.I.; Good, R.A.

    1981-03-01

    A case of lymphangiosarcoma of a lower extremity is described in a patient with chronic lymphedema of that leg from a filarial infection in childhood. Histologically, the neoplasm resembled lymphangiosarcomas that arise in arms that become lymphedematous after mastectomies, but was different in that it also contained areas of calcification consistent with prior filarial infection. Calcifications were also present in muscle uninvolved by the lymphangiosarcoma of this case. The prolonged survival of this patient is unlike that of most patients with lymphangiosarcoma, which is generally shorter. Although lymphedema after filariasis is common, this is the first case of a lymphangiosarcoma arising in chronic lymphedema of filarial origin.

  10. Pan-phylum Comparison of Nematode Metabolic Potential

    PubMed Central

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

    2015-01-01

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

  11. Pan-phylum Comparison of Nematode Metabolic Potential.

    PubMed

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

    2015-05-01

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

  12. Wolbachia endosymbiont of Brugia malayi elicits a T helper type 17-mediated pro-inflammatory immune response through Wolbachia surface protein.

    PubMed

    Pathak, Manisha; Verma, Meenakshi; Srivastava, Mrigank; Misra-Bhattacharya, Shailja

    2015-02-01

    Wolbachia is an endosymbiotic bacterium of the filarial nematode Brugia malayi. The symbiotic relationship between Wolbachia and its filarial host is dependent on interactions between the proteins of both organisms. However, little is known about Wolbachia proteins that are involved in the inflammatory pathology of the host during lymphatic filariasis. In the present study, we cloned, expressed and purified Wolbachia surface protein (r-wsp) from Wolbachia and administered it to mice, either alone or in combination with infective larvae of B. malayi (Bm-L3) and monitored the developing immune response in infected animals. Our results show that spleens and mesenteric lymph nodes of mice immunized with either r-wsp or infected with Bm-L3 show increased percentages of CD4(+) T helper type 17 (Th17) cells and Th1 cytokines like interferon-γ and interleukin-2 (IL-2) along with decreased percentages of regulatory T cells, Th2 cytokines like IL-4 and IL-10 and transforming growth factor β (TGF-β) levels in culture supernatants of splenocytes. These observations were stronger in mice immunized with r-wsp alone. Interestingly, when mice were first immunized with r-wsp and subsequently infected with Bm-L3, percentages of CD4(+) Th17 cells and Th1 cytokines increased even further while that of regulatory T cells, Th2 cytokines and TGF-β levels decreased. These results for the first time show that r-wsp acts synergistically with Bm-L3 in promoting a pro-inflammatory response by increasing Th17 cells and at the same time diminishes host immunological tolerance by decreasing regulatory T cells and TGF-β secretion. © 2014 John Wiley & Sons Ltd.

  13. Responses of Mastomys coucha, that have been infected with Brugia malayi and treated with diethylcarbamazine or albendazole, to re-exposure to infection.

    PubMed

    Khan, M A; Gaur, R L; Dixit, S; Saleemuddin, M; Murthy, P K

    2004-12-01

    The responses of Mastomys coucha to re-exposure to infection with homologous infective larvae (L(3)) of Brugia malayi were investigated, after initial infections with the nematode had been treated subcutaneously for 5 days with diethylcarbamazine (DEC; 150 mg citrate/kg. day) or albendazole (ALB; 50 mg/kg. day). The parasite burdens, serum concentrations of IgG reacting with a soluble somatic extract of adult B. malayi (BmAS), and cytokine and lymphocyte-proliferative responses to filarial antigen (BmAS) or mitogen (concanavilin A or lipopolysaccharide) were studied. The results demonstrated, for the first time, that re-infection with L(3) was only successful in the DEC-treated animals, not the ALB-treated ones. When the ALB-treated animals were re-exposed, interferon-gamma production decreased, lymphocyte-proliferative responses either remained the same (with concanavilin A) or decreased (with BmAS), and concentrations of specific IgG decreased. When the DEC-treated animals were re-exposed, microfilaraemias re-appeared and, although production of interferon-gamma decreased, there were no detectable lymphocyte proliferative responses, and concentrations of specific IgG remained unchanged. Taken together, the results indicate that, at least in the M. coucha model of human filariasis, ALB but not DEC treatment may help to prevent the development of re-infections.

  14. Nematode asparaginyl-tRNA synthetase resolves intestinal inflammation in mice with T-cell transfer colitis.

    PubMed

    Kron, Michael A; Metwali, Ahmed; Vodanovic-Jankovic, Sanja; Elliott, David

    2013-02-01

    The therapeutic effects of a controlled parasitic nematode infection on the course of inflammatory bowel disease (IBD) have been demonstrated in both animal and human models. However, the inability of individual well-characterized nematode proteins to recreate these beneficial effects has limited the application of component immunotherapy to human disease. The nematodes that cause chronic human lymphatic filariasis, Brugia malayi and Wuchereria bancrofti, are among the parasites that induce immune suppression. Filarial lymphatic pathology has been shown to involve NF-κB pathway-dependent production of vascular endothelial growth factor (VEGF), and stimulation of VEGF expression has also been reported by interleukin 8 (IL-8) via NF-κB pathways. Previously, we have shown that the filarial asparaginyl-tRNA synthetase (rBmAsnRS) interacts with IL-8 receptors using a combination of extracellular loops that differ from those bound by IL-8. To test the hypothesis that rBmAsnRS might induce an anti-inflammatory effect in vivo, we studied the effects of rBmAsnRS in an established murine colitis model using T-cell transfer mice. T-cell transfer colitis mice treated intraperitoneally with 100 μg of rBmAsnRS four times over 2 weeks showed resolution of cellular infiltration in the colonic mucosa, along with induction of a CD8(+) cellular response. In addition, rBmAsnRS induced a rise in IL-10 production from CD3(+) and lipopolysaccharide (LPS)- and cytosine phosphate guanosine (CPG)-stimulated splenic cells. In summary, this work demonstrates a novel anti-inflammatory nematode protein, supports the hygiene hypothesis, and supports continued refinement of alternative immunotherapies for treatment of IBD.

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

    PubMed

    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.

  16. Filarial parasites develop faster and reproduce earlier in response to host immune effectors that determine filarial life expectancy.

    PubMed

    Babayan, Simon A; Read, Andrew F; Lawrence, Rachel A; Bain, Odile; Allen, Judith E

    2010-10-19

    Humans and other mammals mount vigorous immune assaults against helminth parasites, yet there are intriguing reports that the immune response can enhance rather than impair parasite development. It has been hypothesized that helminths, like many free-living organisms, should optimize their development and reproduction in response to cues predicting future life expectancy. However, immune-dependent development by helminth parasites has so far eluded such evolutionary explanation. By manipulating various arms of the immune response of experimental hosts, we show that filarial nematodes, the parasites responsible for debilitating diseases in humans like river blindness and elephantiasis, accelerate their development in response to the IL-5 driven eosinophilia they encounter when infecting a host. Consequently they produce microfilariae, their transmission stages, earlier and in greater numbers. Eosinophilia is a primary host determinant of filarial life expectancy, operating both at larval and at late adult stages in anatomically and temporally separate locations, and is implicated in vaccine-mediated protection. Filarial nematodes are therefore able to adjust their reproductive schedules in response to an environmental predictor of their probability of survival, as proposed by evolutionary theory, thereby mitigating the effects of the immune attack to which helminths are most susceptible. Enhancing protective immunity against filarial nematodes, for example through vaccination, may be less effective at reducing transmission than would be expected and may, at worst, lead to increased transmission and, hence, pathology.

  17. Yeast-Based High-Throughput Screens to Identify Novel Compounds Active against Brugia malayi

    PubMed Central

    Bilsland, Elizabeth; Bean, Daniel M.; Devaney, Eileen; Oliver, Stephen G.

    2016-01-01

    Background Lymphatic filariasis is caused by the parasitic worms Wuchereria bancrofti, Brugia malayi or B. timori, which are transmitted via the bites from infected mosquitoes. Once in the human body, the parasites develop into adult worms in the lymphatic vessels, causing severe damage and swelling of the affected tissues. According to the World Health Organization, over 1.2 billion people in 58 countries are at risk of contracting lymphatic filariasis. Very few drugs are available to treat patients infected with these parasites, and these have low efficacy against the adult stages of the worms, which can live for 7–15 years in the human body. The requirement for annual treatment increases the risk of drug-resistant worms emerging, making it imperative to develop new drugs against these devastating diseases. Methodology/Principal Findings We have developed a yeast-based, high-throughput screening system whereby essential yeast genes are replaced with their filarial or human counterparts. These strains are labeled with different fluorescent proteins to allow the simultaneous monitoring of strains with parasite or human genes in competition, and hence the identification of compounds that inhibit the parasite target without affecting its human ortholog. We constructed yeast strains expressing eight different Brugia malayi drug targets (as well as seven of their human counterparts), and performed medium-throughput drug screens for compounds that specifically inhibit the parasite enzymes. Using the Malaria Box collection (400 compounds), we identified nine filarial specific inhibitors and confirmed the antifilarial activity of five of these using in vitro assays against Brugia pahangi. Conclusions/Significance We were able to functionally complement yeast deletions with eight different Brugia malayi enzymes that represent potential drug targets. We demonstrated that our yeast-based screening platform is efficient in identifying compounds that can discriminate between

  18. Filarial infection influences mosquito behaviour and fecundity

    PubMed Central

    Gleave, Katherine; Cook, Darren; Taylor, Mark J.; Reimer, Lisa J.

    2016-01-01

    Understanding vector-parasite interactions is increasingly important as we move towards the endpoint goals set by the Global Programme for the Elimination of Lymphatic Filariasis (GPELF), as interaction dynamics may change with reduced transmission pressure. Elimination models used to predict programmatic endpoints include parameters for vector-specific transmission dynamics, despite the fact that our knowledge of the host-seeking behaviour of filariasis infected mosquitoes is lacking. We observed a dynamic, stage-specific and density dependent change in Aedes aegypti behaviour towards host cues when exposed to Brugia malayi filarial parasites. Infected mosquitoes exhibited reduced activation and flight towards a host during the period of larval development (L1/L2), transitioning to a 5 fold increase in activation and flight towards a host when infective stage larvae (L3) were present (p < 0.001). In uninfected control mosquitoes, we observed a reduction in convergence towards a host during the same period. Furthermore, this behaviour was density dependent with non-activated mosquitoes harbouring a greater burden of L1 and L2 larvae while activated mosquitoes harboured a greater number of L3 (p < 0.001). Reductions in fecundity were also density-dependent, and extended to mosquitoes that were exposed to microfilariae but did not support larval development. PMID:27796352

  19. Prevalence of filarial parasites in domestic and stray cats in Selangor State, Malaysia.

    PubMed

    Al-Abd, Nazeh M; Nor, Zurainee Mohamed; Kassim, Mustafa; Mansor, Marzida; Al-Adhroey, Abdulelah H; Ngui, Romano; Sivanandam, Sinnadurai

    2015-09-01

    To determine the prevalence of the filarial parasites,ie.,Brugia malayi, Brugia, Brugia pahangi(B. pahangi), Dirofilaria immitisandDirofilaria repens (D. repens) in domestic and stray cats. A total of 170 blood sample were collected from domestic and stray cats and examined for filarial worm parasites in two localities, Pulau Carey and Bukit Gasing, Selangor State, Malaysia. The overall prevalence of infection was 23.5% (40/170; 95% CI = 17.4-30.6). Of this, 35% (14/40; 95% CI = 22.1-50.5) and 50% (20/40; 95% CI = 35.2-64.8) were positive for single B. pahangi nd D. repens, respectively. The remaining of 15% (6/40; 95% CI = 7.1-29.1) were positive for mixed B. pahangi and D. repens. In addition, 75% of the infected cats were domestic, and 25% were strays. No Brugia malayi and Dirofilaria immitis was detected. Eighty-four cats were captured at Pulau Carey, of which 35.7% (30/84) were infected. Among the cats determined to be infected, 93% (28/30; 95% CI = 78.7-98.2) were domestic, and only 6.7% (2/30; 95% CI = 19.0-21.3) were strays. Conversely, the number of infected cats was three times lower in Bukit Gasing than in Pulau Carey, and most of the cats were stray. B. pahangi and D. repens could be the major parasites underlying filariasis in the study area. Adequate prophylactic plans should be administrated in the cat population in study area. Copyright © 2015 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

  20. Absence of Wolbachia endobacteria in the human parasitic nematode Dracunculus medinensis and two related Dracunculus species infecting wildlife

    PubMed Central

    2014-01-01

    Background Wolbachia endosymbionts are a proven target for control of human disease caused by filarial nematodes. However, little is known about the occurrence of Wolbachia in taxa closely related to the superfamily Filarioidea. Our study addressed the status of Wolbachia presence in members of the superfamily Dracunculoidea by screening the human parasite Dracunculus medinensis and related species from wildlife for Wolbachia. Findings D. medinensis, D. lutrae and D. insignis specimens were all negative for Wolbachia colonization by PCR screening for the Wolbachia ftsZ, 16S rRNA and Wolbachia surface protein (wsp) sequences. The quality and purity of the DNA preparations was confirmed by amplification of nematode 18S rRNA and cytochrome c oxidase subunit I sequences. Furthermore, Wolbachia endobacteria were not detected by whole mount fluorescence staining, or by immunohistochemistry using a Wolbachia-specific antiserum. In contrast, positive control Brugia malayi worms were shown to harbour Wolbachia by PCR, fluorescence staining and immunohistochemistry. Conclusions Three examined species of Dracunculus showed no evidence of Wolbachia endobacteria. This supports that members of the superfamily Dracunculoidea are free of Wolbachia. Within the order Spirurida, these endosymbionts appear restricted to the Filarioidea. PMID:24685011

  1. Imported Infections with Mansonella perstans Nematodes, Italy

    PubMed Central

    Beltrame, Anna; Buonfrate, Dora; Staffolani, Silvia; Degani, Monica; Gobbo, Maria; Angheben, Andrea; Marocco, Stefania; Bisoffi, Zeno

    2017-01-01

    We report 74 patients in Italy infected with Mansonella perstans nematodes, a poorly described filarial parasite. M. perstans nematodes should be included in the differential diagnosis for patients with eosinophilia from disease-endemic countries. Serologic analysis is useful for screening, and testing for microfilaremia in peripheral blood should be performed for parasite-positive patients. PMID:28820369

  2. Removing the needle from the haystack: Enrichment of Wolbachia endosymbiont transcripts from host nematode RNA by Cappable-seq™

    PubMed Central

    Luck, Ashley N.; Slatko, Barton E.; Foster, Jeremy M.

    2017-01-01

    Efficient transcriptomic sequencing of microbial mRNA derived from host-microbe associations is often compromised by the much lower relative abundance of microbial RNA in the mixed total RNA sample. One solution to this problem is to perform extensive sequencing until an acceptable level of transcriptome coverage is obtained. More cost-effective methods include use of prokaryotic and/or eukaryotic rRNA depletion strategies, sometimes in conjunction with depletion of polyadenylated eukaryotic mRNA. Here, we report use of Cappable-seq™ to specifically enrich, in a single step, Wolbachia endobacterial mRNA transcripts from total RNA prepared from the parasitic filarial nematode, Brugia malayi. The obligate Wolbachia endosymbiont is a proven drug target for many human filarial infections, yet the precise nature of its symbiosis with the nematode host is poorly understood. Insightful analysis of the expression levels of Wolbachia genes predicted to underpin the mutualistic association and of known drug target genes at different life cycle stages or in response to drug treatments is typically challenged by low transcriptomic coverage. Cappable-seq resulted in up to ~ 5-fold increase in the number of reads mapping to Wolbachia. On average, coverage of Wolbachia transcripts from B. malayi microfilariae was enriched ~40-fold by Cappable-seq. Additionally, this method has an additional benefit of selectively removing abundant prokaryotic ribosomal RNAs.The deeper microbial transcriptome sequencing afforded by Cappable-seq facilitates more detailed characterization of gene expression levels of pathogens and symbionts present in animal tissues. PMID:28291780

  3. Exome and Transcriptome Sequencing of Aedes aegypti Identifies a Locus That Confers Resistance to Brugia malayi and Alters the Immune Response

    PubMed Central

    Juneja, Punita; Ariani, Cristina V.; Ho, Yung Shwen; Akorli, Jewelna; Palmer, William J.; Pain, Arnab; Jiggins, Francis M.

    2015-01-01

    Many mosquito species are naturally polymorphic for their abilities to transmit parasites, a feature which is of great interest for controlling vector-borne disease. Aedes aegypti, the primary vector of dengue and yellow fever and a laboratory model for studying lymphatic filariasis, is genetically variable for its capacity to harbor the filarial nematode Brugia malayi. The genome of Ae. aegypti is large and repetitive, making genome resequencing difficult and expensive. We designed exome captures to target protein-coding regions of the genome, and used association mapping in a wild Kenyan population to identify a single, dominant, sex-linked locus underlying resistance. This falls in a region of the genome where a resistance locus was previously mapped in a line established in 1936, suggesting that this polymorphism has been maintained in the wild for the at least 80 years. We then crossed resistant and susceptible mosquitoes to place both alleles of the gene into a common genetic background, and used RNA-seq to measure the effect of this locus on gene expression. We found evidence for Toll, IMD, and JAK-STAT pathway activity in response to early stages of B. malayi infection when the parasites are beginning to die in the resistant genotype. We also found that resistant mosquitoes express anti-microbial peptides at the time of parasite-killing, and that this expression is suppressed in susceptible mosquitoes. Together, we have found that a single resistance locus leads to a higher immune response in resistant mosquitoes, and we identify genes in this region that may be responsible for this trait. PMID:25815506

  4. Exome and transcriptome sequencing of Aedes aegypti identifies a locus that confers resistance to Brugia malayi and alters the immune response.

    PubMed

    Juneja, Punita; Ariani, Cristina V; Ho, Yung Shwen; Akorli, Jewelna; Palmer, William J; Pain, Arnab; Jiggins, Francis M

    2015-03-01

    Many mosquito species are naturally polymorphic for their abilities to transmit parasites, a feature which is of great interest for controlling vector-borne disease. Aedes aegypti, the primary vector of dengue and yellow fever and a laboratory model for studying lymphatic filariasis, is genetically variable for its capacity to harbor the filarial nematode Brugia malayi. The genome of Ae. aegypti is large and repetitive, making genome resequencing difficult and expensive. We designed exome captures to target protein-coding regions of the genome, and used association mapping in a wild Kenyan population to identify a single, dominant, sex-linked locus underlying resistance. This falls in a region of the genome where a resistance locus was previously mapped in a line established in 1936, suggesting that this polymorphism has been maintained in the wild for the at least 80 years. We then crossed resistant and susceptible mosquitoes to place both alleles of the gene into a common genetic background, and used RNA-seq to measure the effect of this locus on gene expression. We found evidence for Toll, IMD, and JAK-STAT pathway activity in response to early stages of B. malayi infection when the parasites are beginning to die in the resistant genotype. We also found that resistant mosquitoes express anti-microbial peptides at the time of parasite-killing, and that this expression is suppressed in susceptible mosquitoes. Together, we have found that a single resistance locus leads to a higher immune response in resistant mosquitoes, and we identify genes in this region that may be responsible for this trait.

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

    PubMed

    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.

  6. The complete mitochondrial genome of Setaria digitata (Nematoda: Filarioidea): Mitochondrial gene content, arrangement and composition compared with other nematodes.

    PubMed

    Yatawara, Lalani; Wickramasinghe, Susiji; Rajapakse, R P V J; Agatsuma, Takeshi

    2010-09-01

    In the present study, we determined the complete mitochondrial (mt) genome sequence (13,839bp) of parasitic nematode Setaria digitata and its structure and organization compared with Onchocerca volvulus, Dirofilaria immitis and Brugia malayi. The mt genome of S. digitata is slightly larger than the mt genomes of other filarial nematodes. S. digitata mt genome contains 36 genes (12 protein-coding genes, 22 transfer RNAs and 2 ribosomal RNAs) that are typically found in metazoans. This genome contains a high A+T (75.1%) content and low G+C content (24.9%). The mt gene order for S. digitata is the same as those for O. volvulus, D. immitis and B. malayi but it is distinctly different from other nematodes compared. The start codons inferred in the mt genome of S. digitata are TTT, ATT, TTG, ATG, GTT and ATA. Interestingly, the initiation codon TTT is unique to S. digitata mt genome and four protein-coding genes use this codon as a translation initiation codon. Five protein-coding genes use TAG as a stop codon whereas three genes use TAA and four genes use T as a termination codon. Out of 64 possible codons, only 57 are used for mitochondrial protein-coding genes of S. digitata. T-rich codons such as TTT (18.9%), GTT (7.9%), TTG (7.8%), TAT (7%), ATT (5.7%), TCT (4.8%) and TTA (4.1%) are used more frequently. This pattern of codon usage reflects the strong bias for T in the mt genome of S. digitata. In conclusion, the present investigation provides new molecular data for future studies of the comparative mitochondrial genomics and systematic of parasitic nematodes of socio-economic importance. 2010 Elsevier B.V. All rights reserved.

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

    PubMed

    Cadman, Emma T; Thysse, Katherine A; Bearder, Siobhan; Cheung, Anita Y N; Johnston, Ashleigh C; Lee, James J; Lawrence, Rachel A

    2014-03-01

    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.

  8. Brugia malayi Antigen (BmA) Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells

    PubMed Central

    Mouser, Emily E. I. M.; Pollakis, Georgios; Yazdanbakhsh, Maria; Harnett, William

    2016-01-01

    One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA) and excretory-secretory product 62 (ES-62) from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th) cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs. PMID:26808476

  9. Inhibition of the activation of Hageman factor (factor XII) and of platelet aggregation by extracts of Brugia malayi microfilariae.

    PubMed

    Foster, C B; Flanigan, T P; Kazura, J W; Dumenco, L L; Ratnoff, O D

    1991-05-01

    In human filariasis, large numbers of blood-borne microfilariae circulate unimpeded through the blood stream. How intravascular filarial parasites avoid precipitating thrombosis has not been studied in detail. We hypothesized that extracts of Brugia malayi microfilariae would contain factors that inhibit activation of hemostatic mechanisms. Initial studies demonstrated an inhibitor specific for the intrinsic coagulation cascade. The addition of microfilarial extracts to human plasma prolonged the activated partial thromboplastin time in a dose-dependent fashion but did not prolong the prothrombin, thrombin, or Russell's viper venom times. Microfilarial extracts (0.1 mg/ml) completely inhibited activation of Hageman factor (factor XII, at 0.05 U/ml) as measured in an amidolytic assay. Hageman factor previously activated by ellagic acid (factor XIIa) retained full enzymatic activity in the presence of microfilarial extract (0.1 mg/ml). The presence of inhibitory activity in the culture medium of live parasites raises the possibility that microfilariae secrete an inhibitory protein into their local environment. Microfilarial extracts at a final concentration of 0.1 mg/ml also inhibited collagen- and adenosine diphosphate-induced platelet aggregation. Arachidonic acid-induced platelet aggregation was inhibited by microfilarial extracts at a final concentration of 0.6 mg/ml. These results suggest that microfilariae of Brugia malayi, a human filarial parasite, may avoid initiating thrombosis through inhibition of the intrinsic coagulation pathway and platelet aggregation.

  10. Identification of a highly immunoreactive epitope of Brugia malayi TPx recognized by the endemic sera.

    PubMed

    Madhumathi, Jayaprakasam; Prince, Prabhu Rajaiah; Gayatri, Subash Chellam; Aparnaa, Ramanathan; Kaliraj, Perumal

    2010-12-01

    Filarial thiordoxin peroxidase is a major antioxidant that plays a crucial role in parasite survival. Although Brugia malayi TPx has been shown to be a potential vaccine candidate, it shares 63% homology with its mammalian counterpart, limiting its use as a vaccine or drug target. In silico analysis of TPx sequence revealed a linear B epitope in the host's nonhomologous region. The peptide sequence (TPx peptide(27-48)) was synthesized, and its reactivity with clinical sera from an endemic region was analyzed. The peptide showed significantly high reactivity (P < 0.05) against the sera of putatively immune individuals compared to the nonendemic control sera. It also showed high reactivity against the sera of patients with chronic pathology and patent infection. The high reactivity of the peptide with endemic immune sera equivalent to that of whole protein shows that it forms a dominant B epitope of TPx protein and thus could be utilized for incorporation into a multiepitope vaccine construct for filariasis.

  11. Brugia malayi Asparaginyl - tRNA Synthetase Stimulates Endothelial Cell Proliferation, Vasodilation and Angiogenesis

    PubMed Central

    D, Jeeva Jothi; Dhanraj, Muthu; Solaiappan, Shanmugam; Sivanesan, Sanjana; Kron, Michael; Dhanasekaran, Anuradha

    2016-01-01

    A hallmark of chronic infection with lymphatic filarial parasites is the development of lymphatic disease which often results in permanent vasodilation and lymphedema, but all of the mechanisms by which filarial parasites induce pathology are not known. Prior work showed that the asparaginyl-tRNA synthetase (BmAsnRS) of Brugia malayi, an etiological agent of lymphatic filariasis, acts as a physiocrine that binds specifically to interleukin-8 (IL-8) chemokine receptors. Endothelial cells are one of the many cell types that express IL-8 receptors. IL-8 also has been reported previously to induce angiogenesis and vasodilation, however, the effect of BmAsnRS on endothelial cells has not been reported. Therefore, we tested the hypothesis that BmAsnRS might produce physiological changes in endothelial by studying the in vitro effects of BmAsnRS using a human umbilical vein cell line EA.hy926 and six different endothelial cell assays. Our results demonstrated that BmAsnRS produces consistent and statistically significant effects on endothelial cells that are identical to the effects of VEGF, vascular endothelial growth factor. This study supports the idea that new drugs or immunotherapies that counteract the adverse effects of parasite-derived physiocrines may prevent or ameliorate the vascular pathology observed in patients with lymphatic filariasis. PMID:26751209

  12. Zoonotic Brugia pahangi filariasis in a suburbia of Kuala Lumpur City, Malaysia.

    PubMed

    Tan, Lian Huat; Fong, Mun Yik; Mahmud, Rohela; Muslim, Azdayanti; Lau, Yee Ling; Kamarulzaman, Adeeba

    2011-01-01

    Five local Malaysian patients with clinical manifestations consistent with lymphatic filariasis were referred to our medical centre between 2003 and 2006. Although no microfilariae (mf) were detected in their nocturnal blood samples, all were diagnosed to have lymphatic filariasis on the basis of clinical findings and positive serology results. PCR on their blood samples revealed that two of the patients were infected with Brugia pahangi, an animal filarial worm hitherto not known to cause human disease in the natural environment. All the patients were successfully treated with anti-filarial drugs: four patients were treated with a combination of diethylcarbamazine (DEC) and albendazole, and one with doxycycline. Four of them were residents of Petaling Jaya, a residential suburbia located 10 km southwest of Kuala Lumpur city, Malaysia. The fifth patient was a frequent visitor of the suburbia. This suburbia has no history or record of B. malayi infection. The most likely vector of the worm was Armigeres subalbatus as extensive entomological surveys within the suburbia revealed only adult females of this mosquito species were infected with B. pahangi larvae. Wild monkeys caught in the suburbia were free from B. pahangi mf, but domestic cats were mf positive. This suggests that infected cats might be the source of the zoonotic infection in the suburbia. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  13. Brugia malayi soluble and excretory-secretory proteins attenuate development of streptozotocin-induced type 1 diabetes in mice.

    PubMed

    Amdare, N; Khatri, V; Yadav, R S P; Tarnekar, A; Goswami, K; Reddy, M V R

    2015-12-01

    Understanding the modulation of the host-immune system by pathogens-like filarial parasites offers an alternate approach to prevent autoimmune diseases. In this study, we have shown that treatment with filarial proteins prior to or after the clinical onset of streptozotocin-induced type-1 diabetes (T1D) can ameliorate the severity of disease in BALB/c mice. Pre-treatment with Brugia malayi adult soluble (Bm A S) or microfilarial excretory-secretory (Bm mf ES) or microfilarial soluble (Bm mf S) antigens followed by induction of diabetes led to lowering of fasting blood glucose levels with as many as 57.5-62.5% of mice remaining nondiabetic. These proteins were more effective when they were used to treat the mice with established T1D as 62.5-71.5% of the mice turned to be nondiabetic. Histopathological examination of pancreas of treated mice showed minor inflammatory changes in pancreatic islet cell architecture. The therapeutic effect was found to be associated with the decreased production of cytokines TNF-α & IFN-γ and increased production of IL-10 in the culture supernatants of splenocytes of treated mice. A switch in the production of anti-insulin antibodies from IgG2a to IgG1 isotype was also seen. Together these results provide a proof towards utilizing the filarial derived proteins as novel anti-diabetic therapeutics.

  14. Filarial hydropneumothorax: a strange journey.

    PubMed

    Chakraborty, Arkaprabha; Mukherjee, Anindya; Talukdar, Payel; Talukdar, Arunansu

    2015-11-24

    Filarial infection can have varied manifestations, but hydropneumothorax at presentation has not yet been reported. A 28-year-old man presented to our hospital with heaviness of the left chest for the past 10 days, which was preceded by a sudden, short stabbing pain in the left chest after straining. Chest X-ray revealed left-sided hydropneumothorax. A peripheral blood picture revealed significant eosinophilia. A pleural fluid report also showed eosinophilia and a few motile microfilaria of Wuchereria bancrofti. Microfilaria was also documented in peripheral blood. There was no evidence of other organ system involvement. The patient was diagnosed with 'Filarial Hydropneumothorax'. After treatment with a temporary chest drain and oral diethylcarbamazine citrate, there was dramatic relief of symptoms and radiological improvement. The patient has been symptom free with no features of recurrence through 8 months of follow-up. 2015 BMJ Publishing Group Ltd.

  15. Detection of enzymes dehydrogenases and proteases inBrugia malayi filarial parasites.

    PubMed

    Bhandary, Y P; Krithika, K N; Kulkarni, Sandeep; Reddy, M V R; Harinath, B C

    2006-03-01

    Lymphatic filariasis caused mainly by infection fromW. bancrofti andB. malayi remains a major cause of clinical morbidity in tropical and subtropical countries. Analysis ofB. malayi mf, infective larval and adult worm lysates for the activity of enzymes led to the demonstration of activities of three key enzymes of carbohydrate metabolism viz., Malate dehydrogenase (MDH), Malic enzyme (ME) and Glucose-6-phosphate dehydrogenase (G6PDH) in all the three stages of the parasite. The specific activity of all the three dehydrogenases was significantly high in mf lysate compared to their activity in lysates of the other two stages (P<0.001). Analysis by native polyacrylamide gel to their activity inlysates of the other two stages (P<0.001). Analysis by native polyacrylamide gel electrophoresis (PAGE) using 7.5% non-gradient gel showed the presence of two isoforms of each of the three enzymes (MDH, ME & G6PDH) in mf lysate, while only one form of each enzyme was present in L(3) larval and adult worm lysates. Further proteolytic enzyme activity was demonstrated both in microfilarial and infective larval lysates ofB. malayi. While both mf and L(3) larval lysates showed optimal protease activity at alkaline pH of 9.0, the mf lysate showed increased activity also at pH 3.0. The infective larval lysate was markedly inhibited by Tosylamide-L-Phenylalanine chloromethyl ketone (TPCK), a thiol protease inhibitor, while the protease activity in mf lysate was significantly inhibited by both TPCK and a serine protease inhibitor Phenyl Methyl Sulphonyl Flouride (PMSF). In sodium do-decyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), using gelatin copolymerized gel, the microfilarial lysate showed 3 protease molecules of 40 kDa, 180 kDa and 200 kDa and the L(3) larval lysate had 6 protease molecules of 18, 25, 37, 49, 70 and 200 kDa size.

  16. Immunopathogenesis of lymphatic filarial disease.

    PubMed

    Babu, Subash; Nutman, Thomas B

    2012-11-01

    Although two thirds of the 120 million people infected with lymph-dwelling filarial parasites have subclinical infections, ~40 million have lymphedema and/or other pathologic manifestations including hydroceles (and other forms of urogenital disease), episodic adenolymphangitis, tropical pulmonary eosinophilia, lymphedema, and (in its most severe form) elephantiasis. Adult filarial worms reside in the lymphatics and lymph nodes and induce changes that result in dilatation of lymphatics and thickening of the lymphatic vessel walls. Progressive lymphatic damage and pathology results from the summation of the effect of tissue alterations induced by both living and nonliving adult parasites, the host inflammatory response to the parasites and their secreted antigens, the host inflammatory response to the endosymbiont Wolbachia, and those seen as a consequence of secondary bacterial or fungal infections. Inflammatory damage induced by filarial parasites appears to be multifactorial, with endogenous parasite products, Wolbachia, and host immunity all playing important roles. This review will initially examine the prototypical immune responses engendered by the parasite and delineate the regulatory mechanisms elicited to prevent immune-mediated pathology. This will be followed by a discussion of the proposed mechanisms underlying pathogenesis, with the central theme being that pathogenesis is a two-step process-the first initiated by the parasite and host innate immune system and the second propagated mainly by the host's adaptive immune system and by other factors (including secondary infections).

  17. Characterization of a beta-tubulin gene and a beta-tubulin gene products of Brugia pahangi.

    PubMed

    Guénette, S; Prichard, R K; Klein, R D; Matlashewski, G

    1991-02-01

    A genomic clone containing a beta-tubulin gene from the parasitic nematode Brugia pahangi was isolated. This gene was sequenced to determine its size, structural organization, and corresponding primary amino acid sequence. The coding sequence of the beta-tubulin gene spans 3.8 kb, is organized into 9 exons and expresses an mNRA of 1.8 kb which codes for a protein of 448 amino acids. The predicted beta-tubulin amino acid sequence is 89%, 94%, 90% and 88% identical to the chicken beta 2, and the Caenorhabditis elegans ben-1, tub-1 and mec-7 gene products, respectively. Southern hybridization analyses demonstrated that there is only one copy of this gene isotype but that other distinct beta-tubulin genes may exist in the Brugia pahangi genome. A nematode specific antipeptide rabbit antiserum raised against the predicted amino acid sequence of the extreme carboxy-terminal region of the B. pahangi beta-tubulin was used to identify beta-tubulin isoforms in adult nematodes and microfilariae. Isoforms detected by this nematode-specific antipeptide antiserum were identical in both adult worms and microfilariae and did not differ from the isoform patterns detected by a monoclonal antibody recognizing a conserved beta-tubulin epitope. This suggests that this carboxy-terminal peptide is highly represented in the beta-tubulin isoforms of B. pahangi.

  18. Molecular phylogenetic studies on filarial parasites based on 5S ribosomal spacer sequences.

    PubMed

    Xie, H; Bain, O; Williams, S A

    1994-06-01

    This paper is the first large-scale molecular phylogenetic study on filarial parasites (family Onchocercidae) which includes 16 species of 6 genera: Brugia beaveri Ash et Little, 1962, B. buckleyi Dissanaike et Paramananthan, 1961; B. malayi (Brug, 1927) Buckley, 1960; B. pahangi (Buckley et Edeson, 1956) Buckley, 1960; B. patei (Buckley, Nelson et Heisch, 1958) Buckley, 1960; B. timori Partono et al, 1977; Wuchereria bancrofti (Cobbold, 1877) Seurat, 1921: W. kalimantani Palmieri. Purnomo, Dennis and Marwoto, 1980: Mansonella perstans (Manson, 1891) Eberhard et Orihel, 1984; loa loc, Stiles, 1905; Onchocerca volvulus (Leuckart, 1983) Railliet er Henry, 1910; O. ochengi Bwangamoi, 1969; O. gutturosa Neumann, 1910; Dirofilaria immitis (Leidy, 1856) Railliet e Henry, 1911; Acanthocheilonema viteae (Krepkogorskaya, 1933) Bain, Baker et Chabaud, 1982 and Litomosoides sigmodontis Chandler, 1931. 5S rRNA gene spacer region sequence data were collected by PCR, cloning and dideoxy sequencing. The 5S rRNA gene spacer region sequences were aligned and analyzed by maximum parsimony algorithms, distance methods and maximum likelihood methods to construct phylogenetic trees. Bootstrap analysis was used to test the robustness of the different phylogenetic reconstructions. The data indicated that 5S spacer region sequences are highly conserved within species yet differ significantly between species. Spliced leader sequences were observed in all of the 5S rDNA spacers with no sequence variation, although flanking region sequence and length heterogeneity was observed even within species. All of the various tree-building methods gave very similar results. This study identified four clades which are strongly supported by bootstrap analysis the Brugia clade; the Wuchereria clade; the Brugia-Wuchereria clade and the Onchocerca clade. The analyses indicated that L. sigmodontis and A. viteae may be the most primitive among the 16 species studied. The data did not show any close

  19. Antifilarial drugs, in the doses employed in mass drug administrations by the Global Programme to Eliminate Lymphatic Filariasis, reverse lymphatic pathology in children with Brugia malayi infection.

    PubMed

    Shenoy, R K; Suma, T K; Kumaraswami, V; Rahmah, N; Dhananjayan, G; Padma, S

    2009-04-01

    Lymphatic filariasis is increasingly viewed as the result of an infection that is often acquired in childhood. The lymphatic pathology that occurs in the disease is generally believed to be irreversible. In a recent study in India, Doppler ultrasonography and lymphoscintigraphy were used to explore subclinical pathology in 100 children from an area endemic for Brugia malayi infection. All the children investigated showed some evidence of current or previous filarial infection. Some were microfilaraemic but asymptomatic, some were amicrofilaraemic but had filarial disease or a past history of microfilaraemia and/or filarial disease, and the rest, though amicrofilaraemic, asymptomatic and without any history of microfilaraemia or filarial disease, were seropositive for antifilarial IgG(4) antibodies. All the children were treated every 6 months, with a single combined dose of diethylcarbamazine (6 mg/kg) and albendazole (400 mg), and followed up for 24 months. By the end of this period all but one of the children were amicrofilaraemic and the 'filarial dance sign' could not be detected in any of the 14 children who had initially been found positive for this sign. Although lymphoscintigraphy revealed lymph-node and lymph-vessel damage in 82% of the children at enrolment, in about 67% of the children this pathology was markedly reduced by the 24-month follow-up. These results indicate that the drug regimens used in the mass drug administrations run by the Global Programme to Eliminate Lymphatic Filariasis are capable of reversing subclinical lymphatic damage and can provide benefits other than interruption of transmission in endemic areas. The implications of these findings are presented and discussed.

  20. Molecular systematics of filarial parasites, with an emphasis on groups of medical and veterinary importance, and its relevance for epidemiology.

    PubMed

    Morales-Hojas, Ramiro

    2009-09-01

    Filarial parasites are members of the Phylum Nemata that comprise several species of medical and veterinary importance. Among the human diseases caused by members of this group of nematodes are river blindness and lymphatic filariasis, which afflict millions of people in the tropics. These diseases not only have an impact on the health of the people affected but also bear a great socioeconomic burden. Despite their relevance, the systematics of the filarial parasites is not well understood yet, and additional molecular phylogenetic studies are required to comprehend the evolution of these parasites. Identifying the patterns of evolution of these parasites will be of relevance in preventing emerging zoonoses. The present review examines the information about the molecular systematics of filarial parasites available in the literature and evaluates the relevance of the different directions of future research. Furthermore, it is also intended to highlight the relevance of molecular systematic studies in the molecular epidemiology research area.

  1. Novel retinoid-binding proteins from filarial parasites.

    PubMed Central

    Sani, B P; Vaid, A; Comley, J C; Montgomery, J A

    1985-01-01

    The present study deals with the discovery and partial characterization of specific binding proteins for retinol and retinoic acid from filarial parasites (worms of the superfamily Filarioidea), including those from two species of Onchocerca. These binding proteins, which are distinct in their physicochemical properties and in the mode of ligand interactions from the host-tissue retinoid-binding proteins, may be involved in the mediation of the putative biological roles of retinoids in the control of parasitic growth, differentiation and reproduction. Parasite retinol-binding protein and retinoic acid-binding protein exhibited specificity for binding retinol and retinoic acid respectively. Both the binding proteins showed an s20,w value of 2.0 S. On gel filtration, both proteins were retarded to a position corresponding to the same molecular size (19.0 kDa). On preparative columns, the parasite binding proteins exhibited isoelectric points at pH 5.7 and 5.75. Unlike the retinoid-binding proteins of mammalian and avian origin, the parasite retinoid-binding proteins showed a lack of mercurial sensitivity in ligand binding. The comparative amounts of retinoic acid-binding protein in five parasites, Onchocerca volvulus, Onchocerca gibsoni, Dipetalonema viteae, Brugia pahangi and Dirofilaria immitis, were between 2.7 and 3.1 pmol of retinoic acid bound/mg of extractable protein. However, the levels of parasite retinol-binding protein were between 4.8 and 5.8 pmol/mg, which is considerably higher than the corresponding levels of cellular retinol-binding protein of mammalian and avian origin. Both retinol- and retinoic acid-binding-protein levels in O. volvulus-infected human nodules and O. gibsoni-infected bovine nodules were similar to their levels in mammalian tissues. Also, these nodular binding proteins, like the host-binding proteins, exhibited mercurial sensitivity to ligand interactions. PMID:3004410

  2. Absence of the Filarial Endosymbiont Wolbachia in Seal Heartworm (Acanthocheilonema spirocauda) but Evidence of Ancient Lateral Gene Transfer.

    PubMed

    Keroack, Caroline D; Wurster, Jenna I; Decker, Caroline G; Williams, Kalani M; Slatko, Barton E; Foster, Jeremy M; Williams, Steven A

    2016-06-01

    The symbiotic relationship of Wolbachia spp. was first observed in insects and subsequently in many parasitic filarial nematodes. This bacterium is believed to provide metabolic and developmental assistance to filarial parasitic nematodes, although the exact nature of this relationship remains to be fully elucidated. While Wolbachia is present in most filarial nematodes in the family Onchocercidae, it is absent in several disparate species such as the human parasite Loa loa . All tested members of the genus Acanthocheilonema, such as Acanthocheilonema viteae, have been shown to lack Wolbachia. Consistent with this, we show that Wolbachia is absent from the seal heartworm (Acanthocheilonema spirocauda), but lateral gene transfer (LGT) of DNA sequences between Wolbachia and A. spirocauda has occurred, indicating a past evolutionary association. Seal heartworm is an important pathogen of phocid seals and understanding its basic biology is essential for conservation of the host. The findings presented here may allow for the development of future treatments or diagnostics for the disease and also aid in clarification of the complicated nematode-Wolbachia relationship.

  3. Tissue and Stage-Specific Distribution of Wolbachia in Brugia malayi

    PubMed Central

    Fischer, Kerstin; Beatty, Wandy L.; Jiang, Daojun; Weil, Gary J.; Fischer, Peter U.

    2011-01-01

    Background Most filarial parasite species contain Wolbachia, obligatory bacterial endosymbionts that are crucial for filarial development and reproduction. They are targets for alternative chemotherapy, but their role in the biology of filarial nematodes is not well understood. Light microscopy provides important information on morphology, localization and potential function of these bacteria. Surprisingly, immunohistology and in situ hybridization techniques have not been widely used to monitor Wolbachia distribution during the filarial life cycle. Methods/Principal Findings A monoclonal antibody directed against Wolbachia surface protein and in situ hybridization targeting Wolbachia 16S rRNA were used to monitor Wolbachia during the life cycle of B. malayi. In microfilariae and vector stage larvae only a few cells contain Wolbachia. In contrast, large numbers of Wolbachia were detected in the lateral chords of L4 larvae, but no endobacteria were detected in the genital primordium. In young adult worms (5 weeks p.i.), a massive expansion of Wolbachia was observed in the lateral chords adjacent to ovaries or testis, but no endobacteria were detected in the growth zone of the ovaries, uterus, the growth zone of the testis or the vas deferens. Confocal laser scanning and transmission electron microscopy showed that numerous Wolbachia are aligned towards the developing ovaries and single endobacteria were detected in the germline. In inseminated females (8 weeks p.i.) Wolbachia were observed in the ovaries, embryos and in decreasing numbers in the lateral chords. In young males Wolbachia were found in distinct zones of the testis and in large numbers in the lateral chords in the vicinity of testicular tissue but never in mature spermatids or spermatozoa. Conclusions Immunohistology and in situ hybridization show distinct tissue and stage specific distribution patterns for Wolbachia in B. malayi. Extensive multiplication of Wolbachia occurs in the lateral chords of L4

  4. In Vitro, In Silico and In Vivo Studies of Ursolic Acid as an Anti-Filarial Agent

    PubMed Central

    Kalani, Komal; Kushwaha, Vikas; Sharma, Pooja; Verma, Richa; Srivastava, Mukesh; Khan, Feroz; Murthy, P. K.; Srivastava, Santosh Kumar

    2014-01-01

    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. PMID:25375886

  5. Serum dependent cell-mediated immune reactions to Brugia pahangi infective larvae.

    PubMed

    Chandrashekar, R; Rao, U R; Subrahmanyam, D

    1985-11-01

    Fresh normal rat serum (fNRS) promoted adherence and cytotoxicity of albino rat neutrophils and macrophages to Brugia pahangi infective larvae (L3) in vitro. EDTA and not EGTA abolished the adherence activity suggesting the involvement of complement components via the alternate pathway. C3 molecules were detected on the surface of the parasite by immunofluorescence. fNRS depleted of complement by treatment with Zymosan A or of factor B by heating at 50 degrees C for 20 min, failed to promote cell adherence to the parasite. fNRS and cells from albino rat were more potent in inducing cytotoxicity to L3 than those from jird or Mastomys which may reflect the greater resistance offered by the albino rat to B. pahangi infection. In the presence of IgG and a heat labile factor, possibly complement, of immune serum, neutrophils and macrophages and to a lesser extent eosinophils adhered to and killed the larvae. Immune sera raised against microfilariae of different filarial parasites promoted cell-mediated cytotoxicity to B. pahangi L3 suggesting sharing of antigens between the two stages.

  6. Analysis of Transcriptional Regulation of Tetracycline Responsive Genes in Brugia malayi

    PubMed Central

    Liu, Canhui; Kelen, Patrick Vander; Ghedin, Elodie; Lustigman, Sara; Unnasch, Thomas R.

    2011-01-01

    The Wolbachia endosymbiont of the human filarial parasites is necessary for parasite reproduction, making it an attractive chemotherapeutic target. Previous studies have demonstrated that mRNA levels of several nuclearly encoded genes are altered as a result of exposure to antibiotics that eliminate the endosymbiont, suggesting that they may be involved in maintaining the parasite-endosymbiont relationship. Here, we tested the hypothesis that the increase in mRNA levels of certain nuclearly encoded genes of Brugia malayi in response to tetracycline treatment involved specific regulatory elements present in the promoters of these genes. The promoters of three such genes (BmRPL13, BmRPS4 and BmHSP70) were tested for tetracycline responsiveness utilizing a homologous transient transcription system. Reporter gene expression driven by all three promoters was up-regulated in transfected embryos exposed to tetracycline. Substitution mutagenesis was employed to map the cis-acting elements responsible for this response in the BmHSP70 promoter. Tetracycline responsiveness was found to be distinct from the cis-acting elements involved in regulating the stress response from the BmHSP70 promoter; rather, tetracycline responsiveness was mediated by a TATAA-box like element. This study represents the first demonstration of small molecule-mediated gene regulation of a native B. malayi promoter. PMID:21944995

  7. Reactive oxygen species production and Brugia pahangi survivorship in Aedes polynesiensis with artificial Wolbachia infection types.

    PubMed

    Andrews, Elizabeth S; Crain, Philip R; Fu, Yuqing; Howe, Daniel K; Dobson, Stephen L

    2012-01-01

    Heterologous transinfection with the endosymbiotic bacterium Wolbachia has been shown previously to induce pathogen interference phenotypes in mosquito hosts. Here we examine an artificially infected strain of Aedes polynesiensis, the primary vector of Wuchereria bancrofti, which is the causative agent of Lymphatic filariasis (LF) throughout much of the South Pacific. Embryonic microinjection was used to transfer the wAlbB infection from Aedes albopictus into an aposymbiotic strain of Ae. polynesiensis. The resulting strain (designated "MTB") experiences a stable artificial infection with high maternal inheritance. Reciprocal crosses of MTB with naturally infected wild-type Ae. polynesiensis demonstrate strong bidirectional incompatibility. Levels of reactive oxygen species (ROS) in the MTB strain differ significantly relative to that of the wild-type, indicating an impaired ability to regulate oxidative stress. Following a challenge with Brugia pahangi, the number of filarial worms achieving the infective stage is significantly reduced in MTB as compared to the naturally infected and aposymbiotic strains. Survivorship of MTB differed significantly from that of the wild-type, with an interactive effect between survivorship and blood feeding. The results demonstrate a direct correlation between decreased ROS levels and decreased survival of adult female Aedes polynesiensis. The results are discussed in relation to the interaction of Wolbachia with ROS production and antioxidant expression, iron homeostasis and the insect immune system. We discuss the potential applied use of the MTB strain for impacting Ae. polynesiensis populations and strategies for reducing LF incidence in the South Pacific.

  8. Differential effects of diethylcarbamazine, tetracycline and the combination on Brugia pahangi adult females in vitro.

    PubMed

    Gunawardena, Nipul Kithsiri; Fujimaki, Yasunori; Aoki, Yoshiki; Mishima, Noriko; Ezaki, Takayuki; Uni, Shigehiko; Kimura, Eisaku

    2005-12-01

    Anti-filarial effects of diethylcarbamazine (DEC), tetracycline (TC) and the combination on Brugia pahangi adult females were studied in 7-day cell-free culture, in terms of microfilaria release, parasite motility, MTT assay for parasite viability and embryogram. TC 50 microg/ml (TC50) effectively reduced microfilaria release from day 1 of culture. Combined with DEC 100 microg/ml (DEC100) or DEC 500 microg/ml (DEC500), microfilaria release reduced further and synergistically. TC50 also reduced motility, but DEC100 and DEC500 did not. The combination of TC50 and DEC500 reduced motility synergistically. The MTT assay supported the results of motility study in general. The embryogram showed that only DEC500 reduced the total number of intrauterine embryos, especially ova, indicating that DEC500 inhibited early embryogenesis. TC50 did not affect the total number of embryos, but resulted in apparent accumulation of microfilariae in the uterus, suggesting that the drug inhibited release of microfilariae in this in vitro system. These results clarified different anti-female mechanisms between DEC and TC. A PCR-based study showed that endosymbiont bacteria, Wolbachia, in B. pahangi females decreased significantly after TC treatment. However, this study could not determine whether the effects of TC were direct or Wolbachia-mediated.

  9. Localization of a filarial phosphate permease that is up-regulated in response to depletion of essential Wolbachia endobacteria.

    PubMed

    Arumugam, Sridhar; Hoerauf, Achim; Pfarr, Kenneth M

    2014-03-01

    Wolbachia of filarial nematodes are essential, obligate endobacteria. When depleted by doxycycline worm embryogenesis, larval development and worm survival are inhibited. The molecular basis governing the endosymbiosis between Wolbachia and their filarial host is still being deciphered. In rodent filarial nematode Litomosoides sigmodontis, a nematode encoded phosphate permease gene (Ls-ppe-1) was up-regulated at the mRNA level in response to Wolbachia depletion and this gene promises to have an important role in Wolbachia-nematode endosymbiosis. To further characterize this gene, the regulation of phosphate permease during Wolbachia depletion was studied at the protein level in L. sigmodontis and in the human filaria Onchocerca volvulus. And the localization of phosphate permease (PPE) and Wolbachia in L. sigmodontis and O. volvulus was investigated in untreated and antibiotic treated worms. Depletion of Wolbachia by tetracycline (Tet) resulted in up-regulation of Ls-ppe-1 in L. sigmodontis. On day 36 of Tet treatment, compared to controls (Con), >98% of Wolbachia were depleted with a 3-fold increase in mRNA levels of Ls-ppe-1. Anti-Ls-PPE serum used in Western blots showed up-regulation of Ls-PPE at the protein level in Tet worms on day 15 and 36 of treatment. Immunohistology revealed the localization of Wolbachia and Ls-PPE in the embryos, microfilariae and hypodermis of L. sigmodontis female worms and up-regulation of Ls-PPE in response to Wolbachia depletion. Expression of O. volvulus phosphate permease (Ov-PPE) studied using anti-Ov-PPE serum, showed up-regulation of Ov-PPE at the protein level in doxycycline treated Wolbachia depleted O. volvulus worms and immunohistology revealed localization of Ov-PPE and Wolbachia and up-regulation of Ov-PPE in the hypodermis and embryos of doxycycline treated worms. Ls-PPE and Ov-PPE are upregulated upon Wolbachia depletion in same tissues and regions where Wolbachia are located in untreated worms, reinforcing a link

  10. A Potential Role for the Interaction of Wolbachia Surface Proteins with the Brugia malayi Glycolytic Enzymes and Cytoskeleton in Maintenance of Endosymbiosis

    PubMed Central

    Melnikow, Elena; Xu, Shulin; Liu, Jing; Bell, Aaron J.; Ghedin, Elodie; Unnasch, Thomas R.; Lustigman, Sara

    2013-01-01

    The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium of the genus Wolbachia. The Wolbachia represent an attractive target for the control of filarial induced disease as elimination of the bacteria affects molting, reproduction and survival of the worms. The molecular basis for the symbiotic relationship between Wolbachia and their filarial hosts has yet to be elucidated. To identify proteins involved in this process, we focused on the Wolbachia surface proteins (WSPs), which are known to be involved in bacteria-host interactions in other bacterial systems. Two WSP-like proteins (wBm0152 and wBm0432) were localized to various host tissues of the B. malayi female adult worms and are present in the excretory/secretory products of the worms. We provide evidence that both of these proteins bind specifically to B. malayi crude protein extracts and to individual filarial proteins to create functional complexes. The wBm0432 interacts with several key enzymes involved in the host glycolytic pathway, including aldolase and enolase. The wBm0152 interacts with the host cytoskeletal proteins actin and tubulin. We also show these interactions in vitro and have verified that wBm0432 and B. malayi aldolase, as well as wBm0152 and B. malayi actin, co-localize to the vacuole surrounding Wolbachia. We propose that both WSP protein complexes interact with each other via the aldolase-actin link and/or via the possible interaction between the host's enolase and the cytoskeleton, and play a role in Wolbachia distribution during worm growth and embryogenesis. PMID:23593519

  11. A potential role for the interaction of Wolbachia surface proteins with the Brugia malayi glycolytic enzymes and cytoskeleton in maintenance of endosymbiosis.

    PubMed

    Melnikow, Elena; Xu, Shulin; Liu, Jing; Bell, Aaron J; Ghedin, Elodie; Unnasch, Thomas R; Lustigman, Sara

    2013-01-01

    The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium of the genus Wolbachia. The Wolbachia represent an attractive target for the control of filarial induced disease as elimination of the bacteria affects molting, reproduction and survival of the worms. The molecular basis for the symbiotic relationship between Wolbachia and their filarial hosts has yet to be elucidated. To identify proteins involved in this process, we focused on the Wolbachia surface proteins (WSPs), which are known to be involved in bacteria-host interactions in other bacterial systems. Two WSP-like proteins (wBm0152 and wBm0432) were localized to various host tissues of the B. malayi female adult worms and are present in the excretory/secretory products of the worms. We provide evidence that both of these proteins bind specifically to B. malayi crude protein extracts and to individual filarial proteins to create functional complexes. The wBm0432 interacts with several key enzymes involved in the host glycolytic pathway, including aldolase and enolase. The wBm0152 interacts with the host cytoskeletal proteins actin and tubulin. We also show these interactions in vitro and have verified that wBm0432 and B. malayi aldolase, as well as wBm0152 and B. malayi actin, co-localize to the vacuole surrounding Wolbachia. We propose that both WSP protein complexes interact with each other via the aldolase-actin link and/or via the possible interaction between the host's enolase and the cytoskeleton, and play a role in Wolbachia distribution during worm growth and embryogenesis.

  12. Comparative Analysis of Glycosylated and Nonglycosylated Filarial Homologues of the 20-Kilodalton Retinol Binding Protein from Onchocerca volvulus (Ov20)

    PubMed Central

    Nirmalan, Niroshini; Cordeiro, N. J. V.; Kläger, Sabine L.; Bradley, Janette E.; Allen, Judith E.

    1999-01-01

    Ov20 is a structurally novel 20-kDa retinol binding protein secreted by Onchocerca volvulus. Immunological and biological investigation of this protein has been hampered by the inability to maintain O. volvulus in a laboratory setting. In an effort to find a system more amenable to laboratory investigation, we have cloned, sequenced, and expressed cDNA encoding homologues of Ov20 from two closely related filarial species, Brugia malayi (Bm20) and Acanthocheilonema viteae (Av20). Sequence comparisons have highlighted differences in glycosylation of the homologues. We present here an analysis of mouse immune responses to Ov20, Bm20, and Av20. The results suggest a strong genetic restriction in response to native Bm20 that is overcome when recombinant, nonnative material is used. Reactivity of human filarial sera to the three recombinant proteins confirmed previous specificity studies with Ov20 but highlighted important differences in the reactivity patterns of the O. volvulus and B. malayi homologues that may be due to differences in glycosylation patterns. Ov20 is a dominant antigen in infected individuals, while Bm20 is not. The availability of the B. malayi homologue enabled us to use defined murine reagents and inbred strains for genetic analysis of responsiveness in a way that is not possible for Ov20. However, the close sequence similarity between Ov20 and Av20 suggests that the A. viteae model may be more suited to the investigation of the biological functions of Ov20. PMID:10569745

  13. Rapid Detection and Identification of Wuchereria bancrofti, Brugia malayi, B. pahangi, and Dirofilaria immitis in Mosquito Vectors and Blood Samples by High Resolution Melting Real-Time PCR

    PubMed Central

    Thanchomnang, Tongjit; Intapan, Pewpan M.; Tantrawatpan, Chairat; Lulitanond, Viraphong; Chungpivat, Sudchit; Taweethavonsawat, Piyanan; Kaewkong, Worasak; Sanpool, Oranuch; Janwan, Penchom; Choochote, Wej

    2013-01-01

    A simple, rapid, and high-throughput method for detection and identification of Wuchereria bancrofti, Brugia malayi, Brugia pahangi, and Dirofilaria immitis in mosquito vectors and blood samples was developed using a real-time PCR combined with high-resolution melting (HRM) analysis. Amplicons of the 4 filarial species were generated from 5S rRNA and spliced leader sequences by the real-time PCR and their melting temperatures were determined by the HRM method. Melting of amplicons from W. bancrofti, B. malayi, D. immitis, and B. pahangi peaked at 81.5±0.2℃, 79.0±0.3℃, 76.8±0.1℃, and 79.9±0.1℃, respectively. This assay is relatively cheap since it does not require synthesis of hybridization probes. Its sensitivity and specificity were 100%. It is a rapid and technically simple approach, and an important tool for population surveys as well as molecular xenomonitoring of parasites in vectors. PMID:24516268

  14. Rapid detection of Wuchereria bancrofti and Brugia malayi in mosquito vectors (Diptera: Culicidae) using a real-time fluorescence resonance energy transfer multiplex PCR and melting curve analysis.

    PubMed

    Intapan, Pewpan M; Thanchomnang, Tongjit; Lulitanond, Viraphong; Maleewong, Wanchai

    2009-01-01

    We developed a single-step real-time fluorescence resonance energy transfer (FRET) multiplex polymerase chain reaction (PCR) merged with melting curve analysis for the detection of Wuchereria bancrofti and Brugia malayi DNA in blood-fed mosquitoes. Real-time FRET multiplex PCR is based on fluorescence melting curve analysis of a hybrid of amplicons generated from two families of repeated DNA elements: the 188 bp SspI repeated sequence, specific to W. bancrofti, and the 153-bp HhaI repeated sequence, specific to the genus Brugia and two pairs of specific fluorophore-labeled probes. Both W. bancrofti and B. malayi can be differentially detected in infected vectors by this process through their different fluorescence channel and melting temperatures. The assay could distinguish both human filarial DNAs in infected vectors from the DNAs of Dirofilaria immitis- and Plasmodium falciparum-infected human red blood cells and noninfected mosquitoes and human leukocytes. The technique showed 100% sensitivity and specificity and offers a rapid and reliable procedure for differentially identifying lymphatic filariasis. The introduced real-time FRET multiplex PCR can reduce labor time and reagent costs and is not prone to carry over contamination. The test can be used to screen mosquito vectors in endemic areas and therefore should be a useful diagnostic tool for the evaluation of infection rate of the mosquito populations and for xenomonitoring in the community after eradication programs such as the Global Program to Eliminate Lymphatic Filariasis.

  15. Rapid detection and identification of Wuchereria bancrofti, Brugia malayi, B. pahangi, and Dirofilaria immitis in mosquito vectors and blood samples by high resolution melting real-time PCR.

    PubMed

    Thanchomnang, Tongjit; Intapan, Pewpan M; Tantrawatpan, Chairat; Lulitanond, Viraphong; Chungpivat, Sudchit; Taweethavonsawat, Piyanan; Kaewkong, Worasak; Sanpool, Oranuch; Janwan, Penchom; Choochote, Wej; Maleewong, Wanchai

    2013-12-01

    A simple, rapid, and high-throughput method for detection and identification of Wuchereria bancrofti, Brugia malayi, Brugia pahangi, and Dirofilaria immitis in mosquito vectors and blood samples was developed using a real-time PCR combined with high-resolution melting (HRM) analysis. Amplicons of the 4 filarial species were generated from 5S rRNA and spliced leader sequences by the real-time PCR and their melting temperatures were determined by the HRM method. Melting of amplicons from W. bancrofti, B. malayi, D. immitis, and B. pahangi peaked at 81.5±0.2℃, 79.0±0.3℃, 76.8±0.1℃, and 79.9±0.1℃, respectively. This assay is relatively cheap since it does not require synthesis of hybridization probes. Its sensitivity and specificity were 100%. It is a rapid and technically simple approach, and an important tool for population surveys as well as molecular xenomonitoring of parasites in vectors.

  16. Tunga penetrans: molecular identification of Wolbachia endobacteria and their recognition by antibodies against proteins of endobacteria from filarial parasites.

    PubMed

    Fischer, Peter; Schmetz, Christel; Bandi, Claudio; Bonow, Insa; Mand, Sabine; Fischer, Kerstin; Büttner, Dietrich W

    2002-01-01

    In search of Wolbachia in human parasites, Wolbachia were identified in the sand flea Tunga penetrans. PCR and DNA sequencing of the bacterial 16S rDNA, the ftsZ cell division protein, the Wolbachia surface protein (wsp) and the Wolbachia aspartate aminotransferase genes revealed a high similarity to the respective sequences of endosymbionts of filarial nematodes. Using these sequences a phylogenetic tree was generated, that indicates a close relationship between Wolbachia from T. penetrans and from filarial parasites, but possibly as a member of a new supergroup. Ultrastructural studies showed that Wolbachia are abundant in the ovaries of neosomic fleas, whereas other, smaller and morphologically distinct, bacteria were observed in the lumen of the intestine. Wolbachia were labeled by immunohistology and immunogold electron microscopy using polyclonal antibodies against wsp of Drosophila, of the filarial parasite Dirofilaria immitis, or against hsp 60 from Yersinia enterocolitica. These results show that as in filariasis, humans with tungiasis are exposed to Wolbachia. Furthermore, antisera raised against proteins of Wolbachia from arthropods or from filarial parasites can be immunologically cross-reactive.

  17. Co-infection restrains Litomosoides sigmodontis filarial load and plasmodial P. yoelii but not P. chabaudi parasitaemia in mice

    PubMed Central

    Karadjian, Gregory; Berrebi, Dominique; Dogna, Nathalie; Vallarino-Lhermitte, Nathaly; Bain, Odile; Landau, Irène; Martin, Coralie

    2014-01-01

    Infection with multiple parasite species is clearly the norm rather than the exception, in animals as well as in humans. Filarial nematodes and Plasmodium spp. are important parasites in human public health and they are often co-endemic. Interactions between these parasites are complex. The mechanisms underlying the modulation of both the course of malaria and the outcome of filarial infection are poorly understood. Despite increasing activity in recent years, studies comparing co- and mono-infections are very much in their infancy and results are contradictory at first sight. In this study we performed controlled and simultaneous co-infections of BALB/c mice with Litomosoides sigmodontis filaria and with Plasmodium spp. (Plasmodium yoelii 17 XNL or Plasmodium chabaudi 864VD). An analysis of pathological lesions in the kidneys and lungs and a parasitological study were conducted at different times of infection. Whatever the plasmodial species, the filarial recovery rate was strongly decreased. The peak of parasitaemia in the plasmodial infection was decreased in the course of P. yoelii infection but not in that of P. chabaudi. Regarding pathological lesions, L. sigmodontis can reverse lesions in the kidneys due to the presence of both Plasmodium species but does not modify the course of pulmonary lesions. The filarial infection induces granulomas in the lungs. PMID:24717449

  18. Whole-cell patch-clamp recording of nicotinic acetylcholine receptors in adult Brugia malayi muscle

    PubMed Central

    Robertson, A. P.; Buxton, S. K.; Martin, R. J.

    2013-01-01

    Lymphatic filariasis is a debilitating disease caused by clade III parasites like Brugia malayi and Wuchereria bancrofti. Current recommended treatment regimen for this disease relies on albendazole, ivermectin and diethylcarbamazine, none of which targets the nicotinic acetylcholine receptors in these parasitic nematodes. Our aim therefore has been to develop adult B. malayi for electrophysiological recordings to aid in characterizing the ion channels in this parasite as anthelmintic target sites. In that regard, we recently demonstrated the amenability of adult B. malayi to patch-clamp recordings and presented results on the single-channel properties of nAChR in this nematode. We have built on this by recording whole-cell nAChR currents from adult B. malayi muscle. Acetylcholine, levamisole, pyrantel, bephenium and tribendimidine activated the receptors on B. malayi muscle, producing robust currents ranging from > 200 pA to ~1.5 nA. Levamisole completely inhibited motility of the adult B. malayi within 10 min and after 60 min, motility had recovered back to control values. PMID:23562945

  19. Brugia malayi microfilariae adhere to human vascular endothelial cells in a C3-dependent manner

    PubMed Central

    Schroeder, Jan-Hendrik; McCarthy, David; Szestak, Tadge; Cook, Darren A.; Taylor, Mark J.; Craig, Alister G.; Lawson, Charlotte; Lawrence, Rachel A.

    2017-01-01

    Brugia malayi causes the human tropical disease, lymphatic filariasis. Microfilariae (Mf) of this nematode live in the bloodstream and are ingested by a feeding mosquito vector. Interestingly, in a remarkable co-evolutionary adaptation, Mf appearance in the peripheral blood follows a circadian periodicity and reaches a peak when the mosquito is most likely to feed. For the remaining hours, the majority of Mf sequester in the lung capillaries. This circadian phenomenon has been widely reported and is likely to maximise parasite fitness and optimise transmission potential. However, the mechanism of Mf sequestration in the lungs remains largely unresolved. In this study, we demonstrate that B. malayi Mf can, directly adhere to vascular endothelial cells under static conditions and under flow conditions, they can bind at high (but not low) flow rates. High flow rates are more likely to be experienced diurnally. Furthermore, a non-periodic nematode adheres less efficiently to endothelial cells. Strikingly C3, the central component of complement, plays a crucial role in the adherence interaction. These novel results show that microfilariae have the ability to bind to endothelial cells, which may explain their sequestration in the lungs, and this binding is increased in the presence of inflammatory mediators. PMID:28481947

  20. Molecular genetics analysis for co-infection of Brugia malayi and Brugia pahangi in cat reservoirs based on internal transcribed spacer region 1.

    PubMed

    Areekit, Supatra; Khuchareontaworn, Sintawee; Kanjanavas, Pornpimon; Sriyapai, Thayat; Pakpitchareon, Arda; Khawsak, Paisarn; Chansiri, Kosum

    2009-01-01

    This study described the diagnosis of a mixed infection of Brugia malayi and Brugia pahangi in a single domestic cat using the internal transcribed spacer 1 (ITS1) region. Following polymerase chain reaction amplification of the ITS1 region, the 580 bp amplicon was cloned, and 29 white colonies were randomly selected for DNA sequencing and phylogenetic tree construction. A DNA parsimony tree generated two groups of Brugia spp with one group containing 6 clones corresponding to B. pahangi and the other 23 clones corresponding to B. malayi. This indicated that mixed infection of the two Brugia spp, B. pahangi and B. malayi, had occurred in a single host.

  1. Inducible costimulator is required for type 2 antibody isotype switching but not T helper cell type 2 responses in chronic nematode infection

    PubMed Central

    Loke, P'ng; Zang, Xingxing; Hsuan, Lisa; Waitz, Rebecca; Locksley, Richard M.; Allen, Judith E.; Allison, James P.

    2005-01-01

    Inducible costimulator (ICOS) has been suggested to perform an important role in T helper cell type 2 (Th2) responses, germinal center formation, and isotype switching. The role of ICOS in chronic Th2 responses was studied in a nematode model with the filarial parasite, Brugia malayi. Contrary to expectations, we did not observe a significant defect in IL-4-producing Th2 cells in ICOS–/– mice or in eosinophil recruitment. We also found that ICOS was not required for the differentiation of alternatively activated macrophages (AAMΦ) that express Ym1 and Fizz1. Although the production of IgE was slightly reduced in ICOS–/– mice, this was not as significant as in CD28–/– mice. In contrast to live infection, the primary response of ICOS–/– mice immunized with soluble B. malayi antigen and complete Freund's adjuvant resulted in significantly fewer IL-4-producing cells in the lymph nodes. As previously reported, we observed a defect in antibody isotype switching toward the IgG1 isotype in ICOS–/– mice during live infection. Interestingly, there was a significant enhancement of parasite-specific IgG3 isotype antibodies. CD28–/– and MHC class II–/– mice also had enhanced parasite-specific IgG3 isotype antibodies. Our results suggest that ICOS is not required to maintain a chronic cellular Th2 response. The primary role of ICOS in a chronic helminth infection could be to drive antibodies toward type 2 isotypes. T-independent antibody response to the parasite could be enhanced in the absence of costimulation and T cell help. PMID:15994233

  2. Distribution of Brugia malayi larvae and DNA in vector and non-vector mosquitoes: implications for molecular diagnostics

    PubMed Central

    2009-01-01

    Background The purpose of this study was to extend prior studies of molecular detection of Brugia malayi DNA in vector (Aedes aegypti- Liverpool) and non-vector (Culex pipiens) mosquitoes at different times after ingestion of infected blood. Results Parasite DNA was detected over a two week time course in 96% of pooled thoraces of vector mosquitoes. In contrast, parasite DNA was detected in only 24% of thorax pools from non-vectors; parasite DNA was detected in 56% of midgut pools and 47% of abdomen pools from non-vectors. Parasite DNA was detected in vectors in the head immediately after the blood meal and after 14 days. Parasite DNA was also detected in feces and excreta of the vector and non-vector mosquitoes which could potentially confound results obtained with field samples. However, co-housing experiments failed to demonstrate transfer of parasite DNA from infected to non-infected mosquitoes. Parasites were also visualized in mosquito tissues by immunohistololgy using an antibody to the recombinant filarial antigen Bm14. Parasite larvae were detected consistently after mf ingestion in Ae. aegypti- Liverpool. Infectious L3s were seen in the head, thorax and abdomen of vector mosquitoes 14 days after Mf ingestion. In contrast, parasites were only detected by histology shortly after the blood meal in Cx. pipiens, and these were not labeled by the antibody. Conclusion This study provides new information on the distribution of filarial parasites and parasite DNA in vector and non-vector mosquitoes. This information should be useful for those involved in designing and interpreting molecular xenomonitoring studies. PMID:19922607

  3. Characterization of the allergen filarial tropomyosin with an invertebrate specific monoclonal antibody.

    PubMed

    Sereda, Michal J; Hartmann, Susanne; Büttner, Dietrich W; Volkmer, Rudolf; Hovestädt, Marc; Brattig, Norbert; Lucius, Richard

    2010-10-01

    Tropomyosins of invertebrates are pan-allergens responsible for wide spread allergic reactions against seafood and arthropods. As invertebrate tropomyosins are highly conserved, helminth tropomyosins are likely to show properties similar to these medically important allergens. Studies with a monoclonal antibody, NR1, raised against tropomyosin of the rodent filarial nematode Acanthocheilonema viteae revealed a B cell epitope common to helminths and marine mollusks, which does not occur in vertebrate tropomyosin. This antibody detected tropomyosin of A. viteae, other filariids, nematodes, trematodes and a cestode, and recognized as well tropomyosin of oyster, squid and octopus, but not of arthropods and vertebrates. Immunohistological analyses of A. viteae, Onchocerca volvulus and other nematodes using NR1 showed that tropomyosin is located in the fibrillar part of the body wall muscles and the uterus, and is also conspicuous in muscles of the pharynx, the vagina and other organs of the nematodes. The abundance of a pan-allergen like tropomyosin in parasitic worms and the counterintuitive, but well documented protection against allergic reactivity by some chronic helminth infections is discussed.

  4. Circulating filarial antigen detection in brugian filariasis.

    PubMed

    Tripathi, Praveen Kumar; Mahajan, Ramesh Chander; Malla, Nancy; Mewara, Abhishek; Bhattacharya, Shailja Misra; Shenoy, Ranganatha Krishna; Sehgal, Rakesh

    2016-03-01

    Human lymphatic filariasis (LF) is a major cause of disability globally. The success of global elimination programmes for LF depends upon effectiveness of tools for diagnosis and treatment. In this study on stage-specific antigen detection in brugian filariasis, L3, adult worm (AW) and microfilarial antigenaemia were detected in around 90-95% of microfilariae carriers (MF group), 50-70% of adenolymphangitis (ADL) patients, 10-25% of chronic pathology (CP) patients and 10-15% of endemic normal (EN) controls. The sensitivity of the circulating filarial antigen (CFA) detection in serum samples from MF group was up to 95%. In sera from ADL patients, unexpectedly, less antigen reactivity was observed. In CP group all the CFA positive individuals were from CP grade I and II only and none from grade III or IV, suggesting that with chronicity the AWs lose fecundity and start to disintegrate and die. Amongst EN subject, 10-15% had CFA indicating that few of them harbour filarial AWs, thus they might not be truly immune as has been conventionally believed. The specificity for antigen detection was 100% when tested with sera from various other protozoan and non-filarial helminthic infections.

  5. Immunological evaluation of an rsmD-like rRNA methyltransferase from Wolbachia endosymbiont of Brugia malayi.

    PubMed

    Rana, Ajay Kumar; Kushwaha, Susheela; Singh, Prashant Kumar; Misra-Bhattacharya, Shailja

    2016-02-01

    Wolbachia is a wonderful anti-filarial target with many of its enzymes and surface proteins (WSPs) representing potential drug targets and vaccine candidates. Here we report on the immunologic response of a drug target, rsmD-like rRNA methyltransferase from Wolbachia endosymbiont of Brugia malayi. The recombinant protein generated both humoral and cell-mediated response in BALB/c mice but compromised its immunity. The humoral response was transient and endured barely for six months in mice with or without B. Malayi challenge. In splenocytes of mice, the key humoral immunity mediating cytokine IL4 was lowered (IL4↓) while IFNγ, the major cytokine mediating cellular immunity was decreased along with upregulation of IL10 cytokine (IFNγ↓, IL10↑). The finding here indicates that the enzyme has low immunogenicity and triggers lowering of cytokine level in BALB/c mice. Interestingly the overall immune profile can be summed up with equivalent response generated by WSP or whole Wolbachia.

  6. Breakdown of coevolution between symbiotic bacteria Wolbachia and their filarial hosts.

    PubMed

    Lefoulon, Emilie; Bain, Odile; Makepeace, Benjamin L; d'Haese, Cyrille; Uni, Shigehiko; Martin, Coralie; Gavotte, Laurent

    2016-01-01

    Wolbachia is an alpha-proteobacterial symbiont widely distributed in arthropods. Since the identification of Wolbachia in certain animal-parasitic nematodes (the Onchocercidae or filariae), the relationship between arthropod and nematode Wolbachia has attracted great interest. The obligate symbiosis in filariae, which renders infected species susceptible to antibiotic chemotherapy, was held to be distinct from the Wolbachia-arthropod relationship, typified by reproductive parasitism. While co-evolutionary signatures in Wolbachia-arthropod symbioses are generally weak, reflecting horizontal transmission events, strict co-evolution between filariae and Wolbachia has been reported previously. However, the absence of close outgroups for phylogenetic studies prevented the determination of which host group originally acquired Wolbachia. Here, we present the largest co-phylogenetic analysis of Wolbachia in filariae performed to date including: (i) a screening and an updated phylogeny of Wolbachia; (ii) a co-phylogenetic analysis; and (iii) a hypothesis on the acquisition of Wolbachia infection. First, our results show a general overestimation of Wolbachia occurrence and support the hypothesis of an ancestral absence of infection in the nematode phylum. The accuracy of supergroup J is also underlined. Second, although a global pattern of coevolution remains, the signal is derived predominantly from filarial clades associated with Wolbachia in supergroups C and J. In other filarial clades, harbouring Wolbachia supergroups D and F, horizontal acquisitions and secondary losses are common. Finally, our results suggest that supergroup C is the basal Wolbachia clade within the Ecdysozoa. This hypothesis on the origin of Wolbachia would change drastically our understanding of Wolbachia evolution.

  7. Breakdown of coevolution between symbiotic bacteria Wolbachia and their filarial hosts

    PubMed Central

    Lefoulon, Emilie; Makepeace, Benjamin L.; d’Haese, Cyrille; Uni, Shigehiko; Gavotte, Laurent

    2016-01-01

    Wolbachia is an alpha-proteobacterial symbiont widely distributed in arthropods. Since the identification of Wolbachia in certain animal-parasitic nematodes (the Onchocercidae or filariae), the relationship between arthropod and nematode Wolbachia has attracted great interest. The obligate symbiosis in filariae, which renders infected species susceptible to antibiotic chemotherapy, was held to be distinct from the Wolbachia-arthropod relationship, typified by reproductive parasitism. While co-evolutionary signatures in Wolbachia-arthropod symbioses are generally weak, reflecting horizontal transmission events, strict co-evolution between filariae and Wolbachia has been reported previously. However, the absence of close outgroups for phylogenetic studies prevented the determination of which host group originally acquired Wolbachia. Here, we present the largest co-phylogenetic analysis of Wolbachia in filariae performed to date including: (i) a screening and an updated phylogeny of Wolbachia; (ii) a co-phylogenetic analysis; and (iii) a hypothesis on the acquisition of Wolbachia infection. First, our results show a general overestimation of Wolbachia occurrence and support the hypothesis of an ancestral absence of infection in the nematode phylum. The accuracy of supergroup J is also underlined. Second, although a global pattern of coevolution remains, the signal is derived predominantly from filarial clades associated with Wolbachia in supergroups C and J. In other filarial clades, harbouring Wolbachia supergroups D and F, horizontal acquisitions and secondary losses are common. Finally, our results suggest that supergroup C is the basal Wolbachia clade within the Ecdysozoa. This hypothesis on the origin of Wolbachia would change drastically our understanding of Wolbachia evolution. PMID:27069790

  8. Evolutionary genomics place the origin of Wolbachia in nematodes, not arthropods

    USDA-ARS?s Scientific Manuscript database

    Wolbachia, the most widely studied endosymbiont in arthropods, is a target for biological control of mosquito-borne diseases (malaria and dengue virus), and antibiotic elimination of infectious filarial nematodes. We sequenced and analyzed the genome of a new strain (wPpe) in the plant-parasitic nem...

  9. Targeting Filarial Abl-like Kinases: Orally Available, Food and Drug Administration–Approved Tyrosine Kinase Inhibitors Are Microfilaricidal and Macrofilaricidal

    PubMed Central

    O'Connell, Elise M.; Bennuru, Sasisekhar; Steel, Cathy; Dolan, Michael A.; Nutman, Thomas B.

    2015-01-01

    Background. Elimination of onchocerciasis and lymphatic filariasis is targeted for 2020. Given the coincident Loa loa infections in Central Africa and the potential for drug resistance development, the need for new microfilaricides and macrofilaricides has never been greater. With the genomes of L. loa, Onchocerca volvulus, Wuchereria bancrofti, and Brugia malayi available, new drug targets have been identified. Methods. The effects of the tyrosine kinase inhibitors imatinib, nilotinib, and dasatinib on B. malayi adult males, adult females, L3 larvae, and microfilariae were assessed using a wide dose range (0–100 µM) in vitro. Results. For microfilariae, median inhibitory concentrations (IC50 values) on day 6 were 6.06 µM for imatinib, 3.72 µM for dasatinib, and 81.35 µM for nilotinib; for L3 larvae, 11.27 µM, 13.64 µM, and 70.98 µM, respectively; for adult males, 41.6 µM, 3.87 µM, and 68.22 µM, respectively; and for adult females, 42.89 µM, 9.8 µM, and >100 µM, respectively. Three-dimensional modeling suggests how these tyrosine kinase inhibitors bind and inhibit filarial protein activity. Conclusions. Given the safety of imatinib in humans, plans are underway for pilot clinical trials to assess its efficacy in patients with filarial infections. PMID:25657255

  10. [Discrimination of geographic strains of periodic Brugia malayi by the cuticular ornamentation of the male].

    PubMed

    Bain, O; Chandrasekharan, S A; Partono, F; Mak, J W; Zheng, H J; Seo, B S; Wu, S H

    1988-01-01

    study conveniently the morphology of microfilariae (often an excellent indication for speciation in that group of Nematodes) and, evenly, to proceed to parallel studies on isoenzymes. However, whatever could be the taxonomical conclusion, the differences observed in Brugia malayi originating from different regions appear to the sufficient to consider the existence of four distinct diseases.

  11. The n-hexane and chloroform fractions of Piper betle L. trigger different arms of immune responses in BALB/c mice and exhibit antifilarial activity against human lymphatic filarid Brugia malayi.

    PubMed

    Singh, Meghna; Shakya, Shilpy; Soni, Vishal Kumar; Dangi, Anil; Kumar, Nikhil; Bhattacharya, Shailja-Misra

    2009-06-01

    Modulation of immune functions by using herbal plants and their products has become fundamental regime of therapeutic approach. Piper betle Linn. (Piperaceae) is a widely distributed plant in the tropical and subtropical regions of the world and has been attributed as traditional herbal remedy for many diseases. We have recently reported the antifilarial and antileishmanial efficacy in the leaf extract of Bangla Mahoba landrace of P. betle which is a female plant. The present report describes the in vivo immunomodulatory efficacy of the crude methanolic extract and its n-hexane, chloroform, n-butanol fractions of the female plant at various dose levels ranging between 0.3 and 500 mg/kg in BALB/c. Attempts were also made to observe antifilarial activity of the active extracts and correlate it with the antigen specific immune responses in another rodent Mastomys coucha infected with human lymphatic filarial parasite Brugia malayi. The crude methanol extract and n-hexane fraction were found to potentiate significant (p<0.001) enhancement of both humoral (plaque forming cells, hemagglutination titre) as well as cell-mediated (lymphoproliferation, macrophage activation, delayed type hypersensitivity) immune responses in mice. The flow cytometric analysis of splenocytes of treated mice indicated enhanced population of T-cells (CD4(+), CD8(+)) and B-cells (CD19(+)). The n-hexane fraction (3 mg/kg) was found to induce biased type 2 cytokine response as revealed by increased IL-4(+) and decreased IFN-gamma(+) T-cell population while the chloroform fraction (10 mg/kg) produced a predominant type 1 cytokines. Crude methanolic extract (100 mg/kg) demonstrated a mixed type 1 and type 2 cytokine responses thus suggesting a remarkable immunomodulatory property in this plant. The induction of differential T-helper cell immune response appears ideal to overcome immunosuppression as observed in case of lymphatic, filarial Brugia malayi infection which may also be extended to other

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

    PubMed

    Koutsovoulos, Georgios; Makepeace, Benjamin; Tanya, Vincent N; Blaxter, Mark

    2014-06-01

    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.

  13. Palaeosymbiosis Revealed by Genomic Fossils of Wolbachia in a Strongyloidean Nematode

    PubMed Central

    Koutsovoulos, Georgios; Makepeace, Benjamin; Tanya, Vincent N.; Blaxter, Mark

    2014-01-01

    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. PMID:24901418

  14. Defining the target and the effect of imatinib on the filarial c-Abl homologue

    PubMed Central

    Kamenyeva, Olena; Lustigman, Sara; Bell, Aaron; Nutman, Thomas B.

    2017-01-01

    Background Previously we demonstrated the micro- and macrofilaricidal properties of imatinib in vitro. Here we use electron and multiphoton microscopy to define the target of imatinib in the adult and microfilarial stages of Brugia malayi and assess the effects of pharmacologically relevant levels of imatinib on the adult parasites. Methods After fixation of adult B. malayi males and females, sections were stained with polyclonal rabbit anti-c-Abl antibody (or isotype control) and imaged with multiphoton fluorescent microscopy. Microfilariae were fixed and labeled with rabbit anti-c-Abl IgG primary antibody followed by anti-rabbit gold conjugated secondary antibody and imaged using transmission electron microscopy (TEM; immunoEM). In addition, adult B. malayi males and females were exposed to 0 or 10μM of imatinib for 7 days following which they were prepared for transmission electron microscopy (TEM) to assess the drug’s effect on filarial ultrastructure. Results Fluorescent localization of anti-c-Abl antibody demonstrated widespread uptake in the adult filariae, but the most intense signal was seen in the reproductive organs, muscle, and intestine of both male and female worms. Fluorescence was significantly more intense in the early microfilarial stage (i.e. early morula) compared with later development stages (i.e. pretzel). Anti-c-Abl antibody in the microfilariae localized to the nuclei. Based on TEM assessment following imatinib exposure, imatinib appeared to be detrimental to embryogenesis in the adult female B. malayi. Conclusions At pharmacologically achievable concentrations of imatinib, embryogenesis is impaired and possibly halted in adult filariae. Imatinib is likely a slow microfilaricide due to interference in intra-nuclear processes, which are slowly detrimental to the parasite and not immediately lethal, and thus may be used to lower the levels of L. loa microfilariae before they are treated within the context of conventional mass drug

  15. Filarial dermatitis in a striped skunk.

    PubMed

    Saito, E K; Little, S E

    1997-10-01

    A striped skunk (Mephitis mephitis) from Kansas (USA) with severe diffuse dermatitis characterized by extensive alopecic areas, thickened skin, and multiple, scattered cutaneous abscesses on the dorsal aspect of the head, neck, and trunk was submitted for diagnostic evaluation. More than 50 nematodes identified as Filaria taxideae were found in the dorsal subcutaneous tissue. Histologic examination of the skin revealed multifocal pyogranulomatous inflammation with intralesional larvated nematode eggs, moderate orthokeratotic hyperkeratosis, and mild acanthosis. The lesions resemble those reported from badgers (Taxidea taxus) and a lesser panda (Ailurus fulgens) with dermatitis caused by Filaria taxideae. Although F. taxideae has been previously collected from skunks, this is the first report of filarid dermatitis caused by this nematode in a striped skunk.

  16. How to become a parasite - lessons from the genomes of nematodes.

    PubMed

    Dieterich, Christoph; Sommer, Ralf J

    2009-05-01

    The phylum Nematoda is biologically diverse; it includes parasites of plants and animals in addition to free-living taxa. To date, the genomes of six nematodes have been sequenced. Comparative analyses of these ecologically diverse nematodes are beginning to reveal the mechanisms by which parasites arise and how they evolve. Here, we discuss some emerging principles for the mechanisms and evolution of parasitism. First, horizontal gene transfer represents a common theme in nematode parasites. Second, the human parasite Brugia malayi lost otherwise essential genes most probably owing to the mutualistic relationship with a bacterial endosymbiont. Finally, some parasitic features evolved under free-living conditions. A recent study revealed a conserved endocrine mechanism controlling the formation of dauer and infective larvae in nematodes.

  17. Brugia malayi Microfilariae Induce a Regulatory Monocyte/Macrophage Phenotype That Suppresses Innate and Adaptive Immune Responses

    PubMed Central

    Venugopal, Gopinath; Rao, Gopala B.; Lucius, Richard; Srikantam, Aparna; Hartmann, Susanne

    2014-01-01

    Background Monocytes and macrophages contribute to the dysfunction of immune responses in human filariasis. During patent infection monocytes encounter microfilariae in the blood, an event that occurs in asymptomatically infected filariasis patients that are immunologically hyporeactive. Aim To determine whether blood microfilariae directly act on blood monocytes and in vitro generated macrophages to induce a regulatory phenotype that interferes with innate and adaptive responses. Methodology and principal findings Monocytes and in vitro generated macrophages from filaria non-endemic normal donors were stimulated in vitro with Brugia malayi microfilarial (Mf) lysate. We could show that monocytes stimulated with Mf lysate develop a defined regulatory phenotype, characterised by expression of the immunoregulatory markers IL-10 and PD-L1. Significantly, this regulatory phenotype was recapitulated in monocytes from Wuchereria bancrofti asymptomatically infected patients but not patients with pathology or endemic normals. Monocytes from non-endemic donors stimulated with Mf lysate directly inhibited CD4+ T cell proliferation and cytokine production (IFN-γ, IL-13 and IL-10). IFN-γ responses were restored by neutralising IL-10 or PD-1. Furthermore, macrophages stimulated with Mf lysate expressed high levels of IL-10 and had suppressed phagocytic abilities. Finally Mf lysate applied during the differentiation of macrophages in vitro interfered with macrophage abilities to respond to subsequent LPS stimulation in a selective manner. Conclusions and significance Conclusively, our study demonstrates that Mf lysate stimulation of monocytes from healthy donors in vitro induces a regulatory phenotype, characterized by expression of PD-L1 and IL-10. This phenotype is directly reflected in monocytes from filarial patients with asymptomatic infection but not patients with pathology or endemic normals. We suggest that suppression of T cell functions typically seen in lymphatic

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

    PubMed Central

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

    2014-01-01

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

  19. The Effects of Ivermectin on Brugia malayi Females In Vitro: A Transcriptomic Approach.

    PubMed

    Ballesteros, Cristina; Tritten, Lucienne; O'Neill, Maeghan; Burkman, Erica; Zaky, Weam I; Xia, Jianguo; Moorhead, Andrew; Williams, Steven A; Geary, Timothy G

    2016-08-01

    Lymphatic filariasis and onchocerciasis are disabling and disfiguring neglected tropical diseases of major importance in developing countries. Ivermectin is the drug of choice for mass drug administration programs for the control of onchocerciasis and lymphatic filariasis in areas where the diseases are co-endemic. Although ivermectin paralyzes somatic and pharyngeal muscles in many nematodes, these actions are poorly characterized in adult filariae. We hypothesize that paralysis of pharyngeal pumping by ivermectin in filariae could result in deprivation of essential nutrients, especially iron, inducing a wide range of responses evidenced by altered gene expression, changes in metabolic pathways, and altered developmental states in embryos. Previous studies have shown that ivermectin treatment significantly reduces microfilariae release from females within four days of exposure in vivo, while not markedly affecting adult worms. However, the mechanisms responsible for reduced production of microfilariae are poorly understood. We analyzed transcriptomic profiles from Brugia malayi adult females, an important model for other filariae, using RNAseq technology after exposure in culture to ivermectin at various concentrations (100 nM, 300 nM and 1 μM) and time points (24, 48, 72 h, and 5 days). Our analysis revealed drug-related changes in expression of genes involved in meiosis, as well as oxidative phosphorylation, which were significantly down-regulated as early as 24 h post-exposure. RNA interference phenotypes of the orthologs of these down-regulated genes in C. elegans include "maternal sterile", "embryonic lethal", "larval arrest", "larval lethal" and "sick". These changes provide insight into the mechanisms involved in ivermectin-induced reduction in microfilaria output and impaired fertility, embryogenesis, and larval development.

  20. The Effects of Ivermectin on Brugia malayi Females In Vitro: A Transcriptomic Approach

    PubMed Central

    O’Neill, Maeghan; Burkman, Erica; Zaky, Weam I.; Xia, Jianguo; Moorhead, Andrew; Williams, Steven A.; Geary, Timothy G.

    2016-01-01

    Background Lymphatic filariasis and onchocerciasis are disabling and disfiguring neglected tropical diseases of major importance in developing countries. Ivermectin is the drug of choice for mass drug administration programs for the control of onchocerciasis and lymphatic filariasis in areas where the diseases are co-endemic. Although ivermectin paralyzes somatic and pharyngeal muscles in many nematodes, these actions are poorly characterized in adult filariae. We hypothesize that paralysis of pharyngeal pumping by ivermectin in filariae could result in deprivation of essential nutrients, especially iron, inducing a wide range of responses evidenced by altered gene expression, changes in metabolic pathways, and altered developmental states in embryos. Previous studies have shown that ivermectin treatment significantly reduces microfilariae release from females within four days of exposure in vivo, while not markedly affecting adult worms. However, the mechanisms responsible for reduced production of microfilariae are poorly understood. Methodology/Principal Findings We analyzed transcriptomic profiles from Brugia malayi adult females, an important model for other filariae, using RNAseq technology after exposure in culture to ivermectin at various concentrations (100 nM, 300 nM and 1 μM) and time points (24, 48, 72 h, and 5 days). Our analysis revealed drug-related changes in expression of genes involved in meiosis, as well as oxidative phosphorylation, which were significantly down-regulated as early as 24 h post-exposure. RNA interference phenotypes of the orthologs of these down-regulated genes in C. elegans include “maternal sterile”, “embryonic lethal”, “larval arrest”, “larval lethal” and “sick”. Conclusion/Significance These changes provide insight into the mechanisms involved in ivermectin-induced reduction in microfilaria output and impaired fertility, embryogenesis, and larval development. PMID:27529747

  1. Cofactor Independent Phosphoglycerate Mutase of Brugia malayi Induces a Mixed Th1/Th2 Type Immune Response and Inhibits Larval Development in the Host

    PubMed Central

    Singh, Prashant K.; Kushwaha, Susheela; Rana, Ajay K.; Misra-Bhattacharya, Shailja

    2014-01-01

    Lymphatic filariasis is a major debilitating disease, endemic in 72 countries putting more than 1.39 billion people at risk and 120 million are already infected. Despite the significant progress in chemotherapeutic advancements, there is still need for other measures like development of an effective vaccine or discovery of novel drug targets. In this study, structural and immunological characterization of independent phosphoglycerate mutase of filarial parasite Brugia malayi was carried out. Protein was found to be expressed in all major parasite life stages and as an excretory secretory product of adult parasites. Bm-iPGM also reacted to all the categories of human bancroftian patient's sera including endemic normals. In vivo immunological behaviour of protein was determined in immunized BALB/c mice followed by prophylactic analysis in BALB/c mice and Mastomys coucha. Immunization with Bm-iPGM led to generation of a mixed Th1/Th2 type immune response offering 58.2% protection against larval challenge in BALB/c and 65–68% protection in M. coucha. In vitro studies confirmed participation of anti-Bm-iPGM antibodies in killing of B. malayi infective larvae and microfilariae through ADCC mechanism. The present findings reveal potential immunoprotective nature of Bm-iPGM advocating its worth as an antifilarial vaccine candidate. PMID:25061608

  2. Recombinant trehalose-6-phosphate phosphatase of Brugia malayi cross-reacts with human Wuchereria bancrofti immune sera and engenders a robust protective outcome in mice.

    PubMed

    Kushwaha, Susheela; Singh, Prashant Kumar; Gupta, Jyoti; Soni, Vishal Kumar; Misra-Bhattacharya, Shailja

    2012-11-01

    Trehalose-6-phosphate phosphatase of Brugia malayi (Bm-TPP) represents an attractive vaccine candidate because it is present in all the major life stages of parasite, but is absent in mammals. We have previously cloned, purified and biochemically characterized Bm-TPP. In the present study, we investigated the cross-reactivity of recombinant Bm-TPP (r-Bm-TPP) with the sera of human bancroftian patients belonging to different disease categories. In silico study using bioinformatics tool demonstrated that Bm-TPP is highly immunogenic in nature. BALB/c mice administered with r-Bm-TPP alone or in combination with Freund's complete adjuvant (FCA) generated a strong IgG response. Further investigations on the antibody isotypes showed generation of a mixed T helper cell response which was marginally biased towards Th1 phenotype. r-Bm-TPP with or without adjuvant lead to significantly increased accumulation of CD4+ and CD8+ T cells in the spleen of infected mice and increased the activation of peritoneal macrophages. Additionally, r-Bm-TPP enhanced the production of both proinflammatory (IL-2, IFN-γ) and anti-inflammatory (IL-4, IL-10) cytokines and mice immunized with r-Bm-TPP alone or in combination with FCA showed 54.5% and 67% protection respectively against B. malayi infective larvae challenge. Taken together, our findings suggest that Bm-TPP is protective in nature and might be a potential candidate for development of vaccine against lymphatic filarial infections.

  3. Chemical constituents and antifilarial activity of Lantana camara against human lymphatic filariid Brugia malayi and rodent filariid Acanthocheilonema viteae maintained in rodent hosts.

    PubMed

    Misra, Namita; Sharma, Mithilesh; Raj, Kanwal; Dangi, Anil; Srivastava, Sudhir; Misra-Bhattacharya, Shailja

    2007-02-01

    Lymphatic filariasis continues to be a major health problem in tropical and subtropical countries. A macrofilaricidal agent capable of eliminating adult filarial parasites is urgently needed. In the present study, we report the antifilarial activity in the extract of stem portion of the plant Lantana camara. The crude extract at 1 g/kg for 5 days by oral route killed 43.05% of the adult Brugia malayi parasites and sterilized 76% of surviving female worms in the rodent model Mastomys coucha. A 34.5% adulticidal activity along with sterilization of 66% of female worms could be demonstrated in the chloroform fraction. Remarkable antifilarial activity was observed in the adult B. malayi transplanted gerbil model where up to 80% of the adult worms could be killed at the same dose and all the surviving female parasites were found sterilized. The extract was also found effective against a subcutaneous rodent filariid Acanthocheilonema viteae maintained in Mastomys coucha, where it exerted strong microfilaricidal (95.04%) and sterilization (60.66%) efficacy with mild macrofilaricidal action. Two compounds, oleanonic acid and oleanolic acid, isolated from hexane and chloroform fractions showed LC100 at 31.25 and 62.5 mug/ml, respectively, on B. malayi in vitro. This is the first ever report on the antifilarial efficacy of Lantana camara.

  4. Human innate lymphoid cells (ILCs) in filarial infections.

    PubMed

    Bonne-Année, S; Nutman, T B

    2017-05-15

    Filarial infections are characteristically chronic and can cause debilitating diseases governed by parasite-induced innate and adaptive immune responses. Filarial parasites traverse or establish niches in the skin (migrating infective larvae), in nonmucosal tissues (adult parasite niche) and in the blood or skin (circulating microfilariae) where they intersect with the host immune response. While several studies have demonstrated that filarial parasites and their antigens can modulate myeloid cells (monocyte, macrophage and dendritic cell subsets), T- and B-lymphocytes and skin resident cell populations, the role of innate lymphoid cells during filarial infections has only recently emerged. Despite the identification and characterization of innate lymphoid cells (ILCs) in murine helminth infections, little is actually known about the role of human ILCs during parasitic infections. The focus of this review will be to highlight the composition of ILCs in the skin, lymphatics and blood; where the host-parasite interaction is well-defined and to examine the role of ILCs during filarial infections. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  5. Fluorescent diethylcarbamazine analogues: sites of accumulation in Brugia malayi.

    PubMed

    Junnila, Amy; Bohle, D Scott; Prichard, Roger; Perepichka, Inna; Spina, Carla

    2007-01-01

    New fluorescein and rhodamine B-labeled antifilarial drug DEC analogues for use in drug localization studies with confocal microscopy have been prepared by a high-yield three-step synthesis. The resulting beta-amine-substituted DEC analogue has a single ethyl substituent which is beta-aminated to accommodate the fluorophore of either fluorescein isothiocyananate or rhodamine B. Confocal microscopy is used to show that the drug accumulates in the adult filarial worms in the pharynx, esophagus, and near the nerve ring of all adults, as well as in the uteri and vulva and the testes of the females and males.

  6. Molecular cloning, purification and characterization of Brugia malayi phosphoglycerate kinase.

    PubMed

    Kumar, Ranjeet; Doharey, Pawan Kumar; Saxena, Jitendra Kumar; Rathaur, Sushma

    2017-04-01

    Phosphoglycerate kinase (PGK) is a glycolytic enzyme present in many parasites. It has been reported as a candidate molecule for drug and vaccine developments. In the present study, a full-length cDNA encoding the Brugia malayi 3-phosphoglycerate kinase (BmPGK) with an open reading frame of 1.3 kb was isolated and PCR amplified and cloned. The exact size of the BmPGK's ORF is 1377 bps. The BmPGK gene was subcloned into pET-28a (+) expression vector, the expressed enzyme was purified by affinity column and characterized. The SDS-PAGE analysis revealed native molecular weight of recombinant Brugia malayi 3-phosphoglycerate kinase (rBmPGK) to be ∼45 kDa. The enzyme was found sensitive to temperature and pH, it showed maximum activity at 25 °C and pH 8.5. The Km values for PGA and ATP were 1.77 and 0.967 mM, respectively. The PGK inhibitor, clorsulon and antifilarial drugs albendazole and ivermectin inhibited the enzyme. The specific inhibitor of PGK, clorsulon, competitively inhibited enzyme with Ki value 1.88 μM. Albendazole also inhibited PGK competitively with Ki value 35.39 μM. Further these inhibitory studies were confirmed by docking and molecular simulation of drugs with enzyme. Clorsulon interacted with substrate binding site with glutamine 37 as well as in hinge regions with aspartic acid 385 and valine 387 at ADP binding site. On the other hand albendazole interacted with asparagine 335 residues. These effects were in good association with binding interactions. Thus current study might help in designing and synthesis of effective inhibitors for this novel drug target and understanding their mode of interaction with the potent anthelmintic drugs.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

    Poole, Catherine B.; Li, Zhiru; Alhassan, Andy; Guelig, Dylan; Diesburg, Steven; Tanner, Nathan A.; Zhang, Yinhua; Evans, Thomas C.; LaBarre, Paul; Wanji, Samuel; Burton, Robert A.; Carlow, Clotilde K. S.

    2017-01-01

    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. PMID:28199317

  9. Subcutaneously Administered Ultrafine PLGA Nanoparticles Containing Doxycycline Hydrochloride Target Lymphatic Filarial Parasites.

    PubMed

    Singh, Yuvraj; Srinivas, Adepu; Gangwar, Mamta; Meher, Jaya Gopal; Misra-Bhattacharya, Shailja; Chourasia, Manish K

    2016-06-06

    Systemic chemotherapeutic targeting of filarial parasites is unfocused due to their deep seated location in lymphatic vessels. This warrants a prolonged dosing regimen in high doses for an anthelmintic like doxycycline hydrochloride (DOX). In order to provide an alternative, we have constructed ultrafine PLGA nanoparticles of DOX (DPNPs), so as to exploit the peculiarity of lymphatic vasculature underneath the subcutaneous layer of skin, which preferentially allows entry of only 10-100 nm sized particles. DPNPs were constructed using a novel solvent diffusion method aided by probe sonication, which resulted in an average size 95.43 ± 0.8 nm as per DLS, PDI 0.168 ± 0.03, zeta potential -7.38 ± 0.32, entrapment efficiency 75.58 ± 1.94%, and refrigerator stability of 7 days with respect to size in the optimized batch. TEM further substantiated the spherical shape of DPNPs along with their actual nonhydrated size as being well below 100 nm. FTIR analysis of DOX, dummy nanoparticles, and freeze-dried DPNPs revealed that the formulation step did not induce prominent changes in the chemical nature of DOX. The drug release was significantly altered (p < 0.05) with 64.6 ± 1.67% release in 48 h from DPNPs and was dictated by Fickian diffusion. Pharmacokinetic studies in Wistar rats further revealed that DPNPs caused a 16-fold prolongation in attainment of plasma Tmax and a 2-fold extension of elimination half-life (28.569 ± 1.27 h) at a dose of 5 mg/kg when compared to native drug (DOX solution) of the same strength. Contrastingly the trend was reversed in regional lymph nodes where Cmax for DPNPs (820 ± 84 ng/mg) was 4-fold greater, and lymphatic Tmax was attained in one-fourth of what was required for DOX solution. This size based preferential lymphatic targeting resulted in significantly greater in vivo antifilarial activity of DPNPs when compared to DOX solution as gauged by several parameters in Brugia malayi infected Mastomys coucha. Interestingly, the

  10. Presence and formation of heme and occurrence of certain heme proteins in the filarial parasite Setaria digitata.

    PubMed

    Kumar, R A; Raj, R K

    1998-12-09

    There is currently renewed interest in the biological significance of heme proteins. The most common heme proteins include hemoglobin, myoglobin, cytochromes, and redox enzymes such as catalase and peroxidase. Setaria digitata is a cattle filarial parasite, which is devoid of typical cytochrome systems. However, studies showed activities of delta Aminolevulinate synthase (ALAS), delta Aminolevulinate dehydratase (ALAD), and heme oxygenase in appreciable amounts, suggesting the presence of necessary equipment for the biosynthesis of heme. This is further confirmed by the end product inhibition of ALAS by heme and the observation of the death of the parasite by succinyl acetone, an inhibitor of the biosynthesis of heme. Though typical cytochrome systems are absent, microsomal cytochrome P 450 and elevated levels of heme containing enzymes such as catalase and peroxidase are present in the parasite. A unique hemoglobin is also detected which shows a difference in biological functions from the host system and that of the much-studied nematode parasite Ascaris sum.

  11. IgG subclass responses to proinflammatory fraction of Brugia malayi in human filariasis

    PubMed Central

    Joseph, S.K.; Verma, S.K.; Sahoo, M.K.; Sharma, A.; Srivastava, M.; Reddy, M.V.R.; Murthy, P.K.

    2012-01-01

    Background & objectives: Earlier we demonstrated that immunization with F6, a proinflammatory molecular fraction isolated from the human filarial parasite Brugia malayi, protected the host and eliminated the infection in Mastomys coucha by a Th1/Th2 response including IgG2a antibody response. Whether F6 molecules become accessible to human host during natural course of infection and elicit similar response is not known. The present study was undertaken to determine the profile of IgG subclasses specifically reactive to F6 in different categories of bancroftian filariasis cases to infer any relationship between the levels of a particular F6-specific IgG subclass and the infection or disease status. Methods: Serum samples of normal individuals from filariasis non-endemic regions of India like Jammu & Kashmir, Uttarakhand, and Chandigarh [(NEN-W; n=10), healthy subjects from USA (NEN-U; n=10) and three categories of bancroftian filariasis cases from endemic areas: endemic normals (EN; n=10) with no symptoms and no microfilariae, asymptomatic microfilaremics (ASM; n=10) and chronic symptomatic amicrofilaremics (CL; n=10) were assayed for F6-specific IgG1, IgG2, IgG3 and IgG4 by ELISA using SDS-PAGE-isolated F6 fraction of B. malayi adult worms. Results: Significantly high levels of F6-specific IgG1, IgG2 and IgG3 were found in CL (P<0.001) and EN (P<0.01-0.001) bancroftian filariasis cases compared to NEN-U. Significant levels of F6-specific IgG1 (P<0.01) and IgG2 (P<0.01) but not IgG3 were found in ASM cases compared to NEN-U. The most abundant was IgG2 which when compared to NEN-U, was significantly high in CL (P<0.001) and EN cases (P<0.001), followed by ASM (P<0.01). F6-specific IgG4 response in EN, ASM and CL subjects was not significantly different from the levels of NEN-U. Among the non-endemic normals, the NEN-W subjects showed significant reactivity with IgG2 (P<0.001) but not with IgG1, IgG3 and IgG4 as compared to NEN-U subjects. IgG subclass levels were

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

    PubMed

    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. Effect of ferulic acid from Hibiscus mutabilis on filarial parasite Setaria cervi: molecular and biochemical approaches.

    PubMed

    Saini, Prasanta; Gayen, Prajna; Nayak, Ananya; Kumar, Deepak; Mukherjee, Niladri; Pal, Bikas C; Sinha Babu, Santi P

    2012-12-01

    In the reported work the in vitro activity of a methanolic extract of leaves of Hibiscus mutabilis (Malvaceae) against bovine Setaria cervi worms has been investigated. Bioassay-guided fractionation led to isolation of ferulic acid from ethyl acetate fraction. The crude extract and ferulic acid, the active molecule, showed significant microfilaricidal as well as macrofilaricidal activities against the microfilaria (L(1)) and adult of S. cervi by both a worm motility and MTT reduction assay. The findings thus provide a new lead for development of a filaricidal drug from natural products. To examine the possible mechanism of action of ferulic acid, the involvement of apoptosis in adult worms of S. cervi was investigated. We found extreme cellular disturbances in ferulic acid-treated adult worms characterized by chromatin condensation, in situ DNA fragmentation and nucleosomal DNA laddering. In this work we are reporting for the first time that ferulic acid exerts its antifilarial effect through induction of apoptosis and by downregulating and altering the level of some key antioxidants (GSH, GST and SOD) of the filarial nematode S. cervi. Our results have provided experimental evidence supporting that ferulic acid causes an increased proapoptotic gene expression and decreased expression of anti-apoptotic genes simultaneously with an elevated level of ROS and gradual dose dependent decline of parasitic GSH level. We also observed a gradual dose dependent elevation of GST and SOD activity in the ferulic acid treated worms.

  14. Brugia malayi microfilariae transport alphaviruses across the mosquito midgut

    PubMed Central

    Turell, Michael J.

    2017-01-01

    Concurrent ingestion of microfilariae (MF) and arboviruses by mosquitoes can enhance mosquito transmission of virus compared to when virus is ingested alone. Within hours of being ingested, MF penetrate the mosquito midgut and introduce virus into mosquito hemocoel, creating a disseminated viral infection much sooner than normal. How virus is actually introduced is not known. In this report, we present experimental evidence that suggests that certain alphaviruses may adhere or otherwise associate with sheathed Brugia malayi MF in the blood of a dually-infected host and that the virus is carried into the mosquito hemocoel by the MF during their penetration of the mosquito midgut. The mechanism of MF enhancement may be more complex than simple leakage of viremic blood into the hemocoel during MF penetration. The affinity of arboviruses to adhere to or otherwise associate with MF may depend on the specific combination of the virus and MF involved in a dual host infection. This in turn may determine the relative importance that MF enhancement has within an arbovirus transmission system. PMID:28222120

  15. Brugia malayi microfilariae transport alphaviruses across the mosquito midgut.

    PubMed

    Vaughan, Jefferson A; Turell, Michael J

    2017-01-01

    Concurrent ingestion of microfilariae (MF) and arboviruses by mosquitoes can enhance mosquito transmission of virus compared to when virus is ingested alone. Within hours of being ingested, MF penetrate the mosquito midgut and introduce virus into mosquito hemocoel, creating a disseminated viral infection much sooner than normal. How virus is actually introduced is not known. In this report, we present experimental evidence that suggests that certain alphaviruses may adhere or otherwise associate with sheathed Brugia malayi MF in the blood of a dually-infected host and that the virus is carried into the mosquito hemocoel by the MF during their penetration of the mosquito midgut. The mechanism of MF enhancement may be more complex than simple leakage of viremic blood into the hemocoel during MF penetration. The affinity of arboviruses to adhere to or otherwise associate with MF may depend on the specific combination of the virus and MF involved in a dual host infection. This in turn may determine the relative importance that MF enhancement has within an arbovirus transmission system.

  16. Infections of Brugia pahangi in conventional and nude (athymic) mice.

    PubMed

    Suswillo, R R; Owen, D G; Denham, D A

    1980-12-01

    AKR, BALB/c and CBA/Ca and T.O. mice were completely resistant to infection with third stage infective larvae of Brugia pahangi. Third, fourth and fifth stage worms transplanted from the peritoneal cavity of jirds into the peritoneal cavity of mice continued to develop. BALB/c mice were the most susceptible of the strains tested and adult worms were obtained after each type of transplanted infection. Congenitally athymic nude mice were much less resistant to transplanted worms and infective larvae developed to full maturity in most of them. Ten of 14 athymic mice infected by the intraperitoneal (ip) inoculation of infective larvae had microfilariae in their blood or peritoneal cavities. At autopsy a percentage recovery of adult worms of 0-38% (mean 11.1%) was obtained. Microfilariae were only found in the blood of 2 of 6 athymic mice infected by subcutaneous (sc) infection and at autopsy 0-19.1% (mean 6.1%) recoveries were obtained. The thymic littermates of the nudes were more resistant than those most of the other strains used.

  17. Spectral and landscape characterization of filarious and non-filarious villages in Egypt.

    PubMed

    Sowilem, Mohamed M; Bahgat, Iman M; el-Kady, Gamal A; el-Sawaf, Bahira M

    2006-08-01

    Filarial disease is endemic in Egypt in some villages of Nile Delta governorates where it is transmitted by Culex pipiens female. GIS functions are used to identify environmental indicators of high-risk village as indicated by mosquito density, human infection rate, vector species composition, mean life expectancy "e(o)" & environmental variables (geology, hydrology, soil types, etc) as well as meteorological factors (temperature, RH and rainfall) in relation to filaria transmission risk. Remote-sensing technology was used to distinguish between the two studied villages as high and non-infected, as defined by microfilarial prevalence. The results indicate that filaria transmission risk is higher at an area characterized by highly productive aquifers, silt clay soil, receiving little amount of rain with low relative humidity (RH). The results indicate that the most important landscape elements associated with prevalence are water and different vegetation. This work showed that the integration between GIS and remote sensing technologies to analyze and identify the environmental factors, associated with the disease, did not only allow mapping icurrent spatial patterns, but also predicting its distribution under expected future developmental and environmental changes.

  18. The identification of infective filarial larvae in Simuliidae*

    PubMed Central

    Nelson, G. S.; Pester, F. R. N.

    1962-01-01

    Although it is recognized that the presence of animal filariae can lead to confusion in the interpretation of infection rates in mosquito vectors of filariasis, the filariae found in man-biting simuliids are usually assumed to be Onchocerca volvulus. The authors of this paper emphasize that it is unwise to calculate transmission indices from infection rates in man-biting simuliids unless there is confidence in the identification of the filarial larvae. In this respect they cite their observations on Mount Elgon in Uganda which show that the majority of the filarial larvae in Simulium neavei—the local vector of onchocerciasis—are of species that do not affect man. To assist in the correct interpretation of infection rates in the vectors the authors made a detailed study of the morphological character of O. volvulus infective larvae and established criteria for distinguishing O. volvulus from other filariae known to be transmitted by simuliids. PMID:13938041

  19. The burden of non-filarial elephantiasis in Ethiopia.

    PubMed

    Animut, Abebe

    2007-12-01

    Although known for many years, non-filarial elephantiasis remains a public health problem in tropical Africa, including the farming community of Ethiopia. The problem may be exacerbated in women who shoulder most of the burden of agricultural labour in the countryside. The intention of this brief review is to emphasise the burden of the disease and to alert researchers and organisations concerned with health care and prevention.

  20. Prospects and challenges of CRISPR/Cas genome editing for the study and control of neglected vector-borne nematode diseases.

    PubMed

    Zamanian, Mostafa; Andersen, Erik C

    2016-09-01

    Neglected tropical diseases caused by parasitic nematodes inflict an immense health and socioeconomic burden throughout much of the developing world. Current estimates indicate that more than two billion people are infected with nematodes, resulting in the loss of 14 million disability-adjusted life years per annum. Although these parasites cause significant mortality, they primarily cause chronic morbidity through a wide range of severe clinical ailments. Treatment options for nematode infections are restricted to a small number of anthelmintic drugs, and the rapid expansion of anthelmintic mass drug administration raises concerns of drug resistance. Preservation of existing drugs is necessary, as well as the development of new treatment options and methods of control. We focus this review on how the democratization of CRISPR/Cas9 genome editing technology can be enlisted to improve our understanding of the biology of nematode parasites and our ability to treat the infections they cause. We will first explore how this robust method of genome manipulation can be used to newly exploit the powerful model nematode Caenorhabditis elegans for parasitology research. We will then discuss potential avenues to develop CRISPR/Cas9 editing protocols in filarial nematodes. Lastly, we will propose potential ways in which CRISPR/Cas9 can be used to engineer gene drives that target the transmission of mosquito-borne filarial nematodes. © 2016 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

  1. Human filarial Wolbachia lipopeptide directly activates human neutrophils in vitro

    PubMed Central

    Tamarozzi, F; Wright, H L; Johnston, K L; Edwards, S W; Turner, J D; Taylor, M J

    2014-01-01

    The host inflammatory response to the Onchocerca volvulus endosymbiont, Wolbachia, is a major contributing factor in the development of chronic pathology in humans (onchocerciasis/river blindness). Recently, the toll-like pattern recognition receptor motif of the major inflammatory ligands of filarial Wolbachia, membrane-associated diacylated lipoproteins, was functionally defined in murine models of pathology, including mediation of neutrophil recruitment to the cornea. However, the extent to which human neutrophils can be activated in response to this Wolbachia pattern recognition motif is not known. Therefore, the responses of purified peripheral blood human neutrophils to a synthetic N-terminal diacylated lipopeptide (WoLP) of filarial Wolbachia peptidoglycan-associated lipoprotein (PAL) were characterized. WoLP exposure led to a dose-dependent activation of healthy, human neutrophils that included gross morphological alterations and modulation of surface expressed integrins involved in tethering, rolling and extravasation. WoLP exposure induced chemotaxis but not chemokinesis of neutrophils, and secretion of the major neutrophil chemokine, interleukin 8. WoLP also induced and primed the respiratory burst, and enhanced neutrophil survival by delay of apoptosis. These results indicate that the major inflammatory motif of filarial Wolbachia lipoproteins directly activates human neutrophils in vitro and promotes a molecular pathway by which human neutrophils are recruited to sites of Onchocerca parasitism. PMID:24909063

  2. Human filarial Wolbachia lipopeptide directly activates human neutrophils in vitro.

    PubMed

    Tamarozzi, F; Wright, H L; Johnston, K L; Edwards, S W; Turner, J D; Taylor, M J

    2014-10-01

    The host inflammatory response to the Onchocerca volvulus endosymbiont, Wolbachia, is a major contributing factor in the development of chronic pathology in humans (onchocerciasis/river blindness). Recently, the toll-like pattern recognition receptor motif of the major inflammatory ligands of filarial Wolbachia, membrane-associated diacylated lipoproteins, was functionally defined in murine models of pathology, including mediation of neutrophil recruitment to the cornea. However, the extent to which human neutrophils can be activated in response to this Wolbachia pattern recognition motif is not known. Therefore, the responses of purified peripheral blood human neutrophils to a synthetic N-terminal diacylated lipopeptide (WoLP) of filarial Wolbachia peptidoglycan-associated lipoprotein (PAL) were characterized. WoLP exposure led to a dose-dependent activation of healthy, human neutrophils that included gross morphological alterations and modulation of surface expressed integrins involved in tethering, rolling and extravasation. WoLP exposure induced chemotaxis but not chemokinesis of neutrophils, and secretion of the major neutrophil chemokine, interleukin 8. WoLP also induced and primed the respiratory burst, and enhanced neutrophil survival by delay of apoptosis. These results indicate that the major inflammatory motif of filarial Wolbachia lipoproteins directly activates human neutrophils in vitro and promotes a molecular pathway by which human neutrophils are recruited to sites of Onchocerca parasitism. © 2014 The Authors. Parasite Immunology Published by John Wiley & Sons Ltd.

  3. Effect of gamma radiation on Brugia L3 development in vivo and the kinetics of granulomatous inflammation induced by these parasites.

    PubMed

    Nasarre, C; Rao, U R; Coleman, S U; Klei, T R

    1997-12-01

    Previous studies have shown that the downregulation of parasite-specific cellular immune response in Brugia-infected jirds requires viable worms but is not dependent on microfilariae (MF) for either induction or maintenance of this phenomenon. To clarify further which life cycle stages induce filarial hyporesponsiveness, jirds were infected intraperitoneally with third stage larvae (L3) exposed to 0, 15, 25, 35, 45, or 90 krad of gamma radiation to differentially alter L3 development. Necropsies were performed at 7, 14, 28, and 118 days postinoculation (DPI). The degree of parasite development, intraperitoneal inflammation, and pulmonary granulomatous inflammation (PGRN) to parasite antigen-coated beads embolized in the lungs were monitored at the time of necropsy. Parasite survival and worm lengths were inversely related to the irradiation dose. Gamma radiation at 35, 45, or 90 krad prevented larval molt to the adult stage. Some parasites irradiated with 15 or 25 krad developed beyond fourth stage larvae (L4) to infertile adult females. The PGRN peaked at 14 DPI in all infected groups. Downregulation of the PGRN occurred after 14 DPI in groups that received nonirradiated L3 or L3 irradiated with 15 krad. No significant decrease of the PGRN occurred in groups that received parasites irradiated with more than 15 krad. Significant peritoneal inflammation as indicated by an increase in macrophages occurred only in jirds that received nonirradiated L3. These data demonstrate the importance of the adult stages in inducing downmodulation in the absence of MF and suggest that the L4 may also play a role in the induction of this phenomenon. An alternate conclusion is that parasite burden and not developmental stage is important in the induction of this hyporesponsive state.

  4. Real-time PCR detection of the HhaI tandem DNA repeat in pre- and post-patent Brugia malayi infections: a study in Indonesian transmigrants

    PubMed Central

    2014-01-01

    Background Lymphatic filariasis caused by Wuchereria bancrofti or Brugia spp. is a public health problem in developing countries. To monitor bancroftian filariasis infections, Circulating Filarial Antigen (CFA) test is commonly used, but for brugian infections only microfilariae (Mf) microscopy and indirect IgG4 antibody analyses are available. Improved diagnostics for detecting latent infections are required. Methods An optimized real-time PCR targeting the brugian HhaI repeat was validated with plasma from microfilariae negative Mongolian gerbils (jirds) infected with B. malayi. Plasma samples from microfilaremic patients infected with B. malayi or W. bancrofti were used as positive and negative controls, respectively. PCR results of plasma samples from a transmigrant population in a B. malayi endemic area were compared to those of life-long residents in the same endemic area; and to IgG4 serology results from the same population. To discriminate between active infections and larval exposure a threshold was determined by correlation and Receiver-Operating Characteristics (ROC) curve analyses. Results The PCR detected HhaI in pre-patent (56 dpi) B. malayi infected jirds and B. malayi Mf-positive patients from Central Sulawesi, Indonesia. HhaI was also detected in 9/9 elephantiasis patients. In South Sulawesi 87.4% of the transmigrants and life-long residents (94% Mf-negative) were HhaI PCR positive. Based on ROC-curve analysis a threshold for active infections was set to >53 HhaI copies/μl (AUC: 0.854). Conclusions The results demonstrate that the HhaI PCR detects brugian infections with greater sensitivity than the IgG4 test, most notably in Mf-negative patients (i.e. pre-patent or latent infections). PMID:24685183

  5. Enzymes involved in the biogenesis of the nematode cuticle.

    PubMed

    Page, Antony P; Winter, Alan D

    2003-01-01

    Nematodes include species that are significant parasites of man, his domestic animals and crops, and cause chronic debilitating diseases in the developing world; such as lymphatic filariasis and river blindness caused by filarial species. Around one third of the World's population harbour parasitic nematodes; no vaccines exist for prevention of infection, limited effective drugs are available and drug resistance is an ever-increasing problem. A critical structure of the nematode is the protective cuticle, a collagen-rich extracellular matrix (ECM) that forms the exoskeleton, and is critical for viability. This resilient structure is synthesized sequentially five times during nematode development and offers protection from the environment, including the hosts' immune response. The detailed characterization of this complex structure; it's components, and the means by which they are synthesized, modified, processed and assembled will identify targets that may be exploited in the future control of parasitic nematodes. This review will focus on the nematode cuticle. This structure is predominantly composed of collagens, a class of proteins that are modified by a range of co- and post-translational modifications prior to assembly into higher order complexes or ECMs. The collagens and their associated enzymes have been comprehensively characterized in vertebrate systems and some of these studies will be addressed in this review. Conversely, the biosynthesis of this class of essential structural proteins has not been studied in such detail in the nematodes. As with all morphogenetic, functional and developmental studies in the Nematoda phylum, the free-living species Caenorhabditis elegans has proven to be invaluable in the characterization of the cuticle and the cuticle collagen gene family, and is now proving to be an excellent model in the study of cuticle collagen biosynthetic enzymes. This model system will be the main focus of this review.

  6. What does not kill them makes them stronger: larval environment and infectious dose alter mosquito potential to transmit filarial worms

    PubMed Central

    Breaux, Jennifer A.; Schumacher, Molly K.; Juliano, Steven A.

    2014-01-01

    For organisms with complex life cycles, larval environments can modify adult phenotypes. For mosquitoes and other vectors, when physiological impacts of stressors acting on larvae carry over into the adult stage they may interact with infectious dose of a vector-borne pathogen, producing a range of phenotypes for vector potential. Investigation of impacts of a common source of stress, larval crowding and intraspecific competition, on adult vector interactions with pathogens may increase our understanding of the dynamics of pathogen transmission by mosquito vectors. Using Aedes aegypti and the nematode parasite Brugia pahangi, we demonstrate dose dependency of fitness effects of B. pahangi infection on the mosquito, as well as interactions between competitive stress among larvae and infectious dose for resulting adults that affect the physiological and functional ability of mosquitoes to act as vectors. Contrary to results from studies on mosquito–arbovirus interactions, our results suggest that adults from crowded larvae may limit infection better than do adults from uncrowded controls, and that mosquitoes from high-quality larval environments are more physiologically and functionally capable vectors of B. pahangi. Our results provide another example of how the larval environment can have profound effects on vector potential of resulting adults. PMID:24827444

  7. What does not kill them makes them stronger: larval environment and infectious dose alter mosquito potential to transmit filarial worms.

    PubMed

    Breaux, Jennifer A; Schumacher, Molly K; Juliano, Steven A

    2014-07-07

    For organisms with complex life cycles, larval environments can modify adult phenotypes. For mosquitoes and other vectors, when physiological impacts of stressors acting on larvae carry over into the adult stage they may interact with infectious dose of a vector-borne pathogen, producing a range of phenotypes for vector potential. Investigation of impacts of a common source of stress, larval crowding and intraspecific competition, on adult vector interactions with pathogens may increase our understanding of the dynamics of pathogen transmission by mosquito vectors. Using Aedes aegypti and the nematode parasite Brugia pahangi, we demonstrate dose dependency of fitness effects of B. pahangi infection on the mosquito, as well as interactions between competitive stress among larvae and infectious dose for resulting adults that affect the physiological and functional ability of mosquitoes to act as vectors. Contrary to results from studies on mosquito-arbovirus interactions, our results suggest that adults from crowded larvae may limit infection better than do adults from uncrowded controls, and that mosquitoes from high-quality larval environments are more physiologically and functionally capable vectors of B. pahangi. Our results provide another example of how the larval environment can have profound effects on vector potential of resulting adults.

  8. Identification of a molecular marker for genotyping human lymphatic filarial nematode parasite Wuchereria bancrofti.

    PubMed

    Patra, K P; Ramu, Thangadurai; Hoti, S L; Pragasam, G Siva; Das, P K

    2007-05-01

    In India, Mass Drug Administration is on going towards elimination of lymphatic filariasis in many areas, which might lead to intense selection pressure on the parasite populations and their genetic restructuring. This calls for molecular finger printing of Wuchereria bancrofti parasite populations at national level and monitoring genetic changes in the future. For this purpose a reliable, less expensive, rapid, and reproducible molecular tool is necessary, which is not available for W. bancrofti at this time. We identified robust molecular markers based on the comparison of random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) profiles and the genetic data generated from parasite populations collected from areas in Northern (Varanasi, Uttar Pradesh state), Southern (Kozhikode, Kerala State) and Central regions (Jagdalpur, Chattisgarh state) of India, where lymphatic filariasis is endemic for many decades. RAPD profiles for these parasite populations were generated using three different primers and the dendrograms constructed using the profiles were all different. In order to identify appropriate RAPD primer(s), we compared the results of RAPD with the fingerprint profile and genetic data obtained by the more reliable AFLP technique, using the parasite populations from the same areas. RAPD marker (OP8) primer produced phylogenetic data almost similar to that of AFLP analysis. The marker was able to reveal variations between the parasite populations collected from Varanasi, Kozhikode, and Jagdalpur. Most importantly, RAPD primer OP8 produced reproducible results, when tested in three different trials. In view of the limited availability of W. bancrofti parasite DNA, along with a lower cost and ease of performance, RAPD appears to be more suitable compared to AFLP at the present juncture, since complete genome information of this parasite is still not available. Thus, RAPD primer OP8 can be a very useful molecular maker for DNA finger printing of W. bancrofti populations at present.

  9. The occurrence of the filarial nematode Dirofilaria repens in canine hosts from Maio Island, Cape Verde.

    PubMed

    Marcos, R; Pereira, C; Maia, J P; Santos, M; Luzzago, C; Lauzi, S; Genchi, C; Faustino, A; Puente-Payo, P

    2017-01-01

    The prevalence of canine Dirofilaria infection in Maio Island (Cape Verde) was analysed by serology, morphological and molecular identification of the parasite species. Blood and sera were collected from 150 dogs and 80 cats aged over 6 months from various localities of the island. DNA was extracted from blood and samples were screened by polymerase chain reaction (PCR) using microfilaria-specific primers. No Dirofilaria immitis was found in dogs while D. repens microfilariae were found in 5.3% of dogs and 6% were positive by PCR. The species identity was confirmed by sequencing of PCR products, which showed almost 100% homology with D. repens European sequences published in GenBank. No difference in Dirofilaria infection was observed between males and females or in dogs with different weights. However, older dogs and those from the western part of Maio Island were more frequently infected. No Dirofilaria was found in cats. This study represents the first evidence of D. repens in Cape Verde (West Africa) and highlights the need for implementing control measures and for a better surveillance of dirofilariosis in Africa.

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

    PubMed Central

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

    2014-01-01

    In mammalian systems RNA can move between cells via vesicles. Here we demonstrate that the gastrointestinal nematode Heligmosomoides polygyrus, which infects mice, secretes vesicles containing microRNAs (miRNAs) and Y RNAs as well as a nematode Argonaute protein. These vesicles are of intestinal origin and are enriched for homologues of mammalian exosome proteins. Administration of the nematode exosomes to mice suppresses Type 2 innate responses and eosinophilia induced by the allergen Alternaria. Microarray analysis of mouse cells incubated with nematode exosomes in vitro identifies Il33r and Dusp1 as suppressed genes, and Dusp1 can be repressed by nematode miRNAs based on a reporter assay. We further identify miRNAs from the filarial nematode Litomosoides sigmodontis in the serum of infected mice, suggesting that miRNA secretion into host tissues is conserved among parasitic nematodes. These results reveal exosomes as another mechanism by which helminths manipulate their hosts and provide a mechanistic framework for RNA transfer between animal species. PMID:25421927

  11. Nematodes (Rhabditida: Steinernematidae and Heterorhabditidae)

    USDA-ARS?s Scientific Manuscript database

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

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

    PubMed

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

    2013-09-01

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

  13. The Caenorhabditis globin gene family reveals extensive nematode-specific radiation and diversification

    PubMed Central

    2008-01-01

    Background Globin isoforms with variant properties and functions have been found in the pseudocoel, body wall and cuticle of various nematode species and even in the eyespots of the insect-parasite Mermis nigrescens. In fact, much higher levels of complexity exist, as shown by recent whole genome analysis studies. In silico analysis of the genome of Caenorhabditis elegans revealed an unexpectedly high number of globin genes featuring a remarkable diversity in gene structure, amino acid sequence and expression profiles. Results In the present study we have analyzed whole genomic data from C. briggsae, C. remanei, Pristionchus pacificus and Brugia malayi and EST data from several other nematode species to study the evolutionary history of the nematode globin gene family. We find a high level of conservation of the C. elegans globin complement, with even distantly related nematodes harboring orthologs to many Caenorhabditis globins. Bayesian phylogenetic analysis resolves all nematode globins into two distinct globin classes. Analysis of the globin intron-exon structures suggests extensive loss of ancestral introns and gain of new positions in deep nematode ancestors, and mainly loss in the Caenorhabditis lineage. We also show that the Caenorhabditis globin genes are expressed in distinct, mostly non-overlapping, sets of cells and that they are all under strong purifying selection. Conclusion Our results enable reconstruction of the evolutionary history of the globin gene family in the nematode phylum. A duplication of an ancestral globin gene occurred before the divergence of the Platyhelminthes and the Nematoda and one of the duplicated genes radiated further in the nematode phylum before the split of the Spirurina and Rhabditina and was followed by further radiation in the lineage leading to Caenorhabditis. The resulting globin genes were subject to processes of subfunctionalization and diversification leading to cell-specific expression patterns. Strong purifying

  14. The Caenorhabditis globin gene family reveals extensive nematode-specific radiation and diversification.

    PubMed

    Hoogewijs, David; De Henau, Sasha; Dewilde, Sylvia; Moens, Luc; Couvreur, Marjolein; Borgonie, Gaetan; Vinogradov, Serge N; Roy, Scott W; Vanfleteren, Jacques R

    2008-10-09

    Globin isoforms with variant properties and functions have been found in the pseudocoel, body wall and cuticle of various nematode species and even in the eyespots of the insect-parasite Mermis nigrescens. In fact, much higher levels of complexity exist, as shown by recent whole genome analysis studies. In silico analysis of the genome of Caenorhabditis elegans revealed an unexpectedly high number of globin genes featuring a remarkable diversity in gene structure, amino acid sequence and expression profiles. In the present study we have analyzed whole genomic data from C. briggsae, C. remanei, Pristionchus pacificus and Brugia malayi and EST data from several other nematode species to study the evolutionary history of the nematode globin gene family. We find a high level of conservation of the C. elegans globin complement, with even distantly related nematodes harboring orthologs to many Caenorhabditis globins. Bayesian phylogenetic analysis resolves all nematode globins into two distinct globin classes. Analysis of the globin intron-exon structures suggests extensive loss of ancestral introns and gain of new positions in deep nematode ancestors, and mainly loss in the Caenorhabditis lineage. We also show that the Caenorhabditis globin genes are expressed in distinct, mostly non-overlapping, sets of cells and that they are all under strong purifying selection. Our results enable reconstruction of the evolutionary history of the globin gene family in the nematode phylum. A duplication of an ancestral globin gene occurred before the divergence of the Platyhelminthes and the Nematoda and one of the duplicated genes radiated further in the nematode phylum before the split of the Spirurina and Rhabditina and was followed by further radiation in the lineage leading to Caenorhabditis. The resulting globin genes were subject to processes of subfunctionalization and diversification leading to cell-specific expression patterns. Strong purifying selection subsequently

  15. Neutropenic Mice Provide Insight into the Role of Skin-Infiltrating Neutrophils in the Host Protective Immunity against Filarial Infective Larvae.

    PubMed

    Pionnier, Nicolas; Brotin, Emilie; Karadjian, Gregory; Hemon, Patrice; Gaudin-Nomé, Françoise; Vallarino-Lhermitte, Nathaly; Nieguitsila, Adélaïde; Fercoq, Frédéric; Aknin, Marie-Laure; Marin-Esteban, Viviana; Chollet-Martin, Sylvie; Schlecht-Louf, Géraldine; Bachelerie, Françoise; Martin, Coralie

    2016-04-01

    Our knowledge and control of the pathogenesis induced by the filariae remain limited due to experimental obstacles presented by parasitic nematode biology and the lack of selective prophylactic or curative drugs. Here we thought to investigate the role of neutrophils in the host innate immune response to the infection caused by the Litomosoides sigmodontis murine model of human filariasis using mice harboring a gain-of-function mutation of the chemokine receptor CXCR4 and characterized by a profound blood neutropenia (Cxcr4(+/1013)). We provided manifold evidence emphasizing the major role of neutrophils in the control of the early stages of infection occurring in the skin. Firstly, we uncovered that the filarial parasitic success was dramatically decreased in Cxcr4(+/1013) mice upon subcutaneous delivery of the infective stages of filariae (infective larvae, L3). This protection was linked to a larger number of neutrophils constitutively present in the skin of the mutant mice herein characterized as compared to wild type (wt) mice. Indeed, the parasitic success in Cxcr4(+/1013) mice was normalized either upon depleting neutrophils, including the pool in the skin, or bypassing the skin via the intravenous infection of L3. Second, extending these observations to wt mice we found that subcutaneous delivery of L3 elicited an increase of neutrophils in the skin. Finally, living L3 larvae were able to promote in both wt and mutant mice, an oxidative burst response and the release of neutrophil extracellular traps (NET). This response of neutrophils, which is adapted to the large size of the L3 infective stages, likely directly contributes to the anti-parasitic strategies implemented by the host. Collectively, our results are demonstrating the contribution of neutrophils in early anti-filarial host responses through their capacity to undertake different anti-filarial strategies such as oxidative burst, degranulation and NETosis.

  16. Neutropenic Mice Provide Insight into the Role of Skin-Infiltrating Neutrophils in the Host Protective Immunity against Filarial Infective Larvae

    PubMed Central

    Pionnier, Nicolas; Brotin, Emilie; Karadjian, Gregory; Hemon, Patrice; Gaudin-Nomé, Françoise; Vallarino-Lhermitte, Nathaly; Nieguitsila, Adélaïde; Fercoq, Frédéric; Aknin, Marie-Laure; Marin-Esteban, Viviana; Chollet-Martin, Sylvie; Schlecht-Louf, Géraldine

    2016-01-01

    Our knowledge and control of the pathogenesis induced by the filariae remain limited due to experimental obstacles presented by parasitic nematode biology and the lack of selective prophylactic or curative drugs. Here we thought to investigate the role of neutrophils in the host innate immune response to the infection caused by the Litomosoides sigmodontis murine model of human filariasis using mice harboring a gain-of-function mutation of the chemokine receptor CXCR4 and characterized by a profound blood neutropenia (Cxcr4+/1013). We provided manifold evidence emphasizing the major role of neutrophils in the control of the early stages of infection occurring in the skin. Firstly, we uncovered that the filarial parasitic success was dramatically decreased in Cxcr4+/1013 mice upon subcutaneous delivery of the infective stages of filariae (infective larvae, L3). This protection was linked to a larger number of neutrophils constitutively present in the skin of the mutant mice herein characterized as compared to wild type (wt) mice. Indeed, the parasitic success in Cxcr4+/1013 mice was normalized either upon depleting neutrophils, including the pool in the skin, or bypassing the skin via the intravenous infection of L3. Second, extending these observations to wt mice we found that subcutaneous delivery of L3 elicited an increase of neutrophils in the skin. Finally, living L3 larvae were able to promote in both wt and mutant mice, an oxidative burst response and the release of neutrophil extracellular traps (NET). This response of neutrophils, which is adapted to the large size of the L3 infective stages, likely directly contributes to the anti-parasitic strategies implemented by the host. Collectively, our results are demonstrating the contribution of neutrophils in early anti-filarial host responses through their capacity to undertake different anti-filarial strategies such as oxidative burst, degranulation and NETosis. PMID:27111140

  17. Interleukin 1 (IL-1)- and IL-23-mediated expansion of filarial antigen-specific Th17 and Th22 cells in filarial lymphedema.

    PubMed

    Anuradha, R; George, P Jovvian; Chandrasekaran, V; Kumaran, P Paul; Nutman, Thomas B; Babu, Subash

    2014-07-01

    Lymphatic filarial disease is known to be associated with elevated Th1 responses and normal or diminished Th2 responses to parasite-specific antigens. The roles of Th17 cells and the recently described Th22 cells have not been examined in detail in either filarial infection itself or in filarial disease (e.g., lymphedema and elephantiasis). To explore the roles of Th17 and Th22 cells and their subsets, we examined the frequencies of these cells in individuals with filarial lymphedema (chronic pathology [CP]), in clinically asymptomatic infected (INF) individuals, and in uninfected (UN) individuals ex vivo and in response to parasite and nonparasite antigens. Those with disease (CP) had significantly expanded frequencies of Th17 and Th22 cells, compared with either INF or UN individuals, at baseline (ex vivo) and in response to parasite antigens. This antigen-driven expansion of Th17 and Th22 cells was dependent on interleukin 1 (IL-1), IL-23, and, to lesser extent, transforming growth factor β (TGF-β), as blockade of any of these cytokines resulted in significantly diminished frequencies of Th17 and Th22 cells. Our findings, therefore, suggest that filarial parasite-driven expansion of Th17 and Th22 cells is associated with the pathogenesis of filarial infections and disease. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Interleukin 1 (IL-1)- and IL-23-Mediated Expansion of Filarial Antigen-Specific Th17 and Th22 Cells in Filarial Lymphedema

    PubMed Central

    Anuradha, R.; George, P. Jovvian; Chandrasekaran, V.; Kumaran, P. Paul; Nutman, Thomas B.

    2014-01-01

    Lymphatic filarial disease is known to be associated with elevated Th1 responses and normal or diminished Th2 responses to parasite-specific antigens. The roles of Th17 cells and the recently described Th22 cells have not been examined in detail in either filarial infection itself or in filarial disease (e.g., lymphedema and elephantiasis). To explore the roles of Th17 and Th22 cells and their subsets, we examined the frequencies of these cells in individuals with filarial lymphedema (chronic pathology [CP]), in clinically asymptomatic infected (INF) individuals, and in uninfected (UN) individuals ex vivo and in response to parasite and nonparasite antigens. Those with disease (CP) had significantly expanded frequencies of Th17 and Th22 cells, compared with either INF or UN individuals, at baseline (ex vivo) and in response to parasite antigens. This antigen-driven expansion of Th17 and Th22 cells was dependent on interleukin 1 (IL-1), IL-23, and, to lesser extent, transforming growth factor β (TGF-β), as blockade of any of these cytokines resulted in significantly diminished frequencies of Th17 and Th22 cells. Our findings, therefore, suggest that filarial parasite-driven expansion of Th17 and Th22 cells is associated with the pathogenesis of filarial infections and disease. PMID:24807054

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

    PubMed

    Gondorf, Fabian; Berbudi, Afiat; Buerfent, Benedikt C; Ajendra, Jesuthas; Bloemker, Dominique; Specht, Sabine; Schmidt, David; Neumann, Anna-Lena; Layland, Laura E; Hoerauf, Achim; Hübner, Marc P

    2015-01-01

    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, but may also

  20. Migratory phase of Litomosoides sigmodontis filarial infective larvae is associated with pathology and transient increase of S100A9 expressing neutrophils in the lung

    PubMed Central

    Pionnier, Nicolas; Vallarino-Lhermitte, Nathaly; Lefoulon, Emilie; Nieguitsila, Adélaïde; Specht, Sabine; Carlin, Leo M.; Martin, Coralie

    2017-01-01

    Filarial infections are tropical diseases caused by nematodes of the Onchocercidae family such as Mansonella perstans. The infective larvae (L3) are transmitted into the skin of vertebrate hosts by blood-feeding vectors. Many filarial species settle in the serous cavities including M. perstans in humans and L. sigmodontis, a well-established model of filariasis in mice. L. sigmodontis L3 migrate to the pleural cavity where they moult into L4 around day 9 and into male and female adult worms around day 30. Little is known of the early phase of the parasite life cycle, after the L3 is inoculated in the dermis by the vector and enters the afferent lymphatic vessels and before the moulting processes in the pleural cavity. Here we reveal a pulmonary phase associated with lung damage characterized by haemorrhages and granulomas suggesting L3 reach the lung via pulmonary capillaries and damage the endothelium and parenchyma by crossing them to enter the pleural cavity. This study also provides evidence for a transient inflammation in the lung characterized by a very early recruitment of neutrophils associated with high expression levels of S100A8 and S100A9 proteins. PMID:28486498

  1. STUDIES ON THE METABOLISM OF THE FILARIAL WORM, LITOMOSOIDES CARINII

    PubMed Central

    Bueding, Ernest

    1949-01-01

    The filarial worm, Litomosoides carinii, has a high rate of aerobic and anaerobic glucose metabolism. Aerobically 30 to 45 per cent of the glucose utilized was converted to lactic acid, 25 to 35 per cent to acetic acid, and 10 to 20 per cent to a polysaccharide. Anaerobically over 80 per cent of the total carbohydrate removed by the filariae was metabolized to lactic acid, the remainder was accounted for by the production of acetic acid. The high rates of aerobic and anaerobic lactic acid production and of aerobic polysaccharide synthesis, as well as the absence of a postanaerobic increase of the oxygen uptake, differentiate the filarial worm, L. carinii, from the known metabolic characteristics of all other helminths and of most other invertebrates. The rate of aerobic lactate and pyruvate utilization by the filariae appears to be much slower than that of glucose. Anaerobically, dismutation of two moles of pyruvate to one mole of lactate, one mole of acetate, and one mole of CO2, occurred. Aerobically, acetate production from pyruvate exceeded that of lactate. A significant proportion of the pyruvate metabolized aerobically by the filariae was not oxidized to acetate. In the presence of fluoroacetate, aerobic incubation of the filariae in a glucose-containing medium produced a marked decrease in the respiration of the organisms, an accumulation of pyruvate, a decreased formation of acetate, and an increase in aerobic glycolysis. Low concentrations of fluoroacetate (1 x 10–3 M) inhibited the oxidative metabolism of pyruvate which did not result in the conversion of pyruvate to acetate; higher concentrations of this inhibitor produced also a decreased oxidation of pyruvate to acetate. No evidence has been obtained that fluoroacetate inhibits the respiration of the filariae because of a competitive inhibition of acetate oxidation. Respiration and glycolysis of filariae were markedly decreased by low concentrations of p-chloromercuric benzoate. This inhibition could

  2. Vector and reservoir host of a case of human Brugia pahangi infection in Selangor, peninsular Malaysia.

    PubMed

    Muslim, A; Fong, M Y; Mahmud, R; Sivanandam, S

    2013-12-01

    A case of human eye infection caused by Brugia pahangi was reported in 2010 in a semi rural village in Selangor, peninsular Malaysia. Our report here reveals results of investigation on the vector and animal host for the transmission of the infection. We conducted entomological survey and cat blood examination in the vicinity of the patient's home. The mosquito species Armigeres subalbatus was incriminated as the vector, whereas cat served as the reservoir host.

  3. Midgut Barrier Imparts Selective Resistance to Filarial Worm Infection in Culex pipiens pipiens

    PubMed Central

    Michalski, Michelle L.; Erickson, Sara M.; Bartholomay, Lyric C.; Christensen, Bruce M.

    2010-01-01

    Mosquitoes in the Culex pipiens complex thrive in temperate and tropical regions worldwide, and serve as efficient vectors of Bancroftian lymphatic filariasis (LF) caused by Wuchereria bancrofti in Asia, Africa, the West Indies, South America, and Micronesia. However, members of this mosquito complex do not act as natural vectors for Brugian LF caused by Brugia malayi, or for the cat parasite B. pahangi, despite their presence in South Asia where these parasites are endemic. Previous work with the Iowa strain of Culex pipiens pipiens demonstrates that it is equally susceptible to W. bancrofti as is the natural Cx. p. pipiens vector in the Nile Delta, however it is refractory to infection with Brugia spp. Here we report that the infectivity barrier for Brugia spp. in Cx. p. pipiens is the mosquito midgut, which inflicts internal and lethal damage to ingested microfilariae. Following per os Brugia exposures, the prevalence of infection is significantly lower in Cx. p. pipiens compared to susceptible mosquito controls, and differs between parasite species with <50% and <5% of Cx. p. pipiens becoming infected with B. pahangi and B. malayi, respectively. When Brugia spp. mf were inoculated intrathoracically to bypass the midgut, larvae developed equally well as in controls, indicating that, beyond the midgut, Cx. p. pipiens is physiologically compatible with Brugia spp. Mf isolated from Cx. p. pipiens midguts exhibited compromised motility, and unlike mf derived from blood or isolated from the midguts of Ae. aegypti, failed to develop when inoculated intrathoracically into susceptible mosquitoes. Together these data strongly support the role of the midgut as the primary infection barrier for Brugia spp. in Cx. p. pipiens. Examination of parasites recovered from the Cx. p. pipiens midgut by vital staining, and those exsheathed with papain, suggest that the damage inflicted by the midgut is subcuticular and disrupts internal tissues. Microscopic studies of these worms

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

    PubMed Central

    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

  5. Podoconiosis - non-filarial geochemical elephantiasis - a neglected tropical disease?

    PubMed

    Nenoff, Pietro; Simon, Jan Christoph; Muylowa, Grace K; Davey, Gail

    2010-01-01

    Podoconiosis or mossy foot is a form of non-filarial lymphedema. This geochemical elephantiasis is a disabling condition caused by the passage of microparticles of silica and aluminum silicates through the skin of people walking barefoot in areas with a high content of soil of volcanic origin. Podoconiosis is widespread in tropical Africa, Central America and North India, yet it remains a neglected and under-researched condition. The disabling effects of podoconiosis cause great hardship to patients. It adversely affects the economic (reduced productivity and absenteeism), social (marriage, education, etc.) and psychological (social stigma) well-being of those affected. Podoconiosis can be prevented; the main primary preventive measure is protective footwear. Secondary measures include a strict hygiene regimen and compression therapy, which can reverse initial lesions. Tertiary approaches include surgical management, such as shaving operations to reduce hyperplastic and verrucous elephantiasis.

  6. Entomopathogenic nematodes and insect management

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes (genera Heterorhabditis, Steinernema, and Neosteinernema) are used as bioinsecticides. The nematodes are ubiquitous and have been isolated in soil of every continent except Antarctica. The nematodes kill insects through a mutualism with a bacterium (Photorhabdus spp. or ...

  7. Physicochemical properties of the modeled structure of astacin metalloprotease moulting enzyme NAS-36 and mapping the druggable allosteric space of Heamonchus contortus, Brugia malayi and Ceanorhabditis elegans via molecular dynamics simulation.

    PubMed

    Sharma, Om Prakash; Agrawal, Sonali; Kumar, M Suresh

    2013-12-01

    Nematodes represent the second largest phylum in the animal kingdom. It is the most abundant species (500,000) in the planet. It causes chronic, debilitating infections worldwide such as ascariasis, trichuriasis, hookworm, enterobiasis, strongyloidiasis, filariasis and trichinosis, among others. Molecular modeling tools can play an important role in the identification and structural investigation of molecular targets that can act as a vital candidate against filariasis. In this study, sequence analysis of NAS-36 from H. contortus (Heamonchus contortus), B. malayi (Brugia malayi) and C. elegans (Ceanorhabditis elegans) has been performed, in order to identify the conserved residues. Tertiary structure was developed for an insight into the molecular structure of the enzyme. Molecular Dynamics Simulation (MDS) studies have been carried out to analyze the stability and the physical properties of the proposed enzyme models in the H. contortus, B. malayi and C. elegans. Moreover, the drug binding sites have been mapped for inhibiting the function of NAS-36 enzyme. The molecular identity of this protease could eventually demonstrate how ex-sheathment is regulated, as well as provide a potential target of anthelmintics for the prevention of nematode infections.

  8. Vaccination of Gerbils with Bm-103 and Bm-RAL-2 Concurrently or as a Fusion Protein Confers Consistent and Improved Protection against Brugia malayi Infection.

    PubMed

    Arumugam, Sridhar; Wei, Junfei; Liu, Zhuyun; Abraham, David; Bell, Aaron; Bottazzi, Maria Elena; Hotez, Peter J; Zhan, Bin; Lustigman, Sara; Klei, Thomas R

    2016-04-01

    The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and Bm-RAL-2, with worm reduction of 61% and 56% at 90 dpi. Vaccination with Bm-103 and Bm-RAL-2 as a fusion protein or concurrently not only induced a significant worm reduction of 61% and 42%, respectively, at 150 dpi, but also significantly reduced the fecundity of female worms as determined by embryograms. Elevated levels of antigen-specific IgG were observed in all vaccinated gerbils. Serum from gerbils vaccinated with Bm-103 and Bm-RAL-2 individually, concurrently or as a fusion protein killed third stage larvae in vitro when combined with peritoneal exudate cells. Although vaccination with Bm-103 and Bm-RAL-2 individually conferred protection against B. malayi infection in gerbils, a more consistent and enhanced protection was induced by vaccination with Bm-103 and Bm-RAL-2 fusion protein and when they were used concurrently. Further characterization and optimization of these filarial vaccines are warranted.

  9. Vaccination of Gerbils with Bm-103 and Bm-RAL-2 Concurrently or as a Fusion Protein Confers Consistent and Improved Protection against Brugia malayi Infection

    PubMed Central

    Arumugam, Sridhar; Wei, Junfei; Liu, Zhuyun; Abraham, David; Bell, Aaron; Bottazzi, Maria Elena; Hotez, Peter J.; Zhan, Bin; Lustigman, Sara; Klei, Thomas R.

    2016-01-01

    Background The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. Methodology and Principle Findings Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and Bm-RAL-2, with worm reduction of 61% and 56% at 90 dpi. Vaccination with Bm-103 and Bm-RAL-2 as a fusion protein or concurrently not only induced a significant worm reduction of 61% and 42%, respectively, at 150 dpi, but also significantly reduced the fecundity of female worms as determined by embryograms. Elevated levels of antigen-specific IgG were observed in all vaccinated gerbils. Serum from gerbils vaccinated with Bm-103 and Bm-RAL-2 individually, concurrently or as a fusion protein killed third stage larvae in vitro when combined with peritoneal exudate cells. Conclusion Although vaccination with Bm-103 and Bm-RAL-2 individually conferred protection against B. malayi infection in gerbils, a more consistent and enhanced protection was induced by vaccination with Bm-103 and Bm-RAL-2 fusion protein and when they were used concurrently. Further characterization and optimization of these filarial vaccines are warranted. PMID:27045170

  10. Immunogenicity and Protective Efficacy of Brugia malayi Heavy Chain Myosin as Homologous DNA, Protein and Heterologous DNA/Protein Prime Boost Vaccine in Rodent Model

    PubMed Central

    Gupta, Jyoti; Pathak, Manisha; Misra, Sweta; Misra-Bhattacharya, Shailja

    2015-01-01

    We earlier demonstrated the immunoprophylactic efficacy of recombinant heavy chain myosin (Bm-Myo) of Brugia malayi (B. malayi) in rodent models. In the current study, further attempts have been made to improve this efficacy by employing alternate approaches such as homologous DNA (pcD-Myo) and heterologous DNA/protein prime boost (pcD-Myo+Bm-Myo) in BALB/c mouse model. The gene bm-myo was cloned in a mammalian expression vector pcDNA 3.1(+) and protein expression was confirmed in mammalian Vero cell line. A significant degree of protection (79.2%±2.32) against L3 challenge in pcD-Myo+Bm-Myo immunized group was observed which was much higher than that exerted by Bm-Myo (66.6%±2.23) and pcD-Myo (41.6%±2.45). In the heterologous immunized group, the percentage of peritoneal leukocytes such as macrophages, neutrophils, B cells and T cells marginally increased and their population augmented further significantly following L3 challenge. pcD-Myo+Bm-Myo immunization elicited robust cellular and humoral immune responses as compared to pcD-Myo and Bm-Myo groups as evidenced by an increased accumulation of CD4+, CD8+ T cells and CD19+ B cells in the mouse spleen and activation of peritoneal macrophages. Though immunized animals produced antigen-specific IgG antibodies and isotypes, sera of mice receiving pcD-Myo+Bm-Myo or Bm-Myo developed much higher antibody levels than other groups and there was profound antibody-dependent cellular adhesion and cytotoxicity (ADCC) to B. malayi infective larvae (L3). pcD-Myo+Bm-Myo as well as Bm-Myo mice generated a mixed T helper cell phenotype as evidenced by the production of both pro-inflammatory (IL-2, IFN-γ) and anti-inflammatory (IL-4, IL-10) cytokines. Mice receiving pcD-Myo on contrary displayed a polarized pro-inflammatory immune response. The findings suggest that the priming of animals with DNA followed by protein booster generates heightened and mixed pro- and anti-inflammatory immune responses that are capable of providing

  11. nGASP – the nematode genome annotation assessment project

    PubMed Central

    Coghlan, Avril; Fiedler, Tristan J; McKay, Sheldon J; Flicek, Paul; Harris, Todd W; Blasiar, Darin; Stein, Lincoln D

    2008-01-01

    Background 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 across 10 Mb of the C. elegans genome. Predictions were compared to reference gene sets consisting of confirmed or manually curated gene models from WormBase. Results 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. 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 reported for combiners in the human genome. C. elegans genes with exons of unusual hexamer content, as well as those with unusually many exons, short exons, long introns, a weak translation start signal, weak splice sites, or poorly conserved orthologs posed the greatest difficulty for gene-finders. Conclusion This experiment establishes a baseline of gene prediction accuracy in Caenorhabditis genomes, and has guided the choice of gene-finders for the annotation of newly sequenced genomes of Caenorhabditis and other nematode species. We have created new gene sets for C. briggsae, C. remanei, C. brenneri, C. japonica, and Brugia malayi using some of the best-performing gene-finders. PMID:19099578

  12. The Nematode Caenorhabditis Elegans.

    ERIC Educational Resources Information Center

    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)

  13. Nematode nervous systems.

    PubMed

    Schafer, William

    2016-10-24

    Nematodes comprise one of the largest phyla in the animal kingdom, both in terms of individual numbers and species diversity. Although only 20,000-30,000 species have been described, it is estimated that the true number ranges between 100,000 and 10 million. Marine, freshwater, and terrestrial species are all widespread, and some nematodes have even been isolated from such inhospitable environments as deserts, hot springs, and polar seas. Some nematode species are parasitic, with either plant or animal hosts; other species are free-living microbivores, scavengers, or predators of insects or other nematodes. Nematodes vary widely in size, from small microbivores that grow no larger than 100 μm to large animal parasites growing to several meters in length. They adopt a variety of reproductive strategies: most species are gonochoristic (i.e., have male and female sexes), but self-fertile hermaphroditic species are not uncommon, and parthenogenetic species are also known. Nematodes belong to the superphylum Ecdysozoa, a clade of moulting animals that also includes arthropods, tardigrades and priapulids. Although nematode fossils are rare, the origin of the nematode phylum is believed to be very ancient, with the divergence from arthropods estimated based on molecular data to have been between 900 and 1,300 Ma.

  14. The Nematode Caenorhabditis Elegans.

    ERIC Educational Resources Information Center

    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)

  15. Nematode-Trapping Fungi.

    PubMed

    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.

  16. Susceptibility of Anopheles quadrimaculatus (Diptera: Culicidae) to subperiodic Brugia malayi and Brugia pahangi (Nematoda: Filarioidea) adapted to nude mice and jirds.

    PubMed

    Nayar, J K; Knight, J W; Vickery, A C

    1990-05-01

    Anopheles quadrimaculatus and Aedes aegypti (Black-eyed Liverpool strain) were fed on jirds and nude mice (jird-jird infection, jird-mouse infection, and mouse-jird infection) infected with subperiodic Brugia malayi and B. pahangi. Microfilariae of B. malayi from jird-mouse and mouse-jird infections developed normally in An. quadrimaculatus, whereas those from jird-jird infections did not develop. Microfilariae of both species from jirds and nude mice developed normally in Ae. aegypti and those of B. pahangi developed normally in An. quadrimaculatus. It is suggested that microfilariae from nude mice are modified physiologically, immunologically, or both so that they can develop in refractory An. quadrimaculatus, thus indicating that susceptibility and refractoriness of An. quadrimaculatus to B. malayi also is influenced by factors relating to the vertebrate host in addition to mosquito genetic factors.

  17. Diethylcarbamazine-mediated clearance of Brugia pahangi microfilariae in immunodeficient nude mice.

    PubMed

    Vickery, A C; Nayar, J K; Tamplin, M L

    1985-05-01

    Congenitally athymic nude C3H/HeN mice, microfilaremic with Brugia pahangi, were treated with diethylcarbamazine citrate (DEC). A single oral dose (100 mg/Kg body weight) of DEC resulted in the rapid reduction of numbers of circulating microfilariae in nude, thymus-grafted nude and complement-depleted nude mice. Antibodies of the IgM and IgG isotypes were not detected in the serum of microfilaremic nudes or on the microfilarial surface. These results suggest that DEC-mediated clearance of microfilariae from the circulation of nude mice is probably independent of thymus-dependent immunological mechanisms.

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

    PubMed Central

    Ward, Jordan D.

    2015-01-01

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

  19. Toward molecular parasitologic diagnosis: enhanced diagnostic sensitivity for filarial infections in mobile populations.

    PubMed

    Fink, Doran L; Fahle, Gary A; Fischer, Steven; Fedorko, Daniel F; Nutman, Thomas B

    2011-01-01

    The diagnosis of filarial infections among individuals residing in areas where the disease is not endemic requires both strong clinical suspicion and expert training in infrequently practiced parasitological methods. Recently developed filarial molecular diagnostic assays are highly sensitive and specific but have limited availability and have not been closely evaluated for clinical use outside populations residing in areas of endemicity. In this study, we assessed the performance of a panel of real-time PCR assays for the four most common human filarial pathogens among blood and tissue samples collected from a cohort of patients undergoing evaluation for suspected filarial infections. Compared to blood filtration, real-time PCR was equally sensitive for the detection of microfilaremia due to Wuchereria bancrofti (2 of 46 samples positive by both blood filtration and PCR with no discordant results) and Loa loa (24 of 208 samples positive by both blood filtration and PCR, 4 samples positive by PCR only, and 3 samples positive by blood filtration only). Real-time PCR of skin snip samples was significantly more sensitive than microscopic examination for the detection of Onchocerca volvulus microfiladermia (2 of 218 samples positive by both microscopy and PCR and 12 samples positive by PCR only). The molecular assays required smaller amounts of blood and tissue than conventional methods and could be performed by laboratory personnel without specialized parasitology training. Taken together, these data demonstrate the utility of the molecular diagnosis of filarial infections in mobile populations.

  20. Toward Molecular Parasitologic Diagnosis: Enhanced Diagnostic Sensitivity for Filarial Infections in Mobile Populations▿

    PubMed Central

    Fink, Doran L.; Fahle, Gary A.; Fischer, Steven; Fedorko, Daniel F.; Nutman, Thomas B.

    2011-01-01

    The diagnosis of filarial infections among individuals residing in areas where the disease is not endemic requires both strong clinical suspicion and expert training in infrequently practiced parasitological methods. Recently developed filarial molecular diagnostic assays are highly sensitive and specific but have limited availability and have not been closely evaluated for clinical use outside populations residing in areas of endemicity. In this study, we assessed the performance of a panel of real-time PCR assays for the four most common human filarial pathogens among blood and tissue samples collected from a cohort of patients undergoing evaluation for suspected filarial infections. Compared to blood filtration, real-time PCR was equally sensitive for the detection of microfilaremia due to Wuchereria bancrofti (2 of 46 samples positive by both blood filtration and PCR with no discordant results) and Loa loa (24 of 208 samples positive by both blood filtration and PCR, 4 samples positive by PCR only, and 3 samples positive by blood filtration only). Real-time PCR of skin snip samples was significantly more sensitive than microscopic examination for the detection of Onchocerca volvulus microfiladermia (2 of 218 samples positive by both microscopy and PCR and 12 samples positive by PCR only). The molecular assays required smaller amounts of blood and tissue than conventional methods and could be performed by laboratory personnel without specialized parasitology training. Taken together, these data demonstrate the utility of the molecular diagnosis of filarial infections in mobile populations. PMID:20980560

  1. Use of fractionated urinary filarial antigen in the diagnosis of human filariasis.

    PubMed

    Ramaprasad, P; Harinath, B C

    1995-02-01

    Fractionated urinary filarial antigen UFA C2 has shown high antigenic activity after absorption of urinary albumin present in the fraction. As little as 500 ag (10(-18) g) of albumin absorbed UFA C2, labelled as UFA C2-A, was found to be sufficient to detect filarial antibody. Stick enzyme immunoassay to assess the immunodiagnostic potential of UFA C2-A indicated filarial IgG antibody in 89% of microfilaraemic (mf) cases, 84% of clinical filariasis and 7% of endemic normals. UFA C2-A was found to be present in circulation in active as well as clinical infections as observed by inhibition assay using UFA C2-A penicillinase conjugate. Eighty-six per cent of mf, 50% of clinical cases and 6% of endemic normal subjects revealed parasite antigen to UFA C2-A on further serological analysis. None of the non-endemic normal sera showed the presence of filarial antibody/antigen to UFA C2-A. Furthermore, the test to determine phosphorylcholine (PC) bearing epitopes in UFA C2-A indicated no immunological reaction with anti-PC monoclonal antibody by avidin-biotin enzyme linked immunosorbent assay (ELISA). The highly sensitive and more easily obtainable non-PC urinary filarial antigen, UFA C2-A, is of great immunodiagnostic interest for lymphatic filariasis.

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

    PubMed

    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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27417080

  4. A novel small heat shock protein 12.6 (HSP12.6) from Brugia malayi functions as a human IL-10 receptor binding protein.

    PubMed

    Gnanasekar, Munirathinam; Anandharaman, Veerapathran; Anand, Setty Balakrishnan; Nutman, Thomas B; Ramaswamy, Kalyanasundaram

    2008-06-01

    Phage display cDNA expression library of the third stage larvae (L3) of Brugia malayi was screened for identifying target(s) that bound to the human interleukin-10 receptor (huIL10R). This iterative screening identified an insert that showed significant homology to Caenorhabditis elegans HSP12.6. The gene was designated B. malayi HSP12.6 (BmHSP12.6) and has orthologues in several gastrointestinal nematode genome (Ancylostoma caninum, Ascaris lumbricoides and Ascaris suum) but the gene or gene product has not been studied further in these parasites. Structural analyses of BmHSP12.6 showed that it has a highly conserved alpha-crystallin central domain that is characteristic of other small heat shock proteins (HSPs). BmHSP12.6 has a short N-terminal domain and an unusually small C-terminal domain flanking the crystallin domain suggesting that this protein belongs to a novel class of small HSPs. BmHSP12.6 appears to be differentially transcribed with highest expression in the vertebrate stages of the parasite (L4, adult and mf) compared to its mosquito vector stage (L3). More importantly recombinant BmHSP12.6 bound to huIL10R in a dose dependent fashion and inhibited the binding of human IL-10 (huIL10) to huIL10R in vitro. rBmHSP12.6 also enhanced the growth and proliferation of MC/9 mast cells in vitro similar to huIL10. This study thus describes a novel small HSP from B. malayi that has the capacity to bind to huIL10R, block binding of huIL10 to huIL10R and function similar to huIL10.

  5. The "filarial dance" is not characteristic of filariasis: observations of "dancing megasperm" on high-resolution sonography in patients from nonendemic areas mimicking the filarial dance and a proposed mechanism for this phenomenon.

    PubMed

    Adejolu, Margaret; Sidhu, Paul S

    2011-08-01

    The objective of this series was to show that the sonographic appearance described as the "filarial dance" is not characteristic of filariasis but occurs in nonendemic areas as a manifestation of epididymal obstruction. An experienced observer documented cases after initial observation of the filarial dance in routine clinical practice using high-frequency linear array transducers. The filarial dance was described as excessive to-and-fro movement of echogenic particles within a prominent epididymis and graded 1 to 4 according to the extent and distribution of the abnormality. The country of birth, exposure to filarial infection or travel to a filarial-endemic area, previous scrotal surgery including vasectomy, any previous or current scrotal inflammatory disease, and any congenital testicular abnormalities were recorded. Over a 10-year period, sonographic appearances consistent with the filarial dance were observed in 18 patients (bilateral in 6). The mean patient age was 47.7 (range, 28-91) years. The abnormality was graded in the 24 affected testes as follows: grade 1, n = 3; grade 2, n = 8; grade 3, n = 8; and grade 4, n = 5. No patient had a history of filariasis or travel to an endemic area. Six of 18 patients (33.3%) had bilateral vasectomies; 5 (27.8%) had a history of epididymo-orchitis in the ipsilateral testis; 3 (16.7%) had previous scrotal surgery; and 4 (22.2%) had no relevant urologic history. We have described a sonographic appearance identical to the filarial dance in men with no history of filarial infection. Most had previous scrotal surgery or infection, suggesting that the filarial dance may not always be due to movement of filarial worms. The unifying condition in patients with filariasis and our patients is lymphatic obstruction, likely the underlying cause of the appearance in both groups.

  6. Entomopathogenic nematode application technology

    USDA-ARS?s Scientific Manuscript database

    Biocontrol success when using entomopathogenic nematodes (EPNs) in the genera Heterorhabditis and Steinernema relies on a variety of factors including components of the application event itself. Successful application encompasses both abiotic and biotic influences. For example, adverse array of equi...

  7. Formulation of Nematodes.

    PubMed

    Peters, Arne

    2016-01-01

    The enduring stages of entomopathogenic nematodes of the genera Steinernema and Heterorhabditis are infective juveniles, which require a high humidity and sufficient ventilation for survival. Formulations must account for these requirements. Nematodes may be formulated inside the insects in which they reproduced or they need to be cleaned and mixed with a suitable binder to maintain humidity but allowing for gas exchange. Another method for formulation is the encapsulation in beads of Ca-alginate. Generic procedures for these formulation techniques are described.

  8. Neuroparasitic infections: nematodes.

    PubMed

    Walker, M D; Zunt, J R

    2005-09-01

    Globalization has produced an increase in the number of people at risk for contracting parasitic infection. Central nervous system infection by nematodal parasites can be devastating. Early recognition and treatment of infection can significantly decrease morbidity of the parasitic infection, as well as the risk of secondary superinfection. The clinical presentation, diagnosis, and treatment for five of the more common nematodal infections of the nervous system--Angiostrongylus spp., Baylisacaris procyonis, Gnathostoma spinigerum, Strongyloides stercoralis, and Toxocara spp.--is reviewed.

  9. C-cinnamoyl glycosides as a new class of anti-filarial agents.

    PubMed

    Roy, Priya; Dhara, Debashis; Parida, Pravat Kumar; Kar, Rajiv Kumar; Bhunia, Anirban; Jana, Kuladip; Sinha Babu, Santi P; Misra, Anup Kumar

    2016-05-23

    A series of C-cinnamoyl glycosides has been synthesized in good yield by the BF3·OEt2 catalyzed aldol condensation of C-glycosylated acetone derivative with a variety of aromatic aldehydes. The synthesized compounds were evaluated for their potential as anti-filarial agents against bovine filarial parasite Setaria cervi and human filariid Wuchereria bancrofti using a number of biological assays such as relative movability (RM) assessment and MTT reduction assay. Among twenty seven test compounds six compounds were found active in terms of MIC, IC50 and LC50 values. Further biological studies were carried out using three lead compounds because of their significantly low MIC values and IC50 values compared to the standard anti-filarial drug Ivermectin. In addition, structure activity relationship study of the test compounds has been carried out using 3D-QSAR analysis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

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

    PubMed

    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.

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

    PubMed Central

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

    2016-01-01

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

  12. Comparative results of non-operative multi-modal therapy for filarial lymphoedema

    PubMed Central

    Gogia, S. B.; Appavoo, N. C.; Mohan, A.; Kumar, M. Burney

    2009-01-01

    A comparative analysis of different conservative modes of therapy for lymphoedema, largely of Filarial origin, was conducted in a trial therapy unit in Chengalpattu, a Filarial endemic district in Tamil Nadu. Results were compared using a single chambered intermittent pneumatic compression pump, heat therapy, and interferential therapy machines. The results showed improvement of limb size between 20% and 60% of possible reduction (where 100% would mean return of limb circumference to the same as that of the normal side). Pneumatic compression therapy, when used alone, showed the best results, which were significantly better than all others whether alone or in combination. PMID:19881016

  13. Filarial abscess: Aspiration of adult gravid female worm from submandibular region, an unusual presentation.

    PubMed

    Afrose, Ruquiya; Alam, Mohammad Feroz; Ahmad, Syed Shamshad; Naim, Mohammed

    2017-01-01

    Microfilaria is a major public health problem in tropical and subtropical countries and is an endemic problem in India. Wuchereria bancrofti is the most common filarial infection. In some cases, microfilariae and adult filarial worm have been incidentally detected in fine-needle aspirates of various lesions; detection of microfilaria from subcutaneous site or from abscess site is even rarer. We here report an unusual case of Bancroftian microfilariasis in a 68-year-old female coming from endemic area presenting with right submandibular abscess. Our aim is to highlight the chances of finding microfilaria and adult worm in cytology of an unsuspected case at an unusual site.

  14. Filarial abscess: Aspiration of adult gravid female worm from submandibular region, an unusual presentation

    PubMed Central

    Afrose, Ruquiya; Alam, Mohammad Feroz; Ahmad, Syed Shamshad; Naim, Mohammed

    2017-01-01

    Microfilaria is a major public health problem in tropical and subtropical countries and is an endemic problem in India. Wuchereria bancrofti is the most common filarial infection. In some cases, microfilariae and adult filarial worm have been incidentally detected in fine-needle aspirates of various lesions; detection of microfilaria from subcutaneous site or from abscess site is even rarer. We here report an unusual case of Bancroftian microfilariasis in a 68-year-old female coming from endemic area presenting with right submandibular abscess. Our aim is to highlight the chances of finding microfilaria and adult worm in cytology of an unsuspected case at an unusual site. PMID:28182103

  15. Roles of Steroids in Nematodes

    USDA-ARS?s Scientific Manuscript database

    The inability of nematodes to biosynthesize steroids de novo and the resulting dependence of parasitic nematodes upon their hosts have enhanced the importance of elucidating the metabolism of sterols and the hormonal and other functions of steroids in nematodes. Biochemical research has revealed th...

  16. Nematode-borne plant viruses

    USDA-ARS?s Scientific Manuscript database

    There are 30 plant-parasitic nematode species that are known to transmit 14 plant viruses. Nematode-transmitted viruses affect a range of agriculturally important crops including grape, cherry, potato, and tomato. The nematodes that transmit viruses are found in two families, Longidoridae and Tric...

  17. Evolution of lymph thrombi in experimental Brugia malayi infections: a scanning electron microscopic study.

    PubMed

    Fader, R C; Ewert, A

    1986-12-01

    Lymph thrombi in cats experimentally-infected with Brugia malayi were examined by scanning electron microscopy. A variety of morphological forms were noted and it appeared that thrombi undergo a maturation process characterized by at least three transitional phases. Initially, the thrombus consists of erythrocytes encased in fibrin (Phase I). Phase II thrombi are characterized by the appearance of phagocytic cells and fibroblasts on the surface of the thrombus. At the end of the maturation process, the thrombus surface consists solely of fibroblasts or endothelial cells, perhaps derived from the vessel wall (Phase III). Occlusion of the lymphatic lumen by thrombi and the accompanying inflammatory response triggered by B. malayi infection may be a major factor in the pathogenesis of lymph stasis in this disorder.

  18. Successful Treatment of Brugia pahangi in Naturally Infected Cats with Ivermectin

    PubMed Central

    Chungpivat, Sudchit

    2013-01-01

    Lymphatic filariasis is a common parasitic disease of cats in tropical regions including Thailand. The objective of this study was to determine the efficacy of ivermectin against microfilariae of Brugia pahangi in naturally infected cats. Eight cats naturally infected with B. pahangi were divided into control (untreated) and treated groups. Cats in the latter group were given ivermectin injection at 400 µg/kg weekly for 2 months. Microfilariae were counted every week until 48 weeks. Microfilaremia was significantly decreased in the treated group 4 weeks after starting the treatment and become zero at week 9 and afterwards. On the other hand, cats in the control group had high microfilaremia throughout the study. It was successful to treat and control B. pahangi infection in naturally infected cats using ivermectin. PMID:24516287

  19. Nematode cholinergic pharmacology

    SciTech Connect

    Segerberg, M.A.

    1989-01-01

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

  20. Comparative genomics of nematodes.

    PubMed

    Mitreva, Makedonka; Blaxter, Mark L; Bird, David M; McCarter, James P

    2005-10-01

    Recent transcriptome and genome projects have dramatically expanded the biological data available across the phylum Nematoda. Here we summarize analyses of these sequences, which have revealed multiple unexpected results. Despite a uniform body plan, nematodes are more diverse at the molecular level than was previously recognized, with many species- and group-specific novel genes. In the genus Caenorhabditis, changes in chromosome arrangement, particularly local inversions, are also rapid, with breakpoints occurring at 50-fold the rate in vertebrates. Tylenchid plant parasitic nematode genomes contain several genes closely related to genes in bacteria, implicating horizontal gene transfer events in the origins of plant parasitism. Functional genomics techniques are also moving from Caenorhabditis elegans to application throughout the phylum. Soon, eight more draft nematode genome sequences will be available. This unique resource will underpin both molecular understanding of these most abundant metazoan organisms and aid in the examination of the dynamics of genome evolution in animals.

  1. Elephantiasis of non-filarial origin (podoconiosis) in the highlands of north-western Cameroon.

    PubMed

    Wanji, S; Tendongfor, N; Esum, M; Che, J N; Mand, S; Tanga Mbi, C; Enyong, P; Hoerauf, A

    2008-09-01

    Lymphoedema, a condition of localized fluid retention, results from a compromised lymphatic system. Although one common cause in the tropics is infection with filarial worms, non-filarial lymphoedema, also known as podoconiosis, has been reported among barefoot farmers in volcanic highland zones of Africa, Central and South America and north-western India. There are conflicting reports on the causes of lymphoedema in the highland regions of Cameroon, where the condition is of great public-health importance. To characterise the focus of lymphoedema in the highlands of the North West province of Cameroon and investigate its real causes, a cross-sectional study was carried out on the adults (aged > or =15 years) living in the communities that fall within the Ndop and Tubah health districts. The subjects, who had to have lived in the study area for at least 10 years, were interviewed, examined clinically, and, when possible, checked for microfilaraemia. The cases of lymphoedema confirmed by ultrasonography and a random sample of the other subjects were also tested for filarial antigenaemia. The interviews, which explored knowledge, attitudes and perceptions (KAP) relating to lymphoedema, revealed that the condition was well known, with each study community having a local name for it. Of the 834 individuals examined clinically, 66 (8.1%) had lymphoedema of the lower limb, with all the clinical stages of this condition represented. None of the 792 individuals examined parasitologically, however, had microfilariae of W. bancrofti (or any other filarial parasite) in their peripheral blood, and only one (0.25%) of the 399 individuals tested for the circulating antigens of W. bancrofti gave a positive result. In addition, none of the 504 mosquitoes caught landing on human bait in the study area and dissected was found to harbour any stage of W. bancrofti. These findings indicate that the elephantiasis seen in the North West province of Cameroon is of non-filarial origin.

  2. Inhibition of Cathepsin B by E-64 Induces Oxidative Stress and Apoptosis in Filarial Parasite

    PubMed Central

    Wadhawan, Mohit; Singh, Neetu; Rathaur, Sushma

    2014-01-01

    Background 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. Methods and Findings 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. Conclusion 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

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

    PubMed Central

    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

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

    PubMed

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

    2017-03-24

    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.

  5. Signaling between nematodes and plants.

    PubMed

    Bird, David McK

    2004-08-01

    After hatching in the soil, root-knot nematodes must locate and penetrate a root, migrate into the vascular cylinder, and establish a permanent feeding site. Presumably, these events are accompanied by extensive signaling between the nematode parasite and the host. Hence, much emphasis has been placed on identifying proteins that are secreted by the nematode during the migratory phase. Further progress in understanding the signaling events has been made recently by studying the host response. Striking parallels can be drawn between the nematode-plant interaction and plant symbioses with other microorganisms, and evidence is emerging to suggest that nematodes acquired components of their parasitic armory from those microbes.

  6. Role of horizontal gene transfer in the evolution of plant parasitism among nematodes.

    PubMed

    Mitreva, Makedonka; Smant, Geert; Helder, Johannes

    2009-01-01

    Horizontal gene transfer (HGT) implies the non-sexual exchange of genetic material between species - in some cases even across kingdoms. Although common among Bacteria and Archaea, HGTs from pro- to eukaryotes and between eukaryotes were thought to be extremely rare. Recent studies on intracellular bacteria and their hosts seriously question this view. Recipient organisms could benefit from HGT as new gene packages could allow them to broaden or change their diet, colonize new habitats, or survive conditions that previously would have been lethal.About a decade ago, plant parasitic nematodes were shown to produce and secrete cellulases. Prior to this, animals were thought to fully depend on microbial symbionts for the breakdown of plant cell walls. This discovery prompted Keen and Roberts (1) to hypothesize that the ability of nematodes to parasitize plants was acquired by HGT from soil bacteria to (ancestral) bacterivorous nematodes. Since the identification of the first nematode cellulases, many more plant cell wall-degrading enzymes (CWDE) have been identified in a range of plant parasitic nematode species.Here we discuss a number of criteria that can be used to underpin an HGT claim. HGT requires close physical contact between donor and recipient, and this could be achieved in, for example, a symbiont-host, or a trophic relationship. The former type of relationship was indeed shown to potentially result in the transfer of genetic material (e.g., Brugia malayi and Wolbachia). However, currently known endosymbionts of nematodes may not be the source of CWDEs. Remarkably, all cellulases discovered so far within the order Tylenchida belong to a single glycoside hydrolase family (GHF5). A range of soil bacteria harbours GHF5 cellulases, but of course nothing can be said about the gene content of soil bacteria at the time HGT took place (if at all). We suggest that characterisation of cellulases (and other CWDEs) and their genomic organisation in more basal

  7. Brugia malayi infective larvae fail to activate Langerhans cells and dermal dendritic cells in human skin.

    PubMed

    Cotton, R N; McDonald-Fleming, R; Boyd, A; Spates, K; Nutman, T B; Tolouei Semnani, R

    2015-02-01

    Filarial infection in humans is initiated when a mosquito deposits third-stage parasite larvae (L3) in the skin. Langerhans cells (LCs) and dermal dendritic cells (DDCs) are the first cells that the parasite encounters, and L3s must evade these highly effective antigen-presenting cells to establish infection. To assess LC and DDC responses to L3 in human skin, we employed three models of increasing physiologic relevance: in vitro-generated LCs, epidermal blister explants and full-thickness human skin sections. In vitro-generated LCs expressed TLR1-10 and robustly produced IL-6 and TNF-α in response to PolyI:C, but pre-exposure to L3s did not alter inflammatory cytokine production or TLR expression. L3s did not modulate expression of LC markers CDH1, CD207, or CD1a, or the regulatory products TSLP or IDO in epidermal explants or in vitro-generated LC. LC, CD14+ DDC, CD1c+ DC and CD141+ DC from human skin sections were analysed by flow cytometry. While PolyI:C potently induced CCL22 production in LC, CD1c+ DC, and CD141+ DC, and IL-10 production in LC, L3s did not modulate the numbers of or cytokine production by any skin DC subset. L3s broadly failed to activate or modulate LCs or DDCs, suggesting filarial larvae expertly evade APC detection in human skin.

  8. How nematode sperm crawl.

    PubMed

    Bottino, Dean; Mogilner, Alexander; Roberts, Tom; Stewart, Murray; Oster, George

    2002-01-15

    Sperm of the nematode, Ascaris suum, crawl using lamellipodial protrusion, adhesion and retraction, a process analogous to the amoeboid motility of other eukaryotic cells. However, rather than employing an actin cytoskeleton to generate locomotion, nematode sperm use the major sperm protein (MSP). Moreover, nematode sperm lack detectable molecular motors or the battery of actin-binding proteins that characterize actin-based motility. The Ascaris system provides a simple 'stripped down' version of a crawling cell in which to examine the basic mechanism of cell locomotion independently of other cellular functions that involve the cytoskeleton. Here we present a mechanochemical analysis of crawling in Ascaris sperm. We construct a finite element model wherein (a) localized filament polymerization and bundling generate the force for lamellipodial extension and (b) energy stored in the gel formed from the filament bundles at the leading edge is subsequently used to produce the contraction that pulls the rear of the cell forward. The model reproduces the major features of crawling sperm and provides a framework in which amoeboid cell motility can be analyzed. Although the model refers primarily to the locomotion of nematode sperm, it has important implications for the mechanics of actin-based cell motility.

  9. Nematode management in pecans

    USDA-ARS?s Scientific Manuscript database

    In 2002, the pecan root-knot nematode (Meloidogyne partityla = PRKN) was found on pecan in the southeastern U.S. and was associated with stressed trees exhibiting dead branches in the upper canopy and (or) typical mouse ear (ME) associated foliar symptoms. This research evaluates the host susceptib...

  10. Requirement of lipid II biosynthesis for cell division in cell wall-less Wolbachia, endobacteria of arthropods and filarial nematodes.

    PubMed

    Vollmer, Jennifer; Schiefer, Andrea; Schneider, Tanja; Jülicher, Karen; Johnston, Kelly L; Taylor, Mark J; Sahl, Hans-Georg; Hoerauf, Achim; Pfarr, Kenneth

    2013-04-01

    Obligate Wolbachia endobacteria have a reduced genome and retained genes are hypothesized to be crucial for survival. Although intracellular bacteria do not need a stress-bearing peptidoglycan cell wall, Wolbachia encode proteins necessary to synthesize the peptidoglycan precursor lipid II. The activity of the enzymes catalyzing the last two steps of this pathway was previously shown, and Wolbachia are sensitive to inhibition of lipid II synthesis. A puzzling characteristic of Wolbachia is the lack of genes for l-amino acid racemases essential for lipid II synthesis. Transcription analysis showed the expression of a possible alternative racemase metC, and recombinant Wolbachia MetC indeed had racemase activity that may substitute for the absent l-Ala racemase. However, enzymes needed to form mature peptidoglycan are absent and the function of Wolbachia lipid II is unknown. Inhibition of lipid II biosynthesis resulted in enlargement of Wolbachia cells and redistribution of Wolbachia peptidoglycan-associated lipoprotein, demonstrating that lipid II is required for coordinated cell division and may interact with the lipoprotein. We conclude that lipid II is essential for Wolbachia cell division and that this function is potentially conserved in the Gram-negative bacteria. Copyright © 2013 Elsevier GmbH. All rights reserved.

  11. Phylum-Level Conservation of Regulatory Information in Nematodes despite Extensive Non-coding Sequence Divergence

    PubMed Central

    Gordon, Kacy L.; Arthur, Robert K.; Ruvinsky, Ilya

    2015-01-01

    Gene regulatory information guides development and shapes the course of evolution. To test conservation of gene regulation within the phylum Nematoda, we compared the functions of putative cis-regulatory sequences of four sets of orthologs (unc-47, unc-25, mec-3 and elt-2) from distantly-related nematode species. These species, Caenorhabditis elegans, its congeneric C. briggsae, and three parasitic species Meloidogyne hapla, Brugia malayi, and Trichinella spiralis, represent four of the five major clades in the phylum Nematoda. Despite the great phylogenetic distances sampled and the extensive sequence divergence of nematode genomes, all but one of the regulatory elements we tested are able to drive at least a subset of the expected gene expression patterns. We show that functionally conserved cis-regulatory elements have no more extended sequence similarity to their C. elegans orthologs than would be expected by chance, but they do harbor motifs that are important for proper expression of the C. elegans genes. These motifs are too short to be distinguished from the background level of sequence similarity, and while identical in sequence they are not conserved in orientation or position. Functional tests reveal that some of these motifs contribute to proper expression. Our results suggest that conserved regulatory circuitry can persist despite considerable turnover within cis elements. PMID:26020930

  12. Phylum-Level Conservation of Regulatory Information in Nematodes despite Extensive Non-coding Sequence Divergence.

    PubMed

    Gordon, Kacy L; Arthur, Robert K; Ruvinsky, Ilya

    2015-05-01

    Gene regulatory information guides development and shapes the course of evolution. To test conservation of gene regulation within the phylum Nematoda, we compared the functions of putative cis-regulatory sequences of four sets of orthologs (unc-47, unc-25, mec-3 and elt-2) from distantly-related nematode species. These species, Caenorhabditis elegans, its congeneric C. briggsae, and three parasitic species Meloidogyne hapla, Brugia malayi, and Trichinella spiralis, represent four of the five major clades in the phylum Nematoda. Despite the great phylogenetic distances sampled and the extensive sequence divergence of nematode genomes, all but one of the regulatory elements we tested are able to drive at least a subset of the expected gene expression patterns. We show that functionally conserved cis-regulatory elements have no more extended sequence similarity to their C. elegans orthologs than would be expected by chance, but they do harbor motifs that are important for proper expression of the C. elegans genes. These motifs are too short to be distinguished from the background level of sequence similarity, and while identical in sequence they are not conserved in orientation or position. Functional tests reveal that some of these motifs contribute to proper expression. Our results suggest that conserved regulatory circuitry can persist despite considerable turnover within cis elements.

  13. Horizontal gene transfer of microbial cellulases into nematode genomes is associated with functional assimilation and gene turnover

    PubMed Central

    2011-01-01

    Background Natural acquisition of novel genes from other organisms by horizontal or lateral gene transfer is well established for microorganisms. There is now growing evidence that horizontal gene transfer also plays important roles in the evolution of eukaryotes. Genome-sequencing and EST projects of plant and animal associated nematodes such as Brugia, Meloidogyne, Bursaphelenchus and Pristionchus indicate horizontal gene transfer as a key adaptation towards parasitism and pathogenicity. However, little is known about the functional activity and evolutionary longevity of genes acquired by horizontal gene transfer and the mechanisms favoring such processes. Results We examine the transfer of cellulase genes to the free-living and beetle-associated nematode Pristionchus pacificus, for which detailed phylogenetic knowledge is available, to address predictions by evolutionary theory for successful gene transfer. We used transcriptomics in seven Pristionchus species and three other related diplogastrid nematodes with a well-defined phylogenetic framework to study the evolution of ancestral cellulase genes acquired by horizontal gene transfer. We performed intra-species, inter-species and inter-genic analysis by comparing the transcriptomes of these ten species and tested for cellulase activity in each species. Species with cellulase genes in their transcriptome always exhibited cellulase activity indicating functional integration into the host's genome and biology. The phylogenetic profile of cellulase genes was congruent with the species phylogeny demonstrating gene longevity. Cellulase genes show notable turnover with elevated birth and death rates. Comparison by sequencing of three selected cellulase genes in 24 natural isolates of Pristionchus pacificus suggests these high evolutionary dynamics to be associated with copy number variations and positive selection. Conclusion We could demonstrate functional integration of acquired cellulase genes into the nematode

  14. [Trophic types of the nematodes].

    PubMed

    Kornobis, Franciszek Wojciech

    2008-01-01

    The aim of the article is to present trophic types (i.e non-systematic groups feeding on the same kind of food) of the nematodes. Seven trophic types (covering all known species) are described: (1) microbivores (nematodes feeding on unicellular microorganisms) with two examples: C. elegans and the nematodes of two families: Steinernematidae and Heterorhabditidae, (2) parasites of Vertebrates, (3) parasites of Invertebrates with example of the family Acugutturidae, (4) parasites of plants with two examples: Tylenchorhynchus dubius and Heterodera schachtii, (5) parasites of fungi, (6) predatory nematodes, (7) omnivores (nematodes feeding on different kinds of food). Basic information on the anatomy of the alimentary canal and feeding behaviour of the nematodes are also provided.

  15. Soil Nematodes in Terrestrial Ecosystems

    PubMed Central

    Yeates, G. W.

    1979-01-01

    There has been much work on plant-feeding nematodes, and less on other soil nematodes, their distribution, abundance, intrinsic properties, and interactions with biotic and abiotic factors. Seasonal variation in nematode fauna as a whole is correlated with factors such as moisture, temperature, and plant growth; at each site nematode distribution generally reflects root distribution. There is a positive correlation between average nematode abundance and primary production as controlled by moisture, temperature, nutrients, etc. Soil nematodes, whether bacterial feeders, fungivores, plant feeders, omnivores, or predators, all influence the populations of the organisms they feed on. Although soil trematodes probably contribute less than 1% to soil respiration they may play an important role in nutrient cycling in the soil through their influence on bacterial growth and plant nutrient availability. PMID:19300638

  16. Chemotherapeutic reactions of Chandlerella hawkingi, the filarial parasite of the Indian jungle crow, Corvus macrorhynchos (Agler).

    PubMed

    Chatterjee, R J; Sen, A B

    1969-02-01

    1. A high percentage of Indian jungle crows (Corvus macrorhynchos Wagler), found in and around Lucknow, harbour a natural filarial infection Chandlerella hawkingi. The microfilariae of this species are sheathed and show nocturnal periodicity.2. Fourteen compounds active against other kinds of filariae, especially against Litomosoides carinii, were tested against Ch. hawkingi in jungle crows to find whether this infection would be suitable for routine filarial chemotherapy. This is apparently the first report of systematic screening of antifilarial compounds against an avian filariasis.3. Tartar emetic (10 mg/kg intravenously, daily for 6 days) and arsenamide (5 mg/kg intraperitoneally, daily for 6 days) proved to be effective in killing adult worms. Trivalent tryparsamide, though effective, was toxic in the doses tried. Diethylcarbamazine and other compounds tested were ineffective.4. The chemotherapeutic susceptibilities of Ch. hawkingi differ considerably from those of L. carinii and Wuchereria bancrofti.

  17. Chemotherapeutic reactions of Chandlerella hawkingi, the filarial parasite of the Indian jungle crow, Corvus macrorhynchos (Wagler)

    PubMed Central

    Chatterjee, R. K.; Sen, A. B.

    1969-01-01

    1. A high percentage of Indian jungle crows (Corvus macrorhynchos Wagler), found in and around Lucknow, harbour a natural filarial infection Chandlerella hawkingi. The microfilariae of this species are sheathed and show nocturnal periodicity. 2. Fourteen compounds active against other kinds of filariae, especially against Litomosoides carinii, were tested against Ch. hawkingi in jungle crows to find whether this infection would be suitable for routine filarial chemotherapy. This is apparently the first report of systematic screening of antifilarial compounds against an avian filariasis. 3. Tartar emetic (10 mg/kg intravenously, daily for 6 days) and arsenamide (5 mg/kg intraperitoneally, daily for 6 days) proved to be effective in killing adult worms. Trivalent tryparsamide, though effective, was toxic in the doses tried. Diethylcarbamazine and other compounds tested were ineffective. 4. The chemotherapeutic susceptibilities of Ch. hawkingi differ considerably from those of L. carinii and Wuchereria bancrofti. PMID:5774047

  18. The Potentials and Pitfalls of Microarrays in Neglected Tropical Diseases: A Focus on Human Filarial Infections

    PubMed Central

    Kwarteng, Alexander; Ahuno, Samuel Terkper

    2016-01-01

    Data obtained from expression microarrays enables deeper understanding of the molecular signatures of infectious diseases. It provides rapid and accurate information on how infections affect the clustering of gene expression profiles, pathways and networks that are transcriptionally active during various infection states compared to conventional diagnostic methods, which primarily focus on single genes or proteins. Thus, microarray technologies offer advantages in understanding host-parasite interactions associated with filarial infections. More importantly, the use of these technologies can aid diagnostics and helps translate current genomic research into effective treatment and interventions for filarial infections. Studying immune responses via microarray following infection can yield insight into genetic pathways and networks that can have a profound influence on the development of anti-parasitic vaccines. PMID:27600086

  19. RNAi from plants to nematodes.

    PubMed

    Gheysen, Godelieve; Vanholme, Bartel

    2007-03-01

    Coincident with the award of the Nobel Prize for Medicine in 2006 to Fire and Mello for their discovery of RNAi, plant scientists have succeeded in using RNAi-based techniques to control nematodes, a hitherto unmanageable plant parasite. Recent work has demonstrated that the expression in a host plant of double-stranded RNA targeting housekeeping or parasitism genes in the root-knot nematode resulted in resistance to nematode infection.

  20. Toward 959 nematode genomes

    PubMed Central

    Kumar, Sujai; Koutsovoulos, Georgios; Kaur, Gaganjot; Blaxter, Mark

    2012-01-01

    The sequencing of the complete genome of the nematode Caenorhabditis elegans was a landmark achievement and ushered in a new era of whole-organism, systems analyses of the biology of this powerful model organism. The success of the C. elegans genome sequencing project also inspired communities working on other organisms to approach genome sequencing of their species. The phylum Nematoda is rich and diverse and of interest to a wide range of research fields from basic biology through ecology and parasitic disease. For all these communities, it is now clear that access to genome scale data will be key to advancing understanding, and in the case of parasites, developing new ways to control or cure diseases. The advent of second-generation sequencing technologies, improvements in computing algorithms and infrastructure and growth in bioinformatics and genomics literacy is making the addition of genome sequencing to the research goals of any nematode research program a less daunting prospect. To inspire, promote and coordinate genomic sequencing across the diversity of the phylum, we have launched a community wiki and the 959 Nematode Genomes initiative (www.nematodegenomes.org/). Just as the deciphering of the developmental lineage of the 959 cells of the adult hermaphrodite C. elegans was the gateway to broad advances in biomedical science, we hope that a nematode phylogeny with (at least) 959 sequenced species will underpin further advances in understanding the origins of parasitism, the dynamics of genomic change and the adaptations that have made Nematoda one of the most successful animal phyla. PMID:24058822

  1. Neuroparasitic Infections: Nematodes

    PubMed Central

    Walker, M.D.; Zunt, J.R.

    2009-01-01

    Globalization has produced an increase in the number of people at risk for contracting parasitic infection. Central nervous system infection by nematodal parasites can be devastating. Early recognition and treatment of infection can significantly decrease morbidity of the parasitic infection, as well as the risk of secondary superinfection. The clinical presentation, diagnosis, and treatment for five of the more common nematodal infections of the nervous system—Angiostrongylus spp., Baylisacaris procyonis, Gnathostoma spinigerum, Strongyloides stercoralis, and Toxocara spp.—is reviewed. Objectives On completion of this article, the reader should be able to summarize the clinical presentation, diagnosis, and treatment of the common nematodal infections of the nervous system. Accreditation The Indiana University School of Medicine is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. Credit The Indiana University School of Medicine designates this educational activity for a maximum of 1 Category 1 credit toward the AMA Physicians Recognition Award. Each physician should claim only those credits that he/she actually spent in the educational activity. Disclosure Statements of disclosure have been obtained regarding the authors’ relevant financial relationships. The authors have nothing to disclose. PMID:16170738

  2. Intestinal nematodes: biology and control.

    PubMed

    Epe, Christian

    2009-11-01

    A variety of nematodes occur in dogs and cats. Several nematode species inhabit the small and large intestines. Important species that live in the small intestine are roundworms of the genus Toxocara (T canis, T cati) and Toxascaris (ie, T leonina), and hookworms of the genus Ancylostoma (A caninum, A braziliense, A tubaeforme) or Uncinaria (U stenocephala). Parasites of the large intestine are nematodes of the genus Trichuris (ie, whipworms, T vulpis). After a comprehensive description of their life cycle and biology, which are indispensable for understanding and justifying their control, current recommendations for nematode control are presented and discussed thereafter.

  3. New frontiers in nematode ecology.

    PubMed

    Ferris, H

    1993-09-01

    Future areas of emphasis for research and scholarship in nematode ecology are indicated by pressing agricultural and environmental issues, by new directions in applied nematology, and by current technological advances. Studies in nematode ecology must extend beyond observation, counting, and simple statistical analysis. Experimentation and the testing of hypotheses are needed for understanding the biological mechanisms of ecological systems. Opportunities for fruitful experimentation in nematode ecology are emerging at the ecosystem, community, population, and individual levels. Nematode ecologists will best promote their field of study by closely monitoring and participating in the advances, initiatives, developments, and directions in the larger field of ecology.

  4. New Frontiers in Nematode Ecology

    PubMed Central

    Ferris, Howard

    1993-01-01

    Future areas of emphasis for research and scholarship in nematode ecology are indicated by pressing agricultural and environmental issues, by new directions in applied nematology, and by current technological advances. Studies in nematode ecology must extend beyond observation, counting, and simple statistical analysis. Experimentation and the testing of hypotheses are needed for understanding the biological mechanisms of ecological systems. Opportunities for fruitful experimentation in nematode ecology are emerging at the ecosystem, community, population, and individual levels. Nematode ecologists will best promote their field of study by closely monitoring and participating in the advances, initiatives, developments, and directions in the larger field of ecology. PMID:19279783

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

    PubMed

    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.

  6. Circulating Microbial Products and Acute Phase Proteins as Markers of Pathogenesis in Lymphatic Filarial Disease

    PubMed Central

    Anuradha, R.; George, P. Jovvian; Pavan Kumar, N.; Fay, Michael P.; Kumaraswami, V.; Nutman, Thomas B.; Babu, Subash

    2012-01-01

    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. PMID:22685406

  7. Filarial chyluria: long-term experience of a university hospital in India.

    PubMed

    Tandon, Vipul; Singh, Harbans; Dwivedi, U S; Mahmood, Mufti; Singh, P B

    2004-04-01

    Filariasis is an endemic problem in various Indian states. We evaluated the results of long-term follow up (10-20 years) of patients with filarial chyluria. We conducted a retrospective analysis of 160 patients treated for filarial chyluria who presented to the Banaras Hindu University Hospital from 1982 to 1992. Eighty-four patients (52.5%) were treated using diethylcarbamazine (DEC) and a fat restricted diet and 76 patients (47.5%) underwent surgery. To examine the long-term effects of filarial chyluria we analysed data on post-treatment recurrence, weight gain, dietary freedom, chyluria free period and a number of other associated factors. Previous history of filariasis or its complication was documented in 19% of patients. In 71% of cases, cystoscopy showed that chylous efflux was predominant in the left ureteric orifice. The long-term remission rate was 62% in the conservatively managed group (DEC + fat restricted diet), whereas 90% of patients in the operated group were cured. Postoperative recurrence rate was 10%. There was more weight gain and dietary freedom along with a longer chyluria free period in the operated group relative to the conservatively managed group. Definitive surgical ablation of lymphatic urinary fistula is better than conservative medical management because it has a higher success rate, more dietary freedom and, therefore, better patient acceptability.

  8. Caspase Dependent Programmed Cell Death in Developing Embryos: A Potential Target for Therapeutic Intervention against Pathogenic Nematodes

    PubMed Central

    Mohapatra, Alok Das; Kumar, Sunil; Satapathy, Ashok Kumar; Ravindran, Balachandran

    2011-01-01

    Background Successful embryogenesis is a critical rate limiting step for the survival and transmission of parasitic worms as well as pathology mediated by them. Hence, blockage of this important process through therapeutic induction of apoptosis in their embryonic stages offers promise for developing effective anti-parasitic measures against these extra cellular parasites. However, unlike in the case of protozoan parasites, induction of apoptosis as a therapeutic approach is yet to be explored against metazoan helminth parasites. Methodology/Principal Findings For the first time, here we developed and evaluated flow cytometry based assays to assess several conserved features of apoptosis in developing embryos of a pathogenic filarial nematode Setaria digitata, in-vitro as well as ex-vivo. We validated programmed cell death in developing embryos by using immuno-fluorescence microscopy and scoring expression profile of nematode specific proteins related to apoptosis [e.g. CED-3, CED-4 and CED-9]. Mechanistically, apoptotic death of embryonic stages was found to be a caspase dependent phenomenon mediated primarily through induction of intracellular ROS. The apoptogenicity of some pharmacological compounds viz. DEC, Chloroquine, Primaquine and Curcumin were also evaluated. Curcumin was found to be the most effective pharmacological agent followed by Primaquine while Chloroquine displayed minimal effect and DEC had no demonstrable effect. Further, demonstration of induction of apoptosis in embryonic stages by lipid peroxidation products [molecules commonly associated with inflammatory responses in filarial disease] and demonstration of in-situ apoptosis of developing embryos in adult parasites in a natural bovine model of filariasis have offered a framework to understand anti-fecundity host immunity operational against parasitic helminths. Conclusions/Significance Our observations have revealed for the first time, that induction of apoptosis in developing embryos can

  9. The Immunodominant Brugia malayi Paramyosin as a Marker of Current Infection with Wuchereria bancrofti Adult Worms

    PubMed Central

    Langy, Sandra; Plichart, Catherine; Luquiaud, Patrick; Williams, Steven A.; Nicolas, Luc

    1998-01-01

    The full-length cDNA sequence encoding Brugia malayi L3 paramyosin has been isolated by immunoscreening a cDNA library with a mouse antiserum raised against Wuchereria bancrofti L3 infective larvae. A recombinant truncated form of paramyosin was expressed as a glutathione S-transferase fusion protein and used to evaluate humoral responses of adults from a W. bancrofti-endemic area in French Polynesia according to their parasitological status. Immunoglobulin G4 (IgG4) preferentially bound to paramyosin in W. bancrofti-parasitized individuals, in contrast to unparasitized individuals, who harbored neither microfilaria nor Og4C3 adult worm circulating antigen. Reduction of the anti-paramyosin IgG4 titer following combined chemotherapy with diethylcarbamazine and ivermectin was significantly correlated with a reduction in the adult worm burden. This indicates that the presence of paramyosin-reactive IgG4 is associated with the presence of parasites and that reduction can be used as an immunological marker for W. bancrofti clearance. PMID:9596759

  10. Inventory and analysis of ATP-binding cassette (ABC) systems in Brugia malayi.

    PubMed

    Ardelli, B F; Stitt, L E; Tompkins, J B

    2010-07-01

    ABC systems are one of the largest described protein superfamilies. These systems have a domain organization that may contain 1 or more transmembrane domains (ABC_TM1F) and 1 or 2 ATP-binding domains (ABC_2). The functions (e.g., import, export and DNA repair) of these proteins distinguish the 3 classes of ABC systems. Mining and PCR-based cloning were used to identify 33 putative ABC systems from the Brugia malayi genome. There were 31 class 2 genes, commonly called ABC transporters, and 2 class 3 genes. The ABC transporters were divided into subfamilies. Three belonged to subfamily A, 16 to subfamily B, 5 to subfamily C, 1 to subfamily E and 3 to subfamilies F and G, respectively. None were placed in subfamilies D and H. Similar to other ABC systems, the ABC_2 domain of B. malayi genes was conserved and contained the Walker A and B motifs, the signature sequence/linker region and the switch region with the conserved histidine. The ABC_TM1F domain was less conserved. The relative abundance of ABC systems was quantified using real-time reverse transcription PCR and was significantly higher in female adults of B. malayi than in males and microfilaria, particularly those in subfamilies B and C, which are associated with drug resistance.

  11. In vitro radioisotopic labeling of the L-3 stage of Brugia malayi.

    PubMed

    Lengemann, F W; Marchell, T F; Chmielewicz, M; Georgi, J R

    1986-07-01

    Ten radioisotopes (133Ba, 207Bi, 109Cd, 51Cr, 59Fe, 203Hg, 54Mn, 125Sb and 75Se) were used to label the L-3 stage of Brugia malayi. The in vitro uptake at 4 hours in a buffered salt solution was greatest for 207Bi and exceeded that of 203Hg, by a factor of 6 and the rest of the radionuclides by factors of 26 or more. Dimethylsulfoxide (DMSO) (1%) in the medium only slightly enhanced the uptake of 207Bi but increased 203Hg uptake by a factor of 2.5. After incubation in non-radioactive medium only 2% of the 207Bi was retained; for 203Hg the retention was 70% or better. Increasing the labeling time increased total uptake and retention of the radionuclides. The retention of the 203Hg injected intraperitoneally into jirds (Meriones unguiculatus) in the form of labeled L-3s was followed over a 16 day period by counting the jirds in a whole animal NaI crystal detector. One L-4 stage of B malayi was recovered at the end of this period.

  12. In vitro radioisotopic labeling of the L-3 stage of Brugia malayi

    SciTech Connect

    Lengemann, F.W.; Marchell, T.F.; Chmielewicz, M.; Georgi, J.R.

    1986-07-01

    Ten radioisotopes (/sup 133/Ba, /sup 207/Bi, /sup 109/Cd, /sup 51/Cr, /sup 59/Fe, /sup 203/Hg, /sup 54/Mn, /sup 125/Sb and /sup 75/Se) were used to label the L-3 stage of Brugia malayi. The in vitro uptake at 4 hours in a buffered salt solution was greatest for /sup 207/Bi and exceeded that of /sup 203/Hg, by a factor of 6 and the rest of the radionuclides by factors of 26 or more. Dimethylsulfoxide (DMSO) (1%) in the medium only slightly enhanced the uptake of /sup 207/Bi but increased /sup 203/Hg uptake by a factor of 2.5. After incubation in non-radioactive medium only 2% of the /sup 207/Bi was retained; for /sup 203/Hg the retention was 70% or better. Increasing the labeling time increased total uptake and retention of the radionuclides. The retention of the /sup 203/Hg injected intraperitoneally into jirds (Meriones unguiculatus) in the form of labeled L-3s was followed over a 16 day period by counting the jirds in a whole animal NaI crystal detector. One L-4 stage of B malayi was recovered at the end of this period.

  13. Growth and development of Brugia pahangi larvae under various in vitro conditions.

    PubMed

    Wisnewski, N; Weinstein, P P

    1993-06-01

    In vitro culture methods were utilized to investigate specific nutritional requirements of Brugia pahangi larvae. Infective third-stage larvae (L3) isolated from Aedes aegypti (Liverpool) mosquitoes were cultured in NCTC 135:IMDM (NI) medium plus various types of serum under 5% CO2/air and 5% CO2/N2 atmospheres. Larvae grew, developed, and molted to the fourth stage (L4); however, further growth and differentiation beyond the mid-L4 were minimal. Serum supplementation was necessary to induce molting of B. pahangi L3s. Iron-supplemented calf serum (FeCS) consistently promoted higher percentages of molting than the other 4 types of serum tested. Specific nutritional requirements for B. pahangi larvae were assessed through testing of supplements known to be important for growth of mammalian cells or other parasites in vitro. Addition of various concentrations and combinations of hemoglobin, insulin, transferrin, selenium, albumin, cholesterol, or a cell feeder layer did not improve larval growth, molting, or survival compared to that obtained with FeCS alone. The L4s derived from in vitro culture, when injected intraperitoneally into jirds, developed to sexually mature, microfilarial-producing adults in a normal in vivo time frame. Developing L4s isolated from jirds molted to young adults in vitro in NI medium plus serum.

  14. Antifilarial activity of Zoanthus species (Phylum Coelenterata, Class Anthzoa) against human lymphatic filaria, Brugia malayi.

    PubMed

    Lakshmi, V; Saxena, A; Pandey, K; Bajpai, Preeti; Misra-Bhattacharya, Shailja

    2004-07-01

    The chloroform methanol (1:1) extract of an unidentified green zoanthus (Phylum Coelenterata, Class Anthozoa) showed promising in vitro adulticidal activity with a lethal concentration of 125 microg/ml on Brugia malayi. This extract brought about a 52.2% reduction in circulating microfilariae of B. malayi when administered to infected Mastomys coucha at 250 mg/kg, orally for 5 consecutive days. Further fractionation of the extract led to the recovery of four fractions, which were evaluated simultaneously in both in vitro and in vivo systems against B. malayi. The chloroform fraction at 250 mg/kg orally for 5 days exhibited the highest macrofilaricidal action (42.5%), closely followed by the insoluble n-butanol fraction (34.3%), the soluble hexane fraction (32.4%), and the soluble n-butanol fraction (20.4%). In addition, the hexane soluble fraction caused 44.3% sterilization of the surviving female parasites. Two compounds isolated were found devoid of antifilarial activity. Copyright 2004 Springer-Verlag

  15. Immunity to Brugia pahangi in athymic nude and normal mice: eosinophilia, antibody and hypersensitivity responses.

    PubMed

    Vickery, A C; Vincent, A L

    1984-11-01

    Congenitally athymic nude (nu/nu) mice, immunologically reconstituted by thymus grafting before inoculation with infective larvae, and mice heterozygous for the nu gene (nu/+), mounted potent protective humoral and cellular immune responses to Brugia pahangi. Although responses were not identical, both groups of mice produced IgM, IgG and IgE antibodies specific for adult worm antigen (S-Ag) present in a crude aqueous extract, made immediate and delayed hypersensitivity footpad swelling responses when challenged with S-Ag and eliminated their infection in the early larval stages. Heterozygotes also exhibited a marked eosinophilia which peaked coincident with larval killing. In contrast, thymus grafting of patent nudes had no effect upon microfilaraemias or adult worm burdens and did not completely protect against a challenge larval inoculum although antibodies specific for S-Ag were produced. With the occasional exceptions of moderate immediate footpad swelling and very low titres of IgM specific for S-Ag, no specific immune responses to B. pahangi were found in ungrafted nude mice which allowed full development of adult worms and supported patent infections.

  16. Parasitological, serological, and clinical evidence for high prevalence of podoconiosis (non-filarial elephantiasis) in Midakegn district, central Ethiopia

    PubMed Central

    Oli, Geleta Geshere; Ayele, Fasil Tekola; Petros, Beyene

    2012-01-01

    OBJECTIVE Both podoconiosis (a geochemical non-filarial disease) and chronic filarial disease result in lower limb elephantiasis. The aims of the present study were to determine whether the elephantiasis in Midakegn district, central Ethiopia is filarial or non-filarial (podoconiosis) using serological, parasitological, and clinical examinations, and to estimate its prevalence. METHODS House-to-house visits were made in 330 randomly selected households. All household members that had elephantiasis were interviewed and clinically examined at the nearby health center to confirm presence of elephantiasis, check presence of scrotal swelling, and rule out other causes of lymphoedema. Midnight blood sample was obtained from each participant with elephantiasis for microscopic examination of W. bancrofti microfilaria. Day time blood sample was obtained from half of the participants for serological confirmation using the immuno-chromatographic test card. RESULTS Consistent with features of podoconiosis (non-filarial elephantiasis), none of the elephantiasis cases had consistently worn shoes since childhood; 94.3% had bilateral swelling limited below the level of the knees; no individual had thigh or scrotal elephantiasis; parasitological test for microfilariae and serological tests for W. bancrofti antigen turned negative in all samples. The prevalence of the disease was 7.4%. Prevalence peaked in the third decade of life, which also includes the most economically active age groups. CONCLUSIONS This study has shown high prevalence of podoconiosis (endemic non-filarial elephantiasis) and absence of filarial elephantiasis in Midakegn district. Prevention, treatment, and control of podoconiosis must be among the top priorities of public health programs in the district. PMID:22487446

  17. Bacteria can mobilize nematode-trapping fungi to kill nematodes.

    PubMed

    Wang, Xin; Li, Guo-Hong; Zou, Cheng-Gang; Ji, Xing-Lai; Liu, Tong; Zhao, Pei-Ji; Liang, Lian-Ming; Xu, Jian-Ping; An, Zhi-Qiang; Zheng, Xi; Qin, Yue-Ke; Tian, Meng-Qing; Xu, You-Yao; Ma, Yi-Cheng; Yu, Ze-Fen; Huang, Xiao-Wei; Liu, Shu-Qun; Niu, Xue-Mei; Yang, Jin-Kui; Huang, Ying; Zhang, Ke-Qin

    2014-12-16

    In their natural habitat, bacteria are consumed by bacterivorous nematodes; however, they are not simply passive preys. Here we report a defensive mechanism used by certain bacteria to mobilize nematode-trapping fungi to kill nematodes. These bacteria release urea, which triggers a lifestyle switch in the fungus Arthrobotrys oligospora from saprophytic to nematode-predatory form; this predacious form is characterized by formation of specialized cellular structures or 'traps'. The bacteria significantly promote the elimination of nematodes by A. oligospora. Disruption of genes involved in urea transport and metabolism in A. oligospora abolishes the urea-induced trap formation. Furthermore, the urea metabolite ammonia functions as a signal molecule in the fungus to initiate the lifestyle switch to form trap structures. Our findings highlight the importance of multiple predator-prey interactions in prey defense mechanisms.

  18. Managing Nematodes without Methyl Bromide

    USDA-ARS?s Scientific Manuscript database

    Methyl bromide is an effective pre-plant soil fumigant used to control nematodes in many high-input, high-value production systems including vegetables, nurseries, ornamentals, tree fruits, strawberries, and grapes. Because methyl bromide has provided a reliable return on investment for nematode c...

  19. Social networks of educated nematodes

    USDA-ARS?s Scientific Manuscript database

    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...

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-09-10

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

  2. Interactions of microfungi and plant parasitic nematodes

    USDA-ARS?s Scientific Manuscript database

    Plant parasitic nematodes and microfungi inhabit many of the same ecological habitats and interact in almost every conceivable way. Nematodes can feed on fungi, and conversely fungi can use nematodes as a food source. Fungi have been widely studied as biological controls of plant parasitic nematod...

  3. Live Brugia malayi microfilariae inhibit transendothelial migration of neutrophils and monocytes.

    PubMed

    Schroeder, Jan-Hendrik; Simbi, Bigboy H; Ford, Louise; Cole, Sara R; Taylor, Mark J; Lawson, Charlotte; Lawrence, Rachel A

    2012-01-01

    Lymphatic filariasis is a major tropical disease caused by the parasite Brugia malayi. Microfilariae (Mf) circulate in the peripheral blood for 2-3 hours in synchronisation with maximal feeding of the mosquito vector. When absent from the peripheral blood, Mf sequester in the capillaries of the lungs. Mf are therefore in close contact with vascular endothelial cells (EC) and may induce EC immune function and/or wound repair mechanisms such as angiogenesis. In this study, Mf were co-cultured with human umbilical vein EC (HUVEC) or human lung microvascular EC (HLMVEC) and the transendothelial migration of leukocyte subsets was analysed. In addition, the protein and/or mRNA expression of chemokine, cytokine and angiogenic mediators in endothelial cells in the presence of live microfilariae were measured by a combination of cDNA arrays, protein arrays, ELISA and fluorescence antibody tests.Surprisingly, our findings indicate that Mf presence partially blocked transendothelial migration of monocytes and neutrophils, but not lymphocytes. However, Mf exposure did not result in altered vascular EC expression of key mediators of the tethering stage of extravasation, such as ICAM-1, VCAM-1 and various chemokines. To further analyse the immunological function of vascular EC in the presence of Mf, we measured the mRNA and/or protein expression of a number of pro-inflammatory mediators. We found that expression levels of the mediators tested were predominantly unaltered upon B. malayi Mf exposure. In addition, a comparison of angiogenic mediators induced by intact Mf and Wolbachia-depleted Mf revealed that even intact Mf induce the expression of remarkably few angiogenic mediators in vascular EC. Our study suggests that live microfilariae are remarkably inert in their induction and/or activation of vascular cells in their immediate local environment. Overall, this work presents important insights into the immunological function of the vascular endothelium during an infection

  4. Susceptibility of Mansonia uniformis to Brugia malayi microfilariae from infected domestic cat.

    PubMed

    Lek-Uthai, Usa; Tomoen, Wanachai

    2005-03-01

    Microfilariae of Brugia malayi is transmitted to man and other susceptible hosts via mosquito. The transmission of B. malayi from cat to man by Ma. uniformis bite has never been reported. The Ma. uniformis mosquito is the normal vector for Wuchereria bancrofti but has never been reported as a vector for B. malayi, or a susceptible host for the growth and development of the microfilariae of B. malayi. The purpose of this study was to examine the development of B. malayi in Mansonia uniformis after feeding on the blood of an infected cat in the laboratory. The B. malayi infected cat was identified using PCR with the primers Bm-1/Bm-2 on DNA (at 10 ng/50 microl) extracted from the WBC of the cat. W. bancrofti was employed as a negative control. The sensitivity of the B. malayi DNA detection by PCR was 0.0001 ng. Adult Ma. uniformis mosquitos at the ages of 5, 10, and 15 days, 100 mosquitos in each group, were fed on the infected cat blood. Recovery of third stage microfilariae was found to be the highest in the 5-day old mosquito group (48%), followed by the 10- and 15-day old mosquito groups (32% and 18%, respectively). The mean number of B. malayi microfilariae found in thorax, head, and abdomen of the mosquitos were composed. The 5-day old (40.3%) and 10-day old (41.9%) mosquitos were significantly more susceptible to microfilariae than the 15-day old mosquitos (17.8%) (p-values using the Scheffe method: 0.027 and 0.039, respectively). There was no significant difference in the mean number of microfilariae in the thorax (p = 0.482) by age, but the mean numbers of microfilariae in the heads, and abdomens were significantly different by age between the 5- and10-, and the 15-day old mosquitos (p < 0.001 and p = 0.004, respectively).

  5. Effect of immune reconstitution on resistance to Brugia pahangi in congenitally athymic nude mice.

    PubMed

    Vickery, A C; Vincent, A L; Sodeman, W A

    1983-06-01

    The dichotomy of resistance to Brugia pahangi (Nematoda: Filarioidea) between nonsusceptible, euthymic C3H/HeN mice, heterozygotic for the "nu" gene (+/nu), and susceptible, congenitally-athymic "nude" (nu/nu) C3H/HeN mice, suggests that resistance is thymus-dependent. To test this hypothesis, the effect of syngeneic neonatal thymus grafts and neonatal thymus cell suspensions on recovery of worms at day 40 PI, and responses to Concanavalin A (Con A) were examined in reconstituted nudes. Nude recipients of a thymus graft 7 or 14 wk before subcutaneous inoculation with 50 infective larvae (L3) yielded no worms and responded strongly to Con A. Serum from these mice reacted in two lines of identity with serum from similarly-infected heterozygotes by double radial immunodiffusion against an adult worm saline extract. Nude recipients of a thymus 2 days or 3 wk before inoculation harbored an average of three or two worms, respectively. Intravenous injection of nude recipients with 10(7) or 10(8) neonatal thymus cells seven weeks before inoculation was less effective in conferring resistance to B. pahangi and responsiveness to Con A. Complete resistance to B. pahangi could be adoptively transferred to nude mice by 10(8) spleen cells obtained from infection-primed heterozygotes and injected intravenously on the day of larval inoculation. The same numbers of worms were significantly reduced. less effective when injected 3 wk before inoculation, although numbers of worms were significantly reduced. Passive transfer of primed heterozygote serum, containing high titers of antibodies to adult worm and larval antigens, failed to protect nude recipients against a larval inoculum in the absence of cellular reconstitution.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Profiling the macrofilaricidal effects of flubendazole on adult female Brugia malayi using RNAseq.

    PubMed

    O'Neill, Maeghan; Ballesteros, Cristina; Tritten, Lucienne; Burkman, Erica; Zaky, Weam I; Xia, Jianguo; Moorhead, Andrew; Williams, Steven A; Geary, Timothy G

    2016-12-01

    The use of microfilaricidal drugs for the control of onchocerciasis and lymphatic filariasis (LF) necessitates prolonged yearly dosing. Prospects for elimination or eradication of these diseases would be enhanced by the availability of a macrofilaricidal drug. Flubendazole (FLBZ), a benzimidazole anthelmintic, is an appealing candidate. FLBZ has demonstrated potent macrofilaricidal effects in a number of experimental rodent models and in one human trial. Unfortunately, FLBZ was deemed unsatisfactory for use in mass drug administration campaigns due to its limited oral bioavailability. A new formulation that enables sufficient bioavailability following oral administration could render FLBZ an effective treatment for onchocerciasis and LF. Identification of drug-derived effects is important in ascertaining a dosage regimen which is predicted to be lethal to the parasite in situ. In previous histological studies, exposure to FLBZ induced damage to tissues required for reproduction and survival at pharmacologically relevant concentrations. However, more precise and quantitative indices of drug effects are needed. This study assessed drug effects using a transcriptomic approach to confirm effects observed histologically and to identify genes which were differentially expressed in treated adult female Brugia malayi. Comparative analysis across different concentrations (1 μM and 5 μM) and durations (48 and 120 h) provided an overview of the processes which are affected by FLBZ exposure. Genes with dysregulated expression were consistent with the reproductive effects observed via histology in our previous studies. This study revealed transcriptional changes in genes involved in embryo development. Additionally, significant downregulation was observed in genes encoding cuticle components, which may reflect changes in developing embryos, the adult worm cuticle or both. These data support the hypothesis that FLBZ acts predominantly on rapidly dividing cells, and provides

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

    PubMed Central

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

    2016-01-01

    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. PMID:26486636

  8. Factors affecting response to medical management in patients of filarial chyluria: A prospective study.

    PubMed

    Goyal, Neeraj Kumar; Goel, Apul; Sankhwar, Satyanarayan; Singh, Vishwajeet; Ali, Wahid; Natu, S M; Singh, Bhupendra Pal; Sinha, Rahul Janak; Dalela, Divakar

    2014-01-01

    Filarial chyluria is a common problem in filarial endemic countries. Its management begins with medical therapy but some patients progress to require surgery. The present study aimed to determine factors affecting response to medical management in patients of filarial chyluria. This prospective study conducted between August 2008 and November 2012, included conservatively managed patients of chyluria. Demographic profile, clinical presentation, treatment history and urinary triglycerides (TGs) and cholesterol levels at baseline were compared between the responders and non-responders. Apart from the clinical grade of chyluria, hematuria was evaluated as an independent risk factor. Out of the 222 patients (mean age, 37.99 ± 13.29 years, 129 males), 31 patients failed to respond while 35 had a recurrence after initial response; the overall success rate being 70.3% at a mean follow-up of 25 months. No difference was observed in demographics, clinical presentation, presence of hematuria, disease duration and mean urinary TGs loss between responders and non-responders. On multivariate analysis, patients with treatment failure were found to have a higher-grade disease (14.3% Grade-I, 36.6% Grades-II and 60% Grade-III), higher number of pretreatment courses (1.59 ± 1.08 vs. 1.02 ± 0.79) and heavier cholesterol (26.54 ± 23.46 vs. 8.81 ± 8.55 mg/dl) loss at baseline compared with responders (P < 0.05). Conservative management has a success rate in excess of 70%, not affected by the disease chronicity, previous episodes and recurrent nature. However, higher-grade disease, extensive pre-treatment with drugs and higher urinary cholesterol loss at baseline are the predictors of poor response. Hematuria is not an independent poor risk factor for conservative management.

  9. Hypothalamic-pituitary gonadal axis and immune response imbalance during chronic filarial infections.

    PubMed

    Mavoungou, Donatien; Poaty-Mavoungou, Virginie; Ongali, Brice; Akoume, Marie Yvonne; Maka, Gontran; Mavoungou, Elie

    2005-11-01

    Bi-directional relationships operate between the hypothalamic-pituitary-gonadal axis and the immune system. Cytokines, peptide hormones and their shared receptors/ligands are used as a common biological language for communication within and between the immune and neuroendocrine systems. Such communication suggests an immunoregulatory role for the brain and a sensory function for the immune system. We used a radioimmunoassay to measure the concentrations of steroid hormones (cortisol, testosterone, estradiol and progesterone) and pituitary hormones [follicle stimulating hormone (FSH), luteinizing hormone (LH) human chorionic gonadotropin (HCG) and prolactin] in peripheral blood plasma from 78 young Gabonese women with chronic filarial infections. We used an enzyme-linked immunosorbent assay to determine the concentrations of four proinflammatory cytokines [tumor necrosis factor-alpha (TNF-alpha), gamma interferon (IFN-gamma), interleukin-1 (IL-1) and IL-6] in the same plasma samples. Progesterone was unchanged and all other steroid hormone plasma concentrations were lower in microfilaremic women than in amicrofilaremic women. The concentration of LH was higher in amicrofilaremic women, whereas the prolactin concentration was higher in microfilaremics. The plasma concentrations of TNF-alpha, IFN-gamma, IL-1 and IL-6 were higher in microfilaremic women. A strong negative correlation was found between the steroid and pituitary hormones and the pro-inflammatory cytokines. Conversely, a strong positive correlation was found between prolactin and the same cytokines. These data provide first evidence of immune system and hormonal system disturbance during chronic filarial infections and suggest that the observed imbalance should be taken into account in the diagnosis and treatment of filarial infections.

  10. Bacteria can mobilize nematode-trapping fungi to kill nematodes

    PubMed Central

    Wang, Xin; Li, Guo-Hong; Zou, Cheng-Gang; Ji, Xing-Lai; Liu, Tong; Zhao, Pei-Ji; Liang, Lian-Ming; Xu, Jian-Ping; An, Zhi-Qiang; Zheng, Xi; Qin, Yue-Ke; Tian, Meng-Qing; Xu, You-Yao; Ma, Yi-Cheng; Yu, Ze-Fen; Huang, Xiao-Wei; Liu, Shu-Qun; Niu, Xue-Mei; Yang, Jin-Kui; Huang, Ying; Zhang, Ke-Qin

    2014-01-01

    In their natural habitat, bacteria are consumed by bacterivorous nematodes; however, they are not simply passive preys. Here we report a defensive mechanism used by certain bacteria to mobilize nematode-trapping fungi to kill nematodes. These bacteria release urea, which triggers a lifestyle switch in the fungus Arthrobotrys oligospora from saprophytic to nematode–predatory form; this predacious form is characterized by formation of specialized cellular structures or ‘traps’. The bacteria significantly promote the elimination of nematodes by A. oligospora. Disruption of genes involved in urea transport and metabolism in A. oligospora abolishes the urea-induced trap formation. Furthermore, the urea metabolite ammonia functions as a signal molecule in the fungus to initiate the lifestyle switch to form trap structures. Our findings highlight the importance of multiple predator–prey interactions in prey defense mechanisms. PMID:25514608

  11. In vitro antifilarial activity of organometallic complexes against infective larvae of Molinema dessetae and adult females of Brugia pahangi.

    PubMed

    Loiseau, P M; Jaffe, J J; Craciunescu, D G

    1998-08-01

    New organometallic complexes having protozoocidal properties were evaluated for their in vitro antifilarial activity using two models: infective larvae of Molinema dessetae and adult females of Brugia pahangi. The compound most active on the M. dessetae model was Ir(I)-COD-pentamidine tetraphenylborate with an EC50 = 6 +/- 1 microM after 7-day-incubation. In the 2-aminobenzothiazole series, Ruthenium was more potent than Iridium for antifilarial activity. A dithiocarbamate function significantly enhanced the antifilarial activity. The compounds derived from benzimidazole were inactive whatever the metal (Iridium or Rhodium). The other compounds exhibited EC50 ranging from 10 to 31 microM. On adult female Brugia pahangi in vitro, Pt-DDH-N-acetylleucine, Pt-diminazene and Pd-Cl4-piperazine at 20 microM began to kill both microfilariae and the developing embryos within the mothers on day 2. The compounds, except for Pd-Cl4-piperazine, killed the adults after 5 days. Rh-Cl-2-chloropyridine caused obvious slowing of the adults from day 3 onward but did not affect the viability of adults, microfilariae or developing embryos. In vivo antifilarial investigations are necessary to appreciate the real advantage of heavy metal complexes in the experimental treatment of filariasis.

  12. Amelanotic Melanoma Arising in Filarial Leg: A Report of a Rare Case

    PubMed Central

    Nayak, Mamita; Meher, Susanta; Sasmal, Prakash Kumar

    2017-01-01

    Amelanotic melanoma arising on chronic lymphoedema has not been reported earlier. We reported a case of amelanotic melanoma of right leg developing in a background of chronic lymphoedema of filarial origin in an elderly male of 60 years, who underwent wide local excision of the lesion followed by skin grafting for the same. A histopathological diagnosis of amelanotic melanoma was made. The patient was on follow up when he developed brain metastasis within a period of nine months for which he was operated and is on regular follow up now. We believe this as the first case report of this unusual combination. PMID:28273977

  13. The Cyclooctadepsipeptide Anthelmintic Emodepside Differentially Modulates Nematode, Insect and Human Calcium-Activated Potassium (SLO) Channel Alpha Subunits

    PubMed Central

    Schoenhense, Eva; Harder, Achim; Raming, Klaus; O’Kelly, Ita; Ndukwe, Kelechi; O’Connor, Vincent; Walker, Robert J.; Holden-Dye, Lindy

    2015-01-01

    The anthelmintic emodepside paralyses adult filarial worms, via a mode of action distinct from previous anthelmintics and has recently garnered interest as a new treatment for onchocerciasis. Whole organism data suggest its anthelmintic action is underpinned by a selective activation of the nematode isoform of an evolutionary conserved Ca2+-activated K+ channel, SLO-1. To test this at the molecular level we compared the actions of emodepside at heterologously expressed SLO-1 alpha subunit orthologues from nematode (Caenorhabditis elegans), Drosophila melanogaster and human using whole cell voltage clamp. Intriguingly we found that emodepside modulated nematode (Ce slo-1), insect (Drosophila, Dm slo) and human (hum kcnma1)SLO channels but that there are discrete differences in the features of the modulation that are consistent with its anthelmintic efficacy. Nematode SLO-1 currents required 100 μM intracellular Ca2+ and were strongly facilitated by emodepside (100 nM; +73.0 ± 17.4%; n = 9; p<0.001). Drosophila Slo currents on the other hand were activated by emodepside (10 μM) in the presence of 52 nM Ca2+ but were inhibited in the presence of 290 nM Ca2+ and exhibited a characteristic loss of rectification. Human Slo required 300nM Ca2+ and emodepside transiently facilitated currents (100nM; +33.5 ± 9%; n = 8; p<0.05) followed by a sustained inhibition (-52.6 ± 9.8%; n = 8; p<0.001). This first cross phyla comparison of the actions of emodepside at nematode, insect and human channels provides new mechanistic insight into the compound’s complex modulation of SLO channels. Consistent with whole organism behavioural studies on C. elegans, it indicates its anthelmintic action derives from a strong activation of SLO current, not observed in the human channel. These data provide an important benchmark for the wider deployment of emodepside as an anthelmintic treatment. PMID:26437177

  14. A rapid colorimetric assay for the quantitation of the viability of free-living larvae of nematodes in vitro.

    PubMed

    James, Catherine E; Davey, Mary W

    2007-09-01

    With increasing drug resistance in gastrointestinal parasites, identification of new anthelmintics is essential. The non-parasitic nematode Caenorhabditis elegans is used extensively as a model to identify drug targets and potential novel anthelmintics because it can be readily cultured in vitro. Traditionally, the assessment of worm viability has relied on labour-intensive developmental and behavioral assays. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide-formazan (MTT-formazan) colorimetric assay uses metabolic activity as a marker of viability in mammalian cell culture systems and has been applied for use with filarial nematodes. In the present study, this assay has been optimized and validated to rapidly assess the viability of C. elegans after drug treatment. Living, but not dead, C. elegans take up MTT and reduce it to the blue formazan, providing visual, qualitative, and quantitative assessment of viability. MTT at a concentration of 5 mg/ml with 3 h incubation was optimal for detecting changes in viability with drug treatment. We have applied this assay to quantitate the effects of ivermectin and short-chain alcohols on the viability of C. elegans. This assay is also applicable to first-stage larvae of the parasitic nematode Haemonchus contortus. The advantage of this assay is the rapid quantitation in screening drugs to identify potential anthelmintics.

  15. Nematode-trapping fungi eavesdrop on nematode pheromones

    PubMed Central

    Hsueh, Yen-Ping; Mahanti, Parag; Schroeder, Frank C.; Sternberg, Paul W.

    2013-01-01

    Summary The recognition of molecular patterns associated with specific pathogens or food sources is fundamental to ecology and plays a major role in the evolution of predator-prey relationships [1]. Recent studies showed that nematodes produce an evolutionarily highly conserved family of small molecules, the ascarosides, which serve essential functions in regulating nematode development and behavior [2-4]. Here we show that nematophagous fungi, natural predators of soil-dwelling nematodes [5], can detect and respond to ascarosides. Nematophagous fungi use specialized trapping devices to catch and consume nematodes, and previous studies demonstrated that most fungal species do not produce traps constitutively but rather initiate trap-formation in response to their prey [6]. We found that ascarosides, which are constitutively secreted by many species of soil-dwelling nematodes, represent a conserved molecular pattern used by nematophagous fungi to detect prey and trigger trap formation. Ascaroside-induced morphogenesis is conserved in several closely related species of nematophagous fungi and occurs only under nutrient-deprived condition. Our results demonstrate that microbial predators eavesdrop on chemical communication among their metazoan prey to regulate morphogenesis, providing a striking example of predator-prey co-evolution. We anticipate that these findings will have broader implications for understanding other inter-kingdom interactions involving nematodes, which are found in almost any ecological niche on Earth. PMID:23246407

  16. Nematode-trapping fungi eavesdrop on nematode pheromones.

    PubMed

    Hsueh, Yen-Ping; Mahanti, Parag; Schroeder, Frank C; Sternberg, Paul W

    2013-01-07

    The recognition of molecular patterns associated with specific pathogens or food sources is fundamental to ecology and plays a major role in the evolution of predator-prey relationships. Recent studies showed that nematodes produce an evolutionarily highly conserved family of small molecules, the ascarosides, which serve essential functions in regulating nematode development and behavior. Here, we show that nematophagous fungi, natural predators of soil-dwelling nematodes, can detect and respond to ascarosides. Nematophagous fungi use specialized trapping devices to catch and consume nematodes, and previous studies demonstrated that most fungal species do not produce traps constitutively but rather initiate trap formation in response to their prey. We found that ascarosides, which are constitutively secreted by many species of soil-dwelling nematodes, represent a conserved molecular pattern used by nematophagous fungi to detect prey and trigger trap formation. Ascaroside-induced morphogenesis is conserved in several closely related species of nematophagous fungi and occurs only under nutrient-deprived conditions. Our results demonstrate that microbial predators eavesdrop on chemical communication among their metazoan prey to regulate morphogenesis, providing a striking example of predator-prey coevolution. We anticipate that these findings will have broader implications for understanding other interkingdom interactions involving nematodes, which are found in almost any ecological niche on Earth.

  17. Utilization of computer processed high definition video imaging for measuring motility of microscopic nematode stages on a quantitative scale: “The Worminator”

    PubMed Central

    Storey, Bob; Marcellino, Chris; Miller, Melissa; Maclean, Mary; Mostafa, Eman; Howell, Sue; Sakanari, Judy; Wolstenholme, Adrian; Kaplan, Ray

    2014-01-01

    A major hindrance to evaluating nematode populations for anthelmintic resistance, as well as for screening existing drugs, new compounds, or bioactive plant extracts for anthelmintic properties, is the lack of an efficient, objective, and reproducible in vitro assay that is adaptable to multiple life stages and parasite genera. To address this need we have developed the “Worminator” system, which objectively and quantitatively measures the motility of microscopic stages of parasitic nematodes. The system is built around the computer application “WormAssay”, developed at the Center for Discovery and Innovation in Parasitic Diseases at the University of California, San Francisco. WormAssay was designed to assess motility of macroscopic parasites for the purpose of high throughput screening of potential anthelmintic compounds, utilizing high definition video as an input to assess motion of adult stage (macroscopic) parasites (e.g. Brugia malayi). We adapted this assay for use with microscopic parasites by modifying the software to support a full frame analysis mode that applies the motion algorithm to the entire video frame. Thus, the motility of all parasites in a given well are recorded and measured simultaneously. Assays performed on third-stage larvae (L3) of the bovine intestinal nematode Cooperia spp., as well as microfilariae (mf) of the filarioid nematodes B. malayi and Dirofilaria immitis, yielded reproducible dose responses using the macrocyclic lactones ivermectin, doramectin, and moxidectin, as well as the nicotinic agonists, pyrantel, oxantel, morantel, and tribendimidine. This new computer based-assay is simple to use, requires minimal new investment in equipment, is robust across nematode genera and developmental stage, and does not require subjective scoring of motility by an observer. Thus, the “Worminator” provides a relatively low-cost platform for developing genera- and stage-specific assays with high efficiency and reproducibility, low

  18. Utilization of computer processed high definition video imaging for measuring motility of microscopic nematode stages on a quantitative scale: "The Worminator".

    PubMed

    Storey, Bob; Marcellino, Chris; Miller, Melissa; Maclean, Mary; Mostafa, Eman; Howell, Sue; Sakanari, Judy; Wolstenholme, Adrian; Kaplan, Ray

    2014-12-01

    A major hindrance to evaluating nematode populations for anthelmintic resistance, as well as for screening existing drugs, new compounds, or bioactive plant extracts for anthelmintic properties, is the lack of an efficient, objective, and reproducible in vitro assay that is adaptable to multiple life stages and parasite genera. To address this need we have developed the "Worminator" system, which objectively and quantitatively measures the motility of microscopic stages of parasitic nematodes. The system is built around the computer application "WormAssay", developed at the Center for Discovery and Innovation in Parasitic Diseases at the University of California, San Francisco. WormAssay was designed to assess motility of macroscopic parasites for the purpose of high throughput screening of potential anthelmintic compounds, utilizing high definition video as an input to assess motion of adult stage (macroscopic) parasites (e.g. Brugia malayi). We adapted this assay for use with microscopic parasites by modifying the software to support a full frame analysis mode that applies the motion algorithm to the entire video frame. Thus, the motility of all parasites in a given well are recorded and measured simultaneously. Assays performed on third-stage larvae (L3) of the bovine intestinal nematode Cooperia spp., as well as microfilariae (mf) of the filarioid nematodes B. malayi and Dirofilaria immitis, yielded reproducible dose responses using the macrocyclic lactones ivermectin, doramectin, and moxidectin, as well as the nicotinic agonists, pyrantel, oxantel, morantel, and tribendimidine. This new computer based-assay is simple to use, requires minimal new investment in equipment, is robust across nematode genera and developmental stage, and does not require subjective scoring of motility by an observer. Thus, the "Worminator" provides a relatively low-cost platform for developing genera- and stage-specific assays with high efficiency and reproducibility, low labor input

  19. Nematode Chemosensilla: Form and Function

    PubMed Central

    Wright, K. A.

    1983-01-01

    As an introduction to a symposium of nematode chemoreception, the anatomy of nematode chemosensilla, their distribution on plant parasitic nematodes, and their possible functional roles is briefly reviewed. Comparison of nematode chemosensilla with those of other animals shows their greater resemblance to olfactory primary sense cells of vertebrates. Although the sensory process is obviously derived from a cilium, the absence of many ciliary features is noted. Retention of the ciliary necklace may be important functionally. A simple model is proposed, wherein binding of stimulant molecules to receptors in the membrane of the cilium-derived process results in entry of Na⁺ and Ca⁺⁺ (the latter via the ciliary necklace) to produce a receptor potential that spreads along the dendrite to the cell body where action potentials continue along the short axon to synapses. PMID:19295785

  20. Social Networks of Educated Nematodes

    PubMed Central

    Willett, Denis S.; Alborn, Hans T.; Duncan, Larry W.; Stelinski, Lukasz L.

    2015-01-01

    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 specific manner, increasing preference for volatiles they previously were exposed to and decreasing attraction to other volatiles. In addition, persistence of volatile exposure influences this response. Longer exposure not only increases preference, but also results in longer retention of that preference. These entomopathogenic nematodes display interspecific social behavioral plasticity; experienced nematodes influence the behavior of different species. This interspecific social behavioral plasticity suggests a mechanism for rapid adaptation of belowground communities to dynamic environments. PMID:26404058

  1. Social Networks of Educated Nematodes.

    PubMed

    Willett, Denis S; Alborn, Hans T; Duncan, Larry W; Stelinski, Lukasz L

    2015-09-25

    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 specific manner, increasing preference for volatiles they previously were exposed to and decreasing attraction to other volatiles. In addition, persistence of volatile exposure influences this response. Longer exposure not only increases preference, but also results in longer retention of that preference. These entomopathogenic nematodes display interspecific social behavioral plasticity; experienced nematodes influence the behavior of different species. This interspecific social behavioral plasticity suggests a mechanism for rapid adaptation of belowground communities to dynamic environments.

  2. Herd immunity to filarial infection is a function of vector biting rate.

    PubMed Central

    Michael, E; Bundy, D A

    1998-01-01

    Despite the existence of an impressive body of work on human immune responses against filarial infections, the occurrence of a protective response to infection remains unclear. Here, we use a combined modelling and comparative data analysis framework to address this issue for human infections with the filarial parasite, Wuchereria bancrofti. By analogy with previous work, the analysis involves the comparison of observed field patterns of infection with epidemiological patterns predicted by a mathematical model of parasite immunity. Unlike most other human helminths, which are transmitted by ingestion or dermal penetration, exposure to infection with lymphatic filariasis can be measured explicitly in terms of vector mosquito biting rates, thereby also allowing, probably for the first time, examination of the suggested role of exposure in generating herd immunity to macroparasites. Observed field patterns in this study were derived from 19 different published studies, which gave parallel estimates of community exposure rates and the corresponding age--prevalence patterns of infection, while predictions of the epidemiological impact of herd immunity were obtained using a catalytic model framework. The results provide the first conclusive evidence to date that variations in the observed age--prevalence patterns of infection in filariasis can be effectively explained by the occurrence of an exposure-driven acquisition of herd immunity. We discuss this result in terms of implications for the new World Health Organization-led initiative for the global control of this parasitic disease. PMID:9633111

  3. Immunization with L. sigmodontis Microfilariae Reduces Peripheral Microfilaraemia after Challenge Infection by Inhibition of Filarial Embryogenesis

    PubMed Central

    Ziewer, Sebastian; Hübner, Marc P.; Dubben, Bettina; Hoffmann, Wolfgang H.; Bain, Odile; Martin, Coralie; Hoerauf, Achim; Specht, Sabine

    2012-01-01

    Background Lymphatic filariasis and onchocerciasis are two chronic diseases mediated by parasitic filarial worms causing long term disability and massive socioeconomic problems. Filariae are transmitted by blood-feeding mosquitoes that take up the first stage larvae from an infected host and deliver it after maturation into infective stage to a new host. After closure of vector control programs, disease control relies mainly on mass drug administration with drugs that are primarily effective against first stage larvae and require many years of annual/biannual administration. Therefore, there is an urgent need for alternative treatment ways, i.e. other effective drugs or vaccines. Methodology/Principal Findings Using the Litomosoides sigmodontis murine model of filariasis we demonstrate that immunization with microfilariae together with the adjuvant alum prevents mice from developing high microfilaraemia after challenge infection. Immunization achieved 70% to 100% protection in the peripheral blood and in the pleural space and furthermore strongly reduced the microfilarial load in mice that remained microfilaraemic. Protection was associated with the impairment of intrauterine filarial embryogenesis and with local and systemic microfilarial-specific host IgG, as well as IFN-γ secretion by host cells from the site of infection. Furthermore immunization significantly reduced adult worm burden. Conclusions/Significance Our results present a tool to understand the immunological basis of vaccine induced protection in order to develop a microfilariae-based vaccine that reduces adult worm burden and prevents microfilaraemia, a powerful weapon to stop transmission of filariasis. PMID:22413031

  4. Identification of Ecdysone Hormone Receptor Agonists as a Therapeutic Approach for Treating Filarial Infections

    PubMed Central

    Mhashilkar, Amruta S.; Vankayala, Sai L.; Liu, Canhui; Kearns, Fiona; Mehrotra, Priyanka; Tzertzinis, George; Palli, Subba R.; Woodcock, H. Lee; Unnasch, Thomas R.

    2016-01-01

    Background A homologue of the ecdysone receptor has previously been identified in human filarial parasites. As the ecdysone receptor is not found in vertebrates, it and the regulatory pathways it controls represent attractive potential chemotherapeutic targets. Methodology/ Principal Findings Administration of 20-hydroxyecdysone to gerbils infected with B. malayi infective larvae disrupted their development to adult stage parasites. A stable mammalian cell line was created incorporating the B. malayi ecdysone receptor ligand-binding domain, its heterodimer partner and a secreted luciferase reporter in HEK293 cells. This was employed to screen a series of ecdysone agonist, identifying seven agonists active at sub-micromolar concentrations. A B. malayi ecdysone receptor ligand-binding domain was developed and used to study the ligand-receptor interactions of these agonists. An excellent correlation between the virtual screening results and the screening assay was observed. Based on both of these approaches, steroidal ecdysone agonists and the diacylhydrazine family of compounds were identified as a fruitful source of potential receptor agonists. In further confirmation of the modeling and screening results, Ponasterone A and Muristerone A, two compounds predicted to be strong ecdysone agonists stimulated expulsion of microfilaria and immature stages from adult parasites. Conclusions The studies validate the potential of the B. malayi ecdysone receptor as a drug target and provide a means to rapidly evaluate compounds for development of a new class of drugs against the human filarial parasites. PMID:27300294

  5. The Geological Record of Parasitic Nematode Evolution.

    PubMed

    Poinar, George O

    2015-01-01

    This chapter discusses the evolutionary history of nematode parasites of invertebrates, vertebrates and plants based on fossil remains in amber, stone and coprolites dating from the Palaeozoic to the Holocene. The earliest parasitic nematode is a primitive plant parasite from the Devonian. Fossil invertebrate-parasitic nematodes first appeared in the Early Cretaceous, while the earliest fossil vertebrate-parasitic nematodes are from Upper Triassic coprolites. Specific examples of fossil nematode parasites over time are presented, along with views on the origin and evolution of nematodes and their hosts. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2015-08-01

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

  7. Nematode Indicators of Organic Enrichment

    PubMed Central

    Ferris, Howard; Bongers, Tom

    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 some microarthropods, are entry-level indicators of enrichment. However, the quantification of abundance and biomass of this diverse group, as an indicator of resource status, requires a plethora of extraction and assessment techniques. Soluble organic compounds are absorbed by bacteria and fungi, while fungi also degrade more recalcitrant sources. These organisms are potential indicators of the nature of incoming substrate, but current methods of biomass determination do not reliably indicate their community composition. Guilds of nematodes that feed on bacteria (e.g., Rhabditidae, Panagrolaimidae) and fungi (e.g., Aphelenchidae, Aphelenchoididae) are responsive to changes in abundance of their food. Through direct herbivory, plant-feeding nematodes (e.g., many species of Tylenchina) also contribute to food web resources. Thus, analysis of the nematode community of a single sample provides indication of carbon flow through an important herbivore channel and through channels mediated by bacteria and fungi. Some nematode guilds are more responsive than others to resource enrichment. Generally, those bacterivores with short lifecycles and high reproductive potential (e.g., Rhabditidae) most closely mirror the bloom of bacteria or respond most rapidly to active plant growth. The feeding habits of some groups remain unclear. For example, nematodes of the Tylenchidae may constitute 30% or more of the individuals in a soil sample; further study is necessary to determine which resource channels they portray and the appropriate level of taxonomic resolution for this group. A graphic representation of the relative biomass of bacterivorous, fungivorous, and herbivorous nematodes

  8. Altered Circulating Levels of Matrix Metalloproteinases and Inhibitors Associated with Elevated Type 2 Cytokines in Lymphatic Filarial Disease

    PubMed Central

    Anuradha, Rajamanickam; George, Jovvian P.; Pavankumar, Nathella; Kumaraswami, Vasanthapuram; Nutman, Thomas B.; Babu, Subash

    2012-01-01

    Background Infection with Wuchereria bancrofti can cause severe disease characterized by subcutaneous fibrosis and extracellular matrix remodeling. Matrix metalloproteinases (MMPs) are a family of enzymes governing extracellular remodeling by regulating cellular homeostasis, inflammation, and tissue reorganization, while tissue-inhibitors of metalloproteinases (TIMPs) are endogenous regulators of MMPs. Homeostatic as well as inflammation-induced balance between MMPs and TIMPs is considered critical in mediating tissue pathology. Methods To elucidate the role of MMPs and TIMPs in filarial pathology, we compared the plasma levels of a panel of MMPs, TIMPs, other pro-fibrotic factors, and cytokines in individuals with chronic filarial pathology with (CP Ag+) or without (CP Ag−) active infection to those with clinically asymptomatic infections (INF) and in those without infection (endemic normal [EN]). Markers of pathogenesis were delineated based on comparisons between the two actively infected groups (CP Ag+ compared to INF) and those without active infection (CP Ag− compared to EN). Results and Conclusion Our data reveal that an increase in circulating levels of MMPs and TIMPs is characteristic of the filarial disease process per se and not of active infection; however, filarial disease with active infection is specifically associated with increased ratios of MMP1/TIMP4 and MMP8/TIMP4 as well as with pro-fibrotic cytokines (IL-5, IL-13 and TGF-β). Our data therefore suggest that while filarial lymphatic disease is characterized by a non-specific increase in plasma MMPs and TIMPs, the balance between MMPs and TIMPs is an important factor in regulating tissue pathology during active infection. PMID:22679524

  9. Basic and applied research: Entomopathogenic nematodes

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes in the genera Heterorhabditis and Steinernema kill arthropods with the aid of their bacterial symbionts. These nematodes are potent microbial control agents that have been widely commercialized for control of economically important insect pests. Biocontrol efficacy relies...

  10. Nematode neuropeptides as transgenic nematicides

    PubMed Central

    Patten, Cheryl; Fleming, Colin C.; Maule, Aaron G.

    2017-01-01

    Plant parasitic nematodes (PPNs) seriously threaten global food security. Conventionally an integrated approach to PPN management has relied heavily on carbamate, organophosphate and fumigant nematicides which are now being withdrawn over environmental health and safety concerns. This progressive withdrawal has left a significant shortcoming in our ability to manage these economically important parasites, and highlights the need for novel and robust control methods. Nematodes can assimilate exogenous peptides through retrograde transport along the chemosensory amphid neurons. Peptides can accumulate within cells of the central nerve ring and can elicit physiological effects when released to interact with receptors on adjoining cells. We have profiled bioactive neuropeptides from the neuropeptide-like protein (NLP) family of PPNs as novel nematicides, and have identified numerous discrete NLPs that negatively impact chemosensation, host invasion and stylet thrusting of the root knot nematode Meloidogyne incognita and the potato cyst nematode Globodera pallida. Transgenic secretion of these peptides from the rhizobacterium, Bacillus subtilis, and the terrestrial microalgae Chlamydomonas reinhardtii reduce tomato infection levels by up to 90% when compared with controls. These data pave the way for the exploitation of nematode neuropeptides as a novel class of plant protective nematicide, using novel non-food transgenic delivery systems which could be deployed on farmer-preferred cultivars. PMID:28241060

  11. Application and commercialization of nematodes.

    PubMed

    Peters, Arne

    2013-07-01

    While nematodes are most commonly known for their negative impact on plants, animals, and humans, there are a number of species which are commercially explored. This review highlights some of the most important success stories for the application of nematodes. They are used as bioindicators in ecological and toxicity studies, as model organisms for elucidating fundamental biological questions and for high throughput screening of drugs. Besides these indirect uses, direct applications include the use of Beddingia siricidicola against a major forest pest and the commercialization of Steinernema, Heterorhabditis, and Phasmarhabditis as biological pest control products. New directions for the commercialization of nematodes are the use as living food, specifically loaded with essential nutrients for various fish and shrimp larvae. Even human parasites or closely related species have been successfully used for curing autoimmune disorders and are currently in the process of being developed as drugs. With the striving development of life sciences, we are likely to see more applications for nematodes in the future. A prerequisite is that we continue to explore the vast number of yet undiscovered nematode species.

  12. Nematode neuropeptides as transgenic nematicides.

    PubMed

    Warnock, Neil D; Wilson, Leonie; Patten, Cheryl; Fleming, Colin C; Maule, Aaron G; Dalzell, Johnathan J

    2017-02-01

    Plant parasitic nematodes (PPNs) seriously threaten global food security. Conventionally an integrated approach to PPN management has relied heavily on carbamate, organophosphate and fumigant nematicides which are now being withdrawn over environmental health and safety concerns. This progressive withdrawal has left a significant shortcoming in our ability to manage these economically important parasites, and highlights the need for novel and robust control methods. Nematodes can assimilate exogenous peptides through retrograde transport along the chemosensory amphid neurons. Peptides can accumulate within cells of the central nerve ring and can elicit physiological effects when released to interact with receptors on adjoining cells. We have profiled bioactive neuropeptides from the neuropeptide-like protein (NLP) family of PPNs as novel nematicides, and have identified numerous discrete NLPs that negatively impact chemosensation, host invasion and stylet thrusting of the root knot nematode Meloidogyne incognita and the potato cyst nematode Globodera pallida. Transgenic secretion of these peptides from the rhizobacterium, Bacillus subtilis, and the terrestrial microalgae Chlamydomonas reinhardtii reduce tomato infection levels by up to 90% when compared with controls. These data pave the way for the exploitation of nematode neuropeptides as a novel class of plant protective nematicide, using novel non-food transgenic delivery systems which could be deployed on farmer-preferred cultivars.

  13. Macrophage migration inhibitory factor of the parasitic nematode Trichinella spiralis.

    PubMed Central

    Tan, T H; Edgerton, S A; Kumari, R; McAlister, M S; Roe, S M; Nagl, S; Pearl, L H; Selkirk, M E; Bianco, A E; Totty, N F; Engwerda, C; Gray, C A; Meyer, D J; Rowe, S M

    2001-01-01

    cDNAs were obtained for macrophage migration-inhibitory factor (MIF)/L-dopachrome methyl ester tautomerase homologues from the parasitic nematodes Trichinella spiralis (TsMIF) and Trichuris trichiura (TtMIF). The translated sequences, which were partly confirmed by sequencing of proteolytic fragments, show 42 and 44% identity respectively with human or mouse MIF, and are shorter by one C-terminal residue. Unlike vertebrate MIF and MIF homologues of filarial nematodes, neither TsMIF nor TtMIF contain cysteine residues. Soluble recombinant TsMIF, expressed in Escherichia coli showed secondary structure (by CD spectroscopy) and quaternary structure (by light-scattering and gel filtration) similar to that of the trimeric mammalian MIFs and D-dopachrome tautomerase. The catalytic specificity of recombinant TsMIF in the ketonization of phenylpyruvate (1.4x10(6) M(-1) x s(-1)) was comparable with that of human MIF, while that of p-hydroxyphenylpyruvate (9.1x10(4) M(-1) x s(-1)) was 71-fold lower. TsMIF showed high specificity in tautomerization of the methyl ester of L-dopachrome compared with non-esterified L-dopachrome (>87000-fold) and a high kcat (approximately 4x10(4) s(-1). The crystal structure, determined to 1.65 A (1 A=0.1 nm), was generally similar to that of human MIF, but differed in the boundaries of the putative active-site pocket, which can explain the low activity towards p-hydroxyphenylpyruvate. The central pore was blocked, but was continuous, with the three putative tautomerase sites. Recombinant TsMIF (5 ng/ml-5 pg/ml) inhibited migration of human peripheral-blood mononuclear cells in a manner similar to that shown by human MIF, but had no effect from 5 to 500 ng/ml on anti-CD3-stimulated murine T-cell proliferation. TsMIF was detected in supernatants of T. spiralis larvae cultured in vitro at 6 ng/ml (55 ng/mg total secreted protein). In conclusion TsMIF has structural, catalytic and cell-migration-inhibitory properties which indicate that it is

  14. Impact of conservation tillage on nematode populations.

    PubMed

    Minton, N A

    1986-04-01

    Literature reporting the development of conservation tillage and the research that has been conducted on nematode control in crops grown in conservation tillage systems is reviewed. Effects of different types of conservation tillage on population densities of various nematode species in monocropping and multicropping systems, effects of tillage on nematode distribution in the soil profile, effects of conservation tillage on nematode control, and the role of nematology in conservation tillage research are discussed.

  15. Treatment of filarial lymphoedema and elephantiasis with 5,6-benzo-alpha-pyrone (coumarin).

    PubMed Central

    Casley-Smith, J R; Wang, C T; Casley-Smith, J R; Zi-hai, C

    1993-01-01

    OBJECTIVE--To study efficacy of treatment of filarial lymphoedema and elephantiasis with 5,6-benzo-alpha-pyrone. DESIGN--Randomised, double blind, placebo controlled study with matching for grade and duration of disease, age, and sex. Treatment was given for 367 days, and subjects were followed up for another year. SETTING--A town in Shandong Province, China. SUBJECTS--104 men and women with chronic unilateral filarial lymphoedema or elephantiasis of the leg: 64 were randomised to benzopyrone and 40 to placebo. By the end of the study 19 patients had dropped out of the treatment group and two out of the placebo group. INTERVENTIONS--Two 200 mg tablets of 5,6-benzo-alpha-pyrone or two placebo tablets given daily. MAIN OUTCOME MEASURES--Volumes of the affected and normal legs estimated every three months, and daily listing of any side effects. RESULTS--Benzopyrone reduced oedema for all grades of lymphoedema during the year of treatment (pW0.001) and the follow up year (p = 0.026). During treatment the mean monthly reductions in leg volume were 0.62% (95% confidence intervals 0.4% to 0.85%), 1.1% (0.71% to 1.6%), and 1.6% (0.89% to 2.3%) of the volume of the normal leg for grades 1, 2, and 3-5 (elephantiasis) of lymphoedema respectively. During follow up the mean monthly reductions were 0.18% (0.01% to 0.35%), 0.54% (0.27% to 0.82%), and 0.87% (0.51% to 1.2%). At the end of the trial the total reduction in oedema was 100%, 95%, and 45% for grades 1, 2, and 3-5. Symptoms and complications were considerably reduced, including attacks of secondary acute inflammation, while side effects were minor and disappeared after one month. In the placebo group there were no changes in the severity of lymphoedema. CONCLUSIONS--5,6-benzo-alpha-pyrone reduces the oedema and many symptoms of filarial lymphoedema and elephantiasis. It has few side effects, and its relatively slow action makes it ideal for use without compression garments. PMID:8251778

  16. Using entomopathogenic nematodes for crop insect control

    USDA-ARS?s Scientific Manuscript database

    The objective of this paper is to provide an overview on using entomopathogenic nematodes for insect pest control. Entomopathogenic nematodes (genera Steinernema and Heterorhabditis), are be used as natural biopesticides. Unlike plant parasitic nematodes, which can be serious crop pests, entomopat...

  17. In vivo production of entomopathogenic nematodes

    USDA-ARS?s Scientific Manuscript database

    In nature, entomopathogenic nematodes in the genera Heterorhabditis and Steinernema are obligate parasites of insects. The nematodes are used widely as biocontrol agents for insect pests. More than a dozen entomopathogenic nematode species have been commercialized for use as biopesticides. One of ...

  18. Therapeutic immunomodulators from nematode parasites.

    PubMed

    Harnett, William; Harnett, Margaret M

    2008-06-19

    There has been an alarming increase in the incidence of autoimmune and allergic diseases in Western countries in the past few decades. However, in countries endemic for parasitic helminth infections, such diseases remain relatively rare. Hence, it has been hypothesised that helminths may protect against the development of autoimmunity and allergy. This article reviews the evidence supporting this idea with respect to helminths of the phylum Nematoda (nematodes), considering data from human studies and animal models of inflammatory disease. The nature and mode of action of nematode-derived molecules with immunomodulatory properties are considered, and their therapeutic efficacy in models of autoimmunity and allergy described. The recent and future use of nematodes and their products in treating human disease are also discussed.

  19. The larval specific lymphatic filarial ALT-2: induction of protection using protein or DNA vaccination.

    PubMed

    Ramachandran, Sabarinathan; Kumar, Mishra Pankaj; Rami, Reddy Maryada Venkata; Chinnaiah, Harinath Basker; Nutman, Thomas; Kaliraj, Perumal; McCarthy, James

    2004-01-01

    Genes from the infective stage of lymphatic filarial parasites expressed at the time of host invasion have been identified as potential vaccine candidates. By screening an L3 cDNA library with sera from uninfected longstanding residents of an area endemic for onchocerciasis, so-called "endemic normals" (EN), we have cloned and characterized one such gene termed the abundant larval transcript two (ALT-2). The stage specificity of ALT-2 gene transcription and protein synthesis was confirmed by PCR using genespecific primers, and by western blot analysis of protein extracts from various stages of the parasite life cycle using specific antisera. Significant differences in antibody response to the recombinant ALT-2 were observed in endemic populations with differing clinical manifestations of lymphatic filariasis with an antibody response present in sera from 18 of 25 (72%) EN subjects compared to 9 of 25 (36%) with subclinical microfilaracmia (MF) and 14 of 25 (52%) of those with chronic lymphatic obstruction (CP) (P=0.01 for comparison of EN to CP or to MF). This differential responsiveness suggests that the protective immunity postulated to account for their uninfected status might be associated with a response to this protein. When the utility of ALT-2 as a vaccine candidate was tested in a murine model using either recombinant protein or a DNA vaccine construct, statistically significant protection was observed when compared to a control filarial gene product expressed across all stages of the parasite lifecycle (SXP-1; P=0.02 for protein and P=0.01 for the DNA vaccine) or compared to adjuvant alone. This level of protection indicates that this vaccine is a promising candidate for further development.

  20. Molecular detection of Setaria tundra (Nematoda: Filarioidea) and an unidentified filarial species in mosquitoes in Germany

    PubMed Central

    2012-01-01

    Background Knowledge of the potential vector role of Culicidae mosquitoes in Germany is very scanty, and until recently it was generally assumed that they are not involved in the transmission of anthroponotic or zoonotic pathogens in this country. However, anticipated changes in the course of global warming and globalization may alter their status. Methods We conducted a molecular mass screening of mosquitoes for filarial parasites using mitochondrial 12S rRNA-based real-time PCR. Results No parasites causing disease in humans such as Dirofilaria spp. were detected in about 83,000 mosquitoes tested, which had been collected in 2009 and 2010 in 16 locations throughout Germany. However, minimum infection rates of up to 24 per 1000 mosquitoes were revealed, which could be attributed to mosquito infection with Setaria tundra and a yet unidentified second parasite. Setaria tundra was found to be widespread in southern Germany in various mosquito species, except Culex spp. In contrast, the unidentified filarial species was exclusively found in Culex spp. in northern Baden-Württemberg, and is likely to be a bird parasite. Conclusions Although dirofilariasis appears to be emerging and spreading in Europe, the absence of Dirofilaria spp. or other zoonotic filariae in our sample allows the conclusion that the risk of autochthonous infection in Germany is still very low. Potential vectors of S. tundra in Germany are Ochlerotatus sticticus, Oc. cantans, Aedes vexans and Anopheles claviger. Technically, the synergism between entomologists, virologists and parasitologists, combined with state-of-the-art methods allows a very efficient near-real-time monitoring of a wide spectrum of both human and veterinary pathogens, including new distribution records of parasite species and the incrimination of their potential vectors. PMID:22236560

  1. Immunomodulatory effect of diethylcarbamazine citrate plus filarial excretory-secretory product on rat hepatocarcinogenesis.

    PubMed

    Abdel-Latif, Mahmoud; Sakran, Thabet; El-Shahawi, Gamal; El-Fayoumi, Hoda; El-Mallah, Al-Mahy

    2015-02-01

    Diethylcarbamazine citrate (DEC) had a significance in anti-filarial chemotherapy, while excretory-secretory product (ES) is released from adult filarial females. The target of the current study was to examine the immunomodulatory effect of DEC, Setaria equina ES or a combination of them on rat hepatocellular carcinoma (HCC) induced by diethylnitrosamine (DEN). In vitro effect of combined DEC and ES or ES alone on lipopolysaccharide (LPS)-stimulated rat peripheral blood mononuclear cells (PBMCs) was tested through IFN-γ assay in culture supernatants. In addition, single or repeated doses of DEC, ES or DEC+ES have been applied in white albino rats to test the effect on HCC. Levels of IFN-γ and anti-ES IgG antibodies in rat serum were assayed using ELISA. Hemolytic complement activity (CH50) was determined in serum while the concentration of nitric oxide (NO) was assayed in liver tissue. The infiltration of NK cells as well as the expression of MHC Iproliferating cell nuclear antigen (PCNA), inducible NO synthase (iNOS), Bcl2 and p53 were determined using immunohistochemistry. There was a dose-dependent increase in IFN-γ after in vitro exposure to DEC+ES. Repeated ES doses increased NO concentration (p<0.05) and expression of iNOS but reduced CH50 (p<0.001), while repeated DEC+ES doses could increase anti-ES IgG (p<0.01), IFN-γ level (p<0.05) and NK cell infiltration. The same treatments could also reduce the expression of MHC I expression, PCNA, Bcl2 and p53. This study has shown immunomodulatory and protective effects of DEC+ES repeated doses on rat HCC.

  2. Cloning of a cuticular antigen that contains multiple tandem repeats from the filarial parasite Dirofilaria immitis.

    PubMed Central

    Poole, C B; Grandea, A G; Maina, C V; Jenkins, R E; Selkirk, M E; McReynolds, L A

    1992-01-01

    An unusual antigen composed of tandemly repeated protein units was cloned from the filarial parasite Dirofilaria immitis. The antigen was initially identified by screening a lambda gt11 cDNA library with serum from dogs immunized with irradiated D. immitis third-stage larvae. DNA sequence analysis of the cDNA clone, Di5, revealed a continuous open reading frame composed of two 399-base-pair repeats arranged in tandem. Southern blot analysis of genomic D. immitis DNA showed that the gene coding for Di5 is composed of a tandem array of 25-50 copies of this same 399-base-pair repeat. Antiserum raised against recombinant Di5 protein detected a protein "ladder," from about 14 to greater than 200 kDa with steps approximately 15 kDa apart, on immunoblots of D. immitis extract. Metabolic labeling of adult parasites with [35S]methionine showed that Di5 is synthesized as a large precursor that is subsequently cleaved to produce the ladder-like array. These results suggest that the characteristic ladder is created by proteolytic cleavage of the precursor at the same site in each monomer. The Di5 antigen was localized to the cuticle and hypodermis of adult D. immitis by immunoelectron microscopy. Both male and female parasites were found to release Di5 when cultured in vitro. DNA hybridization analysis demonstrated that Di5 is a member of a gene family present in many filarial parasites that infect both animal and human populations. Images PMID:1631084

  3. Maternal Filarial Infection Influences the Development of Regulatory T Cells in Children from Infancy to Early Childhood

    PubMed Central

    Bal, Madhusmita; Ranjit, Manoranjan; Achary, K. Gopinath; Satapathy, Ashok K.

    2016-01-01

    Background Children born from filarial infected mothers are comparatively more susceptible to filarial infection than the children born to uninfected mothers. But the mechanism of such increased susceptibility to infection in early childhood is not exactly known. Several studies have shown the association of active filarial infection with T cell hypo-responsiveness which is mediated by regulatory T cells (Tregs). Since the Tregs develop in the thymus from CD4+ CD25hi thymocytes at an early stage of the human fetus, it can be hypothesized that the maternal infection during pregnancy affects the development of Tregs in children at birth as well as early childhood. Hence the present study was designed to test the hypothesis by selecting a cohort of pregnant mothers and children born to them subsequently in a filarial endemic area of Odisha, India. Methodology and Principal finding A total number of 49 pregnant mothers and children born to them subsequently have been followed up (mean duration 4.4 years) in an area where the microfilariae (Mf) rate has come down to <1% after institution of 10 rounds of annual mass drug administration (MDA). The infection status of mother, cord and children were assessed through detection of microfilariae (Mf) and circulating filarial antigen (CFA). Expression of Tregs cells were measured by flow cytometry. The levels of IL-10 were evaluated by using commercially available ELISA kit. A significantly high level of IL-10 and Tregs have been observed in children born to infected mother compared to children of uninfected mother at the time of birth as well as during early childhood. Moreover a positive correlation between Tregs and IL-10 has been observed among the children born to infected mother. Significance From these observations we predict that early priming of the fetal immune system by filarial antigens modulate the development of Tregs, which ultimately scale up the production of IL-10 in neonates and creates a milieu for high rate

  4. Maternal Filarial Infection Influences the Development of Regulatory T Cells in Children from Infancy to Early Childhood.

    PubMed

    Bal, Madhusmita; Ranjit, Manoranjan; Achary, K Gopinath; Satapathy, Ashok K

    2016-11-01

    Children born from filarial infected mothers are comparatively more susceptible to filarial infection than the children born to uninfected mothers. But the mechanism of such increased susceptibility to infection in early childhood is not exactly known. Several studies have shown the association of active filarial infection with T cell hypo-responsiveness which is mediated by regulatory T cells (Tregs). Since the Tregs develop in the thymus from CD4+ CD25hi thymocytes at an early stage of the human fetus, it can be hypothesized that the maternal infection during pregnancy affects the development of Tregs in children at birth as well as early childhood. Hence the present study was designed to test the hypothesis by selecting a cohort of pregnant mothers and children born to them subsequently in a filarial endemic area of Odisha, India. A total number of 49 pregnant mothers and children born to them subsequently have been followed up (mean duration 4.4 years) in an area where the microfilariae (Mf) rate has come down to <1% after institution of 10 rounds of annual mass drug administration (MDA). The infection status of mother, cord and children were assessed through detection of microfilariae (Mf) and circulating filarial antigen (CFA). Expression of Tregs cells were measured by flow cytometry. The levels of IL-10 were evaluated by using commercially available ELISA kit. A significantly high level of IL-10 and Tregs have been observed in children born to infected mother compared to children of uninfected mother at the time of birth as well as during early childhood. Moreover a positive correlation between Tregs and IL-10 has been observed among the children born to infected mother. From these observations we predict that early priming of the fetal immune system by filarial antigens modulate the development of Tregs, which ultimately scale up the production of IL-10 in neonates and creates a milieu for high rate of acquisition of infection in children born to infected

  5. The effect of HIV on filarial-specific antibody response before and after treatment with diethylcarbamazine in Wuchereria bancrofti infected individuals.

    PubMed

    Petersen, Heidi H; Nielsen, Nina O; Monrad, Jesper; Magesa, Stephen M; Simonsen, Paul E

    2009-06-01

    The effect of HIV on filarial-specific antibody response before and after treatment with diethylcarbamazine (DEC) was analysed by comparing two groups of Wuchereria bancrofti-infected adult individuals (positive for circulating filarial antigen) who were positive (n=15) or negative (n=21) for HIV co-infection. Prior to DEC treatment there was no significant difference in filarial-specific IgG1, IgG2, IgG4 and IgE antibody response between the HIV negative and the HIV positive group, while a five times (statistically significant) higher filarial-specific IgG3 response was observed in the HIV positive than in the HIV negative group. At 12 weeks after treatment with DEC, a significant decrease in filarial-specific IgG4 was observed in the HIV positive but not in the HIV negative group, indicating that DEC treatment had a stronger antifilarial effect in individuals co-infected with HIV. DEC treatment had no significant effect on the other classes of filarial specific antibodies, neither in the HIV negative or the HIV positive group.

  6. Nonhost Root Penetration by Soybean Cyst Nematode

    PubMed Central

    Riggs, R. D.

    1987-01-01

    A total of 66 plants in 50 species were inoculated with eggs and juveniles of soybean cyst nematode, Heterodera glycines. Roots were stained and observed for penetration and development of the nematode. Twenty-six plants were not penetrated; twenty-three were penetrated, but there was no development of the nematode; eight were penetrated with some nematode development; two were penetrated and had considerable nematode development, but few nematodes, if any, matured; and seven were penetrated with many nematodes maturing. The penetration of nonhosts may imply some susceptibility and that populations eventually would build up on the penetrated plants. Plants not penetrated may be useful as rotation plants because no reproduction would occur. PMID:19290137

  7. Compatibility of soil amendments with entomopathogenic nematodes.

    PubMed

    Bednarek, A; Gaugler, R

    1997-06-01

    The impact of inorganic and organic fertilizers on the infectivity, reproduction, and population dynamics of entomopathogenic nematodes was investigated. Prolonged (10- to 20-day) laboratory exposure to high inorganic fertilizer concentrations inhibited nematode infectivity and reproduction, whereas short (1-day) exposures increased infectivity. Heterorhabditis bacteriophora was more sensitive to adverse effects than were two species of Steinernema. In field studies, organic manure resulted in increased densities of a native population of Steinernema feltiae, whereas NPK fertilizer suppressed nematode densities regardless of manure applications. Inorganic fertilizers are likely to be compatible with nematodes in tank mixes and should not reduce the effectiveness of nematodes used for short-term control as biological insecticides, but may interfere with attempts to use nematodes as inoculative agents for long-term control. Organic manure used as fertilizer may encourage nematode establishment and recycling.

  8. Free-living nematode peptides

    USDA-ARS?s Scientific Manuscript database

    All nematodes employ a wide array of peptide messengers to control nearly all aspects of the life cycle, including hatching, locomotion, feeding, defense, mating, reproduction, and other behavioral and metabolic events. There are molecular and biological similarities, as well as significant differen...

  9. Nematode Symbiont for Photorhabdus asymbiotica

    PubMed Central

    Joyce, Susan A.; Clarke, David J.; ffrench-Constant, Richard H.; Nimmo, Graeme R.; Looke, David F.M.; Feil, Edward J.; Pearce, Lucy; Waterfield, Nick R.

    2006-01-01

    Photorhabdus asymbiotica is an emerging bacterial pathogen that causes locally invasive soft tissue and disseminated bacteremic infections in the United States and Australia. Although the source of infection was previously unknown, we report that the bacterium is found in a symbiotic association with an insect-pathogenic soil nematode of the genus Heterorhabditis. PMID:17176572

  10. Impact of single dose of diethylcarbamazine and other antifilarial drug combinations on bancroftian filarial infection variables: assessment after 2 years.

    PubMed

    Sunish, I P; Rajendran, R; Mani, T R; Munirathinam, A; Reuben, R; Dash, A P

    2006-09-01

    The impact of single dose mass drug administration of diethylcarbamazine (DEC), DEC with albendazole (ALB), and ivermectin (IVR) with albendazole, was examined on the human bancroftian filarial infections in village scale trials in south India, from a follow-up study after 2 years. The treatment arms administered with DEC alone and DEC+ALB demonstrated long-term benefits in reducing microfilaraemia significantly (P<0.05), while antigenaemia reduction was negligible. The arm with ALB+IVR did not show such reductions. Among the antigenaemic and microfilaraemic individuals, 87% became amicrofilaraemic in DEC+ALB arm, which were higher than that observed in the other 2 treatment arms. Among amicrofilaraemics (but Ag+), nearly 35% cleared of infection in DEC+ALB, while 26% and 6% in DEC alone and IVR+ALB arms, respectively. The drug combination DEC+ALB was observed to demonstrate a significant impact in reducing filarial infection even after 2 years post treatment.

  11. Maternal filarial infection: association of anti-sheath antibody responses with plasma levels of IFN-γ and IL-10.

    PubMed

    Achary, K G; Mandal, N N; Mishra, S; Sarangi, S S; Kar, S K; Satapathy, A K; Bal, M S

    2013-04-01

    Maternal filarial infection influences the risk of acquiring infection and development of immunity in children. Here we have analysed the blood samples of 60 mothers (24 infected and 36 uninfected) and their corresponding cord bloods to assess the impact of maternal infection on the anti-sheath antibodies and cytokine production in neonates born from them. About 69·4% of non-infected mothers and their cord bloods showed the presence of anti-sheath antibodies, while only 16·6% of the cord bloods from infected mothers were positive for it. The IL-10 level was significantly high in cord bloods of infected mothers compared with non-infected mothers. At the same time the IL-10 level was also observed to be remarkably high in cord bloods of both infected and non-infected mothers negative for anti-sheath antibody. In contrast, IFN-γ levels were significantly high in cord bloods of non-infected mothers compared with infected mothers and the increment was prominent in cord bloods of both infected and non-infected mothers positive for anti-sheath antibody. The study reveals that the presence or absence of anti-sheath antibodies in association with cytokines skews the filarial specific immunity to either Th1 or Th2 responses in neonates. This may affect the natural history of filarial infection in early childhood.

  12. Parasitological, serological and clinical evidence for high prevalence of podoconiosis (non-filarial elephantiasis) in Midakegn district, central Ethiopia.

    PubMed

    Geshere Oli, Geleta; Tekola Ayele, Fasil; Petros, Beyene

    2012-06-01

    To determine whether the elephantiasis in Midakegn district, central Ethiopia, is filarial or non-filarial (podoconiosis) using serological, parasitological and clinical examinations, and to estimate its prevalence. At house-to-house visits in 330 randomly selected households, all household members who had elephantiasis were interviewed and clinically examined at the nearby health centre to confirm the presence of elephantiasis, check the presence of scrotal swelling and rule out the other causes of lymphoedema. A midnight blood sample was obtained from each participant with elephantiasis for microscopic examination of Wuchereria bancrofti microfilaria. A daytime blood sample was obtained from half of the participants for serological confirmation using the immuno-chromatographic test card. Consistent with the features of podoconiosis, none of the elephantiasis cases had consistently worn shoes since childhood; 94.3% had bilateral swelling limited below the level of the knees; no individual had thigh or scrotal elephantiasis; parasitological test for microfilariae and serological tests for W. bancrofti antigen were negative in all samples. The prevalence of the disease was 7.4% and it peaked in the third decade of life, the most economically active age. Midakegn District has a high prevalence of podoconiosis and no filarial elephantiasis. Prevention, treatment and control of podoconiosis must be among the top priorities of public health programmes. © 2012 Blackwell Publishing Ltd.

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

    PubMed

    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.

  14. Nematode.net: a tool for navigating sequences from parasitic and free-living nematodes

    PubMed Central

    Wylie, Todd; Martin, John C.; Dante, Michael; Mitreva, Makedonka Dautova; Clifton, Sandra W.; Chinwalla, Asif; Waterston, Robert H.; Wilson, Richard K.; McCarter, James P.

    2004-01-01

    Nematode.net (www.nematode.net) is a web- accessible resource for investigating gene sequences from nematode genomes. The database is an outgrowth of the parasitic nematode EST project at Washington University’s Genome Sequencing Center (GSC), St Louis. A sister project at the University of Edinburgh and the Sanger Institute is also underway. More than 295 000 ESTs have been generated from >30 nematodes other than Caenorhabditis elegans including key parasites of humans, animals and plants. Nematode.net currently provides NemaGene EST cluster consensus sequence, enhanced online BLAST search tools, functional classifications of cluster sequences and comprehensive information concerning the ongoing generation of nematode genome data. The long-term goal of nematode.net is to provide the scientific community with the highest quality sequence information and tools for studying these diverse species. PMID:14681448

  15. Detection of plant-parasitic nematode DNA in the gut of predatory and omnivorous nematodes

    USDA-ARS?s Scientific Manuscript database

    A protocol for molecular gut analysis of nematodes was developed to determine if predatory and omnivorous nematodes from five different guilds prey on Rotylenchulus reniformis, Meloidogyne incognita, and Radopholus similis. Mononchoides, Mononchus, Neoactinolaimus, Mesodorylaimus, and Aporcelaimell...

  16. A Mechanism for Chronic Filarial Hydrocele with Implications for Its Surgical Repair

    PubMed Central

    Norões, Joaquim; Dreyer, Gerusa

    2010-01-01

    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 30.3yr and mean follow-up of 8.6yr [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 25.1yr and mean follow-up of 6yr [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

  17. Filarial infection modulates the immune response to Mycobacterium tuberculosis through expansion of CD4+ IL-4 memory T cells.

    PubMed

    Chatterjee, Soumya; Clark, Carolyn E; Lugli, Enrico; Roederer, Mario; Nutman, Thomas B

    2015-03-15

    Exaggerated CD4(+) T helper 2-specific cytokine producing memory T cell responses developing concomitantly with a T helper 1 response might have a detrimental role in immunity to infection caused by Mycobacterium tuberculosis. To assess the dynamics of Ag-specific memory T cell compartments in the context of filarial infection, we used multiparameter flow cytometry on PBMCs from 25 microfilaremic filarial-infected (Inf) and 14 filarial-uninfected (Uninf) subjects following stimulation with filarial Ag (BmA) or with the M. tuberculosis-specific Ag culture filtrate protein-10 (CFP-10). Our data demonstrated that the Inf group had a marked increase in BmA-specific CD4(+)IL-4(+) cells (median net frequency compared with baseline [Fo] = 0.09% versus 0.01%; p = 0.038) but also to CFP-10 (Fo = 0.16% versus 0.007%; p = 0.04) and staphylococcal enterotoxin B (Fo = 0.49% versus 0.26%; p = 0.04). The Inf subjects showed a BmA-specific expansion of CD4(+)CD45RO(+)IL-4(+) producing central memory (TCM, CD45RO(+)CCR7(+)CD27(+); Fo = 1.1% versus 0.5%; p = 0.04) as well as effector memory (TEM, CD45RO(+)CCR7(-)CD27(-); Fo = 1.5% versus 0.2%; p = 0.03) with a similar but nonsignificant response to CFP-10. In addition, there was expansion of CD4(+)IL-4(+)CD45RA(+)CCR7(+)CD27(+) (naive-like) in Inf individuals compared with Uninf subjects. Among Inf subjects with definitive latent tuberculosis, there were no differences in frequencies of IL-4-producing cells within any of the memory compartments compared with the Uninf group. Our data suggest that filarial infection induces Ag-specific, exaggerated IL-4 responses in distinct T cell memory compartments to M. tuberculosis-specific Ags, which are attenuated in subjects who are able to mount a delayed type hypersensitivity reaction to M. tuberculosis.

  18. Filarial infection modulates the immune response to Mycobacterium tuberculosis through expansion of CD4+ IL-4 memory T cells

    PubMed Central

    Chatterjee, Soumya; Clark, Carolyn E.; Lugli, Enrico; Roederer, Mario; Nutman, Thomas B.

    2015-01-01

    Exaggerated CD4+T helper 2-specific cytokine producing memory T cell responses developing concomitantly with a T helper1 response might have a detrimental role in immunity to infection caused by Mycobacterium tuberculosis (Mtb). To assess the dynamics of antigen (Ag)-specific memory T cell compartments in the context of filarial infection we used multiparameter flow cytometry on PBMCs from 25 microfilaremic filarial -infected (Inf) and 14 filarial-uninfected (Uninf) subjects following stimulation with filarial (BmA) or with the Mycobacterium tuberculosis (Mtb)-specific Ag CFP10. Our data demonstrated that the Inf group not only had a marked increase in BmA-specific CD4+IL-4+ cells (Median net frequency compared to baseline (Fo)=0.09% vs. 0.01%, p=0.038) but also to CFP10 (Fo =0.16% vs. 0.007%, p=0.04) and Staphylococcal Enterotoxin B (SEB) (Fo =0.49% vs. 0.26%, p=0.04). The Inf subjects showed a BmA-specific expansion of CD4+CD45RO+IL-4+ producing central memory (TCM, CD45RO+CCR7+CD27+) (Fo =1.1% vs. 0.5%, p=0.04) as well as effector memory (TEM CD45RO+CCR7-CD27-) (Fo =1.5% vs. 0.2%, p=0.03) with a similar but non-significant response to CFP10. In addition, there was expansion of CD4+ IL-4+ CD45RA+ CCR7+CD27+ (naïve-like) in Inf individuals compared to Uninf subjects. Among Inf subjects with definitive latent tuberculosis , there were no differences in frequencies of IL-4 producing cells within any of the memory compartments compared to the Uninf group. Our data suggest that filarial infection induces antigen-specific, exaggerated IL-4 responses in distinct T cell memory compartments to Mtb-specific antigens, which are attenuated in subjects who are able to mount a delayed type hypersensitivity reaction to Mtb. PMID:25667413

  19. Experimental Evolution with Caenorhabditis Nematodes

    PubMed Central

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

    2017-01-01

    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. PMID:28592504

  20. Genome-wide survey and analysis of microsatellites in nematodes, with a focus on the plant-parasitic species Meloidogyne incognita

    PubMed Central

    2010-01-01

    Background Microsatellites are the most popular source of molecular markers for studying population genetic variation in eukaryotes. However, few data are currently available about their genomic distribution and abundance across the phylum Nematoda. The recent completion of the genomes of several nematode species, including Meloidogyne incognita, a major agricultural pest worldwide, now opens the way for a comparative survey and analysis of microsatellites in these organisms. Results Using MsatFinder, the total numbers of 1-6 bp perfect microsatellites detected in the complete genomes of five nematode species (Brugia malayi, Caenorhabditis elegans, M. hapla, M. incognita, Pristionchus pacificus) ranged from 2,842 to 61,547, and covered from 0.09 to 1.20% of the nematode genomes. Under our search criteria, the most common repeat motifs for each length class varied according to the different nematode species considered, with no obvious relation to the AT-richness of their genomes. Overall, (AT)n, (AG)n and (CT)n were the three most frequent dinucleotide microsatellite motifs found in the five genomes considered. Except for two motifs in P. pacificus, all the most frequent trinucleotide motifs were AT-rich, with (AAT)n and (ATT)n being the only common to the five nematode species. A particular attention was paid to the microsatellite content of the plant-parasitic species M. incognita. In this species, a repertoire of 4,880 microsatellite loci was identified, from which 2,183 appeared suitable to design markers for population genetic studies. Interestingly, 1,094 microsatellites were identified in 801 predicted protein-coding regions, 99% of them being trinucleotides. When compared against the InterPro domain database, 497 of these CDS were successfully annotated, and further assigned to Gene Ontology terms. Conclusions Contrasted patterns of microsatellite abundance and diversity were characterized in five nematode genomes, even in the case of two closely related

  1. Applying antibiotic selection markers for nematode genetics.

    PubMed

    Cornes, Eric; Quéré, Cécile A L; Giordano-Santini, Rosina; Dupuy, Denis

    2014-08-01

    Antibiotic selection markers have been recently developed in the multicellular model organism Caenorhabditis elegans and other related nematode species, opening great opportunities in the field of nematode transgenesis. Here we describe how these antibiotic selection systems can be easily combined with many well-established genetic approaches to study gene function, improving time- and cost-effectiveness of the nematode genetic toolbox. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Survey of Nematodes on Coffee in Hawaii

    PubMed Central

    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

  3. Ecology and evolution of soil nematode chemotaxis.

    PubMed

    Rasmann, Sergio; Ali, Jared Gregory; Helder, Johannes; van der Putten, Wim H

    2012-06-01

    Plants influence the behavior of and modify community composition of soil-dwelling organisms through the exudation of organic molecules. Given the chemical complexity of the soil matrix, soil-dwelling organisms have evolved the ability to detect and respond to these cues for successful foraging. A key question is how specific these responses are and how they may evolve. Here, we review and discuss the ecology and evolution of chemotaxis of soil nematodes. Soil nematodes are a group of diverse functional and taxonomic types, which may reveal a variety of responses. We predicted that nematodes of different feeding guilds use host-specific cues for chemotaxis. However, the examination of a comprehensive nematode phylogeny revealed that distantly related nematodes, and nematodes from different feeding guilds, can exploit the same signals for positive orientation. Carbon dioxide (CO(2)), which is ubiquitous in soil and indicates biological activity, is widely used as such a cue. The use of the same signals by a variety of species and species groups suggests that parts of the chemo-sensory machinery have remained highly conserved during the radiation of nematodes. However, besides CO(2), many other chemical compounds, belonging to different chemical classes, have been shown to induce chemotaxis in nematodes. Plants surrounded by a complex nematode community, including beneficial entomopathogenic nematodes, plant-parasitic nematodes, as well as microbial feeders, are thus under diffuse selection for producing specific molecules in the rhizosphere that maximize their fitness. However, it is largely unknown how selection may operate and how belowground signaling may evolve. Given the paucity of data for certain groups of nematodes, future work is needed to better understand the evolutionary mechanisms of communication between plant roots and soil biota.

  4. Preparation of nematodes for scanning electron microscopy.

    PubMed

    Green, C D; Stone, A R; Turner, R H; Clark, S A

    1975-01-01

    Nematodes from the orders Tlyenchida and Rhabditida were fixed and processed in several different ways for examination with the scanning electron microscope (SEM). Four processes produced good preparations of fixed nematodes. Drying from acetone was the simplest of these techniques and most useful for regions of the tylenchid nematodes supported by skeletal tissue. Critical point drying, a more complicated procedure, gave good preparations, but they required special care in processing. Nematodes infiltrated with glycerol and a conducting agent were the most life-like but were difficult to examine. Specimens infiltrated with an epoxy resin looked natural and this was the most promising process tried.

  5. Management of the Citrus Nematode, Tylenchulus semipenetrans

    PubMed Central

    Verdejo-Lucas, S.; McKenry, M. V.

    2004-01-01

    Of the many nematode species that parasitize citrus, Tylenchulus semipenetrans is the most important on a worldwide basis. Management of the citrus nematode remains problematic as no one tactic gives adequate control of the nematode. An overall management strategy must include such components as site selection, use of non-infected nursery stock, use of at lease one post-plant nematode control tactic, and careful management of other elements of the environment that may stress the trees. Nematicides continue to play a key role in management of this pest. Optimum results require careful attention to application techniques. PMID:19262822

  6. Comparative analysis of ITS1 nucleotide sequence reveals distinct genetic difference between Brugia malayi from Northeast Borneo and Thailand.

    PubMed

    Fong, Mun-Yik; Noordin, Rahmah; Lau, Yee-Ling; Cheong, Fei-Wen; Yunus, Muhammad Hafiznur; Idris, Zulkarnain Md

    2013-01-01

    Brugia malayi is one of the parasitic worms which causes lymphatic filariasis in humans. Its geographical distribution includes a large part of Asia. Despite its wide distribution, very little is known about the genetic variation and molecular epidemiology of this species. In this study, the internal transcribed spacer 1 (ITS1) nucleotide sequences of B. malayi from microfilaria-positive human blood samples in Northeast Borneo Island were determined, and compared with published ITS1 sequences of B. malayi isolated from cats and humans in Thailand. Multiple alignment analysis revealed that B. malayi ITS1 sequences from Northeast Borneo were more similar to each other than to those from Thailand. Phylogenetic trees inferred using Neighbour-Joining and Maximum Parsimony methods showed similar topology, with 2 distinct B. malayi clusters. The first cluster consisted of Northeast Borneo B. malayi isolates, whereas the second consisted of the Thailand isolates. The findings of this study suggest that B. malayi in Borneo Island has diverged significantly from those of mainland Asia, and this has implications for the diagnosis of B. malayi infection across the region using ITS1-based molecular techniques.

  7. Filaria-induced immune evasion: suppression by the infective stage of Brugia malayi at the earliest host-parasite interface.

    PubMed

    Semnani, Roshanak Tolouei; Law, Melissa; Kubofcik, Joseph; Nutman, Thomas B

    2004-05-15

    To assess the physiologic interactions between the infective stage of Brugia malayi--one of the extracellular parasites responsible for lymphatic filariasis in humans--and the APC with which they come in contact during their development and routes of travel, we have investigated the interaction between the infective stage (L3) of B. malayi and human Langerhans cells (LC) in the skin. Our data indicate that live L3 result in increased migration of LC from the epidermis without affecting the viability of these cells and up-regulation of the IL-18 cytokine involved in LC migration. Live L3 also result in down-regulation of MHC class I and II on the LC cell surface. Additionally, microarray data indicate that live L3 significantly down-regulated expression of IL-8 as well as of multiple genes involved in Ag presentation, reducing the capacity of LC to induce CD4(+) T cells in allogeneic MLR, and thus resulting in a decreased ability of LC to promote CD4(+) T cell proliferation and production of IFN-gamma and IL-10. These data suggest that L3 exert a down-regulatory response in epidermal LC that leads to a diminished capacity of these cells to activate CD4(+) T cells.

  8. Immunization of Mastomys coucha with Brugia malayi recombinant trehalose-6-phosphate phosphatase results in significant protection against homologous challenge infection.

    PubMed

    Kushwaha, Susheela; Singh, Prashant Kumar; Rana, Ajay Kumar; Misra-Bhattacharya, Shailja

    2013-01-01

    Development of a vaccine to prevent or reduce parasite development in lymphatic filariasis would be a complementary approach to existing chemotherapeutic tools. Trehalose-6-phosphate phosphatase of Brugia malayi (Bm-TPP) represents an attractive vaccine target due to its absence in mammals, prevalence in the major life stages of the parasite and immunoreactivity with human bancroftian antibodies, especially from endemic normal subjects. We have recently reported on the cloning, expression, purification and biochemical characterization of this vital enzyme of B. malayi. In the present study, immunoprophylactic evaluation of Bm-TPP was carried out against B. malayi larval challenge in a susceptible host Mastomys coucha and the protective ability of the recombinant protein was evaluated by observing the adverse effects on microfilarial density and adult worm establishment. Immunization caused 78.4% decrease in microfilaremia and 71.04% reduction in the adult worm establishment along with sterilization of 70.06% of the recovered live females. The recombinant protein elicited a mixed Th1/Th2 type of protective immune response as evidenced by the generation of both pro- and anti-inflammatory cytokines IL-2, IFN-γ, TNF-α, IL-4 and an increased production of antibody isotypes IgG1, IgG2a, IgG2b and IgA. Thus immunization with Bm-TPP conferred considerable protection against B. malayi establishment by engendering a long-lasting effective immune response and therefore emerges as a potential vaccine candidate against lymphatic filariasis (LF).

  9. Brugia pahangi in cats: the passive transfer of anti-microfilarial immunity from immune to non-immune cats.

    PubMed

    Medeiros, F; Baldwin, C I; Denham, D A

    1996-02-01

    Serum from cats (Felis catus) that were repeatedly infected with Brugia pahangi and had become amicrofilaraemic (mf-ve) was injected intravenously into microfilaraemic (mf+ve) cats. If more than 1 microliter of immune serum per 1000 mf was injected, microfilarial counts fell dramatically within minutes and, in some cats, mf completely disappeared. In most cases mf reappeared 21-44 days later. However, in two experiments mf never reappeared and circulating antigen (indicative of the presence of living adults) could not be detected. At autopsy no adult worms were found, but in one cat 6 mf/ml were detected by filtration of cardiac blood. Passive transfer of single Ig isotypes showed that IgG is the immunoglobulin responsible for the mf killing effect of immune serum, and that IgG1 is probably the most active isotype. Mf killing and destruction, occurred in the lungs in an antibody dependent cell mediated reaction involving neutrophils, eosinophils and mononuclear cells. Three of the 20 recipient cats died from what appeared to be anaphylactic shock while under anaesthesia probably due to the sudden release of inflammatory mediators in the lung.

  10. The efficacy of a single-oral-dose administration of ivermectin and diethylcarbamazine on the treatment of feline Brugia malayi.

    PubMed

    Chansiri, Gaysorn; Khawsak, Phaisan; Phantana, Sirichai; Sarataphan, Nopporn; Chansiri, Kosum

    2005-09-01

    The combination of ivermectin and diethylcarbamazine (DEC) have been shown to be superior to either drug alone for the suppression of Brugia malayi in humans, but their efficacy against infection with B. malayi in cats has never been investigated. Fourteen asymptomatic microfilaremic (1-200 microfilariae/20 microl blood) cats received oral doses of ivermectin (400 microg/kg body weight) and DEC (6 mg/kg body weight) as a single treatment. A two-month post-treatment examination revealed that 87-100% of the microfilariae in each subject had been cleared, with two of the subjects being amicrofilaremic. A further reduction in microfilarial levels was observed until the final follow-up, at 8 months post-treatment, when the mean clearance rate was 99% and 12 out of the 14 subjects (86%) were amicrofilaremic. The combination of ivermectin and DEC demonstrated a microfilaricidal effect superior to that of either drug used alone, both in the initial rapid clearance of microfilariae, and in sustaining the effect for 8 months. This finding has important implications for the control of brugian lymphatic filariasis in the cat reservoir.

  11. Quantifying the physical and socio-economic burden of filarial lymphoedema in Chikwawa District, Malawi.

    PubMed

    Martindale, Sarah; Mkwanda, Square Z; Smith, Emma; Molyneux, David; Stanton, Michelle C; Kelly-Hope, Louise A

    2014-12-01

    Lymphatic filariasis (LF) is a disfiguring parasitic disease and one of the leading causes of disability in the world. This study aimed to assess the severity of lymphoedema, the physical restrictions and socio-economic impact on affected individuals living in an endemic community in Malawi. In a single health centre catchment area, a follow-up survey was conducted to assess 69 lymphoedema cases, and the impact of their condition in eight different areas of their lives. Differences were examined by sex, age and severity of disease. The overall level of disability was quantified and the impact of acute dermatolymphangioadenitis (ADLA) attacks was examined. Lymphoedema cases were most affected by pain/discomfort and anxiety/depression, which also had an economic impact. Male and older (>60 years) individuals reported more problems. Higher disability levels based on a quantified score were significantly associated with decreased walking distance and working hours. ADLA significantly increased pain/discomfort and reduced cognition, and also affected the individuals' self-care, social participation and ability to work. Filarial lymphoedema causes significant hardship, particularly in relation to ADLAs, and the scale of the problem needs to be better defined with new specific tools so that the best support and care can be provided to those in greatest need. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Oxidative activities in mitochondria-like particles from Setaria digitata, a filarial parasite.

    PubMed Central

    Raj, R K; Puranam, R S; Kurup, C K; Ramasarma, T

    1988-01-01

    The oxidative metabolic potential of Setaria digitata, a filarial parasite found in the intraperitoneal cavity of cattle, was investigated. These worms showed active wriggling movements which were not affected by respiratory poisons such as cyanide, rotenone and malonate. They also possessed cyanide-insensitive and glucose-independent oxygen consumption pathways. By differential centrifugation of sucrose homogenates, a fraction containing mitochondria-like particles was obtained in which the activity of the marker enzyme, succinate dehydrogenase, was recovered. This fraction catalysed succinate- and NADH-dependent reduction of both cytochrome c and dyes. Oxygen uptake found with succinate, NADH and ascorbate as substrates was not sensitive to cyanide. Cytochromes could not be detected in either this fraction or homogenates of the worms. H2O2 generation with a number of substrates and lipid peroxidation by measuring malondialdehyde formed as well as by accompanying oxygen uptake were demonstrated in the mitochondria-like particles. A lipid quinone, possibly with a short side chain and related to ubiquinone, was detected in the worms. The results suggested the existence of two cyanide-insensitive oxygen-consuming reactions in Setaria: one respiratory substrate-independent lipid peroxidation, and a second substrate-dependent reaction that requires an auto-oxidizable quinone but not a cytochrome system. PMID:3223930

  13. Oxidative activities in mitochondria-like particles from Setaria digitata, a filarial parasite.

    PubMed

    Raj, R K; Puranam, R S; Kurup, C K; Ramasarma, T

    1988-12-01

    The oxidative metabolic potential of Setaria digitata, a filarial parasite found in the intraperitoneal cavity of cattle, was investigated. These worms showed active wriggling movements which were not affected by respiratory poisons such as cyanide, rotenone and malonate. They also possessed cyanide-insensitive and glucose-independent oxygen consumption pathways. By differential centrifugation of sucrose homogenates, a fraction containing mitochondria-like particles was obtained in which the activity of the marker enzyme, succinate dehydrogenase, was recovered. This fraction catalysed succinate- and NADH-dependent reduction of both cytochrome c and dyes. Oxygen uptake found with succinate, NADH and ascorbate as substrates was not sensitive to cyanide. Cytochromes could not be detected in either this fraction or homogenates of the worms. H2O2 generation with a number of substrates and lipid peroxidation by measuring malondialdehyde formed as well as by accompanying oxygen uptake were demonstrated in the mitochondria-like particles. A lipid quinone, possibly with a short side chain and related to ubiquinone, was detected in the worms. The results suggested the existence of two cyanide-insensitive oxygen-consuming reactions in Setaria: one respiratory substrate-independent lipid peroxidation, and a second substrate-dependent reaction that requires an auto-oxidizable quinone but not a cytochrome system.

  14. Economic costs of endemic non-filarial elephantiasis in Wolaita Zone, Ethiopia.

    PubMed

    Tekola, Fasil; Mariam, Damen H; Davey, Gail

    2006-07-01

    Endemic non-filarial elephantiasis or podoconiosis is a chronic and debilitating geochemical disease occurring in individuals exposed to red clay soil derived from alkalic volcanic rock. It is a major public health problem in countries in tropical Africa, Central America and North India. To estimate the direct and the average productivity cost attributable to podoconiosis, and to compare the average productivity time of podoconiosis patients with non-patients. Matched comparative cross sectional survey involving 702 study subjects (patients and non-patients) supplemented by interviews with key informants in Wolaita Zone, southern Ethiopia. Total direct costs of podoconiosis amounted to the equivalent of US$ 143 per patient per year. The total productivity loss for a patient amounted to 45% of the total working days per year, causing a monetary loss equivalent to US$ 63. In Wolaita zone, the overall cost of podoconiosis exceeds US$ 16 million per year. Podoconiosis has enormous economic impact in affected areas. Simple preventive measures (such as use of robust footwear) must be promoted by health policy makers.

  15. Removal of regulatory T cell activity reverses hyporesponsiveness and leads to filarial parasite clearance in vivo.

    PubMed

    Taylor, Matthew D; LeGoff, Laetitia; Harris, Anjanette; Malone, Eva; Allen, Judith E; Maizels, Rick M

    2005-04-15

    Human filarial parasites cause chronic infection associated with long-term down-regulation of the host's immune response. We show here that CD4+ T cell regulation is the main determinant of parasite survival. In a laboratory model of infection, using Litomosoides sigmodontis in BALB/c mice, parasites establish for >60 days in the thoracic cavity. During infection, CD4+ T cells at this site express increasing levels of CD25, CTLA-4, and glucocorticoid-induced TNF receptor family-related gene (GITR), and by day 60, up to 70% are CTLA-4(+)GITR(high), with a lesser fraction coexpressing CD25. Upon Ag stimulation, CD4(+)CTLA-4(+)GITR(high) cells are hyporesponsive for proliferation and cytokine production. To test the hypothesis that regulatory T cell activity maintains hyporesponsiveness and prolongs infection, we treated mice with Abs to CD25 and GITR. Combined Ab treatment was able to overcome an established infection, resulting in a 73% reduction in parasite numbers (p < 0.01). Parasite killing was accompanied by increased Ag-specific immune responses and markedly reduced levels of CTLA-4 expression. The action of the CD25(+)GITR+ cells was IL-10 independent as in vivo neutralization of IL-10R did not restore the ability of the immune system to kill parasites. These data suggest that regulatory T cells act, in an IL-10-independent manner, to suppress host immunity to filariasis.

  16. Potential of a soluble tetrazolium/formazan assay for the evaluation of filarial viability.

    PubMed

    Comley, J C; Turner, C H

    1990-04-01

    Using female Acanthocheilonema viteae we have investigated the bioreduction of the tetrazolium reagent XTT (2,3-bis(2-methoxy-4-nitro-sulphonyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide). Unlike the formazan formed by other tetrazolium salts, that derived from XTT readily diffuses out of A. viteae in vitro. Formazan formation can therefore be quantified by direct absorbance reading of the incubation medium, eliminating the need for a DMSO solubilization step. Optimum assay conditions involved a 4 h incubation, in the presence of the electron coupling agent phenazine methosulphate (PMS). Repeat 4 h incubations with XTT-PMS were well tolerated by worms for 5 consecutive days. This confirmed the low toxicity of XTT formazan and its usefulness in the semi-continuous assessment of filarial viability. In comparison to our previously reported MTT (3-(4, 5 dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide)-reduction assay XTT-PMS reduction showed comparable drug sensitivity and accuracy, however XTT-PMS appears to be at least 10-15 times less efficiently reduced by A. viteae females. A possible application of the XTT assay using female Onchocerca volvulus is discussed.

  17. Brugia Rapid™ antibody responses in communities of Indonesia in relation to the results of 'transmission assessment surveys' (TAS) for the lymphatic filariasis elimination program.

    PubMed

    Dewi, Rita M; Tuti, Sekar; Ganefa, Sitti; Anwar, Chairiyah; Larasati, Ria; Ariyanti, Endah; Herjati, Herty; Brady, Molly

    2015-10-01

    The Global Programme to Eliminate Lymphatic Filariasis recommends the transmission assessment survey (TAS) as the preferred methodology for determining whether mass drug administration can be stopped in an endemic area. Because of the limited experience available globally with the use of Brugia Rapid™ tests in conducting TAS in Brugia spp. areas, we explored the relationship between the antibody test results and Brugia spp. infection as detected by microfilaremia in different epidemiological settings. The study analyzes the Brugia Rapid™ antibody responses and microfilaremia in all ages at three study sites in: i) a district which was classified as non-endemic, ii) a district which passed TAS, and iii) a district which failed TAS. Convenience sampling was done in each site, in one to three purposefully selected villages with a goal of 500 samples in each district. A total of 1543 samples were collected from residents in all three study sites. In the site which was classified as non-endemic and where MDA had not been conducted, 5 % of study participants were antibody positive, none was positive for microfilaremia, and age-specific antibody prevalence peaked at almost 8 % in the 25-34 year-old age range, with no antibody-positive results found in children under eight years of age. In the site that had passed TAS, 1 % of participants were antibody positive and none was positive for microfilaremia. In the site which failed TAS, 15 % of participants were antibody positive, 0.2 % were microfilaremic, and age-specific antibody prevalence was highest in 6-7 year olds (30 %), but above 8 % in all age levels above 8 years old. These results from districts which followed the current WHO guidance for mapping, MDA, and implementing TAS, while providing antibody profiles of treated and untreated populations under programmatic settings, support the choice of antibody prevalence in the 6- and 7-year-old age group in TAS for making stopping MDA decisions. Since only one study

  18. Biological Control of Nematodes with Bacteria

    USDA-ARS?s Scientific Manuscript database

    Biological control of nematodes is receiving increased attention as environmental considerations with the use of nematicides have increased in importance and their high cost prohibits use on many crops. In addition, nematode resistant cultivars are not available for many crops and resistance that i...

  19. Endemic Oscheius Nematodes of Hawai'i

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes (EPNs) parasitize insects utilizing mutualistic bacteria to kill the host, allowing the nematode to feed and reproduce within the insect cadaver. Consequently EPNs are highly sought after for their biological control potential. A survey for EPNs was conducted on O’ahu and...

  20. Blends of ascarosides regulate dispersal in nematodes

    USDA-ARS?s Scientific Manuscript database

    Blends of ascarosides regulate dispersal in nematodes Presenter: Dr. Fatma Kaplan Dispersal is an important behavior for many organisms. It can easily be observed when infectious juveniles of entomopathogenic nematodes (Steinernema and Heterorhabditis) leave a consumed insect host. Dauer larvae of ...

  1. Interspecific nematode signals regulate dispersal behavior

    USDA-ARS?s Scientific Manuscript database

    Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2) of plant parasitic Meloidogyne spp. and infective ...

  2. Mechanisms of host seeking by parasitic nematodes.

    PubMed

    Gang, Spencer S; Hallem, Elissa A

    2016-07-01

    The phylum Nematoda comprises a diverse group of roundworms that includes parasites of vertebrates, invertebrates, and plants. Human-parasitic nematodes infect more than one billion people worldwide and cause some of the most common neglected tropical diseases, particularly in low-resource countries [1]. Parasitic nematodes of livestock and crops result in billions of dollars in losses each year [1]. Many nematode infections are treatable with low-cost anthelmintic drugs, but repeated infections are common in endemic areas and drug resistance is a growing concern with increasing therapeutic and agricultural administration [1]. Many parasitic nematodes have an environmental infective larval stage that engages in host seeking, a process whereby the infective larvae use sensory cues to search for hosts. Host seeking is a complex behavior that involves multiple sensory modalities, including olfaction, gustation, thermosensation, and humidity sensation. As the initial step of the parasite-host interaction, host seeking could be a powerful target for preventative intervention. However, host-seeking behavior remains poorly understood. Here we review what is currently known about the host-seeking behaviors of different parasitic nematodes, including insect-parasitic nematodes, mammalian-parasitic nematodes, and plant-parasitic nematodes. We also discuss the neural bases of these behaviors. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Nematodes ultrastructure: complex systems and processes.

    PubMed

    Basyoni, Maha M A; Rizk, Enas M A

    2016-12-01

    Nematode worms are among the most ubiquitous organisms on earth. They include free-living forms as well as parasites of plants, insects, humans and other animals. Recently, there has been an explosion of interest in nematode biology, including the area of nematode ultrastructure. Nematodes are round with a body cavity. They have one way guts with a mouth at one end and an anus at the other. They have a pseudocoelom that is lined on one side with mesoderm and on the other side with endoderm. It appears that the cuticle is a very complex and evolutionarily plastic feature with important functions involving protection, body movement and maintaining shape. They only have longitudinal muscles so; they seem to thrash back and forth. While nematodes have digestive, reproductive, nervous and excretory systems, they do not have discrete circulatory or respiratory systems. Nematodes use chemosensory and mechanosensory neurons embedded in the cuticle to orient and respond to a wide range of environmental stimuli. Adults are made up of roughly 1000 somatic cells and hundreds of those cells are typically associated with the reproductive systems. Nematodes ultrastructure seeks to provide studies which enable their use as models for diverse biological processes including; human diseases, immunity, host-parasitic interactions and the expression of phylogenomics. The latter has, however, not been brought into a single inclusive entity. Consequently, in the current review we tried to provide a comprehensive approach to the current knowledge available for nematodes ultrastructures.

  4. How do humans affect wildlife nematodes?

    USGS Publications Warehouse

    Weinstein, Sara B.; Lafferty, Kevin D.

    2015-01-01

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

  5. Improved nematode extraction from carrot disk culture.

    PubMed

    Kaplan, D T; Davis, E L

    1990-07-01

    Radopholus spp. were reared in carrot tissue culture via established procedures, with slight modification. Several plant tissue maceration enzymes and flotation media (salts and sucrose) were evaluated with regard to nematode toxicity and extraction efficiency. Best extraction of viable nematodes and eggs was attained when carrot tissue infested with Radopholus citrophilus or R. similis was macerated with a mixture of 0.50% driselase and 0.50% cellulysin, w/v each, with 2.5 ml of enzyme solution based for each gram of carrot tissue. Maceration slurries containing carrot tissue and nematodes were maintained in open flasks on a rotary shaker (175 rpm) at 26 C for 24 hours. Nematodes and eggs were extracted from resultant culture slurries by flotation with MgSO-7H0 (sp gr 1.1). A protocol is presented to extract large quantities of viable burrowing nematodes and their eggs from carrot disk cultures.

  6. Improved Nematode Extraction from Carrot Disk Culture

    PubMed Central

    Kaplan, David T.; Davis, Eric L.

    1990-01-01

    Radopholus spp. were reared in carrot tissue culture via established procedures, with slight modification. Several plant tissue maceration enzymes and flotation media (salts and sucrose) were evaluated with regard to nematode toxicity and extraction efficiency. Best extraction of viable nematodes and eggs was attained when carrot tissue infested with Radopholus citrophilus or R. similis was macerated with a mixture of 0.50% driselase and 0.50% cellulysin, w/v each, with 2.5 ml of enzyme solution based for each gram of carrot tissue. Maceration slurries containing carrot tissue and nematodes were maintained in open flasks on a rotary shaker (175 rpm) at 26 C for 24 hours. Nematodes and eggs were extracted from resultant culture slurries by flotation with MgSO₄-7H₂0 (sp gr 1.1). A protocol is presented to extract large quantities of viable burrowing nematodes and their eggs from carrot disk cultures. PMID:19287736

  7. Plant basal resistance to nematodes: an update.

    PubMed

    Holbein, Julia; Grundler, Florian M W; Siddique, Shahid

    2016-03-01

    Most plant-parasitic nematodes are obligate biotrophs feeding on the roots of their hosts. Whereas ectoparasites remain on the root surface and feed on the outer cell layers, endoparasitic nematodes enter the host to parasitize cells around or within the central cylinder. Nematode invasion and feeding causes tissue damage which may, in turn, lead to the activation of host basal defence responses. Hitherto, research interests in plant-nematode interaction have emphasized effector-triggered immunity rather than basal plant defence responses. However, some recent investigations suggest that basal defence pathways are not only activated but also play an important role in determining interaction outcomes. In this review we discuss the major findings and point out future directions to dissect the molecular mechanisms underlying plant basal defence to nematodes further. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. How do humans affect wildlife nematodes?

    PubMed

    Weinstein, Sara B; Lafferty, Kevin D

    2015-05-01

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

  9. Differential Evolutionary Selection and Natural Evolvability Observed in ALT Proteins of Human Filarial Parasites.

    PubMed

    Devoe, Neil C; Corbett, Ian J; Barker, Linsey; Chang, Robert; Gudis, Polyxeni; Mullen, Nathan; Perez, Kailey; Raposo, Hugo; Scholz, John; May, Meghan

    2016-01-01

    The abundant larval transcript (ALT-2) protein is present in all members of the Filarioidea, and has been reported as a potential candidate antigen for a subunit vaccine against lymphatic filariasis. To assess the potential for vaccine escape or heterologous protection, we examined the evolutionary selection acting on ALT-2. The ratios of nonsynonymous (K(a)) to synonymous (K(s)) mutation frequencies (ω) were calculated for the alt-2 genes of the lymphatic filariasis agents Brugia malayi and Wuchereria bancrofti and the agents of river blindness and African eyeworm disease Onchocerca volvulus and Loa loa. Two distinct Bayesian models of sequence evolution showed that ALT-2 of W. bancrofti and L. loa were under significant (P<0.05; P < 0.001) diversifying selection, while ALT-2 of B. malayi and O. volvulus were under neutral to stabilizing selection. Diversifying selection as measured by ω values was notably strongest on the region of ALT-2 encoding the signal peptide of L. loa and was elevated in the variable acidic domain of L. loa and W. bancrofti. Phylogenetic analysis indicated that the ALT-2 consensus sequences formed three clades: the first consisting of B. malayi, the second consisting of W. bancrofti, and the third containing both O. volvulus and L. loa. ALT-2 selection was therefore not predictable by phylogeny or pathology, as the two species parasitizing the eye were selected differently, as were the two species parasitizing the lymphatic system. The most immunogenic regions of L. loa and W. bancrofti ALT-2 sequence as modeled by antigenicity prediction analysis did not correspond with elevated levels of diversifying selection, and were not selected differently than predicted antigenic epitopes in B. malayi and O. volvulus. Measurements of ALT-2 evolvability made by χ2 analysis between alleles that were stable (O. volvulus and B. malayi) and those that were under diversifying selection (W. bancrofti and L. loa) indicated significant (P<0

  10. Differential Evolutionary Selection and Natural Evolvability Observed in ALT Proteins of Human Filarial Parasites

    PubMed Central

    Devoe, Neil C.; Corbett, Ian J.; Barker, Linsey; Chang, Robert; Gudis, Polyxeni; Mullen, Nathan; Perez, Kailey; Raposo, Hugo; Scholz, John; May, Meghan

    2016-01-01

    The abundant larval transcript (ALT-2) protein is present in all members of the Filarioidea, and has been reported as a potential candidate antigen for a subunit vaccine against lymphatic filariasis. To assess the potential for vaccine escape or heterologous protection, we examined the evolutionary selection acting on ALT-2. The ratios of nonsynonymous (K(a)) to synonymous (K(s)) mutation frequencies (ω) were calculated for the alt-2 genes of the lymphatic filariasis agents Brugia malayi and Wuchereria bancrofti and the agents of river blindness and African eyeworm disease Onchocerca volvulus and Loa loa. Two distinct Bayesian models of sequence evolution showed that ALT-2 of W. bancrofti and L. loa were under significant (P<0.05; P < 0.001) diversifying selection, while ALT-2 of B. malayi and O. volvulus were under neutral to stabilizing selection. Diversifying selection as measured by ω values was notably strongest on the region of ALT-2 encoding the signal peptide of L. loa and was elevated in the variable acidic domain of L. loa and W. bancrofti. Phylogenetic analysis indicated that the ALT-2 consensus sequences formed three clades: the first consisting of B. malayi, the second consisting of W. bancrofti, and the third containing both O. volvulus and L. loa. ALT-2 selection was therefore not predictable by phylogeny or pathology, as the two species parasitizing the eye were selected differently, as were the two species parasitizing the lymphatic system. The most immunogenic regions of L. loa and W. bancrofti ALT-2 sequence as modeled by antigenicity prediction analysis did not correspond with elevated levels of diversifying selection, and were not selected differently than predicted antigenic epitopes in B. malayi and O. volvulus. Measurements of ALT-2 evolvability made by χ2 analysis between alleles that were stable (O. volvulus and B. malayi) and those that were under diversifying selection (W. bancrofti and L. loa) indicated significant (P<0

  11. Morphological and molecular characteristics of Malayfilaria sofiani Uni, Mat Udin & Takaoka n. g., n. sp. (Nematoda: Filarioidea) from the common treeshrew Tupaia glis Diard & Duvaucel (Mammalia: Scandentia) in Peninsular Malaysia.

    PubMed

    Uni, Shigehiko; Mat Udin, Ahmad Syihan; Agatsuma, Takeshi; Saijuntha, Weerachai; Junker, Kerstin; Ramli, Rosli; Omar, Hasmahzaiti; Lim, Yvonne Ai-Lian; Sivanandam, Sinnadurai; Lefoulon, Emilie; Martin, Coralie; Belabut, Daicus Martin; Kasim, Saharul; Abdullah Halim, Muhammad Rasul; Zainuri, Nur Afiqah; Bhassu, Subha; Fukuda, Masako; Matsubayashi, Makoto; Harada, Masashi; Low, Van Lun; Chen, Chee Dhang; Suganuma, Narifumi; Hashim, Rosli; Takaoka, Hiroyuki; Azirun, Mohd Sofian

    2017-04-20

    The filarial nematodes Wuchereria bancrofti (Cobbold, 1877), Brugia malayi (Brug, 1927) and B. timori Partono, Purnomo, Dennis, Atmosoedjono, Oemijati & Cross, 1977 cause lymphatic diseases in humans in the tropics, while B. pahangi (Buckley & Edeson, 1956) infects carnivores and causes zoonotic diseases in humans in Malaysia. Wuchereria bancrofti, W. kalimantani Palmieri, Pulnomo, Dennis & Marwoto, 1980 and six out of ten Brugia spp. have been described from Australia, Southeast Asia, Sri Lanka and India. However, the origin and evolution of the species in the Wuchereria-Brugia clade remain unclear. While investigating the diversity of filarial parasites in Malaysia, we discovered an undescribed species in the common treeshrew Tupaia glis Diard & Duvaucel (Mammalia: Scandentia). We examined 81 common treeshrews from 14 areas in nine states and the Federal Territory of Peninsular Malaysia for filarial parasites. Once any filariae that were found had been isolated, we examined their morphological characteristics and determined the partial sequences of their mitochondrial cytochrome c oxidase subunit 1 (cox1) and 12S rRNA genes. Polymerase chain reaction (PCR) products of the internal transcribed spacer 1 (ITS1) region were then cloned into the pGEM-T vector, and the recombinant plasmids were used as templates for sequencing. Malayfilaria sofiani Uni, Mat Udin & Takaoka, n. g., n. sp. is described based on the morphological characteristics of adults and microfilariae found in common treeshrews from Jeram Pasu, Kelantan, Malaysia. The Kimura 2-parameter distance between the cox1 gene sequences of the new species and W. bancrofti was 11.8%. Based on the three gene sequences, the new species forms a monophyletic clade with W. bancrofti and Brugia spp. The adult parasites were found in tissues surrounding the lymph nodes of the neck of common treeshrews. The newly described species appears most closely related to Wuchereria spp. and Brugia spp., but differs from these in

  12. Immunodiagnostic Properties of Wucheraria bancrofti SXP-1, a Potential Filarial Diagnostic Candidate Expressed in Tobacco Plant, Nicotiana tabacum.

    PubMed

    Ganapathy, Mathangi; Chakravarthi, M; Charles, S Jason; Harunipriya, P; Jaiganesh, S; Subramonian, N; Kaliraj, P

    2015-08-01

    Transgenic tobacco plants were developed expressing WbSXP-1, a diagnostic antigen isolated from the cDNA library of L3 stage larvae of Wucheraria bancrofti. This antigen produced by recombinant Escherichia coli has been demonstrated by to be successful as potential diagnostic candidate against lymphatic filariasis. A rapid format simple and qualitative flow through immune-filtration diagnostic kit has been developed for the identification of IgG antibodies to the recombinant WbSXP-1 and is being marketed by M/S Span Diagnostics Ltd in India and Africa. Here, we present the results of experiments on the transformation and expression of the same filarial antigen, WbSXP-1, in tobacco plant, Nicotiana tabacum, to produce plant-based diagnostic antigen. It was possible to successfully transform the tobacco plant with WbSXP-1, the integration of the parasite-specific gene in plants was confirmed by PCR amplification and the expression of the filarial protein by Western blotting. The immunoreactivity of the plant-produced WbSXP-1 was assessed based on its reaction with the monoclonal antibodies developed against the E. coli-produced protein. Immunological screening using clinical sera from patients indicates that the plant-produced protein is comparable to E. coli-produced diagnostic antigen. The result demonstrated that plants can be used as suitable expression systems for the production of diagnostic proteins against lymphatic filariasis, a neglected tropical infectious disease which has a negative impact on socioeconomic development. This is the first report of the integration, expression and efficacy of a diagnostic candidate of lymphatic filariasis in plants.Key MessageTransgenic tobacco plants with WbSXP-1, a filarial diagnostic candidate, were developed. The plant-produced protein showed immunoreactivity on par with the E. coli product.

  13. In silico characterization of a RNA binding protein of cattle filarial parasite Setaria digitata.

    PubMed

    Nagaratnam, Nirupa; Karunanayake, Eric Hamilton; Tennekoon, Kamani Hemamala; Samarakoon, Sameera Ranganath; Mayan, Karthika

    2014-01-01

    Human lymphatic filariasis (HLF) is a neglected tropical disease which threatens nearly 1.4 billion people in 73 countries worldwide. Wuchereria bancrofti is the major causative agent of HLF and it closely resembles cattle filarial parasite Setaria digitata. Due to difficulties in procuring W. bancrofti parasite material, S. digitata cDNA library has been constructed to identify novel drug targets against HLF and many of the cDNA sequences are yet to be assigned structure and function. In this study, a 549 bp long cDNA (sdrbp) has been sequenced and characterized in silico. The shortest ORF of 249 bp from the isolated cDNA encodes a polypeptide of 82 amino acids and shows an amino acid identity of 54% with the RRM domain of human cleavage stimulation factor-64 kDa subunit (CstF-64). Structure of the protein (sdRBP) obtained by homology modelling using RRM of CstF-64 as template adopts classical RRM topology (β1α1β2β3α2β4). sdRBP model built was validated by superimposition tools and Ramachandran plot analysis. CstF-64 plays an important role in pre-mRNA polyadenylation by interacting with specific GU-rich downstream sequence element. Molecular docking studies of sdRBP with different RNA molecules revealed that sdRBP has greater binding affinity to GU-rich RNA and comparable results were obtained upon similar docking of RRM of CstF-64 with the same RNA molecules. Therefore, sdRBP is likely to perform homologous function in S. digitata. This study brings new dimensions to the functional analysis of RNA binding proteins of S. digitata and their evaluation as new drug targets against HLF.

  14. In silico characterization of a RNA binding protein of cattle filarial parasite Setaria digitata

    PubMed Central

    Nagaratnam, Nirupa; Karunanayake, Eric Hamilton; Tennekoon, Kamani Hemamala; Samarakoon, Sameera Ranganath; Mayan, Karthika

    2014-01-01

    Human lymphatic filariasis (HLF) is a neglected tropical disease which threatens nearly 1.4 billion people in 73 countries worldwide. Wuchereria bancrofti is the major causative agent of HLF and it closely resembles cattle filarial parasite Setaria digitata. Due to difficulties in procuring W. bancrofti parasite material, S. digitata cDNA library has been constructed to identify novel drug targets against HLF and many of the cDNA sequences are yet to be assigned structure and function. In this study, a 549 bp long cDNA (sdrbp) has been sequenced and characterized in silico. The shortest ORF of 249 bp from the isolated cDNA encodes a polypeptide of 82 amino acids and shows an amino acid identity of 54% with the RRM domain of human cleavage stimulation factor-64 kDa subunit (CstF-64). Structure of the protein (sdRBP) obtained by homology modelling using RRM of CstF-64 as template adopts classical RRM topology (β1α1β2β3α2β4). sdRBP model built was validated by superimposition tools and Ramachandran plot analysis. CstF-64 plays an important role in pre-mRNA polyadenylation by interacting with specific GU-rich downstream sequence element. Molecular docking studies of sdRBP with different RNA molecules revealed that sdRBP has greater binding affinity to GU-rich RNA and comparable results were obtained upon similar docking of RRM of CstF-64 with the same RNA molecules. Therefore, sdRBP is likely to perform homologous function in S. digitata. This study brings new dimensions to the functional analysis of RNA binding proteins of S. digitata and their evaluation as new drug targets against HLF. PMID:25258487

  15. Point-of-care quantification of blood-borne filarial parasites with a mobile phone microscope.

    PubMed

    D'Ambrosio, Michael V; Bakalar, Matthew; Bennuru, Sasisekhar; Reber, Clay; Skandarajah, Arunan; Nilsson, Lina; Switz, Neil; Kamgno, Joseph; Pion, Sébastien; Boussinesq, Michel; Nutman, Thomas B; Fletcher, Daniel A

    2015-05-06

    Parasitic helminths cause debilitating diseases that affect millions of people in primarily low-resource settings. Efforts to eliminate onchocerciasis and lymphatic filariasis in Central Africa through mass drug administration have been suspended because of ivermectin-associated serious adverse events, including death, in patients infected with the filarial parasite Loa loa. To safely administer ivermectin for onchocerciasis or lymphatic filariasis in regions co-endemic with L. loa, a strategy termed "test and (not) treat" has been proposed whereby those with high levels of L. loa microfilariae (>30,000/ml) that put them at risk for life-threatening serious adverse events are identified and excluded from mass drug administration. To enable this, we developed a mobile phone-based video microscope that automatically quantifies L. loa microfilariae in whole blood loaded directly into a small glass capillary from a fingerprick without the need for conventional sample preparation or staining. This point-of-care device automatically captures and analyzes videos of microfilarial motion in whole blood using motorized sample scanning and onboard motion detection, minimizing input from health care workers and providing a quantification of microfilariae per milliliter of whole blood in under 2 min. To validate performance and usability of the mobile phone microscope, we tested 33 potentially Loa-infected patients in Cameroon and confirmed that automated counts correlated with manual thick smear counts (94% specificity; 100% sensitivity). Use of this technology to exclude patients from ivermectin-based treatment at the point of care in Loa-endemic regions would allow resumption/expansion of mass drug administration programs for onchocerciasis and lymphatic filariasis in Central Africa. Copyright © 2015, American Association for the Advancement of Science.

  16. Thioredoxin peroxidase from Onchocerca volvulus: a major hydrogen peroxide detoxifying enzyme in filarial parasites.

    PubMed

    Lu, W; Egerton, G L; Bianco, A E; Williams, S A

    1998-03-15

    Random screening of an Onchocerca volvulus third-stage (L3) cDNA library identified a highly abundant cDNA encoding a newly discovered antioxidant enzyme, thioredoxin peroxidase (TPx), a member of the peroxidoxin superfamily. This TPx cDNA (Ov-tpx-2) encodes a polypeptide of 199 amino acid residues with a calculated molecular weight of 21,890 Da. The Ov-tpx-2 cDNA represents roughly 2.5% of the total cDNAs from the L3 cDNA library. The gene was expressed in Escherichia coli and the protein product was shown to have antioxidant activity. Antiserum raised against Ov-TPX-2 recognized a native protein from extracts of both the L3 and adult-stages with a molecular weight of 22 kD. The localization and stage-specificity of Ov-TPX-2 protein was analyzed by immunocytochemistry and immunoelectron microscopy using monospecific antibodies. Expression was detected in late first-stage larvae during development in the vector and increased in intensity during differentiation to the infective L3-stage. The antigen was also detected in post-infective larvae and adult worms. In larvae, Ov-TPX-2 protein was predominantly localized to the hypodermis and cuticle, with additional sites in the hypodermal chords and multivesicular bodies. In adult worms, the primary sites of expression were the uterine epithelium and intestine, with additional labeling of the body wall and cuticle. Developing embryos and microfilariae in utero were bathed in Ov-TPX-2 protein discharged from epithelial cells. These results suggest that Ov-TPX-2 may protect the parasites from being damaged by host-generated oxidative stress and that Ov-TPX-2 protein provides the H2O2-detoxifying activity predicted but not previously identified in filarial parasites. Its highly upregulated expression in infective larvae may aid in parasite establishment following transmission to the definitive host.

  17. Multiple filarial species microfilaraemia: a comparative study of areas with endemic and sporadic onchocerciasis.

    PubMed

    Uttah, Emmanuel; Ibeh, Dominic C

    2011-12-01

    The study was aimed at determining the pattern of co-occurrence of species of microfilaraemia between onchocerciasis endemic and sporadic populations. From every consenting person of one year and above, 50 μl of day and night blood samples were collected and processed respectively with Haemotoxylin and Giemsa as vital stains. Two skin snips (one each from the waist and the shoulder) were also taken from these individuals and processed. Results showed single species microfilaraemia (86.4 and 82.3%), double species microfilaraemia (12.2 and 16.9%) and triple species microfilaraemia (1.4 and 0.7%) for endemic and sporadic populations respectively. All the species had single species microfilaraemia mostly, but Mansonella perstans and Loa loa showed greatest tendency towards double and triple species microfilaraemia. The prevalence of Wuchereria bancrofti microfilaraemia among those positive for Onchocerca volvulus was significantly lower than the overall prevalence of Wuchereria bancrofti. Wuchereria bancrofti microfilaraemia was most common among those who had L. loa microfilaraemia. Wuchereria bancrofti microfilarial intensity was higher among those with M. perstans microfilaraemia than among those positive for any of the other filarial species. Similarly, the intensity of M. perstans microfilaraemia among those positive for W. bancrofti exceeded the overall intensity of M. perstans. It is concluded that there was no definite pattern in mf densities discernible from co- occurrence infections either in the onchocerciasis endemic or sporadic population. There could be varied outcomes of onchocerciasis infection attributable to positive or negative regulatory effects of other pathogens harbored by the victims.

  18. The further application of MTT-formazan colorimetry to studies on filarial worm viability.

    PubMed

    Comley, J C; Townson, S; Rees, M J; Dobinson, A

    1989-09-01

    Experiments have confirmed that MTT-formazan colorimetry in its simplest form (incubation of intact worms with MTT and direct visualisation of any formazan formed) can be readily applied to several species of filariae including Onchocerca volvulus. Data is presented which will assist the development of quantitative MTT reduction viability tests for a selection of the smaller filarial species. Assays of pieces of Onchocerca gutturosa and O. volvulus females have led us to tentatively conclude that the tips of filariae, particularly the anterior ends, may well be metabolically the most active part of the worm. Selective sampling of these regions for Onchocerca might therefore be a useful indicator for the viability of the parasite. An example of how MTT-formazan colorimetry has been applied to yield additional data to support motility observations on the in vitro survival of male O. gutturosa is also given. The in vitro timecourse of worm death caused by 10 microM CGP 20376 on Acanthocheilonema viteae females has been examined by MTT reduction and compared with 6 other non-subjective parameters. The results suggests that the parameters examined could be divided into two groups according to the time taken for CGP 20376 to cause 50% inhibition (t50) of the parameter. Fast response parameters had t50's between 1 and 6 h (motility indices, 14CO2 evolution, adenine uptake and leucine uptake), they are more sensitive measures of viability and indicate possible worm damage which may or may not be reversible. Slow response parameters had t50's between 34 and 48.5 h (lactate output, MTT reduction and adenine leakage), and are probably linked with severe degenerative changes and are indicative of worm death.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Silver nanoparticles: a possibility for malarial and filarial vector control technology.

    PubMed

    Soni, Namita; Prakash, Soam

    2014-11-01

    Green synthesis technology is one of the rapid, reliable and best routes for the synthesis of silver nanoparticles (AgNPs). There are bioactive compounds with enormous potential in Azadirachta indica (Neem). The extraordinary mosquitoes warrant nanotechnology to integrate with novel molecules. This will be sustainable technology for future. Here, we synthesized AgNPs using aqueous extracts of leaves and bark of Az. indica (Neem). We tested AgNPs as larvicides, pupicides and adulticides against the malaria vector Anopheles stephensi and filariasis vector Culex quinquefasciatus. The results were obtained using UV-visible spectrophotometer and the images were recorded with a transmission electron microscope (TEM). The efficacy tests were then performed at different concentrations varying many hours by probit analysis. The synthesized AgNPs were spherical in shape and with varied sizes (10.47-nm leaf and 19.22-nm bark). The larvae, pupae and adults of filariasis vector C. quinquefasciatus were found to be more susceptible to our AgNPs than the malaria vector An. stephensi. The first and the second instar larvae of C. quinquefasciatus show a mortality rate of 100% after 30 min of exposure. The results against the pupa of C. quinquefasciatus were recorded as LC₅₀ 4 ppm, LC₉₀ 11 ppm and LC₉₉ 13 ppm after 3 h of exposure. In the case of adult mosquitoes, LC₅₀ 1.06 μL/cm(2), LC₉₀ 2.13 μL/cm(2) and LC₉₉ 2.4 μL/cm(2) were obtained after 4 h of exposure. These results suggest that our AgNPs are environment-friendly for controlling malarial and filarial vectors.

  20. Nondestructive imaging of plant-parasitic nematode development and host response to nematode pathogenesis.

    PubMed

    Dinh, Phuong T Y; Knoblauch, Michael; Elling, Axel A

    2014-05-01

    The secluded lifestyle of endoparasitic plant nematodes hampers progress toward a comprehensive understanding of plant-nematode interactions. A novel technique that enables nondestructive, long-term observations of a wide range of live nematodes in planta is presented here. As proof of principle, Pratylenchus penetrans, Heterodera schachtii, and Meloidogyne chitwoodi were labeled fluorescently with PKH26 and used to infect Arabidopsis thaliana grown in microscopy rhizosphere chambers. Nematode behavior, development, and morphology were observed for the full duration of each parasite's life cycle by confocal microscopy for up to 27 days after inoculation. PKH26 accumulated in intestinal lipid droplets and had no negative effect on nematode infectivity. This technique enabled visualization of Meloidogyne gall formation, nematode oogenesis, and nematode morphological features, such as the metacorpus, vulva, spicules, and cuticle. Additionally, microscopy rhizosphere chambers were used to characterize plant organelle dynamics during M. chitwoodi infection. Peroxisome abundance strongly increased in early giant cells but showed a marked decrease at later stages of feeding site development, which suggests a modulation of plant peroxisomes by root-knot nematodes during the infection process. Taken together, this technique facilitates studies aimed at deciphering plant-nematode interactions at the cellular and subcellular level and enables unprecedented insights into nematode behavior in planta.

  1. Immunization of Mastomys coucha with Brugia malayi Recombinant Trehalose-6-Phosphate Phosphatase Results in Significant Protection against Homologous Challenge Infection

    PubMed Central

    Kushwaha, Susheela; Singh, Prashant Kumar; Rana, Ajay Kumar; Misra-Bhattacharya, Shailja

    2013-01-01

    Development of a vaccine to prevent or reduce parasite development in lymphatic filariasis would be a complementary approach to existing chemotherapeutic tools. Trehalose-6-phosphate phosphatase of Brugia malayi (Bm-TPP) represents an attractive vaccine target due to its absence in mammals, prevalence in the major life stages of the parasite and immunoreactivity with human bancroftian antibodies, especially from endemic normal subjects. We have recently reported on the cloning, expression, purification and biochemical characterization of this vital enzyme of B. malayi. In the present study, immunoprophylactic evaluation of Bm-TPP was carried out against B. malayi larval challenge in a susceptible host Mastomys coucha and the protective ability of the recombinant protein was evaluated by observing the adverse effects on microfilarial density and adult worm establishment. Immunization caused 78.4% decrease in microfilaremia and 71.04% reduction in the adult worm establishment along with sterilization of 70.06% of the recovered live females. The recombinant protein elicited a mixed Th1/Th2 type of protective immune response as evidenced by the generation of both pro- and anti-inflammatory cytokines IL-2, IFN-γ, TNF-α, IL-4 and an increased production of antibody isotypes IgG1, IgG2a, IgG2b and IgA. Thus immunization with Bm-TPP conferred considerable protection against B. malayi establishment by engendering a long-lasting effective immune response and therefore emerges as a potential vaccine candidate against lymphatic filariasis (LF). PMID:24015262

  2. Current research on the major nematode problems in Japan.

    PubMed

    Ichinohe, M

    1988-04-01

    AMONG IMPORTANT NEMATODE SPECIES OCCURRING IN JAPAN, CURRENT RESEARCH ACHIEVEMENTS WITH THE FOLLOWING FOUR NEMATODES ARE REVIEWED: 1) Soybean cyst nematode (SCN), Heterodera glycines - breeding for resistance, race determination, association with Cephalosporium gregatum in azuki bean disease, and isolation of hatching stimulant. 2) Potato-cyst nematode (PCN), Globodera rostochiensis - pathotype determination (Ro 1), breeding for resistance, and control recommendations. 3) Pinewood nematode (PWN), Bursaphelenchus xylophilus - primary pathogen in pine wilt disease, life cycle exhibiting a typical symbiosis with Japanese pine sawyer, Monochamus alternatus, and project for control. 4) Rice root nematodes (RRN), Hirschmanniella imamuri and H. oryzae - distribution of species, population levels in roots, and role of these nematodes in rice culture.

  3. Parasitic nematodes - from genomes to control.

    PubMed

    Mitreva, Makedonka; Zarlenga, Dante S; McCarter, James P; Jasmer, Douglas P

    2007-08-19

    The diseases caused by parasitic nematodes in domestic and companion animals are major factors that decrease production and quality of the agricultural products. Methods available for the control of the parasitic nematode infections are mainly based on chemical treatment, non-chemical management practices, immune modulation and biological control. However, even with integrated pest management that frequently combines these approaches, the effective and long-lasting control strategies are hampered by the persistent exposure of host animals to environmental stages of parasites, the incomplete protective response of the host and acquisition of anthelmintic resistance by an increasing number of parasitic nematodes. Therefore, the challenges to improve control of parasitic nematode infections are multi-fold and no single category of information will meet them all. However, new information, such as nematode genomics, functional genomics and proteomics, can strengthen basic and applied biological research aimed to develop improvements. In this review we will, summarize existing control strategies of nematode infections and discuss ongoing developments in nematode genomics. Genomics approaches offer a growing and fundamental base of information, which when coupled with downstream functional genomics and proteomics can accelerate progress towards developing more efficient and sustainable control programs.

  4. A Cell-Based Screen Reveals that the Albendazole Metabolite, Albendazole Sulfone, Targets Wolbachia

    PubMed Central

    Bray, Walter M.; White, Pamela M.; Ruybal, Jordan; Lokey, R. Scott; Debec, Alain; Sullivan, William

    2012-01-01

    Wolbachia endosymbionts carried by filarial nematodes give rise to the neglected diseases African river blindness and lymphatic filariasis afflicting millions worldwide. Here we identify new Wolbachia-disrupting compounds by conducting high-throughput cell-based chemical screens using a Wolbachia-infected, fluorescently labeled Drosophila cell line. This screen yielded several Wolbachia-disrupting compounds including three that resembled Albendazole, a widely used anthelmintic drug that targets nematode microtubules. Follow-up studies demonstrate that a common Albendazole metabolite, Albendazole sulfone, reduces intracellular Wolbachia titer both in Drosophila melanogaster and Brugia malayi, the nematode responsible for lymphatic filariasis. Significantly, Albendazole sulfone does not disrupt Drosophila microtubule organization, suggesting that this compound reduces titer through direct targeting of Wolbachia. Accordingly, both DNA staining and FtsZ immunofluorescence demonstrates that Albendazole sulfone treatment induces Wolbachia elongation, a phenotype indicative of binary fission defects. This suggests that the efficacy of Albendazole in treating filarial nematode-based diseases is attributable to dual targeting of nematode microtubules and their Wolbachia endosymbionts. PMID:23028321

  5. A cell-based screen reveals that the albendazole metabolite, albendazole sulfone, targets Wolbachia.

    PubMed

    Serbus, Laura R; Landmann, Frederic; Bray, Walter M; White, Pamela M; Ruybal, Jordan; Lokey, R Scott; Debec, Alain; Sullivan, William

    2012-09-01

    Wolbachia endosymbionts carried by filarial nematodes give rise to the neglected diseases African river blindness and lymphatic filariasis afflicting millions worldwide. Here we identify new Wolbachia-disrupting compounds by conducting high-throughput cell-based chemical screens using a Wolbachia-infected, fluorescently labeled Drosophila cell line. This screen yielded several Wolbachia-disrupting compounds including three that resembled Albendazole, a widely used anthelmintic drug that targets nematode microtubules. Follow-up studies demonstrate that a common Albendazole metabolite, Albendazole sulfone, reduces intracellular Wolbachia titer both in Drosophila melanogaster and Brugia malayi, the nematode responsible for lymphatic filariasis. Significantly, Albendazole sulfone does not disrupt Drosophila microtubule organization, suggesting that this compound reduces titer through direct targeting of Wolbachia. Accordingly, both DNA staining and FtsZ immunofluorescence demonstrates that Albendazole sulfone treatment induces Wolbachia elongation, a phenotype indicative of binary fission defects. This suggests that the efficacy of Albendazole in treating filarial nematode-based diseases is attributable to dual targeting of nematode microtubules and their Wolbachia endosymbionts.

  6. Ascaroside Signaling is Widely Conserved Among Nematodes

    PubMed Central

    Choe, Andrea; von Reuss, Stephan H.; Kogan, Dima; Gasser, Robin B.; Platzer, Edward G.; Schroeder, Frank C.; Sternberg, Paul W.

    2012-01-01

    Summary Background Nematodes are among the most successful animals on earth and include important human pathogens, yet little is known about nematode pheromone systems. A group of small molecules called ascarosides has been found to mediate mate finding, aggregation, and developmental diapause in Caenorhabditis elegans, but it is unknown whether ascaroside signaling exists outside of the genus Caenorhabditis. Results To determine whether ascarosides are used as signaling molecules by other nematode species, we performed a mass spectrometry-based screen for ascarosides in secretions from a variety of both free-living and parasitic (plant, insect, and animal) nematodes. We found that most of the species analyzed, including nematodes from several different clades, produce species-specific ascaroside mixtures. In some cases, ascaroside biosynthesis patterns appear to correlate with phylogeny, whereas in other cases, biosynthesis seems to correlate with lifestyle and ecological niche. We further show that ascarosides mediate distinct nematode behaviors, such as retention, avoidance, and long-range attraction, and that different nematode species respond to distinct, but overlapping, sets of ascarosides. Conclusions Our findings indicate that nematodes utilize a conserved family of signaling molecules despite having evolved to occupy diverse ecologies. Their structural features and level of conservation are evocative of bacterial quorum sensing, where acyl homoserine lactones (AHLs) are both produced and sensed by many species of Gram-negative bacteria. The identification of species-specific ascaroside profiles may enable pheromone-based approaches to interfere with reproduction and survival of parasitic nematodes, which are responsible for significant agricultural losses and many human diseases worldwide. PMID:22503501

  7. [Nematodes of humans in the Primorye Territory].

    PubMed

    Ermolenko, A V; Rumiantseva, E E; Bartkova, A D; Voronok, V M; Poliakova, L F

    2013-01-01

    Nematodes occupy the top in the general pattern of human parasitic diseases in the Primorye Territory. In the south of the Far East, there are a total of 28 nematode species that can parasitize man. However, the authors have identified only 8 nematode-induced diseases, such as ascariasis, enterobiasis, toxocariasis, trichocephaliasis, anisakiasis, trichinosis, dirofilariasis, dioctophymosis. The latter has been found only once in the 1920s. According to official statistical data, the proportion of ascariasis and enterobiasis accounted for 43.8 and 53.5% of the total number of helminthiases, respectively.

  8. The FLP-side of nematodes.

    PubMed

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

    2006-08-01

    The central role of FMRFamide-like peptides (FLPs) in nematode motor and sensory capabilities makes FLP signalling an appealing target for new parasiticides. Accumulating evidence has revealed an astounding level of FLP sequence conservation and diversity in the phylum Nematoda, and preliminary work has begun to identify the nematode FLP receptor complement in Caenorhabditis elegans, with a view to investigating their basic biology and therapeutic potential. However, much work is needed to clarify the functional aspects of FLP signalling and how these peptides exert their effects at the organismal level. Here, we summarize our current knowledge of nematode FLP signalling.

  9. Physical, psychological, and social aspects of quality of life in filarial lymphedema patients in Colombo, Sri Lanka.

    PubMed

    Wijesinghe, Rushika S; Wickremasinghe, Ananda R

    2015-03-01

    Quality of life (QOL) was assessed in 141 filarial lymphedema patients and 128 healthy people in the Colombo district, Sri Lanka, by administering modified, translated, and validated (in Sri Lanka) versions of the Short Form 36 health survey questionnaire (SF-36) and the 30-item General Health questionnaire (GHQ-30). The GHQ-30 assesses the current mental health status. The SF-36 measures health on 8 multi-item dimensions covering functional state, well-being, and overall evaluation of health (physical functioning, role limitations resulting from physical health problems, role limitations resulting from emotional problems, energy/fatigue, emotional well-being, social functioning, pain and general health). By SF-36, patients experienced poorer physical functioning, more role limitations resulting from physical health conditions, less emotional well-being, poorer social functioning, and more pain than healthy individuals. By GHQ-30, mental well-being of healthy controls was significantly better than that of patients. The significant difference in the QOL as perceived by filarial lymphedema patients and healthy individuals reiterates the importance of morbidity control in patients affected by this disease.

  10. Immunohistological studies on neoplasms of female and male Onchocerca volvulus: filarial origin and absence of Wolbachia from tumor cells.

    PubMed

    Brattig, N W; Hoerauf, A; Fischer, P U; Liebau, E; Bandi, C; Debrah, A; Büttner, M; Büttner, D W

    2010-04-01

    Up to 5% of untreated female Onchocerca volvulus filariae develop potentially fatal pleomorphic neoplasms, whose incidence is increased following ivermectin treatment. We studied the occurrence of 8 filarial proteins and of Wolbachia endobacteria in the tumor cells. Onchocercomas from patients, untreated and treated with antibiotics and anthelminthics, were examined by immunohistology. Neoplasms were diagnosed in 112 of 3587 female and in 2 of 1570 male O. volvulus. The following proteins and other compounds of O. volvulus were expressed in the cells of the neoplasms: glutathione S-transferase 1, lysosomal aspartic protease, cAMP-dependent protein kinase, alpha-enolase, aspartate aminotransferase, ankyrin E1, tropomyosin, heat shock protein 60, transforming growth factor-beta, and prostaglandin E(2). These findings prove the filarial origin of the neoplasms and confirm the pleomorphism of the tumor cells. Signs indicating malignancy of the neoplasms are described. Wolbachia were observed in the hypodermis, oocytes, and embryos of tumor-harbouring filariae using antibodies against Wolbachia surface protein, Wolbachia HtrA-type serine protease, and Wolbachia aspartate aminotransferase. In contrast, Wolbachia were not found in the cells of the neoplasms. Further, neoplasm-containing worms were not observed after more than 10 months after the start of sufficient treatment with doxycycline or doxycycline plus ivermectin.

  11. Immunohistological studies on neoplasms of female and male Onchocerca volvulus: filarial origin and absence of Wolbachia from tumor cells

    PubMed Central

    BRATTIG, N. W.; HOERAUF, A.; FISCHER, P. U.; LIEBAU, E.; BANDI, C.; DEBRAH, A.; BÜTTNER, M.; BÜTTNER, D. W.

    2010-01-01

    SUMMARY Up to 5% of untreated female Onchocerca volvulus filariae develop potentially fatal pleomorphic neoplasms, whose incidence is increased following ivermectin treatment. We studied the occurrence of 8 filarial proteins and of Wolbachia endobacteria in the tumor cells. Onchocercomas from patients, untreated and treated with antibiotics and anthelminthics, were examined by immunohistology. Neoplasms were diagnosed in 112 of 3587 female and in 2 of 1570 male O. volvulus. The following proteins and other compounds of O. volvulus were expressed in the cells of the neoplasms: glutathione S-transferase 1, lysosomal aspartic protease, cAMP-dependent protein kinase, alpha-enolase, aspartate aminotransferase, ankyrin E1, tropomyosin, heat shock protein 60, transforming growth factor-beta, and prostaglandin E2. These findings prove the filarial origin of the neoplasms and confirm the pleomorphism of the tumor cells. Signs indicating malignancy of the neoplasms are described. Wolbachia were observed in the hypodermis, oocytes, and embryos of tumor-harbouring filariae using antibodies against Wolbachia surface protein, Wolbachia HtrA-type serine protease, and Wolbachia aspartate aminotransferase. In contrast, Wolbachia were not found in the cells of the neoplasms. Further, neoplasm-containing worms were not observed after more than 10 months after the start of sufficient treatment with doxycycline or doxycycline plus ivermectin. PMID:20199697

  12. Filarial Antigenemia and Loa loa Night Blood Microfilaremia in an Area Without Bancroftian Filariasis in the Democratic Republic of Congo

    PubMed Central

    Bakajika, Didier K.; Nigo, Maurice M.; Lotsima, Jean Pierre; Masikini, Germain A.; Fischer, Kerstin; Lloyd, Melanie M.; Weil, Gary J.; Fischer, Peter U.

    2014-01-01

    Implementation of mass drug administration for lymphatic filariasis (LF) has been delayed in central Africa because of incomplete mapping and coendemic loiasis. We mapped two regions in eastern Democratic Republic of Congo that were suspected to have LF. Night blood samples were collected from 2,724 subjects in 30 villages. Filarial antigenemia rates by card test exceeded 1% in 28 villages (range = 0–14%). Prevalence rates for large sheathed microfilariae (Mf) ranged from 4% to 40%; Mansonella perstans rates ranged from 22% to 98%. Large Mf were exclusively Loa loa by microscopy, and only 1 of 337 samples tested by quantitative polymerase chain reaction (qPCR) was positive for Wuchereria bancrofti DNA. Filarial antigen positivity was strongly associated with high L. loa Mf counts. Periodicity studies revealed atypical patterns, with no significant diurnal periodicity in some individuals. Thus, methods routinely used for LF mapping may not be reliable in areas in central Africa that are highly endemic for loiasis. PMID:25223938

  13. Filarial antigenemia and Loa loa night blood microfilaremia in an area without bancroftian filariasis in the Democratic Republic of Congo.

    PubMed

    Bakajika, Didier K; Nigo, Maurice M; Lotsima, Jean Pierre; Masikini, Germain A; Fischer, Kerstin; Lloyd, Melanie M; Weil, Gary J; Fischer, Peter U

    2014-12-01

    Implementation of mass drug administration for lymphatic filariasis (LF) has been delayed in central Africa because of incomplete mapping and coendemic loiasis. We mapped two regions in eastern Democratic Republic of Congo that were suspected to have LF. Night blood samples were collected from 2,724 subjects in 30 villages. Filarial antigenemia rates by card test exceeded 1% in 28 villages (range = 0-14%). Prevalence rates for large sheathed microfilariae (Mf) ranged from 4% to 40%; Mansonella perstans rates ranged from 22% to 98%. Large Mf were exclusively Loa loa by microscopy, and only 1 of 337 samples tested by quantitative polymerase chain reaction (qPCR) was positive for Wuchereria bancrofti DNA. Filarial antigen positivity was strongly associated with high L. loa Mf counts. Periodicity studies revealed atypical patterns, with no significant diurnal periodicity in some individuals. Thus, methods routinely used for LF mapping may not be reliable in areas in central Africa that are highly endemic for loiasis. © The American Society of Tropical Medicine and Hygiene.

  14. Development and testing of a de novo clinical staging system for podoconiosis (endemic non-filarial elephantiasis)

    PubMed Central

    Tekola, Fasil; Ayele, Zewdu; HaileMariam, Dereje; Fuller, Claire; Davey, Gail

    2010-01-01

    Summary Background Podoconiosis (endemic non-filarial elephantiasis) is a geochemical disease in individuals exposed to red-clay soil. Despite the prevalence and public health importance of podoconiosis, there is as yet no accepted clinical staging system. Objective We aimed to develop and test a robust clinical staging system for podoconiosis. Methods We adapted the Dreyer system for staging filarial lymphoedema and tested it in four re-iterative field tests conducted in an area of high podoconiosis prevalence in Southern Ethiopia. The system finally arrived at has five stages according to proximal spread of disease and presence of dermal nodules, ridges and bands. We measured the one-week repeatability and the inter-observer agreement of the final staging system. Results We have developed a five-stage system that is readily understood by community workers with little health training. Kappa for one-week repeatability was 0.88 (95% CI 0.80 to 0.96), Kappa for agreement between health professionals was 0.71 (95% CI 0.60 to 0.82), while that between health professionals and community podoconiosis agents without formal health training averaged 0.64 (95% CI 0.52 to 0.78). Conclusions A simple staging system with good inter-observer agreement and repeatability has been developed to assist in the management and further study of podoconiosis. PMID:18721188

  15. Persistence of lymphatic filarial infection in the paediatric population of rural community, after six rounds of annual mass drug administrations.

    PubMed

    Sunish, I P; Munirathinam, A; Kalimuthu, M; Ashok Kumar, V; Tyagi, B K

    2014-06-01

    Under the Global Programme to Eliminate Lymphatic Filariasis (LF), mass drug administration (MDA) is being implemented in Tamil Nadu, south India, by the State health machinery. The impact of six annual rounds of MDA using diethylcarbamazine (DEC) with and without albendazole (ALB) on filarial infection (microfilaraemia prevalence-MFP; antigenaemia prevalence-AGP) in paediatric population of 2-9 years was determined in two revenue blocks, with a population of 321 000. After each MDA, 300-400 children were screened for filarial infection. After six MDAs, an overall MFP reduction of 84.67% and 57.95% was observed in DEC+ALB and DEC alone arms, respectively. Corresponding AGP reductions were 72.88% (p < 0.001) and 41.51% (p = 0.023). Observation of microfilaraemic children after six MDAs (0.32% in DEC+ALB; 0.75% in DEC alone), necessitates the need for supplementary control strategies (viz., vector control), in order to achieve the goal of LF elimination. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Nematode endogenous small RNA pathways

    PubMed Central

    Hoogstrate, Suzanne W; Volkers, Rita JM; Sterken, Mark G; Kammenga, Jan E; Snoek, L Basten

    2014-01-01

    The discovery of small RNA silencing pathways has greatly extended our knowledge of gene regulation. Small RNAs have been presumed to play a role in every field of biology because they affect many biological processes via regulation of gene expression and chromatin remodeling. Most well-known examples of affected processes are development, fertility, and maintenance of genome stability. Here we review the role of the three main endogenous small RNA silencing pathways in Caenorhabditis elegans: microRNAs, endogenous small interfering RNAs, and PIWI-interacting RNAs. After providing an entry-level overview on how these pathways function, we discuss research on other nematode species providing insight into the evolution of these small RNA pathways. In understanding the differences between the endogenous small RNA pathways and their evolution, a more comprehensive picture is formed of the functions and effects of small RNAs. PMID:25340013

  17. Fitness cost of Litomosoides sigmodontis filarial infection in mite vectors; implications of infected haematophagous arthropod excretory products in host-vector interactions.

    PubMed

    Nieguitsila, Adélaïde; Frutos, Roger; Moulia, Catherine; Lhermitte-Vallarino, Nathaly; Bain, Odile; Gavotte, Laurent; Martin, Coralie

    2013-01-01

    Filariae are a leading cause of infections which are responsible for serious dermatological, ocular, and vascular lesions. Infective third stage larvae (L3) are transmitted through the bite of a haematophagous vector. Litomosoides sigmodontis is a well-established model of filariasis in the mouse, with the vector being the mite Ornithonyssus bacoti. The aim of the study was to analyse the filarial infection in mites to determine the consequences of filarial infection in the blood-feeding and the reproduction of mites as well as in the regulation of vector-induced inflammation in the mouse skin. Firstly, L3 are unevenly distributed throughout the host population and the majority of the population harbours a moderate infection (1 to 6 L3). Filarial infection does not significantly affect the probing delay for blood feeding. The number of released protonymphs is lower in infected mites but is not correlated with the L3 burden. Finally, induced excreted proteins from infected mites but not from uninfected mites stimulate TNF- α and the neutrophil-chemoattractant KC production by antigen-presenting cells (APCs). Altogether, these results describe the modification of the mite behavior under filarial infection and suggest that the immunomodulatory capacity of the mite may be modified by the presence of the parasite, hindering its defensive ability towards the vertebrate host.

  18. Modelling environmental factors correlated with podoconiosis: a geospatial study of non-filarial elephantiasis

    PubMed Central

    2014-01-01

    Introduction The precise trigger of podoconiosis — endemic non-filarial elephantiasis of the lower legs — is unknown. Epidemiological and ecological studies have linked the disease with barefoot exposure to red clay soils of volcanic origin. Histopathology investigations have demonstrated that silicon, aluminium, magnesium and iron are present in the lower limb lymph node macrophages of both patients and non-patients living barefoot on these clays. We studied the spatial variation (variations across an area) in podoconiosis prevalence and the associated environmental factors with a goal to better understanding the pathogenesis of podoconiosis. Methods Fieldwork was conducted from June 2011 to February 2013 in 12 kebeles (administrative units) in northern Ethiopia. Geo-located prevalence data and soil samples were collected and analysed along with secondary geological, topographic, meteorological and elevation data. Soil data were analysed for chemical composition, mineralogy and particle size, and were interpolated to provide spatially continuous information. Exploratory, spatial, univariate and multivariate regression analyses of podoconiosis prevalence were conducted in relation to primary (soil) and secondary (elevation, precipitation, and geology) covariates. Results Podoconiosis distribution showed spatial correlation with variation in elevation and precipitation. Exploratory analysis identified that phyllosilicate minerals, particularly clay (smectite and kaolinite) and mica groups, quartz (crystalline silica), iron oxide, and zirconium were associated with podoconiosis prevalence. The final multivariate model showed that the quantities of smectite (RR = 2.76, 95% CI: 1.35, 5.73; p = 0.007), quartz (RR = 1.16, 95% CI: 1.06, 1.26; p = 0.001) and mica (RR = 1.09, 95% CI: 1.05, 1.13; p < 0.001) in the soil had positive associations with podoconiosis prevalence. Conclusions More quantities of smectite, mica and quartz within the soil

  19. Modelling environmental factors correlated with podoconiosis: a geospatial study of non-filarial elephantiasis.

    PubMed

    Molla, Yordanos B; Wardrop, Nicola A; Le Blond, Jennifer S; Baxter, Peter; Newport, Melanie J; Atkinson, Peter M; Davey, Gail

    2014-06-20

    The precise trigger of podoconiosis - endemic non-filarial elephantiasis of the lower legs - is unknown. Epidemiological and ecological studies have linked the disease with barefoot exposure to red clay soils of volcanic origin. Histopathology investigations have demonstrated that silicon, aluminium, magnesium and iron are present in the lower limb lymph node macrophages of both patients and non-patients living barefoot on these clays. We studied the spatial variation (variations across an area) in podoconiosis prevalence and the associated environmental factors with a goal to better understanding the pathogenesis of podoconiosis. Fieldwork was conducted from June 2011 to February 2013 in 12 kebeles (administrative units) in northern Ethiopia. Geo-located prevalence data and soil samples were collected and analysed along with secondary geological, topographic, meteorological and elevation data. Soil data were analysed for chemical composition, mineralogy and particle size, and were interpolated to provide spatially continuous information. Exploratory, spatial, univariate and multivariate regression analyses of podoconiosis prevalence were conducted in relation to primary (soil) and secondary (elevation, precipitation, and geology) covariates. Podoconiosis distribution showed spatial correlation with variation in elevation and precipitation. Exploratory analysis identified that phyllosilicate minerals, particularly clay (smectite and kaolinite) and mica groups, quartz (crystalline silica), iron oxide, and zirconium were associated with podoconiosis prevalence. The final multivariate model showed that the quantities of smectite (RR = 2.76, 95% CI: 1.35, 5.73; p = 0.007), quartz (RR = 1.16, 95% CI: 1.06, 1.26; p = 0.001) and mica (RR = 1.09, 95% CI: 1.05, 1.13; p < 0.001) in the soil had positive associations with podoconiosis prevalence. More quantities of smectite, mica and quartz within the soil were associated with podoconiosis prevalence. Together with previous

  20. Galactosylated Fucose Epitopes in Nematodes

    PubMed Central

    Yan, Shi; Bleuler-Martinez, Silvia; Plaza, David Fernando; Künzler, Markus; Aebi, Markus; Joachim, Anja; Razzazi-Fazeli, Ebrahim; Jantsch, Verena; Geyer, Rudolf; Wilson, Iain B. H.; Paschinger, Katharina

    2012-01-01

    The modification of α1,6-linked fucose residues attached to the proximal (reducing-terminal) core N-acetylglucosamine residue of N-glycans by β1,4-linked galactose (“GalFuc” epitope) is a feature of a number of invertebrate species including the model nematode Caenorhabditis elegans. A pre-requisite for both core α1,6-fucosylation and β1,4-galactosylation is the presence of a nonreducing terminal N-acetylglucosamine; however, this residue is normally absent from the final glycan structure in invertebrates due to the action of specific hexosaminidases. Previously, we have identified two hexosaminidases (HEX-2 and HEX-3) in C. elegans, which process N-glycans. In the present study, we have prepared a hex-2;hex-3 double mutant, which possesses a radically altered N-glycomic profile. Whereas in the double mutant core α1,3-fucosylation of the proximal N-acetylglucosamine was abolished, the degree of galactosylation of core α1,6-fucose increased, and a novel Galα1,2Fucα1,3 moiety attached to the distal core N-acetylglucosamine residue was detected. Both galactosylated fucose moieties were also found in two parasitic nematodes, Ascaris suum and Oesophagostomum dentatum. As core modifications of N-glycans are known targets for fungal nematotoxic lectins, the sensitivity of the C. elegans double hexosaminidase mutant was assessed. Although this mutant displayed hypersensitivity to the GalFuc-binding lectin CGL2 and the N-acetylglucosamine-binding lectin XCL, the mutant was resistant to CCL2, which binds core α1,3-fucose. Thus, the use of C. elegans mutants aids the identification of novel N-glycan modifications and the definition of in vivo specificities of nematotoxic lectins with potential as anthelmintic agents. PMID:22733825

  1. WormBase: Annotating many nematode genomes.

    PubMed

    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.

  2. Nematode molecular diagnostics: from bands to barcodes.

    PubMed

    Powers, Tom

    2004-01-01

    Nematodes are considered among the most difficult animals to identify. DNA-based diagnostic methods have already gained acceptance in applications ranging from quarantine determinations to assessments of biodiversity. Researchers are currently in an information-gathering mode, with intensive efforts applied to accumulating nucleotide sequence of 18S and 28S ribosomal genes, internally transcribed spacer regions, and mitochondrial genes. Important linkages with collateral data such as digitized images, video clips and specimen voucher web pages are being established on GenBank and NemATOL, the nematode-specific Tree of Life database. The growing DNA taxonomy of nematodes has lead to their use in testing specific short sequences of DNA as a "barcode" for the identification of all nematode species.

  3. How cellular slime molds evade nematodes.

    PubMed Central

    Kessin, R H; Gundersen, G G; Zaydfudim, V; Grimson, M

    1996-01-01

    We have found a predator-prey association between the social amoeba Dictyostelium discoideum and the free soil living nematode Caenorhabditis elegans. C. elegans feeds on the amoebae and multiplies indefinitely when amoebae are the sole food source. In an environment created from soil, D. discoideum grows and develops, but not in the presence of C. elegans. During development, C. elegans feeds on amoebae until they aggregate and synthesize an extracellular matrix called the slime sheath. After the sheath forms, the aggregate and slug are protected. Adult nematodes ingest Dictyostelium spores, which pass through the gut of the worm without loss of structure and remain viable. Nematodes kill the amoebae but disperse the spores. The sheath that is constructed when the social amoebae aggregate and the spore coats of the individual cells may protect against this predator. Individual amoebae may also protect themselves by secreting compounds that repel nematodes. Images Fig. 1 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:8643493

  4. Conserving and Enhancing Biological Control of Nematodes

    PubMed Central

    Timper, Patricia

    2014-01-01

    Conservation biological control is the modification of the environment or existing practices to protect and enhance antagonistic organisms to reduce damage from pests. This approach to biological control has received insufficient attention compared with inundative applications of microbial antagonists to control nematodes. This review provides examples of how production practices can enhance or diminish biological control of plant-parasitic nematodes and other soilborne pests. Antagonists of nematodes can be enhanced by providing supplementary food sources such as occurs when organic amendments are applied to soil. However, some organic amendments (e.g., manures and plants containing allelopathic compounds) can also be detrimental to nematode antagonists. Plant species and genotype can strongly influence the outcome of biological control. For instance, the susceptibility of the plant to the nematode can determine the effectiveness of control; good hosts will require greater levels of suppression than poor hosts. Plant genotype can also influence the degree of rhizosphere colonization and antibiotic production by antagonists, as well the expression of induced resistance by plants. Production practices such as crop rotation, fallow periods, tillage, and pesticide applications can directly disrupt populations of antagonistic organisms. These practices can also indirectly affect antagonists by reducing their primary nematode host. One of the challenges of conservation biological control is that practices intended to protect or enhance suppression of nematodes may not be effective in all field sites because they are dependent on indigenous antagonists. Ultimately, indicators will need to be identified, such as the presence of particular antagonists, which can guide decisions on where it is practical to use conservation biological control. Antagonists can also be applied to field sites in conjunction with conservation practices to improve the consistency, efficacy, and

  5. Conserving and enhancing biological control of nematodes.

    PubMed

    Timper, Patricia

    2014-06-01

    Conservation biological control is the modification of the environment or existing practices to protect and enhance antagonistic organisms to reduce damage from pests. This approach to biological control has received insufficient attention compared with inundative applications of microbial antagonists to control nematodes. This review provides examples of how production practices can enhance or diminish biological control of plant-parasitic nematodes and other soilborne pests. Antagonists of nematodes can be enhanced by providing supplementary food sources such as occurs when organic amendments are applied to soil. However, some organic amendments (e.g., manures and plants containing allelopathic compounds) can also be detrimental to nematode antagonists. Plant species and genotype can strongly influence the outcome of biological control. For instance, the susceptibility of the plant to the nematode can determine the effectiveness of control; good hosts will require greater levels of suppression than poor hosts. Plant genotype can also influence the degree of rhizosphere colonization and antibiotic production by antagonists, as well the expression of induced resistance by plants. Production practices such as crop rotation, fallow periods, tillage, and pesticide applications can directly disrupt populations of antagonistic organisms. These practices can also indirectly affect antagonists by reducing their primary nematode host. One of the challenges of conservation biological control is that practices intended to protect or enhance suppression of nematodes may not be effective in all field sites because they are dependent on indigenous antagonists. Ultimately, indicators will need to be identified, such as the presence of particular antagonists, which can guide decisions on where it is practical to use conservation biological control. Antagonists can also be applied to field sites in conjunction with conservation practices to improve the consistency, efficacy, and

  6. Interactions between Nematodes and Earthworms: Enhanced Dispersal of Steinernema carpocapsae

    PubMed Central

    Shapiro, D. I.; Berry, E. C.; Lewis, L. C.

    1993-01-01

    Dispersal of the nematode Steinernema carpocapsae (All strain), applied on the top or the bottom of soil columns, was tested in the presence or absence of two earthworm species, Lumbricus terrestris or Aporrectodea trapezoides. Nematode dispersal was estimated after a 2-week period with a bioassay against the greater wax moth, Galleria mellonella. Vertical dispersal of nematodes was increased in the presence of earthworms. When nematodes were placed on the surface of soil columns, significantly more nematodes dispersed to the lower half of the columns when either earthworm species was present than when earthworms were not present. When nematodes were placed on the bottom of soil columns, significantly more nematodes dispersed to the upper half of the columns when L. terrestris was present than when A. trapezoides was present or in the absence of earthworms. Because nematodes were found on the exterior and in the interior of earthworms, nematode dispersal may be enhanced by direct contact with the earthworms. PMID:19279757

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

    PubMed

    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.

  8. Biocontrol: Fungi as Nematode Control Agents

    PubMed Central

    Mankau, R.

    1980-01-01

    The fungal antagonists of nematodes consist of a great variety of organisms belonging to widely divergent orders and families of fungi. They include the nematode-trapping fungi, endoparasitic fungi, parasites of nematode eggs and cysts, and fungi which produce metabolites toxic to nematodes. The diversity, adaptations, and distribution of nematode-destroying fungi and taxonomic problems encountered in their study are reviewed. The importance of nemato-phagous fungi in soil biology, with special emphasis on their relationship to populations of plant-parasitic nematodes, is considered. While predacious fungi have long been investigated as possible biocontrol agents and have often exhibited spectacular results in vitro, their performance in field studies has generated little enthusiasm among nematologists. To date no species has demonstrated control of any plant pest to a degree achieved with nematicides, but recent studies have provided a much clearer concept of possibilities and problems in the applied use of fungal antagonists. The discovery of new species, which appear to control certain pests effectively under specific conditions, holds out some promise that fungi may be utilized as alternatives to chemical control after a more thorough and expanded study of their biology and ecology. PMID:19300699

  9. Molecular evidence on the occurrence of co-infection with Pichia guilliermondii and Wuchereria bancrofti in two filarial endemic districts of India

    PubMed Central

    2014-01-01

    Background Lymphatic filariasis (LF), a vector-borne parasitic disease, is endemic in several parts of India and mostly affects the poor or those with a low-income. The disease results in huge numbers of morbidities, disabilities, and deaths every year. Association of co-infection with other pathogens makes the condition more severe. Although co-infection is becoming a growing area of research, it is yet to emerge as a frontier research topic in filarial research specifically. This study reports the occurrence of a fungal infection in a large number of patients suffering from bancroftian filariasis in two districts of West Bengal, India. Methods Nocturnal blood samples from filarial patients containing parasites and fungus were initially co-cultured, and further the fungus was isolated and characterized. Molecular identification of the isolate was carried out by PCR-based selective amplification and sequencing of highly-conserved D1/D2 region of 26S rDNA, whereas pathogenicity was determined by amplification of the RPS0 gene. A phylogenetic tree was constructed to study the relationship between the isolate and common pathogenic yeasts. The isolate was studied for antibiotic sensitivity, whereas morphological characterization was performed by microscopic techniques. Results The isolate was identified as Pichia guilliermondii and this fungus was found to exist in co-infection with Wuchereria bancrofti in filarial patients. The fungus showed resistance to azole antifungals, griseofulvin, and, amphotericin B, whereas significant susceptibility was evident in cases of nystatin and cycloheximide. A total of 197 out of 222 patients showed this co-infection. Conclusion This study revealed, for the first time, that P. guilliermondii exists as a co-infection in microfilaraemic individuals living in a filarial endemic zone. The findings are important and have relevance to human health, especially for filarial patients. PMID:24708881

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

    PubMed

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

    2015-01-01

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

  11. Influence of Metalaxyl on Three Nematodes of Citrus

    PubMed Central

    Kaplan, David T.

    1983-01-01

    Metalaxyl significantly reduced population of Pratylenchus coffeae, Radopholus similis, and Tylenchulus semipenetrans in roots of Citrus limon (rough lemon) under greenhouse conditions. Postinoculation treatment of rough lemon seedlings was not as effective i n reducing nematode populations as was treatment before inoculation. Fewer nematodes infected metalaxyl-treated roots than nontreated roots. However, incubation of nematodes in metalaxyl did not inhibit nematode motility or their ability to locate and infect roots. Cellular responses to nematode injection differed between treated and nontreated tissues. Metalaxyl appeared to confer nematode contraol by modifying citrus roots such that a normally susceptible rootstock became tolerant. PMID:19295833

  12. Influence of metalaxyl on three nematodes of citrus.

    PubMed

    Kaplan, D T

    1983-07-01

    Metalaxyl significantly reduced population of Pratylenchus coffeae, Radopholus similis, and Tylenchulus semipenetrans in roots of Citrus limon (rough lemon) under greenhouse conditions. Postinoculation treatment of rough lemon seedlings was not as effective i n reducing nematode populations as was treatment before inoculation. Fewer nematodes infected metalaxyl-treated roots than nontreated roots. However, incubation of nematodes in metalaxyl did not inhibit nematode motility or their ability to locate and infect roots. Cellular responses to nematode injection differed between treated and nontreated tissues. Metalaxyl appeared to confer nematode contraol by modifying citrus roots such that a normally susceptible rootstock became tolerant.

  13. Nematode Trophic Structure in Conventional and No-Tillage Agroecosystems

    PubMed Central

    Parmelee, Robert W.; Alston, Diane G.

    1986-01-01

    The effect of tillage intensity on nematode community trophic structure and the role of nematodes in the regulation of decomposition rates in agroecosystems were examined. Conventional (CT) and no-tillage (NT) agroecosystems were sampled monthly for 1 year. Tillage affected nematode trophic structure and total abundance. Monthly mean densities of bacterivorous, fungivorous, and total nematodes were greater in CT than in NT plots. In the summer, however, fungivorous and plant parasitic nematodes were more abundant in NT. No difference was detected for omnivore-predator nematodes. PMID:19294199

  14. Induced resistance to nematodes in cotton: a novel contribution to nematode management.

    USDA-ARS?s Scientific Manuscript database

    Induced resistance against plant-parasitic nematodes has not previously been shown in cotton. We tested whether co-infection of cotton by Meloidogyne incognita and Rotylenchulus reniformis affected population levels of either nematode compared to single-species infection. In split-root experiments, ...

  15. Does 24bp Duplication of Human CHIT1 Gene (Chitotriosidase1) Predispose to Filarial Chyluria? A Case-Control Study

    PubMed Central

    Pant, Shriya; Agarwal, Jyotsna; Gangwar, Pravin K; Waseem, Mohammad; Gupta, Prashant; Sankhwar, Satya N; Purkait, Bimalesh

    2016-01-01

    Introduction Chyluria which is endemic in many parts of the world is mainly caused by Wuchereria bancrofti. CHIT1 (chitotriosidase) is produced by macrophages and plays an important role in the defense against chitin containing pathogen such as filarial parasite. Variation in the coding region with 24 bp duplication allele results in reduced CHIT1 activity that enhance the survival of parasite which may play a role in the occurrence of disease. Aim To examine the role of 24bp duplication of CHIT1 gene in patients of filarial chyluria (FC). Materials and Methods A case-control study was carried out where 155 confirmed FC patients and equal number of age-, sex- and residence-matched controls without any symptoms or signs of lymphatic filariasis, confirmed by negative immunochromatographic card test (ICT) and IgG/IgM combo rapid antibody test, from a hospital-based population were enrolled. Filarial aetiology was confirmed on the basis of DEC-provocative test (Giemsa staining), ICT and IgG/IgM- antifiarial antibody test. The patients positive by either of these tests were enrolled as FC cases. 24bp duplication in CHIT1 gene in FC was detected by the product size 99bp of amplified gene using polymerase chain reaction. Results The mean ages of patients and controls were 38.25±12.09 and 35.45±12.53 years, respectively while male: female ratio was 2.4:1. The mean duration of illness in chyluria patients was 62.81±60.83 months and mean number of episodes was 2.54±1.11. Homozygous wild type, heterozygous and homozygous mutant frequencies were 10.3%, 81.3% and 8.4% in FC patients and 18.7%, 75.5%, and 5.8% in controls, respectively. The 24bp duplication in CHIT1 gene showed a significant association in Heterozygous (HT) genotype with Odd Ratio (OR) of 1.95, 95% Confidence Interval (CI) (1.01-3.77); p=0.04. However, the homozygous mutant genotype (TT) was found to be non-significant with OR of 2.61, 95% CI (0.91-7.45); p=0.07. The combination of both HT+TT was also found

  16. Characterization of the Ca2+-Gated and Voltage-Dependent K+-Channel Slo-1 of Nematodes and Its Interaction with Emodepside

    PubMed Central

    Kulke, Daniel; von Samson-Himmelstjerna, Georg; Miltsch, Sandra M.; Wolstenholme, Adrian J.; Jex, Aaron R.; Gasser, Robin B.; Ballesteros, Cristina; Geary, Timothy G.; Keiser, Jennifer; Townson, Simon; Harder, Achim; Krücken, Jürgen

    2014-01-01

    The cyclooctadepsipeptide emodepside and its parent compound PF1022A are broad-spectrum nematicidal drugs which are able to eliminate nematodes resistant to other anthelmintics. The mode of action of cyclooctadepsipeptides is only partially understood, but involves the latrophilin Lat-1 receptor and the voltage- and calcium-activated potassium channel Slo-1. Genetic evidence suggests that emodepside exerts its anthelmintic activity predominantly through Slo-1. Indeed, slo-1 deficient Caenorhabditis elegans strains are completely emodepside resistant. However, direct effects of emodepside on Slo-1 have not been reported and these channels have only been characterized for C. elegans and related Strongylida. Molecular and bioinformatic analyses identified full-length Slo-1 cDNAs of Ascaris suum, Parascaris equorum, Toxocara canis, Dirofilaria immitis, Brugia malayi, Onchocerca gutturosa and Strongyloides ratti. Two paralogs were identified in the trichocephalids Trichuris muris, Trichuris suis and Trichinella spiralis. Several splice variants encoding truncated channels were identified in Trichuris spp. Slo-1 channels of trichocephalids form a monophyletic group, showing that duplication occurred after the divergence of Enoplea and Chromadorea. To explore the function of a representative protein, C. elegans Slo-1a was expressed in Xenopus laevis oocytes and studied in electrophysiological (voltage-clamp) experiments. Incubation of oocytes with 1-10 µM emodepside caused significantly increased currents over a wide range of step potentials in the absence of experimentally increased intracellular Ca2+, suggesting that emodepside directly opens C. elegans Slo-1a. Emodepside wash-out did not reverse the effect and the Slo-1 inhibitor verruculogen was only effective when applied before, but not after, emodepside. The identification of several splice variants and paralogs in some parasitic nematodes suggests that there are substantial differences in channel properties among

  17. Characterization of the Ca2+-gated and voltage-dependent K+-channel Slo-1 of nematodes and its interaction with emodepside.

    PubMed

    Kulke, Daniel; von Samson-Himmelstjerna, Georg; Miltsch, Sandra M; Wolstenholme, Adrian J; Jex, Aaron R; Gasser, Robin B; Ballesteros, Cristina; Geary, Timothy G; Keiser, Jennifer; Townson, Simon; Harder, Achim; Krücken, Jürgen

    2014-12-01

    The cyclooctadepsipeptide emodepside and its parent compound PF1022A are broad-spectrum nematicidal drugs which are able to eliminate nematodes resistant to other anthelmintics. The mode of action of cyclooctadepsipeptides is only partially understood, but involves the latrophilin Lat-1 receptor and the voltage- and calcium-activated potassium channel Slo-1. Genetic evidence suggests that emodepside exerts its anthelmintic activity predominantly through Slo-1. Indeed, slo-1 deficient Caenorhabditis elegans strains are completely emodepside resistant. However, direct effects of emodepside on Slo-1 have not been reported and these channels have only been characterized for C. elegans and related Strongylida. Molecular and bioinformatic analyses identified full-length Slo-1 cDNAs of Ascaris suum, Parascaris equorum, Toxocara canis, Dirofilaria immitis, Brugia malayi, Onchocerca gutturosa and Strongyloides ratti. Two paralogs were identified in the trichocephalids Trichuris muris, Trichuris suis and Trichinella spiralis. Several splice variants encoding truncated channels were identified in Trichuris spp. Slo-1 channels of trichocephalids form a monophyletic group, showing that duplication occurred after the divergence of Enoplea and Chromadorea. To explore the function of a representative protein, C. elegans Slo-1a was expressed in Xenopus laevis oocytes and studied in electrophysiological (voltage-clamp) experiments. Incubation of oocytes with 1-10 µM emodepside caused significantly increased currents over a wide range of step potentials in the absence of experimentally increased intracellular Ca2+, suggesting that emodepside directly opens C. elegans Slo-1a. Emodepside wash-out did not reverse the effect and the Slo-1 inhibitor verruculogen was only effective when applied before, but not after, emodepside. The identification of several splice variants and paralogs in some parasitic nematodes suggests that there are substantial differences in channel properties among

  18. Interspecific Nematode Signals Regulate Dispersal Behavior

    PubMed Central

    Kaplan, Fatma; Alborn, Hans T.; von Reuss, Stephan H.; Ajredini, Ramadan; Ali, Jared G.; Akyazi, Faruk; Stelinski, Lukasz L.; Edison, Arthur S.; Schroeder, Frank C.; Teal, Peter E.

    2012-01-01

    Background Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2) of plant parasitic Meloidogyne spp. and infective juveniles (IJ)s of entomopathogenic nematodes (EPN), e.g., Steinernema feltiae. Regulation of dispersal behavior has not been thoroughly investigated for C. elegans or any other nematode species. Based on the fact that ascarosides regulate entry in dauer stage as well as multiple behaviors in C. elegans adults including mating, avoidance and aggregation, we hypothesized that ascarosides might also be involved in regulation of dispersal behavior in C. elegans and for other nematodes such as IJ of phylogenetically related EPNs. Methodology/Principal Findings Liquid chromatography-mass spectrometry analysis of C. elegans dauer conditioned media, which shows strong dispersing activity, revealed four known ascarosides (ascr#2, ascr#3, ascr#8, icas#9). A synthetic blend of these ascarosides at physiologically relevant concentrations dispersed C. elegans dauer in the presence of food and also caused dispersion of IJs of S. feltiae and J2s of plant parasitic Meloidogyne spp. Assay guided fractionation revealed structural analogs as major active components of the S. feltiae (ascr#9) and C. elegans (ascr#2) dispersal blends. Further analysis revealed ascr#9 in all Steinernema spp. and Heterorhabditis spp. infected insect host cadavers. Conclusions/Significance Ascaroside blends represent evolutionarily conserved, fundamentally important communication systems for nematodes from diverse habitats, and thus may provide sustainable means for control of parasitic nematodes. PMID:22701701

  19. Low positive predictive value of anti-Brugia malayi IgG and IgG4 serology for the diagnosis of Wuchereria bancrofti.

    PubMed

    Chanteau, S; Glaziou, P; Moulia-Pelat, J P; Plichart, C; Luquiaud, P; Cartel, J L

    1994-01-01

    Enzyme-linked immunosorbent assays (ELISAs) for anti-Brugia malayi immunoglobulin (Ig) G and IgG4 were evaluated on sera from 1561 subjects in French Polynesia for the serodiagnosis of Wuchereria bancrofti filariasis, compared with the test for Onchocerca gibsoni circulating antigen (Og4C3) as a 'gold standard'. The sensitivity of the ELISA-IgG and ELISA-IgG4 assays was 90.8% and 94.5%, and the specificity was 45.9% and 50.7%. The positive predictive values were 41% and 45% respectively for an antigen prevalence rate of 30%. Thus antibody prevalences exceeded by two-fold the antigen prevalence, which itself exceeded by two-fold the prevalence of microfilaraemia.

  20. Designing, synthesis of selective and high-affinity chalcone-benzothiazole hybrids as Brugia malayi thymidylate kinase inhibitors: In vitro validation and docking studies.

    PubMed

    Sashidhara, Koneni V; Avula, Srinivasa Rao; Doharey, Pawan Kumar; Singh, L Ravithej; Balaramnavar, Vishal M; Gupta, Jyoti; Misra-Bhattacharya, Shailja; Rathaur, Sushma; Saxena, Anil K; Saxena, Jitendra Kumar

    2015-10-20

    In our continuing search for safe and efficacious antifilarials, a series of novel chalcone-benzothiazole hybrids have been synthesized and evaluated for their Brugia malayi thymidylate kinase (BmTMK) enzyme inhibition activity. Their selectivity towards BmTMK was studied and compared to the human TMK (HsTMK) by an in silico method. Out of seventeen derivatives, compounds 34 and 42 showed higher interactions with the BmTMK active site. MolDock docking model revealed the interactions of these two derivatives and the results corroborated well with their in vitro antifilarial activities. Our studies suggest that these hybrids are selective towards the BmTMK enzyme and may serve as potential therapeutic agents against filariasis.

  1. Embryological variation during nematode development.

    PubMed

    Schierenberg, Einhard

    2006-01-02

    Early cell lineages and arrangement of blastomeres in C. elegans are similar to the pattern found in Ascaris and other studied nematodes leading to the assumption that embryonic development shows little variation within the phylum Nematoda. However, analysis of a larger variety of species from various branches of the phylogenetic tree demonstrate that prominent variations in crucial steps of early embryogenesis exist among representatives of this taxon. So far, most of these variations have only been studied on a descriptive level and thus essentially nothing is known about their molecular or genetic basis. Nevertheless, it is obvious that the limited morphological diversity of the freshly hatched juvenile and the uniformity of the basic body plan contrast with the many modifications in the way a worm is generated from the egg cell. This chapter focuses on the initial phase between egg activation and gastrulation and deals with the following aspects: reproduction and diploidy, polarity, cleavage and germ line, cell lineages; cell cycles and maternal contribution, cell-cell communication and cell specification, gastrulation.

  2. An unidentified filarial species and its impact on fitness in wild populations of the black-footed ferret (Mustela nigripes).

    PubMed

    Wisely, Samantha M; Howard, JoGayle; Williams, Steven A; Bain, Odile; Santymire, Rachel M; Bardsley, Katherine D; Williams, Elizabeth S

    2008-01-01

    Disease can threaten the restoration of endangered species directly by substantially decreasing host survival or indirectly via incremental decreases in survival and reproduction. During a biomedical survey of reintroduced populations of the highly endangered black-footed ferret from 2002 to 2005, microfilariae discovered in the blood were putatively identified as Dirofilaria immitis, and widespread screening was initiated using a commercially available antigen-based ELISA test. A subset of animals (n = 16) was screened for D. immitis using a highly sensitive PCR-based assay. Microfilariae were also molecularly and morphologically characterized. Of 198 animals at six reintroduction sites, 12% had positive results using the ELISA test. No antigen-positive animals which were screened via PCR (n = 11) had positive PCR results, and all antigen-positive animals (n = 24) were asymptomatic. No significant differences were found in body mass of antigen-positive (male: 1223 +/- 82 g [mean +/- SD], female: 726 +/- 75 g) vs. antigen-negative (male: 1,198 +/- 119 g, female: 710 +/- 53 g) individuals (P = 0.4). Antigen prevalence was lower in juveniles (3%) than adults (12%; P = 0.03), and higher in in situ, captive-reared individuals (33%) than wild-born individuals (10%; P = 0.005). Morphologic analysis of microfilariae revealed they were neither D. immitis nor any other previously characterized North American species. PCR amplification of the 5S spacer region of rDNA revealed that the filarial sequence shared only 76% identity with D. immitis. This previously unidentified filarial sequence was present in all antigen positive animals (11 of 11 tested). It appears that black-footed ferrets were infected with a previously undescribed species of filaria whose antigen cross-reacted with the ELISA assay, although further analysis is needed to make a conclusive statement. Nonetheless, this previously undescribed filaria does not appear to threaten recovery for this highly

  3. Brugia pahangi: immunization with early L3 ES alters parasite migration, and reduces microfilaremia and lymphatic lesion formation in gerbils (Meriones unguiculatus).

    PubMed

    Zipperer, Ginger R; Arumugam, Sridhar; Chirgwin, Sharon R; Coleman, Sharon U; Shakya, Krishna P; Klei, Thomas R

    2013-10-01

    Previous studies have shown that intradermally (ID) injected Brugia pahangi L3 s migrate through various tissues and into the lymphatics of gerbils in a distinct pattern. Excretory/secretory products (ES) produced at the time of invasion of B. pahangi are likely to be important in this early migration phase of the parasite life cycle in their rodent host. Hence, early L3 ES was collected from 24h in vitro cultures of B. pahangi L3 larvae and used in immunization experiments to investigate the effect of immunity to early L3 ES on worm migration, survival and development of B. pahangi. Immunization of gerbils with ES in RIBI adjuvant produced antibodies to numerous ES proteins eliciting a strong humoral response to ES and indirect fluorescent antibody (IFA) assay using anti-ES serum recognized the ES proteins on the surface of B. pahangi L3 larvae. Following ES immunization, gerbils were challenged either ID or intraperitoneally (IP) with 100 L3 s of B. pahangi and euthanized at 3 or 106 days post inoculation (DPI). Immunization with early ES slowed the migration of ID inoculated L3 at 3 DPI and significantly altered the locations of adult worms at 106 DPI. Immunization did not induce protection in any treatment group. However, immunized animals had significantly fewer microfilariae per female worm suggesting the antigens in ES are important in microfilariae development or survival in the host. The number of lymphatic granulomas was also significantly reduced in ES immunized animals. It is important to note that microfilariae serve as a nidus in these granulomas. Our results shows immunization with early Brugia malayi L3 ES alters the worm migration, affects circulating microfilarial numbers and reduces lymphatic granulomas associated with B. pahangi infection in gerbils.

  4. Wolbachia lipoproteins: abundance, localisation and serology of Wolbachia peptidoglycan associated lipoprotein and the Type IV Secretion System component, VirB6 from Brugia malayi and Aedes albopictus.

    PubMed

    Voronin, Denis; Guimarães, Ana F; Molyneux, Gemma R; Johnston, Kelly L; Ford, Louise; Taylor, Mark J

    2014-10-06

    Lipoproteins are the major agonists of Wolbachia-dependent inflammatory pathogenesis in filariasis and a validated target for drug discovery. Here we characterise the abundance, localisation and serology of the Wolbachia lipoproteins: Wolbachia peptidoglycan associated lipoprotein and the Type IV Secretion System component, VirB6. We used proteomics to confirm lipoprotein presence and relative abundance; fractionation, immunoblotting and confocal and electron immuno-microscopy for localisation and ELISA for serological analysis. Proteomic analysis of Brugia malayi adult female protein extracts confirmed the presence of two lipoproteins, previously predicted through bioinformatics: Wolbachia peptidoglycan associated lipoprotein (wBmPAL) and the Type IV Secretion System component, VirB6 (wBmVirB6). wBmPAL was among the most abundant Wolbachia proteins present in an extract of adult female worms with wBmVirB6 only detected at a much lower abundance. This differential abundance was reflected in the immunogold-labelling, which showed wBmPAL localised at numerous sites within the bacterial membranes, whereas wBmVirB6 was present as a single cluster on each bacterial cell and also located within the bacterial membranes. Immunoblotting of fractionated extracts confirmed the localisation of wBmPAL to membranes and its absence from cytosolic fractions of C6/36 mosquito cells infected with wAlbB. In whole worm mounts, antibody labelling of both lipoproteins were associated with Wolbachia. Serological analysis showed that both proteins were immunogenic and raised antibody responses in the majority of individuals infected with Wuchereria bancrofti. Two Wolbachia lipoproteins, wBmPAL and wBmVirB6, are present in extracts of Brugia malayi with wBmPAL among the most abundant of Wolbachia proteins. Both lipoproteins localised to bacterial membranes with wBmVirB6 present as a single cluster suggesting a single Type IV Secretory System on each Wolbachia cell.

  5. Parameters affecting plant defense pathway mediated recruitment of entomopathogenic nematodes

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes are natural enemies and effective biological control agents of subterranean insect herbivores. Interactions between her bivores, plants, and entomopathogenic nematodes are mediated by plant defense pathways that can induce release of volatiles that recruit entomopathogenic...

  6. Two new species of soil nematodes from Manipur, India.

    PubMed

    Chanu, Loukrakpam Bina; Meitei, N Mohilal; Shah, M Manjur

    2016-09-01

    Survey for soil nematodes associated with mulberry plants in valley districts of Manipur revealed the presence of two new species of soil nematodes of the genus Tylenchus sp. and Telotylenchus sp. The two new species are described and illustrated here.

  7. Nematodes associated with blackberry in arkansas.

    PubMed

    Wehunt, E J; Golden, A M; Clark, J R; Kirkpatrick, T L; Baker, E C; Brown, M A

    1991-10-01

    A survey of the nematodes in blackberry (Rubus sp.) rhizospheres was conducted in Arkansas from 1986 to 1989. The state was divided arbitrarily into four quadrants. A total of 134 soil samples was collected, and 150-cm 3 subsamples were assayed for nematodes. Twenty-one species of plant-parasitic nematodes in 11 genera were extracted from the samples. There were differences (P = 0.05) among quadrants of the state in percentage occurrence of the nematodes and in population densities in samples. Xiphinema americanum, Helicotylenchus spp. (H. paraplatyurus, H. platyurus, and H. pseudorobustus), and Pratylenchus spp. (P. vulnus and P. zeae) were found in all quadrants. Xiphinema americanum population density was near 1,000 per 150 cm(3) soil in soil samples from two locations. Other nematodes found in one or more quadrants were Criconemella spp. (C. axeste, C. curvata, C. denoudeni, C. ornata, C. sphaerocephala, and C. xenoplax), Paratrichodorus minor, Tylenchorhynchus claytoni, Hirschmanniella oryzae, Hoplolaimus magnistylus, Scutellonema bradys, and undescribed species of Criconema, Tylenchulus, Xiphinema, and Meloidogyne. Criconemella sphaerocephala and Helicotylenchus platyurus are reported from Arkansas for the first time. Helicotylenchus paraplatyurus is reported from the United States for the first time.

  8. Molecular Transfer of Nematode Resistance Genes

    PubMed Central

    Williamson, V. M.; Ho, J.-Y.; Ma, H. M.

    1992-01-01

    Recombinant DNA techniques have been used to introduce agronomically valuable traits, including resistance to viruses, herbicides, and insects, into crop plants. Introduction of these genes into plants frequently involves Agrobacterium-mediated gene transfer. The potential exists for applying this technology to nematode control by introducing genes conferring resistance to nematodes. Transferred genes could include those encoding products detrimental to nematode development or reproduction as well as cloned host resistance genes. Host genes that confer resistance to cyst or root-knot nematode species have been identified in many plants. The best characterized is Mi, a gene that confers resistance to root-knot nematodes in tomato. A map-based cloning approach is being used to isolate the gene. For development of a detailed map of the region of the genome surrounding Mi, DNA markers genetically linked to Mi have been identified and analyzed in tomato lines that have undergone a recombination event near Mi. The molecular map will be used to identify DNA corresponding to Mi. We estimate that a clone of Mi will be obtained in 2-5 years. An exciting prospect is that introduction of this gene will confer resistance in plant species without currently available sources of resistance. PMID:19282989

  9. Nematode feeding sites: unique organs in plant roots.

    PubMed

    Kyndt, Tina; Vieira, Paulo; Gheysen, Godelieve; de Almeida-Engler, Janice

    2013-11-01

    Although generally unnoticed, nearly all crop plants have one or more species of nematodes that feed on their roots, frequently causing tremendous yield losses. The group of sedentary nematodes, which are among the most damaging plant-parasitic nematodes, cause the formation of special organs called nematode feeding sites (NFS) in the root tissue. In this review we discuss key metabolic and cellular changes correlated with NFS development, and similarities and discrepancies between different types of NFS are highlighted.

  10. Nature and Inheritance of Nematode Resistance in Cereals

    PubMed Central

    Cook, R.

    1974-01-01

    Resistance to a number of nematodes is present in varieties of temperate and tropical cereals. The occurrence, nature, and inheritance of varietal resistance in cereals is reviewed. Evaluation of the practical significance of nematode resistance in a particular host-nematode combination is discussed in relation to host efficiency, host sensitivity, genetic control of resistance, and presence of virulence in the nematode population. PMID:19308117

  11. Biocontrol: the potential of entomophilic nematodes in insect management.

    PubMed

    Webster, J M

    1980-10-01

    A review of the development of entomophilic nematology and a commentary on the potential of entomophilic nematodes in controlling insect pests. The paper considers some of the major contributions to our knowledge of entomophilic nematology; factors involved in insect pest management and how they are applicable to the use of nematodes; nematodes which are most promising as biological control agents; and problems to be solved to facilitate the use of entomophilic nematodes in insect management.

  12. Biocontrol: The Potential of Entomophilic Nematodes in Insect Management

    PubMed Central

    Webster, John M.

    1980-01-01

    A review of the development of entomophilic nematology and a commentary on the potential of entomophilic nematodes in controlling insect pests. The paper considers some of the major contributions to our knowledge of entomophilic nematology; factors involved in insect pest management and how they are applicable to the use of nematodes; nematodes which are most promising as biological control agents; and problems to be solved to facilitate the use of entomophilic nematodes in insect management. PMID:19300702

  13. Characterization of biocontrol traits in the entomopathogenic nematode Heterorhabditis georgiana (Kesah strain), and phylogenetic analysis of the nematode's symbiotic bacteria.

    USDA-ARS?s Scientific Manuscript database

    Our objective was to estimate the biocontrol potential of the recently discovered entomopathogenic nematode species, Heterorhabditis georgiana (Kesha strain). Virulence and environmental tolerance were tested among several nematode species. Heterorhabditis georgiana expressed low or intermediate c...

  14. Site-Specific Detection and Management of Nematodes

    USDA-ARS?s Scientific Manuscript database

    Nematode distribution varies significantly throughout a field and is highly correlated to soil texture and other edaphic factors. Field-wide application results in nematicides being applied to areas without nematodes and the application of sub-effective levels in areas with high nematode densities. ...

  15. Bacterial microbiome and nematode occurrence in different potato agricultural soils

    USDA-ARS?s Scientific Manuscript database

    Pratylenchus neglectus and Meloidogyne chitwoodi are the main plant-parasitic nematodes in potato crops of the San Luis Valley, Colorado. Bacterial microbiome (16S rRNA copies per gram of soil) and nematode communities (nematodes per 200 gr of soil) from five different potato farms were analyzed to ...

  16. Ecology of the Pinewood Nematode in Southern Pine Chip Piles

    Treesearch

    L. David Dwinell

    1986-01-01

    The optimum temperature range for pinewood nematodes in southern pine chips was 35 to 40° C. Nematode populations declined at temperatures of -20°C. at temperatures above 45°C. and in anaerobic environments. Wood moisture content and presence of bluestain fungus also influenced nematode populations.

  17. Opportunity to use native nematodes for pest control

    USDA-ARS?s Scientific Manuscript database

    We have surveyed wild cranberry bogs in WI and found three isolates of native nematodes. We have been testing these nematodes as potential biological control agents in for cranberry insect pests including sparganothis fruitworm and flea beetle. The nematodes seem to be effective at finding and killi...

  18. Towards a genome sequence for reniform nematode (Rotylenchulus reniformis)

    USDA-ARS?s Scientific Manuscript database

    Reniform nematode (Rotylenchulus reniformis) currently accounts for $130M in annual losses to the U.S. cotton industry and has supplanted root-knot nematode as the major nematode pest of cotton in Mississippi, Louisiana, and Alabama. Moreover, in other cotton-producing states the range and influenc...

  19. Nematode CLE signaling in Arabidopsis requires CLAVATA2 and CORYNE

    USDA-ARS?s Scientific Manuscript database

    Plant-parasitic cyst nematodes secrete CLAVATA3 (CLV3)/ESR(CLE)-like effector proteins. These proteins have been shown to act as ligand mimics of plant CLE peptides and are required for successful nematode infection; however, the receptors for nematode CLE-like peptides have not been identified. Her...

  20. A novel flavivirus in the soybean cyst nematode

    USDA-ARS?s Scientific Manuscript database

    Heterodera glycines, the soybean cyst nematode (SCN) is a subterranean root pathogen that causes the most damaging disease of soybean in the United States. A novel nematode virus genome, soybean cyst nematode virus 5 (SbCNV5), was identified in RNASeq data from SCN eggs and second-stage juveniles. T...

  1. Nematode Problems Affecting Agriculture in the Philippines

    PubMed Central

    Davide, R. G.

    1988-01-01

    Nematodes are considered major pests on most economic crops in the Philippines, particularly on banana, pineapple, citrus, tomato, ramie, and sugarcane. Radopholus similis is the most destructive