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Sample records for parasite setaria cervi

  1. Identification and characterization of novel membrane-bound PRL protein tyrosine phosphatases from Setaria cervi, a bovine filarial parasite.

    PubMed

    Singh, Neetu; Yadav, Smita; Rathaur, Sushma

    2015-11-01

    A significant amount of protein tyrosine phosphatase (PTP) activity was detected in the detergent-soluble membrane-bound fraction of Setaria cervi, a bovine filarial parasite. The membrane-bound PTP activity was significantly inhibited when the adult parasites were exposed to compounds having antifilarial activity like aspirin and SK7 as well as phenylarsine oxide, a specific PTP inhibitor suggesting that this activity is stress regulated. Further, this enzyme was purified as a single protein of apparently 21 kDa using two different chromatographic techniques. The MALDI-MS/MS analysis of its peptides showed closest match with protein tyrosine phosphatase PRL (Aedes aegypti). This purified enzyme (named as PRL) showed maximum activity at pH 5.5/37 °C and hydrolysed para nitro phenyl phosphate (pNPP) at the highest rate followed by O-P-L-tyrosine and O-P-L-threonine. It showed significant inhibition by specific inhibitors of PTP such as sodium orthovanadate, phenylarsine oxide and ammonium molybdate and was activated by dithiothreitol (DTT). The active site modification studies suggested involvement of cysteine, arginine, histidine and aspartic acid in the catalytic activity of PRL. The activity of S. cervi PRL was also found to be resistant towards the external oxidative stress. Thus, S. cervi PRL could be taken as a potential target for the management of human lymphatic filariasis. PMID:26341797

  2. Presence of ecto-protein tyrosine phosphatase activity is vital for survival of Setaria cervi, a bovine filarial parasite.

    PubMed

    Singh, Neetu; Heneberg, Petr; Rathaur, Sushma

    2014-10-01

    The ecto protein tyrosine phosphatases (PTP) are known to play a crucial role in the pathogenesis and survival of the intracellular parasites. However, their presence and role in filarial parasites is still unknown. We found a significant amount of tyrosine phosphatase activity in the surface antigen fraction extracted from Setaria cervi (S. cervi), a bovine filarial parasite. An antibody designed against the conserved catalytic core of human protein tyrosine phosphatases, PTP1B cross reacted with a 63 kDa band in the surface antigen. We detected a significant amount of PTP activity in the intact S. cervi adult parasites as well as microfilariae in this study for the first time. This PTP may be localized on the surface of the parasite with an exposed active site available for the external substrates. The PTP activity was also inhibited by sodium orthovanadate and phenyl arsine oxide, specific inhibitors of PTP in both the life stages. The Km and Vmax for PTP in the adult parasites and microfilariae were determined to be 2.574 ± 0.14 mM; 206.3 ± 2.75 μM Pi/h/two parasites and 5.510 ± 0.59 mM; 62.27 ± 2.27 μM Pi/h/10(6) parasites respectively using O-P-L-Tyrosine as substrate. Interestingly, a positive correlation was observed between the inhibition in PTP activity and reduction in the motility/ viability of the parasites when they were subjected to the specific PTP inhibitors (Orthovanadate and Phenyl arsine oxide) for 4 h in the KRB maintenance medium. The activity was also significantly inhibited in the parasites exposed to antifilarial drug/compounds for e.g. Diethylcarbamazine, Acetylsalicylic Acid and SK7, a methyl chalcone. Therefore suggesting a possible role played by PTP in the survival of the parasite, its interaction with the host as well as in the screening of newly synthesized antifilarials/drugs. PMID:25028209

  3. Copper(II) oxide nanoparticles augment antifilarial activity of Albendazole: In vitro synergistic apoptotic impact against filarial parasite Setaria cervi.

    PubMed

    Zafar, Atif; Ahmad, Irshad; Ahmad, Ajaz; Ahmad, Masood

    2016-03-30

    Mass treatment of lymphatic filariasis with Albendazole (ABZ), a therapeutic benzimidazole, is fraught with serious limitations such as possible drug resistance and poor macrofilaricidal activity. Therefore, we need to develop new ABZ-based formulations to improve its antifilarial effectiveness. CuO nanoparticles were used as an adjuvant with ABZ to form ABZ-CuO nanocomposite, which was characterized by UV-vis spectroscopy, FT-IR, AFM and SEM. Antifilarial activity of nanocomposite was evaluated using relative motility assay and dye exclusion test in dark and under UV light. ROS generation, antioxidant levels, lipid peroxidation and DNA fragmentation in nanocomposite treated parasites were estimated. Biophysical techniques were employed to ascertain the mode of binding of nanocomposite to parasitic DNA. Nanocomposite increases parasite mortality as compared to ABZ in dark, and its antifilarial effect was increased further under UV light. Elevated ROS production and decline of parasitic-GST and GSH levels were observed in nanocomposite treated worms in dark, and these effects were pronounced further under UV light. Nanocomposite leads to higher DNA fragmentation as compared to ABZ alone. Further, we found that nanocomposite binds parasitic DNA in an intercalative manner where it generates ROS to induce DNA damage. Thus, oxidative stress production due to ROS generation and consequent DNA fragmentation leads to apoptosis in worms. This is the first report supporting CuO nanoparticles as a potential adjuvant with ABZ against filariasis along with enhanced antifilarial activity of nanocomposite under UV light. These findings, thus, indicate that development of ABZ-loaded nanoparticle compounds may serve as promising leads for filariasis treatment. PMID:26827921

  4. Purification and characterization of glutathione reductase (E.C. 1.8.1.7) from bovine filarial worms Setaria cervi.

    PubMed

    Arora, Kavita; Ahmad, Rumana; Srivastava, Arvind K

    2013-04-01

    Antioxidant enzymes are the parasite's premier resource to defend themselves against reactive oxygen species generated by macrophages, neutrophils and eosinophils of the host. These enzymes may be particularly important for parasites involved in chronic infections, such as parasitic helminths. Glutathione (GSH) and glutathione reductase (GR) are parts of the GSH redox cycle, which protects cells against damage by oxidants. Both GSH and GR are present in significant amounts in Setaria cervi female worms. GR has a central role in glutathione metabolism and as such is a potential target for chemotherapy. The aim of the work was to purify and characterize GR from S. cervi and to compare the properties of the helminth enzyme with its mammalian counterpart. GR was purified from filarial parasites S. cervi and preliminary steady state kinetics was performed. The purified protein was observed to be a dimer of 55 kDa subunit as evident from SDS-PAGE analysis. Kinetic studies revealed significant differences in the properties of S. cervi GR from its mammalian counterpart which may be exploited in chemotherapy of filariasis. Filarial GR is thus proposed as a potential drug target. PMID:24431548

  5. Inhibition of Setaria cervi protein tyrosine phosphatases by Phenylarsine oxide: A proteomic and biochemical study.

    PubMed

    Singh, Neetu; Wadhawan, Mohit; Tiwari, Savitri; Kumar, Ranjeet; Rathaur, Sushma

    2016-07-01

    Phenylarsine oxide (PAO), a specific protein tyrosine phosphatase (PTP) inhibitor significantly decreased the motility and viability of Setaria cervi ultimately leading to its death. The PTP activity present in the cytosolic and detergent soluble fractions as well as on surface of these parasites was significantly inhibited by PAO. A marked alteration in protein spots abundance after proteomic analysis showed 14 down-regulated and 9 upregulated spots in the treated parasites as compared to the control. The PTP inhibition led to increase in the cytosolic and mitochondrial calpain activity in these parasites. PAO also blocked the ATP generation in the parasite depicted by reduced activity of phosphoglycerate kinase and expression of enolase. An increased ROS level, induced lipid peroxidation/protein carbonyl formation and decreased activity of different antioxidant enzymes like thioredoxin reductase, glutathione reductase and glutathione transferases was also observed in the PAO treated parasites. PAO, thus disturbs the overall homeostasis of the filarial parasite by inhibiting PTPs. Thereby suggesting that these molecules could be used as a good chemotherapeutic target for lymphatic filariasis. PMID:26965172

  6. Identification and characterization of a selenium-dependent glutathione peroxidase in Setaria cervi

    SciTech Connect

    Singh, Anchal; Rathaur, Sushma . E-mail: sushmarathaur@yahoo.com

    2005-06-17

    Setaria cervi a bovine filarial parasite secretes selenium glutathione peroxidase during in vitro cultivation. A significant amount of enzyme activity was detected in the somatic extract of different developmental stages of the parasite. Among different stages, microfilariae showed a higher level of selenium glutathione peroxidase activity followed by males then females. However, when the activity was compared in excretory secretory products of these stages males showed higher activity than microfilariae and female worms. The enzyme was purified from female somatic extract using a combination of glutathione agarose and gel filtration chromatography, which migrated as a single band of molecular mass {approx}20 kDa. Selenium content of purified enzyme was estimated by atomic absorption spectroscopy and found to be 3.5 ng selenium/{mu}g of protein. Further, inhibition of enzyme activity by potassium cyanide suggested the presence of selenium at the active site of enzyme. This is the first report of identification of selenium glutathione peroxidase from any filarial parasite.

  7. Evidence of reactive oxygen species (ROS) mediated apoptosis in Setaria cervi induced by green silver nanoparticles from Acacia auriculiformis at a very low dose.

    PubMed

    Saini, Prasanta; Saha, Swadhin Kr; Roy, Priya; Chowdhury, Pranesh; Sinha Babu, Santi P

    2016-01-01

    Green synthesis of silver nanomaterial plays a pivotal role in the growing field of nanotechnology. Development of anti-parasitic drugs from plant metabolites has been in regular practice from the ancient period but most of them were discarded due to their inefficiency to control diseases effectively. At present, nanoparticles are used for developing anti-parasitic therapy for their unique properties such as smallest in size, bio-ability, bio-compatibility and penetration capacity into a cell. The present study aims at synthesis of silver nanoparticles (AgNPs) by using funicles extract of Acacia auriculiformis and tests its efficacy as antifilarial. Experimental evidence show that AgNPs are effective at a very low concentration compared to crude plant extracts. Synthesis of these nanoparticles is a single-step, biogenic, cost effective and eco-friendly process. Synthesized nanoparticles were characterized by UV-Vis spectroscopy, TEM, SAED, FTIR, EDX, FESEM and Z-potential. The antifilarial efficacy of AgNPs was tested against different life cycle stages of bovine filarial parasite Setaria cervi by morphological study, motility assessment and viability assay. These nanoparticles are found to have antifilarial activity with LC50 of 5.61 μg/mL and LC90 of 15.54 μg/mL against microfilaria of S. cervi. The microscopic findings and the detailed molecular studies confirmed that green synthesized AgNPs were effective enough to induce apoptosis through up regulation of ROS (reactive oxygen species). PMID:26627139

  8. MALDI mass sequencing and biochemical characterization of Setaria cervi protein tyrosine phosphatase.

    PubMed

    Rai, Reeta; Singh, Neetu; Elesela, Srikanth; Tiwari, Savitri; Rathaur, Sushma

    2013-01-01

    A 30-kDa acid phosphatase with protein tyrosine phosphatase activity was identified in Setaria cervi (ScPTP). The enzyme was purified to homogeneity using three-step column chromatography. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis of purified ScPTP yielded a total of eight peptides matching most closely to phosphoprotein phosphatase of Ricinus communis (RcPP). A hydrophilicity plot of RcPP revealed the presence of these peptides in the hydrophilic region, suggesting their antigenic nature. The substrate specificity of ScPTP with ortho-phospho-L-tyrosine and inhibition with sodium orthovanadate and ammonium molybdate affirmed it as a protein tyrosine phosphatase. ScPTP was also found to be tartrate resistant. The Km and Vmax were 6.60 mM and 83.3 μM/ml/min, respectively, with pNPP and 8.0 mM and 111 μM/ml/min, respectively, with ortho-phospho-L-tyrosine as the substrate. The Ki value with sodium orthovanadate was calculated to be 16.10 mM. Active site modification with DEPC, EDAC and pHMB suggested the presence of histidine, cysteine and aspartate at its active site. Thus, on the basis of MALDI-TOF and biochemical studies, it was confirmed that purified acid phosphatase is a PTP. PMID:23052758

  9. Antifilarial effects of polyphenol rich ethanolic extract from the leaves of Azadirachta indica through molecular and biochemical approaches describing reactive oxygen species (ROS) mediated apoptosis of Setaria cervi.

    PubMed

    Mukherjee, Niladri; Mukherjee, Suprabhat; Saini, Prasanta; Roy, Priya; Sinha Babu, Santi P

    2014-01-01

    Lymphatic filariasis, a global cause of morbidity needs much more attention in developing potent therapeutics that can be effective against both microfilariae (mf) and adults. Efficient botanicals that can induce apoptosis of filarial parasites possibly can provide a direction towards developing new class of antifilarials. In this work we have evaluated the antifilarial efficacy of an optimized polyphenol rich ethanolic extract of Azadirachta indica leaves (EEA). A. indica A. Juss has been widely used in the traditional Indian medicinal system 'Ayurveda' for the treatment of a variety of ailments. A thorough investigation towards biochemical and molecular mechanisms describing ROS mediated apoptosis in Setaria cervi was performed. Motility reduction, MTT reduction assay and dye exclusion test have confirmed the micro- and macrofilaricidal potential of EEA. Alterations were visible in mf and trichrome stained section of EEA-treated adult worms. We have found cellular disturbances in EEA-treated parasites characterized by chromatin condensation, in situ DNA fragmentation and nucleosomal DNA laddering. Depletion in worm GSH level and elevation in parasite GST, SOD, catalase, GPx and superoxide anion indicated the generation of ROS. Our results provided experimental evidence supporting that EEA causes a decreased expression of anti-apoptotic genes and increased pro-apoptotic gene expression at the level of both transcription and translation. Here we are reporting for the first time that antifilarial activity of EEA is mediated by ROS up regulation and apoptosis. PMID:24275557

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

    PubMed

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

    2014-09-01

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

  11. 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

  12. Vectors and transmission dynamics for Setaria tundra (Filarioidea; Onchocercidae), a parasite of reindeer in Finland

    PubMed Central

    Laaksonen, Sauli; Solismaa, Milla; Kortet, Raine; Kuusela, Jussi; Oksanen, Antti

    2009-01-01

    Background Recent studies have revealed expansion by an array of Filarioid nematodes' into the northern boreal region of Finland. The vector-borne nematode, Setaria tundra, caused a serious disease outbreak in the Finnish reindeer population in 2003–05. The main aim of this study was to understand the outbreak dynamics and the rapid expansion of S. tundra in the sub arctic. We describe the vectors of S. tundra, and its development in vectors, for the first time. Finally we discuss the results in the context of the host-parasite ecology of S. tundra in Finland Results Development of S. tundra to the infective stage occurs in mosquitoes, (genera Aedes and Anopheles). We consider Aedes spp. the most important vectors. The prevalence of S. tundra naturally infected mosquitoes from Finland varied from 0.5 to 2.5%. The rate of development in mosquitoes was temperature-dependent. Infective larvae were present approximately 14 days after a blood meal in mosquitoes maintained at room temperature (mean 21 C), but did not develop in mosquitoes maintained outside for 22 days at a mean temperature of 14.1 C. The third-stage (infective) larvae were elongated (mean length 1411 μm (SD 207), and width 28 μm (SD 2)). The anterior end was blunt, and bore two liplike structures, the posterior end slight tapering with a prominent terminal papilla. Infective larvae were distributed anteriorly in the insect's body, the highest abundance being 70 larvae in one mosquito. A questionnaire survey revealed that the peak activity of Culicidae in the reindeer herding areas of Finland was from the middle of June to the end of July and that warm summer weather was associated with reindeer flocking behaviour on mosquito-rich wetlands. Conclusion In the present work, S. tundra vectors and larval development were identified and described for the first time. Aedes spp. mosquitoes likely serve as the most important and competent vectors for S. tundra in Finland. Warm summers apparently promote

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

    PubMed

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

    2016-08-01

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

  14. Transcriptome analysis of the adult rumen fluke Paramphistomum cervi following next generation sequencing.

    PubMed

    Choudhary, Vijayata; Garg, Sweta; Chourasia, Reetika; Hasnani, J J; Patel, P V; Shah, Tejas M; Bhatt, Vaibhav D; Mohapatra, Amitbikram; Blake, Damer P; Joshi, Chaitanya G

    2015-10-01

    Rumen flukes are parasitic trematodes (Platyhelminthes: Digenea) of major socioeconomic importance in many countries. Key representatives, such as Paramphistomum cervi, can cause "Rumen fluke disease" or paramphistomosis and undermine economic animal productivity and welfare. P. cervi is primarily a problem in sheep, goat and buffalo production as a consequence of reduced weight gain and milk production, clinical disease or death. Recent technological advances in genomics and bioinformatics now provide unique opportunities for the identification and pre-validation of drug targets and vaccines through improved understanding of the biology of pathogens such as P. cervi and their relationship with their hosts at the molecular level. Here, we report next generation transcriptome sequencing analysis for P. cervi. RNAseq libraries were generated from RNA extracted from 15 adult P. cervi parasites sampled from each of three different host species (sheep, goat and buffalo) and a reference transcriptome was generated by assembly of all Ion Torrent PGM sequencing data. Raw reads (7,433,721 in total) were initially filtered for host nucleotide contamination and ribosomal RNAs and the remaining reads were assembled into 43,753 high confidence transcript contigs. In excess of 50% of the assembled transcripts were annotated with domain- or protein sequence similarity derived functional information. The reference adult P. cervi transcriptome will serve as a basis for future work on the biology of this important parasite. Using the widely investigated trematode virulence factor and vaccine candidate Cathepsin L as an example, the epitope GPISIAINA was found to be conserved in P. cervi isolated from three different host species supporting its candidacy for vaccine development and illustrating the utility of the adult P. cervi transcriptome. PMID:26049095

  15. Morphological and histological identification of Paramphistomum cervi (Trematoda: Paramiphistoma) in the rumen of infected sheep

    PubMed Central

    Chaoudhary, Vijayata; Hasnani, J. J.; Khyalia, Mukesh K.; Pandey, Sunanda; Chauhan, Vandip D.; Pandya, Suchit S.; Patel, P. V.

    2015-01-01

    Aim: This study was undertaken to identify Paramphistomum cervi on the basis of its morphology and histology to be the common cause of paramphistomosis in infected sheep and its differentiation from other similar Paramphistomes in Gujarat. Materials and Methods: Adult rumen flukes were recovered from the rumen of naturally infected sheep slaughtered in various abattoirs in Gujarat. Some adult flukes were flattened and stained in Borax carmine, and some were sectioned in the median sagittal plane and histological slides of the flukes were prepared for detailed morphological and histological studies. Result: Microscopic pictures of the parasite used in identification define the similarity in the morphology and histology of the anterior sucker, pharynx, esophagus, genital atrium, posterior sucker (acetabulum) and testes to the P. cervi. Conclusion: It can be concluded that the most common species found in sheep infected with Paramphistomosis is P. cervi on the basis of its histo-morphological appearance in Gujarat. PMID:27047009

  16. [Investigations on the biology of nematodes Elaphostrongylus cervi and epizootiology of elaphostrongylosis].

    PubMed

    Kuligowska, Izabela

    2009-01-01

    Elaphostrongylus cervi is a parasite of the family Protostrongylidae, occurring in cervids in Eurasia. This nematode has hitherto been recorded in some woodland areas in Poland. The current distribution of E. cervi in Poland was studied in the frames of the presently reported thesis. The above-mentioned nematode was found in deer in eight additional voivodeships, and in all thirteen forest management units examined. The prevalence values ranged from 66.7% to 100%. The above facts justify the statement that that E. cervi is a common parasite species in Poland. The dynamics of the larval shedding (L I) by deer was monitored and it turned out that there were two peaks--the first in February and the second in December. The identity of the intermediate hosts--terrestrial snails--has been established, as well as the prevalence and the infection intensity of their natural infections. The intermediate hosts of E. cervi are Succinea putris, Bradybena fruticum, Perforatella bidens, and Zonitoides nitidus. It was determined that the prevalence of snails, S. putris, infected with E. cervi larvae maintained a constant level from June to August and it decreased in September and October. Snails, B. fruticum, showed the highest prevalence in July--and it decreased in subsequent months. In the case of P. bidens the prevalence of E. cervi infection was the lowest in August, and than it increased, to reach the highest value in October. The prevalence of spontaneous infections of different snail species ranged from 7.6% to 20.6%. For the first time the highest prevalence of spontaneous infection was found in P. bidens. Till now the most infected species of snail has always been S. putris. The highest intensity of infection--242 larvae--was found in B. fruticum, and little lower--202 in S. putris. In two other species the intensity ranged from 1 to 23 larvae. The most significant role in spreading of E. cervi in the Białowieza Forest is performed by S. putris and B. fruticum, because

  17. The parasitic fauna of the European bison (Bison bonasus) (Linnaeus, 1758) and their impact on the conservation. Part 1. The summarising list of parasites noted.

    PubMed

    Karbowiak, Grzegorz; Demiaszkiewicz, Aleksander W; Pyziel, Anna M; Wita, Irena; Moskwa, Bożena; Werszko, Joanna; Bień, Justyna; Goździk, Katarzyna; Lachowicz, Jacek; Cabaj, Władysław

    2014-09-01

    During the current century, 88 species of parasites have been recorded in Bison bonasus. These are 22 species of protozoa (Trypanosoma wrublewskii, T. theileri, Giardia sp., Sarcocystis cruzi, S. hirsuta, S. hominis, S. fusiformis, Neospora caninum, Toxoplasma gondii, Cryptosporidium sp., Eimeria cylindrica, E. subspherica, E. bovis, E. zuernii, E. canadensis, E. ellipsoidalis, E. alabamensis, E. bukidnonensis, E. auburnensis, E. pellita, E. brasiliensis, Babesia divergens), 4 trematodes species (Dicrocoelium dendriticum, Fasciola hepatica, Parafasciolopsis fasciolaemorpha, Paramphistomum cervi), 4 cestodes species (Taenia hydatigena larvae, Moniezia benedeni, M. expansa, Moniezia sp.), 43 nematodes species (Bunostomum trigonocephalum, B. phlebotomum, Chabertia ovina, Oesophagostomum radiatum, O. venulosum, Dictyocaulus filaria, D.viviparus, Nematodirella alcidis, Nematodirus europaeus, N. helvetianus, N. roscidus, N. filicollis, N. spathiger, Cooperia oncophora, C. pectinata, C. punctata, C. surnabada, Haemonchus contortus, Mazamastrongylus dagestanicus, Ostertagia lyrata, O. ostertagi, O. antipini, O. leptospicularis, O. kolchida, O. circumcincta, O. trifurcata, Spiculopteragia boehmi, S. mathevossiani, S. asymmetrica, Trichostrongylus axei, T. askivali, T. capricola, T. vitrinus, Ashworthius sidemi, Onchocerca lienalis, O. gutturosa, Setaria labiatopapillosa, Gongylonema pulchrum, Thelazia gulosa, T. skrjabini, T. rhodesi, Aonchotheca bilobata, Trichuris ovis), 7 mites (Demodex bisonianus, D. bovis, Demodex sp., Chorioptes bovis, Psoroptes equi, P. ovis, Sarcoptes scabiei), 4 Ixodidae ticks (Ixodes ricinus, I. persulcatus, I. hexagonus, Dermacentor reticulatus), 1 Mallophaga species (Bisonicola sedecimdecembrii), 1 Anoplura (Haematopinus eurysternus), and 2 Hippoboscidae flies (Lipoptena cervi, Melophagus ovinus). There are few monoxenous parasites, many typical for cattle and many newly acquired from Cervidae. PMID:25119348

  18. Setaria digitata in advancing our knowledge of human lymphatic filariasis.

    PubMed

    Perumal, A N I; Gunawardene, Y I N S; Dassanayake, R S

    2016-03-01

    Setaria digitata is a filarial parasite that causes fatal cerebrospinal nematodiasis in goats, sheep and horses, resulting in substantial economic losses in animal husbandry in the tropics. Due to its close resemblance to Wuchereria bancrofti, this nematode is also frequently used as a model organism to study human lymphatic filariasis. This review highlights numerous insights into the morphological, histological, biochemical, immunological and genetic aspects of S. digitata that have broadened our understanding towards the control and eradication of filarial diseases. PMID:25924635

  19. Review of Cervi Cornu Parvum Pharmacopuncture in Korean Medicine

    PubMed Central

    Lee, Dong-Jin; Hwangbo, Min; Kwon, Kang; Seo, Hyung-Sik

    2013-01-01

    Objective: The endpoint of this review is to investigate existing studies of Cervi cornu parvum(CCP) pharmacopuncture within Korean medicine journals in order to present a better research method in the future. Methods: We searched all the papers through six Korean electrical databases that included the title of " Cervi cornu parvum pharmacopuncture" or " Cervi cornu parvum aqua-acupuncture". Articles that had been published until December 2012 were largely divided into experimental studies and clinical studies. Results: Fifty-three (53) experimental studies and six clinical studies were found. The number of published articles has been constantly increasing. Many of the experimental studies demonstrated anti-inflammatory effects for arthritis, and most of the clinical studies dealt with musculoskeletal problems. Conclusion: Various therapeutically significant effects of the CCP pharmacopuncture have been found through this review; however, more systematic clinical studies on the CCP pharmacopuncture seem to be necessary to substantially support its clinical effects. PMID:25780662

  20. Paramphistomum cervi: the in vitro effect of plumbagin on motility, survival and tegument structure.

    PubMed

    Saowakon, Naruwan; Lorsuwannarat, Natcha; Changklungmoa, Narin; Wanichanon, Chaitip; Sobhon, Prasert

    2013-02-01

    Paramphistomiasis causes enteritis and anemia in livestocks and result in substantial production and economic losses. It is considered a neglected tropical disease, with no effective trematodicidal compound for treatment. Plumbagin (PB), a compound founds to be rich in the roots of Plumbago indica, is a naphthoquinone derivatives which can induce oxidative stress in parasites. In this study we have evaluated the anthelmintic activity of PB against adult Paramphistomum cervi by incubating the parasites in M-199 medium containing 0.1, 1.0, 10 and 100 μg/ml of the PB, and albendazole (ABZ) at the concentration of 100 μg/ml as the positive control, for 3, 6, 12 and 24 h, using relative motility (RM) assay and observed by scanning electron microscopy (SEM). After 12 h exposure with 100 μg/ml ABZ, flukes showed decreased contraction and motility. At 24 h incubation they showed only active movement of some part of the body. The PB-treated flukes at all concentrations showed rapid decrease of motility at 3 h incubation. In 0.1, 1.0 and 10 μg/ml of PB, the RM values were decreased sharply from 3 to 12 h, and then they were killed since 12 h in the incubation with 10 μg/ml of PB. The highest parasite mortality was found as early as 3h when they were incubated with 100 μg/ml of PB. The morphological changes on the tegumental surface were similar in both flukes treated with ABZ and PB, which sequentially comprised of swelling, followed by blebbings that later ruptured, leading to the erosion and desquamation of the tegument syncytium. As the result, lesions were formed which exposed the basal lamina. The damage appeared more severe on the ventral than the dorsal surface, and earlier on the anterior part and lateral margins of middle third when compared to the posterior part of the parasites's bodies. The severity and rapidity of the damages were enhanced with increasing concentration of PB, which showed stronger activity than ABZ. Hence, PB has a potential to be an

  1. Parasites

    MedlinePlus

    ... CME and CNE for clinicians... Parasitic Disease and Malaria Strategic Priorities: 2015—2020... Cyclosporiasis: Most U.S. cases ... R S T U V W X Y Z Malaria An ancient disease that affects millions of people ...

  2. Acute impacts of the deer ked (Lipoptena cervi) infestation on reindeer (Rangifer tarandus tarandus) behaviour.

    PubMed

    Kynkäänniemi, Sanna-Mari; Kettu, Maria; Kortet, Raine; Härkönen, Laura; Kaitala, Arja; Paakkonen, Tommi; Mustonen, Anne-Mari; Nieminen, Petteri; Härkönen, Sauli; Ylönen, Hannu; Laaksonen, Sauli

    2014-04-01

    Blood-sucking ectoparasites have often a strong impact on the behaviour of their hosts. The annual insect harassment of reindeer (Rangifer tarandus tarandus) has increased in the southern part of the Finnish reindeer herding area because of the recent invasion of a blood-feeding ectoparasitic louse-fly, the deer ked (Lipoptena cervi). We studied the impact of the deer ked on the behaviour of reindeer. Twelve reindeer were infested with a total of 300 keds/reindeer on six occasions in a 5-week period during the deer ked flight season in autumn, while six non-infested reindeer were used as controls. Behavioural patterns indicating potential stress were monitored by visual observation from August to December. The infested reindeer displayed more incidences of restless behaviour than the controls. Shaking and scratching were the most common forms of restless behaviour after infestation of deer keds. Increased grooming was also observed after the transplantation and also later, 1 month after the infestation. Based on the results, the deer ked infestation can cause acute behavioural disturbance in reindeer and, thus, could pose a potential threat to reindeer welfare. Antiparasitic treatment with, e.g. ivermectin, may increase the welfare of parasitized reindeer by reducing deer keds. If the deer ked infestation intensity on the reindeer herding area increases and restless behaviour of reindeer becomes more common, the present results can help in further evaluation of the duration and magnitude of behavioural changes. PMID:24562815

  3. 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

  4. Reference genome sequence of the model plant Setaria

    SciTech Connect

    Bennetzen, Jeffrey L; Schmutz, Jeremy; Wang, Hao; Percifield, Ryan; Hawkins, Jennifer; Pontaroli, Ana C.; Estep, Matt; Feng, Liang; Vaughn, Justin N; Grimwood, Jane; Jenkins, Jerry; Barry, Kerrie; Lindquist, Erika; Hellsten, Uffe; Deshpande, Shweta; Wang, Xuewen; Wu, Xiaomei; Mitros, Therese; Triplett, Jimmy; Yang, Xiaohan; Ye, Chuyu; Mauro-Herrera, Margarita; Wang, Lin; Li, Pinghua; Sharma, Manoj; Sharma, Rita; Ronald, Pamela; Panaud, Olivier; Kellogg, Elizabeth A.; Brutnell, Thomas P.; Doust, Andrew N.; Tuskan, Gerald A; Rokhsar, Daniel; Devos, Katrien M

    2012-01-01

    We generated a high-quality reference genome sequence for foxtail millet (Setaria italica). The ~400-Mb assembly covers ~80% of the genome and >95% of the gene space. The assembly was anchored to a 992-locus genetic map and was annotated by comparison with >1.3 million expressed sequence tag reads. We produced more than 580 million RNA-Seq reads to facilitate expression analyses. We also sequenced Setaria viridis, the ancestral wild relative of S. italica, and identified regions of differential single-nucleotide polymorphism density, distribution of transposable elements, small RNA content, chromosomal rearrangement and segregation distortion. The genus Setaria includes natural and cultivated species that demonstrate a wide capacity for adaptation. The genetic basis of this adaptation was investigated by comparing five sequenced grass genomes. We also used the diploid Setaria genome to evaluate the ongoing genome assembly of a related polyploid, switchgrass (Panicum virgatum).

  5. Reference genome sequence of the model plant Setaria

    SciTech Connect

    Bennetzen, Jeffrey L; Yang, Xiaohan; Ye, Chuyu; Tuskan, Gerald A

    2012-01-01

    We generated a high-quality reference genome sequence for foxtail millet (Setaria italica). The {approx}400-Mb assembly covers {approx}80% of the genome and >95% of the gene space. The assembly was anchored to a 992-locus genetic map and was annotated by comparison with >1.3 million expressed sequence tag reads. We produced more than 580 million RNA-Seq reads to facilitate expression analyses. We also sequenced Setaria viridis, the ancestral wild relative of S. italica, and identified regions of differential single-nucleotide polymorphism density, distribution of transposable elements, small RNA content, chromosomal rearrangement and segregation distortion. The genus Setaria includes natural and cultivated species that demonstrate a wide capacity for adaptation. The genetic basis of this adaptation was investigated by comparing five sequenced grass genomes. We also used the diploid Setaria genome to evaluate the ongoing genome assembly of a related polyploid, switchgrass (Panicum virgatum).

  6. The Mitochondrial Genome of Paramphistomum cervi (Digenea), the First Representative for the Family Paramphistomidae

    PubMed Central

    Lou, Zhong-Zi; Li, Li; Blair, David; Yin, Hong; Cai, Jin-Zhong; Dai, Xue-Ling; Lei, Meng-Tong; Zhu, Xing-Quan; Cai, Xue-Peng; Jia, Wan-Zhong

    2013-01-01

    We determined the complete mitochondrial DNA (mtDNA) sequence of a fluke, Paramphistomum cervi (Digenea: Paramphistomidae). This genome (14,014 bp) is slightly larger than that of Clonorchis sinensis (13,875 bp), but smaller than those of other digenean species. The mt genome of P. cervi contains 12 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 2 non-coding regions (NCRs), a complement consistent with those of other digeneans. The arrangement of protein-coding and ribosomal RNA genes in the P. cervi mitochondrial genome is identical to that of other digeneans except for a group of Schistosoma species that exhibit a derived arrangement. The positions of some transfer RNA genes differ. Bayesian phylogenetic analyses, based on concatenated nucleotide sequences and amino-acid sequences of the 12 protein-coding genes, placed P. cervi within the Order Plagiorchiida, but relationships depicted within that order were not quite as expected from previous studies. The complete mtDNA sequence of P. cervi provides important genetic markers for diagnostics, ecological and evolutionary studies of digeneans. PMID:23990943

  7. Phytolith Analysis for Differentiating between Foxtail Millet (Setaria italica) and Green Foxtail (Setaria viridis)

    PubMed Central

    Zhang, Jianping; Lu, Houyuan; Wu, Naiqin; Yang, Xiaoyan; Diao, Xianmin

    2011-01-01

    Foxtail millet (Setaria italica) is one of the oldest domesticated cereal crops in Eurasia, but identifying foxtail millets, especially in charred grains, and differentiating it from its wild ancestor, green foxtail (Setaria viridis), in the archaeobotanical remains, is still problematic. Phytolithic analysis provides a meaningful method for identifying this important crop. In this paper, the silicon structure patterns in the glumes, lemmas, and paleas from inflorescence bracts in 16 modern plants of foxtail millet and green foxtail from China and Europe are examined using light microscopy with phase-contrast and a microscopic interferometer. Our research shows that the silicon structure of ΩIII from upper lemmas and paleas in foxtail millet and green foxtail can be correspondingly divided into two groups. The size of ΩIII type phytolith of foxtail millet is bigger than that from green foxtail. Discriminant function analysis reveals that 78.4% of data on foxtail millet and 76.9% of data on green foxtail are correctly classified. This means certain morphotypes of phytoliths are relatively reliable tools for distinguishing foxtail millet from green foxtail. Our results also revealed that the husk phytolith morphologies of foxtail millets from China and Eastern Europe are markedly different from those from Western Europe. Our research gives a meaningful method of separating foxtail millet and green foxtail. The implications of these findings for understanding the history of foxtail millet domestication and cultivation in ancient civilizations are significant. PMID:21573069

  8. [Stone age deerfly (Lipoptena cervi) found with a mummy in a glacier].

    PubMed

    Gothe, R; Schöl, H

    1996-12-01

    In hair samples from the accompanying equipment of a human mummy preserved in glacial ice in South Tyrol for more than 5000 years, numerous remains of insects were found. These fragments corresponded in form, size and structural organization to the features of the deer ked, Lipoptena cervi. Considering the biology and ecology of L. cervi with regard to the finding place of the mummy at an altitude of 3210 m above sea level in a glacier it is concluded that the deer keds invaded the equipment before and not after the death of the Stone Age man. PMID:9139418

  9. Spike-dip transformation of Setaria viridis.

    PubMed

    Saha, Prasenjit; Blumwald, Eduardo

    2016-04-01

    Traditional method of Agrobacterium-mediated transformation through the generation of tissue culture had limited success for Setaria viridis, an emerging C4 monocot model. Here we present an efficient in planta method for Agrobacterium-mediated genetic transformation of S. viridis using spike dip. Pre-anthesis developing spikes were dipped into a solution of Agrobacterium tumefaciens strain AGL1 harboring the β-glucuronidase (GUS) reporter gene driven by the cauliflower mosaic virus 35S (CaMV35S) promoter to standardize and optimize conditions for transient as well as stable transformations. A transformation efficiency of 0.8 ± 0.1% was obtained after dipping of 5-day-old S3 spikes for 20 min in Agrobacterium cultures containing S. viridis spike-dip medium supplemented with 0.025% Silwet L-77 and 200 μm acetosyringone. Reproducibility of this method was demonstrated by generating stable transgenic lines expressing β-glucuronidase plus (GUSplus), green fluorescent protein (GFP) and Discosoma sp. red fluorescent protein (DsRed) reporter genes driven by either CaMV35S or intron-interrupted maize ubiquitin (Ubi) promoters from three S. viridis genotypes. Expression of these reporter genes in transient assays as well as in T1 stable transformed plants was monitored using histochemical, fluorometric GUS activity and fluorescence microscopy. Molecular analysis of transgenic lines revealed stable integration of transgenes into the genome, and inherited transgenes expressed in the subsequent generations. This approach provides opportunities for the high-throughput transformation and potentially facilitates translational research in a monocot model plant. PMID:26932666

  10. Population genetics of Setaria viridis, a new model system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An extensive survey of the standing genetic variation in natural populations is among the priority steps in developing a species into a model system. In recent years, green foxtail (Setaria viridis), along with its domesticated form foxtail millet (S. italica), has rapidly become a promising new mod...

  11. Sex, age, spleen size, and kidney fat of red deer relative to infection intensities of the lungworm Elaphostrongylus cervi

    NASA Astrophysics Data System (ADS)

    Vicente, J.; Pérez-Rodríguez, L.; Gortazar, C.

    2007-07-01

    We analyzed the relationships among spleen size, body condition (measured as kidney fat), and larval counts of the nematode Elaphostrongylus cervi in red deer ( Cervus elaphus). The aim was to investigate the interaction between host body condition and intensity of infection with parasites. As red deer are highly polygynous, we also tested whether these relationships varied with sex and age of the hosts. Kidney fat and spleen size were positively correlated in subadults (2-3 years old) and adults (>3 years old), but not in calves (<1 year old) or yearlings (1-2 years old). Spleen size was negatively associated with nematode load in subadult females and in adult males. These two age classes are potentially the most nutritionally stressed, as subadult hinds are still growing and often engaging in rearing their first calf, and adult stags were sampled just after the rut, which is recognized as a substantial energy drain in this age-sex class, as they compete to hold females during the mating season. Body condition related negatively to parasite count only in adult males. In the context of red deer life history, these findings suggest that spleen size is dependent on body condition and that it could be affected by variation in resource partitioning among immune defense, growth, and reproductive effort in red deer. For the first time in a wild mammal, the spleen mass is shown to be positively related to body condition and negatively related to parasite infection. We conclude that elucidating whether spleen mass reflects immune defense investment or a measure of general body condition should contribute to understanding topical issues in mammal ecology.

  12. Ribosomal DNA in diploid and polyploid Setaria (Poaceae) species: number and distribution

    PubMed Central

    Nani, Thaís Furtado; Cenzi, Gisele; Pereira, Daniele Lais; Davide, Lisete Chamma; Techio, Vânia Helena

    2015-01-01

    Abstract Setaria Beauvois, 1812 is a genus of economically important forage species, including Setaria italica (Linnaeus, 1753) Beauvois, 1812 and Setaria viridis (Linnaeus, 1753) Beauvois, 1812, closely related species and considered as model systems for studies of C4 plants. However, complications and uncertainties related to taxonomy of other species of the genus are frequent due to the existence of numerous synonyms for the same species or multiple species with the same name, and overlapping of morphological characteristics. Cytogenetic studies in Setaria can be useful for taxonomic and evolutionary studies as well as for applications in breeding. Thus, this study is aimed at locating 45S and 5S rDNA sites through fluorescent in situ hybridization (FISH) in Setaria italica, Setaria viridis and Setaria sphacelata (Schumacher, 1827) Stapf, Hubbard, Moss, 1929 cultivars (cvs.) Narok and Nandi. Setaria italica and Setaria viridis have 18 chromosomes with karyotype formulas 6m + 3sm and 9m, respectively. The location of 45S and 5S rDNA for these species was in different chromosome pairs among the evaluated species. Setaria viridis presented a more symmetrical karyotype, strengthening the ancestral relationship with Setaria italica. Setaria sphacelata cvs. Narok and Nandi have 36 chromosomes, and karyotype formulas 11m+7sm and 16m+2sm, respectively. The 45S rDNA signals for both cultivars were also observed in distinct chromosome pairs; however chromosomes bearing 5S rDNA are conserved. Karyotypic variations found among the studied species are evidence of chromosomal rearrangements. PMID:26753080

  13. Setaria digitata microfilaraemia in Mastomys coucha: an animal model for chemotherapeutic and immunobiological studies.

    PubMed

    Mukhopadhyay, S; Dash, A P; Ravindran, B

    1996-10-01

    Intraperitoneal implantation of adult gravid females of the bovine filarial parasite, Setaria digitata in Mastomys coucha was found to induce microfilaraemia lasting for about 125 days. The microfilariae (mf) could be detected as early as 4 days post-implantation (p.i.) and peak levels of about 30 mf in 20 microliters of blood were observed by 21 days. A significant positive correlation was found between mf density and the body weight of recipients pre-implantation. The implanted adult worms were generally viable only for less than 1 week. Implantation resulted in a significant decrease in total leucocytes and erythrocytes, induction of eosinophilia, splenomegaly and anti-erythrocyte autoantibodies. The microfilariae in circulation developed into 3rd-stage infective larvae (L3) when fed onto Aedes aegypti (refm, Liverpool strain). The mf in circulation were found to be eliminated by oral administration of diethylcarbamazine citrate, indicating the usefulness of this model for screening potential anti-microfilarial drugs. During the microfilaraemic phase, priming with tetanus toxoid (TT) resulted in significantly decreased production of anti-toxin levels indicating a state of generalized immunosuppression. Induction of antibodies to various fractionated antigenic components of adult parasites could be demonstrated by enzyme immunoassay (EIA) in M. coucha implanted with live or cold-stunned adult worms. The S. digitata-M. coucha model thus is found amenable to perform chemotherapeutic and immunobiological investigations in experimental filariasis. PMID:8873474

  14. Bartonella Infections in Deer Keds (Lipoptena cervi) and Moose (Alces alces) in Norway

    PubMed Central

    Duodu, Samuel; Madslien, Knut; Hjelm, Eva; Molin, Ylva; Paziewska-Harris, Anna; Harris, Philip D.; Colquhoun, Duncan J.

    2013-01-01

    Infections with Bartonella spp. have been recognized as emerging zoonotic diseases in humans. Large knowledge gaps exist, however, relating to reservoirs, vectors, and transmission of these bacteria. We describe identification by culture, PCR, and housekeeping gene sequencing of Bartonella spp. in fed, wingless deer keds (Lipoptena cervi), deer ked pupae, and blood samples collected from moose, Alces alces, sampled within the deer ked distribution range in Norway. Direct sequencing from moose blood sampled in a deer ked-free area also indicated Bartonella infection but at a much lower prevalence. The sequencing data suggested the presence of mixed infections involving two species of Bartonella within the deer ked range, while moose outside the range appeared to be infected with a single species. Bartonella were not detected or cultured from unfed winged deer keds. The results may indicate that long-term bacteremia in the moose represents a reservoir of infection and that L. cervi acts as a vector for the spread of infection of Bartonella spp. Further research is needed to evaluate the role of L. cervi in the transmission of Bartonella to animals and humans and the possible pathogenicity of these bacteria for humans and animals. PMID:23104416

  15. Experimental infection of the deer ked (Lipoptena cervi) has no negative effects on the physiology of the captive reindeer (Rangifer tarandus tarandus).

    PubMed

    Paakkonen, Tommi; Mustonen, Anne-Mari; Käkelä, Reijo; Kiljander, Teemu; Kynkäänniemi, Sanna-Mari; Laaksonen, Sauli; Solismaa, Milla; Aho, Jari; Kortet, Raine; Puukka, Katri; Saarela, Seppo; Härkönen, Laura; Kaitala, Arja; Ylönen, Hannu; Nieminen, Petteri

    2011-06-30

    The deer ked (Lipoptena cervi) is a haematophagous parasitic fly of cervids that spread to Finland in the early 1960's. Presently its northern distribution limit lies at approximately 65°N and it is gradually spreading northwards. In Finland the principal host species has been the moose (Alces alces), but the deer ked is about to establish contact with another potential host, the semi-domesticated reindeer (Rangifer tarandus tarandus) causing possible threats to reindeer health and management. The aim of this study was to investigate if the deer ked would have an influence on the welfare of the reindeer. Eighteen adult reindeer were divided into three experimental groups: the control group and two infected groups with 300 deer keds per reindeer introduced in August-September. One of the infected groups was treated with subcutaneous ivermectin in November. To gather comprehensive data on potential health hazards caused by the deer ked a wide array of physiological variables was measured during and at the end of the experiment in December. The keds caused no clear changes in the complete blood count, plasma clinical chemistry, amino acids, endocrinology, energy stores, enzyme activities or tissue fatty acid profiles of the host. The haematological, clinical chemical and endocrinological values displayed changes that could be related to the seasonal physiological adaptations of the species. In conclusion, at the duration and intensity of infection that were employed, the effects of the deer ked on the measured physiological variables of the reindeer were insignificant. PMID:21439734

  16. Biochemical studies on glutathione S-transferase from the bovine filarial worm Setaria digitata.

    PubMed

    Srinivasan, Lakshmy; Mathew, Nisha; Karunan, Twinkle; Muthuswamy, Kalyanasundaram

    2011-07-01

    Setaria digitata is a filarial worm of the cattle used as a model system for antifilarial drug screening, due to its similarity to the human filarial parasites Wuchereria bancrofti and Brugia malayi. Since filarial glutathione S-transferase (GST) is a good biochemical target for antifilarial drug development, a study has been undertaken for the biochemical characterization of GST from S. digitata. Cytosolic fraction was separated from the crude S.digitata worm homogenate by ultracentrifugation at 100,000 g and subjected to ammonium sulfate precipitation followed by affinity chromatography using GSH-agarose column. The kinetic parameters K (m) and V (max) values with respect to GSH were 0.45 mM and 0.105 μmol min(-1) mL(-1) respectively. With respect to 1-chloro-2,4-dinitrobenzene, the K (m) and V (max) values were 1.21 and 0.117 μmol min(-1) mL(-1) respectively. The effect of temperature and pH on GST enzyme activity was studied. The protein retained its enzyme activity between 0°C and 40°C, beyond which it showed a decreasing tendency, and at 80°C, the activity was lost completely. The enzyme activity was varying with change in pH, and the maximum GST activity was observed at pH 7.5. Gel filtration chromatographic studies indicated that the protein has a native molecular mass of about 54 kDa. The single band of GST subunit appeared in sodium dodecyl sulfate polyacrylamide gel electrophoresis was found to have molecular mass of ∼27 kDa. This shows that cytosolic S. digitata GST protein is homodimeric in nature. PMID:21207063

  17. Molecular detection of Dirofilaria immitis, Dirofilaria repens and Setaria tundra in mosquitoes from Germany

    PubMed Central

    2014-01-01

    Background As a result of globalization and climate change, Dirofilaria immitis and Dirofilaria repens, the causative agents of dirofilariosis in Europe, continue to spread from endemic areas in the Mediterranean to northern and northeastern regions of Europe where autochthonous cases of dirofilarial infections have increasingly been observed in dogs and humans. Whilst D. repens was recently reported from mosquitoes in putatively non-endemic areas, D. immitis has never been demonstrated in mosquitoes from Europe outside the Mediterranean. Methods From 2011 to 2013, mosquitoes collected within the framework of a German national mosquito monitoring programme were screened for filarial nematodes using a newly designed filarioid-specific real-time PCR assay. Positive samples were further processed by conventional PCR amplification of the cytochrome c oxidase subunit I (COI) gene, amplicons were sequenced and sequences blasted against GenBank. Results Approximately 17,000 female mosquitoes were subjected to filarial screening. Out of 955 pools examined, nine tested positive for filariae. Two of the COI sequences indicated D. immitis, one D. repens and four Setaria tundra. Two sequences could not be assigned to a known species due to a lack of similar GenBank entries. Whilst D. immitis and the unknown parasites were detected in Culex pipiens/torrentium, D. repens was found in a single Anopheles daciae and all S. tundra were demonstrated in Aedes vexans. All positive mosquitoes were collected between mid-June and early September. Conclusion The finding of dirofilariae in German mosquitoes implies the possibility of a local natural transmission cycle. While the routes of introduction to Germany and the origin of the filariae cannot be determined retrospectively, potential culicid vectors and reservoir hosts must prospectively be identified and awareness among physicians, veterinarians and public health personnel be created. The health impact of S. tundra on the indigenous

  18. Population genetics of Setaria viridis, a new model system.

    PubMed

    Huang, Pu; Feldman, Maximilian; Schroder, Stephan; Bahri, Bochra A; Diao, Xianmin; Zhi, Hui; Estep, Matt; Baxter, Ivan; Devos, Katrien M; Kellogg, Elizabeth A

    2014-10-01

    An extensive survey of the standing genetic variation in natural populations is among the priority steps in developing a species into a model system. In recent years, green foxtail (Setaria viridis), along with its domesticated form foxtail millet (S. italica), has rapidly become a promising new model system for C4 grasses and bioenergy crops, due to its rapid life cycle, large amount of seed production and small diploid genome, among other characters. However, remarkably little is known about the genetic diversity in natural populations of this species. In this study, we survey the genetic diversity of a worldwide sample of more than 200 S. viridis accessions, using the genotyping-by-sequencing technique. Two distinct genetic groups in S. viridis and a third group resembling S. italica were identified, with considerable admixture among the three groups. We find the genetic variation of North American S. viridis correlates with both geography and climate and is representative of the total genetic diversity in this species. This pattern may reflect several introduction/dispersal events of S. viridis into North America. We also modelled demographic history and show signal of recent population decline in one subgroup. Finally, we show linkage disequilibrium decay is rapid (<45 kb) in our total sample and slow in genetic subgroups. These results together provide an in-depth understanding of the pattern of genetic diversity of this new model species on a broad geographic scale. They also provide key guidelines for on-going and future work including germplasm preservation, local adaptation, crossing designs and genomewide association studies. PMID:25185718

  19. Life stage-related differences in fatty acid composition of an obligate ectoparasite, the deer ked (Lipoptena cervi)-influence of blood meals and gender.

    PubMed

    Mustonen, Anne-Mari; Käkelä, Reijo; Paakkonen, Tommi; Nieminen, Petteri

    2015-01-01

    Metamorphosis and diet often influence fatty acid (FA) signatures (FAS) of insects. We investigated FAS in a hematophagous ectoparasite, the deer ked (Lipoptena cervi). Deer keds shed their wings upon attachment on the host and, thus, the FAS of an individual blood-fed imago/pupa in the fur of its host can be traced back to the blood FA profile of a single moose (Alces alces). Host blood and different life stages of deer keds were investigated for FA by gas chromatography. The FAS of life stages resembled each other more closely than the diet. Blood meals modified the FAS of both sexes but the FAS of the blood-fed females were closer to those of the prepupae/pupae. The parasitizing males had higher proportions of major saturated FA (SFA) and polyunsaturated FA (PUFA) than the females, which contained more monounsaturated FA (MUFA) with higher ratios of n-3/n-6 PUFA and unsaturated FA (UFA)/SFA. The proportions of 16:1n-7 were <1% in the blood but 18% (males) and 29% (females) in the blood-fed keds. Allocation of lipids to offspring by the females and possible accumulation of PUFA in male reproductive organs may have induced these sex-related differences. MUFA percentages and UFA/SFA ratios increased while SFA and many PUFA decreased from the reproducing females to the pupae. The diapausing pupae displayed lowered n-3/n-6 PUFA ratios and could have mobilized 16:0 and 18:3n-3 for the most fundamental metabolic processes. In conclusion, FAS are modified through the life stages of the deer ked possibly due to their different FA requirements. PMID:25223709

  20. The Nutritive Value of Dying Maize and Setaria Faberi Roots for Western Corn Rootworm Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The timing that senescing root tissues of Setaria faberi R.A.W. Herrm. and maize, Zea mays L., no longer support growth and development of neonate and 2nd instar western corn rootworm, Diabrotica virgifera virgifera LeConte, larvae was evaluated under greenhouse conditions. Three separate experimen...

  1. Setaria viridis floral-dip: A simple and rapid Agrobacterium-medicated transformation method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Setaria viridis was recently described as a new monocotyledonous model species for C4 photosynthesis research and genetic transformation. It has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements) that make it suitable for use as a model plan...

  2. Factors affecting deer ked (Lipoptena cervi) prevalence and infestation intensity in moose (Alces alces) in Norway

    PubMed Central

    2012-01-01

    Background The deer ked (Lipoptena cervi), a hematophagous ectoparasite of Cervids, is currently spreading in Scandinavia. In Norway, keds are now invading the south-eastern part of the country and the abundant and widely distributed moose (Alces alces) is the definitive host. However, key factors for ked abundance are poorly elucidated. The objectives of our study were to (i) determine deer ked infestation prevalence and intensity on moose and (ii) evaluate if habitat characteristics and moose population density are determinants of deer ked abundance on moose. Methods In order to identify key factors for deer ked abundance, a total of 350 skin samples from the neck of hunted moose were examined and deer keds counted. Infestation intensity was analyzed in relation to moose age and sex, moose population density and landscape characteristics surrounding the killing site. Results Deer ked infestation prevalence was 100%, but infestation intensity varied from 0.001 to 1.405 keds/cm2. Ked intensity was highest in male yearlings (~1.5 years) and positively associated with longitude and Scots pine (Pinus sylvestris) dominated habitat and negatively associated with bogs and latitude. Moose population density during autumn showed a tendency to be positively associated, while altitude tended to be negatively associated with ked intensity. Conclusions Deer keds exploit the whole moose population within our study area, but are most prevalent in areas dominated by Scots pine. This is probably a reflection of Scots pine being the preferred winter browse for moose in areas with highest moose densities in winter. Ked intensity decreases towards the northwest and partly with increasing altitude, probably explained by the direction of dispersal and reduced temperature, respectively. Abundant deer ked harm humans and domestic animals. Moose management authorities should therefore be aware of the close relationship between moose, deer ked and habitat, using the knowledge as a

  3. Cornu cervi pantotrichum Pharmacopuncture Solution Facilitate Hair Growth in C57BL/6 Mice

    PubMed Central

    Lee, Seon-Yong; Lee, Dong-Jin; Kwon, Kang; Lee, Chang-Hyun; Shin, Hyun Jong; Kim, Jai Eun; Ha, Ki-Tae; Jeong, Han-Sol

    2016-01-01

    Objectives: Cornu cervi pantotrichum (CCP) has been widely used in Korean and China, as an anti-fatigue, anti-aging, and tonic agent to enhance the functions of the reproductive and the immune systems. Because CCP has various growth factors that play important roles in the development of hair follicles, we examined whether CCP pharmacopuncture solution (CCPPS) was capable of promoting hair growth in an animal model. Methods: One day after hair depilation, CCPPS were topically applied to the dorsal skin of C57BL/6 mice once a day for 15 days. Hair growth activity was evaluated by using macro- and microscopic observations. Dorsal skin tissues were stained with hematoxylin and eosin. Expressions of bromodeoxyuridine (BrdU), proliferating cell nuclear antigen (PCNA), and fibroblast growth factor (FGF)-7 were examined by using immunohistochemical staining. A reverse transcription polymerase chain reaction (RT-PCR) analysis was also conducted to measure the messenger RNA (mRNA) expression of FGF-7. Results: CCPPS induced more active hair growth than normal saline. Histologic analysis showed enlargement of the dermal papilla, elongation of the hair shaft, and expansion of hair thickness in CCPPS treated mice, indicating that CCPPS effectively induced the development of anagen. CCPPS treatment markedly increased the expressions of BrdU and PCNA in the hair follicles of C57BL/6 mice. In addition, CCPPS up regulated the expression of FGF-7, which plays an important role in the development of hair follicles. Conclusion: These results reveal that CCPPS facilitates hair re-growth by proliferation of hair follicular cells and up-regulation of FGF-7 and suggest that CCPPS can potentially be applied as an alternative treatment for patients with alopecia. PMID:27386145

  4. Circulation of Dirofilaria repens, Setaria tundra, and Onchocercidae species in Hungary during the period 2011-2013.

    PubMed

    Kemenesi, Gábor; Kurucz, Kornélia; Kepner, Anett; Dallos, Bianka; Oldal, Miklós; Herczeg, Róbert; Vajdovics, Péter; Bányai, Krisztián; Jakab, Ferenc

    2015-11-30

    Dirofilaria repens and recently Dirofilaria immitis are known to be endemic in Hungary. Since there is no related research on Dirofilaria carrier mosquito species from Hungary, we conducted a three-year mosquito surveillance study between 2011 and 2013. During the study period we examined 23,139 female mosquitoes with a generic filaria-specific TaqMan PCR assay, and characterized them by sequencing a 500 bp segment of 12S rRNA. An important result of our study was the detection of Setaria tundra and D. repens along with an unidentified Onchocercidae nematode. D. repens is known to be endemic in Hungary, however, the detection of S. tundra in all sampling sites throughout the study period indicates for the first time the endemicity of this parasite in Hungary. The Onchocercidae sp. nematode showed 95% nucleotide identity with previously detected unidentified nematodes from Germany, indicating a broader geographical distribution of this nematode in Europe. D. immitis specific DNA was not detected among the screened mosquitoes in this study. Here we report 11 mosquito species as potential vector organisms for local filarial infections, including Aedes vexans, Ochlerotatus annulipes, Ochlerotatus sticticus, Coquillettidia richiardii, Anopheles hyrcanus and Ochlerotatus rusticus. Dirofilaria development unit was calculated and the potential transmission period was estimated, which ranged between 65 and 113 days between sampling seasons. A relatively high infection rate (36.8%) was identified, which is a notable finding for veterinary and human health professionals. Moreover, the results of our study widen the group of possible mosquito vector species for D. repens and S. tundra in Central Europe. PMID:26412142

  5. Development and Genetic Control of Plant Architecture and Biomass in the Panicoid Grass, Setaria

    PubMed Central

    Mauro-Herrera, Margarita; Doust, Andrew N.

    2016-01-01

    The architecture of a plant affects its ability to compete for light and to respond to environmental stresses, thus affecting overall fitness and productivity. Two components of architecture, branching and height, were studied in 182 F7 recombinant inbred lines (RILs) at the vegetative, flowering and mature developmental stages in the panicoid C4 model grass system, Setaria. The RIL population was derived from a cross between domesticated S. italica (foxtail millet) and its wild relative S. viridis (green foxtail). In both field and greenhouse trials the wild parent was taller initially, started branching earlier, and flowered earlier, while the domesticated parent was shorter initially, but flowered later, producing a robust tall plant architecture with more nodes and leaves on the main culm and few or no branches. Biomass was highly correlated with height of the plant and number of nodes on the main culm, and generally showed a negative relationship with branch number. However, several of the RILs with the highest biomass in both trials were significantly more branched than the domesticated parent of the cross. Quantitative trait loci (QTL) analyses indicate that both height and branching are controlled by multiple genetic regions, often with QTL for both traits colocalizing in the same genomic regions. Genomic positions of several QTL colocalize with QTL in syntenic regions in other species and contain genes known to control branching and height in sorghum, maize, and switchgrass. Included in these is the ortholog of the rice SD-1 semi-dwarfing gene, which underlies one of the major Setaria height QTL. Understanding the relationships between height and branching patterns in Setaria, and their genetic control, is an important step to gaining a comprehensive knowledge of the development and genetic regulation of panicoid grass architecture. PMID:26985990

  6. Development and Genetic Control of Plant Architecture and Biomass in the Panicoid Grass, Setaria.

    PubMed

    Mauro-Herrera, Margarita; Doust, Andrew N

    2016-01-01

    The architecture of a plant affects its ability to compete for light and to respond to environmental stresses, thus affecting overall fitness and productivity. Two components of architecture, branching and height, were studied in 182 F7 recombinant inbred lines (RILs) at the vegetative, flowering and mature developmental stages in the panicoid C4 model grass system, Setaria. The RIL population was derived from a cross between domesticated S. italica (foxtail millet) and its wild relative S. viridis (green foxtail). In both field and greenhouse trials the wild parent was taller initially, started branching earlier, and flowered earlier, while the domesticated parent was shorter initially, but flowered later, producing a robust tall plant architecture with more nodes and leaves on the main culm and few or no branches. Biomass was highly correlated with height of the plant and number of nodes on the main culm, and generally showed a negative relationship with branch number. However, several of the RILs with the highest biomass in both trials were significantly more branched than the domesticated parent of the cross. Quantitative trait loci (QTL) analyses indicate that both height and branching are controlled by multiple genetic regions, often with QTL for both traits colocalizing in the same genomic regions. Genomic positions of several QTL colocalize with QTL in syntenic regions in other species and contain genes known to control branching and height in sorghum, maize, and switchgrass. Included in these is the ortholog of the rice SD-1 semi-dwarfing gene, which underlies one of the major Setaria height QTL. Understanding the relationships between height and branching patterns in Setaria, and their genetic control, is an important step to gaining a comprehensive knowledge of the development and genetic regulation of panicoid grass architecture. PMID:26985990

  7. Parasitic Diseases

    MedlinePlus

    ... a bug bite, or sexual contact. Some parasitic diseases are easily treated and some are not. Parasites ... be seen with the naked eye. Some parasitic diseases occur in the United States. Contaminated water supplies ...

  8. Parasitic Diseases

    MedlinePlus

    ... water, a bug bite, or sexual contact. Some parasitic diseases are easily treated and some are not. Parasites ... can be seen with the naked eye. Some parasitic diseases occur in the United States. Contaminated water supplies ...

  9. Corrosion Inhibition and Adsorption Behavior of Setaria verticillata Leaf Extract in 1M Sulphuric Acid

    NASA Astrophysics Data System (ADS)

    Muthukrishnan, P.; Jeyaprabha, B.; Prakash, P.

    2013-12-01

    Setaria verticillata leaf extract (SVLE) as corrosion inhibitor in 1M H2SO4 was investigated by weight loss techniques and electrochemical techniques at 308-328 K. Inhibition efficiency of SVLE was found to increase with increasing concentration but decreased with temperature. Polarization measurements revealed that SVLE acted as mixed-type inhibitor. Impedance diagrams showed that increasing of SVLE concentration increased charge transfer resistance and decreased double layer capacitance. The adsorption of SVLE on the mild surface obeyed the Langmuir adsorption isotherm. Protective film formation against corrosion was confirmed by SEM and FTIR.

  10. Gastrointestinal parasites of working donkeys of Ethiopia.

    PubMed

    Getachew, M; Trawford, A; Feseha, G; Reid, S W J

    2010-01-01

    The general prevalence and population composition of gastrointestinal and pulmonary helminths of working donkeys were studied. For the purpose 2935 working donkeys were coprologically examined for nematode and cestode, and 215 donkeys for trematode infections. Seven donkeys that died due to various health problems or were euthanased on a welfare ground were necropsied and the parasites were recovered and identified to the species level. The study was conducted during the periods 1996-1999.Coprological examination revealed 99% strongyle, 80% Fasciola, 51% Parascaris, 30% Gastrodiscus, 11% Strongyloides westeri, 8% cestodes and 2% Oxyuris equi infection prevalence. Over 55% of donkeys had more than 1000 eggs per gram of faeces (epg). Forty two different species of parasites consisting of 33 nematodes, 3 trematodes, 3 cestodes and 3 arthropod larvae were identified from postmortem examined donkeys. Among the nematodes 17 species of Cyathostominae and 7 species of Strongylinae were identified. Other parasites identified include, Habronema muscae, Draschia megastoma, Trichostrongylus axei, Strongyloides westeri, Anoplocephala perfoliata, Anoplocephala magna, Anoplocephaloides (Paranoplocephala) mamillana, Parascaris equorum, Fasciola hepatica, Fasciola gigantica, Gastrodiscus aegyptiacus, Dictyocaulus arnfieldi, Oxyuris equi, Probstmayria vivipara, Gasterophilus intestinalis, Gasterophilus nasalis, Rhinoestrus uzbekistanicus and Setaria equina. This study revealed that working donkeys in Ethiopia are infected with a range of helminths and arthropod larvae, which are representatives of the important pathogenic parasites found in equids worldwide. PMID:19548106

  11. The Use of Maleic Hydrazide for Effective Hybridization of Setaria viridis.

    PubMed

    Rizal, Govinda; Karki, Shanta; Garcia, Richard; Larazo, Nikki; Alcasid, Michael; Quick, William Paul

    2015-01-01

    An efficient method for crossing green foxtail (Setaria viridis) is currently lacking. S. viridis is considered to be the new model plant for the study of C4 system in monocots and so an effective crossing protocol is urgently needed. S. viridis is a small grass with C4-NADP (ME) type of photosynthesis and has the advantage of having small genome of about 515 Mb, small plant stature, short life cycle, multiple tillers, and profuse seed set, and hence is an ideal model species for research. The objectives of this project were to develop efficient methods of emasculation and pollination, and to speed up generation advancement. We assessed the response of S. viridis flowers to hot water treatment (48°C) and to different concentrations of gibberellic acid, abscisic acid, maleic hydrazide (MH), and kinetin. We found that 500 μM of MH was effective in the emasculation of S. viridis, whilst still retaining the receptivity of the stigma to pollination. We also report effective ways to accelerate the breeding cycle of S. viridis for research through the germination of mature as well as immature seeds in optimized culture media. We believe these findings will be of great interest to researchers using Setaria. PMID:25910193

  12. The Use of Maleic Hydrazide for Effective Hybridization of Setaria viridis

    PubMed Central

    Rizal, Govinda; Karki, Shanta; Garcia, Richard; Larazo, Nikki; Alcasid, Michael; Quick, William Paul

    2015-01-01

    An efficient method for crossing green foxtail (Setaria viridis) is currently lacking. S. viridis is considered to be the new model plant for the study of C4 system in monocots and so an effective crossing protocol is urgently needed. S. viridis is a small grass with C4-NADP (ME) type of photosynthesis and has the advantage of having small genome of about 515 Mb, small plant stature, short life cycle, multiple tillers, and profuse seed set, and hence is an ideal model species for research. The objectives of this project were to develop efficient methods of emasculation and pollination, and to speed up generation advancement. We assessed the response of S. viridis flowers to hot water treatment (48°C) and to different concentrations of gibberellic acid, abscisic acid, maleic hydrazide (MH), and kinetin. We found that 500 μM of MH was effective in the emasculation of S. viridis, whilst still retaining the receptivity of the stigma to pollination. We also report effective ways to accelerate the breeding cycle of S. viridis for research through the germination of mature as well as immature seeds in optimized culture media. We believe these findings will be of great interest to researchers using Setaria. PMID:25910193

  13. Genetic diversity and population structure of elite foxtail millet [Setaria italica (L.) P. Beauv.] germplasm in China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    China is among the countries that have the most severe water deficiency. Due to its excellent drought tolerance, foxtail millet [Setaria italica (L.) P. Beauv.] has become one of the important cereal crops in China. Information on genetic diversity and population structure of foxtail millet may faci...

  14. In search of a potential diagnostic tool for molecular characterization of lymphatic filariasis.

    PubMed

    Saeed, Mohd; Adnan, Mohd; Khan, Saif; Al-Shammari, Eyad; Mustafa, Huma

    2016-01-01

    Lymphatic filariasis (LF) is a chronic disease and is caused by the parasites Wuchereria bancrofti (W. bancrofti), Brugia malayi (B. malayi) and Brugia timori (B. timori). In the present study, Setaria cervi (S. cervi), a bovine filarial parasite has been used. Previously, it has been reported that the S. cervi shares some common proteins and antigenic determinants with that of human filarial parasite. The larval stages of filarial species usually cannot be identified by classical morphology. Hence, molecular characterization allows the identification of the parasites throughout all their developmental stages. The genomic DNA of S. cervi adult were isolated and estimated spectrophotometrically for the quantitative presence of DNA content. Screening of DNA sequences from filarial DNA GenBank and Expressed Sequence Tags (EST's) were performed for homologous sequences and then multiple sequence alignment was executed. The conserved sequences from multiple sequence alignment were used for In Silico primer designing. The successfully designed primers were used further in PCR amplifications. Therefore, in search of a promising diagnostic tool few genes were identified to be conserved in the human and bovine filariasis and these novel primers deigned may help to develop a promising diagnostic tool for identification of lymphatic filariasis. PMID:26751881

  15. Interacting parasites

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2010-01-01

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

  16. Nucleotide Sequence Diversity and Linkage Disequilibrium of Four Nuclear Loci in Foxtail Millet (Setaria italica)

    PubMed Central

    He, Shui-lian; Yang, Yang; Morrell, Peter L.; Yi, Ting-shuang

    2015-01-01

    Foxtail millet (Setaria italica (L.) Beauv) is one of the earliest domesticated grains, which has been cultivated in northern China by 8,700 years before present (YBP) and across Eurasia by 4,000 YBP. Owing to a small genome and diploid nature, foxtail millet is a tractable model crop for studying functional genomics of millets and bioenergy grasses. In this study, we examined nucleotide sequence diversity, geographic structure, and levels of linkage disequilibrium at four nuclear loci (ADH1, G3PDH, IGS1 and TPI1) in representative samples of 311 landrace accessions across its cultivated range. Higher levels of nucleotide sequence and haplotype diversity were observed in samples from China relative to other sampled regions. Genetic assignment analysis classified the accessions into seven clusters based on nucleotide sequence polymorphisms. Intralocus LD decayed rapidly to half the initial value within ~1.2 kb or less. PMID:26325578

  17. Parasites: Water

    MedlinePlus

    ... Tropical Diseases Laboratory Diagnostic Assistance [DPDx] Parasites Home Water Recommend on Facebook Tweet Share Compartir Parasites can live in natural water sources. When outdoors, treat your water before drinking ...

  18. Parasitic colitis.

    PubMed

    Hechenbleikner, Elizabeth M; McQuade, Jennifer A

    2015-06-01

    Over one billion people worldwide harbor intestinal parasites. Parasitic intestinal infections have a predilection for developing countries due to overcrowding and poor sanitation but are also found in developed nations, such as the United States, particularly in immigrants or in the setting of sporadic outbreaks. Although the majority of people are asymptomatically colonized with parasites, the clinical presentation can range from mild abdominal discomfort or diarrhea to serious complications, such as perforation or bleeding. Protozoa and helminths (worms) are the two major classes of intestinal parasites. Protozoal intestinal infections include cryptosporidiosis, cystoisosporiasis, cyclosporiasis, balantidiasis, giardiasis, amebiasis, and Chagas disease, while helminth infections include ascariasis, trichuriasis, strongyloidiasis, enterobiasis, and schistosomiasis. Intestinal parasites are predominantly small intestine pathogens but the large intestine is also frequently involved. This article highlights important aspects of parasitic infections of the colon including epidemiology, transmission, symptoms, and diagnostic methods as well as appropriate medical and surgical treatment. PMID:26034403

  19. Parasitic Colitis

    PubMed Central

    Hechenbleikner, Elizabeth M.; McQuade, Jennifer A.

    2015-01-01

    Over one billion people worldwide harbor intestinal parasites. Parasitic intestinal infections have a predilection for developing countries due to overcrowding and poor sanitation but are also found in developed nations, such as the United States, particularly in immigrants or in the setting of sporadic outbreaks. Although the majority of people are asymptomatically colonized with parasites, the clinical presentation can range from mild abdominal discomfort or diarrhea to serious complications, such as perforation or bleeding. Protozoa and helminths (worms) are the two major classes of intestinal parasites. Protozoal intestinal infections include cryptosporidiosis, cystoisosporiasis, cyclosporiasis, balantidiasis, giardiasis, amebiasis, and Chagas disease, while helminth infections include ascariasis, trichuriasis, strongyloidiasis, enterobiasis, and schistosomiasis. Intestinal parasites are predominantly small intestine pathogens but the large intestine is also frequently involved. This article highlights important aspects of parasitic infections of the colon including epidemiology, transmission, symptoms, and diagnostic methods as well as appropriate medical and surgical treatment. PMID:26034403

  20. Anticancer activity of Ophiobolin A, isolated from the endophytic fungus Bipolaris setariae.

    PubMed

    Bhatia, Dimple R; Dhar, Payal; Mutalik, Varun; Deshmukh, Sunil Kumar; Verekar, Shilpa A; Desai, Dattatraya C; Kshirsagar, Rajendra; Thiagarajan, Padma; Agarwal, Veena

    2016-06-01

    The present work describes the anticancer activity of Ophiobolin A isolated from the endophytic fungus Bipolaris setariae. Ophiobolin A was isolated using preparative HPLC and its structure was confirmed by HRMS, (1)H NMR, (13)C NMR, COSY, DEPT, HSQC and HMBC. It inhibited solid and haematological cancer cell proliferation with IC50 of 0.4-4.3 μM. In comparison, IC50 against normal cells was 20.9 μM. It was found to inhibit the phosphorylation of S6 (IC50 = 1.9 ± 0.2 μM), ERK (IC50 = 0.28 ± 0.02 μM) and RB (IC50 = 1.42 ± 0.1 μM), the effector proteins of PI3K/mTOR, Ras/Raf/ERK and CDK/RB pathways, respectively. It induced apoptosis and inhibited cell cycle progression in MDA-MB-231 cancer cells with concomitant inhibition of signalling proteins. Thus, this study reveals that anticancer activity of Ophiobolin A is associated with simultaneous inhibition of multiple oncogenic signalling pathways namely PI3K/mTOR, Ras/Raf/ERK and CDK/RB. PMID:26212208

  1. Effects of abiotic stress on physiological plasticity and water use of Setaria viridis (L.).

    PubMed

    Saha, Prasenjit; Sade, Nir; Arzani, Ahmad; Rubio Wilhelmi, Maria Del Mar; Coe, Kevin M; Li, Bosheng; Blumwald, Eduardo

    2016-10-01

    The emerging model Setaria viridis with its C4 photosynthesis and adaptation to hot and dry locations is a promising system to investigate water use and abiotic stress tolerance. We investigated the physiological plasticity of six S. viridis natural accessions that originated from different regions of the world under normal conditions and conditions of water-deficit stress and high temperatures. Accessions Zha-1, A10.1 and Ula-1 showed significantly higher leaf water potential (Ψleaf), photosynthesis (A), transpiration (E), and stomatal conductance (gs) rates compared to Ast-1, Aba-1 and Sha-1 when grown under stress conditions. Expression analysis of genes associated with C4 photosynthesis, aquaporins, ABA biosynthesis and signaling including genes involved in stress revealed an increased sensitivity of Ast-1, Aba-1 and Sha-1 to stresses. Correlation analysis of gene expression data with physiological and biochemical changes characterized A10.1 and Ast-1 as two extreme tolerant and sensitive accessions originated from United States and Azerbaijan under water-deficit and heat stress, respectively. Although preliminary, our study demonstrated the plasticity of S. viridis accessions under stress, and allows the identification of tolerant and sensitive accessions that could be use to study the mechanisms associated with stress tolerance and to characterize of the regulatory networks involved in C4 grasses. PMID:27593471

  2. Genetic Diversity and Population Structure of Chinese Foxtail Millet [Setaria italica (L.) Beauv.] Landraces

    PubMed Central

    Wang, Chunfang; Jia, Guanqing; Zhi, Hui; Niu, Zhengang; Chai, Yang; Li, Wei; Wang, Yongfang; Li, Haiquan; Lu, Ping; Zhao, Baohua; Diao, Xianmin

    2012-01-01

    As an ancient cereal of great importance for dryland agriculture even today, foxtail millet (Setaria italica) is fast becoming a new plant genomic model crop. A genotypic analysis of 250 foxtail millet landraces, which represent 1% of foxtail millet germplasm kept in the Chinese National Gene Bank (CNGB), was conducted with 77 SSRs covering the foxtail millet genome. A high degree of molecular diversity among the landraces was found, with an average of 20.9 alleles per locus detected. STRUCTURE, neighbor-jointing, and principal components analyses classify the accessions into three clusters (topmost hierarchy) and, ultimately, four conservative subgroups (substructuring within the topmost clusters) in total, which are in good accordance with eco-geographical distribution in China. The highest subpopulation diversity was identified in the accessions of Pop3 from the middle regions of the Yellow River, followed by accessions in Pop1 from the downstream regions of the Yellow River, suggesting that foxtail millet was domesticated in the Yellow River drainage area first and then spread to other parts of the country. Linkage disequilibrium (LD) decay of less than 20 cM of genetic distance in the foxtail millet landrace genome was observed, which suggests that it could be possible to achieve resolution down to the 20 cM level for association mapping. PMID:22870400

  3. Microsatellite Variations of Elite Setaria Varieties Released during Last Six Decades in China

    PubMed Central

    Schnable, James C.; Niu, Zhengang; Wang, Chunfang; Li, Yuhui; Wang, Shujun; Wang, Suying; Liu, Jinrong; Guo, Erhu; Zhi, Hui; Diao, Xianmin

    2015-01-01

    Crop improvement is a multifaceted micro-evolutionary process, involving changes in breeding approaches, planting configurations and consumption preferences of human beings. Recent research has started to identify the specific genes or genomic regions correlate to improved agronomic traits, however, an apparent blank between the genetic structure of crop elite varieties and their improving histories in diverse modern breeding programs is still in existence. Foxtail millet (Setaria italica) was one of the earliest cereal crops to be domesticated and served as a staple crop for early civilizations in China, where it is still widely grown today. In the present trial, a panel of foxtail millet elite varieties, which were released in the last sixty years in different geographical regions of China, was characterized using microsatellite markers (SSRs). A clear separation of two subpopulations corresponding to the two eco-geographical regions of foxtail millet production in China was identified by the dataset, which also indicated that in more recently released elite varieties, large quantities of accessions have been transferred from spring-sowing to summer-sowing ecotypes, likely as a result of breeding response to planting configurations. An association mapping study was conducted to identify loci controlling traits of major agronomic interest. Furthermore, selective sweeps involved in improvement of foxtail millet were identified as multi-diverse minor effect loci controlling different agronomic traits during the long-term improvement of elite varieties. Our results highlight the effect of transition of planting configuration and breeding preference on genetic evolvement of crop species. PMID:25932649

  4. Development of multiplex PCR assay for authentication of Cornu Cervi Pantotrichum in traditional Chinese medicine based on cytochrome b and C oxidase subunit 1 genes.

    PubMed

    Gao, Lijun; Xia, Wei; Ai, Jinxia; Li, Mingcheng; Yuan, Guanxin; Niu, Jiamu; Fu, Guilian; Zhang, Lihua

    2016-07-01

    This study describes a method for discriminating the true Cervus antlers from its counterfeits using multiplex PCR. Bioinformatics were carried out to design the specific alleles primers for mitochondrial (mt) cytochrome b (Cyt b) and cytochrome C oxidase subunit 1 (Cox 1) genes. The mt DNA and genomic DNA were extracted from Cervi Cornu Pantotrichum through the modified alkaline and the salt-extracting method in addition to its counterfeits, respectively. Sufficient DNA templates were extracted from all samples used in two methods, and joint fragments of 354 bp and 543 bp that were specifically amplified from both of true Cervus antlers served as a standard control. The data revealed that the multiplex PCR-based assays using two primer sets can be used for forensic and quantitative identification of original Cervus deer products from counterfeit antlers in a single step. PMID:26287950

  5. Grain Yield and Quality of Foxtail Millet (Setaria italica L.) in Response to Tribenuron-Methyl

    PubMed Central

    Ning, Na; Yuan, Xiangyang; Dong, Shuqi; Wen, Yinyuan; Gao, Zhenpan; Guo, Meijun; Guo, Pingyi

    2015-01-01

    Foxtail millet (Setaria italica L.) is cultivated around the world for human and animal consumption. There is no suitable herbicide available for weed control in foxtail millet fields during the post-emergence stage. In this study, we investigated the effect and safety of the post-emergence herbicide tribenuron-methyl (TBM) on foxtail millet in terms of grain yield and quality using a split-plot field design. Field experiments were conducted using two varieties in 2013 and 2014, i.e., high-yielding hybrid Zhangzagu 10 and high-quality conventional Jingu 21. TBM treatments at 11.25 to 90 g ai ha−1 reduced root and shoot biomass and grain yield to varying degrees. In each of the two years, grain yield declined by 50.2% in Zhangzagu 10 with a herbicide dosage of 45 g ai ha−1 and by 45.2% in Jingu 21 with a herbicide dosage of 22.5 g ai ha−1 (recommended dosage). Yield reduction was due to lower grains per panicle, 1000-grain weight, panicle length, and panicle diameter. Grain yield was positively correlated with grains per panicle and 1000-grain weight, but not with panicles ha−1. With respect to grain protein content at 22.5 g ai ha−1, Zhangzagu 10 was similar to the control, whereas Jingu 21 was markedly lower. An increase in TBM dosage led to a decrease in grain Mn, Cu, Fe, and Zn concentrations. In conclusion, the recommended dosage of TBM was relatively safe for Zhangzagu 10, but not for Jingu 21. Additionally, the hybrid variety Zhangzagu 10 had a greater tolerance to TBM than the conventional variety Jingu 21. PMID:26565992

  6. Grain Yield and Quality of Foxtail Millet (Setaria italica L.) in Response to Tribenuron-Methyl.

    PubMed

    Ning, Na; Yuan, Xiangyang; Dong, Shuqi; Wen, Yinyuan; Gao, Zhenpan; Guo, Meijun; Guo, Pingyi

    2015-01-01

    Foxtail millet (Setaria italica L.) is cultivated around the world for human and animal consumption. There is no suitable herbicide available for weed control in foxtail millet fields during the post-emergence stage. In this study, we investigated the effect and safety of the post-emergence herbicide tribenuron-methyl (TBM) on foxtail millet in terms of grain yield and quality using a split-plot field design. Field experiments were conducted using two varieties in 2013 and 2014, i.e., high-yielding hybrid Zhangzagu 10 and high-quality conventional Jingu 21. TBM treatments at 11.25 to 90 g ai ha(-1) reduced root and shoot biomass and grain yield to varying degrees. In each of the two years, grain yield declined by 50.2% in Zhangzagu 10 with a herbicide dosage of 45 g ai ha(-1) and by 45.2% in Jingu 21 with a herbicide dosage of 22.5 g ai ha(-1) (recommended dosage). Yield reduction was due to lower grains per panicle, 1000-grain weight, panicle length, and panicle diameter. Grain yield was positively correlated with grains per panicle and 1000-grain weight, but not with panicles ha(-1). With respect to grain protein content at 22.5 g ai ha(-1,) Zhangzagu 10 was similar to the control, whereas Jingu 21 was markedly lower. An increase in TBM dosage led to a decrease in grain Mn, Cu, Fe, and Zn concentrations. In conclusion, the recommended dosage of TBM was relatively safe for Zhangzagu 10, but not for Jingu 21. Additionally, the hybrid variety Zhangzagu 10 had a greater tolerance to TBM than the conventional variety Jingu 21. PMID:26565992

  7. Methods for performing crosses in Setaria viridis, a new model system for the grasses.

    PubMed

    Jiang, Hui; Barbier, Hugues; Brutnell, Thomas

    2013-01-01

    Setaria viridis is an emerging model system for C4 grasses. It is closely related to the bioenergy feed stock switchgrass and the grain crop foxtail millet. Recently, the 510 Mb genome of foxtail millet, S. italica, has been sequenced (1,2) and a 25x coverage genome sequence of the weedy relative S. viridis is in progress. S. viridis has a number of characteristics that make it a potentially excellent model genetic system including a rapid generation time, small stature, simple growth requirements, prolific seed production (3) and developed systems for both transient and stable transformation (4). However, the genetics of S. viridis is largely unexplored, in part, due to the lack of detailed methods for performing crosses. To date, no standard protocol has been adopted that will permit rapid production of seeds from controlled crosses. The protocol presented here is optimized for performing genetic crosses in S. viridis, accession A10.1. We have employed a simple heat treatment with warm water for emasculation after pruning the panicle to retain 20-30 florets and labeling of flowers to eliminate seeds resulting from newly developed flowers after emasculation. After testing a series of heat treatments at permissive temperatures and varying the duration of dipping, we have established an optimum temperature and time range of 48 °C for 3-6 min. By using this method, a minimum of 15 crosses can be performed by a single worker per day and an average of 3-5 outcross progeny per panicle can be recovered. Therefore, an average of 45-75 outcross progeny can be produced by one person in a single day. Broad implementation of this technique will facilitate the development of recombinant inbred line populations of S. viridis X S. viridis or S. viridis X S. italica, mapping mutations through bulk segregant analysis and creating higher order mutants for genetic analysis. PMID:24121645

  8. Selection of reliable reference genes for RT-qPCR analysis during developmental stages and abiotic stress in Setaria viridis

    PubMed Central

    Martins, Polyana Kelly; Mafra, Valéria; de Souza, Wagner Rodrigo; Ribeiro, Ana Paula; Vinecky, Felipe; Basso, Marcos Fernando; da Cunha, Bárbara Andrade Dias Brito; Kobayashi, Adilson Kenji; Molinari, Hugo Bruno Correa

    2016-01-01

    Real-time PCR (RT-qPCR) expression analysis is a powerful analytical technique, but reliable results depend on the use of stable reference genes for proper normalization. This study proposed to test the expression stability of 13 candidate reference genes in Setaria viridis, a monocot species recently proposed as a new C4 model plant. Gene expression stability of these genes was assayed across different tissues and developmental stages of Setaria and under drought or aluminum stress. In general, our results showed Protein Kinase, RNA Binding Protein and SDH as the most stable genes. Moreover, pairwise analysis showed that two reference genes were sufficient to normalize the gene expression data under each condition. By contrast, GAPDH and ACT were the least stably expressed genes tested. Validation of suitable reference genes was carried out to profile the expression of P5CS and GolS during abiotic stress. In addition, normalization of gene expression of SuSy, involved in sugar metabolism, was assayed in the developmental dataset. This study provides a list of reliable reference genes for transcript normalization in S. viridis in different tissues and stages of development and under abiotic stresses, which will facilitate genetic studies in this monocot model plant. PMID:27321675

  9. Selection of reliable reference genes for RT-qPCR analysis during developmental stages and abiotic stress in Setaria viridis.

    PubMed

    Martins, Polyana Kelly; Mafra, Valéria; de Souza, Wagner Rodrigo; Ribeiro, Ana Paula; Vinecky, Felipe; Basso, Marcos Fernando; da Cunha, Bárbara Andrade Dias Brito; Kobayashi, Adilson Kenji; Molinari, Hugo Bruno Correa

    2016-01-01

    Real-time PCR (RT-qPCR) expression analysis is a powerful analytical technique, but reliable results depend on the use of stable reference genes for proper normalization. This study proposed to test the expression stability of 13 candidate reference genes in Setaria viridis, a monocot species recently proposed as a new C4 model plant. Gene expression stability of these genes was assayed across different tissues and developmental stages of Setaria and under drought or aluminum stress. In general, our results showed Protein Kinase, RNA Binding Protein and SDH as the most stable genes. Moreover, pairwise analysis showed that two reference genes were sufficient to normalize the gene expression data under each condition. By contrast, GAPDH and ACT were the least stably expressed genes tested. Validation of suitable reference genes was carried out to profile the expression of P5CS and GolS during abiotic stress. In addition, normalization of gene expression of SuSy, involved in sugar metabolism, was assayed in the developmental dataset. This study provides a list of reliable reference genes for transcript normalization in S. viridis in different tissues and stages of development and under abiotic stresses, which will facilitate genetic studies in this monocot model plant. PMID:27321675

  10. Molecular diversity and population structure of Chinese green foxtail [Setaria viridis (L.) Beauv.] revealed by microsatellite analysis

    PubMed Central

    Jia, Guanqing; Shi, Shenkui; Wang, Chunfang; Niu, Zhengang; Chai, Yang; Zhi, Hui; Diao, Xianmin

    2013-01-01

    Green foxtail (Setaria viridis) is a new model plant for the genomic investigation of C4 photosynthesis biology. As the ancestor of foxtail millet (Setaria italica), an ancient cereal of great importance in arid regions of the world, green foxtail is crucial for the study of domestication and evolution of this ancient crop. In the present study, 288 green foxtail accessions, which were collected from all geographical regions of China, were analysed using 77 simple sequence repeats (SSRs) that cover the whole genome. A high degree of molecular diversity was detected in these accessions, with an average of 33.5 alleles per locus. Two clusters, which were inconsistent with the distribution of eco-geographical regions in China, were inferred from STRUCTURE, Neighbor–Joining, and principal component analysis, indicating a partially mixed distribution of Chinese green foxtails. The higher subpopulation diversity was from accessions mainly collected from North China. A low level of linkage disequilibrium was observed in the green foxtail genome. Furthermore, a combined analysis of green foxtail and foxtail millet landraces was conducted, and the origin and domestication of foxtail millet was inferred in North China. PMID:23956411

  11. Parasitic Apologies

    ERIC Educational Resources Information Center

    Galatolo, Renata; Ursi, Biagio; Bongelli, Ramona

    2016-01-01

    The action of apologizing can be accomplished as the main business of the interaction or incidentally while participants are doing something else. We refer to these apologies as "parasitic apologies," because they are produced "en passant" (Schegloff, 2007), and focus our analysis on this type of apology occurring at the…

  12. Foodborne Parasites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foodborne infections are a significant cause of morbidity and mortality worldwide, and foodborne parasitic diseases, though not as widespread as bacterial and viral infections, are common on all continents and in most ecosystems, including arctic, temperate, and tropical regions. Certain foodborne ...

  13. Complete chloroplast genome sequence of green foxtail (Setaria viridis), a promising model system for C4 photosynthesis.

    PubMed

    Wang, Shuo; Gao, Li-Zhi

    2016-09-01

    The complete chloroplast genome of green foxtail (Setaria viridis), a promising model system for C4 photosynthesis, is first reported in this study. The genome harbors a large single copy (LSC) region of 81 016 bp and a small single copy (SSC) region of 12 456  bp separated by a pair of inverted repeat (IRa and IRb) regions of 22 315 bp. GC content is 38.92%. The proportion of coding sequence is 57.97%, comprising of 111 (19 duplicated in IR regions) unique genes, 71 of which are protein-coding genes, four are rRNA genes, and 36 are tRNA genes. Phylogenetic analysis indicated that S. viridis was clustered with its cultivated species S. italica in the tribe Paniceae of the family Poaceae. This newly determined chloroplast genome will provide valuable genetic resources to assist future studies on C4 photosynthesis in grasses. PMID:26305916

  14. Characteristics of PCR-SSCP and RAPD-HPCE methods for identifying authentication of Penis et testis cervi in Traditional Chinese Medicine based on cytochrome b gene.

    PubMed

    Li, Mingcheng; Gao, Lijun; Qu, Li; Sun, Jingyu; Yuan, Guangxin; Xia, Wei; Niu, Jiamu; Fu, Guilian; Zhang, Lihua

    2016-07-01

    The use of Penis et testis cervi, as a kind of precious Traditional Chinese Medicine (TCM), which is derived from dry deer's testis and penis, has been recorded for many years in China. There are abundant species of deer in China, the Penis et testis from species of Cervus Nippon and Cervus elaphusL were authentic, others species were defined as adulterant (different subspecies of deer) or counterfeits (different species). Identification of their origins or authenticity becomes a key in controlling the herbal products. A modified column chromatography was used to extract mitochondrial DNA of dried deer's testis and penis from sika deer (C. Nippon) and red deer (C. elaphusL) in addition to adulterants and counterfeits. Column chromatography requires for a short time to extract mitochondrial DNA of high purity with little damage of DNA molecules, which provides the primary structure of guarantee for the specific PCR; PCR-SSCP method showed a clear intra-specific difference among patterns of single-chain fragments, and completely differentiate Penis et testis origins from C. Nippon and C. elaphusL. RAPD-HPCE was based on the standard electropherograms to compute a control spectrum curve as similarity reference (R) among different samples. The similarity analysis indicated that there were significant inter-species differences among Penis et testis' adulterant or counterfeits. Both techniques provide a fast, simple, and accurate way to directly identify among inter-species or intra-species of Penis et testis. PMID:26309015

  15. Prevalence of non-strongyle gastrointestinal parasites of horses in Riyadh region of Saudi Arabia.

    PubMed

    Al Anazi, Abdullah D; Alyousif, Mohamed S

    2011-07-01

    This study aimed to provide recent data on the occurrence of non-strongyle intestinal parasite infestation in horses in the Riyadh region of Saudi Arabia as a basis for developing parasite control strategies. We conducted necropsy for 45 horses from September 2006 to November 2007 in the Riyadh region, Saudi Arabia. 39 out of 45 horses were infected with intestinal parasites with an infestation rate of 86.6%. Infestations with seven nematode species and two species of Gasterophilus larva were found. The most prevalent parasites were Strongyloides westeri (64.4%) and Parascaris equorum (28.8%) followed by Habronema muscae (22.2%). Trichostrongylus axei and Oxyuris equi were less common at (11.1%) and (8.8%), respectively. Habronema megastoma and Setaria equine were found in two horses only (4.4%). Gasterophilus intestinalis larvae were recovered from 39 horses (86.6%) and Gasterophilus nasalis larvae were found in 17 horses (37.7%). Season had a significant effect on the prevalence of P. equorum and G. nasalis, while age of horses had a significant effect only on the prevalence of P. equorum. The husbandry in Saudi Arabia appears to be conductive to parasites transmitted in stables or by insects rather than in pasture. PMID:23961139

  16. Prevalence of non-strongyle gastrointestinal parasites of horses in Riyadh region of Saudi Arabia

    PubMed Central

    AL Anazi, Abdullah D.; Alyousif, Mohamed S.

    2011-01-01

    This study aimed to provide recent data on the occurrence of non-strongyle intestinal parasite infestation in horses in the Riyadh region of Saudi Arabia as a basis for developing parasite control strategies. We conducted necropsy for 45 horses from September 2006 to November 2007 in the Riyadh region, Saudi Arabia. 39 out of 45 horses were infected with intestinal parasites with an infestation rate of 86.6%. Infestations with seven nematode species and two species of Gasterophilus larva were found. The most prevalent parasites were Strongyloides westeri (64.4%) and Parascaris equorum (28.8%) followed by Habronema muscae (22.2%). Trichostrongylus axei and Oxyuris equi were less common at (11.1%) and (8.8%), respectively. Habronema megastoma and Setaria equine were found in two horses only (4.4%). Gasterophilus intestinalis larvae were recovered from 39 horses (86.6%) and Gasterophilus nasalis larvae were found in 17 horses (37.7%). Season had a significant effect on the prevalence of P. equorum and G. nasalis, while age of horses had a significant effect only on the prevalence of P. equorum. The husbandry in Saudi Arabia appears to be conductive to parasites transmitted in stables or by insects rather than in pasture. PMID:23961139

  17. Protozoan Parasites.

    PubMed

    Custodio, Haidee

    2016-02-01

    • Stool antigen detection for Cryptosporidium sp, Giardia lamblia and Entamoeba histolytica are now commercially available, have better sensitivity and specificity than the traditional stool microscopy, and are less dependent on personnel skill. Tests employing newer techniques with faster turnaround time are also available for diagnosing trichomoniasis.• Nitazoxanide, the only U.S. Food and Drug Administration-approved medication for therapy of cryptosporidiosis, is effective among immunocompetent patients. However, on the basis of strong evidence from multiple clinical trials, nitazoxanide is considered ineffective among immunocompromised patients. (14) • Giardiasis can be asymptomatic or have a chronic course leading to malabsorption and failure to thrive. It can be treated with metronidazole, tinidazole, or nitazoxanide. On the basis of growing observational studies, postinfectious and extraintestinal manifestations of giardiasis occur, but the mechanisms are unclear. Given the high prevalence of giardiasis, public health implications need to be defined. (16) • Eradicating E histolytica from the gastrointestinal tract requires only intraluminal agent therapy. Therapy for invasive illnesses requires use of imidazole followed by intraluminal agents to eliminate persistent intraluminal parasites. • Malaria is considered the most lethal parasitic infection, with Plasmodium falciparum as the predominant cause of mortality. P vivax and P ovale can be dormant in the liver, and primaquine is necessary to resolve infection by P vivax and P ovale. • Among immunocompetent patients, infection with Toxoplasma gondii may be asymptomatic, involve localized lymphadenopathy, or cause ocular infection. In immunocompromised patients, reactivation or severe infection is not uncommon. On the basis of limited observational studies (there are no well-controlled randomized trials), therapy is recommended for acute infection during pregnancy to prevent transmission to the

  18. Temperature Responses of C4 Photosynthesis: Biochemical Analysis of Rubisco, Phosphoenolpyruvate Carboxylase, and Carbonic Anhydrase in Setaria viridis1[OPEN

    PubMed Central

    Boyd, Ryan A.; Gandin, Anthony; Cousins, Asaph B.

    2015-01-01

    The photosynthetic assimilation of CO2 in C4 plants is potentially limited by the enzymatic rates of Rubisco, phosphoenolpyruvate carboxylase (PEPc), and carbonic anhydrase (CA). Therefore, the activity and kinetic properties of these enzymes are needed to accurately parameterize C4 biochemical models of leaf CO2 exchange in response to changes in CO2 availability and temperature. There are currently no published temperature responses of both Rubisco carboxylation and oxygenation kinetics from a C4 plant, nor are there known measurements of the temperature dependency of the PEPc Michaelis-Menten constant for its substrate HCO3−, and there is little information on the temperature response of plant CA activity. Here, we used membrane inlet mass spectrometry to measure the temperature responses of Rubisco carboxylation and oxygenation kinetics, PEPc carboxylation kinetics, and the activity and first-order rate constant for the CA hydration reaction from 10°C to 40°C using crude leaf extracts from the C4 plant Setaria viridis. The temperature dependencies of Rubisco, PEPc, and CA kinetic parameters are provided. These findings describe a new method for the investigation of PEPc kinetics, suggest an HCO3− limitation imposed by CA, and show similarities between the Rubisco temperature responses of previously measured C3 species and the C4 plant S. viridis. PMID:26373659

  19. Tolerance to high soil temperature in foxtail millet (Setaria italica L.) is related to shoot and root growth and metabolism.

    PubMed

    Aidoo, Moses Kwame; Bdolach, Eyal; Fait, Aaron; Lazarovitch, Naftali; Rachmilevitch, Shimon

    2016-09-01

    Roots play important roles in regulating whole-plant carbon and water relations in response to extreme soil temperature. Three foxtail millet (Setaria italica L.) lines (448-Ames 21521, 463-P1391643 and 523-P1219619) were subjected to two different soil temperatures (28 and 38 °C). The gas exchange, chlorophyll fluorescence, root morphology and central metabolism of leaves and roots were studied at the grain-filling stage. High soil temperature (38 °C) significantly influenced the shoot transpiration, stomatal conductance, photosynthesis, root growth and metabolism of all lines. The root length and area were significantly reduced in lines 448 and 463 in response to the stress, while only a small non-specific reduction was observed in line 523 in response to the treatment. The shift of root metabolites in response to high soil temperature was also genotype specific. In response to high soil temperature, glutamate, proline and pyroglutamate were reduced in line 448, and alanine, aspartate, glycine, pyroglutamate, serine, threonine and valine were accumulated in line 463. In the roots of line 523, serine, threonine, valine, isomaltose, maltose, raffinose, malate and itaconate were accumulated. Root tolerance to high soil temperature was evident in line 523, in its roots growth potential, lower photosynthesis and stomatal conductance rates, and effective utilization and assimilation of membrane carbon and nitrogen, coupled with the accumulation of protective metabolites. PMID:27149034

  20. Gene mapping and functional analysis of the novel leaf color gene SiYGL1 in foxtail millet [Setaria italica (L.) P. Beauv].

    PubMed

    Li, Wen; Tang, Sha; Zhang, Shuo; Shan, Jianguo; Tang, Chanjuan; Chen, Qiannan; Jia, Guanqing; Han, Yuanhuai; Zhi, Hui; Diao, Xianmin

    2016-05-01

    Setaria italica and its wild ancestor Setaria viridis are emerging as model systems for genetics and functional genomics research. However, few systematic gene mapping or functional analyses have been reported in these promising C4 models. We herein isolated the yellow-green leaf mutant (siygl1) in S. italica using forward genetics approaches. Map-based cloning revealed that SiYGL1, which is a recessive nuclear gene encoding a magnesium-chelatase D subunit (CHLD), is responsible for the mutant phenotype. A single Phe to Leu amino acid change occurring near the ATPase-conserved domain resulted in decreased chlorophyll (Chl) accumulation and modified chloroplast ultrastructure. However, the mutation enhanced the light-use efficiency of the siygl1 mutant, suggesting that the mutated CHLD protein does not completely lose its original activity, but instead, gains novel features. A transcriptional analysis of Chl a oxygenase revealed that there is a strong negative feedback control of Chl b biosynthesis in S. italica. The SiYGL1 mRNA was expressed in all examined tissues, with higher expression observed in the leaves. Comparison of gene expression profiles in wild-type and siygl1 mutant plants indicated that SiYGL1 regulates a subset of genes involved in photosynthesis (rbcL and LHCB1), thylakoid development (DEG2) and chloroplast signaling (SRP54CP). These results provide information regarding the mutant phenotype at the transcriptional level. This study demonstrated that the genetic material of a Setaria species could be ideal for gene discovery investigations using forward genetics approaches and may help to explain the molecular mechanisms associated with leaf color variation. PMID:26559175

  1. Global analysis of WRKY transcription factor superfamily in Setaria identifies potential candidates involved in abiotic stress signaling

    PubMed Central

    Muthamilarasan, Mehanathan; Bonthala, Venkata S.; Khandelwal, Rohit; Jaishankar, Jananee; Shweta, Shweta; Nawaz, Kashif; Prasad, Manoj

    2015-01-01

    Transcription factors (TFs) are major players in stress signaling and constitute an integral part of signaling networks. Among the major TFs, WRKY proteins play pivotal roles in regulation of transcriptional reprogramming associated with stress responses. In view of this, genome- and transcriptome-wide identification of WRKY TF family was performed in the C4model plants, Setaria italica (SiWRKY) and S. viridis (SvWRKY), respectively. The study identified 105 SiWRKY and 44 SvWRKY proteins that were computationally analyzed for their physicochemical properties. Sequence alignment and phylogenetic analysis classified these proteins into three major groups, namely I, II, and III with majority of WRKY proteins belonging to group II (53 SiWRKY and 23 SvWRKY), followed by group III (39 SiWRKY and 11 SvWRKY) and group I (10 SiWRKY and 6 SvWRKY). Group II proteins were further classified into 5 subgroups (IIa to IIe) based on their phylogeny. Domain analysis showed the presence of WRKY motif and zinc finger-like structures in these proteins along with additional domains in a few proteins. All SiWRKY genes were physically mapped on the S. italica genome and their duplication analysis revealed that 10 and 8 gene pairs underwent tandem and segmental duplications, respectively. Comparative mapping of SiWRKY and SvWRKY genes in related C4 panicoid genomes demonstrated the orthologous relationships between these genomes. In silico expression analysis of SiWRKY and SvWRKY genes showed their differential expression patterns in different tissues and stress conditions. Expression profiling of candidate SiWRKY genes in response to stress (dehydration and salinity) and hormone treatments (abscisic acid, salicylic acid, and methyl jasmonate) suggested the putative involvement of SiWRKY066 and SiWRKY082 in stress and hormone signaling. These genes could be potential candidates for further characterization to delineate their functional roles in abiotic stress signaling. PMID:26635818

  2. Identification and Molecular Characterization of MYB Transcription Factor Superfamily in C4 Model Plant Foxtail Millet (Setaria italica L.)

    PubMed Central

    Muthamilarasan, Mehanathan; Khandelwal, Rohit; Yadav, Chandra Bhan; Bonthala, Venkata Suresh; Khan, Yusuf; Prasad, Manoj

    2014-01-01

    MYB proteins represent one of the largest transcription factor families in plants, playing important roles in diverse developmental and stress-responsive processes. Considering its significance, several genome-wide analyses have been conducted in almost all land plants except foxtail millet. Foxtail millet (Setaria italica L.) is a model crop for investigating systems biology of millets and bioenergy grasses. Further, the crop is also known for its potential abiotic stress-tolerance. In this context, a comprehensive genome-wide survey was conducted and 209 MYB protein-encoding genes were identified in foxtail millet. All 209 S. italica MYB (SiMYB) genes were physically mapped onto nine chromosomes of foxtail millet. Gene duplication study showed that segmental- and tandem-duplication have occurred in genome resulting in expansion of this gene family. The protein domain investigation classified SiMYB proteins into three classes according to number of MYB repeats present. The phylogenetic analysis categorized SiMYBs into ten groups (I - X). SiMYB-based comparative mapping revealed a maximum orthology between foxtail millet and sorghum, followed by maize, rice and Brachypodium. Heat map analysis showed tissue-specific expression pattern of predominant SiMYB genes. Expression profiling of candidate MYB genes against abiotic stresses and hormone treatments using qRT-PCR revealed specific and/or overlapping expression patterns of SiMYBs. Taken together, the present study provides a foundation for evolutionary and functional characterization of MYB TFs in foxtail millet to dissect their functions in response to environmental stimuli. PMID:25279462

  3. Global analysis of WRKY transcription factor superfamily in Setaria identifies potential candidates involved in abiotic stress signaling.

    PubMed

    Muthamilarasan, Mehanathan; Bonthala, Venkata S; Khandelwal, Rohit; Jaishankar, Jananee; Shweta, Shweta; Nawaz, Kashif; Prasad, Manoj

    2015-01-01

    Transcription factors (TFs) are major players in stress signaling and constitute an integral part of signaling networks. Among the major TFs, WRKY proteins play pivotal roles in regulation of transcriptional reprogramming associated with stress responses. In view of this, genome- and transcriptome-wide identification of WRKY TF family was performed in the C4model plants, Setaria italica (SiWRKY) and S. viridis (SvWRKY), respectively. The study identified 105 SiWRKY and 44 SvWRKY proteins that were computationally analyzed for their physicochemical properties. Sequence alignment and phylogenetic analysis classified these proteins into three major groups, namely I, II, and III with majority of WRKY proteins belonging to group II (53 SiWRKY and 23 SvWRKY), followed by group III (39 SiWRKY and 11 SvWRKY) and group I (10 SiWRKY and 6 SvWRKY). Group II proteins were further classified into 5 subgroups (IIa to IIe) based on their phylogeny. Domain analysis showed the presence of WRKY motif and zinc finger-like structures in these proteins along with additional domains in a few proteins. All SiWRKY genes were physically mapped on the S. italica genome and their duplication analysis revealed that 10 and 8 gene pairs underwent tandem and segmental duplications, respectively. Comparative mapping of SiWRKY and SvWRKY genes in related C4 panicoid genomes demonstrated the orthologous relationships between these genomes. In silico expression analysis of SiWRKY and SvWRKY genes showed their differential expression patterns in different tissues and stress conditions. Expression profiling of candidate SiWRKY genes in response to stress (dehydration and salinity) and hormone treatments (abscisic acid, salicylic acid, and methyl jasmonate) suggested the putative involvement of SiWRKY066 and SiWRKY082 in stress and hormone signaling. These genes could be potential candidates for further characterization to delineate their functional roles in abiotic stress signaling. PMID:26635818

  4. Parasites in Kentucky Thoroughbreds at necropsy: emphasis on stomach worms and tapeworms.

    PubMed

    Lyons, E T; Tolliver, S C; Drudge, J H; Swerczek, T W; Crowe, M W

    1983-05-01

    A total of 363 Thoroughbreds (62 males, 292 females, and 9 geldings), 1 to 26 years of age, were examined at necropsy for internal parasites for about a 12-month period from February 1981 through February 1982. Emphasis was on examining the stomach for nematodes and the small intestine and cecum for tapeworms. Parasites recovered from the stomach and infection rates were: Habronema spp--immature (24%), H muscae--adult (38%), Draschia megastoma--immature (13%), D megastoma--adult (62%), and Trichostrongylus axei--adult (4%); lesions caused by D megastoma were found upon gross observation in 58% of the stomachs. The tapeworm, Anoplocephala perfoliata, was recovered from 54% of the horses; A magna was not found. There was no obvious difference in infection rates of the stomach worms and tapeworms according to age or sex of the horses. Seasonal differences were apparent only for immature Habronema spp and immature D megastoma for which infection rates began increasing in June, peaking in October, and declining thereafter. Presence of 4 additional species of parasites was recorded, but only a cursory examination was made for them. These were the large strongyles, Strongylus vulgaris, S edentatus, and S equinus, from the cecum and a filariid, Setaria spp (probably S equina), from the abdominal cavity, for which recovery rates from the horses were 8%, 8%, 1%, and 7%, respectively. PMID:6869991

  5. Parasites, Plants, and People.

    PubMed

    Johnson, Marion; Moore, Tony

    2016-06-01

    Anthelminthic resistance is acknowledged worldwide and is a major problem in Aotearoa New Zealand, thus alternative parasite management strategies are imperative. One Health is an initiative linking animal, human, and environmental health. Parasites, plants, and people illustrate the possibilities of providing diverse diets for stock thereby lowering parasite burdens, improving the cultural wellbeing of a local community, and protecting the environment. PMID:27105933

  6. Parasites and supernormal manipulation.

    PubMed

    Holen, Ø H; Saetre, G P; Slagsvold, T; Stenseth, N C

    2001-12-22

    Social parasites may exploit their hosts by mimicking other organisms that the hosts normally benefit from investing in or responding to in some other way. Some parasites exaggerate key characters of the organisms they mimic, possibly in order to increase the response from the hosts. The huge gape and extreme begging intensity of the parasitic common cuckoo chick (Cuculus canorus) may be an example. In this paper, the evolutionary stability of manipulating hosts through exaggerated signals is analysed using game theory. Our model indicates that a parasite's signal intensity must be below a certain threshold in order to ensure acceptance and that this threshold depends directly on the rate of parasitism. The only evolutionarily stable strategy (ESS) combination is when hosts accept all signallers and parasites signal at their optimal signal intensity, which must be below the threshold. Supernormal manipulation by parasites is only evolutionarily stable under sufficiently low rates of parasitism. If the conditions for the ESS combination are not satisfied, rejector hosts can invade using signal intensity as a cue for identifying parasites. These qualitative predictions are discussed with respect to empirical evidence from parasitic mimicry systems that have been suggested to involve supernormal signalling, including evicting avian brood parasites and insect-mimicking Ophrys orchids. PMID:11749709

  7. Paradigms for parasite conservation.

    PubMed

    Dougherty, Eric R; Carlson, Colin J; Bueno, Veronica M; Burgio, Kevin R; Cizauskas, Carrie A; Clements, Christopher F; Seidel, Dana P; Harris, Nyeema C

    2016-08-01

    Parasitic species, which depend directly on host species for their survival, represent a major regulatory force in ecosystems and a significant component of Earth's biodiversity. Yet the negative impacts of parasites observed at the host level have motivated a conservation paradigm of eradication, moving us farther from attainment of taxonomically unbiased conservation goals. Despite a growing body of literature highlighting the importance of parasite-inclusive conservation, most parasite species remain understudied, underfunded, and underappreciated. We argue the protection of parasitic biodiversity requires a paradigm shift in the perception and valuation of their role as consumer species, similar to that of apex predators in the mid-20th century. Beyond recognizing parasites as vital trophic regulators, existing tools available to conservation practitioners should explicitly account for the unique threats facing dependent species. We built upon concepts from epidemiology and economics (e.g., host-density threshold and cost-benefit analysis) to devise novel metrics of margin of error and minimum investment for parasite conservation. We define margin of error as the risk of accidental host extinction from misestimating equilibrium population sizes and predicted oscillations, while minimum investment represents the cost associated with conserving the additional hosts required to maintain viable parasite populations. This framework will aid in the identification of readily conserved parasites that present minimal health risks. To establish parasite conservation, we propose an extension of population viability analysis for host-parasite assemblages to assess extinction risk. In the direst cases, ex situ breeding programs for parasites should be evaluated to maximize success without undermining host protection. Though parasitic species pose a considerable conservation challenge, adaptations to conservation tools will help protect parasite biodiversity in the face of

  8. Cultivation of parasites

    PubMed Central

    Ahmed, Nishat Hussain

    2014-01-01

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

  9. Leaf oxygen and Carbon Isotopic Signatures Reflect Drought Resistance and Water Use Efficiency in the C4 Grass, Setaria viridis

    NASA Astrophysics Data System (ADS)

    Ellsworth, P.; Cousins, A. B.

    2014-12-01

    Low water availability is a major constraint in crop production, especially as agriculture is pushed to marginal lands. Therefore, improving drought resistance such as increasing water use efficiency (WUE) through plant breeding is needed to expand the range of soil water availability adequate for food production. With the goal of finding the genomic basis for WUE in C4 grasses, Setaria viridis makes an ideal model species because of its small size, short lifespan, and sequenced genome. Also it is part of the panicoid grass clade, which is one of the most important clades for food and biofuel production. In plant breeding programs, large numbers of genotypes must be quickly screened for drought resistance traits, but there is no well-defined method of screening for WUE in C4 grasses. However, bulk leaf oxygen (Δ18OBL) and carbon (δ13C) isotopic signatures have shown potential as recorders of transpiration rate (E) and stomatal conductance (gs), and combined with biomass production potentially serve as a measure of WUE. Values of Δ18OBL record differences in transpiration rate because leaf water becomes more enriched as transpiration rate decreases, and leaf tissue records the isotopic composition of leaf water in which it is synthesized. Additionally, in C4 plants δ13C values decrease as gs decreases but the change in δ13C in response to gs may not be adequate to tease apart differences in WUE. In this study, we grew S. viridis plants under well-watered and water-limited conditions to determine if Δ18OBL and δ13C could be used as proxies for E and gs, and be used to screen S. viridis for differences in WUE in breeding programs. The Δ18OBL and δ13C were significantly different between well-watered and water-limited plants and correlated with each other and with E, gs, and instantaneous water use efficiency (Anet/gs). Therefore, Δ18OBL and δ13C can be useful proxies to screen genotypes for drought resistance by recording differences in E, gs, and WUE

  10. Increasing Selenium and Yellow Pigment Concentrations in Foxtail Millet (Setaria italica L.) Grain with Foliar Application of Selenite.

    PubMed

    Ning, Na; Yuan, Xiang-Yang; Dong, Shu-Qi; Wen, Yin-Yuan; Gao, Zhen-Pan; Guo, Mei-Jun; Guo, Ping-Yi

    2016-03-01

    Although addition of selenium (Se) is known to increase Se in crops, it is unclear whether exogenous Se is linked to nutritional and functional components in foxtail millet (Setaria italica L.). In this study, we examined the potential of increasing Se and yellow pigment (YP) in foxtail millet grain by foliar application of Se. Field experiments were conducted during the growing season of foxtail millet in 2013 and 2014 to assess the effects of foliar spray of sodium selenite (10-210 g Se ha(-1)) on the yield, Se uptake and accumulation, total YP, and microminerals in the grain. Average grain yields with Se application were 5.60 and 4.53 t ha(-1) in the 2 years, showing no significant differences from the unfertilized control. However, grain Se concentration increased linearly with Se application rate, by 8.92 and 6.09 μg kg(-1) in the 2 years with application of 1 g Se ha(-1) (maximum grain recovery rates of Se fertilizer, 52 and 28 %). Likewise, total grain YP concentration markedly increased by 0.038 and 0.031 mg kg(-1) in the 2 years with application of 1 g Se ha(-1). Grain Mn, Cu, Fe, and Zn concentrations were not significantly affected by Se application. This study indicated that foliar application of Se effectively and reliably increased the concentrations of Se and YP in foxtail millet grain without affecting the yield or mineral micronutrient concentrations. Thus, foliar-applied selenite has a significant potential to increase the concentrations of selenium and YP (putative lutein (Shen, J Cereal Sci 61:86-93, 2015; Abdel-Aal, Cereal Chem 79:455-457, 2002; Abdel-Aal, J Agric Food Chem 55:787-794, 2007)) of foxtail millet and, thus, the health benefits of this crop. PMID:26201681

  11. Intracellular Parasite Invasion Strategies

    NASA Astrophysics Data System (ADS)

    Sibley, L. D.

    2004-04-01

    Intracellular parasites use various strategies to invade cells and to subvert cellular signaling pathways and, thus, to gain a foothold against host defenses. Efficient cell entry, ability to exploit intracellular niches, and persistence make these parasites treacherous pathogens. Most intracellular parasites gain entry via host-mediated processes, but apicomplexans use a system of adhesion-based motility called ``gliding'' to actively penetrate host cells. Actin polymerization-dependent motility facilitates parasite migration across cellular barriers, enables dissemination within tissues, and powers invasion of host cells. Efficient invasion has brought widespread success to this group, which includes Toxoplasma, Plasmodium, and Cryptosporidium.

  12. Sphingolipids in parasitic protozoa

    PubMed Central

    Zhang, Kai; Bangs, James D.; Beverley, Stephen M.

    2009-01-01

    The surface of most protozoan parasites relies heavily upon lipid-anchored molecules, to form protective barriers and play critical functions required for infectivity. Sphingolipids (SLs) play important roles through their abundance and involvement in membrane microdomain formation, as well as serving as the lipid anchor for many of these molecules, and in some but possibly not all species, as important signaling molecules. Interactions of parasite sphingolipid metabolism with that of the host may potentially contribute to parasite survival and/or host defense. In this chapter we summarize current knowledge of SL structure, synthesis and function in several of the major parasitic protozoan groups. PMID:20919659

  13. Where are the parasites?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Review by E. Post et al. (“Ecological dynamics across the Arctic associated with recent climate change,” 11 September, p. 1355) paid little heed to parasites and other pathogens. The rapidly growing literature on parasites in arctic and subarctic ecosystems provides empirical and observational e...

  14. PARASITES OF FISH

    EPA Science Inventory

    The intent of this chapter is to describe the parasites of importance to fishes maintained and used in laboratory settings. In contrast to the frist edition, the focus will be only on those parasites that pose a serious threat to or are common in fishes held in these confined en...

  15. Peroxiredoxins in Parasites

    PubMed Central

    Gretes, Michael C.; Poole, Leslie B.

    2012-01-01

    Abstract Significance: Parasite survival and virulence relies on effective defenses against reactive oxygen and nitrogen species produced by the host immune system. Peroxiredoxins (Prxs) are ubiquitous enzymes now thought to be central to such defenses and, as such, have potential value as drug targets and vaccine antigens. Recent Advances: Plasmodial and kinetoplastid Prx systems are the most extensively studied, yet remain inadequately understood. For many other parasites our knowledge is even less well developed. Through parasite genome sequencing efforts, however, the key players are being discovered and characterized. Here we describe what is known about the biochemistry, regulation, and cell biology of Prxs in parasitic protozoa, helminths, and fungi. At least one Prx is found in each parasite with a sequenced genome, and a notable theme is the common patterns of expression, localization, and functionality among sequence-similar Prxs in related species. Critical Issues: The nomenclature of Prxs from parasites is in a state of disarray, causing confusion and making comparative inferences difficult. Here we introduce a systematic Prx naming convention that is consistent between organisms and informative about structural and evolutionary relationships. Future Directions: The new nomenclature should stimulate the crossfertilization of ideas among parasitologists and with the broader redox research community. The diverse parasite developmental stages and host environments present complex systems in which to explore the variety of roles played by Prxs, with a view toward parlaying what is learned into novel therapies and vaccines that are urgently needed. Antioxid. Redox Signal. 17, 608–633. PMID:22098136

  16. Reduction of parasitic lasing

    NASA Technical Reports Server (NTRS)

    Storm, Mark E. (Inventor)

    1994-01-01

    A technique was developed which carefully retro-reflects precisely controlled amounts of light back into a laser system thereby intentionally forcing the laser system components to oscillate in a new resonator called the parasitic oscillator. The parasitic oscillator uses the laser system to provide the gain and an external mirror is used to provide the output coupling of the new resonator. Any change of gain or loss inside the new resonator will directly change the lasing threshold of the parasitic oscillator. This change in threshold can be experimentally measured as a change in the absolute value of reflectivity, provided by the external mirror, necessary to achieve lasing in the parasitic oscillator. Discrepancies between experimental data and a parasitic oscillator model are direct evidence of optical misalignment or component performance problems. Any changes in the optical system can instantly be measured as a change in threshold for the parasitic oscillator. This technique also enables aligning the system for maximum parasitic suppression with the system fully operational.

  17. 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. PMID:27015610

  18. Diagnosis of Parasitic Diseases

    MedlinePlus

    ... Blood Food Insects Water Education and Training CDC Bottle Bioassay References and Resources How to Find A ... days, be examined. This test looks for ova (eggs) or the parasite. Your health care provider may ...

  19. Pets and Parasites

    MedlinePlus

    ... make me sick? Household pets such as dogs, cats, birds and reptiles can carry diseases or parasites ... might be used as litter boxes by neighborhood cats. Keep your children out of the dirt in ...

  20. Evolution: predator versus parasite.

    PubMed

    Stevens, Martin

    2014-05-19

    Both predators and brood parasites can be major threats to the reproduction of many birds. A new study shows that some cuckoo chicks can help deter nest predators, potentially improving host reproductive success when predation risks are high. PMID:24845665

  1. Parasites in marine food webs

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2013-01-01

    Most species interactions probably involve parasites. This review considers the extent to which marine ecologists should consider parasites to fully understand marine communities. Parasites are influential parts of food webs in estuaries, temperate reefs, and coral reefs, but their ecological importance is seldom recognized. Though difficult to observe, parasites can have substantial biomass, and they can be just as common as free-living consumers after controlling for body mass and trophic level. Parasites have direct impacts on the energetics of their hosts and some affect host behaviors, with ecosystem-level consequences. Although they cause disease, parasites are sensitive components of ecosystems. In particular, they suffer secondary extinctions due to biodiversity loss. Some parasites can also return to a system after habitat restoration. For these reasons, parasites can make good indicators of ecosystem integrity. Fishing can indirectly increase or decrease parasite populations and the effects of climate change on parasites are likely to be equally as complex.

  2. [Parasitic helminths of the cecum and colon of equidae in Italy].

    PubMed

    Ricci, M; Sabatini, A

    1992-12-01

    Intestinal helminths from coecum and colon were studied in 93 equidae including 40 horses, 36 donkeys and 17 mules. A total of 38 species, 36 nematodes and 2 cestodes, were identified as follows: 1) Triodontophorus serratus, 2) Triodontophorus brevicauda, 3) Strongylus equinus, 4) Strongylus edentatus, 5) Strongylus vulgaris, 6) Cyathostomum tetracanthum, 7) Cyathostomum coronatum, 8) Cyathostomum labiatum, 9) Cyathostomum labratum, 10) Cyathostomum alveatum, 11) Cyathostomum pateratum, 12) Cyathostomum catinatum, 13) Cyathostomum sagittatum, 14) Cylicodontophorus bicoronatus, 15) Cylicocyclus radiatus, 16) Cylicocyclus auriculatus, 17) Cylicocyclus elongatus, 18) Cylicocyclus nassatus, 19) Cylicocyclus insigne, 20) Cylicocyclus leptostomus, 21) Cylicostephanus calicatus, 22) Cylicostephanus poculatus, 23) Cylicostephanus minutus, 24) Cylicostephanus longibursatus, 25) Cylicostephanus hybridus, 26) Cylicostephanus goldi, 27) Cylicostephanus ornatus, 28) Cylicostephanus skrjabini, 29) Poteriostomum ratzii, 30) Gyalocephalus capitatus, 31) Parascaris equorum*, 32) Probstmayria vivipara, 33) Draschia megastoma*, 34) Habronema muscae*, 35) Habronema majus*, 36) Setaria equina*, 37) Anoplocephala perfoliata, 38) Paranoplocephala mamillana. The asterisked species are those not usually localized in the examined material. The most frequent parasites were found in all three hosts. Species 1, 4, 6, 9, 10, 12, 21, 22, 30 and 35 showed significant differences in prevalence between horses and donkeys, the mule generally having intermediate values. Multiple infections and total worm burden appear to decrease in older animals (> 15 years). Parasite associations occur mostly at random as expected from the values of the respective total prevalences. Some significant excesses on expected values were recorded but not significant deficits. The total worm burden increases with the number of parasite species and the increase appears to follow an exponential pattern. PMID:1339978

  3. Parasites alter community structure.

    PubMed

    Wood, Chelsea L; Byers, James E; Cottingham, Kathryn L; Altman, Irit; Donahue, Megan J; Blakeslee, April M H

    2007-05-29

    Parasites often play an important role in modifying the physiology and behavior of their hosts and may, consequently, mediate the influence hosts have on other components of an ecological community. Along the northern Atlantic coast of North America, the dominant herbivorous snail Littorina littorea structures rocky intertidal communities through strong grazing pressure and is frequently parasitized by the digenean trematode Cryptocotyle lingua. We hypothesized that the effects of parasitism on host physiology would induce behavioral changes in L. littorea, which in turn would modulate L. littorea's influence on intertidal community composition. Specifically, we hypothesized that C. lingua infection would alter the grazing rate of L. littorea and, consequently, macroalgal communities would develop differently in the presence of infected versus uninfected snails. Our results show that uninfected snails consumed 40% more ephemeral macroalgal biomass than infected snails in the laboratory, probably because the digestive system of infected snails is compromised by C. lingua infection. In the field, this weaker grazing by infected snails resulted in significantly greater expansion of ephemeral macroalgal cover relative to grazing by uninfected snails. By decreasing the per-capita grazing rate of the dominant herbivore, C. lingua indirectly affects the composition of the macroalgal community and may in turn affect other species that depend on macroalgae for resources or habitat structure. In light of the abundance of parasites across systems, we suggest that, through trait-mediated indirect effects, parasites may be a common determinant of structure in ecological communities. PMID:17517667

  4. Niche metabolism in parasitic protozoa

    PubMed Central

    Ginger, Michael L

    2005-01-01

    Complete or partial genome sequences have recently become available for several medically and evolutionarily important parasitic protozoa. Through the application of bioinformatics complete metabolic repertoires for these parasites can be predicted. For experimentally intractable parasites insight provided by metabolic maps generated in silico has been startling. At its more extreme end, such bioinformatics reckoning facilitated the discovery in some parasites of mitochondria remodelled beyond previous recognition, and the identification of a non-photosynthetic chloroplast relic in malarial parasites. However, for experimentally tractable parasites, mapping of the general metabolic terrain is only a first step in understanding how the parasite modulates its streamlined, yet still often puzzlingly complex, metabolism in order to complete life cycles within host, vector, or environment. This review provides a comparative overview and discussion of metabolic strategies used by several different parasitic protozoa in order to subvert and survive host defences, and illustrates how genomic data contribute to the elucidation of parasite metabolism. PMID:16553311

  5. Internal parasites of reptiles.

    PubMed

    Raś-Noryńska, Małgorzata; Sokół, Rajmund

    2015-01-01

    Nowadays a growing number of exotic reptiles are kept as pets. The aim of this study was to determine the species of parasites found in reptile patients of veterinary practices in Poland. Fecal samples obtained from 76 lizards, 15 turtles and 10 snakes were examined by flotation method and direct smear stained with Lugol's iodine. In 63 samples (62.4%) the presence of parasite eggs and oocysts was revealed. Oocysts of Isospora spp. (from 33% to 100% of the samples, depending on the reptilian species) and Oxyurids eggs (10% to 75%) were predominant. In addition, isolated Eimeria spp. oocysts and Giardia intestinalis cysts were found, as well as Strongylus spp. and Hymenolepis spp. eggs. Pet reptiles are often infected with parasites, some of which are potentially dangerous to humans. A routine parasitological examination should be done in such animals. PMID:26342508

  6. Gastrointestinal Parasitic Infections

    PubMed Central

    Embil, Juan A.; Embil, John M.

    1988-01-01

    This article surveys the most important gastrointestinal parasites that affect humans. The modes of acquisition, pathology, epidemiology, diagnosis, and treatment are all briefly examined. Gastrointestinal parasites have become increasingly important in the differential diagnosis of gastrointestinal disease, as a result of a number of circumstances. These circumstances include: increasing travel to developing countries; increased numbers, for one reason or another, of immunocompromised individuals; increased consumption of raw or partially cooked ethnic delicacies; more crowding in day-care centres; increased immigration from developing countries; and an endemic pocket of individuals with certain unhygienic or unsanitary practices. PMID:21253148

  7. A Remorin Gene SiREM6, the Target Gene of SiARDP, from Foxtail Millet (Setaria italica) Promotes High Salt Tolerance in Transgenic Arabidopsis

    PubMed Central

    Liu, Yuwei; Yu, Jingjuan

    2014-01-01

    Remorin proteins (REMs) form a plant-specific protein family, with some REMs being responsive to abiotic stress. However, the precise functions of REMs in abiotic stress tolerance are not clear. In this study, we identified 11 remorin genes from foxtail millet (Setaria italica) and cloned a remorin gene, SiREM6, for further investigation. The transcript level of SiREM6 was increased by high salt stress, low temperature stress and abscisic acid (ABA) treatment, but not by drought stress. The potential oligomerization of SiREM6 was examined by negative staining electron microscopy. The overexpression of SiREM6 improved high salt stress tolerance in transgenic Arabidopsis at the germination and seedling stages as revealed by germination rate, survival rate, relative electrolyte leakage and proline content. The SiREM6 promoter contains two dehydration responsive elements (DRE) and one ABA responsive element (ABRE). An ABA responsive DRE-binding transcription factor, SiARDP, and an ABRE-binding transcription factor, SiAREB1, were cloned from foxtail millet. SiARDP could physically bind to the DREs, but SiAREB1 could not. These results revealed that SiREM6 is a target gene of SiARDP and plays a critical role in high salt stress tolerance. PMID:24967625

  8. Ungulate malaria parasites.

    PubMed

    Templeton, Thomas J; Asada, Masahito; Jiratanh, Montakan; Ishikawa, Sohta A; Tiawsirisup, Sonthaya; Sivakumar, Thillaiampalam; Namangala, Boniface; Takeda, Mika; Mohkaew, Kingdao; Ngamjituea, Supawan; Inoue, Noboru; Sugimoto, Chihiro; Inagaki, Yuji; Suzuki, Yasuhiko; Yokoyama, Naoaki; Kaewthamasorn, Morakot; Kaneko, Osamu

    2016-01-01

    Haemosporida parasites of even-toed ungulates are diverse and globally distributed, but since their discovery in 1913 their characterization has relied exclusively on microscopy-based descriptions. In order to bring molecular approaches to bear on the identity and evolutionary relationships of ungulate malaria parasites, we conducted Plasmodium cytb-specific nested PCR surveys using blood from water buffalo in Vietnam and Thailand, and goats in Zambia. We found that Plasmodium is readily detectable from water buffalo in these countries, indicating that buffalo Plasmodium is distributed in a wider region than India, which is the only area in which buffalo Plasmodium has been reported. Two types (I and II) of Plasmodium sequences were identified from water buffalo and a third type (III) was isolated from goat. Morphology of the parasite was confirmed in Giemsa-reagent stained blood smears for the Type I sample. Complete mitochondrial DNA sequences were isolated and used to infer a phylogeny in which ungulate malaria parasites form a monophyletic clade within the Haemosporida, and branch prior to the clade containing bird, lizard and other mammalian Plasmodium. Thus it is likely that host switching of Plasmodium from birds to mammals occurred multiple times, with a switch to ungulates independently from other mammalian Plasmodium. PMID:26996979

  9. Parasitic Roundworm Diseases

    MedlinePlus

    ... The eggs or larvae also can enter the human body directly through the skin. With the exception of the parasitic roundworm that causes trichinosis, mature adult roundworms eventually end up or live in human intestines and cause infection and disease. In trichinosis, ...

  10. Parasite-related diarrhoeas*

    PubMed Central

    1980-01-01

    This article reviews available knowledge on the epidemiology, pathogenesis, clinical features, immunology, diagnosis, and therapy of parasite-related diarrhoeas of public health importance, primarily amoebiasis, giardiasis, trichuriasis, strongyloidiasis, balantidiasis, coccidioses, schistosomiasis, and capillariasis. Research priorities are recommended in each of these fields with the aim of developing better means of prevention and treatment. PMID:6971185

  11. Ungulate malaria parasites

    PubMed Central

    Templeton, Thomas J.; Asada, Masahito; Jiratanh, Montakan; Ishikawa, Sohta A.; Tiawsirisup, Sonthaya; Sivakumar, Thillaiampalam; Namangala, Boniface; Takeda, Mika; Mohkaew, Kingdao; Ngamjituea, Supawan; Inoue, Noboru; Sugimoto, Chihiro; Inagaki, Yuji; Suzuki, Yasuhiko; Yokoyama, Naoaki; Kaewthamasorn, Morakot; Kaneko, Osamu

    2016-01-01

    Haemosporida parasites of even-toed ungulates are diverse and globally distributed, but since their discovery in 1913 their characterization has relied exclusively on microscopy-based descriptions. In order to bring molecular approaches to bear on the identity and evolutionary relationships of ungulate malaria parasites, we conducted Plasmodium cytb-specific nested PCR surveys using blood from water buffalo in Vietnam and Thailand, and goats in Zambia. We found that Plasmodium is readily detectable from water buffalo in these countries, indicating that buffalo Plasmodium is distributed in a wider region than India, which is the only area in which buffalo Plasmodium has been reported. Two types (I and II) of Plasmodium sequences were identified from water buffalo and a third type (III) was isolated from goat. Morphology of the parasite was confirmed in Giemsa-reagent stained blood smears for the Type I sample. Complete mitochondrial DNA sequences were isolated and used to infer a phylogeny in which ungulate malaria parasites form a monophyletic clade within the Haemosporida, and branch prior to the clade containing bird, lizard and other mammalian Plasmodium. Thus it is likely that host switching of Plasmodium from birds to mammals occurred multiple times, with a switch to ungulates independently from other mammalian Plasmodium. PMID:26996979

  12. A Passion for Parasites

    PubMed Central

    Englund, Paul T.

    2014-01-01

    I knew nothing and had thought nothing about parasites until 1971. In fact, if you had asked me before then, I might have commented that parasites were rather disgusting. I had been at the Johns Hopkins School of Medicine for three years, and I was on the lookout for a new project. In 1971, I came across a paper in the Journal of Molecular Biology by Larry Simpson, a classmate of mine in graduate school. Larry's paper described a remarkable DNA structure known as kinetoplast DNA (kDNA), isolated from a parasite. kDNA, the mitochondrial genome of trypanosomatids, is a DNA network composed of several thousand interlocked DNA rings. Almost nothing was known about it. I was looking for a project on DNA replication, and I wanted it to be both challenging and important. I had no doubt that working with kDNA would be a challenge, as I would be exploring uncharted territory. I was also sure that the project would be important when I learned that parasites with kDNA threaten huge populations in underdeveloped tropical countries. Looking again at Larry's paper, I found the electron micrographs of the kDNA networks to be rather beautiful. I decided to take a chance on kDNA. Little did I know then that I would devote the next forty years of my life to studying kDNA replication. PMID:25336639

  13. Parasitic suppressing circuit

    NASA Technical Reports Server (NTRS)

    Fowler, J. T.; Raposa, F. L. (Inventor)

    1973-01-01

    A circuit for suppressing parasitic oscillations across an inductor operating in a resonant mode is described. The circuit includes a switch means and resistive means connected serially across the inductor. A unidirectional resistive-capacitive network is also connected across the inductor and to the switch means to automatically render the switch means conducting when inductive current through the inductor ceases to flow.

  14. Malaria diseases and parasites.

    PubMed

    Ascenzi, A

    1999-09-01

    The milestones in the discovery of malaria parasites and their relationships with malaria diseases are presented and discussed with particular reference to the contribution of the Italian scientists. Laveran's discovery (1880) of the malaria parasite produced some schepticism among the Roman scientists who were under the influence of Tommasi-Crudeli, the discoverer of the supposed Bacillus malariae. However, Marchiafava and Celli confirmed soon Laveran's observations and, between 1883 and 1885, improved the description of the parasite adding important details. They described, then, the aestivo-autumnal tertian fever as a distinct disease from the 'primaverile' or benign tertian. This work influenced Golgi who went on to analyse the features that distinguish the benign tertian parasite from that of the quartan. The fact that in North Italy the aestivo-autumnal tertian fever was hardly ever found, whereas it was common in the Roman Campagna and the Pontin marshes, explains why it was Celli and Marchiafava and later Bignami and Bastianelli, and Marchiafava and Bignami--but not Golgi--who were committed to work on this pernicious form of malaria. By the early 1890s the Italian scientists came to define the three malaria parasites, presently known as Plasmodium vivax, P. malariae, and P. falciparum, and to associate them with precise anatomo-pathological and clinical features. By the middle 1890s the Italian school was prepared to contribute also to the discovery of the mosquito cycle in human malaria, clearly hypothesized by Bignami in 1896 and experimentally proved in 1898 by Bignami, Bastianelli and Grassi. PMID:10697831

  15. Foodborne and waterborne parasites.

    PubMed

    Pozio, Edoardo

    2003-01-01

    More than 72 species of protozoan and helminth parasites can reach humans by food and water, and most of these infections are zoonoses. Some parasites show a cosmopolitan distribution, others a more restricted distribution due to their complex life cycles, which need the presence of one or more intermediate hosts. Of this large number of pathogens, only Toxoplasma gondii can be transmitted to humans by two different ways, i.e., by cysts present in infected meat and by oocysts contaminating food and water. Eleven helminthic species (Taenia saginata, Taenia solium, Taenia asiatica, Trichinella spiralis, Tr. nativa, Tr. britovi, Tr. pseudospiralis, Tr. murrelli, Tr nelsoni, Tr. papuae and Tr. zimbabwensis) can grow in meat of different animal species and can be transmitted to humans by the consumption of raw meat or meat products. Twenty trematode species, four cestode species and seven nematode species can infect humans through the consumption of raw sea- and/or fresh-water food (fishes, molluscs, frogs, tadpoles, camarons, crayfishes). Six species of Cryptosporidium, Isospora belli, Cyclospora cayetanensis, Giardia duodenalis and Entamoeba histolytica/E. dispar can contaminate food and water. Among the helminths, seven trematode species, seven cestode species and five species of nematodes can reach humans by contaminated food and water. Diagnostic and detection methods that can be carried out routinely on food and water samples are available only for few parasites (Cryptosporidium sp., Giardia sp., Anisakidae, Trichinella sp., Taenia sp.), i.e., for parasites which represent a risk to human populations living in industrialised countries. The majority of food and waterborne infections of parasitic origin are related to poverty, low sanitation, and old food habits. PMID:15058817

  16. Stool ova and parasites exam

    MedlinePlus

    Parasites and stool ova exam ... order this test if you have signs of parasites, diarrhea that does not go away, or other ... There are no parasites or eggs in the stool sample. Talk to your health care provider about the meaning of your specific test ...

  17. Evolutionary Origins of Rhizarian Parasites.

    PubMed

    Sierra, Roberto; Cañas-Duarte, Silvia J; Burki, Fabien; Schwelm, Arne; Fogelqvist, Johan; Dixelius, Christina; González-García, Laura N; Gile, Gillian H; Slamovits, Claudio H; Klopp, Christophe; Restrepo, Silvia; Arzul, Isabelle; Pawlowski, Jan

    2016-04-01

    The SAR group (Stramenopila, Alveolata, Rhizaria) is one of the largest clades in the tree of eukaryotes and includes a great number of parasitic lineages. Rhizarian parasites are obligate and have devastating effects on commercially important plants and animals but despite this fact, our knowledge of their biology and evolution is limited. Here, we present rhizarian transcriptomes from all major parasitic lineages in order to elucidate their evolutionary relationships using a phylogenomic approach. Our results suggest that Ascetosporea, parasites of marine invertebrates, are sister to the novel clade Apofilosa. The phytomyxean plant parasites branch sister to the vampyrellid algal ectoparasites in the novel clade Phytorhiza. They also show that Ascetosporea + Apofilosa + Retaria + Filosa + Phytorhiza form a monophyletic clade, although the branching pattern within this clade is difficult to resolve and appears to be model-dependent. Our study does not support the monophyly of the rhizarian parasitic lineages (Endomyxa), suggesting independent origins for rhizarian animal and plant parasites. PMID:26681153

  18. MARveling at parasite invasion.

    PubMed

    Hager, Kristin M; Carruthers, Vern B

    2008-02-01

    Micronemal proteins (MICs) are key mediators of cytoadherence and invasion for Toxoplasma gondii. Emerging evidence indicates that carbohydrate binding facilitates Toxoplasma entry into host cells. The recently solved Toxoplasma MIC1s (TgMIC1s) structure reveals the presence of novel specialized domains that can discriminate between glycan residues. Comparison with Plasmodium erythrocyte-binding antigen 175 reveals that terminal sialic acid residues might represent a shared but tailored invasion pathway among apicomplexan parasites. PMID:18203663

  19. Comprehensive Genome-Wide Survey, Genomic Constitution and Expression Profiling of the NAC Transcription Factor Family in Foxtail Millet (Setaria italica L.)

    PubMed Central

    Puranik, Swati; Sahu, Pranav Pankaj; Mandal, Sambhu Nath; B., Venkata Suresh; Parida, Swarup Kumar; Prasad, Manoj

    2013-01-01

    The NAC proteins represent a major plant-specific transcription factor family that has established enormously diverse roles in various plant processes. Aided by the availability of complete genomes, several members of this family have been identified in Arabidopsis, rice, soybean and poplar. However, no comprehensive investigation has been presented for the recently sequenced, naturally stress tolerant crop, Setaria italica (foxtail millet) that is famed as a model crop for bioenergy research. In this study, we identified 147 putative NAC domain-encoding genes from foxtail millet by systematic sequence analysis and physically mapped them onto nine chromosomes. Genomic organization suggested that inter-chromosomal duplications may have been responsible for expansion of this gene family in foxtail millet. Phylogenetically, they were arranged into 11 distinct sub-families (I-XI), with duplicated genes fitting into one cluster and possessing conserved motif compositions. Comparative mapping with other grass species revealed some orthologous relationships and chromosomal rearrangements including duplication, inversion and deletion of genes. The evolutionary significance as duplication and divergence of NAC genes based on their amino acid substitution rates was understood. Expression profiling against various stresses and phytohormones provides novel insights into specific and/or overlapping expression patterns of SiNAC genes, which may be responsible for functional divergence among individual members in this crop. Further, we performed structure modeling and molecular simulation of a stress-responsive protein, SiNAC128, proffering an initial framework for understanding its molecular function. Taken together, this genome-wide identification and expression profiling unlocks new avenues for systematic functional analysis of novel NAC gene family candidates which may be applied for improvising stress adaption in plants. PMID:23691254

  20. Evaluation of water-use efficiency in foxtail millet (Setaria italica) using visible-near infrared and thermal spectral sensing techniques.

    PubMed

    Wang, Meng; Ellsworth, Patrick Z; Zhou, Jianfeng; Cousins, Asaph B; Sankaran, Sindhuja

    2016-05-15

    Water limitations decrease stomatal conductance (g(s)) and, in turn, photosynthetic rate (A(net)), resulting in decreased crop productivity. The current techniques for evaluating these physiological responses are limited to leaf-level measures acquired by measuring leaf-level gas exchange. In this regard, proximal sensing techniques can be a useful tool in studying plant biology as they can be used to acquire plant-level measures in a high-throughput manner. However, to confidently utilize the proximal sensing technique for high-throughput physiological monitoring, it is important to assess the relationship between plant physiological parameters and the sensor data. Therefore, in this study, the application of rapid sensing techniques based on thermal imaging and visual-near infrared spectroscopy for assessing water-use efficiency (WUE) in foxtail millet (Setaria italica (L.) P. Beauv) was evaluated. The visible-near infrared spectral reflectance (350-2500 nm) and thermal (7.5-14 µm) data were collected at regular intervals from well-watered and drought-stressed plants in combination with other leaf physiological parameters (transpiration rate-E, A(net), g(s), leaf carbon isotopic signature-δ(13)C(leaf), WUE). Partial least squares regression (PLSR) analysis was used to predict leaf physiological measures based on the spectral data. The PLSR modeling on the hyperspectral data yielded accurate and precise estimates of leaf E, gs, δ(13)C(leaf), and WUE with coefficient of determination in a range of 0.85-0.91. Additionally, significant differences in average leaf temperatures (~1°C) measured with a thermal camera were observed between well-watered plants and drought-stressed plants. In summary, the visible-near infrared reflectance data, and thermal images can be used as a potential rapid technique for evaluating plant physiological responses such as WUE. PMID:26992551

  1. Integrative analysis and expression profiling of secondary cell wall genes in C4 biofuel model Setaria italica reveals targets for lignocellulose bioengineering

    PubMed Central

    Muthamilarasan, Mehanathan; Khan, Yusuf; Jaishankar, Jananee; Shweta, Shweta; Lata, Charu; Prasad, Manoj

    2015-01-01

    Several underutilized grasses have excellent potential for use as bioenergy feedstock due to their lignocellulosic biomass. Genomic tools have enabled identification of lignocellulose biosynthesis genes in several sequenced plants. However, the non-availability of whole genome sequence of bioenergy grasses hinders the study on bioenergy genomics and their genomics-assisted crop improvement. Foxtail millet (Setaria italica L.; Si) is a model crop for studying systems biology of bioenergy grasses. In the present study, a systematic approach has been used for identification of gene families involved in cellulose (CesA/Csl), callose (Gsl) and monolignol biosynthesis (PAL, C4H, 4CL, HCT, C3H, CCoAOMT, F5H, COMT, CCR, CAD) and construction of physical map of foxtail millet. Sequence alignment and phylogenetic analysis of identified proteins showed that monolignol biosynthesis proteins were highly diverse, whereas CesA/Csl and Gsl proteins were homologous to rice and Arabidopsis. Comparative mapping of foxtail millet lignocellulose biosynthesis genes with other C4 panicoid genomes revealed maximum homology with switchgrass, followed by sorghum and maize. Expression profiling of candidate lignocellulose genes in response to different abiotic stresses and hormone treatments showed their differential expression pattern, with significant higher expression of SiGsl12, SiPAL2, SiHCT1, SiF5H2, and SiCAD6 genes. Further, due to the evolutionary conservation of grass genomes, the insights gained from the present study could be extrapolated for identifying genes involved in lignocellulose biosynthesis in other biofuel species for further characterization. PMID:26583030

  2. Metabolic Reconstruction of Setaria italica: A Systems Biology Approach for Integrating Tissue-Specific Omics and Pathway Analysis of Bioenergy Grasses

    PubMed Central

    de Oliveira Dal'Molin, Cristiana G.; Orellana, Camila; Gebbie, Leigh; Steen, Jennifer; Hodson, Mark P.; Chrysanthopoulos, Panagiotis; Plan, Manuel R.; McQualter, Richard; Palfreyman, Robin W.; Nielsen, Lars K.

    2016-01-01

    The urgent need for major gains in industrial crops productivity and in biofuel production from bioenergy grasses have reinforced attention on understanding C4 photosynthesis. Systems biology studies of C4 model plants may reveal important features of C4 metabolism. Here we chose foxtail millet (Setaria italica), as a C4 model plant and developed protocols to perform systems biology studies. As part of the systems approach, we have developed and used a genome-scale metabolic reconstruction in combination with the use of multi-omics technologies to gain more insights into the metabolism of S. italica. mRNA, protein, and metabolite abundances, were measured in mature and immature stem/leaf phytomers, and the multi-omics data were integrated into the metabolic reconstruction framework to capture key metabolic features in different developmental stages of the plant. RNA-Seq reads were mapped to the S. italica resulting for 83% coverage of the protein coding genes of S. italica. Besides revealing similarities and differences in central metabolism of mature and immature tissues, transcriptome analysis indicates significant gene expression of two malic enzyme isoforms (NADP- ME and NAD-ME). Although much greater expression levels of NADP-ME genes are observed and confirmed by the correspondent protein abundances in the samples, the expression of multiple genes combined to the significant abundance of metabolites that participates in C4 metabolism of NAD-ME and NADP-ME subtypes suggest that S. italica may use mixed decarboxylation modes of C4 photosynthetic pathways under different plant developmental stages. The overall analysis also indicates different levels of regulation in mature and immature tissues in carbon fixation, glycolysis, TCA cycle, amino acids, fatty acids, lignin, and cellulose syntheses. Altogether, the multi-omics analysis reveals different biological entities and their interrelation and regulation over plant development. With this study, we demonstrated

  3. Metabolic Reconstruction of Setaria italica: A Systems Biology Approach for Integrating Tissue-Specific Omics and Pathway Analysis of Bioenergy Grasses.

    PubMed

    de Oliveira Dal'Molin, Cristiana G; Orellana, Camila; Gebbie, Leigh; Steen, Jennifer; Hodson, Mark P; Chrysanthopoulos, Panagiotis; Plan, Manuel R; McQualter, Richard; Palfreyman, Robin W; Nielsen, Lars K

    2016-01-01

    The urgent need for major gains in industrial crops productivity and in biofuel production from bioenergy grasses have reinforced attention on understanding C4 photosynthesis. Systems biology studies of C4 model plants may reveal important features of C4 metabolism. Here we chose foxtail millet (Setaria italica), as a C4 model plant and developed protocols to perform systems biology studies. As part of the systems approach, we have developed and used a genome-scale metabolic reconstruction in combination with the use of multi-omics technologies to gain more insights into the metabolism of S. italica. mRNA, protein, and metabolite abundances, were measured in mature and immature stem/leaf phytomers, and the multi-omics data were integrated into the metabolic reconstruction framework to capture key metabolic features in different developmental stages of the plant. RNA-Seq reads were mapped to the S. italica resulting for 83% coverage of the protein coding genes of S. italica. Besides revealing similarities and differences in central metabolism of mature and immature tissues, transcriptome analysis indicates significant gene expression of two malic enzyme isoforms (NADP- ME and NAD-ME). Although much greater expression levels of NADP-ME genes are observed and confirmed by the correspondent protein abundances in the samples, the expression of multiple genes combined to the significant abundance of metabolites that participates in C4 metabolism of NAD-ME and NADP-ME subtypes suggest that S. italica may use mixed decarboxylation modes of C4 photosynthetic pathways under different plant developmental stages. The overall analysis also indicates different levels of regulation in mature and immature tissues in carbon fixation, glycolysis, TCA cycle, amino acids, fatty acids, lignin, and cellulose syntheses. Altogether, the multi-omics analysis reveals different biological entities and their interrelation and regulation over plant development. With this study, we demonstrated

  4. Validating Internal Control Genes for the Accurate Normalization of qPCR Expression Analysis of the Novel Model Plant Setaria viridis

    PubMed Central

    Lambret-Frotté, Julia; de Almeida, Leandro C. S.; de Moura, Stéfanie M.; Souza, Flavio L. F.; Linhares, Francisco S.; Alves-Ferreira, Marcio

    2015-01-01

    Employing reference genes to normalize the data generated with quantitative PCR (qPCR) can increase the accuracy and reliability of this method. Previous results have shown that no single housekeeping gene can be universally applied to all experiments. Thus, the identification of a suitable reference gene represents a critical step of any qPCR analysis. Setaria viridis has recently been proposed as a model system for the study of Panicoid grasses, a crop family of major agronomic importance. Therefore, this paper aims to identify suitable S. viridis reference genes that can enhance the analysis of gene expression in this novel model plant. The first aim of this study was the identification of a suitable RNA extraction method that could retrieve a high quality and yield of RNA. After this, two distinct algorithms were used to assess the gene expression of fifteen different candidate genes in eighteen different samples, which were divided into two major datasets, the developmental and the leaf gradient. The best-ranked pair of reference genes from the developmental dataset included genes that encoded a phosphoglucomutase and a folylpolyglutamate synthase; genes that encoded a cullin and the same phosphoglucomutase as above were the most stable genes in the leaf gradient dataset. Additionally, the expression pattern of two target genes, a SvAP3/PI MADS-box transcription factor and the carbon-fixation enzyme PEPC, were assessed to illustrate the reliability of the chosen reference genes. This study has shown that novel reference genes may perform better than traditional housekeeping genes, a phenomenon which has been previously reported. These results illustrate the importance of carefully validating reference gene candidates for each experimental set before employing them as universal standards. Additionally, the robustness of the expression of the target genes may increase the utility of S. viridis as a model for Panicoid grasses. PMID:26247784

  5. Phosphate Concentration and Arbuscular Mycorrhizal Colonisation Influence the Growth, Yield and Expression of Twelve PHT1 Family Phosphate Transporters in Foxtail Millet (Setaria italica)

    PubMed Central

    Ceasar, S. Antony; Hodge, Angela; Baker, Alison; Baldwin, Stephen A.

    2014-01-01

    Phosphorus (P) is an essential element which plays several key roles in all living organisms. Setaria italica (foxtail millet) is a model species for panacoid grasses including several millet species widely grown in arid regions of Asia and Africa, and for the bioenergy crop switchgrass. The growth responses of S. italica to different levels of inorganic phosphate (Pi) and to colonisation with the arbuscular mycorrhizal fungus Funneliformis mosseae (syn. Glomus mosseae) were studied. Phosphate is taken up from the environment by the PHT1 family of plant phosphate transporters, which have been well characterized in several plant species. Bioinformatic analysis identified 12 members of the PHT1 gene family (SiPHT1;1-1;12) in S. italica, and RT and qPCR analysis showed that most of these transporters displayed specific expression patterns with respect to tissue, phosphate status and arbuscular mycorrhizal colonisation. SiPHT1;2 was found to be expressed in all tissues and in all growth conditions tested. In contrast, expression of SiPHT1;4 was induced in roots after 15 days growth in hydroponic medium of low Pi concentration. Expression of SiPHT1;8 and SiPHT1;9 in roots was selectively induced by colonisation with F. mosseae. SiPHT1;3 and SiPHT1;4 were found to be predominantly expressed in leaf and root tissues respectively. Several other transporters were expressed in shoots and leaves during growth in low Pi concentrations. This study will form the basis for the further characterization of these transporters, with the long term goal of improving the phosphate use efficiency of foxtail millet. PMID:25251671

  6. The languages of parasite communication.

    PubMed

    Roditi, Isabel

    2016-07-01

    Although it is regarded as self-evident that parasites interact with their hosts, with the primary aim of enhancing their own survival and transmission, the extent to which unicellular parasites communicate with each has been severely underestimated. Recent publications show that information is commonly exchanged between parasites of the same species and that this can govern their decisions to divide, to differentiate or to migrate as a group. Communication can take the form of soluble secreted factors, extracellular vesicles or contact between cells. Extracellular parasites can do this directly, while intracellular parasites use the infected host cell - or components derived from it - as an intermediary. By emitting signals that can be dispersed within the host, parasites can also have long-distance effects on the course of an infection and its pathology. This article presents an overview of recent developments in this field and draws attention to some older work that merits re-examination. PMID:27211242

  7. Parasitic Diseases With Cutaneous Manifestations.

    PubMed

    Ash, Mark M; Phillips, Charles M

    2016-01-01

    Parasitic diseases result in a significant global health burden. While often thought to be isolated to returning travelers, parasitic diseases can also be acquired locally in the United States. Therefore, clinicians must be aware of the cutaneous manifestations of parasitic diseases to allow for prompt recognition, effective management, and subsequent mitigation of complications. This commentary also reviews pharmacologic treatment options for several common diseases. PMID:27621348

  8. [Emerging parasitic diseases].

    PubMed

    Weibel Galluzzo, C; Wagner, N; Michel, Y; Jackson, Y; Chappuis, F

    2014-05-01

    Travels, migration and circulation of goods facilitate the emergence of new infectious diseases often unrecognized outside endemic areas. Most of emerging infections are of viral origin. Muscular Sarcocystis infection, an acute illness acquired during short trips to Malaysia, and Chagas disease, a chronic illness with long incubation period found among Latin American migrants, are two very different examples of emerging parasitic diseases. The former requires a preventive approach for travelers going to Malaysia and must be brought forth when they return with fever, myalgia and eosinophilia, while the latter requires a proactive attitude to screen Latin American migrant populations that may face difficulties in accessing care. PMID:24908745

  9. [Parasitic dead-end: update].

    PubMed

    Magnaval, J F

    2006-08-01

    Parasitic dead-ends occur when a parasite is unable to establish a permanent interaction in an unnatural host. Although the likelihood of successful reproduction by the pathogenic agent is nul, parasitic dead-end heralds capture of new parasites and therefore expansion of the host range. Angiostrongyliasis due to A. cantonensis or A. costaricensis, anisakiasis, Ancylostoma caninum infection, gnathostomiasis and sparganosis are undoubtedly emerging zoonoses of particular medical interest. Prevention of these diseases relies on abstinence from eating raw meat from invertebrates or cold-blooded (poikilotherm) vertebrates (e.g. used in exotic dishes). These guidelines must be included in recommendations to travelers. PMID:16999036

  10. Imported parasitic infections in Serbia

    PubMed Central

    Dakić, Z.; Nikolić, A.; Lavadinović, L.; Pelemiš, M.; Klun, I.; Dulović, O.; Milošević, B.; Stevanović, G.; Ofori-Belić, I.; Poluga, J.; Pavlović, M.

    2011-01-01

    Background Travel to the tropics is associated with a risk of parasitic infection, which is increasing in parallel with the rise in travel to these areas. We thus examined the prevalence and trend in the occurrence of parasitic infections in Serbian travelers. Methods A retrospective analysis of the medical records of all travelers returning from tropical and subtropical areas, who presented at the Institute for Infectious and Tropical Diseases in Belgrade between January 2001 and January 2008, was performed. Results Of a total of 2440 travelers, 169 (6.9%) were diagnosed with a parasitic infection, including malaria in 79, intestinal parasites in 84 (pathogenic species in 30 and non-pathogenic in 54), filariasis in four, and visceral leishmaniasis and fascioliasis in one patient each. Importantly, of the whole series only 583 (23.9%) were symptomatic, of which 19.4% were found to be infected with a parasite. The single pathogenic parasite occurring in asymptomatic patients was Giardia intestinalis. Conclusions Parasitic infection causing symptomatic disease among travelers returning from tropical areas to Serbia is not infrequent. In view of the expected increase in travel to the tropics, diagnostic protocols for tropical parasitic diseases should take these data into account. PMID:24466436

  11. NLR proteins and parasitic disease.

    PubMed

    Clay, Gwendolyn M; Sutterwala, Fayyaz S; Wilson, Mary E

    2014-08-01

    Parasitic diseases are a serious global health concern. Many of the most common and most severe parasitic diseases, including Chagas' disease, leishmaniasis, and schistosomiasis, are also classified as neglected tropical diseases and are comparatively less studied than infectious diseases prevalent in high income nations. The NLRs (nucleotide-binding domain leucine-rich-repeat-containing proteins) are cytosolic proteins known to be involved in pathogen detection and host response. The role of NLRs in the host response to parasitic infection is just beginning to be understood. The NLR proteins NOD1 and NOD2 have been shown to contribute to immune responses during Trypanosoma cruzi infection, Toxoplasma gondii infection, and murine cerebral malaria. The NLRP3 inflammasome is activated by T. cruzi and Leishmania amazonensis but also induces pathology during infection with schistosomes or malaria. Both the NLRP1 and NLRP3 inflammasomes respond to T. gondii infection. The NLRs may play crucial roles in human immune responses during parasitic infection, usually acting as innate immune sensors and driving the inflammatory response against invading parasites. However, this inflammatory response can either kill the invading parasite or be responsible for destructive pathology. Therefore, understanding the role of the NLR proteins will be critical to understanding the host defense against parasites as well as the fine balance between homeostasis and parasitic disease. PMID:24989828

  12. Extracellular vesicles in parasitic diseases

    PubMed Central

    Marcilla, Antonio; Martin-Jaular, Lorena; Trelis, Maria; de Menezes-Neto, Armando; Osuna, Antonio; Bernal, Dolores; Fernandez-Becerra, Carmen; Almeida, Igor C.; del Portillo, Hernando A.

    2014-01-01

    Parasitic diseases affect billions of people and are considered a major public health issue. Close to 400 species are estimated to parasitize humans, of which around 90 are responsible for great clinical burden and mortality rates. Unfortunately, they are largely neglected as they are mainly endemic to poor regions. Of relevance to this review, there is accumulating evidence of the release of extracellular vesicles (EVs) in parasitic diseases, acting both in parasite–parasite inter-communication as well as in parasite–host interactions. EVs participate in the dissemination of the pathogen and play a role in the regulation of the host immune systems. Production of EVs from parasites or parasitized cells has been described for a number of parasitic infections. In this review, we provide the most relevant findings of the involvement of EVs in intercellular communication, modulation of immune responses, involvement in pathology, and their potential as new diagnostic tools and therapeutic agents in some of the major human parasitic pathogens. PMID:25536932

  13. Parasitic Weeds, a Scientific Challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent issue of the SCI journal Pest Management Science (May, 2009) was devoted to an overview of the problem of parasitic weeds and to the research that is being done to alleviate it. These papers are from an OECD-sponsored conference entitled Managing Parasitic Weeds that recently brought the b...

  14. Serine proteases of parasitic helminths.

    PubMed

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

    2015-02-01

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

  15. Serine Proteases of Parasitic Helminths

    PubMed Central

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

    2015-01-01

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

  16. Navigating parasite webs and parasite flow: emerging and re-emerging parasitic zoonoses of wildlife origin.

    PubMed

    Polley, Lydden

    2005-10-01

    Wildlife are now recognised as an important source of emerging human pathogens, including parasites. This paper discusses the linkages between wildlife, people, zoonotic parasites and the ecosystems in which they co-exist, revisits definitions for 'emerging' and 're-emerging', and lists zoonotic parasites that can be acquired from wildlife including, for some, estimates of the associated global human health burdens. The paper also introduces the concepts of 'parasite webs' and 'parasite flow', provides a context for parasites, relative to other infectious agents, as causes of emerging human disease, and discusses drivers of disease emergence and re-emergence, especially changes in biodiversity and climate. Angiostrongylus cantonensis in the Caribbean and the southern United States, Baylisascaris procyonis in California and Georgia, Plasmodium knowlesi in Sarawak, Malaysia, Human African Trypanosomiasis, Sarcoptes scabiei in carnivores, and Cryptosporidium, Giardia and Toxoplasma in marine ecosystems are presented as examples of wildlife-derived zoonotic parasites of particular recent interest. An ecological approach to disease is promoted, as is a need for an increased profile for this approach in undergraduate and graduate education in the health sciences. Synergy among scientists and disciplines is identified as critical for the study of parasites and parasitic disease in wildlife populations. Recent advances in techniques for the investigation of parasite fauna of wildlife are presented and monitoring and surveillance systems for wildlife disease are discussed. Some of the limitations inherent in predictions for the emergence and re-emergence of infection and disease associated with zoonotic parasites of wildlife are identified. The importance of public awareness and public education in the prevention and control of emerging and re-emerging zoonotic infection and disease are emphasised. Finally, some thoughts for the future are presented. PMID:16168994

  17. How have fisheries affected parasite communities?

    USGS Publications Warehouse

    Wood, Chelsea L.; Lafferty, Kevin D.

    2015-01-01

    To understand how fisheries affect parasites, we conducted a meta-analysis of studies that contrasted parasite assemblages in fished and unfished areas. Parasite diversity was lower in hosts from fished areas. Larger hosts had a greater abundance of parasites, suggesting that fishing might reduce the abundance of parasites by selectively removing the largest, most heavily parasitized individuals. After controlling for size, the effect of fishing on parasite abundance varied according to whether the host was fished and the parasite's life cycle. Parasites of unfished hosts were more likely to increase in abundance in response to fishing than were parasites of fished hosts, possibly due to compensatory increases in the abundance of unfished hosts. While complex life cycle parasites tended to decline in abundance in response to fishing, directly transmitted parasites tended to increase. Among complex life cycle parasites, those with fished hosts tended to decline in abundance in response to fishing, while those with unfished hosts tended to increase. However, among directly transmitted parasites, responses did not differ between parasites with and without fished hosts. This work suggests that parasite assemblages are likely to change substantially in composition in increasingly fished ecosystems, and that parasite life history and fishing status of the host are important in predicting the response of individual parasite species or groups to fishing.

  18. Cardiac Involvement with Parasitic Infections

    PubMed Central

    Hidron, Alicia; Vogenthaler, Nicholas; Santos-Preciado, José I.; Rodriguez-Morales, Alfonso J.; Franco-Paredes, Carlos; Rassi, Anis

    2010-01-01

    Summary: Parasitic infections previously seen only in developing tropical settings can be currently diagnosed worldwide due to travel and population migration. Some parasites may directly or indirectly affect various anatomical structures of the heart, with infections manifested as myocarditis, pericarditis, pancarditis, or pulmonary hypertension. Thus, it has become quite relevant for clinicians in developed settings to consider parasitic infections in the differential diagnosis of myocardial and pericardial disease anywhere around the globe. Chagas' disease is by far the most important parasitic infection of the heart and one that it is currently considered a global parasitic infection due to the growing migration of populations from areas where these infections are highly endemic to settings where they are not endemic. Current advances in the treatment of African trypanosomiasis offer hope to prevent not only the neurological complications but also the frequently identified cardiac manifestations of this life-threatening parasitic infection. The lack of effective vaccines, optimal chemoprophylaxis, or evidence-based pharmacological therapies to control many of the parasitic diseases of the heart, in particular Chagas' disease, makes this disease one of the most important public health challenges of our time. PMID:20375355

  19. Parasites in algae mass culture

    PubMed Central

    Carney, Laura T.; Lane, Todd W.

    2014-01-01

    Parasites are now known to be ubiquitous across biological systems and can play an important role in modulating algal populations. However, there is a lack of extensive information on their role in artificial ecosystems such as algal production ponds and photobioreactors. Parasites have been implicated in the demise of algal blooms. Because individual mass culture systems often tend to be unialgal and a select few algal species are in wide scale application, there is an increased potential for parasites to have a devastating effect on commercial scale monoculture. As commercial algal production continues to expand with a widening variety of applications, including biofuel, food and pharmaceuticals, the parasites associated with algae will become of greater interest and potential economic impact. A number of important algal parasites have been identified in algal mass culture systems in the last few years and this number is sure to grow as the number of commercial algae ventures increases. Here, we review the research that has identified and characterized parasites infecting mass cultivated algae, the techniques being proposed and or developed to control them, and the potential impact of parasites on the future of the algal biomass industry. PMID:24936200

  20. Diversity of parasite complex II.

    PubMed

    Harada, Shigeharu; Inaoka, Daniel Ken; Ohmori, Junko; Kita, Kiyoshi

    2013-05-01

    Parasites have developed a variety of physiological functions necessary for completing at least part of their life cycles in the specialized environments of surrounding the parasites in the host. Regarding energy metabolism, which is essential for survival, parasites adapt to the low oxygen environment in mammalian hosts by using metabolic systems that are very different from those of the hosts. In many cases, the parasite employs aerobic metabolism during the free-living stage outside the host but undergoes major changes in developmental control and environmental adaptation to switch to anaerobic energy metabolism. Parasite mitochondria play diverse roles in their energy metabolism, and in recent studies of the parasitic nematode, Ascaris suum, the mitochondrial complex II plays an important role in anaerobic energy metabolism of parasites inhabiting hosts by acting as a quinol-fumarate reductase. In Trypanosomes, parasite complex II has been found to have a novel function and structure. Complex II of Trypanosoma cruzi is an unusual supramolecular complex with a heterodimeric iron-sulfur subunit and seven additional non-catalytic subunits. The enzyme shows reduced binding affinities for both substrates and inhibitors. Interestingly, this structural organization is conserved in all trypanosomatids. Since the properties of complex II differ across a wide range of parasites, this complex is a potential target for the development of new chemotherapeutic agents. In this regard, structural information on the target enzyme is essential for the molecular design of drugs. This article is part of a Special Issue entitled: Respiratory complex II: Role in cellular physiology and disease. PMID:23333273

  1. Glomerulopathy Associated with Parasitic Infections

    PubMed Central

    van Velthuysen, M.-L. F.; Florquin, S.

    2000-01-01

    Although parasitic infections do not usually present with disturbance in renal function, glomerular lesions can be seen in most of these infections. The glomerular lesions observed in parasitic infections cover the whole range of glomerular lesions known, but most of them are proliferative. Little is known of the exact pathogenic mechanisms. In this review, we try to explain the glomerular lesions associated with parasitic infections in terms of the specific immunologic events observed during these diseases against the background of recent developments in the general knowledge of the pathogenesis of glomerular disease. PMID:10627491

  2. Parasites in pet reptiles

    PubMed Central

    2011-01-01

    Exotic reptiles originating from the wild can be carriers of many different pathogens and some of them can infect humans. Reptiles imported into Slovenia from 2000 to 2005, specimens of native species taken from the wild and captive bred species were investigated. A total of 949 reptiles (55 snakes, 331 lizards and 563 turtles), belonging to 68 different species, were examined for the presence of endoparasites and ectoparasites. Twelve different groups (Nematoda (5), Trematoda (1), Acanthocephala (1), Pentastomida (1) and Protozoa (4)) of endoparasites were determined in 26 (47.3%) of 55 examined snakes. In snakes two different species of ectoparasites were also found. Among the tested lizards eighteen different groups (Nematoda (8), Cestoda (1), Trematoda (1), Acanthocephala (1), Pentastomida (1) and Protozoa (6)) of endoparasites in 252 (76.1%) of 331 examined animals were found. One Trombiculid ectoparasite was determined. In 563 of examined turtles eight different groups (Nematoda (4), Cestoda (1), Trematoda (1) and Protozoa (2)) of endoparasites were determined in 498 (88.5%) animals. In examined turtles three different species of ectoparasites were seen. The established prevalence of various parasites in reptiles used as pet animals indicates the need for examination on specific pathogens prior to introduction to owners. PMID:21624124

  3. Myxozoan parasitism in waterfowl.

    PubMed

    Bartholomew, Jerri L; Atkinson, Stephen D; Hallett, Sascha L; Lowenstine, Linda J; Garner, Michael M; Gardiner, Chris H; Rideout, Bruce A; Keel, M Kevin; Brown, Justin D

    2008-08-01

    Myxozoans are spore-forming, metazoan parasites common in cold-blooded aquatic vertebrates, especially fishes, with alternate life cycle stages developing in invertebrates. We report nine cases of infection in free-flying native and captive exotic ducks (Anseriformes: Anatidae) from locations across the United States and describe the first myxozoan in birds, Myxidium anatidum n. sp. We found developmental stages and mature spores in the bile ducts of a Pekin duck (domesticated Anas platyrhynchos). Spores are lens-shaped in sutural view, slightly sigmoidal in valvular view, with two polar capsules, and each valve cell has 14-16 longitudinal surface ridges. Spore dimensions are 23.1 microm x 10.8 microm x 11.2 microm. Phylogenetic analysis of the ssrRNA gene revealed closest affinity with Myxidium species described from chelonids (tortoises). Our novel finding broadens the definition of the Myxozoa to include birds as hosts and has implications for understanding myxozoan evolution, and mechanisms of geographical and host range extension. The number of infection records indicates this is not an incidental occurrence, and the detection of such widely dispersed cases suggests more myxozoans in birds will be encountered with increased surveillance of these hosts for pathogens. PMID:18342316

  4. Zoology: Invertebrates that Parasitize Invertebrates.

    PubMed

    Giribet, Gonzalo

    2016-07-11

    The genome of an orthonectid, a group of highly modified parasitic invertebrates, is drastically reduced and compact, yet it shows the bilaterian gene toolkit. Phylogenetic analyses place the enigmatic orthonectids within Spiralia, although their exact placement remains uncertain. PMID:27404242

  5. Climate change and Arctic parasites.

    PubMed

    Dobson, Andy; Molnár, Péter K; Kutz, Susan

    2015-05-01

    Climate is changing rapidly in the Arctic. This has important implications for parasites of Arctic ungulates, and hence for the welfare of Arctic peoples who depend on caribou, reindeer, and muskoxen for food, income, and a focus for cultural activities. In this Opinion article we briefly review recent work on the development of predictive models for the impacts of climate change on helminth parasites and other pathogens of Arctic wildlife, in the hope that such models may eventually allow proactive mitigation and conservation strategies. We describe models that have been developed using the metabolic theory of ecology. The main strength of these models is that they can be easily parameterized using basic information about the physical size of the parasite. Initial results suggest they provide important new insights that are likely to generalize to a range of host-parasite systems. PMID:25900882

  6. Vaccination against helminth parasite infections.

    PubMed

    Hewitson, James P; Maizels, Rick M

    2014-04-01

    Helminth parasites infect over one fourth of the human population and are highly prevalent in livestock worldwide. In model systems, parasites are strongly immunomodulatory, but the immune system can be driven to expel them by prior vaccination. However, no vaccines are currently available for human use. Recent advances in vaccination with recombinant helminth antigens have been successful against cestode infections of livestock and new vaccines are being tested against nematode parasites of animals. Numerous vaccine antigens are being defined for a wide range of helminth parasite species, but greater understanding is needed to define the mechanisms of vaccine-induced immunity, to lay a rational platform for new vaccines and their optimal design. With human trials underway for hookworm and schistosomiasis vaccines, a greater integration between veterinary and human studies will highlight the common molecular and mechanistic pathways, and accelerate progress towards reducing the global health burden of helminth infection. PMID:24606541

  7. Atypical parasitic ischiopagus conjoined twins.

    PubMed

    Corona-Rivera, J Román; Corona-Rivera, Enrique; Franco-Topete, Ramón; Acosta-León, Jorge; Aguila-Dueñas, Virginia; Corona-Rivera, Alfredo

    2003-02-01

    Occurrence of asymmetrical or parasitic conjoined twins (CT) is rare, and currently they are classified analogically to the common unions of symmetrical CT. The authors report on an infant with a parasitic third limb attached to the left lateral aspect of the autosite trunk, in whom male gonadal tissue was found histologically. Parasite parts included complete left lower limb, hemipelvis, lumbosacral vertebral column, spinal cord, and one kidney with ureter and adrenal gland. Autosite anomalies comprised a small left diaphragmatic defect, omphalocele, exstrophy of cloaca, and lumbar meningomyelocele. The authors considered this case to be a rare atypical parasitic ischiopagus CT. The differential diagnosis of the type of twining and other entities with caudal duplications is analyzed briefly. PMID:12596123

  8. Pervasiveness of Parasites in Pollinators

    PubMed Central

    Evison, Sophie E. F.; Roberts, Katherine E.; Laurenson, Lynn; Pietravalle, Stéphane; Hui, Jeffrey; Biesmeijer, Jacobus C.; Smith, Judith E.; Budge, Giles; Hughes, William O. H.

    2012-01-01

    Many pollinator populations are declining, with large economic and ecological implications. Parasites are known to be an important factor in the some of the population declines of honey bees and bumblebees, but little is known about the parasites afflicting most other pollinators, or the extent of interspecific transmission or vectoring of parasites. Here we carry out a preliminary screening of pollinators (honey bees, five species of bumblebee, three species of wasp, four species of hoverfly and three genera of other bees) in the UK for parasites. We used molecular methods to screen for six honey bee viruses, Ascosphaera fungi, Microsporidia, and Wolbachia intracellular bacteria. We aimed simply to detect the presence of the parasites, encompassing vectoring as well as actual infections. Many pollinators of all types were positive for Ascosphaera fungi, while Microsporidia were rarer, being most frequently found in bumblebees. We also detected that most pollinators were positive for Wolbachia, most probably indicating infection with this intracellular symbiont, and raising the possibility that it may be an important factor in influencing host sex ratios or fitness in a diversity of pollinators. Importantly, we found that about a third of bumblebees (Bombus pascuorum and Bombus terrestris) and a third of wasps (Vespula vulgaris), as well as all honey bees, were positive for deformed wing virus, but that this virus was not present in other pollinators. Deformed wing virus therefore does not appear to be a general parasite of pollinators, but does interact significantly with at least three species of bumblebee and wasp. Further work is needed to establish the identity of some of the parasites, their spatiotemporal variation, and whether they are infecting the various pollinator species or being vectored. However, these results provide a first insight into the diversity, and potential exchange, of parasites in pollinator communities. PMID:22347356

  9. Carbohydrate metabolism of malarial parasites

    PubMed Central

    Homewood, C. A.

    1977-01-01

    The evidence for the pathways involved in the metabolism of carbohydrates by malarial parasites is critically reviewed. In all species studied, glucose is catabolized mainly by glycolysis with little participation of the pentose—phosphate pathway. It has not been proved conclusively that there is a functioning citric acid cycle in the intraerythrocytic stages of avian plasmodia, nor is it certain that these stages of any malarial parasites use oxygen. PMID:338181

  10. Molecular diagnostics and parasitic disease.

    PubMed

    Vasoo, Shawn; Pritt, Bobbi S

    2013-09-01

    Molecular parasitology represents an emerging field in microbiology diagnostics. Although most assays use nonstandardized, laboratory-developed methods, a few commercial systems have recently become available and are slowly being introduced into larger laboratories. In addition, a few methodologies show promise for use in field settings in which parasitic infections are endemic. This article reviews the available techniques and their applications to major parasitic diseases such as malaria, leishmaniasis, and trichomoniasis. PMID:23931835

  11. Parasitic Effects on Memristor Dynamics

    NASA Astrophysics Data System (ADS)

    Itoh, Makoto; Chua, Leon O.

    2016-06-01

    In this paper, we show that parasitic elements have a significant effect on the dynamics of memristor circuits. We first show that certain 2-terminal elements such as memristors, memcapacitors, and meminductors can be used as nonvolatile memories, if the principle of conservation of state variables hold by open-circuiting, or short-circuiting, their terminals. We also show that a passive memristor with a strictly-increasing constitutive relation will eventually lose its stored flux when we switch off the power if there is a parasitic capacitance across the memristor. Similarly, a memcapacitor (resp., meminductor) with a positive memcapacitance (resp., meminductance) will eventually lose their stored physical states when we switch off the power, if it is connected to a parasitic resistance. We then show that the discontinuous jump that circuit engineers assumed to occur at impasse points of memristor circuits contradicts the principles of conservation of charge and flux at the time of the discontinuous jump. A parasitic element can be used to break an impasse point, resulting in the emergence of a continuous oscillation in the circuit. We also define a distance, a diameter, and a dimension, for each circuit element in order to measure the complexity order of the parasitic elements. They can be used to find higher-order parasitic elements which can break impasse points. Furthermore, we derived a memristor-based Chua’s circuit from a three-element circuit containing a memristor by connecting two parasitic memcapacitances to break the impasse points. We finally show that a higher-order parasitic element can be used for breaking the impasse points on two-dimensional and three-dimensional constrained spaces.

  12. Pervasiveness of parasites in pollinators.

    PubMed

    Evison, Sophie E F; Roberts, Katherine E; Laurenson, Lynn; Pietravalle, Stéphane; Hui, Jeffrey; Biesmeijer, Jacobus C; Smith, Judith E; Budge, Giles; Hughes, William O H

    2012-01-01

    Many pollinator populations are declining, with large economic and ecological implications. Parasites are known to be an important factor in the some of the population declines of honey bees and bumblebees, but little is known about the parasites afflicting most other pollinators, or the extent of interspecific transmission or vectoring of parasites. Here we carry out a preliminary screening of pollinators (honey bees, five species of bumblebee, three species of wasp, four species of hoverfly and three genera of other bees) in the UK for parasites. We used molecular methods to screen for six honey bee viruses, Ascosphaera fungi, Microsporidia, and Wolbachia intracellular bacteria. We aimed simply to detect the presence of the parasites, encompassing vectoring as well as actual infections. Many pollinators of all types were positive for Ascosphaera fungi, while Microsporidia were rarer, being most frequently found in bumblebees. We also detected that most pollinators were positive for Wolbachia, most probably indicating infection with this intracellular symbiont, and raising the possibility that it may be an important factor in influencing host sex ratios or fitness in a diversity of pollinators. Importantly, we found that about a third of bumblebees (Bombus pascuorum and Bombus terrestris) and a third of wasps (Vespula vulgaris), as well as all honey bees, were positive for deformed wing virus, but that this virus was not present in other pollinators. Deformed wing virus therefore does not appear to be a general parasite of pollinators, but does interact significantly with at least three species of bumblebee and wasp. Further work is needed to establish the identity of some of the parasites, their spatiotemporal variation, and whether they are infecting the various pollinator species or being vectored. However, these results provide a first insight into the diversity, and potential exchange, of parasites in pollinator communities. PMID:22347356

  13. Lipids and the malarial parasite*

    PubMed Central

    Holz, George G.

    1977-01-01

    Merozoite endocytosis initiates Plasmodium development in a vacuole bounded by an erythrocyte-derived membrane, whose asymmetrical distribution of lipids and proteins is reversed in its orientation with respect to the parasite plasma membrane. Reorientation may accompany the proliferation of the membrane associated with the parasite's growth and phagocytic and pinocytic feeding. Increases in the membrane surface area of the parasite, and in some cases of the erythrocyte, parallel parasite growth and segmentation. Augmentation of all the membrane systems of the infected erythrocyte causes the lipid content to rise rapidly, but the parasite lipid composition differs from that of the erythrocyte in many respects: it is higher in diacyl phosphatidylethanolamine, phosphatidylinositol, polyglycerol phosphatides, diacylglycerols, unesterified fatty acids, triacylglycerols, and hexadecanoic and octadecenoic fatty acids and lower in sphingomyelin, phosphatidylserine, alkoxy phosphatidylethanolamine, cholesterol, and polyunsaturated fatty acids. Active lipid metabolism accompanies the membrane proliferation associated with feeding, growth, and reproduction. Plasmodium is incapable of de novo biosynthesis of fatty acids and cholesterol; however, it can fabricate its glycerides and phosphoglycerides with host-supplied fatty acids, nitrogenous bases, alcohols, ATP, and coenzyme A, and can generate the glyceryl moiety during glycolysis. Cholesterol is obtained from the host but nothing is known of sphingolipid origins. Lipid metabolism of the parasite may be associated with alterations in the amounts of octadecenoic fatty acids and cholesterol in the erythrocyte plasma membrane, which in turn are responsible for changes in permeability and fragility. PMID:412602

  14. Parasitic Pneumonia and Lung Involvement

    PubMed Central

    Cheepsattayakorn, Ruangrong

    2014-01-01

    Parasitic infestations demonstrated a decline in the past decade as a result of better hygiene practices and improved socioeconomic conditions. Nevertheless, global immigration, increased numbers of the immunocompromised people, international traveling, global warming, and rapid urbanization of the cities have increased the susceptibility of the world population to parasitic diseases. A number of new human parasites, such as Plasmodium knowlesi, in addition to many potential parasites, have urged the interest of scientific community. A broad spectrum of protozoal parasites frequently affects the respiratory system, particularly the lungs. The diagnosis of parasitic diseases of airway is challenging due to their wide varieties of clinical and roentgenographic presentations. So detailed interrogations of travel history to endemic areas are critical for clinicians or pulmonologists to manage this entity. The migrating adult worms can cause mechanical airway obstruction, while the larvae can cause airway inflammation. This paper provides a comprehensive review of both protozoal and helminthic infestations that affect the airway system, particularly the lungs, including clinical and roentgenographic presentations, diagnostic tests, and therapeutic approaches. PMID:24995332

  15. Birds are islands for parasites

    PubMed Central

    Koop, Jennifer A. H.; DeMatteo, Karen E.; Parker, Patricia G.; Whiteman, Noah K.

    2014-01-01

    Understanding the mechanisms driving the extraordinary diversification of parasites is a major challenge in evolutionary biology. Co-speciation, one proposed mechanism that could contribute to this diversity is hypothesized to result from allopatric co-divergence of host–parasite populations. We found that island populations of the Galápagos hawk (Buteo galapagoensis) and a parasitic feather louse species (Degeeriella regalis) exhibit patterns of co-divergence across variable temporal and spatial scales. Hawks and lice showed nearly identical population genetic structure across the Galápagos Islands. Hawk population genetic structure is explained by isolation by distance among islands. Louse population structure is best explained by hawk population structure, rather than isolation by distance per se, suggesting that lice tightly track the recent population histories of their hosts. Among hawk individuals, louse populations were also highly structured, suggesting that hosts serve as islands for parasites from an evolutionary perspective. Altogether, we found that host and parasite populations may have responded in the same manner to geographical isolation across spatial scales. Allopatric co-divergence is likely one important mechanism driving the diversification of parasites. PMID:25099959

  16. Birds are islands for parasites.

    PubMed

    Koop, Jennifer A H; DeMatteo, Karen E; Parker, Patricia G; Whiteman, Noah K

    2014-08-01

    Understanding the mechanisms driving the extraordinary diversification of parasites is a major challenge in evolutionary biology. Co-speciation, one proposed mechanism that could contribute to this diversity is hypothesized to result from allopatric co-divergence of host-parasite populations. We found that island populations of the Galápagos hawk (Buteo galapagoensis) and a parasitic feather louse species (Degeeriella regalis) exhibit patterns of co-divergence across variable temporal and spatial scales. Hawks and lice showed nearly identical population genetic structure across the Galápagos Islands. Hawk population genetic structure is explained by isolation by distance among islands. Louse population structure is best explained by hawk population structure, rather than isolation by distance per se, suggesting that lice tightly track the recent population histories of their hosts. Among hawk individuals, louse populations were also highly structured, suggesting that hosts serve as islands for parasites from an evolutionary perspective. Altogether, we found that host and parasite populations may have responded in the same manner to geographical isolation across spatial scales. Allopatric co-divergence is likely one important mechanism driving the diversification of parasites. PMID:25099959

  17. Hosts and parasites as aliens.

    PubMed

    Taraschewski, H

    2006-06-01

    Over the past decades, various free-living animals (hosts) and their parasites have invaded recipient areas in which they had not previously occurred, thus gaining the status of aliens or exotics. In general this happened to a low extent for hundreds of years. With variable frequency, invasions have been followed by the dispersal and establishment of non-indigenous species, whether host or parasite. In the literature thus far, colonizations by both hosts and parasites have not been treated and reviewed together, although both are usually interwoven in various ways. As to those factors permitting invasive success and colonization strength, various hypotheses have been put forward depending on the scientific background of respective authors and on the conspicuousness of certain invasions. Researchers who have tried to analyse characteristic developmental patterns, the speed of dispersal or the degree of genetic divergence in populations of alien species have come to different conclusions. Among parasitologists, the applied aspects of parasite invasions, such as the negative effects on economically important hosts, have long been at the centre of interest. In this contribution, invasions by hosts as well as parasites are considered comparatively, revealing many similarities and a few differences. Two helminths, the liver fluke, Fasciola hepatica, of cattle and sheep and the swimbladder nematode, Anguillicola crassus, of eels are shown to be useful as model parasites for the study of animal invasions and environmental global change. Introductions of F. hepatica have been associated with imports of cattle or other grazing animals. In various target areas, susceptible lymnaeid snails serving as intermediate hosts were either naturally present and/or were introduced from the donor continent of the parasite (Europe) and/or from other regions which were not within the original range of the parasite, partly reflecting progressive stages of a global biota change. In several

  18. Parasitic polymorphism of Coccidioides spp

    PubMed Central

    2014-01-01

    Background Coccidioides spp. is the ethiological agent of coccidioidomycosis, an infection that can be fatal. Its diagnosis is complicated, due to that it shares clinical and histopathological characteristics with other pulmonary mycoses. Coccidioides spp. is a dimorphic fungus and, in its saprobic phase, grows as a mycelium, forming a large amount of arthroconidia. In susceptible persons, arthroconidia induce dimorphic changes into spherules/endospores, a typical parasitic form of Coccidioides spp. In addition, the diversity of mycelial parasitic forms has been observed in clinical specimens; they are scarcely known and produce errors in diagnosis. Methods We presented a retrospective study of images from specimens of smears with 15% potassium hydroxide, cytology, and tissue biopsies of a histopathologic collection from patients with coccidioidomycosis seen at a tertiary-care hospital in Mexico City. Results The parasitic polymorphism of Coccidioides spp. observed in the clinical specimens was as follows: i) spherules/endospores in different maturation stages; ii) pleomorphic cells (septate hyphae, hyphae composed of ovoid and spherical cells, and arthroconidia), and iii) fungal ball formation (mycelia with septate hyphae and arthroconidia). Conclusions The parasitic polymorphism of Coccidioides spp. includes the following: spherules/endospores, arthroconidia, and different forms of mycelia. This knowledge is important for the accurate diagnosis of coccidioidomycosis. In earlier studies, we proposed the integration of this diversity of forms in the Coccidioides spp. parasitic cycle. The microhabitat surrounding the fungus into the host would favor the parasitic polymorphism of this fungus, and this environment may assist in the evolution toward parasitism of Coccidioides spp. PMID:24750998

  19. Host-parasite interactions: Marine bivalve molluscs and protozoan parasites, Perkinsus species.

    PubMed

    Soudant, Philippe; E Chu, Fu-Lin; Volety, Aswani

    2013-10-01

    This review assesses and examines the work conducted to date concerning host and parasite interactions between marine bivalve molluscs and protozoan parasites, belonging to Perkinsus species. The review focuses on two well-studied host-parasite interaction models: the two clam species, Ruditapes philippinarum and R. decussatus, and the parasite Perkinsus olseni, and the eastern oyster, Crassostrea virginica, and the parasite Perkinsus marinus. Cellular and humoral defense responses of the host in combating parasitic infection, the mechanisms (e.g., antioxidant enzymes, extracellular products) employed by the parasite in evading host defenses as well as the role of environmental factors in modulating the host-parasite interactions are described. PMID:23871855

  20. Parasites and chronic renal failure

    PubMed Central

    Mohammadi Manesh, Reza; Hosseini Safa, Ahmad; Sharafi, Seyedeh Maryam; Jafari, Rasool; Bahadoran, Mehran; Yousefi, Morteza; Nasri, Hamid; Yousofi Darani, Hossein

    2014-01-01

    Suppression of the human immune system results in an increase in susceptibility to infection by various infectious agents. Conditions such as AIDS, organ transplantation and chronic renal insufficiency (CRI) are the most important cause of insufficient immune response against infections. Long term renal disorders result in uremia, which can suppress human immune system. Parasitic infections are one of the most important factors indicating the public health problems of the societies. These infections can be more hostile and life threatening in susceptible individuals than in the normal people. In these patients some parasitic infections such as blastocystiosis, cryptosporidiosis and toxoplasmosis have been reported to be more prevalent. This review aimed to give an overview about parasitic infections in patients with renal disorders. PMID:25610885

  1. Parasites and immunotherapy: with or against?

    PubMed

    Yousofi Darani, Hossein; Yousefi, Morteza; Safari, Marzieh; Jafari, Rasool

    2016-06-01

    Immunotherapy is a sort of therapy in which antibody or antigen administrates to the patient in order to treat or reduce the severity of complications of disease. This kind of treatment practiced in a wide variety of diseases including infectious diseases, autoimmune disorders, cancers and allergy. Successful and unsuccessful immunotherapeutic strategies have been practiced in variety of parasitic infections. On the other hand parasites or parasite antigens have also been considered for immunotherapy against other diseases such as cancer, asthma and multiple sclerosis. In this paper immunotherapy against common parasitic infections, and also immunotherapy of cancer, asthma and multiple sclerosis with parasites or parasite antigens have been reviewed. PMID:27413282

  2. 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. PMID:26597065

  3. Secretory Pathway of Trypanosomatid Parasites

    PubMed Central

    McConville, Malcolm J.; Mullin, Kylie A.; Ilgoutz, Steven C.; Teasdale, Rohan D.

    2002-01-01

    The Trypanosomatidae comprise a large group of parasitic protozoa, some of which cause important diseases in humans. These include Trypanosoma brucei (the causative agent of African sleeping sickness and nagana in cattle), Trypanosoma cruzi (the causative agent of Chagas' disease in Central and South America), and Leishmania spp. (the causative agent of visceral and [muco]cutaneous leishmaniasis throughout the tropics and subtropics). The cell surfaces of these parasites are covered in complex protein- or carbohydrate-rich coats that are required for parasite survival and infectivity in their respective insect vectors and mammalian hosts. These molecules are assembled in the secretory pathway. Recent advances in the genetic manipulation of these parasites as well as progress with the parasite genome projects has greatly advanced our understanding of processes that underlie secretory transport in trypanosomatids. This article provides an overview of the organization of the trypanosomatid secretory pathway and connections that exist with endocytic organelles and multiple lytic and storage vacuoles. A number of the molecular components that are required for vesicular transport have been identified, as have some of the sorting signals that direct proteins to the cell surface or organelles in the endosome-vacuole system. Finally, the subcellular organization of the major glycosylation pathways in these parasites is reviewed. Studies on these highly divergent eukaryotes provide important insights into the molecular processes underlying secretory transport that arose very early in eukaryotic evolution. They also reveal unusual or novel aspects of secretory transport and protein glycosylation that may be exploited in developing new antiparasite drugs. PMID:11875130

  4. Oncogenic Brain Metazoan Parasite Infection

    PubMed Central

    Spurgeon, Angela N.; Cress, Marshall C.; Gabor, Oroszi; Ding, Qing-Qing; Miller, Douglas C.

    2013-01-01

    Multiple observations suggest that certain parasitic infections can be oncogenic. Among these, neurocysticercosis is associated with increased risk for gliomas and hematologic malignancies. We report the case of a 71-year-old woman with colocalization of a metazoan parasite, possibly cysticercosis, and a WHO grade IV neuroepithelial tumor with exclusively neuronal differentiation by immunohistochemical stains (immunopositive for synaptophysin, neurofilament protein, and Neu-N and not for GFAP, vimentin, or S100). The colocalization and temporal relationship of these two entities suggest a causal relationship. PMID:24151568

  5. Can Parasites Really Reveal Environmental Impact?

    EPA Science Inventory

    This review assesses the usefulness of parasites as bioindicators of environmental impact. Relevant studies published in the past decade were compiled; factorial meta-analysis demonstrated significant effects and interactions between parasite levels and the presence and concentra...

  6. Sacral Rachipagus Parasite: A Case Report.

    PubMed

    Rattan, Kamal Nain; Singh, Jasbir; Dalal, Poonam; Sonika, Pallavi; Rattan, Ananta

    2016-01-01

    We are reporting a case of sacral rachipagus parasite which was vaginally delivered as a large irregular mass attached to the sacral region by a vascular pedicle. This case was managed successfully by surgical excision of parasite. PMID:27123400

  7. Sacral Rachipagus Parasite: A Case Report

    PubMed Central

    Rattan, Kamal Nain; Singh, Jasbir; Dalal, Poonam; Sonika, Pallavi; Rattan, Ananta

    2016-01-01

    We are reporting a case of sacral rachipagus parasite which was vaginally delivered as a large irregular mass attached to the sacral region by a vascular pedicle. This case was managed successfully by surgical excision of parasite. PMID:27123400

  8. Biology Today: Parasites and Human Ecology.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1984-01-01

    Offers various reasons why the study of parasites and the diseases they cause should be incorporated into classroom biology discussions. Examples of several parasitic diseases and their ecological significance are provided. (JN)

  9. Parasitic Diseases - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Are Here: Home → Multiple Languages → All Health Topics → Parasitic Diseases URL of this page: https://medlineplus.gov/languages/ ... V W XYZ List of All Topics All Parasitic Diseases - Multiple Languages To use the sharing features on ...

  10. Rodent sociality and parasite diversity.

    PubMed

    Bordes, Frédéric; Blumstein, Daniel T; Morand, Serge

    2007-12-22

    The risk of parasitism is considered to be a general cost of sociality and individuals living in larger groups are typically considered to be more likely to be infected with parasites. However, contradictory results have been reported for the relationship between group size and infection by directly transmitted parasites. We used independent contrasts to examine the relationship between an index of sociality in rodents and the diversity of their macroparasites (helminths and arthropods such as fleas, ticks, suckling lice and mesostigmatid mites). We found that the species richness of directly transmitted ectoparasites, but not endoparasites, decreased significantly with the level of rodent sociality. A greater homogeneity in the biotic environment (i.e. a reduced number of cohabiting host species) of the more social species may have reduced ectoparasites' diversity by impairing ectoparasites transmission and exchange. Our finding may also result from beneficial outcomes of social living that include behavioural defences, like allogrooming, and the increased avoidance of parasites through dilution effects. PMID:17925270

  11. Emerging parasitic diseases of sheep.

    PubMed

    Taylor, M A

    2012-09-30

    There have been changes in the emergence and inability to control of a number of sheep parasitic infections over the last decade. This review focuses on the more globally important sheep parasites, whose reported changes in epidemiology, occurrence or failure to control are becoming increasingly evident. One of the main perceived driving forces is climate change, which can have profound effects on parasite epidemiology, especially for those parasitic diseases where weather has a direct effect on the development of free-living stages. The emergence of anthelmintic-resistant strains of parasitic nematodes and the increasing reliance placed on anthelmintics for their control, can exert profound changes on the epidemiology of those nematodes causing parasitic gastroenteritis. As a consequence, the effectiveness of existing control strategies presents a major threat to sheep production in many areas around the world. The incidence of the liver fluke, Fasciola hepatica, is inextricably linked to high rainfall and is particularly prevalent in high rainfall years. Over the last few decades, there have also been increasing reports of other fluke associated diseases, such as dicroceliosis and paramphistomosis, in a number of western European countries, possibly introduced through animal movements, and able to establish with changing climates. External parasite infections, such as myiasis, can cause significant economic loss and presents as a major welfare problem. The range of elevated temperatures predicted by current climate change scenarios, result in an elongated blowfly season with earlier spring emergence and a higher cumulative incidence of fly strike. Additionally, legislative decisions leading to enforced changes in pesticide usage and choices have resulted in increased reports and spread of ectoparasitic infections, particularly mite, lice and tick infestations in sheep. Factors, such as dip disposal and associated environmental concerns, and, perhaps more

  12. Parasite control in transhumant situations.

    PubMed

    Eckert, J; Hertzberg, H

    1994-08-01

    Transhumance is defined as 'seasonal moving of livestock to regions of different climate'. It is an integral part of livestock production in many parts of the world and takes several forms including moving of livestock from lowland to mountainous pastures or from dry to humid areas. The impact of transhumance on parasite populations of livestock and on parasite control is described, mainly using examples from Europe. The epidemiology of trichostrongylidosis of cattle, mainly caused by Ostertagia ostertagi and Cooperia oncophora, is characterised by prolonged survival of overwintered infective larvae until the end of June. Cattle moved to such contaminated pastures in a transhumant grazing system are exposed to these larvae and may be protected, during the second half of the grazing season until autumn, by a late application (June/July) of an intraruminal drug-release device. Community pastures used in a transhumant system with mixed grazing of young cattle originating from various farms may enhance transmission of dictyocaulosis. Therefore, specific prophylactic measures are required. Hill sheep nematode populations may differ from those in lowland sheep in that Haemonchus contortus generally plays a minor role in hill sheep in which Ostertagia circumcincta and Nematodirus spp. predominate. Infections with Fasciola hepatica and Dicrocoelium dendriticum can be acquired on mountainous pastures by cattle, sheep and other livestock grazing in a transhumant system as intermediate hosts of these parasites may find suitable habitats in these regions. There is evidence that in the prealpine and alpine area both parasites are mainly transmitted in two-season cycles. Further examples for the impact of transhumance on parasite-host inter-relationships include cysticercosis in cattle, echinococcosis, psoroptic manage in sheep, tick-borne fever of cattle, and hypodermosis in cattle. These are described and discussed. PMID:7846845

  13. Parasitism, host immune function, and sexual selection.

    PubMed

    Møller, A P; Christe, P; Lux, E

    1999-03-01

    Parasite-mediated sexual selection may arise as a consequence of 1) females avoiding mates with directly transmitted parasites, 2) females choosing less-parasitized males that provide parental care of superior quality, or 3) females choosing males with few parasites in order to obtain genes for parasite resistance in their offspring. Studies of specific host-parasite systems and comparative analyses have revealed both supportive and conflicting evidence for these hypotheses. A meta-analysis of the available evidence revealed a negative relationship between parasite load and the expression of male secondary sexual characters. Experimental studies yielded more strongly negative relationships than observations did, and the relationships were more strongly negative for ectoparasites than for endoparasites. There was no significant difference in the magnitude of the negative effect for species with and without male parental care, or between behavioral and morphological secondary sexual characters. There was a significant difference between studies based on host immune function and those based on parasite loads, with stronger effects for measures of immune function, suggesting that the many negative results from previous analyses of parasite-mediated sexual selection may be explained because relatively benign parasites were studied. The multivariate analyses demonstrating strong effect sizes of immune function in relation to the expression of secondary sexual characters, and for species with male parental care as compared to those without, suggest that parasite resistance may be a general determinant of parasite-mediated sexual selection. PMID:10081812

  14. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites,...

  15. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites,...

  16. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites,...

  17. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites,...

  18. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites,...

  19. Postcolonial Ecologies of Parasite and Host: Making Parasitism Cosmopolitan.

    PubMed

    Anderson, Warwick

    2016-04-01

    The interest of F. Macfarlane Burnet in host-parasite interactions grew through the 1920s and 1930s, culminating in his book, Biological Aspects of Infectious Disease (1940), often regarded as the founding text of disease ecology. Our knowledge of the influences on Burnet's ecological thinking is still incomplete. Burnet later attributed much of his conceptual development to his reading of British theoretical biology, especially the work of Julian Huxley and Charles Elton, and regretted he did not study Theobald Smith's Parasitism and Disease (1934) until after he had formulated his ideas. Scholars also have adduced Burnet's fascination with natural history and the clinical and public health demands on his research effort, among other influences. I want to consider here additional contributions to Burnet's ecological thinking, focusing on his intellectual milieu, placing his research in a settler society with exceptional expertise in environmental studies and pest management. In part, an ''ecological turn'' in Australian science in the 1930s, derived to a degree from British colonial scientific investments, shaped Burnet's conceptual development. This raises the question of whether we might characterize, in postcolonial fashion, disease ecology, and other studies of parasitism, as successful settler colonial or dominion science. PMID:27188710

  20. Independent origins of parasitism in Animalia.

    PubMed

    Weinstein, Sara B; Kuris, Armand M

    2016-07-01

    Nearly half of all animals may have a parasitic lifestyle, yet the number of transitions to parasitism and their potential for species diversification remain unresolved. Based on a comprehensive survey of the animal kingdom, we find that parasitism has independently evolved at least 223 times in just 15 phyla, with the majority of identified independent parasitic groups occurring in the Arthropoda, at or below the level of Family. Metazoan parasitology is dominated by the study of helminthes; however, only 20% of independently derived parasite taxa belong to those groups, with numerous transitions also seen in Mollusca, Rotifera, Annelida and Cnidaria. Parasitism is almost entirely absent from deuterostomes, and although worm-like morphology and host associations are widespread across Animalia, the dual symbiotic and trophic interactions required for parasitism may constrain its evolution from antecedent consumer strategies such as generalist predators and filter feeders. In general, parasitic groups do not differ from their free-living relatives in their potential for speciation. However, the 10 largest parasitic clades contain 90% of described parasitic species, or perhaps 40% of all animal species. Hence, a substantial fraction of animal diversity on the Earth arose following these few transitions to a parasitic trophic strategy. PMID:27436119

  1. Allee effect from parasite spill-back.

    PubMed

    Krkošek, Martin; Ashander, Jaime; Frazer, L Neil; Lewis, Mark A

    2013-11-01

    The exchange of native pathogens between wild and domesticated animals can lead to novel disease threats to wildlife. However, the dynamics of wild host-parasite systems exposed to a reservoir of domesticated hosts are not well understood. A simple mathematical model reveals that the spill-back of native parasites from domestic to wild hosts may cause a demographic Allee effect in the wild host population. A second model is tailored to the particulars of pink salmon (Oncorhynchus gorbuscha) and salmon lice (Lepeophtheirus salmonis), for which parasite spill-back is a conservation and fishery concern. In both models, parasite spill-back weakens the coupling of parasite and wild host abundance-particularly at low host abundance-causing parasites per host to increase as a wild host population declines. These findings show that parasites shared across host populations have effects analogous to those of generalist predators and can similarly cause an unstable equilibrium in a focal host population that separates persistence and extirpation. Allee effects in wildlife arising from parasite spill-back are likely to be most pronounced in systems where the magnitude of transmission from domestic to wild host populations is high because of high parasite abundance in domestic hosts, prolonged sympatry of domestic and wild hosts, a high transmission coefficient for parasites, long-lived parasite larvae, and proximity of domesticated populations to wildlife migration corridors. PMID:24107371

  2. Host Sexual Dimorphism and Parasite Adaptation

    PubMed Central

    Duneau, David; Ebert, Dieter

    2012-01-01

    In species with separate sexes, parasite prevalence and disease expression is often different between males and females. This effect has mainly been attributed to sex differences in host traits, such as immune response. Here, we make the case for how properties of the parasites themselves can also matter. Specifically, we suggest that differences between host sexes in many different traits, such as morphology and hormone levels, can impose selection on parasites. This selection can eventually lead to parasite adaptations specific to the host sex more commonly encountered, or to differential expression of parasite traits depending on which host sex they find themselves in. Parasites adapted to the sex of the host in this way can contribute to differences between males and females in disease prevalence and expression. Considering those possibilities can help shed light on host–parasite interactions, and impact epidemiological and medical science. PMID:22389630

  3. [World Collections of Parasitic Worms].

    PubMed

    Zinovieva, S V; Butorina, N N; Udalova, Zh V; Khasanova, S; Filimonova, L V; Petrosyan, V G; Pel'gunov, A N

    2015-01-01

    This article provides information about the depositories of parasitic worms in the scientific institutes and museums in the United States, Japan, and Europe (the total number of samples and the availability of types of helminths from various classes), as well as information on the availability of electronic catalogues of the collections in the continental, national, and regional centers for collective use. The extent of this material has determined the necessity of creating digital collections and libraries that would represent a new form of storing, displaying, and exchanging information for scientific research. An analysis was performed of the current state of approaches and methods of development of the specialized information retrieval system (IRS) and databases (DBs) on the parasitic worms in Russia on the basis of a common conceptual data model, taking into account their local use (as desktop systems of database management) and access by scientists worldwide via the Internet. PMID:26852482

  4. Transfusion-transmitted parasitic infections.

    PubMed

    Singh, Gagandeep; Sehgal, Rakesh

    2010-07-01

    The transmission of parasitic organisms through transfusion is relatively rare. Of the major transfusion-transmitted diseases, malaria is a major cause of TTIP in tropical countries whereas babesiosis and Chagas' disease pose the greatest threat to donors in the USA In both cases, this is due to the increased number of potentially infected donors. There are no reliable serologic tests available to screen donors for any of these organisms and the focus for prevention remains on adherence to donor screening guidelines that address travel history and previous infection with the etiologic agent. One goal is the development of tests that are able to screen for and identify donors potentially infectious for parasitic infections without causing the deferral of a large number of non-infectious donors or significantly increasing costs. Ideally, methods to inactivate the infectious organism will provide an element of added safety to the blood supply. PMID:20859503

  5. Transfusion-transmitted parasitic infections

    PubMed Central

    Singh, Gagandeep; Sehgal, Rakesh

    2010-01-01

    The transmission of parasitic organisms through transfusion is relatively rare. Of the major transfusion-transmitted diseases, malaria is a major cause of TTIP in tropical countries whereas babesiosis and Chagas’ disease pose the greatest threat to donors in the USA In both cases, this is due to the increased number of potentially infected donors. There are no reliable serologic tests available to screen donors for any of these organisms and the focus for prevention remains on adherence to donor screening guidelines that address travel history and previous infection with the etiologic agent. One goal is the development of tests that are able to screen for and identify donors potentially infectious for parasitic infections without causing the deferral of a large number of non-infectious donors or significantly increasing costs. Ideally, methods to inactivate the infectious organism will provide an element of added safety to the blood supply. PMID:20859503

  6. Parasitic diseases and urban development.

    PubMed Central

    Mott, K. E.; Desjeux, P.; Moncayo, A.; Ranque, P.; de Raadt, P.

    1990-01-01

    The distribution and epidemiology of parasitic diseases in both urban and periurban areas of endemic countries have been changing as development progresses. The following different scenarios involving Chagas disease, lymphatic filariasis, leishmaniasis and schistosomiasis are discussed: (1) infected persons entering nonendemic urban areas without vectors; (2) infected persons entering nonendemic urban areas with vectors; (3) infected persons entering endemic urban areas; (4) non-infected persons entering endemic urban areas; (5) urbanization or domestication of natural zoonotic foci; and (6) vectors entering nonendemic urban areas. Cultural and social habits from the rural areas, such as type of house construction and domestic water usage, are adopted by migrants to urban areas and increase the risk of disease transmission which adversely affects employment in urban populations. As the urban health services must deal with the rise in parasitic diseases, appropriate control strategies for the urban setting must be developed and implemented. PMID:2127380

  7. Peritoneal manifestations of parasitic infection.

    PubMed

    Kim, So Yeon; Ha, Hyun Kwon

    2008-01-01

    The purpose of this study was to describe of peritoneal manifestations of parasitic infection at CT. A broad spectrum of CT findings can be seen in the peritoneal cavity, including a varying degree of omental or mesenteric infiltration, single or multiple peritoneal mass or nodule, and peritoneal thickening or stranding. Recognition of these findings are crucial for establish an early diagnosis and helps avoid unnecessary surgery. PMID:17924162

  8. Eosinophilic fasciitis after parasite infection

    PubMed Central

    Patinha, Fabia; Marinho, Antonio

    2016-01-01

    Eosinophilic fasciitis is a systemic inflammatory disease characterized by symmetrical swelling and skin induration of the distal portions of the arms and/or legs, evolving into a scleroderma-like appearance, accompanied by peripheral blood eosinophilia. It is a rare disease with a poorly understood etiology. Corticosteroid treatment remains the standard therapy, either taken alone or in association with an immunosuppressive drug. This paper presents a case of a male patient with palpebral edema and marked eosinophilia, diagnosed with intestinal parasitic infection in October 2006. He was treated with an antiparasitic drug, but both the swelling and the analytical changes remained. This was followed by a skin and muscle biopsy, which turned out to be compatible with eosinophilic fasciitis. There was progressive worsening of the clinical state, with stiffness of the abdominal wall and elevated inflammatory parameters, and the patient was referred to the Immunology Department, medicated with corticosteroids and methotrexate. Over the years there were therapeutic adjustments and other causes were excluded. Currently the patient continues to be monitored, and there is no evidence of active disease. The case described in this article is interesting because of the diagnosis of eosinophilic fasciitis probably associated/coexisting with a parasite infection. This case report differs from others in that there is an uncommon cause associated with the onset of the disease, instead of the common causes such as trauma, medication, non-parasitic infections or cancer. PMID:27407276

  9. Fauna europaea: helminths (animal parasitic).

    PubMed

    Gibson, David I; Bray, Rodney A; Hunt, David; Georgiev, Boyko B; Scholz, Tomaš; Harris, Philip D; Bakke, Tor A; Pojmanska, Teresa; Niewiadomska, Katarzyna; Kostadinova, Aneta; Tkach, Vasyl; Bain, Odile; Durette-Desset, Marie-Claude; Gibbons, Lynda; Moravec, František; Petter, Annie; Dimitrova, Zlatka M; Buchmann, Kurt; Valtonen, E Tellervo; de Jong, Yde

    2014-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. Helminths parasitic in animals represent a large assemblage of worms, representing three phyla, with more than 200 families and almost 4,000 species of parasites from all major vertebrate and many invertebrate groups. A general introduction is given for each of the major groups of parasitic worms, i.e. the Acanthocephala, Monogenea, Trematoda (Aspidogastrea and Digenea), Cestoda and Nematoda. Basic information for each group includes its size, host-range, distribution, morphological features, life-cycle, classification, identification and recent key-works. Tabulations include a complete list of families dealt with, the number of species in each and the name of the specialist responsible for data acquisition, a list of additional specialists who helped with particular groups, and a list of higher taxa dealt with down to the family level. A compilation of useful references is appended. PMID:25349520

  10. Fauna Europaea: Helminths (Animal Parasitic)

    PubMed Central

    Bray, Rodney A.; Hunt, David; Georgiev, Boyko B.; Scholz, Tomaš; Harris, Philip D.; Bakke, Tor A.; Pojmanska, Teresa; Niewiadomska, Katarzyna; Kostadinova, Aneta; Tkach, Vasyl; Bain, Odile; Durette-Desset, Marie-Claude; Gibbons, Lynda; Moravec, František; Petter, Annie; Dimitrova, Zlatka M.; Buchmann, Kurt; Valtonen, E. Tellervo; de Jong, Yde

    2014-01-01

    Abstract Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. Helminths parasitic in animals represent a large assemblage of worms, representing three phyla, with more than 200 families and almost 4,000 species of parasites from all major vertebrate and many invertebrate groups. A general introduction is given for each of the major groups of parasitic worms, i.e. the Acanthocephala, Monogenea, Trematoda (Aspidogastrea and Digenea), Cestoda and Nematoda. Basic information for each group includes its size, host-range, distribution, morphological features, life-cycle, classification, identification and recent key-works. Tabulations include a complete list of families dealt with, the number of species in each and the name of the specialist responsible for data acquisition, a list of additional specialists who helped with particular groups, and a list of higher taxa dealt with down to the family level. A compilation of useful references is appended. PMID:25349520

  11. Eosinophilic fasciitis after parasite infection.

    PubMed

    Oliveira, Marta; Patinha, Fabia; Marinho, Antonio

    2016-01-01

    Eosinophilic fasciitis is a systemic inflammatory disease characterized by symmetrical swelling and skin induration of the distal portions of the arms and/or legs, evolving into a scleroderma-like appearance, accompanied by peripheral blood eosinophilia. It is a rare disease with a poorly understood etiology. Corticosteroid treatment remains the standard therapy, either taken alone or in association with an immunosuppressive drug. This paper presents a case of a male patient with palpebral edema and marked eosinophilia, diagnosed with intestinal parasitic infection in October 2006. He was treated with an antiparasitic drug, but both the swelling and the analytical changes remained. This was followed by a skin and muscle biopsy, which turned out to be compatible with eosinophilic fasciitis. There was progressive worsening of the clinical state, with stiffness of the abdominal wall and elevated inflammatory parameters, and the patient was referred to the Immunology Department, medicated with corticosteroids and methotrexate. Over the years there were therapeutic adjustments and other causes were excluded. Currently the patient continues to be monitored, and there is no evidence of active disease. The case described in this article is interesting because of the diagnosis of eosinophilic fasciitis probably associated/coexisting with a parasite infection. This case report differs from others in that there is an uncommon cause associated with the onset of the disease, instead of the common causes such as trauma, medication, non-parasitic infections or cancer. PMID:27407276

  12. Parasites as prey in aquatic food webs: implications for predator infection and parasite transmission

    USGS Publications Warehouse

    Thieltges, David W.; Amundsen, Per-Arne; Hechinger, Ryan F.; Johnson, Pieter T.J.; Lafferty, Levin D.; Mouritsen, Kim N.; Preston, Daniel L.; Reise, Karsten; Zander, C. Dieter; Poulin, Robert

    2013-01-01

    While the recent inclusion of parasites into food-web studies has highlighted the role of parasites as consumers, there is accumulating evidence that parasites can also serve as prey for predators. Here we investigated empirical patterns of predation on parasites and their relationships with parasite transmission in eight topological food webs representing marine and freshwater ecosystems. Within each food web, we examined links in the typical predator–prey sub web as well as the predator–parasite sub web, i.e. the quadrant of the food web indicating which predators eat parasites. Most predator– parasite links represented ‘concomitant predation’ (consumption and death of a parasite along with the prey/host; 58–72%), followed by ‘trophic transmission’ (predator feeds on infected prey and becomes infected; 8–32%) and predation on free-living parasite life-cycle stages (4–30%). Parasite life-cycle stages had, on average, between 4.2 and 14.2 predators. Among the food webs, as predator richness increased, the number of links exploited by trophically transmitted parasites increased at about the same rate as did the number of links where these stages serve as prey. On the whole, our analyses suggest that predation on parasites has important consequences for both predators and parasites, and food web structure. Because our analysis is solely based on topological webs, determining the strength of these interactions is a promising avenue for future research.

  13. The evolution of parasitism in Nematoda.

    PubMed

    Blaxter, Mark; Koutsovoulos, Georgios

    2015-02-01

    Nematodes are abundant and diverse, and include many parasitic species. Molecular phylogenetic analyses have shown that parasitism of plants and animals has arisen at least 15 times independently. Extant nematode species also display lifestyles that are proposed to be on the evolutionary trajectory to parasitism. Recent advances have permitted the determination of the genomes and transcriptomes of many nematode species. These new data can be used to further resolve the phylogeny of Nematoda, and identify possible genetic patterns associated with parasitism. Plant-parasitic nematode genomes show evidence of horizontal gene transfer from other members of the rhizosphere, and these genes play important roles in the parasite-host interface. Similar horizontal transfer is not evident in animal parasitic groups. Many nematodes have bacterial symbionts that can be essential for survival. Horizontal transfer from symbionts to the nematode is also common, but its biological importance is unclear. Over 100 nematode species are currently targeted for sequencing, and these data will yield important insights into the biology and evolutionary history of parasitism. It is important that these new technologies are also applied to free-living taxa, so that the pre-parasitic ground state can be inferred, and the novelties associated with parasitism isolated. PMID:24963797

  14. RNA trafficking in parasitic plant systems.

    PubMed

    Leblanc, Megan; Kim, Gunjune; Westwood, James H

    2012-01-01

    RNA trafficking in plants contributes to local and long-distance coordination of plant development and response to the environment. However, investigations of mobile RNA identity and function are hindered by the inherent difficulty of tracing a given molecule of RNA from its cell of origin to its destination. Several methods have been used to address this problem, but all are limited to some extent by constraints associated with accurately sampling phloem sap or detecting trafficked RNA. Certain parasitic plant species form symplastic connections to their hosts and thereby provide an additional system for studying RNA trafficking. The haustorial connections of Cuscuta and Phelipanche species are similar to graft junctions in that they are able to transmit mRNAs, viral RNAs, siRNAs, and proteins from the host plants to the parasite. In contrast to other graft systems, these parasites form connections with host species that span a wide phylogenetic range, such that a high degree of nucleotide sequence divergence may exist between host and parasites and allow confident identification of most host RNAs in the parasite system. The ability to identify host RNAs in parasites, and vice versa, will facilitate genomics approaches to understanding RNA trafficking. This review discusses the nature of host-parasite connections and the potential significance of host RNAs for the parasite. Additional research on host-parasite interactions is needed to interpret results of RNA trafficking studies, but parasitic plants may provide a fascinating new perspective on RNA trafficking. PMID:22936942

  15. Ecological consequences of manipulative parasites: chapter 9

    USGS Publications Warehouse

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

    2012-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. When parasites disagree: evidence for parasite-induced sabotage of host manipulation.

    PubMed

    Hafer, Nina; Milinski, Manfred

    2015-03-01

    Host manipulation is a common parasite strategy to alter host behavior in a manner to enhance parasite fitness usually by increasing the parasite's transmission to the next host. In nature, hosts often harbor multiple parasites with agreeing or conflicting interests over host manipulation. Natural selection might drive such parasites to cooperation, compromise, or sabotage. Sabotage would occur if one parasite suppresses the manipulation of another. Experimental studies on the effect of multi-parasite interactions on host manipulation are scarce, clear experimental evidence for sabotage is elusive. We tested the effect of multiple infections on host manipulation using laboratory-bred copepods experimentally infected with the trophically transmitted tapeworm Schistocephalus solidus. This parasite is known to manipulate its host depending on its own developmental stage. Coinfecting parasites with the same aim enhance each other's manipulation but only after reaching infectivity. If the coinfecting parasites disagree over host manipulation, the infective parasite wins this conflict: the noninfective one has no effect. The winning (i.e., infective) parasite suppresses the manipulation of its noninfective competitor. This presents conclusive experimental evidence for both cooperation in and sabotage of host manipulation and hence a proof of principal that one parasite can alter and even neutralize manipulation by another. PMID:25643621

  18. Canine and feline parasitic zoonoses in China

    PubMed Central

    2012-01-01

    Canine and feline parasitic zoonoses have not been given high priority in China, although the role of companion animals as reservoirs for zoonotic parasitic diseases has been recognized worldwide. With an increasing number of dogs and cats under unregulated conditions in China, the canine and feline parasitic zoonoses are showing a trend towards being gradually uncontrolled. Currently, canine and feline parasitic zoonoses threaten human health, and cause death and serious diseases in China. This article comprehensively reviews the current status of major canine and feline parasitic zoonoses in mainland China, discusses the risks dogs and cats pose with regard to zoonotic transmission of canine and feline parasites, and proposes control strategies and measures. PMID:22839365

  19. Angiogenesis and parasitic helminth-associated neovascularization.

    PubMed

    Dennis, Roger D; Schubert, Uwe; Bauer, Christian

    2011-04-01

    Successful metazoan parasitism, among many other factors, requires a supply of nutrients and the removal of waste products. There is a prerequisite for a parasite-defined vasculature. The angiogenic mechanism(s) involved presumably depend on the characteristics of the tissue- and vascular system-dwelling, parasitic helminths. Simplistically, 2 possibilities or a combination of both have been considered in this review. The multifactorial induction of parasitic helminth-associated neovascularization could arise through, either a host-, a parasite- or a host-/parasite-dependent, angiogenic switch. Most studies appear to support the first and third hypotheses, but evidence exists for the intrahepatic cestode Echinococcus multilocularis, the free-living nematode Caenorhabditis elegans and the intravascular trematode Schistosoma mansoni for the second inference. In contrast, the nematode anti-coagulant protein NAPc2 from adult Ancylostoma caninum is also an anti-angiogenic factor. PMID:21232174

  20. A syndromic approach to common parasitic diseases

    PubMed Central

    Shafran, Stephen D.; Chow, Anthony W.

    1985-01-01

    Standard textbooks discuss parasitic disease according to specific organisms. In contrast, patients with parasitic infections present to physicians with a variety of clinical manifestations that may involve any of several organ systems and that often mimic nonparasitic diseases. A syndromic approach to the clinical situation may help the physician in considering the most important parasitic agents. Many parasitic infections can be acquired in temperate climates. While often considered tropical or exotic, other parasitic diseases are now seen more frequently in developed countries because of immigration and increased world travel. In this review the clinical syndromes associated with common parasitic diseases in North America are discussed, with an emphasis on risk factors and diagnosis of specific infections. PMID:4042057

  1. [Intestinal parasitic infections in Serbia].

    PubMed

    Nikolić, A; Djurković-Djaković, O; Bobić, B

    1998-01-01

    To determine the public health significance of intestinal parasitism in Serbia today, systematic parasitologic examination of 16 regions (Kragujevac, Luchani, Zhagubica, Bor, Sjenica, Novi Pazar, Valjevo, Aleksandrovac, Pirot, Bosilegrad, Ivanjica, Golubac, Uzhice, Kladovo, Negotin, Beograd) in central Serbia were carried out over the period 1984-1993. The study involved a total of 5981 schoolchildren (2887 F, 3094 M), 7-11 years old representing 10% of the total age-matched population (N = 58,228) of the examined regions, residing in 91 settlements. Field parasitological examinations included the examination of perianal swabs for E. vermicularis and Taenia sp., and examination of a single feces sample by direct saline smear and Lugol stained smear for intestinal protozoa, and the Kato and Lörincz methods for intestinal helminths. Nine species of intestinal parasites were detected, of which five protozoan: Entamoeba histolytica (0.02%), Entamoeba hartmanni (0.02%), Entamoeba coli (1.3%), Iodamoeba bütschlii (0.02%), Giardia lamblia (6.8%), and four helminthic: Hymenolepis nana (0.06%), Enterobius vermicularis (14.7%), Ascaris lumbricoides (3.3%), Trichuris trichiura (1.8%). The overall prevalence of intestinal parasite infections amounted to 24.6% (1207/4913), with a highly significant difference (p < 0.001) between particular sites (range 14.4%-43.8%) (Figure 1). Helminthic infections (810) were significantly more frequent (p < 0.001) as compared to both protozoan (296) and combined helminthic-protozoan infections (101). Of these, two species (G. lamblia, E. vermicularis) were found in all examined regions, three (E. coli, A. lumbricoides, T. trichiura) were detected in two or more, while four species (E. histolytica, E. hartmanni, I. bütschlii, H. nana) were each found in a single region (Figure 2). The predominant species (E. coli, G. lamblia, E. vermicularis, A. lumbricoides, T. trichiura) were distributed at considerably different prevalence rates, with a

  2. Parasite vaccines--a reality?

    PubMed

    Dalton, J P; Mulcahy, G

    2001-07-12

    Over the last decade, the anti-parasitics market has been the fastest growing sector of the overall $18 billion animal health market. While drugs for the treatment of parasites of livestock still dominate this sector and will continue to be developed or re-formulated, because of consumer demands for chemical-free food and of concerns regarding the environment and animal welfare there is a growing interest in the development of safe and effective vaccines. There is also a call for vaccines in the lucrative $3 billion-plus companion animal market. These demands for vaccines will add a greater impetus to an area that has seen tremendous success in the last 15 years. A number of anti-parasite vaccines have been developed, e.g. the recombinant 45w and EG95 oncosphere proteins against Taenia ovis and Echinococcus granulosis, respectively, and the Bm86 vaccine against Boophilus microplus. In addition, the cathepsin L vaccines against the liver fluke, Fasciola hepatica, and the H11 vaccine against Haemonchus contortus are progressing well. There are also many additional vaccine candidates for H. contortus and for other nematodes such as Ostertagia and Trichostrongylus spp. that may ultimately lead to broad-spectrum gastrointestinal worm vaccines. Live or attenuated-live vaccines are available for the control of avian coccidiosis, toxplasmosis in sheep and anaplasmosis in cattle, although molecular vaccines against protozoans are still proving elusive. The wealth of information in genomics, proteomics and immunology that has been forthcoming together will new methods of vaccine production and delivery should see many new vaccines reach the marketplace in the near future. PMID:11516584

  3. Parasitic interference in nulling interferometry

    NASA Astrophysics Data System (ADS)

    Matter, A.; Defrère, D.; Danchi, W. C.; Lopez, B.; Absil, O.

    2013-05-01

    Nulling interferometry aims to detect faint objects close to bright stars. Its principle is to produce a destructive interference along the line of sight so that the stellar flux is rejected, while the flux of the off-axis source can be transmitted. In practice, various instrumental perturbations can degrade the nulling performance. Any imperfection in phase, amplitude or polarization produces a spurious flux that leaks to the interferometer output and corrupts the transmitted off-axis flux. One of these instrumental perturbations is the crosstalk phenomenon, which occurs because of multiple parasitic reflections inside transmitting optics, and/or diffraction effects related to beam propagation along finite size optics. It can include a crosstalk of a beam with itself, and a mutual crosstalk between different beams. This can create a parasitic interference pattern, which degrades the intrinsic transmission map - or intensity response - of the interferometer. In this context, we describe how this instrumental effect impairs the performance of a Bracewell interferometer. A simple formalism is developed to derive the corresponding modified intensity response of the interferometer, as a function of the two parameters of interest: the crosstalk level (or contamination rate) and the phase shift between the primary and secondary - parasitic - beams. We then apply our mathematical approach to a few scientific cases, both analytically and using the GENIESIM simulation software, adapted to handle coherent crosstalk. Our results show that a coherent crosstalk level of about 1 per cent implies a 20 per cent drop of the signal-to-noise ratio at most. Careful attention should thus be paid to reduce the crosstalk level inside an interferometric instrument and ensure an instrumental stability that provides the necessary sensitivity through calibration procedures.

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

    PubMed

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

    2013-08-01

    We provide the first evidence of Hepatozoon parasites infecting bats. We sequenced a short fragment of the 18S rRNA gene (~600 base pairs) of Hepatozoon parasites from 3 Hipposideros cervinus bats from Borneo. Phylogenies inferred by model-based methods place these Hepatozoon within a clade formed by parasites of reptiles, rodents, and marsupials. We discuss the scenario that bats might be common hosts of Hepatozoon. PMID:23240742

  5. EVOLUTION: Parasites Make Scaredy-Rats Foolhardy.

    PubMed

    Zimmer, C

    2000-07-28

    In the 7 August issue of the Proceedings of the Royal Society of London B, researchers offer a striking demonstration of the ability of some parasites to alter the behavior of their hosts for their own benefit. Rats, the intermediate hosts of the protozoan Toxoplasma gondii, appear to lose their fear of cats, Toxoplasma's final host, when the parasite infects them. By precisely altering rat brains, the parasite potentially increases its chances of completing its life cycle. PMID:17832058

  6. Parasitic and rare spinal infections.

    PubMed

    do Amaral, Lázaro Luís Faria; Nunes, Renato Hoffmann; da Rocha, Antonio Jose

    2015-05-01

    The imaging features of spinal parasitic diseases and other rare infections are herein discussed. These diseases are distributed worldwide, with increased prevalence in areas with poor sanitary conditions and in developing countries. In nonendemic areas, sporadic cases may occur, consequent to increased international travel and immunocompromising conditions. Infectious diseases are usually treatable, and early detection is often crucial. A thorough comprehension of the imaging patterns associated with the clinical features, epidemiology, and laboratory results allows the radiologist to narrow down the options for differential diagnosis and facilitates the timely implementation of appropriate therapies. PMID:25952177

  7. Parasites in bloom: flowers aid dispersal and transmission of pollinator parasites within and between bee species

    PubMed Central

    Graystock, Peter; Goulson, Dave; Hughes, William O. H.

    2015-01-01

    The dispersal of parasites is critical for epidemiology, and the interspecific vectoring of parasites when species share resources may play an underappreciated role in parasite dispersal. One of the best examples of such a situation is the shared use of flowers by pollinators, but the importance of flowers and interspecific vectoring in the dispersal of pollinator parasites is poorly understood and frequently overlooked. Here, we use an experimental approach to show that during even short foraging periods of 3 h, three bumblebee parasites and two honeybee parasites were dispersed effectively onto flowers by their hosts, and then vectored readily between flowers by non-host pollinator species. The results suggest that flowers are likely to be hotspots for the transmission of pollinator parasites and that considering potential vector, as well as host, species will be of general importance for understanding the distribution and transmission of parasites in the environment and between pollinators. PMID:26246556

  8. Effects of a hurricane on fish parasites.

    PubMed

    Overstreet, R M

    2007-09-01

    Hurricanes, also called tropical cyclones, can dramatically affect life along their paths, including a temporary losing or reducing in number of parasites of fishes. Hurricane Katrina in the northern Gulf of Mexico in August 2005 provides many examples involving humans and both terrestrial and aquatic animals and plants. Fishes do not provide much of an indicator of hurricane activity because most species quickly repopulate the area. Fish parasites, however, serve as a good indicator of the overall biodiversity and environmental health. The reasons for the noted absence or reduction of parasites in fishes are many, and specific parasites provide indications of different processes. The powerful winds can produce perturbations of the sediments harboring intermediate hosts. The surge of high salinity water can kill or otherwise affect low salinity intermediate hosts or free-living stages. Both can introduce toxicants into the habitat and also interfere with the timing and processes involved with host-parasite interrelationships. All these have had a major influence on fish parasite populations of fishes in coastal Mississippi, especially for those parasites incorporating intermediate hosts in their life cycles. The length of time for a parasite to become re-established can vary considerably, depending on its life cycle as well as the associated biota, habitat, and environmental conditions, and each parasite provides a special indicator of environmental health. PMID:18410074

  9. Parasites of cottontail rabbits of southern Illinois.

    PubMed

    Lepitzki, D A; Woolf, A; Bunn, B M

    1992-12-01

    Fifteen species of parasites including Haemaphysalis leporispalustris, Ixodes dentatus, Amblyomma americanum, Cediopsylla simplex, Odontopsyllus multispinosus, Cuterebra sp., Obeliscoides cuniculi, Trichostrongylus calcaratus, Trichostrongylus affinis, Longistriata noviberiae, Dermatoxys veligera, Trichuris sp., Mosgovoyia sp., Taenia pisiformis, and Hasstilesia tricolor as well as coccidia oocysts were collected from 96 cottontail rabbits (Sylvilagus floridanus) confined to a pen in southern Illinois in 1983 and 1984. The diversity of parasites and the intensities of infections were similar to published reports on free-ranging populations. Most variations in parasite abundances were attributable to season. Few lesions were seen in association with parasitism. PMID:1491303

  10. Fish Parasites: A Growing Concern During Pregnancy.

    PubMed

    Villazanakretzer, Diana L; Napolitano, Peter G; Cummings, Kelly F; Magann, Everett F

    2016-04-01

    Intestinal parasitic worms affect more than 2 billion people worldwide according to the World Health Organization. Fish-borne parasitic infections are becoming more common with the increasing popularity of sushi, sashimi, Carpaccio, tartare, gefilte, and ceviche. The ingestion of these parasites can cause serve anemia, malabsorption, severe abdominal pain, nausea, vomiting, strong allergic reactions, and gastric ulcers. Knowledge about fish parasites and pregnancy is limited. A literature search on PubMed and Web of Science used the search terms "fish parasites" OR "diphyllobothrium" OR "anisakiasis" OR "pseudoterranova" OR ("food borne parasites" AND "fish") AND "pregnancy" OR "maternal" OR "fetus" OR "fetal" OR "newborn" OR "neonatal" OR "childbirth." No limit was put on the number of years searched. There were 281 publications identified. The abstracts of all of these publications were read. After exclusion of the articles that were not relevant to pregnancy, pregnancy outcome, and fish parasites, there were 24 articles that became the basis of this review. The pathophysiology, altered maternal immunity related to the infection, limited information about fish-borne parasitic infections and pregnancy, and treatments are discussed. The main impact of a fish-borne parasitic infection on pregnant women is anemia and altered immunity, which may increase the risk of a maternal infection. The primary fetal effects include intrauterine growth restriction and preterm delivery. PMID:27065071

  11. Bold, Sedentary Fathead Minnows Have More Parasites.

    PubMed

    Pan, Tiffany; Gladen, Kelsey; Duncan, Elizabeth C; Cotner, Sehoya; Cotner, James B; McEwen, Daniel C; Wisenden, Brian D

    2016-08-01

    Parasites that rely on trophic transmission can manipulate the behavior of an intermediate host to compromise the host's antipredator competence and increase the probability of reaching the next host. Selection for parasite manipulation is diminished when there is significant risk of host death to causes other than consumption by a suitable definitive host for the parasite. Consequently, behavioral manipulation by parasites can be expected to be subtle. Ornithodiplostomum ptychocheilus (Op) is a trematode parasite that has a bird-snail-fish host life cycle. Fathead minnows are a common intermediate host of Op, where metacercariae encyst in the minnow brain. In this study, we report a link between metacercarial intensity and behavior in fathead minnows. In the field, we found that roaming distance by free-living minnows over 24 h was negatively correlated with parasite intensity. In the laboratory, we found that boldness in an open field test was positively correlated with parasite intensity. These parasite-induced behavioral changes may render infected minnows more susceptible to predators, which would serve to facilitate trophic transmission of parasites to the bird host. PMID:27093037

  12. Parasites in the Wadden Sea food web

    NASA Astrophysics Data System (ADS)

    Thieltges, David W.; Engelsma, Marc Y.; Wendling, Carolin C.; Wegner, K. Mathias

    2013-09-01

    While the free-living fauna of the Wadden Sea has received much interest, little is known on the distribution and effects of parasites in the Wadden Sea food web. However, recent studies on this special type of trophic interaction indicate a high diversity of parasites in the Wadden Sea and suggest a multitude of effects on the hosts. This also includes effects on specific predator-prey relationships and the general structure of the food web. Focussing on molluscs, a major group in the Wadden Sea in terms of biomass and abundance and an important link between primary producers and predators, we review existing studies and exemplify the ecological role of parasites in the Wadden Sea food web. First, we give a brief inventory of parasites occurring in the Wadden Sea, ranging from microparasites (e.g. protozoa, bacteria) to macroparasites (e.g. helminths, parasitic copepods) and discuss the effects of spatial scale on heterogeneities in infection levels. We then demonstrate how parasites can affect host population dynamics by acting as a strong mortality factor, causing mollusc mass mortalities. In addition, we will exemplify how parasites can mediate the interaction strength of predator-prey relationships and affect the topological structure of the Wadden Sea food web as a whole. Finally, we highlight some ongoing changes regarding parasitism in the Wadden Sea in the course of global change (e.g. species introduction, climate change) and identify important future research questions to entangle the role of parasites in the Wadden Sea food web.

  13. Mechanisms of host seeking by parasitic nematodes.

    PubMed

    Gang, Spencer S; Hallem, Elissa A

    2016-07-01

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

  14. Parasite predators exhibit a rapid numerical response to increased parasite abundance and reduce transmission to hosts

    PubMed Central

    Hopkins, Skylar R; Wyderko, Jennie A; Sheehy, Robert R; Belden, Lisa K; Wojdak, Jeremy M

    2013-01-01

    Predators of parasites have recently gained attention as important parts of food webs and ecosystems. In aquatic systems, many taxa consume free-living stages of parasites, and can thus reduce parasite transmission to hosts. However, the importance of the functional and numerical responses of parasite predators to disease dynamics is not well understood. We collected host–parasite–predator cooccurrence data from the field, and then experimentally manipulated predator abundance, parasite abundance, and the presence of alternative prey to determine the consequences for parasite transmission. The parasite predator of interest was a ubiquitous symbiotic oligochaete of mollusks, Chaetogaster limnaei limnaei, which inhabits host shells and consumes larval trematode parasites. Predators exhibited a rapid numerical response, where predator populations increased or decreased by as much as 60% in just 5 days, depending on the parasite:predator ratio. Furthermore, snail infection decreased substantially with increasing parasite predator densities, where the highest predator densities reduced infection by up to 89%. Predators of parasites can play an important role in regulating parasite transmission, even when infection risk is high, and especially when predators can rapidly respond numerically to resource pulses. We suggest that these types of interactions might have cascading effects on entire disease systems, and emphasize the importance of considering disease dynamics at the community level. PMID:24340184

  15. How Many Parasites Species a Frog Might Have? Determinants of Parasite Diversity in South American Anurans

    PubMed Central

    Campião, Karla Magalhães; Ribas, Augusto Cesar de Aquino; Morais, Drausio Honorio; da Silva, Reinaldo José; Tavares, Luiz Eduardo Roland

    2015-01-01

    There is an increasing interest in unveiling the dynamics of parasite infection. Understanding the interaction patterns, and determinants of host-parasite association contributes to filling knowledge gaps in both community and disease ecology. Despite being targeted as a relevant group for conservation efforts, determinants of the association of amphibians and their parasites in broad scales are poorly understood. Here we describe parasite biodiversity in South American amphibians, testing the influence of host body size and geographic range in helminth parasites species richness (PSR). We also test whether parasite diversity is related to hosts’ phylogenetic diversity. Results showed that nematodes are the most common anuran parasites. Host-parasite network has a nested pattern, with specialist helminth taxa generally associated with hosts that harbour the richest parasite faunas. Host size is positively correlated with helminth fauna richness, but we found no support for the association of host geographic range and PSR. These results remained consistent after correcting for uneven study effort and hosts’ phylogenic correlation. However, we found no association between host and parasite diversity, indicating that more diversified anuran clades not necessarily support higher parasite diversity. Overall, considering both the structure and the determinants of PRS in anurans, we conclude that specialist parasites are more likely to be associated with large anurans, which are the ones harbouring higher PSR, and that the lack of association of PSR with hosts’ clade diversification suggests it is strongly influenced by ecological and contemporary constrains. PMID:26473593

  16. [Trichostrongyloidea nematodes, parasites of Microchiroptera].

    PubMed

    Durette-Desset, M C; Chabaud, A G

    1975-01-01

    1. a) List of Nematodes collected by Professor Aellen in european Microchiroptera. Additionnal morphological data to the study of Molinostrongylus alatus, M. panousei, M. skrjabini. Description of M. aelleni n. sp. b) Description of M. richardae n. sp., M. benexae n. sp. et M. bauchoti n. sp., parasites of malagasian Molossidae. c) Description of M. colleyi n. sp. and M. owyangi n. sp., parasites of Malaysian Vespertilioninae, and of Allintoschius dunni n. sp., discovered in Myotis mystacinus from Malaysia and Pipistrellus nanus from Africa. 2. Taking into account the characteristics of the synlophe, the 17 species of the genus Molinostrongylus may be divided into five groups, each one being reasonably well characteristic of the genus of their Chiropteran host. 3. The composition of the Trichostrongyloidea fauna of Chiroptera and its relationship with Trichostrongyloidea from other Mammals (Tupaiidae, Pholidotes, Primates, Sciuridés) are analysed. Six groups are separated and divided into two well defined lines: 1) genus Strongylacantha, and 2) 12 genera stemming more or less directly from the Molineinae, 4. The three conical outgrowths at the tip of the female tail which differenciate presently the Anoplostrogylinae from the Molineinae appear to be an unreliable characteristic. The two subfamilies form a complex group which will be better understood if the evolution of the synlophe and that of the caudal bursa of the males are taken into account. PMID:1211768

  17. Apoptotic markers in protozoan parasites

    PubMed Central

    2010-01-01

    The execution of the apoptotic death program in metazoans is characterized by a sequence of morphological and biochemical changes that include cell shrinkage, presentation of phosphatidylserine at the cell surface, mitochondrial alterations, chromatin condensation, nuclear fragmentation, membrane blebbing and the formation of apoptotic bodies. Methodologies for measuring apoptosis are based on these markers. Except for membrane blebbing and formation of apoptotic bodies, all other events have been observed in most protozoan parasites undergoing cell death. However, while techniques exist to detect these markers, they are often optimised for metazoan cells and therefore may not pick up subtle differences between the events occurring in unicellular organisms and multi-cellular organisms. In this review we discuss the markers most frequently used to analyze cell death in protozoan parasites, paying special attention to changes in cell morphology, mitochondrial activity, chromatin structure and plasma membrane structure/permeability. Regarding classical regulators/executors of apoptosis, we have reviewed the present knowledge of caspase-like and nuclease activities. PMID:21062457

  18. An ABA-responsive DRE-binding protein gene from Setaria italica, SiARDP, the target gene of SiAREB, plays a critical role under drought stress

    PubMed Central

    Li, Cong; Yue, Jing; Wu, Xiaowei; Xu, Cong; Yu, Jingjuan

    2014-01-01

    The DREB (dehydration-responsive element binding)-type transcription factors regulate the expression of stress-inducible genes by binding the DRE/CRT cis-elements in promoter regions. The upstream transcription factors that regulate the transcription of DREB transcription factors have not been clearly defined, although the function of DREB transcription factors in abiotic stress is known. In this study, an abscisic acid (ABA)-responsive DREB-binding protein gene (SiARDP) was cloned from foxtail millet (Setaria italica). The transcript level of SiARDP increased not only after drought, high salt, and low temperature stresses, but also after an ABA treatment in foxtail millet seedlings. Two ABA-responsive elements (ABRE1: ACGTGTC; ABRE2: ACGTGGC) exist in the promoter of SiARDP. Further analyses showed that two ABA-responsive element binding (AREB)-type transcription factors, SiAREB1 and SiAREB2, could physically bind to the ABRE core element in vitro and in vivo. The constitutive expression of SiARDP in Arabidopsis thaliana enhanced drought and salt tolerance during seed germination and seedling development, and overexpression of SiARDP in foxtail millet improved drought tolerance. The expression levels of target genes of SiARDP were upregulated in transgenic Arabidopsis and foxtail millet. These results reveal that SiARDP, one of the target genes of SiAREB, is involved in ABA-dependent signal pathways and plays a critical role in the abiotic stress response in plants. PMID:25071221

  19. The C-terminal motif of SiAGO1b is required for the regulation of growth, development and stress responses in foxtail millet (Setaria italica (L.) P. Beauv).

    PubMed

    Liu, Xiaotong; Tang, Sha; Jia, Guanqing; Schnable, James C; Su, Haixia; Tang, Chanjuan; Zhi, Hui; Diao, Xianmin

    2016-05-01

    Foxtail millet (Setaria italica (L.) P. Beauv), which belongs to the Panicoideae tribe of the Poaceae, is an important grain crop widely grown in Northern China and India. It is currently developing into a novel model species for functional genomics of the Panicoideae as a result of its fully available reference genome sequence, small diploid genome (2n=18, ~510Mb), short life cycle, small stature and prolific seed production. Argonaute 1 (AGO1), belonging to the argonaute (AGO) protein family, recruits small RNAs and regulates plant growth and development. Here, we characterized an AGO1 mutant (siago1b) in foxtail millet, which was induced by ethyl methanesulfonate treatment. The mutant exhibited pleiotropic developmental defects, including dwarfing stem, narrow and rolled leaves, smaller panicles and lower rates of seed setting. Map-based cloning analysis demonstrated that these phenotypic variations were attributed to a C-A transversion, and a 7-bp deletion in the C-terminus of the SiAGO1b gene in siago1b Yeast two-hybrid assays and BiFC experiments revealed that the mutated region was an essential functional motif for the interaction between SiAGO1b and SiHYL1. Furthermore, 1598 differentially expressed genes were detected via RNA-seq-based comparison of SiAGO1b and wild-type plants, which revealed that SiAGO1b mutation influenced multiple biological processes, including energy metabolism, cell growth, programmed death and abiotic stress responses in foxtail millet. This study may provide a better understanding of the mechanisms by which SiAGO1b regulates the growth and development of crops. PMID:27045099

  20. The C-terminal motif of SiAGO1b is required for the regulation of growth, development and stress responses in foxtail millet (Setaria italica (L.) P. Beauv)

    PubMed Central

    Liu, Xiaotong; Tang, Sha; Jia, Guanqing; Schnable, James C.; Su, Haixia; Tang, Chanjuan; Zhi, Hui; Diao, Xianmin

    2016-01-01

    Foxtail millet (Setaria italica (L.) P. Beauv), which belongs to the Panicoideae tribe of the Poaceae, is an important grain crop widely grown in Northern China and India. It is currently developing into a novel model species for functional genomics of the Panicoideae as a result of its fully available reference genome sequence, small diploid genome (2n=18, ~510Mb), short life cycle, small stature and prolific seed production. Argonaute 1 (AGO1), belonging to the argonaute (AGO) protein family, recruits small RNAs and regulates plant growth and development. Here, we characterized an AGO1 mutant (siago1b) in foxtail millet, which was induced by ethyl methanesulfonate treatment. The mutant exhibited pleiotropic developmental defects, including dwarfing stem, narrow and rolled leaves, smaller panicles and lower rates of seed setting. Map-based cloning analysis demonstrated that these phenotypic variations were attributed to a C–A transversion, and a 7-bp deletion in the C-terminus of the SiAGO1b gene in siago1b. Yeast two-hybrid assays and BiFC experiments revealed that the mutated region was an essential functional motif for the interaction between SiAGO1b and SiHYL1. Furthermore, 1598 differentially expressed genes were detected via RNA-seq-based comparison of SiAGO1b and wild-type plants, which revealed that SiAGO1b mutation influenced multiple biological processes, including energy metabolism, cell growth, programmed death and abiotic stress responses in foxtail millet. This study may provide a better understanding of the mechanisms by which SiAGO1b regulates the growth and development of crops. PMID:27045099

  1. Ecology and biogeography of marine parasites.

    PubMed

    Rohde, Klaus

    2002-01-01

    A review is given of (mainly recent) work on the biodiversity, ecology, biogeography and practical importance of marine parasites. Problems in estimating species numbers have been thoroughly discussed for free-living species, and the main points of these discussions are reviewed here. Even rough estimates of the richness of most parasite groups in the oceans are premature for the following reasons: species numbers of host groups, in particular in the deep sea and the meiofauna, are not known; most host groups have been examined only insufficiently for parasites or not at all; even in some of the best known groups, latitudinal, longitudinal and depth gradients in species richness are only poorly understood or not known at all; effects of hosts on parasite morphology and geographical variation have been studied only in a few cases; there are few studies using techniques of molecular biology to distinguish sibling species. Estimates of species richness in the best known groups, trematodes, monogeneans and copepods of marine fishes, are given. Parasites are found in almost all taxa of eukaryotes, but most parasitic species are concentrated in a few taxa. Important aspects of the ecology of marine parasites are discussed. It is emphasized that host specificity and host ranges should be distinguished, and an index that permits calculation of host specificity is discussed. The same index can be applied to measure site specificity. Central problems in ecology are the importance of interspecific competition and whether equilibrium or non-equilibrium conditions prevail. Marine parasites are among the few groups of organisms that have been extensively examined in this regard. A holistic approach, i.e. application of many methods, has unambiguously shown that metazoan ecto- (and probably endo-) parasites of marine fish live in largely non-saturated niche space under non-equilibrium conditions, i.e. they live in assemblages rather than in communities structured by competition

  2. Batflies parasitic on some phyllostomid bats in southeastern Brazil: parasitism rates and host-parasite relationships.

    PubMed

    Komeno, C A; Linhares, A X

    1999-01-01

    Ectoparasitic batflies were studied on 12 species of phyllostomid bats, by making 35 nightly collections of bats using mist nets at the "Panga" Ecological Reservation near Uberlândia, State of Minas Gerais, southeastern Brazil, from August 1989 to July 1990. Eleven species of Streblidae and one of Nycteribiidae were collected on 12 species of bats. Prevalence of ectoparasitic flies was lower than those reported by other authors for the New World and may be the result of the lack of caves in the study area, causing bats to roost in less favorable locations, forming smaller colonies. The fly, Trichobius joblingi Wenzel, was found on Carollia perspicillata (Linnaeus), showing preference for adult male bats. This could be explained by the predominance of males in the bat colonies, and by the fact that females rest in isolation during the reproductive period making them less exposed to the parasites. The streblid flies, Aspidoptera falcata Wenzel and Megistopoda proxima (Séguy), were found on Sturnira lilium (Geoffroy). A. falcata occurred mainly on young and adult females, whereas M. proxima did not show any preferences relative to the reproductive condition of the host. Ecological factors are important in determining differential numbers of parasites occurring on the different sexes, ages and reproductive state of the hosts. PMID:10224519

  3. Realizing the promise of parasite genomics.

    PubMed

    Wasmuth, James D

    2014-07-01

    Genomes and genomics are now part of the popular imagination and culture. Understanding what these massively long strings of As, Gs, Cs, and Ts actually mean is a challenge that has been taken up by many working on parasites. Our understanding of parasite biology and future treatment strategies has been significantly improved because of these genomes. PMID:24981572

  4. Blood parasites from California ducks and geese

    USGS Publications Warehouse

    Herman, C.M.

    1951-01-01

    Blood smears were procured from 1,011 geese and ducks of 19 species from various locations in California. Parasites were found in 28 individuals. The parasites observed included Haemoproteus hermani, Leucocytozoon simondi, microfilaria, Plasmodium relictum (=P. biziurae), and Plasmodium sp. with elongate gametocytes. This is the first report of a natural infection with a Plasmodium in North American wild ducks.

  5. Interactions of microfungi and plant parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Parasitic Nematodes - From Genomes to Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. The adaptive significance of inquiline parasite workers.

    PubMed Central

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

    2003-01-01

    Social parasites exploit the socially managed resources of their host's society. Inquiline social parasites are dependent on their host throughout their life cycle, and so many of the traits inherited from their free-living ancestor are removed by natural selection. One trait that is commonly lost is the worker caste, the functions of which are adequately fulfilled by host workers. The few inquiline parasites that have retained a worker caste are thought to be at a transitional stage in the evolution of social parasitism, and their worker castes are considered vestigial and non-adaptive. However, this idea has not been tested. Furthermore, whether inquiline workers have an adaptive role outside the usual worker repertoire of foraging, brood care and colony maintenance has not been examined. In this paper, we present data that suggest that workers of the inquiline ant Acromyrmex insinuator play a vital role in ensuring the parasite's fitness. We show that the presence of these parasite workers has a positive effect on the production of parasite sexuals and a negative effect on the production of host sexuals. This suggests that inquiline workers play a vital role in suppressing host queen reproduction, thus promoting the rearing of parasite sexuals. To our knowledge, these are the first experiments on inquiline workers and the first to provide evidence that inquiline workers have an adaptive role. PMID:12816646

  8. Parasitic Skin Infections for Primary Care Physicians.

    PubMed

    Dadabhoy, Irfan; Butts, Jessica F

    2015-12-01

    The 2 epidermal parasitic skin infections most commonly encountered by primary care physicians in developed countries are scabies and pediculosis. Pediculosis can be further subdivided into pediculosis capitis, corporis, and pubis. This article presents a summary of information and a review of the literature on clinical findings, diagnosis, and treatment of these commonly encountered parasitic skin infestations. PMID:26612378

  9. Predicting optimal transmission investment in malaria parasites.

    PubMed

    Greischar, Megan A; Mideo, Nicole; Read, Andrew F; Bjørnstad, Ottar N

    2016-07-01

    In vertebrate hosts, malaria parasites face a tradeoff between replicating and the production of transmission stages that can be passed onto mosquitoes. This tradeoff is analogous to growth-reproduction tradeoffs in multicellular organisms. We use a mathematical model tailored to the life cycle and dynamics of malaria parasites to identify allocation strategies that maximize cumulative transmission potential to mosquitoes. We show that plastic strategies can substantially outperform fixed allocation because parasites can achieve greater fitness by investing in proliferation early and delaying the production of transmission stages. Parasites should further benefit from restraining transmission investment later in infection, because such a strategy can help maintain parasite numbers in the face of resource depletion. Early allocation decisions are predicted to have the greatest impact on parasite fitness. If the immune response saturates as parasite numbers increase, parasites should benefit from even longer delays prior to transmission investment. The presence of a competing strain selects for consistently lower levels of transmission investment and dramatically increased exploitation of the red blood cell resource. While we provide a detailed analysis of tradeoffs pertaining to malaria life history, our approach for identifying optimal plastic allocation strategies may be broadly applicable. PMID:27271841

  10. Parasites in terrestrial, freshwater and marine systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parasites are ubiquitous and diverse members of all biological communities. Macroparasites (worms and arthropods) and microparasites (viruses, bacteria and protozoans) have at least one life stage that must live on or in another species, or host, which is usually free-living. Parasites can have sub...

  11. Parasite stress promotes homicide and child maltreatment

    PubMed Central

    Thornhill, Randy; Fincher, Corey L.

    2011-01-01

    Researchers using the parasite-stress theory of human values have discovered many cross-cultural behavioural patterns that inform a range of scholarly disciplines. Here, we apply the theory to major categories of interpersonal violence, and the empirical findings are supportive. We hypothesize that the collectivism evoked by high parasite stress is a cause of adult-on-adult interpersonal violence. Across the US states, parasite stress and collectivism each positively predicts rates of men's and women's slaying of a romantic partner, as well as the rate of male-honour homicide and of the motivationally similar felony-related homicide. Of these four types of homicide, wealth inequality has an independent effect only on rates of male-honour and felony-related homicide. Parasite stress and collectivism also positively predict cross-national homicide rates. Child maltreatment by caretakers is caused, in part, by divestment in offspring of low phenotypic quality, and high parasite stress produces more such offspring than low parasite stress. Rates of each of two categories of the child maltreatment—lethal and non-lethal—across the US states are predicted positively by parasite stress, with wealth inequality and collectivism having limited effects. Parasite stress may be the strongest predictor of interpersonal violence to date. PMID:22042922

  12. Microstrip antenna arrays with parasitic elements

    NASA Technical Reports Server (NTRS)

    Lee, Kai-Fong

    1996-01-01

    This research was concerned with using parasitic elements to improve the bandwidth, gain and axial ratio characteristics of microstrip antennas and arrays. Significant improvements in these characteristics were obtained using stacked and coplanar parasitic elements. Details of the results are described in a total of 16 journal and 17 conference papers. These are listed in Section four of this report.

  13. The parasite connection in ecosystems and macroevolution

    NASA Astrophysics Data System (ADS)

    Seilacher, Adolf; Reif, Wolf-Ernst; Wenk, Peter

    2007-03-01

    In addition to their obvious negative effects (“pathogens”), endoparasites of various kinds play an important role in shaping and maintaining modern animal communities. In the long-term, parasites including pathogens are indispensable entities of any ecosystem. To understand this, it is essential that one changes the viewpoint from the host’s interests to that of the parasite. Together with geographic isolation, trophic arms race, symbiosis, and niche partitioning, all parasites (including balance strategists, i.e. seemingly non-pathogenic ones) modulate their hosts’ population densities. In addition, heteroxenic parasites control the balance between predator and prey species, particularly if final and intermediate hosts are vertebrates. Thereby, such parasites enhance the bonds in ecosystems and help maintain the status quo. As the links between eukaryotic parasites and their hosts are less flexible than trophic connections, parasite networks probably contributed to the observed stasis and incumbency of ecosystems over geologic time, in spite of continuous Darwinian innovation. Because heteroxenic parasites target taxonomic levels above that of the species (e.g. families), these taxa may have also become units of selection in global catastrophies. Macroevolutionary extrapolations, however, are difficult to verify because endoparasites cannot fossilize.

  14. First report of Orobanche ludoviciana parasitizing sunflowers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Broomrape is the common name given to a group of flowering plants belonging to the genus Orobanche that parasitize the roots of higher dicotyledonous plants. More than 100 species of Orobanche have been identified, all of which are obligate parasites that lack chlorophyll and depend upon their host ...

  15. Trichinella spiralis: the evolution of adaptation and parasitism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parasitism among nematodes has occurred in multiple, independent events. Deciphering processes that drive species diversity and adaptation are keys to understanding parasitism and advancing control strategies. Studies have been put forth on morphological and physiological aspects of parasitism and a...

  16. From Fossil Parasitoids to Vectors: Insects as Parasites and Hosts.

    PubMed

    Nagler, Christina; Haug, Joachim T

    2015-01-01

    Within Metazoa, it has been proposed that as many as two-thirds of all species are parasitic. This propensity towards parasitism is also reflected within insects, where several lineages independently evolved a parasitic lifestyle. Parasitic behaviour ranges from parasitic habits in the strict sense, but also includes parasitoid, phoretic or kleptoparasitic behaviour. Numerous insects are also the host for other parasitic insects or metazoans. Insects can also serve as vectors for numerous metazoan, protistan, bacterial and viral diseases. The fossil record can report this behaviour with direct (parasite associated with its host) or indirect evidence (insect with parasitic larva, isolated parasitic insect, pathological changes of host). The high abundance of parasitism in the fossil record of insects can reveal important aspects of parasitic lifestyles in various evolutionary lineages. For a comprehensive view on fossil parasitic insects, we discuss here different aspects, including phylogenetic systematics, functional morphology and a direct comparison of fossil and extant species. PMID:26597067

  17. PARASITES IN SOUTHERN SLUDGES AND DISINFECTION BY STANDARD SLUDGE TREATMENT

    EPA Science Inventory

    Major objectives were to: (a) assess types and densities of parasites in municipal wastewater sludges in the southern United States, (b) investigate the inactivation of parasites by lime stabilization of sewage sludges seeded with selected intestinal parasites, (c) assess convent...

  18. Palaeoparasitology - Human Parasites in Ancient Material.

    PubMed

    Araújo, Adauto; Reinhard, Karl; Ferreira, Luiz Fernando

    2015-01-01

    Parasite finds in ancient material launched a new field of science: palaeoparasitology. Ever since the pioneering studies, parasites were identified in archaeological and palaeontological remains, some preserved for millions of years by fossilization. However, the palaeoparasitological record consists mainly of parasites found specifically in human archaeological material, preserved in ancient occupation sites, from prehistory until closer to 2015. The results include some helminth intestinal parasites still commonly found in 2015, such as Ascaris lumbricoides, Trichuris trichiura and hookworms, besides others such as Amoebidae and Giardia intestinalis, as well as viruses, bacteria, fungi and arthropods. These parasites as a whole provide important data on health, diet, climate and living conditions among ancient populations. This chapter describes the principal findings and their importance for knowledge on the origin and dispersal of infectious diseases. PMID:26597072

  19. PARASITES AND POVERTY: THE CASE OF SCHISTOSOMIASIS

    PubMed Central

    King, Charles H.

    2009-01-01

    Simultaneous and sequential transmission of multiple parasites, and their resultant overlapping chronic infections, are facts of life in many underdeveloped rural areas. These represent significant but often poorly-measured health and economic burdens for affected populations. For example, the chronic inflammatory process associated with long-term schistosomiasis contributes to anaemia and undernutrition, which, in turn, can lead to growth stunting, poor school performance, poor work productivity, and continued poverty. To date, most national and international programs aimed at parasite control have not considered the varied economic and ecological factors underlying multi-parasite transmission, but some are beginning to provide a coordinated approach to control. In addition, interest is emerging in new studies for the re-evaluation and recalibration of the health burden of helminthic parasite infection. Their results should highlight the strong potential of integrated parasite control in efforts for poverty reduction. PMID:19962954

  20. Encysted parasitic larvae in the mouth.

    PubMed

    Hansen, L S; Allard, R H

    1984-04-01

    Oral appearances of intestinal parasitic disease are rare. One such appearance is the presence in oral tissues of encysted or encapsulated larvae of organisms from the classes Cestoidea and Nematoda. Cestode larvae form cyst-like lesions that are often clinically diagnosed as mucoceles. In these lesions, the cyst cavity is lined by fibrous tissue with inflammatory cells, and contains fluid and the larval stage of a parasite. The diagnosis of these parasitic cysts is more frequently made in younger persons. The cysts may be treated by simple excision, but care must be taken that the cyst does not rupture, as in some parasites this may result in new cyst formation. Nematode infection in the oral cavity, the most common of which appears to be trichinosis, is rarely reported. Patients with oral or maxillofacial (or both) parasitic disease must undergo a thorough medical investigation to exclude possible life-threatening involvement in other parts of the body. PMID:6586809

  1. Climate change and parasitic disease: farmer mitigation?

    PubMed

    Morgan, Eric R; Wall, Richard

    2009-07-01

    Global climate change predictions suggest that far-ranging effects might occur in the population dynamics and distributions of livestock parasites, provoking fears of widespread increases in disease incidence and production loss. However, several biological mechanisms (including increased parasite mortality and more rapid acquisition of immunity), in tandem with changes in husbandry practices (including reproduction, housing, nutrition, breed selection, grazing patterns and other management interventions), might act to mitigate increased parasite development rates, preventing dramatic rises in overall levels of disease. Such changes might, therefore, counteract predicted climate-driven increases in parasite challenge. Optimum mitigation strategies will be highly system specific and depend on detailed understanding of interactions between climate, parasite abundance, host availability and the cues for and economics of farmer intervention. PMID:19540163

  2. Parasites and poverty: the case of schistosomiasis.

    PubMed

    King, Charles H

    2010-02-01

    Simultaneous and sequential transmission of multiple parasites, and their resultant overlapping chronic infections, are facts of life in many underdeveloped rural areas. These represent significant but often poorly measured health and economic burdens for affected populations. For example, the chronic inflammatory process associated with long-term schistosomiasis contributes to anaemia and undernutrition, which, in turn, can lead to growth stunting, poor school performance, poor work productivity, and continued poverty. To date, most national and international programs aimed at parasite control have not considered the varied economic and ecological factors underlying multi-parasite transmission, but some are beginning to provide a coordinated approach to control. In addition, interest is emerging in new studies for the re-evaluation and recalibration of the health burden of helminthic parasite infection. Their results should highlight the strong potential of integrated parasite control in efforts for poverty reduction. PMID:19962954

  3. Coevolutionary interactions between host and parasite genotypes.

    PubMed

    Lambrechts, Louis; Fellous, Simon; Koella, Jacob C

    2006-01-01

    More than 20 years after Dawkins introduced the concept of "extended phenotype" (i.e. phenotypes of hosts and parasites result from interactions between the two genomes) and although this idea has now reached contemporary textbooks of evolutionary biology, most studies of the evolution of host-parasite systems still focus solely on either the host or the parasite, neglecting the role of the other partner. It is important to consider that host and parasite genotypes share control of the epidemiological parameters of their relationship. Moreover, not only the traits of the infection but also the genetic correlations among these and other traits that determine fitness might be controlled by interactions between host and parasite genotypes. PMID:16310412

  4. The Berkeley parasitic SETI program

    NASA Technical Reports Server (NTRS)

    Bowyer, S.; Zeitlin, G.; Tarter, J.; Lampton, M.; Welch, W. J.

    1983-01-01

    Parasitic programs for the Search for Extraterrestrial Intelligence (SETI), carried out concurrently with conventional radio astronomical observing programs, can be an attractive and cost-effective means of exploring the large multidimensional search space intrinsic to this effort. A microprocessor-based automated SETI acquisition system is described which searches for, and records, spectra of narrowband signals in the IF band of an observatory receiver. Data taken with this system over 35 days at the Hat Creek Radio Observatory at 1612 MHz are discussed. Out of approximately 100,000 spectra processed during this period, 4000 were identified by the system as containing narrowband signals and were recorded. Subsequent analysis indicates that over 3900 of these are due to local RF contamination. The remainder are undergoing further investigation.

  5. Ecology of avian brood parasitism at an early interfacing of host and parasite populations

    USGS Publications Warehouse

    Wiley, J.W.

    1982-01-01

    The shiny cowbird (Molothrus bonariensis), a brood parasite, has recently spread into the Greater Antilles from South America via the Lesser Antilles. This species is a host generalist and upon reaching Puerto Rico exploited avian communities with no history of social parasitism. Forty-two percent of the resident non-raptorial land bird species were parasitized in mangrove habitat study areas. Cowbird parasitism affected hosts by (1) depressing nest success an average of 41 percent below non-parasitized nests, and (2) reducing host productivity. Parasitized hosts produced 12 percent fewer eggs and fledged 67 percent fewer of their own chicks than non-parasitized pairs. Growth rates of chicks of some host species were lower in parasitized nests compared with non-parasitized nests while growth of others was not affected by brood parasitism. Cowbird chick growth varied directly with host size; i.e., cowbird chicks grew faster and attained greater fledging weight and body size in nests of larger hosts. Factors important in shiny cowbird host selection were examined within the mangrove study community. Cowbirds did not parasitize avian species in proportion to their abundance. The cowbird breeding season coincided with that of its major hosts, which were high quality foster species, and did not extend into other periods even though nests of poor quality species were available. Food habits and egg size of cowbirds were similar to those of their hosts, suggesting that cowbirds choose hosts partly on the basis of this alignment. Cowbirds locate nests by cryptically watching activities of birds in likely habitat. Despite the recency of the cowbird's arrival in Puerto Rico, some nesting species have effective anti-parasite strategies, including alien egg rejection and nest guarding. Behavior effective in avoiding parasitism is similar to that used by certain birds in evading nest predators. It is suggested that anti-predator behavior is preadaptive to countering cowbird

  6. Plants that attack plants: molecular elucidation of plant parasitism.

    PubMed

    Yoshida, Satoko; Shirasu, Ken

    2012-12-01

    Obligate parasitic plants in the family Orobanchaceae, such as Striga and Orobanche (including Phelipanche) spp., parasitize important crops and cause severe agricultural damage. Recent molecular studies have begun to reveal how these parasites have adapted to hosts in a parasitic lifecycle. The parasites detect nearby host roots and germinate by a mechanism that seems to have evolved from a conserved germination system found in non-parasites. The development of a specialized infecting organ called a haustorium is a unique feature of plant parasites and is triggered by host compounds and redox signals. Newly developed genomic and genetic resources will facilitate more rapid progress toward a molecular understanding of plant parasitism. PMID:22898297

  7. Parasitism and the expression of sexual dimorphism.

    PubMed

    De Lisle, Stephen P; Rowe, Locke

    2015-02-01

    Although a negative covariance between parasite load and sexually selected trait expression is a requirement of few sexual selection models, such a covariance may be a general result of life-history allocation trade-offs. If both allocation to sexually selected traits and to somatic maintenance (immunocompetence) are condition dependent, then in populations where individuals vary in condition, a positive covariance between trait expression and immunocompetence, and thus a negative covariance between trait and parasite load, is expected. We test the prediction that parasite load is generally related to the expression of sexual dimorphism across two breeding seasons in a wild salamander population and show that males have higher trematode parasite loads for their body size than females and that a key sexually selected trait covaries negatively with parasite load in males. We found evidence of a weaker negative relationship between the analogous female trait and parasite infection. These results underscore that parasite infection may covary with expression of sexually selected traits, both within and among species, regardless of the model of sexual selection, and also suggest that the evolution of condition dependence in males may affect the evolution of female trait expression. PMID:25750721

  8. Parasitism and phenotypic change in colonial hosts.

    PubMed

    Hartikainen, Hanna; Fontes, Inês; Okamura, Beth

    2013-09-01

    Changes in host phenotype are often attributed to manipulation that enables parasites to complete trophic transmission cycles. We characterized changes in host phenotype in a colonial host–endoparasite system that lacks trophic transmission (the freshwater bryozoan Fredericella sultana and myxozoan parasite Tetracapsuloides bryosalmonae). We show that parasitism exerts opposing phenotypic effects at the colony and module levels. Thus, overt infection (the development of infectious spores in the host body cavity) was linked to a reduction in colony size and growth rate, while colony modules exhibited a form of gigantism. Larger modules may support larger parasite sacs and increase metabolite availability to the parasite. Host metabolic rates were lower in overtly infected relative to uninfected hosts that were not investing in propagule production. This suggests a role for direct resource competition and active parasite manipulation (castration) in driving the expression of the infected phenotype. The malformed offspring (statoblasts) of infected colonies had greatly reduced hatching success. Coupled with the severe reduction in statoblast production this suggests that vertical transmission is rare in overtly infected modules. We show that although the parasite can occasionally infect statoblasts during overt infections, no infections were detected in the surviving mature offspring, suggesting that during overt infections, horizontal transmission incurs a trade-off with vertical transmission. PMID:23965820

  9. The rediscovery of malaria parasites of ungulates.

    PubMed

    Templeton, Thomas J; Martinsen, Ellen; Kaewthamasorn, Morakot; Kaneko, Osamu

    2016-10-01

    Over a hundred years since their first description in 1913, the sparsely described malaria parasites (genus Plasmodium) of ungulates have been rediscovered using molecular typing techniques. In the span of weeks, three studies have appeared describing the genetic characterization and phylogenetic analyses of malaria parasites from African antelope (Cephalophus spp.) and goat (Capra aegagrus hircus), Asian water buffalo (Bubalus bubalis), and North American white-tailed deer (Odocoileus virginianus). Here we unify the contributions from those studies with the literature on pre-molecular characterizations of ungulate malaria parasites, which are largely based on surveys of Giemsa-reagent stained blood smears. We present a phylogenetic tree generated from all available ungulate malaria parasite sequence data, and show that parasites from African duiker antelope and goat, Asian water buffalo and New World white-tailed deer group together in a clade, which branches early in Plasmodium evolution. Anopheline mosquitoes appear to be the dominant, if not sole vectors for parasite transmission. We pose questions for future phylogenetic studies, and discuss topics that we hope will spur further molecular and cellular studies of ungulate malaria parasites. PMID:27444556

  10. Blood parasites in reptiles imported to Germany.

    PubMed

    Halla, Ursula; Ursula, Halla; Korbel, Rüdiger; Rüdiger, Korbel; Mutschmann, Frank; Frank, Mutschmann; Rinder, Monika; Monika, Rinder

    2014-12-01

    Though international trade is increasing, the significance of imported reptiles as carriers of pathogens with relevance to animal and human health is largely unknown. Reptiles imported to Germany were therefore investigated for blood parasites using light microscopy, and the detected parasites were morphologically characterized. Four hundred ten reptiles belonging to 17 species originating from 11 Asian, South American and African countries were included. Parasites were detected in 117 (29%) of individual reptiles and in 12 species. Haemococcidea (Haemogregarina, Hepatozoon, Schellackia) were found in 84% of snakes (Python regius, Corallus caninus), 20% of lizards (Acanthocercus atricollis, Agama agama, Kinyongia fischeri, Gekko gecko) and 50% of turtles (Pelusios castaneus). Infections with Hematozoea (Plasmodium, Sauroplasma) were detected in 14% of lizards (Acanthocercus atricollis, Agama agama, Agama mwanzae, K. fischeri, Furcifer pardalis, Xenagama batillifera, Acanthosaura capra, Physignathus cocincinus), while those with Kinetoplastea (Trypanosoma) were found in 9% of snakes (Python regius, Corallus caninus) and 25 % of lizards (K. fischeri, Acanthosaura capra, G. gecko). Nematoda including filarial larvae parasitized in 10% of lizards (Agama agama, Agama mwanzae, K. fischeri, Fu. pardalis, Physignathus cocincinus). Light microscopy mostly allowed diagnosis of the parasites' genus, while species identification was not possible because of limited morphological characteristics available for parasitic developmental stages. The investigation revealed a high percentage of imported reptiles being carriers of parasites while possible vectors and pathogenicity are largely unknown so far. The spreading of haemoparasites thus represents an incalculable risk for pet reptiles, native herpetofauna and even human beings. PMID:25324132

  11. Research needs on internal parasites of horses.

    PubMed

    1984-08-01

    The importance of the horse industry to the economy of the United States and the impact of parasitic infections on the industry are well documented. However, contemporary research activity on internal parasites of horses has not kept pace with growth of the horse population. Parasitic infections are a major facet of enteritis and colic in horses. Parasites are also associated with poor growth and development, respiratory tract disease, dermatitis, and CNS lesions. Babesia infections remain a threat to horses imported from some regions of the world. Most research activity has dealt with the development of new antiparasitic drugs. Efforts must be made to integrate these studies with observations on the bionomics of parasites in different regions and under different management conditions into more effective and less costly integrated parasite control programs. Increased research activity concerning the pathogenesis and immune response to equine parasitic infections is also necessary. A better understanding of these factors will lead to improved diagnostic, treatment, and preventative measures. Specific research objectives designed to produce short-term and long-term benefits are suggested. PMID:6383147

  12. Where are the parasites in food webs?

    PubMed Central

    2012-01-01

    This review explores some of the reasons why food webs seem to contain relatively few parasite species when compared to the full diversity of free living species in the system. At present, there are few coherent food web theories to guide scientific studies on parasites, and this review posits that the methods, directions and questions in the field of food web ecology are not always congruent with parasitological inquiry. For example, topological analysis (the primary tool in food web studies) focuses on only one of six important steps in trematode life cycles, each of which requires a stable community dynamic to evolve. In addition, these transmission strategies may also utilize pathways within the food web that are not considered in traditional food web investigations. It is asserted that more effort must be focused on parasite-centric models, and a central theme is that many different approaches will be required. One promising approach is the old energetic perspective, which considers energy as the critical resource for all organisms, and the currency of all food web interactions. From the parasitological point of view, energy can be used to characterize the roles of parasites at all levels in the food web, from individuals to populations to community. The literature on parasite energetics in food webs is very sparse, but the evidence suggests that parasite species richness is low in food webs because parasites are limited by the quantity of energy available to their unique lifestyles. PMID:23092160

  13. Parasite and host assemblages: embracing the reality will improve our knowledge of parasite transmission and virulence

    PubMed Central

    Rigaud, Thierry; Perrot-Minnot, Marie-Jeanne; Brown, Mark J. F.

    2010-01-01

    Interactions involving several parasite species (multi-parasitized hosts) or several host species (multi-host parasites) are the rule in nature. Only a few studies have investigated these realistic, but complex, situations from an evolutionary perspective. Consequently, their impact on the evolution of parasite virulence and transmission remains poorly understood. The mechanisms by which multiple infections may influence virulence and transmission include the dynamics of intrahost competition, mediation by the host immune system and an increase in parasite genetic recombination. Theoretical investigations have yet to be conducted to determine which of these mechanisms are likely to be key factors in the evolution of virulence and transmission. In contrast, the relationship between multi-host parasites and parasite virulence and transmission has seen some theoretical investigation. The key factors in these models are the trade-off between virulence across different host species, variation in host species quality and patterns of transmission. The empirical studies on multi-host parasites suggest that interspecies transmission plays a central role in the evolution of virulence, but as yet no complete picture of the phenomena involved is available. Ultimately, determining how complex host–parasite interactions impact the evolution of host–parasite relationships will require the development of cross-disciplinary studies linking the ecology of quantitative networks with the evolution of virulence. PMID:20667874

  14. Retaliatory mafia behavior by a parasitic cowbird favors host acceptance of parasitic eggs.

    PubMed

    Hoover, Jeffrey P; Robinson, Scott K

    2007-03-13

    Why do many hosts accept costly avian brood parasitism even when parasitic eggs and nestlings differ dramatically in appearance from their own? Scientists argue that evolutionary lag or equilibrium can explain this evolutionary enigma. Few, however, consider the potential of parasitic birds to enforce acceptance by destroying eggs or nestlings of hosts that eject parasitic eggs and thereby reject parasitism. This retaliatory "mafia" behavior has been reported in one species of parasitic cuckoo but never in parasitic cowbirds. Here we present experimental evidence of mafia behavior in the brown-headed cowbird (Molothrus ater), a widely distributed North American brood parasite. We manipulated ejection of cowbird eggs and cowbird access to predator-proof nests in a common host to test experimentally for mafia behavior. When cowbird access was allowed, 56% of "ejector" nests were depredated compared with only 6% of "accepter" nests. No nests were destroyed when cowbird access was always denied or when access was denied after we removed cowbird eggs, indicating that cowbirds were responsible. Nonparasitized nests were depredated at an intermediate rate (20%) when cowbirds were allowed access, suggesting that cowbirds may occasionally "farm" hosts to create additional opportunities for parasitism. Cowbirds parasitized most (85%) renests of the hosts whose nests were depredated. Ejector nests produced 60% fewer host offspring than accepter nests because of the predatory behavior attributed to cowbirds. Widespread predatory behaviors in cowbirds could slow the evolution of rejection behaviors and further threaten populations of some of the >100 species of regular cowbird hosts. PMID:17360549

  15. Potential Parasite Transmission in Multi-Host Networks Based on Parasite Sharing

    PubMed Central

    Pilosof, Shai; Morand, Serge; Krasnov, Boris R.; Nunn, Charles L.

    2015-01-01

    Epidemiological networks are commonly used to explore dynamics of parasite transmission among individuals in a population of a given host species. However, many parasites infect multiple host species, and thus multi-host networks may offer a better framework for investigating parasite dynamics. We investigated the factors that influence parasite sharing – and thus potential transmission pathways – among rodent hosts in Southeast Asia. We focused on differences between networks of a single host species and networks that involve multiple host species. In host-parasite networks, modularity (the extent to which the network is divided into subgroups of rodents that interact with similar parasites) was higher in the multi-species than in the single-species networks. This suggests that phylogeny affects patterns of parasite sharing, which was confirmed in analyses showing that it predicted affiliation of individuals to modules. We then constructed “potential transmission networks” based on the host-parasite networks, in which edges depict the similarity between a pair of individuals in the parasites they share. The centrality of individuals in these networks differed between multi- and single-species networks, with species identity and individual characteristics influencing their position in the networks. Simulations further revealed that parasite dynamics differed between multi- and single-species networks. We conclude that multi-host networks based on parasite sharing can provide new insights into the potential for transmission among hosts in an ecological community. In addition, the factors that determine the nature of parasite sharing (i.e. structure of the host-parasite network) may impact transmission patterns. PMID:25748947

  16. Parasitic Infections in Hematopoietic Stem Cell Transplantation

    PubMed Central

    Jarque, Isidro; Salavert, Miguel; Pemán, Javier

    2016-01-01

    Parasitic infections are rarely documented in hematopoietic stem cell transplant recipients. However they may be responsible for fatal complications that are only diagnosed at autopsy. Increased awareness of the possibility of parasitic diseases both in autologous and allogeneic stem cell transplant patients is relevant not only for implementing preventive measures but also for performing an early diagnosis and starting appropriate therapy for these unrecognized but fatal infectious complications in hematopoietic transplant recipients. In this review, we will focus on parasitic diseases occurring in this population especially those with major clinical relevance including toxoplasmosis, American trypanosomiasis, leishmaniasis, malaria, and strongyloidiasis, among others, highlighting the diagnosis and management in hematopoietic transplant recipients. PMID:27413527

  17. Fc receptors and immunity to parasites.

    PubMed

    Pleass, R J; Woof, J M

    2001-11-01

    Fc receptors (FcRs) are crucial in the immune system; they mediate a plethora of biological functions as diverse as antigen presentation, phagocytosis, cytotoxicity, induction of inflammatory cascades and modulation of immune responses. Parasites, in order to survive in the immunocompetent host, have devised ingenious methods to subvert this important aspect of the immune response. This article discusses the current thinking on FcRs, their role in immunity to parasites, and immune evasion strategies employed by parasites in their attempt to neutralize the important immune defense mechanisms mediated by these molecules. PMID:11872400

  18. Public health significance of intestinal parasitic infections*

    PubMed Central

    1987-01-01

    Intestinal parasitic infections are distributed virtually throughout the world, with high prevalence rates in many regions. Amoebiasis, ascariasis, hookworm infection and trichuriasis are among the ten most common infections in the world. Other parasitic infections such as abdominal angiostrongyliasis, intestinal capillariasis, and strongyloidiasis are of local or regional public health concern. The prevention and control of these infections are now more feasible than ever before owing to the discovery of safe and efficacious drugs, the improvement and simplification of some diagnostic procedures, and advances in parasite population biology. PMID:3501340

  19. Blood parasites of penguins: a critical review.

    PubMed

    Vanstreels, Ralph Eric Thijl; Braga, Érika Martins; Catão-Dias, José Luiz

    2016-07-01

    Blood parasites are considered some of the most significant pathogens for the conservation of penguins, due to the considerable morbidity and mortality they have been shown to produce in captive and wild populations of these birds. Parasites known to occur in the blood of penguins include haemosporidian protozoans (Plasmodium, Leucocytozoon, Haemoproteus), piroplamid protozoans (Babesia), kinetoplastid protozoans (Trypanosoma), spirochete bacteria (Borrelia) and nematode microfilariae. This review provides a critical and comprehensive assessment of the current knowledge on these parasites, providing an overview of their biology, host and geographic distribution, epidemiology, pathology and implications for public health and conservation. PMID:27253438

  20. Malaria Parasites Produce Volatile Mosquito Attractants

    PubMed Central

    Kelly, Megan; Su, Chih-Ying; Schaber, Chad; Crowley, Jan R.; Hsu, Fong-Fu; Carlson, John R.

    2015-01-01

    ABSTRACT The malaria parasite Plasmodium falciparum contains a nonphotosynthetic plastid organelle that possesses plant-like metabolic pathways. Plants use the plastidial isoprenoid biosynthesis pathway to produce volatile odorants, known as terpenes. In this work, we describe the volatile chemical profile of cultured malaria parasites. Among the identified compounds are several plant-like terpenes and terpene derivatives, including known mosquito attractants. We establish the molecular identity of the odorant receptors of the malaria mosquito vector Anopheles gambiae, which responds to these compounds. The malaria parasite produces volatile signals that are recognized by mosquitoes and may thereby mediate host attraction and facilitate transmission. PMID:25805727

  1. Parasitic Infections in Hematopoietic Stem Cell Transplantation.

    PubMed

    Jarque, Isidro; Salavert, Miguel; Pemán, Javier

    2016-01-01

    Parasitic infections are rarely documented in hematopoietic stem cell transplant recipients. However they may be responsible for fatal complications that are only diagnosed at autopsy. Increased awareness of the possibility of parasitic diseases both in autologous and allogeneic stem cell transplant patients is relevant not only for implementing preventive measures but also for performing an early diagnosis and starting appropriate therapy for these unrecognized but fatal infectious complications in hematopoietic transplant recipients. In this review, we will focus on parasitic diseases occurring in this population especially those with major clinical relevance including toxoplasmosis, American trypanosomiasis, leishmaniasis, malaria, and strongyloidiasis, among others, highlighting the diagnosis and management in hematopoietic transplant recipients. PMID:27413527

  2. Mansonelliasis, a neglected parasitic disease in Haiti

    PubMed Central

    Raccurt, Christian Pierre; Brasseur, Philippe; Boncy, Jacques

    2014-01-01

    Reported in Haiti as early as 1923, Mansonella ozzardi is still a neglected disease ignored by the health authorities of the country. This review is an update on the geographic distribution of the coastal foci of mansonelliasis in Haiti, the epidemiological profile and prevalence rates of microfilariae in people living in endemic areas, the clinical impact of the parasite on health and the efficiency of the transmission of the parasite among three Culicoides biting-midge species identified as vectors in Haiti. Additionally, interest in establishing a treatment programme to combat this parasite using a single dose of ivermectin is emphasised. PMID:25317697

  3. Water-Related Parasitic Diseases in China

    PubMed Central

    Lv, Shan; Tian, Li-Guang; Liu, Qin; Qian, Men-Bao; Fu, Qing; Steinmann, Peter; Chen, Jia-Xu; Yang, Guo-Jing; Yang, Kun; Zhou, Xiao-Nong

    2013-01-01

    Water-related parasitic diseases are directly dependent on water bodies for their spread or as a habitat for indispensable intermediate or final hosts. Along with socioeconomic development and improvement of sanitation, overall prevalence is declining in the China. However, the heterogeneity in economic development and the inequity of access to public services result in considerable burden due to parasitic diseases in certain areas and populations across the country. In this review, we demonstrated three aspects of ten major water-related parasitic diseases, i.e., the biology and pathogenicity, epidemiology and recent advances in research in China. General measures for diseases control and special control strategies are summarized. PMID:23685826

  4. Reduced helminth parasitism in the introduced bank vole (Myodes glareolus): More parasites lost than gained.

    PubMed

    Loxton, Karen C; Lawton, Colin; Stafford, Peter; Holland, Celia V

    2016-08-01

    Introduced species are often less parasitised compared to their native counterparts and to ecologically similar hosts in the new environment. Reduced parasitism may come about due to both the loss of original parasites and low acquisition of novel parasites. In this study we investigated the intestinal helminth parasites of the introduced bank vole (Myodes glareolus) in Ireland. Results were compared to data from other European studies and to the intestinal helminth fauna of an ecologically similar native rodent in Ireland, the wood mouse (Apodemus sylvaticus). The helminth fauna of introduced bank voles exhibited low diversity with only 3 species recovered: Aspiculuris tianjinensis; Aonchotheca murissylvatici and Taenia martis larvae. In particular, no adult parasites with indirect life-cycles were found in bank voles suggesting that indirectly transmitted parasites are less likely to establish in invasive hosts. Also, the results of this study add support to the enemy release hypothesis. PMID:27408800

  5. [Trematode parasites of Italian bats].

    PubMed

    Ricci, M

    1995-12-01

    Data are presented on bat trematodes in Italy, whose previous list included only the following five species: Plagiorchis vespertilionis, Plagiorchis asper, Mesotretes peregrinus, Prosthodendrium chilostomum, Prosthodendrium longiforme. Between 1945 and 1981, 289 bats were examined belonging to 13 species. A total of twelve trematode species were identified, nine of which are recorded for the first time in Italy: Lecithodendrium linstowi, Lecithodendrium granulosum, Lecithodendrium rotundum, Prosthodendrium herardovae, Prosthodendrium hurkovaae, Prosthodendrium parvouterus, Pycnoporus heteroporus, Matovius rhinolophi, Parabascus lepidotus. For each parasite species, hosts, localities and number of specimens/host are reported. Special attention is devoted to P. vespertilionis with description of specimens remarkably different from the type form, to L. linstowi for peculiar specimens from Rhinolophus hipposideros, and to M. rhinolophi with additions to the original description especially concerning the vitelline glands' structure. Pycnoporus macrolaimus, identified in a collection of bat trematodes of the Institute of Parasitology of the University "La Sapienza" of Rome, is also recorded for the first time in Italy. PMID:8778660

  6. Strongyloidiasis. The protean parasitic infection.

    PubMed

    Schneider, J H; Rogers, A I

    1997-09-01

    To turn a well-known phrase regarding history, those who forget to diagnose strongyloidiasis will be condemned to rediscover it. The often protean manifestations of this disease cannot be emphasized enough. The parasite's unique life cycle enables it to live for decades in an unsuspecting host, presenting with symptomatic disease only occasionally. Making a definitive diagnosis may be difficult and requires persistence. A good history should reveal whether a patient belongs to a high-risk group. The physician should strongly suspect the diagnosis when nonspecific cutaneous, pulmonary, and gastrointestinal symptoms coexist. Unexplained enteric bacteremia or meningitis may be important clues to diagnosing disseminated disease, which carries a high mortality rate. Therapy is available, and advances are being made to make it more tolerable. Follow-up for eradication is laborious yet essential: In patients at high risk for disseminated disease, invasive procedures may be warranted to prove eradication. Incomplete therapy puts the patient at further risk for significant complications in the future. PMID:9300026

  7. Parasite specialization in a unique habitat: hummingbirds as reservoirs of generalist blood parasites of Andean birds.

    PubMed

    Moens, Michaël A J; Valkiūnas, Gediminas; Paca, Anahi; Bonaccorso, Elisa; Aguirre, Nikolay; Pérez-Tris, Javier

    2016-09-01

    Understanding how parasites fill their ecological niches requires information on the processes involved in the colonization and exploitation of unique host species. Switching to hosts with atypical attributes may favour generalists broadening their niches or may promote specialization and parasite diversification as the consequence. We analysed which blood parasites have successfully colonized hummingbirds, and how they have evolved to exploit such a unique habitat. We specifically asked (i) whether the assemblage of Haemoproteus parasites of hummingbirds is the result of single or multiple colonization events, (ii) to what extent these parasites are specialized in hummingbirds or shared with other birds and (iii) how hummingbirds contribute to sustain the populations of these parasites, in terms of both prevalence and infection intensity. We sampled 169 hummingbirds of 19 species along an elevation gradient in Southern Ecuador to analyse the host specificity, diversity and infection intensity of Haemoproteus by molecular and microscopy techniques. In addition, 736 birds of 112 species were analysed to explore whether hummingbird parasites are shared with other birds. Hummingbirds hosted a phylogenetically diverse assemblage of generalist Haemoproteus lineages shared with other host orders. Among these parasites, Haemoproteus witti stood out as the most generalized. Interestingly, we found that infection intensities of this parasite were extremely low in passerines (with no detectable gametocytes), but very high in hummingbirds, with many gametocytes seen. Moreover, infection intensities of H. witti were positively correlated with the prevalence across host species. Our results show that hummingbirds have been colonized by generalist Haemoproteus lineages on multiple occasions. However, one of these generalist parasites (H. witti) seems to be highly dependent on hummingbirds, which arise as the most relevant reservoirs in terms of both prevalence and

  8. HOW WILL GLOBAL CLIMATE CHANGE AFFECT PARASITES?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Parasites are integral components of complex biotic assemblages that comprise the biosphere. Host switching correlated with episodic climate-change events are common in evolutionary and ecological time. Global climate change produces ecological perturbation, manifested in major geographical/pheno...

  9. Parasite Zoonoses and Wildlife: Emerging Issues

    PubMed Central

    Thompson, R.C. Andrew; Kutz, Susan J.; Smith, Andrew

    2009-01-01

    The role of wildlife as important sources, reservoirs and amplifiers of emerging human and domestic livestock pathogens, in addition to well recognized zoonoses of public health significance, has gained considerable attention in recent years. However, there has been little attention given to the transmission and impacts of pathogens of human origin, particularly protozoan, helminth and arthropod parasites, on wildlife. Substantial advances in molecular technologies are greatly improving our ability to follow parasite flow among host species and populations and revealing valuable insights about the interactions between cycles of transmission. Here we present several case studies of parasite emergence, or risk of emergence, in wildlife, as a result of contact with humans or anthropogenic activities. For some of these parasites, there is growing evidence of the serious consequences of infection on wildlife survival, whereas for others, there is a paucity of information about their impact. PMID:19440409

  10. Travel/Travelers and Parasitic Diseases

    MedlinePlus

    ... Taenia infection fascioliasis Vector-borne Transmission More Common malaria leishmaniasis Less Common Chagas disease lymphatic filariasis African ... source: Global Health - Division of Parasitic Diseases and Malaria Notice: Linking to a non-federal site does ...

  11. Chapter 42. Waterborne and Foodborne Parasites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter identifies the most prominent parasites in North America that are acquired through contaminated food and water including protozoa (Acanthamoeba, Naegleria, Entamoeba, Giardia, Cryptosporidium, Cystoisospora, Cyclospora, Toxoplasma, and Balantidium), nematodes (Trichinella, Angiostrongyl...

  12. Solar radiation decreases parasitism in Daphnia.

    PubMed

    Overholt, Erin P; Hall, Spencer R; Williamson, Craig E; Meikle, Claire K; Duffy, Meghan A; Cáceres, Carla E

    2012-01-01

    Climate change and variation in atmospheric ozone are influencing the intensity of ultraviolet radiation (UVR) reaching ecosystems. Changing UVR regimes, in turn, may alter epidemics of infectious disease. This possibility hinges on the sensitivity of epidemiologically relevant traits of host and parasite to UVR. We address this issue using a planktonic system (a zooplankton host, Daphnia dentifera, and its virulent fungal parasite, Metschnikowia bicuspidata). Controlled laboratory experiments, coupled with in situ field incubations of spores, revealed that quite low levels of UVR (as well as longer wavelength light) sharply reduced the infectivity of fungal spores but did not affect host susceptibility to infection. The parasite's sensitivity to solar radiation may underlie patterns in a lake survey: higher penetration of solar radiation into lakes correlated with smaller epidemics that started later in autumn (as incident sunlight declined). Thus, solar radiation, by diminishing infectivity of the parasite, may potently reduce disease. PMID:22034950

  13. [Report on a fungus parasitizing Entamoeba histolytica].

    PubMed

    Cao, C Q; Feng, Y S

    1989-01-01

    Infection of Entamoeba histolytica with chytridiaceous fungus Sphaerita was observed in some specimens obtained from a farmer and stained with iron-haematoxylin. The fungi were found in 78% of the cysts, mostly immature ones. Within the amoebae this parasite occurred singly, in groups, or in the form of a sporangium. It was located in the cytoplasm, the glycogen mass or the chromatoidal bars. In the same specimen, the parasitic fungus was also found in 18% of E. coli cysts; in 11% of E. nana cysts; while only one of 16 E. hartmanni cysts was parasitized. It is an interesting case of superimposed parasitism so far reported in China as well as a rare case of several species of amoebae being heavily involved with the same in the scientific literature. PMID:2548767

  14. Varactor diode assembly with low parasitic reactances

    NASA Technical Reports Server (NTRS)

    Dickens, L. E.

    1975-01-01

    Development of varactor diode assembly overcomes parasitic reactances of conventional varactor packages. In specially constructed assembly very high idler-frequency to signal-frequency ratios are used to obtain low-noise operation over maximum bandwidth.

  15. Parasite meningomyelitis in cats in Uruguay.

    PubMed

    Rivero, Rodolfo; Matto, Carolina; Adrien, María de Lourdes; Nan, Fernando; Bell, Todd; Gardiner, Christopher

    2011-01-01

    Two outbreaks of progressive hind limb paresis in cats (Felis catus) caused by parasitic meningomyelitis in Uruguay are reported. The case studies occurred in 2008 and 2009 respectively, in the rural areas of Fray Bentos (33° 07' 40.39'' S) and were characterized by hindquarter paralysis. This paralysis was progressive and had a chronic progression of approximately 12 months until the death or euthanasia of the animals. Clinical symptoms started with ataxia of the hindquarters with lateral side-to-side swaying and culminated in total paralysis. Two animals were sent for necropsy in 2009. The main histopathological findings were severe myelitis in the lumbar spinal cord with perivascular cuffing and white matter necrosis, severe nonsuppurative meningitis with thrombi in subarachnoid blood vessels, and intravascular presence of multiple adult parasites. From the morphological characteristics of the parasites and location in the leptomeninges, the parasite was identified as the nematode Gurltia paralysans. PMID:21961761

  16. Protein microarrays for parasite antigen discovery.

    PubMed

    Driguez, Patrick; Doolan, Denise L; Molina, Douglas M; Loukas, Alex; Trieu, Angela; Felgner, Phil L; McManus, Donald P

    2015-01-01

    The host serological profile to a parasitic infection, such as schistosomiasis, can be used to define potential vaccine and diagnostic targets. Determining the host antibody response using traditional approaches is hindered by the large number of putative antigens in any parasite proteome. Parasite protein microarrays offer the potential for a high-throughput host antibody screen to simplify this task. In order to construct the array, parasite proteins are selected from available genomic sequence and protein databases using bioinformatic tools. Selected open reading frames are PCR amplified, incorporated into a vector for cell-free protein expression, and printed robotically onto glass slides. The protein microarrays can be probed with antisera from infected/immune animals or humans and the antibody reactivity measured with fluorophore labeled antibodies on a confocal laser microarray scanner to identify potential targets for diagnosis or therapeutic or prophylactic intervention. PMID:25388117

  17. Genomics and the biology of parasites.

    PubMed

    Johnston, D A; Blaxter, M L; Degrave, W M; Foster, J; Ivens, A C; Melville, S E

    1999-02-01

    Despite the advances of modern medicine, the threat of chronic illness, disfigurement, or death that can result from parasitic infection still affects the majority of the world population, retarding economic development. For most parasitic diseases, current therapeutics often leave much to be desired in terms of administration regime, toxicity, or effectiveness and potential vaccines are a long way from market. Our best prospects for identifying new targets for drug, vaccine, and diagnostics development and for dissecting the biological basis of drug resistance, antigenic diversity, infectivity and pathology lie in parasite genome analysis, and international mapping and gene discovery initiatives are under way for a variety of protozoan and helminth parasites. These are far from ideal experimental organisms, and the influence of biological and genomic characteristics on experimental approaches is discussed, progress is reviewed and future prospects are examined. PMID:10193187

  18. A productivity model for parasitized, multibrooded songbirds

    USGS Publications Warehouse

    Powell, L.A.; Knutson, M.G.

    2006-01-01

    We present an enhancement of a simulation model to predict annual productivity for Wood Thrushes (Hylocichla mustelina) and American Redstarts (Setophaga ruticilla); the model includes effects of Brown-headed Cowbird (Molothrus ater) parasitism. We used species-specific data from the Driftless Area Ecoregion of Wisconsin, Minnesota, and Iowa to parameterize the model as a case study. The simulation model predicted annual productivity of 2.03 ?? 1.60 SD for Wood Thrushes and 1.56 ?? 1.31 SD for American Redstarts. Our sensitivity analysis showed that high parasitism lowered Wood Thrush annual productivity more than American Redstart productivity, even though parasitism affected individual nests of redstarts more severely. Annual productivity predictions are valuable for habitat managers, but productivity is not easily obtained from field studies. Our model provides a useful means of integrating complex life history parameters to predict productivity for songbirds that experience nest parasitism. ?? The Cooper Ornithological Society 2006.

  19. Parasites of the Raccoon, Procyon lotor

    USGS Publications Warehouse

    Clark, G.M.; Herman, C.M.

    1959-01-01

    At least 76 species of parasites have been reported from raccoons. These include 4 species of protozoa, 27 nematodes, 20 trematodes, 7 cestodes, 3 acanthocephala, and 15 arthropods. In many cases these represent single reports. In other cases some of the parasites are known to be of frequent occurrence and broad geographical range on the basis of several surveys that have been conducted. During the past 30 years 260 raccoons have been examined for parasites at the Patuxent Research Refuge. While most of these animals were collected on the refuge, several were from other localities in Maryland and a few from outside this state. The known distribution and occurrence of parasites of the raccoon are presented on charts and representative specimens of some of those collected at the Patuxent Research Refuge are demonstrated.

  20. DEVELOPMENT OF APTAMERS TO WATERBORNE PARASITES

    EPA Science Inventory

    The Safe Drinking Water Act Amendment of 1996 mandates that the U. S. Environmental Protection Agency (EPA) evaluate public health risks associated with drinking water contaminants to include waterborne parasites, such as Cryptosporidium and Giardia. Additionally, the Agency est...

  1. Drug repurposing and human parasitic protozoan diseases

    PubMed Central

    Andrews, Katherine T.; Fisher, Gillian; Skinner-Adams, Tina S.

    2014-01-01

    Parasitic diseases have an enormous health, social and economic impact and are a particular problem in tropical regions of the world. Diseases caused by protozoa and helminths, such as malaria and schistosomiasis, are the cause of most parasite related morbidity and mortality, with an estimated 1.1 million combined deaths annually. The global burden of these diseases is exacerbated by the lack of licensed vaccines, making safe and effective drugs vital to their prevention and treatment. Unfortunately, where drugs are available, their usefulness is being increasingly threatened by parasite drug resistance. The need for new drugs drives antiparasitic drug discovery research globally and requires a range of innovative strategies to ensure a sustainable pipeline of lead compounds. In this review we discuss one of these approaches, drug repurposing or repositioning, with a focus on major human parasitic protozoan diseases such as malaria, trypanosomiasis, toxoplasmosis, cryptosporidiosis and leishmaniasis. PMID:25057459

  2. Targeting Lysine Deacetylases (KDACs) in Parasites

    PubMed Central

    Wang, Qi; Rosa, Bruce A.; Nare, Bakela; Powell, Kerrie; Valente, Sergio; Rotili, Dante; Mai, Antonello; Marshall, Garland R.; Mitreva, Makedonka

    2015-01-01

    Due to an increasing problem of drug resistance among almost all parasites species ranging from protists to worms, there is an urgent need to explore new drug targets and their inhibitors to provide new and effective parasitic therapeutics. In this regard, there is growing interest in exploring known drug leads of human epigenetic enzymes as potential starting points to develop novel treatments for parasitic diseases. This approach of repurposing (starting with validated targets and inhibitors) is quite attractive since it has the potential to reduce the expense of drug development and accelerate the process of developing novel drug candidates for parasite control. Lysine deacetylases (KDACs) are among the most studied epigenetic drug targets of humans, and a broad range of small-molecule inhibitors for these enzymes have been reported. In this work, we identify the KDAC protein families in representative species across important classes of parasites, screen a compound library of 23 hydroxamate- or benzamide-based small molecules KDAC inhibitors, and report their activities against a range of parasitic species, including the pathogen of malaria (Plasmodium falciparum), kinetoplastids (Trypanosoma brucei and Leishmania donovani), and nematodes (Brugia malayi, Dirofilaria immitis and Haemonchus contortus). Compound activity against parasites is compared to that observed against the mammalian cell line (L929 mouse fibroblast) in order to determine potential parasite-versus-host selectivity). The compounds showed nanomolar to sub-nanomolar potency against various parasites, and some selectivity was observed within the small panel of compounds tested. The possible binding modes of the active compounds at the different protein target sites within different species were explored by docking to homology models to help guide the discovery of more selective, parasite-specific inhibitors. This current work supports previous studies that explored the use of KDAC inhibitors in

  3. Soil transmitted parasites in Qualyobia Governorate.

    PubMed

    El Fakahany, Amany F; Younis, Mohamed S; Ali, Ali El-Said; El-Ghareeb, Azza S; Omar, Rabab El Sayed

    2013-08-01

    The study determined the relation between prevalence of intestinal parasites and soil-transmitted parasites among households in Shiblanga representing a rural area of Qualyobia Governorate and Benha City representing an urban area of the same Governorate. The effect of soil's type on the intensity of parasites and to provide guidance on the prevention and control of soil transmitted parasitic infections for future studies in this field. This study was conducted at Benha City and Shiblanga village representing the urban and rural areas of Qualyobia Governorate. Geoparasites were investigated in-doors, around houses, in the fields and the streets from both areas. One hundred soil samples from Benha city and one hundred soil samples from Shiblanga village were collected .each hundred soil samples was collected in the form of: 25 samples from the fields, 25 samples in-indoor yards, 25 samples the streets, 25 samples around houses. Approximately 200 g soil was collected in plastic bags at 2-10 cm depth from different parts. Stool samples from households in same areas were collected after taken oral consent. All soil samples were screened for parasites using different parasitological methods (Zinc sulphate flotation, ether sédimentation technique, modified Baerman's apparatus and modified Berlese technique). All stool samples were examined using direct smear, formalinether concentration techniques for detection of helminthes eggs, and modified acid-fast staining for detection of protozoa. The results showed that 86/200 soil samples were contaminated with different parasites, the prevalence rate of 43%. Soil samples from Shiblanga village showed higher level of parasitic contamination (56%) and Benha city showed a lower level of contamination by different parasites (30%). Soil samples obtained from Manshiet El-Nour district, Benha revealed the highest level of parasitic contamination. While, in Shiblanga, El-Mansheya district revealed the highest level of parasitic

  4. Cytosolic superoxide dismutase can provide protection against Fasciola gigantica.

    PubMed

    Jaikua, Wipaphorn; Kueakhai, Pornanan; Chaithirayanon, Kulathida; Tanomrat, Rataya; Wongwairot, Sirima; Riengrojpitak, Suda; Sobhon, Prasert; Changklungmoa, Narin

    2016-10-01

    Superoxide dismutases (SOD), antioxidant metallo-enzymes, are a part of the first line of defense in the trematode parasites which act as the chief scavengers for reactive oxygen species (ROS). A recombinant Fasciola gigantica cytosolic SOD (FgSOD) was expressed in Escherichia coli BL21 (DE3) and used for immunizing rabbits to obtain polyclonal antibodies (anti-rFgSOD). This rabbit anti-rFgSOD reacted with the native FgSOD at a molecular weight of 17.5kDa. The FgSOD protein was expressed at high level in parenchyma, caecal epithelium and egg of the parasite. The rFgSOD reacted with antisera from rabbits infected with F. gigantica metacercariae collected at 2, 5, and 7 weeks after infection, and reacted with sera of infected mice. Anti-rFgSOD exhibited cross reactivity with the other parasites' antigens, including Eurytrema pancreaticum, Cotylophoron cotylophorum, Fischoederius cobboldi, Gastrothylax crumenifer, Paramphistomum cervi, and Setaria labiato papillosa. A vaccination was performed in imprinting control region (ICR) mice by subcutaneous injection with 50μg of rFgSOD combined with Freund's adjuvant. At 2 weeks after the second boost, mice were infected with 15 metacercariae by oral route. IgG1 and IgG2a in the immune sera were determined to indicate Th2 and Th1 immune responses. It was found that the parasite burden was reduced by 45%, and both IgG1 and IgG2a levels showed correlation with the numbers of worm recoveries. PMID:27338185

  5. Role of parasitic vaccines in integrated control of parasitic diseases in livestock

    PubMed Central

    Sharma, Neelu; Singh, Veer; Shyma, K. P.

    2015-01-01

    Parasitic infections adversely affect animal’s health and threaten profitable animal production, thus affecting the economy of our country. These infections also play a major role in the spread of zoonotic diseases. Parasitic infections cause severe morbidity and mortality in animals especially those affecting the gastrointestinal system and thus affect the economy of livestock owner by decreasing the ability of the farmer to produce economically useful animal products. Due to all these reasons proper control of parasitic infection is critically important for sustained animal production. The most common and regularly used method to control parasitic infection is chemotherapy, which is very effective but has several disadvantages like drug resistance and drug residues. Integrated approaches to control parasitic infections should be formulated including grazing management, biological control, genetic resistance of hosts, and parasitic vaccines. India ranks first in cattle and buffalo population, but the majority of livestock owners have fewer herds, so other measures like grazing management, biological control, genetic resistance of hosts are not much practical to use. The most sustainable and economical approach to control parasitic infection in our country is to vaccinate animals, although vaccines increase the initial cost, but the immunity offered by the vaccine are long lived. Thus, vaccination of animals for various clinical, chronic, subclinical parasitic infections will be a cheaper and effective alternative to control parasitic infection for long time and improve animal production. PMID:27047140

  6. Brood parasite eggs enhance egg survivorship in a multiply parasitized host

    PubMed Central

    Gloag, Ros; Fiorini, Vanina D.; Reboreda, Juan C.; Kacelnik, Alex

    2012-01-01

    Despite the costs to avian parents of rearing brood parasitic offspring, many species do not reject foreign eggs from their nests. We show that where multiple parasitism occurs, rejection itself can be costly, by increasing the risk of host egg loss during subsequent parasite attacks. Chalk-browed mockingbirds (Mimus saturninus) are heavily parasitized by shiny cowbirds (Molothrus bonariensis), which also puncture eggs in host nests. Mockingbirds struggle to prevent cowbirds puncturing and laying, but seldom remove cowbird eggs once laid. We filmed cowbird visits to nests with manipulated clutch compositions and found that mockingbird eggs were more likely to escape puncture the more cowbird eggs accompanied them in the clutch. A Monte Carlo simulation of this ‘dilution effect’, comparing virtual hosts that systematically either reject or accept parasite eggs, shows that acceptors enjoy higher egg survivorship than rejecters in host populations where multiple parasitism occurs. For mockingbirds or other hosts in which host nestlings fare well in parasitized broods, this benefit might be sufficient to offset the fitness cost of rearing parasite chicks, making egg acceptance evolutionarily stable. Thus, counterintuitively, high intensities of parasitism might decrease or even reverse selection pressure for host defence via egg rejection. PMID:22158956

  7. Parasitic rheumatism presenting as rheumatoid arthritis.

    PubMed

    Burnstein, S L; Liakos, S

    1983-06-01

    A symmetrical polyarthritis with low titer positive rheumatoid factor occurred in a young man who also complained of chronic diarrhea after returning from Vietnam. Endolimax nana grew on stool culture. Both the patient's diarrhea and arthritis responded effectively to therapy with metronidazole. The diagnosis of parasitic rheumatism was made in retrospect. Diagnostic consideration should be given to this entity in patients with unusual arthropathies, particularly if they have stayed in an endemic parasitic country and have gastrointestinal symptoms. PMID:6604161

  8. Using fat to turbo-charge intracellular parasite growth.

    PubMed

    McConville, Malcolm J

    2014-12-10

    Early during infection, the malaria parasite invades liver cells and undergoes robust replication, generating thousands of new parasites within days. In this issue of Cell Host & Microbe, Itoe et al. (2014) show that parasite replication in the liver depends on the synthesis of host bulk phospholipids, which are incorporated into the expanding parasite and surrounding vacuolar membranes. PMID:25498341

  9. Evolution of parasitism along convergent lines: from ecology to genomics.

    PubMed

    Poulin, Robert; Randhawa, Haseeb S

    2015-02-01

    SUMMARY From hundreds of independent transitions from a free-living existence to a parasitic mode of life, separate parasite lineages have converged over evolutionary time to share traits and exploit their hosts in similar ways. Here, we first summarize the evidence that, at a phenotypic level, eukaryotic parasite lineages have all converged toward only six general parasitic strategies: parasitoid, parasitic castrator, directly transmitted parasite, trophically transmitted parasite, vector-transmitted parasite or micropredator. We argue that these strategies represent adaptive peaks, with the similarities among unrelated taxa within any strategy extending to all basic aspects of host exploitation and transmission among hosts and transcending phylogenetic boundaries. Then, we extend our examination of convergent patterns by looking at the evolution of parasite genomes. Despite the limited taxonomic coverage of sequenced parasite genomes currently available, we find some evidence of parallel evolution among unrelated parasite taxa with respect to genome reduction or compaction, and gene losses or gains. Matching such changes in parasite genomes with the broad phenotypic traits that define the convergence of parasites toward only six strategies of host exploitation is not possible at present. Nevertheless, as more parasite genomes become available, we may be able to detect clear trends in the evolution of parasitic genome architectures representing true convergent adaptive peaks, the genomic equivalents of the phenotypic strategies used by all parasites. PMID:24229807

  10. The host-parasite relationship in neosporosis.

    PubMed

    Hemphill, A

    1999-01-01

    Neospora caninum is an apicomplexan parasite which invades many different cell types and tissues. It causes neosporosis, namely stillbirth and abortion in cattle and neuromuscular disease in dogs, and has been found in several other animal species. N. caninum is closely related to Toxoplasma gondii, and controversial opinions exist with respect to its phylogenetical status. Initially, two stages of N. caninum had been identified, namely asexually proliferating tachyzoites and bradyzoites. The sexually produced stage of this parasite, oocysts containing sporozoites, has been found only recently. In order to answer the many open questions regarding its basic biology and its relationship with the host, a number of diagnostic tools have been developed. These techniques are based on the detection of antibodies against parasites in body fluids, the direct visualization of the parasite within tissue samples by immunohistochemistry, or the specific amplification of parasite DNA by PCR. Other studies have been aiming at the identification of specific antigenic components of N. caninum, and the molecular and functional characterization of these antigens with respect to the cell biology of the parasite. Clearly, molecular approaches will also be used increasingly to elucidate the immunological and pathogenetic events during infection, but also to prepare potential new immunotherapeutic tools for future vaccination against N. caninum infection. PMID:10214690

  11. Prevalence of gastrointestinal parasites in working horses.

    PubMed

    Tavassoli, M; Dalir-Naghadeh, B; Esmaeili-Sani, S

    2010-01-01

    Fecal samples for detection of gastrointestinal parasites were collected from 221 working horses from September 2002 to May 2003 from 14 villages in Urmia, North West of Iran. Fecal samples of 46 horses (20.8%) were negative for parasite eggs or oocysts. One hundred and seventy five positive horses (48.9%) were infected with a single parasite type and 49 (22.2%) and 18 (8.1%) of horses had multiple infections with two and three parasites, respectively. The highest prevalence and intensity rate belonged to small strongyles. The overall prevalence of intestinal parasites eggs and oocyst in the positive horses were: strongyles 72.9%, Oxyuris equi 22.6%, Parascaris equorum 12.2%, Anoplocephalidae 6.3%, Fasciola spp. 3.2% and Eimeria leuckarti 0.5%. Larval identification showed that small strongyle larvae were most frequent (97.6%) followed by Strongylus edentatus (22.6%), S. equinus (18.5%) and S. vulgaris (6.5%). This study suggests that the high rate of infection with gastrointestinal parasites could contribute to low performance and life expectancy of working horses in the region. PMID:20731187

  12. Review of Parasitic Zoonoses in Egypt

    PubMed Central

    Youssef, Ahmed I.; Uga, Shoji

    2014-01-01

    This review presents a comprehensive picture of the zoonotic parasitic diseases in Egypt, with particular reference to their relative prevalence among humans, animal reservoirs of infection, and sources of human infection. A review of the available literature indicates that many parasitic zoonoses are endemic in Egypt. Intestinal infections of parasitic zoonoses are widespread and are the leading cause of diarrhea, particularly among children and residents of rural areas. Some parasitic zoonoses are confined to specific geographic areas in Egypt, such as cutaneous leishmaniasis and zoonotic babesiosis in the Sinai. Other areas have a past history of a certain parasitic zoonoses, such as visceral leishmaniasis in the El-Agamy area in Alexandria. As a result of the implementation of control programs, a marked decrease in the prevalence of other zoonoses, such as schistosomiasis and fascioliasis has been observed. Animal reservoirs of parasitic zoonoses have been identified in Egypt, especially in rodents, stray dogs and cats, as well as vectors, typically mosquitoes and ticks, which constitute potential risks for disease transmission. Prevention and control programs against sources and reservoirs of zoonoses should be planned by public health and veterinary officers based on reliable information from systematic surveillance. PMID:24808742

  13. Role of cholesterol in parasitic infections

    PubMed Central

    Bansal, Devendra; Bhatti, Harinderpal Singh; Sehgal, Rakesh

    2005-01-01

    The requirement of cholesterol for internalization of eukaryotic pathogens like protozoa (Leishmaniasis, Malaria and Toxoplasmosis) and the exchange of cholesterol along with other metabolites during reproduction in Schistosomes (helminths) under variable circumstances are poorly understood. In patients infected with some other helminthes, alterations in the lipid profile have been observed. Also, the mechanisms involved in lipid changes especially in membrane proteins related to parasite infections remain uncertain. Present review of literature shows that parasites induce significant changes in lipid parameters, as has been shown in the in vitro study where substitution of serum by lipid/cholesterol in medium and in experimental models (in vivo). Thus changes in lipid profile occur in patients having active infections with most of the parasites. Membrane proteins are probably involved in such reactions. All parasites may be metabolising cholesterol, but the exact relationship with pathogenic mechanism is not clear. So far, studies suggest that there may be some factors or enzymes, which allow the parasite to breakup and consume lipid/cholesterol. Further studies are needed for better understanding of the mechanisms involved in vivo. The present review analysis the various studies till date and the role of cholesterol in pathogenesis of different parasitic infections. PMID:15882457

  14. Dynamic analysis of a parasite population model

    NASA Astrophysics Data System (ADS)

    Sibona, G. J.; Condat, C. A.

    2002-03-01

    We study the dynamics of a model that describes the competitive interaction between an invading species (a parasite) and its antibodies in an living being. This model was recently used to examine the dynamical competition between Tripanosoma cruzi and its antibodies during the acute phase of Chagas' disease. Depending on the antibody properties, the model yields three types of outcomes, corresponding, respectively, to healing, chronic disease, and host death. Here, we study the dynamics of the parasite-antibody interaction with the help of simulations, obtaining phase trajectories and phase diagrams for the system. We show that, under certain conditions, the size of the parasite inoculation can be crucial for the infection outcome and that a retardation in the stimulated production of an antibody species may result in the parasite gaining a definitive advantage. We also find a criterion for the relative sizes of the parameters that are required if parasite-generated decoys are indeed to help the invasion. Decoys may also induce a qualitatively different outcome: a limit cycle for the antibody-parasite population phase trajectories.

  15. Eaten alive: cannibalism is enhanced by parasites.

    PubMed

    Bunke, Mandy; Alexander, Mhairi E; Dick, Jaimie T A; Hatcher, Melanie J; Paterson, Rachel; Dunn, Alison M

    2015-03-01

    Cannibalism is ubiquitous in nature and especially pervasive in consumers with stage-specific resource utilization in resource-limited environments. Cannibalism is thus influential in the structure and functioning of biological communities. Parasites are also pervasive in nature and, we hypothesize, might affect cannibalism since infection can alter host foraging behaviour. We investigated the effects of a common parasite, the microsporidian Pleistophora mulleri, on the cannibalism rate of its host, the freshwater amphipod Gammarus duebeni celticus. Parasitic infection increased the rate of cannibalism by adults towards uninfected juvenile conspecifics, as measured by adult functional responses, that is, the rate of resource uptake as a function of resource density. This may reflect the increased metabolic requirements of the host as driven by the parasite. Furthermore, when presented with a choice, uninfected adults preferred to cannibalize uninfected rather than infected juvenile conspecifics, probably reflecting selection pressure to avoid the risk of parasite acquisition. By contrast, infected adults were indiscriminate with respect to infection status of their victims, probably owing to metabolic costs of infection and the lack of risk as the cannibals were already infected. Thus parasitism, by enhancing cannibalism rates, may have previously unrecognized effects on stage structure and population dynamics for cannibalistic species and may also act as a selective pressure leading to changes in resource use. PMID:26064614

  16. Eaten alive: cannibalism is enhanced by parasites

    PubMed Central

    Bunke, Mandy; Alexander, Mhairi E.; Dick, Jaimie T. A.; Hatcher, Melanie J.; Paterson, Rachel; Dunn, Alison M.

    2015-01-01

    Cannibalism is ubiquitous in nature and especially pervasive in consumers with stage-specific resource utilization in resource-limited environments. Cannibalism is thus influential in the structure and functioning of biological communities. Parasites are also pervasive in nature and, we hypothesize, might affect cannibalism since infection can alter host foraging behaviour. We investigated the effects of a common parasite, the microsporidian Pleistophora mulleri, on the cannibalism rate of its host, the freshwater amphipod Gammarus duebeni celticus. Parasitic infection increased the rate of cannibalism by adults towards uninfected juvenile conspecifics, as measured by adult functional responses, that is, the rate of resource uptake as a function of resource density. This may reflect the increased metabolic requirements of the host as driven by the parasite. Furthermore, when presented with a choice, uninfected adults preferred to cannibalize uninfected rather than infected juvenile conspecifics, probably reflecting selection pressure to avoid the risk of parasite acquisition. By contrast, infected adults were indiscriminate with respect to infection status of their victims, probably owing to metabolic costs of infection and the lack of risk as the cannibals were already infected. Thus parasitism, by enhancing cannibalism rates, may have previously unrecognized effects on stage structure and population dynamics for cannibalistic species and may also act as a selective pressure leading to changes in resource use. PMID:26064614

  17. Stress and sex in malaria parasites

    PubMed Central

    Carter, Lucy M.; Kafsack, Björn F.C.; Llinás, Manuel; Mideo, Nicole; Pollitt, Laura C.; Reece, Sarah E.

    2013-01-01

    For vector-borne parasites such as malaria, how within- and between-host processes interact to shape transmission is poorly understood. In the host, malaria parasites replicate asexually but for transmission to occur, specialized sexual stages (gametocytes) must be produced. Despite the central role that gametocytes play in disease transmission, explanations of why parasites adjust gametocyte production in response to in-host factors remain controversial. We propose that evolutionary theory developed to explain variation in reproductive effort in multicellular organisms, provides a framework to understand gametocyte investment strategies. We examine why parasites adjust investment in gametocytes according to the impact of changing conditions on their in-host survival. We then outline experiments required to determine whether plasticity in gametocyte investment enables parasites to maintain fitness in a variable environment. Gametocytes are a target for anti-malarial transmission-blocking interventions so understanding plasticity in investment is central to maximizing the success of control measures in the face of parasite evolution. PMID:24481194

  18. [Laboratory diagnosis of pseudoparasites, artifacts and parasitic delusions].

    PubMed

    Podhorský, Martin

    2011-06-01

    Common practice in a diagnostic parasitology laboratory involves distinguishing parasitic organisms from various artifacts. Artifacts mean pseudoparasites, supposed parasites and parasitic delusions. Pseudoparasites include undigested leftovers or coincidentally or purposely ingested nonparasitic organisms or their parts. Supposed parasites are wild organisms which were incorrectly identified as the components of faeces. In parasitic delusions, it is impossible to find any kind of parasites while patients describe imaginary parasites in detail. All the above categories of nonparasitic findings including case reports are described and discussed in the article. PMID:21780030

  19. [Treatment of parasitic liver diseases].

    PubMed

    Lecuna, V

    1989-01-01

    Most of primary and secondary parasitic liver diseases, at present can be property treated with drugs. Venezuelan pharmaceutic market has some peculiarities that have determined the disappearance from the market of many drugs such as emetine, thiabendazole, quinacrine and niclosamide. Diloxanide never appeared. Venezuela has no commercial international treatises that protect international patents in the pharmaceutical area. In addition, government regulation of cost of drugs is very strict. This is particularly true with old drugs (such as emetine or quinacrine) which had such a low price that is non-commercial for the maker of the drug, usually a large transnational, and is withdrawn from the market. Flexibility of prices is quite easy for new antibiotics which are very expensive. Frequently small national companies import the drug from Italy and Japan which sell the drug independently from international treats. Such companies frequently produce the drug for the government social system, but are unreliable and also frequently they withdraw the drug a variable period of time. The government, through the Ministry of Public Health administer free treatment with drugs for malaria, tuberculosis and leprosy. The severe economic crisis of the country has severely impaired the preventive programs and there is an increase of malaria due to gold mining in the south of the country and falciparum chloroquine resistance and an increase of schistosomiasis in a previous free area. Also administration of drugs for malaria has been severely impaired, mainly for economic reasons. The establishment of a National Government Laboratory is an old (as far as 1946) political goal, but has remained in the political intention.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2535455

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

    PubMed

    Poulin, Robert

    2011-01-01

    Parasitic organisms account for a large portion of living species. They have arisen on multiple independent occasions in many phyla, and thus encompass a huge biological diversity. This review uses several lines of evidence to argue that this vast diversity can be reduced to a few evolutionary end points that transcend phylogenetic boundaries. These represent peaks in the adaptive landscape reached independently by different lineages undergoing convergent evolution. Among eukaryotic parasites living in or on animals, six basic parasitic strategies are identified based on the number of hosts used per parasite generation, the fitness loss incurred by the host, and the transmission routes used by the parasites. They are parasitoids, parasitic castrators, directly transmitted parasites, trophically transmitted parasites, vector-transmitted parasites and micropredators. These show evidence of convergence in morphology, physiology, reproduction, life cycles and transmission patterns. Parasite-host body size ratios, and the relationship between virulence and intensity of infection, are also associated with the different parasitic strategies, but not consistently so. At the population level, patterns of parasite distribution among hosts are not uniform across all parasitic strategies, but are distinctly different for parasitoids and castrators than for other parasites. To demonstrate that the above six strategies defined for animal parasites are universal, comparisons are made with parasites of plants, in particular, plant-parasitic nematodes and parasitic angiosperms; these are shown to follow the same evolutionary trajectories seen among animal parasites, despite huge physiological and ecological differences between animals and plants. Beyond demonstrating the inevitable convergence of disparate lineages across biological hyperspace towards a limited set of adaptive strategies, this synthesis also provides a unifying framework for the study of parasitism. PMID:21295676

  1. Developmental Stage of Parasites Influences the Structure of Fish-Parasite Networks

    PubMed Central

    Bellay, Sybelle; de Oliveira, Edson Fontes; Almeida-Neto, Mário; Lima Junior, Dilermando Pereira; Takemoto, Ricardo Massato; Luque, José Luis

    2013-01-01

    Specialized interactions tend to be more common in systems that require strong reciprocal adaptation between species, such as those observed between parasites and hosts. Parasites exhibit a high diversity of species and life history strategies, presenting host specificity which increases the complexity of these antagonistic systems. However, most studies are limited to the description of interactions between a few parasite and host species, which restricts our understanding of these systems as a whole. We investigated the effect of the developmental stage of the parasite on the structure of 30 metazoan fish-parasite networks, with an emphasis on the specificity of the interactions, connectance and modularity. We assessed the functional role of each species in modular networks and its interactions within and among the modules according to the developmental stage (larval and adult) and taxonomic group of the parasites. We observed that most parasite and host species perform a few interactions but that parasites at the larval stage tended to be generalists, increasing the network connectivity within and among modules. The parasite groups did not differ among each other in the number of interactions within and among the modules when considering only species at the larval stage. However, the same groups of adult individuals differed from each other in their interaction patterns, which were related to variations in the degree of host specificity at this stage. Our results show that the interaction pattern of fishes with parasites, such as acanthocephalans, cestodes, digeneans and nematodes, is more closely associated with their developmental stage than their phylogenetic history. This finding corroborates the hypothesis that the life history of parasites results in adaptations that cross phylogenetic boundaries. PMID:24124506

  2. Zoonotic foodborne parasites and their surveillance.

    PubMed

    Murrell, K D

    2013-08-01

    Humans suffer from several foodborne helminth zoonotic diseases, some of which can be deadly (e.g., trichinellosis, cerebral cysticercosis) while others are chronic and cause only mild illness (e.g., intestinal taeniosis). The route of infection is normally consumption of the parasite's natural host as a human food item (e.g., meat). The risk for infection with these parasites is highest wherever people have an inadequate knowledge of infection and hygiene, poor animal husbandry practices, and unsafe management and disposal of human and animal waste products. The design of surveillance and control strategies for the various foodborne parasite species, and the involvement of veterinary and public health agencies, vary considerably because of the different life cycles of these parasites, and epidemiological features. Trichinella spiralis, which causes most human trichinellosis, is acquired from the consumption of pork, although increasingly cases occur from eating wild game. For cysticercosis, however, the only sources for human infection are pork (Taenia solium) or beef (T. saginata). The chief risk factor for infection of humans with these parasites is the consumption of meat that has been inadequately prepared. For the pig or cow, however, the risk factors are quite different between Trichinella and Taenia. For T. spiralis the major source of infection of pigs is exposure to infected animal meat (which carries the infective larval stage), while for both Taenia species it is human faecal material contaminated with parasite eggs shed by the adult intestinal stage of the tapeworm. Consequently, the means for preventing exposure of pigs and cattle to infective stages of T. spiralis, T. solium, and T. saginata vary markedly, especially the requirements for ensuring the biosecurity of these animals at the farm. The surveillance strategies and methods required for these parasites in livestock are discussed, including the required policy-level actions and the necessary

  3. Host-parasite interactions that guide red blood cell invasion by malaria parasites

    PubMed Central

    Paul, Aditya S.; Egan, Elizabeth S.; Duraisingh, Manoj T.

    2015-01-01

    Purpose of Review Malaria is caused by the infection and proliferation of parasites from the genus Plasmodium in red blood cells (RBCs). A free Plasmodium parasite, or merozoite, released from an infected RBC must invade another RBC host cell to sustain a blood-stage infection. Here, we review recent advances on RBC invasion by Plasmodium merozoites, focusing on specific molecular interactions between host and parasite. Recent findings Recent work highlights the central role of host-parasite interactions at virtually every stage of RBC invasion by merozoites. Biophysical experiments have for the first time measured the strength of merozoite-RBC attachment during invasion. For P. falciparum, there have been many key insights regarding the invasion ligand PfRh5 in particular, including its influence on host species tropism, a co-crystal structure with its RBC receptor basigin, and its suitability as a vaccine target. For P. vivax, researchers identified the origin and emergence of the parasite from Africa, demonstrating a natural link to the Duffy-negative RBC variant in African populations. For the simian parasite P. knowlesi, zoonotic invasion into human cells is linked to RBC age, which has implications for parasitemia during an infection and thus malaria. Summary New studies of the molecular and cellular mechanisms governing RBC invasion by Plasmodium parasites have shed light on various aspects of parasite biology and host cell tropism; and indicate opportunities for malaria control. PMID:25767956

  4. Host-Parasite Interactions and Purifying Selection in a Microsporidian Parasite of Honey Bees.

    PubMed

    Huang, Qiang; Chen, Yan Ping; Wang, Rui Wu; Cheng, Shang; Evans, Jay D

    2016-01-01

    To clarify the mechanisms of Nosema ceranae parasitism, we deep-sequenced both honey bee host and parasite mRNAs throughout a complete 6-day infection cycle. By time-series analysis, 1122 parasite genes were significantly differently expressed during the reproduction cycle, clustering into 4 expression patterns. We found reactive mitochondrial oxygen species modulator 1 of the host to be significantly down regulated during the entire infection period. Our data support the hypothesis that apoptosis of honey bee cells was suppressed during infection. We further analyzed genome-wide genetic diversity of this parasite by comparing samples collected from the same site in 2007 and 2013. The number of SNP positions per gene and the proportion of non-synonymous substitutions per gene were significantly reduced over this time period, suggesting purifying selection on the parasite genome and supporting the hypothesis that a subset of N. ceranae strains might be dominating infection. PMID:26840596

  5. Host-Parasite Interactions and Purifying Selection in a Microsporidian Parasite of Honey Bees

    PubMed Central

    Huang, Qiang; Chen, Yan Ping; Wang, Rui Wu; Cheng, Shang; Evans, Jay D.

    2016-01-01

    To clarify the mechanisms of Nosema ceranae parasitism, we deep-sequenced both honey bee host and parasite mRNAs throughout a complete 6-day infection cycle. By time-series analysis, 1122 parasite genes were significantly differently expressed during the reproduction cycle, clustering into 4 expression patterns. We found reactive mitochondrial oxygen species modulator 1 of the host to be significantly down regulated during the entire infection period. Our data support the hypothesis that apoptosis of honey bee cells was suppressed during infection. We further analyzed genome-wide genetic diversity of this parasite by comparing samples collected from the same site in 2007 and 2013. The number of SNP positions per gene and the proportion of non-synonymous substitutions per gene were significantly reduced over this time period, suggesting purifying selection on the parasite genome and supporting the hypothesis that a subset of N. ceranae strains might be dominating infection. PMID:26840596

  6. Parasitic diseases in marine cage culture--an example of experimental evolution of parasites?

    PubMed

    Nowak, Barbara F

    2007-05-01

    Rapid development of fish culture in marine cages has been associated with an emergence of parasitic diseases. There is a general trend to an increase in infections with ectoparasites with direct life cycles and a reduced diversity of parasites in aquaculture. Some mariculture creates conditions that are similar to serial passage experiments, which are used to study adaptation during experimental evolution of pathogens. In particular, increased density of fish, repeated introduction of naive hosts, homogenous host populations, fast growth and a potential decrease in genetic diversity are attributes of both aquaculture and serial passage experiments. Some free-living organisms, for example Neoparamoeba spp. and Uronema spp. parasitise fish in culture, but have not been reported from wild populations. Farming fish in marine cages can increase the risk of outbreaks of parasitic diseases, including those caused by opportunistic parasites. However, aquaculture has the potential to control parasitic diseases through selective breeding, vaccination and general fish health management. PMID:17316650

  7. The Effect and Relative Importance of Neutral Genetic Diversity for Predicting Parasitism Varies across Parasite Taxa

    PubMed Central

    Ruiz-López, María José; Monello, Ryan J.; Gompper, Matthew E.; Eggert, Lori S.

    2012-01-01

    Understanding factors that determine heterogeneity in levels of parasitism across individuals is a major challenge in disease ecology. It is known that genetic makeup plays an important role in infection likelihood, but the mechanism remains unclear as does its relative importance when compared to other factors. We analyzed relationships between genetic diversity and macroparasites in outbred, free-ranging populations of raccoons (Procyon lotor). We measured heterozygosity at 14 microsatellite loci and modeled the effects of both multi-locus and single-locus heterozygosity on parasitism using an information theoretic approach and including non-genetic factors that are known to influence the likelihood of parasitism. The association of genetic diversity and parasitism, as well as the relative importance of genetic diversity, differed by parasitic group. Endoparasite species richness was better predicted by a model that included genetic diversity, with the more heterozygous hosts harboring fewer endoparasite species. Genetic diversity was also important in predicting abundance of replete ticks (Dermacentor variabilis). This association fit a curvilinear trend, with hosts that had either high or low levels of heterozygosity harboring fewer parasites than those with intermediate levels. In contrast, genetic diversity was not important in predicting abundance of non-replete ticks and lice (Trichodectes octomaculatus). No strong single-locus effects were observed for either endoparasites or replete ticks. Our results suggest that in outbred populations multi-locus diversity might be important for coping with parasitism. The differences in the relationships between heterozygosity and parasitism for the different parasites suggest that the role of genetic diversity varies with parasite-mediated selective pressures. PMID:23049796

  8. Retaliatory mafia behavior by a parasitic cowbird favors host acceptance of parasitic eggs

    PubMed Central

    Hoover, Jeffrey P.; Robinson, Scott K.

    2007-01-01

    Why do many hosts accept costly avian brood parasitism even when parasitic eggs and nestlings differ dramatically in appearance from their own? Scientists argue that evolutionary lag or equilibrium can explain this evolutionary enigma. Few, however, consider the potential of parasitic birds to enforce acceptance by destroying eggs or nestlings of hosts that eject parasitic eggs and thereby reject parasitism. This retaliatory “mafia” behavior has been reported in one species of parasitic cuckoo but never in parasitic cowbirds. Here we present experimental evidence of mafia behavior in the brown-headed cowbird (Molothrus ater), a widely distributed North American brood parasite. We manipulated ejection of cowbird eggs and cowbird access to predator-proof nests in a common host to test experimentally for mafia behavior. When cowbird access was allowed, 56% of “ejector” nests were depredated compared with only 6% of “accepter” nests. No nests were destroyed when cowbird access was always denied or when access was denied after we removed cowbird eggs, indicating that cowbirds were responsible. Nonparasitized nests were depredated at an intermediate rate (20%) when cowbirds were allowed access, suggesting that cowbirds may occasionally “farm” hosts to create additional opportunities for parasitism. Cowbirds parasitized most (85%) renests of the hosts whose nests were depredated. Ejector nests produced 60% fewer host offspring than accepter nests because of the predatory behavior attributed to cowbirds. Widespread predatory behaviors in cowbirds could slow the evolution of rejection behaviors and further threaten populations of some of the >100 species of regular cowbird hosts. PMID:17360549

  9. Fighting fish parasites with photodynamically active chlorophyllin.

    PubMed

    Häder, D-P; Schmidl, J; Hilbig, R; Oberle, M; Wedekind, H; Richter, P

    2016-06-01

    Water-soluble chlorophyll (chlorophyllin) was used in a phototoxic reaction against a number of fish ectoparasites such as Ichtyobodo, Dactylogyrus, Trichodina, and Argulus. Chlorophyllin is applied to the water at concentrations of several micrograms per milliliter for a predefined incubation time, and afterwards, the parasites are exposed to simulated solar radiation. Application in the dark caused only little damage to the parasites; likewise, light exposure without the addition of the photosensitizer was ineffective. In Ichthyobodo, 2 μg/mL proved sufficient with subsequent simulated solar radiation to almost quantitatively kill the parasites, while in Dactylogyrus, a concentration of about 6 μg/mL was necessary. The LD50 value for this parasite was 1.02 μg/mL. Trichodina could be almost completely eliminated at 2 μg/mL. Only in the parasitic crustacean Argulus, no killing could be achieved by a photodynamic reaction using chlorophyllin. Chlorophyllin is non-toxic, biodegradable, and can be produced at low cost. Therefore, we propose that chlorophyllin (or other photodynamic substances) are a possible effective countermeasure against several ectoparasites in ponds and aquaculture since chemical remedies are either forbidden and/or ineffective. PMID:26936032

  10. Parasitic diarrheal disease: drug development and targets

    PubMed Central

    Azam, Amir; Peerzada, Mudasir N.; Ahmad, Kamal

    2015-01-01

    Diarrhea is the manifestation of gastrointestinal infection and is one of the major causes of mortality and morbidity specifically among the children of less than 5 years age worldwide. Moreover, in recent years there has been a rise in the number of reports of intestinal infections continuously in the industrialized world. These are largely related to waterborne and food borne outbreaks. These occur by the pathogenesis of both prokaryotic and eukaryotic organisms like bacteria and parasites. The parasitic intestinal infection has remained mostly unexplored and under assessed in terms of therapeutic development. The lack of new drugs and the risk of resistance have led us to carry out this review on drug development for parasitic diarrheal diseases. The major focus has been depicted on commercially available drugs, currently synthesized active heterocyclic compounds and unique drug targets, that are vital for the existence and growth of the parasites and can be further exploited for the search of therapeutically active anti-parasitic agents. PMID:26617574

  11. Malaria: targeting parasite and host cell kinomes.

    PubMed

    Doerig, Christian; Abdi, Abdirahman; Bland, Nicholas; Eschenlauer, Sylvain; Dorin-Semblat, Dominique; Fennell, Clare; Halbert, Jean; Holland, Zoe; Nivez, Marie-Paule; Semblat, Jean-Philippe; Sicard, Audrey; Reininger, Luc

    2010-03-01

    Malaria still remains one of the deadliest infectious diseases, and has a tremendous morbidity and mortality impact in the developing world. The propensity of the parasites to develop drug resistance, and the relative reluctance of the pharmaceutical industry to invest massively in the developments of drugs that would offer only limited marketing prospects, are major issues in antimalarial drug discovery. Protein kinases (PKs) have become a major family of targets for drug discovery research in a number of disease contexts, which has generated considerable resources such as kinase-directed libraries and high throughput kinase inhibition assays. The phylogenetic distance between malaria parasites and their human host translates into important divergences in their respective kinomes, and most Plasmodium kinases display atypical properties (as compared to mammalian PKs) that can be exploited towards selective inhibition. Here, we discuss the taxon-specific kinases possessed by malaria parasites, and give an overview of target PKs that have been validated by reverse genetics, either in the human malaria parasite Plasmodium falciparum or in the rodent model Plasmodium berghei. We also briefly allude to the possibility of attacking Plasmodium through the inhibition of human PKs that are required for survival of this obligatory intracellular parasite, and which are targets for other human diseases. PMID:19840874

  12. The comparative ecology and biogeography of parasites

    PubMed Central

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

    2011-01-01

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

  13. Evaluation of the role of galectins in parasite immunity.

    PubMed

    Preston, Sarah; Dunphy, Jillian; Beddoe, Travis; Meeusen, Els; Young, Anna

    2015-01-01

    Galectin-11 and galectin-14 are ruminant galectins involved in parasitic infections. Although their roles in parasite immunity are still being elucidated, its appears that their functions are parasite specific. In gastrointestinal infections with the nematode Haemonchus contortus, both galectin-11 and galectin-14 appear to be protective. However, in a chronic infection of liver fluke, Fasciola hepatica, these galectins may aid parasite survival. This chapter discusses the methods designed to study parasitic infections in sheep, which have provided us with insight into the functions of galectin-11 and galectin-14 during host-parasite interactions. These methods include parasite cultivation and infection, galectin staining of host and parasite tissue, surface staining of parasites with recombinant galectins and in vitro assays to monitor the effect of galectins on larval development. PMID:25253154

  14. Comparing mechanisms of host manipulation across host and parasite taxa

    USGS Publications Warehouse

    Lafferty, Kevin D.; Shaw, Jenny C.

    2013-01-01

    Parasites affect host behavior in several ways. They can alter activity, microhabitats or both. For trophically transmitted parasites (the focus of our study), decreased activity might impair the ability of hosts to respond to final-host predators, and increased activity and altered microhabitat choice might increase contact rates between hosts and final-host predators. In an analysis of trophically transmitted parasites, more parasite groups altered activity than altered microhabitat choice. Parasites that infected vertebrates were more likely to impair the host’s reaction to predators, whereas parasites that infected invertebrates were more likely to increase the host’s contact with predators. The site of infection might affect how parasites manipulate their hosts. For instance, parasites in the central nervous system seem particularly suited to manipulating host behavior. Manipulative parasites commonly occupy the body cavity, muscles and central nervous systems of their hosts. Acanthocephalans in the data set differed from other taxa in that they occurred exclusively in the body cavity of invertebrates. In addition, they were more likely to alter microhabitat choice than activity. Parasites in the body cavity (across parasite types) were more likely to be associated with increased host contact with predators. Parasites can manipulate the host through energetic drain, but most parasites use more sophisticated means. For instance, parasites target four physiological systems that shape behavior in both invertebrates and vertebrates: neural, endocrine, neuromodulatory and immunomodulatory. The interconnections between these systems make it difficult to isolate specific mechanisms of host behavioral manipulation.

  15. Parasites and marine invasions: Ecological and evolutionary perspectives

    NASA Astrophysics Data System (ADS)

    Goedknegt, M. Anouk; Feis, Marieke E.; Wegner, K. Mathias; Luttikhuizen, Pieternella C.; Buschbaum, Christian; Camphuysen, Kees (C. J.); van der Meer, Jaap; Thieltges, David W.

    2016-07-01

    Worldwide, marine and coastal ecosystems are heavily invaded by introduced species and the potential role of parasites in the success and impact of marine invasions has been increasingly recognized. In this review, we link recent theoretical developments in invasion ecology with empirical studies from marine ecosystems in order to provide a conceptual framework for studying the role of parasites and their hosts in marine invasions. Based on an extensive literature search, we identified six mechanisms in which invaders directly or indirectly affect parasite and host populations and communities: I) invaders can lose some or all of their parasites during the invasion process (parasite release or reduction), often causing a competitive advantage over native species; II) invaders can also act as a host for native parasites, which may indirectly amplify the parasite load of native hosts (parasite spillback); III) invaders can also be parasites themselves and be introduced without needing co-introduction of the host (introduction of free-living infective stages); IV) alternatively, parasites may be introduced together with their hosts (parasite co-introduction with host); V) consequently, these co-introduced parasites can sometimes also infect native hosts (parasite spillover); and VI) invasive species may be neither a host nor a parasite, but nevertheless affect native parasite host interactions by interfering with parasite transmission (transmission interference). We discuss the ecological and evolutionary implications of each of these mechanisms and generally note several substantial effects on natural communities and ecosystems via i) mass mortalities of native populations creating strong selection gradients, ii) indirect changes in species interactions within communities and iii) trophic cascading and knock-on effects in food webs that may affect ecosystem function and services. Our review demonstrates a wide range of ecological and evolutionary implications of

  16. Biological warfare: Microorganisms as drivers of host-parasite interactions.

    PubMed

    Dheilly, Nolwenn M; Poulin, Robert; Thomas, Frédéric

    2015-08-01

    Understanding parasite strategies for evasion, manipulation or exploitation of hosts is crucial for many fields, from ecology to medical sciences. Generally, research has focused on either the host response to parasitic infection, or the parasite virulence mechanisms. More recently, integrated studies of host-parasite interactions have allowed significant advances in theoretical and applied biology. However, these studies still provide a simplistic view of these as mere two-player interactions. Host and parasite are associated with a myriad of microorganisms that could benefit from the improved fitness of their partner. Illustrations of such complex multi-player interactions have emerged recently from studies performed in various taxa. In this conceptual article, we propose how these associated microorganisms may participate in the phenotypic alterations induced by parasites and hence in host-parasite interactions, from an ecological and evolutionary perspective. Host- and parasite-associated microorganisms may participate in the host-parasite interaction by interacting directly or indirectly with the other partner. As a result, parasites may develop (i) the disruptive strategy in which the parasite alters the host microbiota to its advantage, and (ii) the biological weapon strategy where the parasite-associated microorganism contributes to or modulates the parasite's virulence. Some phenotypic alterations induced by parasite may also arise from conflicts of interests between the host or parasite and its associated microorganism. For each situation, we review the literature and propose new directions for future research. Specifically, investigating the role of host- and parasite-associated microorganisms in host-parasite interactions at the individual, local and regional level will lead to a holistic understanding of how the co-evolution of the different partners influences how the other ones respond, both ecologically and evolutionary. The conceptual framework we

  17. Bacterial and parasitic diseases of parrots.

    PubMed

    Doneley, Robert J T

    2009-09-01

    As wild-caught birds become increasingly rare in aviculture, there is a corresponding decline in the incidence of bacterial and parasitic problems and an increase in the recognition of the importance of maintaining health through better nutrition and husbandry. Nevertheless, the relatively close confines of captivity mean an increased pathogen load in the environment in which companion and aviary parrots live. This increased pathogen load leads to greater exposure of these birds to bacteria and parasites, and consequently a greater risk of infection and disease. This article discusses bacterial and parasitic infections in companion and aviary parrots. It includes the origins, pathogens, diagnosis, treatment, and some of the associated risk factors. PMID:19732702

  18. Serine protease inhibitors of parasitic helminths.

    PubMed

    Molehin, Adebayo J; Gobert, Geoffrey N; McManus, Donald P

    2012-05-01

    Serine protease inhibitors (serpins) are a superfamily of structurally conserved proteins that inhibit serine proteases and play key physiological roles in numerous biological systems such as blood coagulation, complement activation and inflammation. A number of serpins have now been identified in parasitic helminths with putative involvement in immune regulation and in parasite survival through interference with the host immune response. This review describes the serpins and smapins (small serine protease inhibitors) that have been identified in Ascaris spp., Brugia malayi, Ancylostoma caninum Onchocerca volvulus, Haemonchus contortus, Trichinella spiralis, Trichostrongylus vitrinus, Anisakis simplex, Trichuris suis, Schistosoma spp., Clonorchis sinensis, Paragonimus westermani and Echinococcus spp. and discusses their possible biological functions, including roles in host-parasite interplay and their evolutionary relationships. PMID:22310379

  19. Parasites as probes for prehistoric human migrations?

    PubMed

    Araujo, Adauto; Reinhard, Karl J; Ferreira, Luiz Fernando; Gardner, Scott L

    2008-03-01

    Host-specific parasites of humans are used to track ancient migrations. Based on archaeoparasitology, it is clear that humans entered the New World at least twice in ancient times. The archaeoparasitology of some intestinal parasites in the New World points to migration routes other than the Bering Land Bridge. Helminths have been found in mummies and coprolites in North and South America. Hookworms (Necator and Ancylostoma), whipworms (Trichuris trichiura) and other helminths require specific conditions for life-cycle completion. They could not survive in the cold climate of the northern region of the Americas. Therefore, humans would have lost some intestinal parasites while crossing Beringia. Evidence is provided here from published data of pre-Columbian sites for the peopling of the Americas through trans-oceanic or costal migrations. PMID:18262843

  20. Towards sustainable nematode parasite control of livestock.

    PubMed

    Waller, P J

    1993-06-01

    Farmers worldwide have come to expect, and rely almost exclusively on, broad-spectrum anthelmintics to effectively control nematode parasites amongst their livestock. However, the threats of resistance, residues and ecotoxicity are of increasing concern to the future of chemotherapy. It is imperative that sustainable parasite control schemes be developed and implemented which will integrate a range of techniques to minimise anthelmintic use and still maintain high levels of profitability of the farming enterprise. At present, these need to focus on the better use of existing drugs to maximise their effectiveness and minimise the selection for resistance and impact on the environment. New drugs should also be used according to these principles. In the future it is expected that other non-chemotherapeutic options will become available, e.g. helminth vaccines, resistant hosts, biological control, nematode growth regulators, which will revolutionize the current thinking on nematode parasite control of livestock. PMID:8346643

  1. Companion cropping to manage parasitic plants.

    PubMed

    Pickett, John A; Hamilton, Mary L; Hooper, Antony M; Khan, Zeyaur R; Midega, Charles A O

    2010-01-01

    Parasitic plants, through a range of infestation strategies, can attack crop plants and thereby require management. Because such problems often occur in resource-poor farming systems, companion cropping to manage parasitic plants is an appropriate approach. Many examples of companion cropping for this purpose have been reported, but the use of cattle forage legumes in the genus Desmodium as intercrops has been shown to be particularly successful in controlling the parasitic witchweeds (Striga spp.) that afflict approximately one quarter of sub-Saharan African cereal production. Through the use of this example, the development of effective companion crops is described, together with developments toward widespread adoption and understanding the underlying mechanisms, both for sustainability and ensuring food security, and also for exploitation beyond the cropping systems described here. PMID:20429664

  2. The Pentose Phosphate Pathway in Parasitic Trypanosomatids.

    PubMed

    Kovářová, Julie; Barrett, Michael P

    2016-08-01

    Parasitic trypanosomatids cause important diseases. Dissecting the biochemistry of these organisms offers a means of discovering targets against which inhibitors may be designed and developed as drugs. The pentose phosphate pathway is a key route of glucose metabolism in most organisms, providing NADPH for use as a cellular reductant and various carbohydrate intermediates used in cellular metabolism. The pathway and its enzymes have been studied in Trypanosoma brucei, Trypanosoma cruzi, and various Leishmania species. Its functions in these parasites are becoming clear. Some enzymes of the pathway are essential to the parasites and have structural features distinguishing them from their mammalian counterparts, and this has stimulated several programs of inhibitor discovery with a view to targeting the pathway with new drugs. PMID:27174163

  3. Intestinal parasitism in Malayan aborigines (Orang Asli)*

    PubMed Central

    Dunn, F. L.

    1972-01-01

    Surveys were conducted in the southern Malay peninsula to assess intestinal parasitism in the aboriginal ethnic minority groups. Faecal specimens from 1 273 persons were examined by the thiomersal—iodine—formol direct-smear technique. Prevalences are reported and, for helminth infections, data on worm burdens. The state of sanitation in each of 9 cultural-ecological groups was assessed by means of a simplified system of scoring for variables. Particular attention was paid to relationships between cultural and ecological factors, sanitation, and observed patterns of intestinal parasitism. The author also discusses the fact that the number of parasitic species diminishes in habitats simplified by man, whereas an increase occurs in the prevalence and intensity of the more adaptable species that persist in ecosystems of low complexity. PMID:4537337

  4. Parasitic infection in renal transplant recipients.

    PubMed

    Valar, C; Keitel, E; Dal Prá, R L; Gnatta, D; Santos, A F; Bianco, P D; Sukiennik, T C T; Pegas, K L; Bittar, A E; Oliveira, K T; Garcia, V D

    2007-03-01

    The purpose of this study was to evaluate the prevalence of symptomatic parasitic infections in adult renal transplant recipients. We retrospectively analyzed a sample of 657 adult renal transplant recipients performed from January 2001 to December 2005 for immunosuppression protocol, clinical manifestations, parasite diagnosis, treatments, and outcomes. The prevalence of symptomatic parasitosis infections was 2.4% (16/657). None of the infected patients received cyclosporine in their immunosuppression protocol. Most of the infections were caused by Strongyloids stercoralis (n = 11), followed by Giardia lamblia (n = 3), Toxoplasma gondii (n = 1), and Trypanosoma cruzi: (n = 1). Strongyloides stercoralis was the most frequent agent, causing three cases of hyperinfection including one fatal case. With the new immunosuppressive regimes there must be a suspicion of parasitic infection to avoid the diagnostic delay that can be fatal. Strategies, including empiric treatment for S. stercoralis, must be considered. PMID:17362759

  5. Arthropod larvae misidentified as parasitic worm infection.

    PubMed

    Munisamy, Sreetharan; Kilner, Rachael

    2011-01-01

    A healthy, asymptomatic man living in London, presented with seeing 'worms' in his toilet for two successive summer seasons. Repeated microscopic examination and cultures of both his faeces and urine were normal. He was empirically treated with multiple courses of antihelminthics without resolution of this problem. A sample of the worms was obtained, and positively identified as arthropod larvae under microscopic examination. These larvae do not parasitically colonise humans. It was subsequently deduced that a flying arthropod (most likely Culex pipiens mosquito) had laid eggs in standing toilet water, and the hatched larvae had been mistaken for parasitic worms. The patient was declared free of parasites and remains healthy. This case illustrates the dangers of starting empirical treatment without positive confirmation of causative organisms, which can result in unnecessary and potentially harmful treatment. PMID:22675109

  6. Defining parasite biodiversity at high latitudes of North America: new host and geographic records for Onchocerca cervipedis (Nematoda: Onchocercidae) in moose and caribou

    PubMed Central

    2012-01-01

    Background Onchocerca cervipedis is a filarioid nematode of cervids reported from Central America to boreal regions of North America. It is found primarily in subcutaneous tissues of the legs, and is more commonly known as ‘legworm’. Blackflies are intermediate hosts and transmit larvae to ungulates when they blood-feed. In this article we report the first records of O. cervipedis from high latitudes of North America and its occurrence in previously unrecognized host subspecies including the Yukon-Alaska moose (Alces americanus gigas) and the Grant’s caribou (Rangifer tarandus granti). Methods We examined the subcutaneous connective tissues of the metacarpi and/or metatarsi of 34 moose and one caribou for parasitic lesions. Samples were collected from animals killed by subsistence hunters or animals found dead in the Northwest Territories (NT), Canada and Alaska (AK), USA from 2005 to 2012. Genomic DNA lysate was prepared from nematode fragments collected from two moose. The nd5 region of the mitochondrial DNA was amplified by PCR and sequenced. Results Subcutaneous nodules were found in 12 moose from the NT and AK, and one caribou from AK. Nematodes dissected from the lesions were identified as Onchocerca cervipedis based on morphology of female and male specimens. Histopathological findings in moose included cavitating lesions with multifocal granulomatous cellulitis containing intralesional microfilariae and adults, often necrotic and partially mineralized. Lesions in the caribou included periosteitis with chronic cellulitis, eosinophilic and lymphoplasmacytic infiltrate, and abundant granulation associated with intralesional adult nematodes and larvae. Sequences of the nd5 region (471bp), the first generated for this species, were deposited with Genbank (JN580791 and JN580792). Representative voucher specimens were deposited in the archives of the United States National Parasite Collection. Conclusions The geographic range of O. cervipedis is broader than

  7. Northeast India Helminth Parasite Information Database (NEIHPID): Knowledge Base for Helminth Parasites

    PubMed Central

    Debnath, Manish; Kharumnuid, Graciously; Thongnibah, Welfrank; Tandon, Veena

    2016-01-01

    Most metazoan parasites that invade vertebrate hosts belong to three phyla: Platyhelminthes, Nematoda and Acanthocephala. Many of the parasitic members of these phyla are collectively known as helminths and are causative agents of many debilitating, deforming and lethal diseases of humans and animals. The North-East India Helminth Parasite Information Database (NEIHPID) project aimed to document and characterise the spectrum of helminth parasites in the north-eastern region of India, providing host, geographical distribution, diagnostic characters and image data. The morphology-based taxonomic data are supplemented with information on DNA sequences of nuclear, ribosomal and mitochondrial gene marker regions that aid in parasite identification. In addition, the database contains raw next generation sequencing (NGS) data for 3 foodborne trematode parasites, with more to follow. The database will also provide study material for students interested in parasite biology. Users can search the database at various taxonomic levels (phylum, class, order, superfamily, family, genus, and species), or by host, habitat and geographical location. Specimen collection locations are noted as co-ordinates in a MySQL database and can be viewed on Google maps, using Google Maps JavaScript API v3. The NEIHPID database has been made freely available at http://nepiac.nehu.ac.in/index.php PMID:27285615

  8. Northeast India Helminth Parasite Information Database (NEIHPID): Knowledge Base for Helminth Parasites.

    PubMed

    Biswal, Devendra Kumar; Debnath, Manish; Kharumnuid, Graciously; Thongnibah, Welfrank; Tandon, Veena

    2016-01-01

    Most metazoan parasites that invade vertebrate hosts belong to three phyla: Platyhelminthes, Nematoda and Acanthocephala. Many of the parasitic members of these phyla are collectively known as helminths and are causative agents of many debilitating, deforming and lethal diseases of humans and animals. The North-East India Helminth Parasite Information Database (NEIHPID) project aimed to document and characterise the spectrum of helminth parasites in the north-eastern region of India, providing host, geographical distribution, diagnostic characters and image data. The morphology-based taxonomic data are supplemented with information on DNA sequences of nuclear, ribosomal and mitochondrial gene marker regions that aid in parasite identification. In addition, the database contains raw next generation sequencing (NGS) data for 3 foodborne trematode parasites, with more to follow. The database will also provide study material for students interested in parasite biology. Users can search the database at various taxonomic levels (phylum, class, order, superfamily, family, genus, and species), or by host, habitat and geographical location. Specimen collection locations are noted as co-ordinates in a MySQL database and can be viewed on Google maps, using Google Maps JavaScript API v3. The NEIHPID database has been made freely available at http://nepiac.nehu.ac.in/index.php. PMID:27285615

  9. Cranberry Resistance to Dodder Parasitism: Induced Chemical Defenses and Behavior of a Parasitic Plant.

    PubMed

    Tjiurutue, Muvari Connie; Sandler, Hilary A; Kersch-Becker, Monica F; Theis, Nina; Adler, Lynn A

    2016-02-01

    Parasitic plants are common in many ecosystems, where they can structure community interactions and cause major economic damage. For example, parasitic dodder (Cuscuta spp.) can cause up to 80-100 % yield loss in heavily infested cranberry (Vaccinium macrocarpon) patches. Despite their ecological and economic importance, remarkably little is known about how parasitic plants affect, or are affected by, host chemistry. To examine chemically-mediated interactions between dodder and its cranberry host, we conducted a greenhouse experiment asking whether: (1) dodder performance varies with cranberry cultivar; (2) cultivars differ in levels of phytohormones, volatiles, or phenolics, and whether such variation correlates with dodder parasitism; (3) dodder parasitism induced changes in phytohormones, volatiles, or phenolics, and whether the level of inducible response varied among cultivars. We used five cranberry cultivars to assess host attractiveness to dodder and dodder performance. Dodder performance did not differ across cultivars, but there were marginally significant differences in host attractiveness to dodder, with fewer dodder attaching to Early Black than to any other cultivar. Dodder parasitism induced higher levels of salicylic acid (SA) across cultivars. Cultivars differed in overall levels of flavonols and volatile profiles, but not phenolic acids or proanthocyanidins, and dodder attachment induced changes in several flavonols and volatiles. While cultivars differed slightly in resistance to dodder attachment, we did not find evidence of chemical defenses that mediate these interactions. However, induction of several defenses indicates that parasitism alters traits that could influence subsequent interactions with other species, thus shaping community dynamics. PMID:26905738

  10. Parasitic Infestation and Choice of Reproductive Regimes

    NASA Astrophysics Data System (ADS)

    Sousa, A. O.; de Oliveira, S. Moss; Sá Martins, J. S.

    The Penna model is used to simulate the competition between an asexual parthenogenetic and asexual population inhabiting the same environment represented by a square lattice. With a small probability, a newborn from the sexual population mutates into an asexual one and vice versa. Then, the asexual population rapidly dominates the sexual one, which all but disappears. However, when an infestation by mutating genetically coupled parasites, that mimic trematodes that feed on gonads, is introduced, the outcome may be one in which both populations coevolve or one in which one of the populations overcomes the other, depending on the density of parasites on the lattice.

  11. Parasites may help stabilize cooperative relationships

    PubMed Central

    Little, Ainslie EF; Currie, Cameron R

    2009-01-01

    Background The persistence of cooperative relationships is an evolutionary paradox; selection should favor those individuals that exploit their partners (cheating), resulting in the breakdown of cooperation over evolutionary time. Our current understanding of the evolutionary stability of mutualisms (cooperation between species) is strongly shaped by the view that they are often maintained by partners having mechanisms to avoid or retaliate against exploitation by cheaters. In contrast, we empirically and theoretically examine how additional symbionts, specifically specialized parasites, potentially influence the stability of bipartite mutualistic associations. In our empirical work we focus on the obligate mutualism between fungus-growing ants and the fungi they cultivate for food. This mutualism is exploited by specialized microfungal parasites (genus Escovopsis) that infect the ant's fungal gardens. Using sub-colonies of fungus-growing ants, we investigate the interactions between the fungus garden parasite and cooperative and experimentally-enforced uncooperative ("cheating") pairs of ants and fungi. To further examine if parasites have the potential to help stabilize some mutualisms we conduct Iterative Prisoner's Dilemma (IPD) simulations, a common framework for predicting the outcomes of cooperative/non-cooperative interactions, which incorporate parasitism as an additional factor. Results In our empirical work employing sub-colonies of fungus-growing ants, we found that Escovopsis-infected sub-colonies composed of cheating populations of ants or fungi lost significantly more garden biomass than sub-colonies subjected to infection or cheating (ants or fungi) alone. Since the loss of fungus garden compromises the fitness of both mutualists, our findings suggest that the potential benefit received by the ants or fungi for cheating is outweighed by the increased concomitant cost of parasitism engendered by non-cooperation (cheating). IPD simulations support our

  12. Modelling effect of parasitics in plasmonic FETs

    NASA Astrophysics Data System (ADS)

    Gutin, A.; Ytterdal, T.; Muraviev, Andrey; Shur, M.

    2015-02-01

    The terahertz SPICE FET model has been experimentally validated in Si CMOS and InGaAs HEMTs up to 4.5 THz and updated to account for parasitic gate fringing capacitance and parasitic source and drain resistance. The model is in good agreement with experimental data at low and high THz field intensities. We also show that introducing additional capacitances linking the drain and gate electrodes may lead to enhancement of the THz plasmonic detector response at lower THz frequencies. The simulation results of the plasmonic detector response to a single terahertz pulse are in good agreement with our measured data.

  13. Biodiversity loss decreases parasite diversity: theory and patterns

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2012-01-01

    Past models have suggested host–parasite coextinction could lead to linear, or concave down relationships between free-living species richness and parasite richness. I explored several models for the relationship between parasite richness and biodiversity loss. Life cycle complexity, low generality of parasites and sensitivity of hosts reduced the robustness of parasite species to the loss of free-living species diversity. Food-web complexity and the ordering of extinctions altered these relationships in unpredictable ways. Each disassembly of a food web resulted in a unique relationship between parasite richness and the richness of free-living species, because the extinction trajectory of parasites was sensitive to the order of extinctions of free-living species. However, the average of many disassemblies tended to approximate an analytical model. Parasites of specialist hosts and hosts higher on food chains were more likely to go extinct in food-web models. Furthermore, correlated extinctions between hosts and parasites (e.g. if parasites share a host with a specialist predator) led to steeper declines in parasite richness with biodiversity loss. In empirical food webs with random removals of free-living species, the relationship between free-living species richness and parasite richness was, on average, quasi-linear, suggesting biodiversity loss reduces parasite diversity more than previously thought.

  14. Active migration and passive transport of malaria parasites.

    PubMed

    Douglas, Ross G; Amino, Rogerio; Sinnis, Photini; Frischknecht, Freddy

    2015-08-01

    Malaria parasites undergo a complex life cycle between their hosts and vectors. During this cycle the parasites invade different types of cells, migrate across barriers, and transfer from one host to another. Recent literature hints at a misunderstanding of the difference between active, parasite-driven migration and passive, circulation-driven movement of the parasite or parasite-infected cells in the various bodily fluids of mosquito and mammalian hosts. Because both active migration and passive transport could be targeted in different ways to interfere with the parasite, a distinction between the two ways the parasite uses to get from one location to another is essential. We discuss the two types of motion needed for parasite dissemination and elaborate on how they could be targeted by future vaccines or drugs. PMID:26001482

  15. Does moving up a food chain increase aggregation in parasites?

    PubMed

    Lester, R J G; McVinish, R

    2016-05-01

    General laws in ecological parasitology are scarce. Here, we evaluate data on numbers of fish parasites published by over 200 authors to determine whether acquiring parasites via prey is associated with an increase in parasite aggregation. Parasite species were grouped taxonomically to produce 20 or more data points per group as far as possible. Most parasites that remained at one trophic level were less aggregated than those that had passed up a food chain. We use a stochastic model to show that high parasite aggregation in predators can be solely the result of the accumulation of parasites in their prey. The model is further developed to show that a change in the predators feeding behaviour with age may further increase parasite aggregation. PMID:27170651

  16. Parasitism as a Driver of Trophic Niche Specialisation.

    PubMed

    Britton, J Robert; Andreou, Demetra

    2016-06-01

    The population trophic niche of free-living species can be subdivided into smaller niches comprising individuals specialising on specific food items. The roles of parasites in creating these specialised subgroups remain unclear. Intrapopulation differences in parasite infections can develop from specialist individuals within populations. Their differences in morphology and habitat can increase their exposure to intermediate hosts via infected prey, altering their parasite fauna. However, we also suggest that parasite infections can drive this niche specialisation. Through mechanisms including parasite manipulation, altered host phenotypes, and/ or parasite-mediated competition, parasites can alter the resource availability of their hosts, altering their trophic niches. Thus, trophic niche specialisations could result from parasitism via varying influences on host traits, raising questions for future research. PMID:26968643

  17. Imaging liver-stage malaria parasites.

    PubMed

    Rankin, Kathleen E; Graewe, Stefanie; Heussler, Volker T; Stanway, Rebecca R

    2010-05-01

    Plasmodium parasites, the causative agents of malaria, first invade and develop within hepatocytes before infecting red blood cells and causing symptomatic disease. Because of the low infection rates in vitro and in vivo, the liver stage of Plasmodium infection is not very amenable to biochemical assays, but the large size of the parasite at this stage in comparison with Plasmodium blood stages makes it accessible to microscopic analysis. A variety of imaging techniques has been used to this aim, ranging from electron microscopy to widefield epifluorescence and laser scanning confocal microscopy. High-speed live video microscopy of fluorescent parasites in particular has radically changed our view on key events in Plasmodium liver-stage development. This includes the fate of motile sporozoites inoculated by Anopheles mosquitoes as well as the transport of merozoites within merosomes from the liver tissue into the blood vessel. It is safe to predict that in the near future the application of the latest microscopy techniques in Plasmodium research will bring important insights and allow us spectacular views of parasites during their development in the liver. PMID:20180802

  18. Infection with parasitic nematodes confounds vaccination efficacy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The production of IL-12 and IFN-' resulting from exposure to many bacterial, viral, and protozoan pathogens is responsible for Th1-derived protective responses that also can inhibit development of Th2-cells expressing IL-4-dependent immunity to extra cellular helminth parasites and vice versa. In a ...

  19. Quantifying Transmission Investment in Malaria Parasites

    PubMed Central

    Greischar, Megan A.; Mideo, Nicole; Read, Andrew F.; Bjørnstad, Ottar N.

    2016-01-01

    Many microparasites infect new hosts with specialized life stages, requiring a subset of the parasite population to forgo proliferation and develop into transmission forms. Transmission stage production influences infectivity, host exploitation, and the impact of medical interventions like drug treatment. Predicting how parasites will respond to public health efforts on both epidemiological and evolutionary timescales requires understanding transmission strategies. These strategies can rarely be observed directly and must typically be inferred from infection dynamics. Using malaria as a case study, we test previously described methods for inferring transmission stage investment against simulated data generated with a model of within-host infection dynamics, where the true transmission investment is known. We show that existing methods are inadequate and potentially very misleading. The key difficulty lies in separating transmission stages produced by different generations of parasites. We develop a new approach that performs much better on simulated data. Applying this approach to real data from mice infected with a single Plasmodium chabaudi strain, we estimate that transmission investment varies from zero to 20%, with evidence for variable investment over time in some hosts, but not others. These patterns suggest that, even in experimental infections where host genetics and other environmental factors are controlled, parasites may exhibit remarkably different patterns of transmission investment. PMID:26890485

  20. Impacts of globalization on foodborne parasites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2010 an estimated 3% of the world’s population lived outside their country of origin. Among immigrants, tourists, and business travellers worldwide several foodborne parasites are frequently found including Ascaris, Trichiuris, hookworms, Enterobius, Fasciola, Hymenolepis, and several protozoa. T...

  1. Parasite Stress Predicts Offspring Sex Ratio

    PubMed Central

    Dama, Madhukar Shivajirao

    2012-01-01

    In this study, I predict that the global variation of offspring sex ratio might be influenced in part by the level of parasite stress. From an energetic standpoint, higher gestational costs of producing a male offspring could decrease male births in a population with limited resources. This implies that, any factor that limits the parental resources could be expected to favor female offspring production. Human sex ratio at birth (SRB) is believed to be influenced by numerous socioeconomic, biological, and environmental factors. Here, I test a prediction that parasite stress, by virtue of its effects on the general health condition, may limit the parental investment ability and therefore could influence the SRB at the population level. The statistical analysis supports this prediction, and show that the level of parasite stress has a significant inverse relation with population SRB across the world. Further, this relation is many-folds stronger than the association of SRB with other factors, like; polygyny, fertility, latitude, and son-preference. Hence, I propose that condition affecting ability of parasites (but not adaptive significance) could be a likely causal basis for the striking variation of SRB across populations. PMID:23049967

  2. Blood parasites in North American waterfowl

    USGS Publications Warehouse

    Herman, C.M.

    1968-01-01

    One thing seems to stand out in the overall knowledge we have of the blood parasites of waterfowl, as previously noted by Herman and Wehr, (1954): the greatest potential of losses is in the younger age groups, usually those birds 5-10 weeks old. In Leucocytozoon infections, death occurs as early as the first or second week of the bird's life. As a conclusion to this presentation, I wish to emphasize that there are many gaps in our knowledge of these parasites and that the answers are to be obtained by further studies in the young birds. Data obtained from studies of birds shot by hunters or from specimens taken during fall or winter banding operations can be expected to be far less rewarding and significanf than studies of goslings and ducklings. We need much more knowledge of these parasites and their vectors and other relationships before we can develop management procedures to combat or contain them. It will require many more studies in depth to achieve this goal, but the facts are there waiting to be uncovered. These parasites will have to be regulated along with breeding habitat, hunter take, and other factors that all add up to maintenance and management of waterfowl.

  3. Helminth parasites of Australasian monotremes and marsupials.

    PubMed

    Spratt, David M; Beveridge, Ian

    2016-01-01

    This work includes all published records, to April 2015, of the helminths occurring in Australasian monotremes and marsupials, with due regard for synonymy and an attempt to include life history studies, pathological observations and epidemiology. It also contains all unpublished records known to us and referrable, by accession numbers, to curated collections in Australia and overseas. Information is presented by host family, genus, species, sub-species or chromosome race and includes the names of all host species from which no parasites have been recorded. Most records pertain to free-living and wild animals; where they do not, they have been annotated appropriately. Unpublished information known to the authors has been included in annotations to entries, where appropriate. Parasites are arranged as follows: Trematoda, Cestoda, Nematoda, Acanthocephala, and their systematic position is indicated by abbreviations placed before the name. The authority for each parasite record is given after the author's name, as a number in parentheses, and this refers to the numbered (1-664) list of references.        A parasite-host list is presented alphabetically, irrespective of taxonomic affiliation together with the host species in which they are known to occur. Hosts are arranged initially by family and alphabetically within each family. PMID:27395568

  4. Dealing with Parasites in Group Projects.

    ERIC Educational Resources Information Center

    Carter, Judy H.

    While it is generally accepted that people working in groups can accomplish more than people working individually, it is equally accepted that parasites will attempt to feed on the other group members. Group work has been called by several names--group learning, cooperative learning, collaborative learning--all of which carry slightly different…

  5. Cases of parasitic pneumonia in Scottish cattle.

    PubMed

    2016-02-01

    Parasitic pneumonia in cattleNutritional osteodystrophy in cattleWhite liver disease in lambsErysipelas in pigsLead poisoning and atherosclerosis in an eagle These are among matters discussed in the disease surveillance report for October 2015 from SAC Consulting: Veterinary Services (SAC C VS). PMID:26851101

  6. Indirect effects of parasites in invasions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduced species disrupt native communities and biodiversity worldwide. Parasitic infections (and at times, their absence) are thought to be a key component in the success and impact of biological invasions by plants and animals. They can facilitate or limit invasions, and positively or negatively...

  7. Microstrip antenna array with parasitic elements

    NASA Technical Reports Server (NTRS)

    Lee, Kai F.; Acosta, Roberto J.; Lee, Richard Q.

    1987-01-01

    Discussed is the design of a large microstrip antenna array in terms of subarrays consisting of one fed patch and several parasitic patches. The potential advantages of this design are discussed. Theoretical radiation patterns of a subarray in the configuration of a cross are presented.

  8. Parasitism enhances tilapia susceptibility to Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare, a Gram-negative bacterium, is the causative agent of columnaris disease. Many commercially important freshwater fish worldwide are susceptible to columnaris disease that can result in high fish mortality. Ichthyophthirius multifiliis (Ich) is a protozoan parasite in many ...

  9. [Parasitic diseases of the central nervous system].

    PubMed

    Schmutzhard, E

    2010-02-01

    Central nervous system infections and infestations by protozoa and helminths constitute a problem of increasing importance throughout all of central European and northern/western countries. This is partially due to the globalisation of our society, tourists and business people being more frequently exposed to parasitic infection/infestation in tropical countries than in moderate climate countries. On top of that, migrants may import chronic infestations and infections with parasitic pathogens, eventually also--sometimes exclusively--involving the nervous system. Knowledge of epidemiology, initial clinical signs and symptoms, diagnostic procedures as well as specific chemotherapeutic therapies and adjunctive therapeutic strategies is of utmost important in all of these infections and infestations of the nervous systems, be it by protozoa or helminths. This review lists, mainly in the form of tables, all possible infections and infestations of the nervous systems by protozoa and by helminths. Besides differentiating parasitic diseases of the nervous system seen in migrants, tourists etc., it is very important to have in mind that disease-related (e.g. HIV) or iatrogenic immunosuppression has led to the increased occurrence of a wide variety of parasitic infections and infestations of the nervous system (e. g. babesiosis, Chagas disease, Strongyloides stercoralis infestation, toxoplasmosis, etc.). PMID:20111855

  10. Immunodiagnosis of parasitic diseases with synthetic peptides.

    PubMed

    Noya, O; Patarroyo, M E; Guzmán, F; Alarcón de Noya, B

    2003-08-01

    Parasitic diseases remain as a major public health problem worldwide, not only based on their historically high morbidity and mortality rates, but also because risk factors associated with their transmission are increasing. Laboratory diagnosis and particularly immunodiagnosis is a basic tool for the demonstration, clinical management and control of these infections. Classically, the serological tests for the detection of antibodies or antigens are based on the use of crude and purified antigens. Synthetic peptides have opened a new field and perspectives, as the source of pure epitopes and molecules for diagnosis of malaria, Chagas' disease, leishmaniasis, schistosomiasis, hidatidosis, cysticercosis and fasciolosis based on the detection of antibodies and circulating antigens. Herein, are critically reviewed the relevant advances and applications of the synthetic peptides on immunodiagnosis of parasitic diseases. A variety of sequences, constructs (monomers, polymers, MAPs), immunological methods and samples have been used, demonstrating their diagnostic potential. However, in most parasitic infections it is necessary to use more than a single peptide in order to avoid the genetic restriction against certain epitopes, as well as to test them in well characteized groups of patients, in order to confirm their sensitivity and specificity. The concept of multidiagnosis with synthetic peptides, using a novel multi-dot blot assay is introduced. Finally, the chemical imitation of antigens, offers a tremendous posibilities in the diagnosis of parasitic infections in developing countries since this strategy is cheaper, simpler, reproducible, useful for large scale testing and in most cases, specific and sensitive. PMID:14529537

  11. SURVIVAL OF PARASITE EGGS IN STORED SLUDGE

    EPA Science Inventory

    The inactivation rates of digester-resistant parasite eggs in laboratory-stored sludge were measured to determine their potential fate in sludge lagoons. Eggs from roundworms (Ascaris, Toxocara and Trichuris) and a tapeworm (Hymenolepis) were added to domestic sludges either befo...

  12. Quantifying Transmission Investment in Malaria Parasites.

    PubMed

    Greischar, Megan A; Mideo, Nicole; Read, Andrew F; Bjørnstad, Ottar N

    2016-02-01

    Many microparasites infect new hosts with specialized life stages, requiring a subset of the parasite population to forgo proliferation and develop into transmission forms. Transmission stage production influences infectivity, host exploitation, and the impact of medical interventions like drug treatment. Predicting how parasites will respond to public health efforts on both epidemiological and evolutionary timescales requires understanding transmission strategies. These strategies can rarely be observed directly and must typically be inferred from infection dynamics. Using malaria as a case study, we test previously described methods for inferring transmission stage investment against simulated data generated with a model of within-host infection dynamics, where the true transmission investment is known. We show that existing methods are inadequate and potentially very misleading. The key difficulty lies in separating transmission stages produced by different generations of parasites. We develop a new approach that performs much better on simulated data. Applying this approach to real data from mice infected with a single Plasmodium chabaudi strain, we estimate that transmission investment varies from zero to 20%, with evidence for variable investment over time in some hosts, but not others. These patterns suggest that, even in experimental infections where host genetics and other environmental factors are controlled, parasites may exhibit remarkably different patterns of transmission investment. PMID:26890485

  13. ZOONOTIC PARASITES, OUR ENVIROMENT AND CHANGE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Environmental changes arising from nature and human activity are affecting patterns for the occurrence and significance of many infectious diseases, including zoonotic parasites, which are those naturally transmitted between domestic animals or wildlife and people. As these changes continue, and pe...

  14. Oxidative Stress Control by Apicomplexan Parasites

    PubMed Central

    Izui, Natália M.; Schettert, Isolmar; Liebau, Eva

    2015-01-01

    Apicomplexan parasites cause infectious diseases that are either a severe public health problem or an economic burden. In this paper we will shed light on how oxidative stress can influence the host-pathogen relationship by focusing on three major diseases: babesiosis, coccidiosis, and toxoplasmosis. PMID:25722976

  15. Economics of gastrointestinal parasitism of cattle.

    PubMed

    Corwin, R M

    1997-11-01

    Understandably, cattle are raised for profit, as beef and/or dairy. Anything that negates that equation results in a loss to the producer and to the livestock economy. Thus, parasites negatively affect the economy of the industry. Worldwide, gastrointestinal nematode parasites, especially Ostertagia ostertagi, and those of the respiratory tract (Dictyocaulus viviparus) have a potentially major impact on herd health. In the past 10-15 years, anthelmintic (AH) drug development and the strategic use of AH have positively balanced the economic equation, so that overall, parasitism in cattle is often observed or determined to be subclinical or economical. Other control measures, such as better pasture management, are also being developed to enhance herd health and the cattle economy. The determination of the economic impact of parasitism has thus become less apparent, to the extent that measures, such as performance parameters, must be used to measure differences between treated and untreated animals or herds. These include weight gain, reproduction, lactation and forage use. To determine the effectiveness of control measures, field trials are designed to measure these parameters by the demonstration of improved performance. Because these trials are conducted in a competitive mode, results are often debated by competitors and by the scientific community because of study design. Variables must then be taken into consideration in the interpretation of results. It is now well known that, with the generation of new AH and appropriately-timed administration, parasitism of well-managed herds has been reduced to subclinical levels. Thus, we are now in the process of fine-tuning the positive effect of these control measures for enhanced production. Understandably, beef and dairy producers have 'production of high quality commodities' at a cost-effective level as a common goal. Successful cattlemen calculate expenditures and income by line item including veterinary expenses and

  16. Host life history and host-parasite syntopy predict behavioural resistance and tolerance of parasites.

    PubMed

    Sears, Brittany F; Snyder, Paul W; Rohr, Jason R

    2015-05-01

    There is growing interest in the role that life-history traits of hosts, such as their 'pace-of-life', play in the evolution of resistance and tolerance to parasites. Theory suggests that, relative to host species that have high syntopy (local spatial and temporal overlap) with parasites, host species with low syntopy should have lower selection pressures for more constitutive (always present) and costly defences, such as tolerance, and greater reliance on more inducible and cheaper defences, such as behaviour. Consequently, we postulated that the degree of host-parasite syntopy, which is negatively correlated with host pace-of-life (an axis reflecting the developmental rate of tadpoles and the inverse of their size at metamorphosis) in our tadpole-parasitic cercarial (trematode) system, would be a negative and positive predictor of behavioural resistance and tolerance, respectively. To test these hypotheses, we exposed seven tadpole species to a range of parasite (cercarial) doses crossed with anaesthesia treatments that controlled for anti-parasite behaviour. We quantified host behaviour, successful and unsuccessful infections, and each species' reaction norm for behavioural resistance and tolerance, defined as the slope between cercarial exposure (or attempted infections) and anti-cercarial behaviours and mass change, respectively. Hence, tolerance is capturing any cost of parasite exposure. As hypothesized, tadpole pace-of-life was a significant positive predictor of behavioural resistance and negative predictor of tolerance, a result that is consistent with a trade-off between behavioural resistance and tolerance across species that warrants further investigation. Moreover, these results were robust to considerations of phylogeny, all possible re-orderings of the three fastest or slowest paced species, and various measurements of tolerance. These results suggest that host pace-of-life and host-parasite syntopy are powerful drivers of both the strength and type

  17. Trichinella inflammatory myopathy: host or parasite strategy?

    PubMed Central

    2011-01-01

    The parasitic nematode Trichinella has a special relation with muscle, because of its unique intracellular localization in the skeletal muscle cell, completely devoted in morphology and biochemistry to become the parasite protective niche, otherwise called the nurse cell. The long-lasting muscle infection of Trichinella exhibits a strong interplay with the host immune response, mainly characterized by a Th2 phenotype. The aim of this review is to illustrate the role of the Th2 host immune response at the muscle level during trichinellosis in different experimental models, such as knock-out or immuno-modulated mice. In particular, in knock-out mice a crucial role of IL-10 is evident for the regulation of inflammation intensity. The muscular host immune response to Trichinella is partially regulated by the intestinal phase of the parasite which emphasizes the intensity of the following muscle inflammation compared with animals infected by synchronized injections of newborn larvae. In eosinophil-ablated mice such as PHIL and GATA-- animals it was observed that there was an increased NOS2 expression in macrophages, driven by higher IFN-γ release, thus responsible for muscle larva damage. Besides modulation of the intestinal stage of the infection, using recombinant IL-12, increases the muscular parasite burden delaying adult worm expulsion from the intestine. Furthermore, a Th1 adjuvant of bacterial origin called Helicobacter pylori neutrophil activating protein (HP-NAP), administered during the intestinal phase of trichinellosis, alters the Th2 dependent response at muscle level. All these data from the literature delineate then a mutual adaptation between parasite and host immune response in order to achieve a strategic compromise between two evolutionary forces pointed towards the survival of both species. PMID:21429196

  18. Role of nitric oxide in parasitic infections.

    PubMed Central

    James, S L

    1995-01-01

    Nitric oxide is produced by a number of different cell types in response to cytokine stimulation and thus has been found to play a role in immunologically mediated protection against a growing list of protozoan and helminth parasites in vitro and in animal models. The biochemical basis of its effects on the parasite targets appears to involve primarily inactivation of enzymes crucial to energy metabolism and growth, although it has other biologic activities as well. NO is produced not only by macrophages and macrophage-like cells commonly associated with the effector arm of cell-mediated immune reactivity but also by cells commonly considered to lie outside the immunologic network, such as hepatocytes and endothelial cells, which are intimately involved in the life cycle of a number of parasites. NO production is stimulated by gamma interferon in combination with tumor necrosis factor alpha or other secondary activation signals and is regulated by a number of cytokines (especially interleukin-4, interleukin-10, and transforming growth factor beta) and other mediators, as well as through its own inherent inhibitory activity. The potential for design of prevention and/or intervention approaches against parasitic infection (e.g., vaccination or combination chemo- and immunotherapy strategies) on the basis of induction of cell-mediated immunity and NO production appears to be great, but the possible pathogenic consequences of overproduction of NO must be taken into account. Moreover, more research on the role and regulation of NO in human parasitic infection is needed before its possible clinical relevance can be determined. PMID:8531884

  19. For Host's Sake: The Pluses of Parasite Preservation.

    PubMed

    Spencer, Hamish G; Zuk, Marlene

    2016-05-01

    Conservation biologists now realize that parasites of endangered hosts should be conserved for their own sake and as part of their host's natural environment. But parasites should also be conserved because parasitic exposure might be crucial to the host's development of a fully functional immune system and hence to the survival of the host. PMID:27020732

  20. Alternative prey use affects helminth parasite infections in grey wolves.

    PubMed

    Friesen, Olwyn C; Roth, James D

    2016-09-01

    Predators affect prey populations not only through direct predation, but also by acting as definitive hosts for their parasites and completing parasite life cycles. Understanding the affects of parasitism on prey population dynamics requires knowing how their predators' parasite community is affected by diet and prey availability. Ungulates, such as moose (Alces americanus) and white-tailed deer (Odocoileus virginianus), are often important prey for wolves (Canis lupus), but wolves also consume a variety of alternative prey, including beaver (Castor canadensis) and snowshoe hare (Lepus americanus). The use of alternative prey, which may host different or fewer parasites than ungulates, could potentially reduce overall abundance of ungulate parasites within the ecosystem, benefiting both wolves and ungulate hosts. We examined parasites in wolf carcasses from eastern Manitoba and estimated wolf diet using stable isotope analysis. Taeniidae cestodes were present in most wolves (75%), reflecting a diet primarily comprised of ungulates, but nematodes were unexpectedly rare. Cestode abundance was negatively related to the wolf's δ(13) C value, indicating diet affects parasite abundance. Wolves that consumed a higher proportion of beaver and caribou (Rangifer tarandus), estimated using Bayesian mixing models, had lower cestode abundance, suggesting the use of these alternative prey can reduce parasite loads. Long-term consumption of beavers may lower the abundance of adult parasites in wolves, eventually lowering parasite density in the region and ultimately benefiting ungulates that serve as intermediate hosts. Thus, alternative prey can affect both predator-prey and host-parasite interactions and potentially affect food web dynamics. PMID:27155132

  1. The contagion indicator hypothesis for parasite-mediated sexual selection.

    PubMed

    Able, D J

    1996-03-01

    Hamilton and Zuk [Hamilton, W. D. & Zuk, M. (1982) Science 218, 384-387] proposed that females choosing mates based on the degree of expression of male characters obtain heritable parasite resistance for their offspring. Alternatively, the "contagion indicator" hypothesis posits that females choose mates based on the degree of expression of male characters because the latter indicate a male's degree of infestation of parasites and thus the risk that choosing females and their offspring will acquire these parasites. I examined whether parasite transmittability affects the probability that parasite intensity and male mating success are negatively correlated in intraspecific studies of parasite-mediated sexual selection. When females risk infection of themselves or their future offspring as a result of mating with a parasitized male, negative relationships between parasite intensity and male mating success are significantly more likely to occur than when females do not risk such infection. The direct benefit to females of avoiding parasitic infection is proposed to lead to the linkage between variable secondary sexual characters and the intensity of transmittable parasites. The direct benefits of avoiding associatively transmittable parasites should be considered in future studies of parasite-mediated sexual selection. PMID:8700912

  2. Parasitic infestation of lung: An unusual cause of interstitial pneumonitis

    PubMed Central

    Shah, Parth; Kate, Arvind H; Nester, Nora; Patole, Kamlakar; Leuppi, Joerg D; Chhajed, Prashant N

    2016-01-01

    Parasite infections are increasing worldwide due to increasing migration and traveling. Parasitic infections can affect lungs and present as a focal or diffuse lung diseases. High index of suspicion and detailed history are most important. We present a case of interstitial pneumonitis caused by parasite infestation, which was diagnosed on transbronchial lung biopsy. PMID:27051117

  3. Egg size matching by an intraspecific brood parasite

    USGS Publications Warehouse

    Lemons, Patrick R.; Sedinger, James S.

    2011-01-01

    Avian brood parasitism provides an ideal system with which to understand animal recognition and its affect on fitness. This phenomenon of laying eggs in the nests of other individuals has classically been framed from the perspective of interspecific brood parasitism and host recognition of parasitic eggs. Few examples exist of strategies adopted by intraspecific brood parasites to maximize success of parasitic eggs. Intraspecific brood parasitism within precocial birds can be a risky strategy in that hatch synchrony is essential to reproductive success. Given that egg size is positively correlated with incubation time, parasitic birds would benefit by recognizing and selecting hosts with a similar egg size. Intraspecific brood parasitism is an alternative reproductive strategy in black brant (Branta bernicla nigricans), a colonial nesting goose with precocial young. Based on a randomization test, parasitic eggs in this study differed less in size from eggs in their host's nests than did random eggs placed in random nests. Parasitic eggs were remarkably similar in size to hosts’ eggs, differing by <2% of volume on average from host eggs, whereas randomly paired eggs in random nests differed by nearly 8%. The precision with which parasitic brant match the egg size of hosts in our study supports our hypothesis that brant match egg size of hosts, thereby maximizing hatching success of their parasitic eggs.

  4. Richness and distribution of tropical oyster parasites in two oceans.

    PubMed

    Pagenkopp Lohan, Katrina M; Hill-Spanik, Kristina M; Torchin, Mark E; Aguirre-Macedo, Leopoldina; Fleischer, Robert C; Ruiz, Gregory M

    2016-08-01

    Parasites can exert strong effects on population to ecosystem level processes, but data on parasites are limited for many global regions, especially tropical marine systems. Characterizing parasite diversity and distributions are the first steps towards understanding the potential impacts of parasites. The Panama Canal serves as an interesting location to examine tropical parasite diversity and distribution, as it is a conduit between two oceans and a hub for international trade. We examined metazoan and protistan parasites associated with ten oyster species collected from both Panamanian coasts, including the Panama Canal and Bocas del Toro. We found multiple metazoan taxa (pea crabs, Stylochus spp., Urastoma cyrinae). Our molecular screening for protistan parasites detected four species of Perkinsus (Perkinsus marinus, Perkinsus chesapeaki, Perkinsus olseni, Perkinsus beihaiensis) and several haplosporidians, including two genera (Minchinia, Haplosporidium). Species richness was higher for the protistan parasites than for the metazoans, with haplosporidian richness being higher than Perkinsus richness. Perkinsus species were the most frequently detected and most geographically widespread among parasite groups. Parasite richness and overlap differed between regions, locations and oyster hosts. These results have important implications for tropical parasite richness and the dispersal of parasites due to shipping associated with the Panama Canal. PMID:27263626

  5. The machinery underlying malaria parasite virulence is conserved between rodent and human malaria parasites

    PubMed Central

    De Niz, Mariana; Ullrich, Ann-Katrin; Heiber, Arlett; Blancke Soares, Alexandra; Pick, Christian; Lyck, Ruth; Keller, Derya; Kaiser, Gesine; Prado, Monica; Flemming, Sven; del Portillo, Hernando; Janse, Chris J.; Heussler, Volker; Spielmann, Tobias

    2016-01-01

    Sequestration of red blood cells infected with the human malaria parasite Plasmodium falciparum in organs such as the brain is considered important for pathogenicity. A similar phenomenon has been observed in mouse models of malaria, using the rodent parasite Plasmodium berghei, but it is unclear whether the P. falciparum proteins known to be involved in this process are conserved in the rodent parasite. Here we identify the P. berghei orthologues of two such key factors of P. falciparum, SBP1 and MAHRP1. Red blood cells infected with P. berghei parasites lacking SBP1 or MAHRP1a fail to bind the endothelial receptor CD36 and show reduced sequestration and virulence in mice. Complementation of the mutant P. berghei parasites with the respective P. falciparum SBP1 and MAHRP1 orthologues restores sequestration and virulence. These findings reveal evolutionary conservation of the machinery underlying sequestration of divergent malaria parasites and support the notion that the P. berghei rodent model is an adequate tool for research on malaria virulence. PMID:27225796

  6. Discrimination of fish populations using parasites: Random Forests on a 'predictable' host-parasite system.

    PubMed

    Pérez-Del-Olmo, A; Montero, F E; Fernández, M; Barrett, J; Raga, J A; Kostadinova, A

    2010-10-01

    We address the effect of spatial scale and temporal variation on model generality when forming predictive models for fish assignment using a new data mining approach, Random Forests (RF), to variable biological markers (parasite community data). Models were implemented for a fish host-parasite system sampled along the Mediterranean and Atlantic coasts of Spain and were validated using independent datasets. We considered 2 basic classification problems in evaluating the importance of variations in parasite infracommunities for assignment of individual fish to their populations of origin: multiclass (2-5 population models, using 2 seasonal replicates from each of the populations) and 2-class task (using 4 seasonal replicates from 1 Atlantic and 1 Mediterranean population each). The main results are that (i) RF are well suited for multiclass population assignment using parasite communities in non-migratory fish; (ii) RF provide an efficient means for model cross-validation on the baseline data and this allows sample size limitations in parasite tag studies to be tackled effectively; (iii) the performance of RF is dependent on the complexity and spatial extent/configuration of the problem; and (iv) the development of predictive models is strongly influenced by seasonal change and this stresses the importance of both temporal replication and model validation in parasite tagging studies. PMID:20602856

  7. The machinery underlying malaria parasite virulence is conserved between rodent and human malaria parasites.

    PubMed

    De Niz, Mariana; Ullrich, Ann-Katrin; Heiber, Arlett; Blancke Soares, Alexandra; Pick, Christian; Lyck, Ruth; Keller, Derya; Kaiser, Gesine; Prado, Monica; Flemming, Sven; Del Portillo, Hernando; Janse, Chris J; Heussler, Volker; Spielmann, Tobias

    2016-01-01

    Sequestration of red blood cells infected with the human malaria parasite Plasmodium falciparum in organs such as the brain is considered important for pathogenicity. A similar phenomenon has been observed in mouse models of malaria, using the rodent parasite Plasmodium berghei, but it is unclear whether the P. falciparum proteins known to be involved in this process are conserved in the rodent parasite. Here we identify the P. berghei orthologues of two such key factors of P. falciparum, SBP1 and MAHRP1. Red blood cells infected with P. berghei parasites lacking SBP1 or MAHRP1a fail to bind the endothelial receptor CD36 and show reduced sequestration and virulence in mice. Complementation of the mutant P. berghei parasites with the respective P. falciparum SBP1 and MAHRP1 orthologues restores sequestration and virulence. These findings reveal evolutionary conservation of the machinery underlying sequestration of divergent malaria parasites and support the notion that the P. berghei rodent model is an adequate tool for research on malaria virulence. PMID:27225796

  8. Expanding the antimalarial toolkit: Targeting host–parasite interactions

    PubMed Central

    Duffy, Patrick E.

    2016-01-01

    Recent successes in malaria control are threatened by drug-resistant Plasmodium parasites and insecticide-resistant Anopheles mosquitoes, and first generation vaccines offer only partial protection. New research approaches have highlighted host as well as parasite molecules or pathways that could be targeted for interventions. In this study, we discuss host–parasite interactions at the different stages of the Plasmodium life cycle within the mammalian host and the potential for therapeutics that prevent parasite migration, invasion, intracellular growth, or egress from host cells, as well as parasite-induced pathology. PMID:26834158

  9. The study of parasite sharing for surveillance of zoonotic diseases

    NASA Astrophysics Data System (ADS)

    Farrell, Maxwell J.; Berrang-Ford, Lea; Davies, T. Jonathan

    2013-03-01

    Determining the factors that influence the transmission of parasites among hosts is important for directing surveillance of animal parasites before they successfully emerge in humans, and increasing the efficacy of programs for the control and management of zoonotic diseases. Here we present a review of recent advances in the study of parasite sharing, wildlife ecology, and epidemiology that could be extended and incorporated into proactive surveillance frameworks for multi-host infectious diseases. These methods reflect emerging interdisciplinary techniques with significant promise for the identification of future zoonotic parasites and unknown reservoirs of current zoonoses, strategies for the reduction of parasite prevalence and transmission among hosts, and decreasing the burden of infectious diseases.

  10. Expanding the antimalarial toolkit: Targeting host-parasite interactions.

    PubMed

    Langhorne, Jean; Duffy, Patrick E

    2016-02-01

    Recent successes in malaria control are threatened by drug-resistant Plasmodium parasites and insecticide-resistant Anopheles mosquitoes, and first generation vaccines offer only partial protection. New research approaches have highlighted host as well as parasite molecules or pathways that could be targeted for interventions. In this study, we discuss host-parasite interactions at the different stages of the Plasmodium life cycle within the mammalian host and the potential for therapeutics that prevent parasite migration, invasion, intracellular growth, or egress from host cells, as well as parasite-induced pathology. PMID:26834158

  11. Parasite Removal, but Not Herbivory, Deters Future Parasite Attachment on Tomato

    PubMed Central

    Tjiurutue, Muvari Connie; Palmer-Young, Evan C.; Adler, Lynn S.

    2016-01-01

    Plants face many antagonistic interactions that occur sequentially. Often, plants employ defense strategies in response to the initial damage that are highly specific and can affect interactions with subsequent antagonists. In addition to herbivores and pathogens, plants face attacks by parasitic plants, but we know little about how prior herbivory compared to prior parasite attachment affects subsequent host interactions. If host plants can respond adaptively to these different damage types, we predict that prior parasitism would have a greater deterrent effect on subsequent parasites than would prior herbivory. To test the effects of prior parasitism and prior herbivory on subsequent parasitic dodder (Cuscuta spp.) preference, we conducted two separate greenhouse studies with tomato hosts (Solanum lycopersicum). In the first experiment, we tested the effects of previous dodder attachment on subsequent dodder preference on tomato hosts using three treatments: control plants that had no previous dodder attachment; dodder-removed plants that had an initial dodder seedling attached, removed and left in the same pot to simulate parasite death; and dodder-continuous plants with an initial dodder seedling that remained attached. In the second experiment, we tested the effects of previous caterpillar damage (Spodoptera exigua) and mechanical damage on future dodder attachment on tomato hosts. Dodder attached most slowly to tomato hosts that had dodder plants previously attached and then removed, compared to control plants or plants with continuous dodder attachment. In contrast, herbivory did not affect subsequent dodder attachment rate. These results indicate that dodder preference depended on the identity and the outcome of the initial attack, suggesting that early-season interactions have the potential for profound impacts on subsequent community dynamics. PMID:27529694

  12. Correlated evolution between host immunity and parasite life histories in primates and oxyurid parasites.

    PubMed Central

    Sorci, Gabriele; Skarstein, Frode; Morand, Serge; Hugot, Jean-Pierre

    2003-01-01

    Maturation time is a pivotal life-history trait of parasitic nematodes, determining adult body size, as well as daily and total fecundity. Recent theoretical work has emphasized the influence of prematurational mortality on the optimal values of age and size at maturity in nematodes. Eosinophils are a family of white blood cells often associated with infections by parasitic nematodes. Although the role of eosinophils in nematode resistance is controversial, recent work has suggested that the action of these immune effectors might be limited to the larval stages of the parasite. If eosinophils act on larval survival, one might predict, in line with theoretical models, that nematode species living in hosts with large eosinophil numbers should show reduced age and size at maturity. We tested this prediction using the association between the pinworms (Oxyuridae, Nematoda) and their primate hosts. Pinworms are highly host specific and are expected to be involved in a coevolutionary process with their hosts. We found that the body size of female parasites was negatively correlated with eosinophil concentration, whereas the concentration of two other leucocyte families-neutrophils and lymphocytes-was unrelated to female body size. Egg size of parasites also decreased with host eosinophil concentration, independently of female size. Male body size was unrelated to host immune parameters. Primates with the highest immune defence, therefore, harbour small female pinworms laying small eggs. These results are in agreement with theoretical expectations and suggest that life histories of oxyurid parasites covary with the immune defence of their hosts. Our findings illustrate the potential for host immune defence as a factor driving parasite life-history evolution. PMID:14667339

  13. Parasite Removal, but Not Herbivory, Deters Future Parasite Attachment on Tomato.

    PubMed

    Tjiurutue, Muvari Connie; Palmer-Young, Evan C; Adler, Lynn S

    2016-01-01

    Plants face many antagonistic interactions that occur sequentially. Often, plants employ defense strategies in response to the initial damage that are highly specific and can affect interactions with subsequent antagonists. In addition to herbivores and pathogens, plants face attacks by parasitic plants, but we know little about how prior herbivory compared to prior parasite attachment affects subsequent host interactions. If host plants can respond adaptively to these different damage types, we predict that prior parasitism would have a greater deterrent effect on subsequent parasites than would prior herbivory. To test the effects of prior parasitism and prior herbivory on subsequent parasitic dodder (Cuscuta spp.) preference, we conducted two separate greenhouse studies with tomato hosts (Solanum lycopersicum). In the first experiment, we tested the effects of previous dodder attachment on subsequent dodder preference on tomato hosts using three treatments: control plants that had no previous dodder attachment; dodder-removed plants that had an initial dodder seedling attached, removed and left in the same pot to simulate parasite death; and dodder-continuous plants with an initial dodder seedling that remained attached. In the second experiment, we tested the effects of previous caterpillar damage (Spodoptera exigua) and mechanical damage on future dodder attachment on tomato hosts. Dodder attached most slowly to tomato hosts that had dodder plants previously attached and then removed, compared to control plants or plants with continuous dodder attachment. In contrast, herbivory did not affect subsequent dodder attachment rate. These results indicate that dodder preference depended on the identity and the outcome of the initial attack, suggesting that early-season interactions have the potential for profound impacts on subsequent community dynamics. PMID:27529694

  14. A lack of parasitic reduction in the obligate parasitic green alga Helicosporidium.

    PubMed

    Pombert, Jean-François; Blouin, Nicolas Achille; Lane, Chris; Boucias, Drion; Keeling, Patrick J

    2014-05-01

    The evolution of an obligate parasitic lifestyle is often associated with genomic reduction, in particular with the loss of functions associated with increasing host-dependence. This is evident in many parasites, but perhaps the most extreme transitions are from free-living autotrophic algae to obligate parasites. The best-known examples of this are the apicomplexans such as Plasmodium, which evolved from algae with red secondary plastids. However, an analogous transition also took place independently in the Helicosporidia, where an obligate parasite of animals with an intracellular infection mechanism evolved from algae with green primary plastids. We characterised the nuclear genome of Helicosporidium to compare its transition to parasitism with that of apicomplexans. The Helicosporidium genome is small and compact, even by comparison with the relatively small genomes of the closely related green algae Chlorella and Coccomyxa, but at the functional level we find almost no evidence for reduction. Nearly all ancestral metabolic functions are retained, with the single major exception of photosynthesis, and even here reduction is not complete. The great majority of genes for light-harvesting complexes, photosystems, and pigment biosynthesis have been lost, but those for other photosynthesis-related functions, such as Calvin cycle, are retained. Rather than loss of whole function categories, the predominant reductive force in the Helicosporidium genome is a contraction of gene family complexity, but even here most losses affect families associated with genome maintenance and expression, not functions associated with host-dependence. Other gene families appear to have expanded in response to parasitism, in particular chitinases, including those predicted to digest the chitinous barriers of the insect host or remodel the cell wall of Helicosporidium. Overall, the Helicosporidium genome presents a fascinating picture of the early stages of a transition from free

  15. Parasitic Infestation in Pediatric and Adolescent Appendicitis: A Local Experience

    PubMed Central

    Zakaria, Ossama M.; Zakaria, Hazem M.; Daoud, Mohamed Yasser; Al Wadaani, Hamed; Al Buali, Waleed; Al-Mohammed, Hamdan; Al Mulhim, Abdulrahman S.; Zaki, Wafaa

    2013-01-01

    Objective The relationship between parasites and pediatric appendicitis is a highly debatable issue. This study aims to investigate the role of parasitic infestation in the etiology of acute pediatric appendicitis. Methods A retrospective study including 1600 pediatric and adolescent patients who had undergone surgical therapy for a diagnosis of acute appendicitis over a period of ten years from Jan 2001 to Dec 2010. Demographic data were retrieved including the patient's age, sex, clinical data, clinical presentations, laboratory investigations, operative data and pathological findings to identify the presence and type of parasites. Patients were divided into two groups according to the presence or absence of parasites in the appendix lumen. In group I (n: 88), parasitic infestation was observed, whereas in group II (n: 1502), no parasitic infestation was present. Results Parasites were present in 5.5% (88 patients), and of those 88 parasitic infestations, 45 (51.1%) were Enterobaisis, 8 (9.1%) were Schistosomiasis, 23 (26.1%) were Ascariasis, 7 (8%) Trichuriasis, and 5 (5.7%) were Teania Saginata. The percentage of patients with suppurative, gangrenous or perforated appendicitis was similar in both groups with no statistical significance, irrespective of the presence or absence of parasitic infestation. Conclusion The low prevalence of parasites among the appendectomy specimens did not support the notion that parasites were a major cause of appendicitis in pediatric patients. PMID:23599875

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

    PubMed

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

    2015-02-01

    Plant-parasitic nematodes cause considerable damage to global agriculture. The ability to parasitize plants is a derived character that appears to have independently emerged several times in the phylum Nematoda. Morphological convergence to feeding style has been observed, but whether this is emergent from molecular convergence is less obvious. To address this, we assess whether genomic signatures can be associated with plant parasitism by nematodes. In this review, we report genomic features and characteristics that appear to be common in plant-parasitic nematodes while absent or rare in animal parasites, predators or free-living species. Candidate horizontal acquisitions of parasitism genes have systematically been found in all plant-parasitic species investigated at the sequence level. Presence of peptides that mimic plant hormones also appears to be a trait of plant-parasitic species. Annotations of the few genomes of plant-parasitic nematodes available to date have revealed a set of apparently species-specific genes on every occasion. Effector genes, important for parasitism are frequently found among those species-specific genes, indicating poor overlap. Overall, nematodes appear to have developed convergent genomic solutions to adapt to plant parasitism. PMID:25656361

  17. Coevolution of parasite virulence and host mating strategies

    PubMed Central

    Ashby, Ben; Boots, Michael

    2015-01-01

    Parasites are thought to play an important role in sexual selection and the evolution of mating strategies, which in turn are likely to be critical to the transmission and therefore the evolution of parasites. Despite this clear interdependence we have little understanding of parasite-mediated sexual selection in the context of reciprocal parasite evolution. Here we develop a general coevolutionary model between host mate preference and the virulence of a sexually transmitted parasite. We show when the characteristics of both the host and parasite lead to coevolutionarily stable strategies or runaway selection, and when coevolutionary cycling between high and low levels of host mate choosiness and virulence is possible. A prominent argument against parasites being involved in sexual selection is that they should evolve to become less virulent when transmission depends on host mating success. The present study, however, demonstrates that coevolution can maintain stable host mate choosiness and parasite virulence or indeed coevolutionary cycling of both traits. We predict that choosiness should vary inversely with parasite virulence and that both relatively long and short life spans select against choosy behavior in the host. The model also reveals that hosts can evolve different behavioral responses from the same initial conditions, which highlights difficulties in using comparative analysis to detect parasite-mediated sexual selection. Taken as a whole, our results emphasize the importance of viewing parasite-mediated sexual selection in the context of coevolution. PMID:26430236

  18. Parasites in food webs: the ultimate missing links.

    PubMed

    Lafferty, Kevin D; Allesina, Stefano; Arim, Matias; Briggs, Cherie J; De Leo, Giulio; Dobson, Andrew P; Dunne, Jennifer A; Johnson, Pieter T J; Kuris, Armand M; Marcogliese, David J; Martinez, Neo D; Memmott, Jane; Marquet, Pablo A; McLaughlin, John P; Mordecai, Erin A; Pascual, Mercedes; Poulin, Robert; Thieltges, David W

    2008-06-01

    Parasitism is the most common consumer strategy among organisms, yet only recently has there been a call for the inclusion of infectious disease agents in food webs. The value of this effort hinges on whether parasites affect food-web properties. Increasing evidence suggests that parasites have the potential to uniquely alter food-web topology in terms of chain length, connectance and robustness. In addition, parasites might affect food-web stability, interaction strength and energy flow. Food-web structure also affects infectious disease dynamics because parasites depend on the ecological networks in which they live. Empirically, incorporating parasites into food webs is straightforward. We may start with existing food webs and add parasites as nodes, or we may try to build food webs around systems for which we already have a good understanding of infectious processes. In the future, perhaps researchers will add parasites while they construct food webs. Less clear is how food-web theory can accommodate parasites. This is a deep and central problem in theoretical biology and applied mathematics. For instance, is representing parasites with complex life cycles as a single node equivalent to representing other species with ontogenetic niche shifts as a single node? Can parasitism fit into fundamental frameworks such as the niche model? Can we integrate infectious disease models into the emerging field of dynamic food-web modelling? Future progress will benefit from interdisciplinary collaborations between ecologists and infectious disease biologists. PMID:18462196

  19. Antigenic glycans in parasitic infections: implications for vaccines and diagnostics.

    PubMed

    Nyame, A Kwame; Kawar, Ziad S; Cummings, Richard D

    2004-06-15

    Infections by parasitic protozoans and helminths are a major world-wide health concern, but no vaccines exist to the major human parasitic diseases, such as malaria, African trypanosomiasis, amebiasis, leishmaniasis, schistosomiasis, and lymphatic filariasis. Recent studies on a number of parasites indicate that immune responses to parasites in infected animals and humans are directed to glycan determinants within cell surface and secreted glycoconjugates and that glycoconjugates are important in host-parasite interactions. Because of the tremendous success achieved recently in generating carbohydrate-protein conjugate vaccines toward microbial infections, such as Haemophilus influenzae type b, there is renewed interest in defining parasite-derived glycans in the prospect of developing conjugate vaccines and new diagnostics for parasitic infections. Parasite-derived glycans are compelling vaccine targets because they have structural features that distinguish them from mammalian glycans. There have been exciting new developments in techniques for glycan analysis and the methods for synthesizing oligosaccharides by chemical or combined chemo-enzymatic approaches that now make it feasible to generate parasite glycans to test as vaccine candidates. Here, we highlight recent progress made in elucidating the immunogenicity of glycans from some of the major human and animal parasites, the potential for developing conjugate vaccines for parasitic infections, and the possible utilization of these novel glycans in diagnostics. PMID:15158669

  20. Parasites in food webs: the ultimate missing links

    PubMed Central

    Lafferty, Kevin D; Allesina, Stefano; Arim, Matias; Briggs, Cherie J; De Leo, Giulio; Dobson, Andrew P; Dunne, Jennifer A; Johnson, Pieter T J; Kuris, Armand M; Marcogliese, David J; Martinez, Neo D; Memmott, Jane; Marquet, Pablo A; McLaughlin, John P; Mordecai, Erin A; Pascual, Mercedes; Poulin, Robert; Thieltges, David W

    2008-01-01

    Parasitism is the most common consumer strategy among organisms, yet only recently has there been a call for the inclusion of infectious disease agents in food webs. The value of this effort hinges on whether parasites affect food-web properties. Increasing evidence suggests that parasites have the potential to uniquely alter food-web topology in terms of chain length, connectance and robustness. In addition, parasites might affect food-web stability, interaction strength and energy flow. Food-web structure also affects infectious disease dynamics because parasites depend on the ecological networks in which they live. Empirically, incorporating parasites into food webs is straightforward. We may start with existing food webs and add parasites as nodes, or we may try to build food webs around systems for which we already have a good understanding of infectious processes. In the future, perhaps researchers will add parasites while they construct food webs. Less clear is how food-web theory can accommodate parasites. This is a deep and central problem in theoretical biology and applied mathematics. For instance, is representing parasites with complex life cycles as a single node equivalent to representing other species with ontogenetic niche shifts as a single node? Can parasitism fit into fundamental frameworks such as the niche model? Can we integrate infectious disease models into the emerging field of dynamic food-web modelling? Future progress will benefit from interdisciplinary collaborations between ecologists and infectious disease biologists. PMID:18462196

  1. Diversification and host switching in avian malaria parasites.

    PubMed Central

    Ricklefs, Robert E; Fallon, Sylvia M

    2002-01-01

    The switching of parasitic organisms to novel hosts, in which they may cause the emergence of new diseases, is of great concern to human health and the management of wild and domesticated populations of animals. We used a phylogenetic approach to develop a better statistical assessment of host switching in a large sample of vector-borne malaria parasites of birds (Plasmodium and Haemoproteus) over their history of parasite-host relations. Even with sparse sampling, the number of parasite lineages was almost equal to the number of avian hosts. We found that strongly supported sister lineages of parasites, averaging 1.2% sequence divergence, exhibited highly significant host and geographical fidelity. Event-based matching of host and parasite phylogenetic trees revealed significant cospeciation. However, the accumulated effects of host switching and long distance dispersal cause these signals to disappear before 4% sequence divergence is achieved. Mitochondrial DNA nucleotide substitution appears to occur about three times faster in hosts than in parasites, contrary to findings on other parasite-host systems. Using this mutual calibration, the phylogenies of the parasites and their hosts appear to be similar in age, suggesting that avian malaria parasites diversified along with their modern avian hosts. Although host switching has been a prominent feature over the evolutionary history of avian malaria parasites, it is infrequent and unpredictable on time scales germane to public health and wildlife management. PMID:12028770

  2. Differential Spleen Remodeling Associated with Different Levels of Parasite Virulence Controls Disease Outcome in Malaria Parasite Infections

    PubMed Central

    Huang, Ximei; Huang, Sha; Ong, Lai Chun; Lim, Jason Chu-Shern; Hurst, Rebecca Joan Mary; Mushunje, Annals Tatenda; Matsudaira, Paul Thomas; Han, Jongyoon

    2015-01-01

    ABSTRACT Infections by malaria parasites can lead to very different clinical outcomes, ranging from mild symptoms to death. Differences in the ability of the spleen to deal with the infected red blood cells (iRBCs) are linked to differences in virulence. Using virulent and avirulent strains of the rodent malaria parasite Plasmodium yoelii, we investigated how parasite virulence modulates overall spleen function. Following parasite invasion, a difference in parasite virulence was observed in association with different levels of spleen morphology and iRBC rigidity, both of which contributed to enhanced parasite clearance. Moreover, iRBC rigidity as modulated by the spleen was demonstrated to correlate with disease outcome and thus can be used as a robust indicator of virulence. The data indicate that alterations in the biomechanical properties of iRBCs are the result of the complex interaction between host and parasite. Furthermore, we confirmed that early spleen responses are a key factor in directing the clinical outcome of an infection. IMPORTANCE The spleen and its response to parasite infection are important in eliminating parasites in malaria. By comparing P. yoelii parasite lines with different disease outcomes in mice that had either intact spleens or had had their spleens removed, we showed that upon parasite infection, the spleen exhibits dramatic changes that can affect parasite clearance. The spleen itself directly impacts RBC deformability independently of parasite genetics. The data indicated that the changes in the biomechanical properties of malaria parasite-infected RBCs are the result of the complex interaction between host and parasite, and RBC deformability itself can serve as a novel predictor of clinical outcome. The results also suggest that early responses in the spleen are a key factor directing the clinical outcome of an infection. PMID:27303680

  3. [Views for research development of control of parasitic diseases].

    PubMed

    Zhao, Qin-Ping; Dong, Hui-Fen; Jiang, Ming-Sen

    2013-12-01

    With the social and technological development, new understandings have been emerged for the research development of the control of parasitic diseases. The present review argues that: the traditional point of view for the control of parasitic diseases, eliminating parasites/media, should be updated. For the long-term interests of science and human perspective, biological diversity, including the parasite biodiversity, and ecological environment should be paid much more attention during the control of parasitic diseases. The leading role of society, economy and culture should be fully developed in the control of parasitic diseases with the progress of scientific and technology, to find a final way of sustainable development in the control of parasitic diseases. PMID:24490386

  4. Parasites: what are they good for?

    PubMed Central

    Stumhofer, Jason S.; Loke, P’ng

    2014-01-01

    Parasitic diseases caused by helminth and protozoan infections remain one of the largest global public health problems for mankind. While natural immunity in man is rare or slow to develop for many parasites, the immune response is capable of recognizing and responding to infection by utilizing a number of different immunological mechanisms. This special topics journal issue examines many of the key findings in the recent literature regarding the immune response against helminth and protozoan infections, as well as highlighting areas in which our current knowledge falls short. The question of how we can tailor immune responses to prevent or reduce disease burden is a burning question within the field of immunoparasitology. PMID:24683385

  5. Metazoan parasites of dogs in Sabah, Malaysia.

    PubMed

    MacAdam, I; Gudan, D; Timbs, D V; Urquhart, H R; Sewell, M M

    1984-02-01

    The parasites which occurred most frequently in 175 owned or stray dogs in Sabah were Ancylostoma spp. present in 68% of the animals. Dirofilaria immitis occurred in 70% of the adult dogs but neither D. immitis nor Spirocerca lupi were present in puppies under four months of age. The latter attained a prevalence of 30% in the adults. In contrast Toxocara canis occurred in 81% of the puppies but infrequently in older dogs. Dipylidium caninum was moderately prevalent (15 to 25%) in dogs of all ages. Ticks were the most common arthropod parasite being present on 26% of the dogs and were mainly Rhipicephalus sanguineus. Demodectic and sarcoptic mange were confirmed and fleas and lice were also recovered. PMID:6730003

  6. Cytopathology of parasitic dermatitis in dogs.

    PubMed

    Sood, N K; Mekkib, Berhanu; Singla, L D; Gupta, K

    2012-04-01

    Out of 44 cases of dermatitis in dogs, 11 cases of parasitic origin were analyzed by cytopathology. Histopathologic examination of punch biopsies was also done for correlation with cytologic findings. Sarcoptic dermatitis was recorded in six cases, wherein, besides sarcoptic mites, neutrophils, macrophages, and plasma cells and keratinizing epithelial cells were also seen. Hematology revealed a relative neutrophilia and mild eosinophilia. Four cases of severe and generalized demodicosis complicated with bacteria and/or Malassezia sp. infection were also recorded. Histopathologically numerous Demodex sp. mites in varying stage of maturation were found damaging the hair follicles along with associated pathological changes and foreign body granulomas in one case. In addition, flea allergy dermatitis was also observed in one dog. In nutshell, cytology was found to be unequivocally effective in diagnosing parasitic dermatitis. PMID:23543297

  7. Topoisomerases of kinetoplastid parasites: why so fascinating?

    PubMed

    Das, Benu Brata; Sengupta, Tanushri; Ganguly, Agneyo; Majumder, Hemanta K

    2006-11-01

    DNA topoisomerases are the key enzymes involved in carrying out high precision DNA transactions inside the cells. However, they are detrimental to the cell when a wide variety of topoisomerase-targeted drugs generate cytotoxic lesions by trapping the enzymes in covalent complexes on the DNA. The discovery of unusual heterodimeric topoisomerase I in kinetoplastid family added a new twist in topoisomerase research related to evolution, functional conservation and their preferential sensitivity to Camptothecin. On the other hand, structural and mechanistic studies on kinetoplastid topoisomerase II delineate some distinguishing features that differentiate the parasitic enzyme from its prokaryotic and eukaryotic counterparts. This review summarizes the recent advances in research in kinetoplastid topoisomerases, their evolutionary significance and the death of the unicellular parasite Leishmania donovani induced by topoisomerase I inhibitor camptothecin. PMID:17042788

  8. Fruit Flies Medicate Offspring After Seeing Parasites

    PubMed Central

    Kacsoh, Balint Z.; Lynch, Zachary R.; Mortimer, Nathan T.; Schlenke, Todd A.

    2013-01-01

    Hosts have numerous defenses against parasites, of which behavioral immune responses are an important but under-appreciated component. Here we describe a behavioral immune response Drosophila melanogaster utilizes against endoparasitoid wasps. We found that when flies see wasps they switch to laying eggs in alcohol-laden food sources that protect hatched larvae from infection. This oviposition behavior change, mediated by neuropeptide F, is retained long after wasps are removed. Flies respond to diverse female larval endoparasitoids but not to pupal endoparasitoids or males, showing they maintain specific wasp search images. Furthermore, the response evolved multiple times across the genus Drosophila. Our data reveal a behavioral immune response based on anticipatory medication of offspring, and outline a non-associative memory paradigm based on innate parasite recognition by the host. PMID:23430653

  9. Optical tweezers for studying taxis in parasites

    NASA Astrophysics Data System (ADS)

    de Thomaz, A. A.; Fontes, A.; Stahl, C. V.; Pozzo, L. Y.; Ayres, D. C.; Almeida, D. B.; Farias, P. M. A.; Santos, B. S.; Santos-Mallet, J.; Gomes, S. A. O.; Giorgio, S.; Feder, D.; Cesar, C. L.

    2011-04-01

    In this work we present a methodology to measure force strengths and directions of living parasites with an optical tweezers setup. These measurements were used to study the parasites chemotaxis in real time. We observed behavior and measured the force of: (i) Leishmania amazonensis in the presence of two glucose gradients; (ii) Trypanosoma cruzi in the vicinity of the digestive system walls, and (iii) Trypanosoma rangeli in the vicinity of salivary glands as a function of distance. Our results clearly show a chemotactic behavior in every case. This methodology can be used to study any type of taxis, such as chemotaxis, osmotaxis, thermotaxis, phototaxis, of any kind of living microorganisms. These studies can help us to understand the microorganism sensory systems and their response function to these gradients.

  10. Lateralized courtship in a parasitic wasp.

    PubMed

    Romano, Donato; Donati, Elisa; Canale, Angelo; Messing, Russell H; Benelli, Giovanni; Stefanini, Cesare

    2016-05-01

    Lateralization (i.e. left-right asymmetries in the brain and behaviour) of courtship displays has been examined in a growing number vertebrate species, while evidence for invertebrates is limited. In this study, we investigated lateralization of courtship and mating displays in the parasitic wasp Leptomastidea abnormis. Results showed a population-level lateralization of male courtship displays. Male antennal tapping on the female's head was right-biased. However, right-biased male courtship acts were not characterized by higher male antennal tapping frequencies, nor success in mating although antennal tapping frequency was higher in males with mating success with respect to unsuccessful males. Overall, our results add basic knowledge to the behavioural ecology of insect parasitoids. To the best of our knowledge, this is the first report of behavioural lateralization in parasitic Hymenoptera. PMID:26932864

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

    PubMed

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

    2010-07-01

    The central theme of Shakespeare's Romeo and Juliet is that names are meaningless, artificial constructs, detached from any underlying reality. By contrast, we argue that a well chosen gene name can concisely convey a wealth of relevant biological information. A consistent nomenclature adds transparency that can have a real impact on our understanding of gene function. Currently, genes in parasitic nematodes are often named ad hoc, leading to confusion that can be resolved by adherence to a nomenclature standard adapted from Caenorhabditis elegans. We demonstrate this with ligand-gated ion-channels and propose that the flood of genome data and differences between parasites and the free living C. elegans will require modification of the standard. PMID:20478743

  12. A naked ape would have fewer parasites.

    PubMed

    Pagel, Mark; Bodmer, Walter

    2003-08-01

    Unusually among the mammals, humans lack an outer layer of protective fur or hair. We propose the hypothesis that humans evolved hairlessness to reduce parasite loads, especially ectoparasites that may carry disease. We suggest that hairlessness is maintained by these naturally selected benefits and by sexual selection operating on both sexes. Hairlessness is made possible in humans owing to their unique abilities to regulate their environment via fire, shelter and clothing. Clothes and shelters allow a more flexible response to the external environment than a permanent layer of fur and can be changed or cleaned if infested with parasites. Naked molerats, another hairless and non-aquatic mammal species, also inhabit environments in which ectoparasite transmission is expected to be high, but in which temperatures are closely regulated. Our hypothesis explains features of human hairlessness-such as the marked sex difference in body hair, and its retention in the pubic regions-that are not explained by other theories. PMID:12952654

  13. Repetitive Elements in Genomes of Parasitic Protozoa

    PubMed Central

    Wickstead, Bill; Ersfeld, Klaus; Gull, Keith

    2003-01-01

    Repetitive DNA elements have been a part of the genomic fauna of eukaryotes perhaps since their very beginnings. Millions of years of coevolution have given repeats central roles in chromosome maintenance and genetic modulation. Here we review the genomes of parasitic protozoa in the context of the current understanding of repetitive elements. Particular reference is made to repeats in five medically important species with ongoing or completed genome sequencing projects: Plasmodium falciparum, Leishmania major, Trypanosoma brucei, Trypanosoma cruzi, and Giardia lamblia. These organisms are used to illustrate five thematic classes of repeats with different structures and genomic locations. We discuss how these repeat classes may interact with parasitic life-style and also how they can be used as experimental tools. The story which emerges is one of opportunism and upheaval which have been employed to add genetic diversity and genomic flexibility. PMID:12966140

  14. [Heterogeneity of parasitic contamination of megalopolis soils].

    PubMed

    Aliautdinova, L V; Semenova, T A; Zavoĭkin, V D

    2011-01-01

    A morphological group ofwhipworm (Trichuris trichiura) eggs, which is detectable in the soil samples from the city's different control lands, shows that their origin is heterogeneous and it is possible to differentiate them by morphometric signs. At the same time is necessary to consider the specific biological factors contributing to soil contamination. Priority in parasitic soil contamination should be given to animals, dogs in particular, which is supported by the fact that the dog walking grounds exhibit the highest contamination rates. PMID:21797059

  15. Blood parasites of shrews from Pennsylvania.

    PubMed

    Laakkonen, J; Haukisalmi, V; Merritt, J F

    1998-12-01

    We examined 30 Sorex cinereus, 5 Sorex fumeus, and 21 Blarina brevicauda collected from Pennsylvania in 1995 for blood parasites. Trypomastigotes of Trypanosoma sp. were visible in 13% of the S. cinereus. Ten percent of S. cinereus, 20% of S. fumeus, and 14% of B. brevicauda were infected with Bartonella sp. (or spp.). In S. cinereus, we detected no concurrent Trypanosoma and Bartonella infections. PMID:9920338

  16. Intestinal parasites in man in Labrador, Canada.

    PubMed

    Sole, T D; Croll, N A

    1980-05-01

    Labrador, a previously unsurveyed area of Canada, has been sampled for human intestinal parasites. Four hundred and one asymptomatic volunteers between 1 and 72 years of age, including Inuit, Naskapi and whites, were examined during the summer of 1977. They harboured: Entamoeba coli, E. histolytica, E. hartmanni, Giardia lamblia and Diphyllobothrium sp. The infection rates are considerably lower than those found in other studies of Northern Canadian communities. PMID:6966896

  17. Parasite stress, ethnocentrism, and life history strategy.

    PubMed

    Figueredo, Aurelio José; Gladden, Paul Robert; Black, Candace Jasmine

    2012-04-01

    Fincher & Thornhill (F&T) present a compelling argument that parasite stress underlies certain cultural practices promoting assortative sociality. However, we suggest that the theoretical framework proposed is limited in several ways, and that life history theory provides a more explanatory and inclusive framework, making more specific predictions about the trade-offs faced by organisms in the allocation of bioenergetic and material resources. PMID:22289411

  18. Complex Daphnia interactions with parasites and competitors.

    PubMed

    Cáceres, C E; Davis, G; Duple, S; Hall, S R; Koss, A; Lee, P; Rapti, Z

    2014-12-01

    Species interactions can strongly influence the size and dynamics of epidemics in populations of focal hosts. The "dilution effect" provides a particularly interesting type of interaction from a biological standpoint. Diluters - other host species which resist infection but remove environmentally-distributed propagules of parasites (spores) - should reduce disease prevalence in focal hosts. However, diluters and focal hosts may compete for shared resources. This combination of positive (dilution) and negative (competition) effects could greatly complicate, even undermine, the benefits of dilution and diluter species from the perspective of the focal host. Motivated by an example from the plankton (i.e., zooplankton hosts, a fungal parasite, and algal resources), we study a model of dilution and competition. Our model reveals a suite of five results: • A diluter that is a superior competitor wipes out the host, regardless of parasitism. Although expected, this outcome is an ever-present danger in strategies that might use diluters to control disease. • If the diluter is an inferior competitor, it can reduce disease prevalence, despite the competition, as parameterized in our model. However, competition may also reduce density of susceptible hosts to levels below that seen in focal host-parasite systems alone. • As they decrease disease prevalence, diluters destabilize dynamics of the focal host and their resources. Thus, diluters undermine the stabilizing effects of disease. • The four species combination can generate very complex dynamics, including period-doubling bifurcations and torus (Neimark-Sacker) bifurcations. • At lower resource carrying capacity, the diluter’s dilution of spores is 'helpful' to the focal host, i.e., dilution can elevate host density by reducing disease. But, as the resource carrying capacity increases further, the equilibrium density of the diluter increases while the density of the focal host decreases, despite competition

  19. Parasitism, community structure and biodiversity in intertidal ecosystems.

    PubMed

    Mouritsen, K N; Poulin, R

    2002-01-01

    There is mounting evidence that parasites can influence the composition and structure of natural animal communities. In spite of this, it is difficult to assess just how important parasitism is for community structure because very few studies have been designed specifically to address the role of parasites at the community level, no doubt because it is difficult to manipulate the abundance of parasites in field experiments. Here, we bring together a large amount of published information on parasitism in intertidal communities to highlight the potential influence of parasites on the structure and biodiversity of these communities. We first review the impact of metazoan parasites on the survival, reproduction, growth and behaviour of intertidal invertebrates, from both rocky shores and soft-sediment flats. Published evidence suggests that the impact of parasites on individuals is often severe, though their effects at the population level are dependent on prevalence and intensity of infection. We then put this information together in a discussion of the impact of parasitism at the community level. We emphasize two ways in which parasites can modify the structure of intertidal communities. First, the direct impact of parasites on the abundance of key host species can decrease the importance of these hosts in competition or predator-prey interactions with other species. Second, the indirect effects of parasites on the behaviour of their hosts, e.g. burrowing ability or spatial distribution within the intertidal zone, can cause changes to various features of the habitat for other intertidal species, leading to their greater settlement success or to their local disappearance. Our synthesis allows specific predictions to be made regarding the potential impact of parasites in certain intertidal systems, and suggests that parasites must be included in future community studies and food web models of intertidal ecosystems. PMID:12396219

  20. Parasitic infection: a buffer against ocean acidification?

    PubMed

    MacLeod, Colin D; Poulin, Robert

    2016-05-01

    Recently, there has been a concerted research effort by marine scientists to quantify the sensitivity of marine organisms to ocean acidification (OA). Empirical data generated by this research have been used to predict changes to marine ecosystem health, biodiversity and productivity that will be caused by continued acidification. These studies have also found that the effects of OA on marine organisms can be significantly modified by additional abiotic stressors (e.g. temperature or oxygen) and biotic interactions (e.g. competition or predation). To date, however, the effects of parasitic infection on the sensitivity of marine organisms to OA have been largely ignored. We show that parasitic infection significantly altered the response of a marine gastropod to simulated OA conditions by reducing the mortality of infected individuals relative to uninfected conspecifics. Without the inclusion of infection data, our analysis would not have detected the significant effect of pH on host mortality. These results strongly suggest that parasitic infection may be an important confounding factor in OA research and must be taken into consideration when assessing the response of marine species to OA. PMID:27194286

  1. Sushi in pregnancy, parasitic diseases - obstetrician survey.

    PubMed

    Jones, J L; Anderson, B; Schulkin, J; Parise, M E; Eberhard, M L

    2011-03-01

    Parasites from raw fish can lead to a wide range of clinical manifestations and can be challenging to treat in pregnancy as result of medication exposure of the foetus. We surveyed obstetrician-gynecologists (ob-gyns) in the U.S. to determine their knowledge about the consumption of raw fish during pregnancy. In March 2007, a questionnaire was mailed to members of the American College of Obstetricians and Gynecologists (ACOG) randomly selected to represent all members. Non-responding physicians were sent two additional mailings. Of the 606 ACOG members surveyed, 305 (50%) responded. Most (82%) respondents indicated that eating raw fish is not safe during pregnancy. However, few (19%) knew that thorough freezing kills parasites in fish. Nearly all (94%) respondents thought that parasitic infections can be more challenging to treat in pregnancy. U.S. ob-gyns believe that eating raw fish during pregnancy is not safe; most would benefit from information about how to prevent infection and about treatment. PMID:20042060

  2. Fungal and Parasitic Infections of the Eye

    PubMed Central

    Klotz, Stephen A.; Penn, Christopher C.; Negvesky, Gerald J.; Butrus, Salim I.

    2000-01-01

    The unique structure of the human eye as well as exposure of the eye directly to the environment renders it vulnerable to a number of uncommon infectious diseases caused by fungi and parasites. Host defenses directed against these microorganisms, once anatomical barriers are breached, are often insufficient to prevent loss of vision. Therefore, the timely identification and treatment of the involved microorganisms are paramount. The anatomy of the eye and its surrounding structures is presented with an emphasis upon the association of the anatomy with specific infection of fungi and parasites. For example, filamentous fungal infections of the eye are usually due to penetrating trauma by objects contaminated by vegetable matter of the cornea or globe or, by extension, of infection from adjacent paranasal sinuses. Fungal endophthalmitis and chorioretinitis, on the other hand, are usually the result of antecedent fungemia seeding the ocular tissue. Candida spp. are the most common cause of endogenous endophthalmitis, although initial infection with the dimorphic fungi may lead to infection and scarring of the chorioretina. Contact lens wear is associated with keratitis caused by yeasts, filamentous fungi, and Acanthamoebae spp. Most parasitic infections of the eye, however, arise following bloodborne carriage of the microorganism to the eye or adjacent structures. PMID:11023963

  3. Bacterial, Fungal, Parasitic, and Viral Myositis

    PubMed Central

    Crum-Cianflone, Nancy F.

    2008-01-01

    Infectious myositis may be caused by a broad range of bacterial, fungal, parasitic, and viral agents. Infectious myositis is overall uncommon given the relative resistance of the musculature to infection. For example, inciting events, including trauma, surgery, or the presence of foreign bodies or devitalized tissue, are often present in cases of bacterial myositis. Bacterial causes are categorized by clinical presentation, anatomic location, and causative organisms into the categories of pyomyositis, psoas abscess, Staphylococcus aureus myositis, group A streptococcal necrotizing myositis, group B streptococcal myositis, clostridial gas gangrene, and nonclostridial myositis. Fungal myositis is rare and usually occurs among immunocompromised hosts. Parasitic myositis is most commonly a result of trichinosis or cystericercosis, but other protozoa or helminths may be involved. A parasitic cause of myositis is suggested by the travel history and presence of eosinophilia. Viruses may cause diffuse muscle involvement with clinical manifestations, such as benign acute myositis (most commonly due to influenza virus), pleurodynia (coxsackievirus B), acute rhabdomyolysis, or an immune-mediated polymyositis. The diagnosis of myositis is suggested by the clinical picture and radiologic imaging, and the etiologic agent is confirmed by microbiologic or serologic testing. Therapy is based on the clinical presentation and the underlying pathogen. PMID:18625683

  4. Invasion and Intracellular Survival by Protozoan Parasites

    PubMed Central

    Sibley, L. David

    2013-01-01

    Summary Intracellular parasitism has arisen only a few times during the long ancestry of protozoan parasites including in diverse groups such as microsporidians, kinetoplastids, and apicomplexans. Strategies used to gain entry differ widely from injection (e.g. microsporidians), active penetration of the host cell (e.g. Toxoplasma), recruitment of lysosomes to a plasma membrane wound (e.g. Trypanosoma cruzi), to host cell-mediated phagocytosis (e.g. Leishmania). The resulting range of intracellular niches is equally diverse ranging from cytosolic (e.g. T. cruzi) to residing within a nonfusigenic vacuole (e.g. Toxoplasma, Encephalitizoon) or a modified phagolysosome (e.g. Leishmania). These lifestyle choices influence access to nutrients, interaction with host cell signaling pathways, and detection by pathogen recognition systems. As such, intracellular life requires a repertoire of adaptations to assure entry-exit from the cell, as well as to thwart innate immune mechanisms and prevent clearance. Elucidating these pathways at the cellular and molecular level may identify key steps that can be targeted to reduce parasite survival or augment immunological responses and thereby prevent disease. PMID:21349087

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

    PubMed Central

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

    2015-01-01

    Since its introduction in France 10 years ago, the yellow-legged Asian bee-hawking hornet Vespa velutina has rapidly spread to neighboring countries (Spain, Portugal, Belgium, Italy, and Germany), becoming a new threat to beekeeping activities. While introduced species often leave behind natural enemies from their original home, which benefits them in their new environment, they can also suffer local recruitment of natural enemies. Three mermithid parasitic subadults were obtained from V. velutina adults in 2012, from two French localities. However, these were the only parasitic nematodes reported up to now in Europe, in spite of the huge numbers of nests destroyed each year and the recent examination of 33,000 adult hornets. This suggests that the infection of V. velutina by these nematodes is exceptional. Morphological criteria assigned the specimens to the genus Pheromermis and molecular data (18S sequences) to the Mermithidae, due to the lack of Pheromermis spp. sequences in GenBank. The species is probably Pheromermis vesparum, a parasite of social wasps in Europe. This nematode is the second native enemy of Vespa velutina recorded in France, after a conopid fly whose larvae develop as internal parasitoids of adult wasps and bumblebees. In this paper, we provide arguments for the local origin of the nematode parasite and its limited impact on hornet colony survival. We also clarify why these parasites (mermithids and conopids) most likely could not hamper the hornet invasion nor be used in biological control programs against this invasive species. PMID:26038716

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

    PubMed

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

    2015-01-01

    Since its introduction in France 10 years ago, the yellow-legged Asian bee-hawking hornet Vespa velutina has rapidly spread to neighboring countries (Spain, Portugal, Belgium, Italy, and Germany), becoming a new threat to beekeeping activities. While introduced species often leave behind natural enemies from their original home, which benefits them in their new environment, they can also suffer local recruitment of natural enemies. Three mermithid parasitic subadults were obtained from V. velutina adults in 2012, from two French localities. However, these were the only parasitic nematodes reported up to now in Europe, in spite of the huge numbers of nests destroyed each year and the recent examination of 33,000 adult hornets. This suggests that the infection of V. velutina by these nematodes is exceptional. Morphological criteria assigned the specimens to the genus Pheromermis and molecular data (18S sequences) to the Mermithidae, due to the lack of Pheromermis spp. sequences in GenBank. The species is probably Pheromermis vesparum, a parasite of social wasps in Europe. This nematode is the second native enemy of Vespa velutina recorded in France, after a conopid fly whose larvae develop as internal parasitoids of adult wasps and bumblebees. In this paper, we provide arguments for the local origin of the nematode parasite and its limited impact on hornet colony survival. We also clarify why these parasites (mermithids and conopids) most likely could not hamper the hornet invasion nor be used in biological control programs against this invasive species. PMID:26038716

  7. When Parasites Are Good for Health: Cestode Parasitism Increases Resistance to Arsenic in Brine Shrimps.

    PubMed

    Sánchez, Marta I; Pons, Inès; Martínez-Haro, Mónica; Taggart, Mark A; Lenormand, Thomas; Green, Andy J

    2016-03-01

    Parasites and pollutants can both affect any living organism, and their interactions can be very important. To date, repeated studies have found that parasites and heavy metals or metalloids both have important negative effects on the health of animals, often in a synergistic manner. Here, we show for the first time that parasites can increase host resistance to metalloid arsenic, focusing on a clonal population of brine shrimp from the contaminated Odiel and Tinto estuary in SW Spain. We studied the effect of cestodes on the response of Artemia to arsenic (acute toxicity tests, 24h LC50) and found that infection consistently reduced mortality across a range of arsenic concentrations. An increase from 25°C to 29°C, simulating the change in mean temperature expected under climate change, increased arsenic toxicity, but the benefits of infection persisted. Infected individuals showed higher levels of catalase and glutathione reductase activity, antioxidant enzymes with a very important role in the protection against oxidative stress. Levels of TBARS were unaffected by parasites, suggesting that infection is not associated with oxidative damage. Moreover, infected Artemia had a higher number of carotenoid-rich lipid droplets which may also protect the host through the "survival of the fattest" principle and the antioxidant potential of carotenoids. This study illustrates the need to consider the multi-stress context (contaminants and temperature increase) in which host-parasite interactions occur. PMID:26938743

  8. Host-parasite relatedness shown by protein fingerprinting in a brood parasitic bird.

    PubMed

    Andersson, M; Ahlund, M

    2000-11-21

    Brood parasitism as an alternative female breeding tactic is particularly common in ducks, where hosts often receive eggs laid by parasitic females of the same species and raise their offspring. Herein, we test several aspects of a kin selection explanation for this phenomenon in goldeneye ducks (Bucephala clangula) by using techniques of egg albumen sampling and statistical bandsharing analysis based on resampling. We find that host and primary parasite are indeed often related, with mean r = 0.13, about as high as between first cousins. Relatedness to the host is higher in nests where a parasite lays several eggs than in those where she lays only one. Returning young females parasitize their birth nestmates (social mothers or sisters, which are usually also their genetic mothers and sisters) more often than expected by chance. Such adult relatives are also observed together in the field more often than expected and for longer periods than other females. Relatedness and kin discrimination, which can be achieved by recognition of birth nestmates, therefore play a role in these tactics and probably influence their success. PMID:11050150

  9. Heightened exposure to parasites favors the evolution of immunity in brood parasitic cowbirds

    USGS Publications Warehouse

    Hahn, Caldwell; Reisen, William K.

    2011-01-01

    Immunologists and evolutionary biologists are interested in how the immune system evolves to fit an ecological niche. We studied the relationship between exposure to parasites and strength of immunity by investigating the response of two species of New World cowbirds (genus Molothrus, Icteridae), obligate brood parasites with contrasting life history strategies, to experimental arboviral infection. The South American shiny cowbird (M. bonariensis) is an extreme host-generalist that lays its eggs in the nests of >225 different avian species. The Central American bronzed cowbird (M. aeneus) is a relative host-specialist that lays its eggs preferentially in the nests of approximately 12 orioles in a single sister genus. West Nile virus provided a strong challenge and delineated immune differences between these species. The extreme host-generalist shiny cowbird, like the North American host-generalist, the brown-headed cowbird, showed significantly lower viremia to three arboviruses than related icterid species that were not brood parasites. The bronzed cowbird showed intermediate viremia. These findings support the interpretation that repeated exposure to a high diversity of parasites favors the evolution of enhanced immunity in brood parasitic cowbirds and makes them useful models for future studies of innate immunity.

  10. When Parasites Are Good for Health: Cestode Parasitism Increases Resistance to Arsenic in Brine Shrimps

    PubMed Central

    Martínez-Haro, Mónica; Taggart, Mark A.; Lenormand, Thomas; Green, Andy J.

    2016-01-01

    Parasites and pollutants can both affect any living organism, and their interactions can be very important. To date, repeated studies have found that parasites and heavy metals or metalloids both have important negative effects on the health of animals, often in a synergistic manner. Here, we show for the first time that parasites can increase host resistance to metalloid arsenic, focusing on a clonal population of brine shrimp from the contaminated Odiel and Tinto estuary in SW Spain. We studied the effect of cestodes on the response of Artemia to arsenic (acute toxicity tests, 24h LC50) and found that infection consistently reduced mortality across a range of arsenic concentrations. An increase from 25°C to 29°C, simulating the change in mean temperature expected under climate change, increased arsenic toxicity, but the benefits of infection persisted. Infected individuals showed higher levels of catalase and glutathione reductase activity, antioxidant enzymes with a very important role in the protection against oxidative stress. Levels of TBARS were unaffected by parasites, suggesting that infection is not associated with oxidative damage. Moreover, infected Artemia had a higher number of carotenoid-rich lipid droplets which may also protect the host through the “survival of the fattest” principle and the antioxidant potential of carotenoids. This study illustrates the need to consider the multi-stress context (contaminants and temperature increase) in which host-parasite interactions occur. PMID:26938743

  11. Trypanosomatid comparative genomics: Contributions to the study of parasite biology and different parasitic diseases

    PubMed Central

    Teixeira, Santuza M.; de Paiva, Rita Márcia Cardoso; Kangussu-Marcolino, Monica M.; DaRocha, Wanderson D.

    2012-01-01

    In 2005, draft sequences of the genomes of Trypanosoma brucei, Trypanosoma cruzi and Leishmania major, also known as the Tri-Tryp genomes, were published. These protozoan parasites are the causative agents of three distinct insect-borne diseases, namely sleeping sickness, Chagas disease and leishmaniasis, all with a worldwide distribution. Despite the large estimated evolutionary distance among them, a conserved core of ~6,200 trypanosomatid genes was found among the Tri-Tryp genomes. Extensive analysis of these genomic sequences has greatly increased our understanding of the biology of these parasites and their host-parasite interactions. In this article, we review the recent advances in the comparative genomics of these three species. This analysis also includes data on additional sequences derived from other trypanosmatid species, as well as recent data on gene expression and functional genomics. In addition to facilitating the identification of key parasite molecules that may provide a better understanding of these complex diseases, genome studies offer a rich source of new information that can be used to define potential new drug targets and vaccine candidates for controlling these parasitic infections. PMID:22481868

  12. Monoclonal antibody against recombinant Fasciola gigantica cathepsin L1H could detect juvenile and adult cathepsin Ls of Fasciola gigantica.

    PubMed

    Wongwairot, Sirima; Kueakhai, Pornanan; Changklungmoa, Narin; Jaikua, Wipaphorn; Sansri, Veerawat; Meemon, Krai; Songkoomkrong, Sineenart; Riengrojpitak, Suda; Sobhon, Prasert

    2015-01-01

    Cathepsin Ls (CatLs), the major cysteine protease secreted by Fasciola spp., are important for parasite digestion and tissue invasion. Fasciola gigantica cathepsin L1H (FgCatL1H) is the isotype expressed in the early stages for migration and invasion. In the present study, a monoclonal antibody (MoAb) against recombinant F. gigantica cathepsin L1H (rFgCatL1H) was produced by hybridoma technique using spleen cells from BALB/c mice immunized with recombinant proFgCatL1H (rproFgCatL1H). This MoAb is an immunoglobulin (Ig)G1 with κ light chain isotype. The MoAb reacted specifically with rproFgCatL1H, the native FgCatL1H at a molecular weight (MW) 38 to 48 kDa in the extract of whole body (WB) of metacercariae and newly excysted juvenile (NEJ) and cross-reacted with rFgCatL1 and native FgCatLs at MW 25 to 28 kDa in WB of 2- and 4-week-old juveniles, adult, and adult excretory-secretory (ES) fractions by immunoblotting and indirect ELISA. It did not cross-react with antigens in WB fractions from other parasites, including Gigantocotyle explanatum, Paramphistomum cervi, Gastrothylax crumenifer, Eurytrema pancreaticum, Setaria labiato-papillosa, and Fischoederius cobboldi. By immunolocalization, MoAb against rFgCatL1H reacted with the native protein in the gut of metacercariae and NEJ and also cross-reacted with CatL1 in 2- and 4-week-old juveniles and adult F. gigantica. Therefore, FgCatL1H and its MoAb may be used for immunodiagnosis of both early and late fasciolosis in ruminants and humans. PMID:25324133

  13. Multiple parasitic crustacean infestation on belonid fish Strongylura strongylura

    PubMed Central

    Aneesh, Panakkool-Thamban; Sudha, Kappalli; Helna, Ameri Kottarathil; Anilkumar, Gopinathan; Trilles, Jean-Paul

    2014-01-01

    Abstract Simultaneous multiple infestation of parasitic crustacean species involving a cymothoid isopod, Cymothoa frontalis Milne Edward, 1840 and four species of copepods such as Lernanthropus tylosuri Richiardi, 1880, Caligodes lacinatus Kroyer, 1863, Bomolochus bellones Burmeister, 1833 and Dermoergasilus coleus Cressey & Collette, 1970 was frequently noticed on spot-tail needlefish, Strongylura strongylura (Belonidae) captured from the Malabar coast (Kerala, India) during the period from April 2011 to March 2012. All the 43 fishes (Strongylura strongylura) collected, were under the hyper-infection with parasitic crustaceans; a total of 388 parasitic crustaceans including 57 Cymothoa frontalis, 252 Lernanthropus tylosuri, 31 Caligodes lacinatus, 24 Bomolochus bellones and 32 Dermoergasilus coleus were recovered from the host fish. 4 members (9.30%) of host fish were under quadruple parasitism, in two different combinations. Seventeen (39.53%) host fishes showed triple parasitism and 20 (46.51%) members exhibited double parasitism, with four and five parasitic combinations respectively. Remaining two (4.65%) fishes were parasitized only by the copepod, Lernanthropus tylosuri. The infestations by all recovered parasitic crustaceans were highly site specific. The damage caused by the parasitic crustaceans was also discussed. PMID:25561846

  14. Parasite adaptation to extreme conditions in a desert environment.

    PubMed

    Tinsley, R C

    1999-01-01

    Deserts represent universally recognized extreme environments for animal life. This paper documents the highly specialized adaptations of Pseudodiplorchis americanus, a monogenean parasite of the desert toad, Scaphiopus couchii. Building on a long-term record of parasite population ecology (continuing since the early 1980s), field studies focus on the effects of severe drought in the Sonoran Desert, Arizona, in the mid 1990s. This provides a test of the ability of the host-parasite system to tolerate exceptional perturbation. The analysis provides new insight into parasite infection dynamics in a natural wildlife system through integration of host and parasite population age structure. The environmental check interrupted host recruitment in 1993-95 and parasite recruitment in 1995-97. This produced an imprint in age structure and infection levels recognizable over several years: parasite recruitment failure reduced transmission 2-3 years later. The host (maximum life span 17 years) tolerated the disruption but the impact was more serious for the parasite (life span 3 years) leading to extinction of some previously stable populations. Despite this demonstration of a rare event exacerbating external environmental constraints, experimental studies suggest that the internal (host) environment normally creates the most severe conditions affecting P. americanus. Only about 3% of parasites survive from invasion until first reproduction. Post-invasion factors including host immunity, characteristic of most parasite life cycles, constitute a greater constraint upon survival than external conditions, even in a desert environment. PMID:11254147

  15. Nematodes, bacteria, and flies: a tripartite model for nematode parasitism.

    PubMed

    Hallem, Elissa A; Rengarajan, Michelle; Ciche, Todd A; Sternberg, Paul W

    2007-05-15

    More than a quarter of the world's population is infected with nematode parasites, and more than a hundred species of nematodes are parasites of humans [1-3]. Despite extensive morbidity and mortality caused by nematode parasites, the biological mechanisms of host-parasite interactions are poorly understood, largely because of the lack of genetically tractable model systems. We have demonstrated that the insect parasitic nematode Heterorhabditis bacteriophora, its bacterial symbiont Photorhabdus luminescens, and the fruit fly Drosophila melanogaster constitute a tripartite model for nematode parasitism and parasitic infection. We find that infective juveniles (IJs) of Heterorhabditis, which contain Photorhabdus in their gut, can infect and kill Drosophila larvae. We show that infection activates an immune response in Drosophila that results in the temporally dynamic expression of a subset of antimicrobial peptide (AMP) genes, and that this immune response is induced specifically by Photorhabdus. We also investigated the cellular and molecular mechanisms underlying IJ recovery, the developmental process that occurs in parasitic nematodes upon host invasion and that is necessary for successful parasitism. We find that the chemosensory neurons and signaling pathways that control dauer recovery in Caenorhabditis elegans also control IJ recovery in Heterorhabditis, suggesting conservation of these developmental processes across free-living and parasitic nematodes. PMID:17475494

  16. Shiny cowbird parasitism in two avian communities in Puerto Rico

    USGS Publications Warehouse

    Wiley, J.W.

    1985-01-01

    The shiny cowbird (M. bonariensis), a brood parasite, has recently expanded its range from South America to Puerto Rico via the Lesser Antilles. This species is a host generalist and, on reaching Puerto Rico, encounteed avian species with no history of social parasitism. In mangrove habitat study areas, 42% of the resident non-raptorial land bird species were parasitized. Some species were heavily parasitized; e.g., yellow warbler (Dendroica petechia), 76% of nests parasitized black-whiskered vireo (Vireo altiloquus), 82%, Puerto Rican flycatcher (Myiarchus antillarum), 85%, yellow-shouldered blackbird (Agelaius xanthomus), 95%, troupial (Icterus icterus), 100%, black-cowled oriole (I. dominicensis), 100%. Others suffered low rates of parasitism (2-17% of nests examined); e.g., gray kingbird (Tyrannus dominicensis), red-legged thrush (Turdus plumbeus), bronze mannikin (Lonchura cucullata), northern mockingbird (Mimus polyglottos), greater antillean grackle (Quiscalus niger). Cowbird parasitism affected hosts by depressing nest success an average of 41% below non-parasitized nests and reducing host productivity. Parasitized host nests hatched 12% fewer eggs an fledged 67% fewer of their own chicks than non-parasitized pairs.

  17. Life history strategy influences parasite responses to habitat fragmentation.

    PubMed

    Froeschke, Götz; van der Mescht, Luther; McGeoch, Melodie; Matthee, Sonja

    2013-12-01

    Anthropogenic habitat use is a major threat to biodiversity and is known to increase the abundance of generalist host species such as rodents, which are regarded as potential disease carriers. Parasites have an intimate relationship with their host and the surrounding environment and it is expected that habitat fragmentation will affect parasite infestation levels. We investigated the effect of habitat fragmentation on the ecto- and endoparasitic burdens of a broad niche small mammal, Rhabdomys pumilio, in the Western Cape Province, South Africa. Our aim was to look at the effects of fragmentation on different parasite species with diverse life history characteristics and to determine whether general patterns can be found. Sampling took place within pristine lowland (Fynbos/Renosterveld) areas and at fragmented sites surrounded and isolated by agricultural activities. All arthropod ectoparasites and available gastrointestinal endoparasites were identified. We used conditional autoregressive models to investigate the effects of habitat fragmentation on parasite species richness and abundance of all recovered parasites. Host density and body size were larger in the fragments. Combined ecto- as well as combined endoparasite taxa showed higher parasite species richness in fragmented sites. Parasite abundance was generally higher in the case of R. pumilio individuals in fragmented habitats but it appears that parasites that are more permanently associated with the host's body and those that are host-specific show the opposite trend. Parasite life history is an important factor that needs to be considered when predicting the effects of habitat fragmentation on parasite and pathogen transmission. PMID:23954434

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

    PubMed

    Gregory, William F; Maizels, Rick M

    2008-01-01

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

  19. Host-Parasite Interactions from the Inside: Plant Reproductive Ontogeny Drives Specialization in Parasitic Insects

    PubMed Central

    Boivin, Thomas; Gidoin, Cindy; von Aderkas, Patrick; Safrana, Jonathan; Candau, Jean-Noël; Chalon, Alain; Sondo, Marion; El Maâtaoui, Mohamed

    2015-01-01

    Host plant interactions are likely key drivers of evolutionary processes involved in the diversification of phytophagous insects. Granivory has received substantial attention for its crucial role in shaping the interaction between plants and their seed parasites, but fine-scale mechanisms explaining the role of host plant reproductive biology on specialization of seed parasites remain poorly described. In a comparative approach using plant histological techniques, we tested the hypotheses that different seed parasite species synchronize their life cycles to specific stages in seed development, and that the stage they target depends on major differences in seed development programs. In a pinaceous system, seed storage products are initiated before ovule fertilization and the wasps target the ovule’s nucellus during megagametogenesis, a stage at which larvae may benefit from the by-products derived from both secreting cells and dying nucellar cells. In a cupressaceous system, oviposition activity peaks later, during embryogenesis, and the wasps target the ovule’s megagametophyte where larvae may benefit from cell disintegration during embryogenesis. Our cytohistological approach shows for the first time how, despite divergent oviposition targets, different parasite species share a common strategy that consists of first competing for nutrients with developing plant structures, and then consuming these developed structures to complete their development. Our results support the prediction that seed developmental program is an axis for specialization in seed parasites, and that it could be an important parameter in models of their ecological and taxonomic divergence. This study provides the basis for further investigating the possibility of the link between plant ontogeny and pre-dispersal seed parasitism. PMID:26441311

  20. Cellular gene expression induced by parasite antigens and allergens in neonates from parasite-infected mothers.

    PubMed

    Soboslay, Peter T; Orlikowsky, Thorsten; Huang, Xiangsheng; Gille, Christian; Spring, Bärbel; Kocherscheidt, Lars; Agossou, Abram; Banla, Meba; Bonin, Michael; Köhler, Carsten

    2016-05-01

    Prenatal exposure to parasite antigens or allergens will influence the profile and strength of postnatal immune responses, such contact may tolerize and increase susceptibility to future infections or sensitize to environmental allergens. Exposure in utero to parasite antigens will distinctly alter cellular gene expression in newborns. Gene microarrays were applied to study gene expression in umbilical cord blood cell (UCBC) from parasite-exposed (Para-POS) and non-exposed (Para-NEG) neonates. UCBC were activated with antigens of helminth (Onchocerca volvulus), amoeba (Entamoeba histolytica) or allergens of mite (Dermatophagoides farinae). When UCBC from Para-POS and Para-NEG newborns were exposed to helminth antigens or allergens consistent differences occurred in the expression of genes encoding for MHC class I and II alleles, signal transducers of activation and transcription (STATs), cytokines, chemokines, immunoglobulin heavy and light chains, and molecules associated with immune regulation (SOCS, TLR, TGF), inflammation (TNF, CCR) and apoptosis (CASP). Expression of genes associated with innate immune responses were enhanced in Para-NEG, while in Para-POS, the expression of MHC class II and STAT genes was reduced. Within functional gene networks for cellular growth, proliferation and immune responses, Para-NEG neonates presented with significantly higher expression values than Para-POS. In Para-NEG newborns, the gene cluster and pathway analyses suggested that gene expression profiles may predispose for the development of immunological, hematological and dermatological disorders upon postnatal helminth parasite infection or allergen exposure. Thus, prenatal parasite contact will sensitize without generating aberrant inflammatory immune responses, and increased pro-inflammatory but decreased regulatory gene expression profiles will be present in those neonates lacking prenatal parasite antigen encounter. PMID:27062712

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

    PubMed Central

    Fenton, Andy; Speed, Michael P.

    2016-01-01

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

  2. How a haemosporidian parasite of bats gets around: the genetic structure of a parasite, vector and host compared.

    PubMed

    Witsenburg, F; Clément, L; López-Baucells, A; Palmeirim, J; Pavlinić, I; Scaravelli, D; Ševčík, M; Dutoit, L; Salamin, N; Goudet, J; Christe, P

    2015-02-01

    Parasite population structure is often thought to be largely shaped by that of its host. In the case of a parasite with a complex life cycle, two host species, each with their own patterns of demography and migration, spread the parasite. However, the population structure of the parasite is predicted to resemble only that of the most vagile host species. In this study, we tested this prediction in the context of a vector-transmitted parasite. We sampled the haemosporidian parasite Polychromophilus melanipherus across its European range, together with its bat fly vector Nycteribia schmidlii and its host, the bent-winged bat Miniopterus schreibersii. Based on microsatellite analyses, the wingless vector, and not the bat host, was identified as the least structured population and should therefore be considered the most vagile host. Genetic distance matrices were compared for all three species based on a mitochondrial DNA fragment. Both host and vector populations followed an isolation-by-distance pattern across the Mediterranean, but not the parasite. Mantel tests found no correlation between the parasite and either the host or vector populations. We therefore found no support for our hypothesis; the parasite population structure matched neither vector nor host. Instead, we propose a model where the parasite's gene flow is represented by the added effects of host and vector dispersal patterns. PMID:25641066

  3. Critical tests with oxibendazole against gastrointestinal parasites of ponies.

    PubMed

    Nawalinski, T; Theodorides, V J

    1976-04-01

    Twenty ponies were allotted to 4 groups of 5 ponies each, and oxibendazole was orally administered at dose levels of 5, 10, 15, and 20 mg/kg. In the 3 groups of ponies given the largest doses, efficacy against 3 species of Strongylus was between 92 and 100% and that against small strongylids of the genera Cyathostomum, Cylicocyclus, Cylicodontophorus, and Cylicostephanus was more than 99%. All adults and 95 to 100% of larvae of the pinworm Oxyuris equi were removed. In the group of ponies given 5 mg/kg, 86 to 100% of the large strongylids and 84 to 100% of the small strongylids were removed, as were all larval and adult pinworms. Trichostrongylus axei was found only in 4 of the 5 ponies given 5 mg/kg; results were encouraging, but not consistent. Almost all of the Parascaris equorum were found in this group of ponies; no anthelmintic activity was detected at this dose level. Oxibendazole removed approximately 99% of small strongylid 4th-stage larvae. No efficacy against the larval stages of Gasterophilus intestinalis and against Habronema spp and Setaria equina was observed. PMID:1267243

  4. Study on parasites from farm animals in Kuwait.

    PubMed

    Majeed, Qais A H; Alazemi, Maha S; Henedi, Adawia A M; Tahrani, Laila M A

    2015-04-01

    No doubt, farm animals are essential as a source of milk, protein, and leather and wool ... etc. But, they are always exposed to ecto- and endo-parasites, which cause diseases conditions that may end in death. This study evaluated farm animal parasitosis. Thus, different animal farms were visited to collect fecal samples and data to determine the infection rates with parasites and the relationship between animal management and parasitism in Kuwait. Out of 86, 17, 20, 96 & 52 cattle, sheep, goats, horses and camels examined, 5.5, 17.5, 10, 9.3 and 2.5% respectively were infected with different parasites. These parasites were Ascarids in cattle and horses, Strongylids in cattle, horses and camels, and Eimeriids in cattle and small ruminants. Eimeria spp. were the most prevalent parasite particularly in small ruminants. The relationship between Eimeria infection and management in small ruminant farms was discussed. PMID:26012220

  5. Highly rearranged mitochondrial genome in Nycteria parasites (Haemosporidia) from bats.

    PubMed

    Karadjian, Gregory; Hassanin, Alexandre; Saintpierre, Benjamin; Gembu Tungaluna, Guy-Crispin; Ariey, Frederic; Ayala, Francisco J; Landau, Irene; Duval, Linda

    2016-08-30

    Haemosporidia parasites have mostly and abundantly been described using mitochondrial genes, and in particular cytochrome b (cytb). Failure to amplify the mitochondrial cytb gene of Nycteria parasites isolated from Nycteridae bats has been recently reported. Bats are hosts to a diverse and profuse array of Haemosporidia parasites that remain largely unstudied. There is a need to obtain more molecular data from chiropteran parasites. Such data would help to better understand the evolutionary history of Haemosporidia, which notably include the Plasmodium parasites, malaria's agents. We use next-generation sequencing to obtain the complete mitochondrial genome of Nycteria parasites from African Nycteris grandis (Nycteridae) and Rhinolophus alcyone (Rhinolophidae) and Asian Megaderma spasma (Megadermatidae). We report four complete mitochondrial genomes, including two rearranged mitochondrial genomes within Haemosporidia. Our results open outlooks into potentially undiscovered Haemosporidian diversity. PMID:27528689

  6. Using metabolomics to dissect host-parasite interactions.

    PubMed

    Kloehn, J; Blume, M; Cobbold, S A; Saunders, E C; Dagley, M J; McConville, M J

    2016-08-01

    Protozoan parasites have evolved diverse growth and metabolic strategies for surviving and proliferating within different extracellular and intracellular niches in their mammalian hosts. Metabolomic approaches, including high coverage metabolite profiling and (13)C/(2)H-stable isotope labeling, are increasingly being used to identify parasite metabolic pathways that are important for survival and replication in vivo. These approaches are highlighting new links between parasite carbon metabolism and the ability of different parasite stages to colonize specific niches or host cell types. They have also revealed novel metabolic regulatory mechanisms that are important for homeostasis and survival in potentially nutrient variable environments. These studies highlight the importance of parasite and host metabolism as determinants of host-parasite interactions. PMID:27200489

  7. The Haustorium, a Specialized Invasive Organ in Parasitic Plants.

    PubMed

    Yoshida, Satoko; Cui, Songkui; Ichihashi, Yasunori; Shirasu, Ken

    2016-04-29

    Parasitic plants thrive by infecting other plants. Flowering plants evolved parasitism independently at least 12 times, in all cases developing a unique multicellular organ called the haustorium that forms upon detection of haustorium-inducing factors derived from the host plant. This organ penetrates into the host stem or root and connects to its vasculature, allowing exchange of materials such as water, nutrients, proteins, nucleotides, pathogens, and retrotransposons between the host and the parasite. In this review, we focus on the formation and function of the haustorium in parasitic plants, with a specific emphasis on recent advances in molecular studies of root parasites in the Orobanchaceae and stem parasites in the Convolvulaceae. PMID:27128469

  8. Parasite-mediated reduction in fecundity of mountain hares.

    PubMed Central

    Newey, Scott; Thirgood, Simon

    2004-01-01

    Mountain hare populations in Scotland exhibit regular 10 year fluctuations in abundance. Simple models of host-parasite population dynamics suggest that parasite-mediated reductions in host fecundity can cause a transition from stable to cyclic host population dynamics. We tested the hypothesis that parasites reduce hare fecundity by experimentally reducing parasite burdens and recording female survival, body condition and fecundity. We captured 41 adult female hares in October 2002; 22 were treated with Ivermectin to remove parasites and 19 were left untreated as controls. The treated and untreated hares were culled in May 2003 together with a second control group of nine unhandled hares. Treatment with Ivermectin significantly reduced the abundance of Trichostrongylus retortaeformis and increased-the fecundity of the hares, but had no measurable effect on body condition or over-winter survival. These results are consistent with the hypothesis that parasites may be a contributory cause of cycles in populations of mountain hares. PMID:15801590

  9. Plastic behaviors in hosts promote the emergence of retaliatory parasites

    PubMed Central

    Chakra, Maria Abou; Hilbe, Christian; Traulsen, Arne

    2014-01-01

    Mafia like behavior, where individuals cooperate under the threat of punishment, occurs not only in humans, but is also observed in several animal species. Observations suggest that avian hosts tend to accept a certain degree of parasitism in order to avoid retaliating punishment from the brood parasite. To understand under which conditions it will be beneficial for a host to cooperate, we model the interaction between hosts and parasites as an evolutionary game. In our model, the host's behavior is plastic, and thus, its response depends on the previous interactions with the parasite. We find that such learned behavior in turn is crucial for the evolution of retaliating parasites. The abundance of this kind of mafia behavior oscillates in time and does not settle to an equilibrium. Our results suggest that retaliation is a mechanism for the parasite to evade specialization and to induce acceptance by the host. PMID:24589512

  10. Orthologs of macrophage migration inhibitory factor from parasitic nematodes

    PubMed Central

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

    2013-01-01

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

  11. Plastic behaviors in hosts promote the emergence of retaliatory parasites.

    PubMed

    Abou Chakra, Maria; Hilbe, Christian; Traulsen, Arne

    2014-01-01

    Mafia like behavior, where individuals cooperate under the threat of punishment, occurs not only in humans, but is also observed in several animal species. Observations suggest that avian hosts tend to accept a certain degree of parasitism in order to avoid retaliating punishment from the brood parasite. To understand under which conditions it will be beneficial for a host to cooperate, we model the interaction between hosts and parasites as an evolutionary game. In our model, the host's behavior is plastic, and thus, its response depends on the previous interactions with the parasite. We find that such learned behavior in turn is crucial for the evolution of retaliating parasites. The abundance of this kind of mafia behavior oscillates in time and does not settle to an equilibrium. Our results suggest that retaliation is a mechanism for the parasite to evade specialization and to induce acceptance by the host. PMID:24589512

  12. Carotenoid-based bill colour is an integrative signal of multiple parasite infection in blackbird

    NASA Astrophysics Data System (ADS)

    Biard, Clotilde; Saulnier, Nicolas; Gaillard, Maria; Moreau, Jérôme

    2010-11-01

    In the study of parasite-mediated sexual selection, there has been controversial evidence for the prediction that brighter males should have fewer parasites. Most of these studies have focused on one parasite species. Our aim was to investigate the expression of carotenoid-based coloured signals in relation to patterns of multiple parasite infections, to determine whether colour reflects parasite load of all parasite species, or whether different relationships might be found when looking at each parasite species independently. We investigated the relationship between bill colour, body mass and plasma carotenoids and parasite load (feather chewing lice, blood parasite Plasmodium sp., intestinal parasites cestodes and coccidia) in the blackbird ( Turdus merula). Bill colour on its own appeared to be a poor predictor of parasite load when investigating its relationships with individual parasite species. Variation in parasite intensities at the community level was summarised using principal component analysis to derive synthetic indexes of relative parasite species abundance and absolute parasite load. The relative abundance of parasite species was strongly related to bill colour, plasma carotenoid levels and body mass: birds with relatively more cestodes and chewing lice and relatively less Plasmodium and coccidia had a more colourful bill, circulated more carotenoids and were heavier. These results suggest that bill colour more accurately reflects the relative intensities of parasite infection, rather than one-by-one relationships with parasites or absolute parasite burden. Investigating patterns of multiple parasite infection would thus improve our understanding of the information conveyed by coloured signals on parasite load.

  13. Protein S-Glutathionylation in Malaria Parasites

    PubMed Central

    Kehr, Sebastian; Jortzik, Esther; Delahunty, Claire; Yates, John R.; Rahlfs, Stefan

    2011-01-01

    Abstract Aims: Protein S-glutathionylation is a widely distributed post-translational modification of thiol groups with glutathione that can function as a redox-sensitive switch to mediate redox regulation and signal transduction. The malaria parasite Plasmodium falciparum is exposed to intense oxidative stress and possesses the enzymatic system required to regulate protein S-glutathionylation, but despite its potential importance, protein S-glutathionylation has not yet been studied in malaria parasites. In this work we applied a method based on enzymatic deglutathionylation, affinity purification of biotin-maleimide-tagged proteins, and proteomic analyses to characterize the Plasmodium glutathionylome. Results: We identified 493 targets of protein S-glutathionylation in Plasmodium. Functional profiles revealed that the targets are components of central metabolic pathways, such as nitrogen compound metabolism and protein metabolism. Fifteen identified proteins with important functions in metabolic pathways (thioredoxin reductase, thioredoxin, thioredoxin peroxidase 1, glutathione reductase, glutathione S-transferase, plasmoredoxin, mitochondrial dihydrolipoamide dehydrogenase, glutamate dehydrogenase 1, glyoxalase I and II, ornithine δ-aminotransferase, lactate dehydrogenase, glyceraldehyde 3-phosphate dehydrogenase [GAPDH], pyruvate kinase [PK], and phosphoglycerate mutase) were further analyzed to study their ability to form mixed disulfides with glutathione. We demonstrate that P. falciparum GAPDH, PK, and ornithine δ-aminotransferase are reversibly inhibited by S-glutathionylation. Further, we provide evidence that not only P. falciparum glutaredoxin 1, but also thioredoxin 1 and plasmoredoxin are able to efficiently catalyze protein deglutathionylation. Innovation: We used an affinity-purification based proteomic approach to characterize the Plasmodium glutathionylome. Conclusion: Our results indicate a wide regulative use of S-glutathionylation in the

  14. Trans-specific gene silencing between host and parasitic plants.

    PubMed

    Tomilov, Alexey A; Tomilova, Natalia B; Wroblewski, Tadeusz; Michelmore, Richard; Yoder, John I

    2008-11-01

    Species of Orobanchaceae parasitize the roots of nearby host plants to rob them of water and other nutrients. Parasitism can be debilitating to the host plant, and some of the world's most pernicious agricultural pests are parasitic weeds. We demonstrate here that interfering hairpin constructs transformed into host plants can silence expression of the targeted genes in the parasite. Transgenic roots of the hemi-parasitic plant Triphysaria versicolor expressing the GUS reporter gene were allowed to parasitize transgenic lettuce roots expressing a hairpin RNA containing a fragment of the GUS gene (hpGUS). When stained for GUS activity, Triphysaria roots attached to non-transgenic lettuce showed full GUS activity, but those parasitizing transgenic hpGUS lettuce lacked activity in root tissues distal to the haustorium. Transcript quantification indicated a reduction in the steady-state level of GUS mRNA in Triphysaria when they were attached to hpGUS lettuce. These results demonstrate that the GUS silencing signal generated by the host roots was translocated across the haustorium interface and was functional in the parasite. Movement across the haustorium was bi-directional, as demonstrated in double-junction experiments in which non-transgenic Triphysaria concomitantly parasitized two hosts, one transgenic for hpGUS and the other transgenic for a functional GUS gene. Observation of GUS silencing in the second host demonstrated that the silencing trigger could be moved from one host to another using the parasite as a physiological bridge. Silencing of parasite genes by generating siRNAs in the host provides a novel strategy for controlling parasitic weeds. PMID:18643992

  15. Parasites of fish larvae: do they follow metabolic energetic laws?

    PubMed

    Muñoz, Gabriela; Landaeta, Mauricio F; Palacios-Fuentes, Pamela; George-Nascimento, Mario

    2015-11-01

    Eumetazoan parasites in fish larvae normally exhibit large body sizes relative to their hosts. This observation raises a question about the potential effects that parasites might have on small fish. We indirectly evaluated this question using energetic metabolic laws based on body volume and the parasite densities. We compared the biovolume as well as the numeric and volumetric densities of parasites over the host body volume of larval and juvenile-adult fish and the average of these parasitological descriptors for castrator parasites and the parasites found in the fish studied here. We collected 5266 fish larvae using nearshore zooplankton sampling and 1556 juveniles and adult fish from intertidal rocky pools in central Chile. We considered only the parasitized hosts: 482 fish larvae and 629 juvenile-adult fish. We obtained 31 fish species; 14 species were in both plankton and intertidal zones. Fish larvae exhibited a significantly smaller biovolume but larger numeric and volumetric densities of parasites than juvenile-adult fish. Therefore, fish larvae showed a large proportion of parasite biovolume per unit of body host (cm(3)). However, the general scaling of parasitological descriptors and host body volume were similar between larvae and juvenile-adult fish. The ratio between the biovolume of parasites and the host body volume in fish larvae was similar to the proportion observed in castrator parasites. Furthermore, the ratios were different from those of juvenile-adult fish, which suggests that the presence of parasites implies a high energetic cost for fish larvae that would diminish the fitness of these small hosts. PMID:26193824

  16. Neurologic Parasitic Infections in Immigrants and Travelers

    PubMed Central

    Thakur, Kiran; Zunt, Joseph

    2012-01-01

    Infectious diseases are increasingly common in modern clinical practice and the contemporary neurologist must be aware of the clinical manifestations, potential complications, and management of common travel-related infections. The authors provide an approach to patients who present with neurologic symptoms, with a history of travel to or residence in tropical and developing countries. Although many other infections are important in this demographic, they focus on three parasitic infections that neurologists may encounter: cerebral malaria, neuroschistosomiasis, and neurocysticercosis. The epidemiology, pathophysiology, clinical manifestations, diagnostic evaluation, and treatment are discussed for each infection. PMID:21964842

  17. Serial Dissection of Parasite Gene Families.

    PubMed

    Bzik, David J

    2016-05-01

    Calcium ion signaling regulates central aspects of the biology controlling stage and life cycle transitions of apicomplexan parasites. In the current issue of Infection and Immunity, Long and coworkers (S. Long, Q. Wang, and L. D. Sibley, Infect Immun 84:1262-1273, 2016, http://dx.doi.org/10.1128/IAI.01173-15) describe a powerful genetic system enabling reliable serial genetic dissection of a large gene family encoding novel calcium-dependent protein kinases (CDPKs) that provides new insights into the roles of CDPKs during Toxoplasma gondii infection. PMID:26953326

  18. Microsporidian parasites feminise hosts without paramyxean co-infection: support for convergent evolution of parasitic feminisation.

    PubMed

    Ironside, Joseph Edward; Alexander, Jenna

    2015-05-01

    Feminisation of amphipod crustaceans is associated with the presence of at least three microsporidian parasites and one paramyxean parasite, suggesting that the ability to feminise has evolved multiple times in parasites of amphipods. Co-infection by a paramyxean with one of the putative microsporidian feminisers, Dictyocoela duebenum, has inspired the alternative hypothesis that all feminisation of amphipods is caused by paramyxea and that all microsporidian associations with feminisation are due to co-infection with paramyxea (Short et al., 2012). In a population of the amphipod Gammarus duebeni, breeding experiments demonstrate that the microsporidia D. duebenum and Nosema granulosis are associated with feminisation in the absence of paramyxea. Co-infection of the two microsporidia is no more frequent than expected at random and each parasite is associated with feminisation in the absence of the other. These findings support the original hypothesis that the ability to feminise amphipods has evolved in microsporidia on multiple occasions. Additionally, the occurrence of a non-feminising strain of D. duebenum in Gammarus pulex suggests that different strains vary in their feminising ability, even within microsporidian species. The presence or absence of feminising ability in a particular microsporidian strain should not therefore be generalised to the species as a whole. PMID:25747725

  19. Checklist of the helminth parasites of South American bats.

    PubMed

    Santos, Cláudia Portes; Gibson, David I

    2015-01-01

    Although the Chiroptera represents a significant proportion (c.20%) of the mammalian fauna and South America has the highest diversity of bat species, only about a third of the known species in this region have had helminth parasites reported from them. This work represents the first comprehensive checklist of the helminth parasites (nematodes, acanthocephalans, trematodes and cestodes) of South American bats. The data were extracted from more than 120 references and are presented as a key to each group of parasites down to the generic level, with an indication of how the bats become infected, accompanied by a list of the species recorded for each genus. This is followed, in tabular form, by parasite-host and host-parasite checklists. The parasite-host list also includes their geographical distribution in South America (at the country level) and site data, plus the references in which the parasite records occur. The host-parasite list is arranged according to the classification of the hosts. In all, c.370 host-parasite associations are recorded, involving 114 nominal species of helminths from 92 named chiropteran taxa. PMID:25947481

  20. Parasites and genetic diversity in an invasive bumblebee

    PubMed Central

    Jones, Catherine M; Brown, Mark J F; Ings, Thomas

    2014-01-01

    Biological invasions are facilitated by the global transportation of species and climate change. Given that invasions may cause ecological and economic damage and pose a major threat to biodiversity, understanding the mechanisms behind invasion success is essential. Both the release of non-native populations from natural enemies, such as parasites, and the genetic diversity of these populations may play key roles in their invasion success. We investigated the roles of parasite communities, through enemy release and parasite acquisition, and genetic diversity in the invasion success of the non-native bumblebee, Bombus hypnorum, in the United Kingdom. The invasive B. hypnorum had higher parasite prevalence than most, or all native congeners for two high-impact parasites, probably due to higher susceptibility and parasite acquisition. Consequently parasites had a higher impact on B. hypnorum queens’ survival and colony-founding success than on native species. Bombus hypnorum also had lower functional genetic diversity at the sex-determining locus than native species. Higher parasite prevalence and lower genetic diversity have not prevented the rapid invasion of the United Kingdom by B. hypnorum. These data may inform our understanding of similar invasions by commercial bumblebees around the world. This study suggests that concerns about parasite impacts on the small founding populations common to re-introduction and translocation programs may be less important than currently believed. PMID:24749545

  1. The immunology of parasite infections in immunocompromised hosts

    PubMed Central

    Evering, T.; Weiss, L. M.

    2011-01-01

    Summary Immune compromise can modify the severity and manifestation of some parasitic infections. More widespread use of newer immnosuppressive therapies, the growing population of individuals with immunocompromised states as well as the prolonged survival of these patients have altered the pattern of parasitic infection. This review article discusses the burden and immunology of parasitic infections in patients who are immunocompromised secondary to congenital immunodeficiency, malnutrition, malignancy, and immunosuppressive medications. This review does not address the literature on parasitic infections in the setting of HIV-1 infection. PMID:17042927

  2. The Neurotropic Parasite Toxoplasma Gondii Increases Dopamine Metabolism

    PubMed Central

    Prandovszky, Emese; Gaskell, Elizabeth; Martin, Heather; Dubey, J. P.; Webster, Joanne P.; McConkey, Glenn A.

    2011-01-01

    The highly prevalent parasite Toxoplasma gondii manipulates its host's behavior. In infected rodents, the behavioral changes increase the likelihood that the parasite will be transmitted back to its definitive cat host, an essential step in completion of the parasite's life cycle. The mechanism(s) responsible for behavioral changes in the host is unknown but two lines of published evidence suggest that the parasite alters neurotransmitter signal transduction: the disruption of the parasite-induced behavioral changes with medications used to treat psychiatric disease (specifically dopamine antagonists) and identification of a tyrosine hydroxylase encoded in the parasite genome. In this study, infection of mammalian dopaminergic cells with T. gondii enhanced the levels of K+-induced release of dopamine several-fold, with a direct correlation between the number of infected cells and the quantity of dopamine released. Immunostaining brain sections of infected mice with dopamine antibody showed intense staining of encysted parasites. Based on these analyses, T. gondii orchestrates a significant increase in dopamine metabolism in neural cells. Tyrosine hydroxylase, the rate-limiting enzyme for dopamine synthesis, was also found in intracellular tissue cysts in brain tissue with antibodies specific for the parasite-encoded tyrosine hydroxylase. These observations provide a mechanism for parasite-induced behavioral changes. The observed effects on dopamine metabolism could also be relevant in interpreting reports of psychobehavioral changes in toxoplasmosis-infected humans. PMID:21957440

  3. [Parasites as a natural element of any ecosystem].

    PubMed

    Pojmańska, Teresa

    2002-01-01

    The article presents some ideas upon the functioning of the parasite populations and communities in relation to the whole ecosystem. The author underlines that the parasites are one of the natural elements of every biocenosis and their existence submittes to similar ecological rules as the populations and communities of free-living organisms. Colonization of their particular environment (living organism) demands some adaptations allowing to resist immunological defense of the host, and to coexist with other parasite species harboured by the same host, not exploiting the supplies over the host "carying capacity", what could provoke the strong pathogenic effects, including host death. The mechanims maintaning the state of relative stability in host-parasite system are similar as in the case of free-living organisms, and are of both parasite- and host origin. They can confine the number of parasites (elimination of some specimens) or their biomass (growth restraint), limit their fecundity (maturation restraint), or make particular species to use different supply (niches separation). On the other hand parasite can regulate the demography of host population: restrict their fecundity, or kill their host directly or indirectly (making them an easier prey for predators). The author presents and discusses some examples illustrating the activity of the regulating mechanisms in host-parasite relationship, as well as the role of parasites in energetic ballance of ecosystem and in "engineering of ecosystem". PMID:16888938

  4. Myco-Heterophytes and Parasitic Plants in Food Chains.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1999-01-01

    Advocates including plants at several trophic levels when studying food chains. Presents background information on parasitic plants, myco-heterophytes (saprophytes), and carnivorous plants. Contains 20 references. (WRM)

  5. Parasite host range and the evolution of host resistance.

    PubMed

    Gorter, F A; Hall, A R; Buckling, A; Scanlan, P D

    2015-05-01

    Parasite host range plays a pivotal role in the evolution and ecology of hosts and the emergence of infectious disease. Although the factors that promote host range and the epidemiological consequences of variation in host range are relatively well characterized, the effect of parasite host range on host resistance evolution is less well understood. In this study, we tested the impact of parasite host range on host resistance evolution. To do so, we used the host bacterium Pseudomonas fluorescens SBW25 and a diverse suite of coevolved viral parasites (lytic bacteriophage Φ2) with variable host ranges (defined here as the number of host genotypes that can be infected) as our experimental model organisms. Our results show that resistance evolution to coevolved phages occurred at a much lower rate than to ancestral phage (approximately 50% vs. 100%), but the host range of coevolved phages did not influence the likelihood of resistance evolution. We also show that the host range of both single parasites and populations of parasites does not affect the breadth of the resulting resistance range in a naïve host but that hosts that evolve resistance to single parasites are more likely to resist other (genetically) more closely related parasites as a correlated response. These findings have important implications for our understanding of resistance evolution in natural populations of bacteria and viruses and other host-parasite combinations with similar underlying infection genetics, as well as the development of phage therapy. PMID:25851735

  6. Differential escape from parasites by two competing introduced crabs

    USGS Publications Warehouse

    Blakeslee, April M.; Keogh, Carolyn L.; Byers, James E.; Kuris, Armand M.; Lafferty, Kevin D.; Torchin, Mark E.

    2009-01-01

    Although introduced species often interact with one another in their novel communities, the role of parasites in these interactions remains less clear. We examined parasite richness and prevalence in 2 shorecrab species with different invasion histories and residency times in an introduced region where their distributions overlap broadly. On the northeastern coast of the USA, the Asian shorecrab Hemigrapsus sanguineus was discovered 20 yr ago, while the European green crab Carcinus maenas has been established for over 200 yr. We used literature and field surveys to evaluate parasitism in both crabs in their native and introduced ranges. We found only 1 parasite species infecting H. sanguineus on the US East Coast compared to 6 species in its native range, while C. maenas was host to 3 parasite species on the East Coast compared to 10 in its native range. The prevalence of parasite infection was also lower for both crabs in the introduced range compared to their native ranges; however, the difference was almost twice as much for H. sanguineus as for C. maenas. There are several explanations that could contribute to C. maenas' greater parasite diversity than that of H. sanguineus on the US East Coast, including differences in susceptibility, time since introduction, manner of introduction (vector), distance from native range, taxonomic isolation, and the potential for parasite identification bias. Our study underscores not just that non-native species lose parasites upon introduction, but that they may do so differentially, with ramifications for their direct interactions and with potential community-level influences.

  7. [General overview of camel parasites and the situation in Turkey].

    PubMed

    Azrug, Abdalla Fadlalla; Burgu, Ayşe

    2011-01-01

    The aim of this review is overview the main protozoan, arthropoda and helminthic parasites seen in camels and to evaluate the publications related to camel parasites in Turkey. In different parts of the world, trichostrongylose, mange, nasal myiasis and trypanosomiasis are the most common parasitic diseases found in camels. Hydatic cyst larval stage of E. granulosus is important both economically and in terms of public health. It is also emphasized that the records concerning parasites of the Turkish camel population, which is decreasing significantly, are extremely limited. PMID:21618196

  8. Host plant resistance to parasitic weeds; recent progress and bottlenecks.

    PubMed

    Yoder, John I; Scholes, Julie D

    2010-08-01

    Parasitic witchweeds (Striga spp.) and broomrapes (Orobanche and Phelipanche spp.) directly invade the roots of crop plants connecting to the vascular system and abstracting nutrients and water. As a consequence they cause devastating losses in crop yield. Genetic resistance to parasitic weeds is a highly desirable component of any control strategy. Resistance to parasitic plants can occur at different stages of the parasite lifecycle: before attachment to the host, during penetration of the root or after establishment of vascular connections. New studies are beginning to shed light on the molecular mechanisms and signaling pathways involved in plant-plant resistance. The first resistance gene to Striga, encoding a CC-NBS-LRR Resistance protein (R) has been identified and cloned suggesting that host plants resist attack from parasitic plants using similar surveillance mechanisms as those used against fungal and bacterial pathogens. It is becoming clear that the salicylic acid (SA) signaling pathway plays an important role in resistance to parasitic plants and genes encoding pathogenesis-related (PR) proteins are upregulated in a number of the resistant interactions. New strategies for engineering resistance to parasitic plants are also being explored, including the expression of parasite-specific toxins in host roots and RNAi to silence parasite genes crucial for development. PMID:20627804

  9. Sensing parasites: Proteomic and advanced bio-detection alternatives.

    PubMed

    Sánchez-Ovejero, Carlos; Benito-Lopez, Fernando; Díez, Paula; Casulli, Adriano; Siles-Lucas, Mar; Fuentes, Manuel; Manzano-Román, Raúl

    2016-03-16

    Parasitic diseases have a great impact in human and animal health. The gold standard for the diagnosis of the majority of parasitic infections is still conventional microscopy, which presents important limitations in terms of sensitivity and specificity and commonly requires highly trained technicians. More accurate molecular-based diagnostic tools are needed for the implementation of early detection, effective treatments and massive screenings with high-throughput capacities. In this respect, sensitive and affordable devices could greatly impact on sustainable control programmes which exist against parasitic diseases, especially in low income settings. Proteomics and nanotechnology approaches are valuable tools for sensing pathogens and host alteration signatures within microfluidic detection platforms. These new devices might provide novel solutions to fight parasitic diseases. Newly described specific parasite derived products with immune-modulatory properties have been postulated as the best candidates for the early and accurate detection of parasitic infections as well as for the blockage of parasite development. This review provides the most recent methodological and technological advances with great potential for bio-sensing parasites in their hosts, showing the newest opportunities offered by modern "-omics" and platforms for parasite detection and control. PMID:26773860

  10. Knowing your enemies: seasonal dynamics of host social parasite recognition

    NASA Astrophysics Data System (ADS)

    D'Ettorre, Patrizia; Brunner, Elisabeth; Wenseleers, Tom; Heinze, Jürgen

    2004-12-01

    Despite its evolutionary significance, behavioural flexibility of social response has rarely been investigated in insects. We studied a host social parasite system: the slave-making ant Polyergus rufescens and its host Formica rufibarbis. Free-living host workers from parasitized and from unparasitized areas were compared in their level of aggression against the parasite and alien conspecifics. We expected that a seasonal change would occur in the acceptance threshold of F. rufibarbis workers from a parasitized area towards the parasite, whereas F. rufibarbis workers from an unparasitized area would not show substantial changes connected with the parasite’s peak in activity (raiding and colony-founding season). The results showed a significant adaptive behavioural flexibility of host species workers and are consistent with the acceptance threshold model’s (Reeve 1989) prediction that recognition systems are not fixed but context-dependent. In particular, host workers from the unparasitized area were highly aggressive towards the parasite regardless of the season, whereas host workers from the parasitized area significantly increased their aggression towards the parasite during its raiding and colony-founding season. Being able to detect and possibly kill a Polyergus scout searching for host nests can be an effective strategy for a Formica colony to avoid being raided or usurped by a parasite queen.

  11. Parasites and parasite management practices of organic and conventional dairy herds in Minnesota.

    PubMed

    Sorge, U S; Moon, R D; Stromberg, B E; Schroth, S L; Michels, L; Wolff, L J; Kelton, D F; Heins, B J

    2015-05-01

    The objective of this study was to describe the prevalence and practices used to manage internal helminth parasites and external arthropod parasites on organic and conventional dairy herds in Minnesota. All organic (ORG) dairy herds in Minnesota (n=114) and a convenience sample of conventional herds were invited to participate in the study. Thirty-five ORG herds and 28 conventional herds were visited once in summer and fall of 2012. Conventional dairy herds were split into small conventional (SC,<200 cows) and medium-sized conventional herds (MC, ≥200 cows) so that SC herds were comparable in size to the ORG herds. Dairy managers were surveyed to assess their farm management practices and perceptions about parasites, hygiene scores were recorded for adult stock, and fecal samples were collected from a nominal 20 breeding-age heifers to characterize abundance of internal parasites. Nonparametric tests were used to compare fecal egg counts per gram (FEC) among farms grouped by management systems and practices. Organic farms had more designated pasture and were more likely to use rotational grazing compared with conventional farms, but the stocking densities of animals on pasture were similar among farm types. The overall FEC were very low, and only a few individual ORG heifers had FEC >500 eggs/gram. Samples from heifers on ORG farms had significantly more strongyle-type eggs than those on SC and MC farms (ORG: 6.6±2.1; SC: 0.5±0.3; MC: 0.8±0.7), but egg counts of other types of gastrointestinal parasites did not differ significantly among the 3 herd groups. Fly control measures were applied mainly to milking cows and preweaned calves and were used on 88.6% of ORG herds, 60.0% of SC herds, and 91.7% of MC herds. Approximately half of the producers reported having seen skin conditions suggestive of lice or tail mange in their cattle during the previous winter (ORG: 48.6%, SC: 57.1%, MC: 53.9%). Although most conventional producers reported treating these skin

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

    PubMed Central

    2014-01-01

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

  13. Innate immunomodulation to trypanosomatid parasite infections.

    PubMed

    Dos-Santos, A L A; Carvalho-Kelly, L F; Dick, C F; Meyer-Fernandes, J R

    2016-08-01

    The recognition of invading pathogens by the innate immune system is essential for host protection against human parasites and the initiation of an effective adaptive immune response. Innate immune cells such as macrophages and dendritic cells (DCs) are involved in the first line of defense against protozoan parasites via sensing the invaders through pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs). Activation of macrophages and dendritic cells starts with the interaction between microbial ligands (pathogen-associated molecular patterns - PAMPs) and PRRs, and these activated cells influence the overall immune response. Trypanosomatid PAMPs are sensed by TLRs; for example, TLR2 recognizes alkylacylglycerol and lipophosphoglycan in Trypanosoma cruzi and Leishmania, respectively; TLR2/TLR4 recognize glycoisnositolphospholipids and glycosylphosphatidyl inositol in Trypanosoma species; and TLR9 recognizes genomic DNA in Trypanosoma. TLR signaling includes the recruitment of different adaptor molecules that activate various transcription factors, such as NF-kB, IRF3/7, and MAP kinases, to induce the production of pro-inflammatory cytokines and type I interferons. Moreover, activated macrophages and dendritic cells produce ROS and NOS, which limit pathogen survival, and large amounts of cytokines; additionally, antigen presentation enhances the adaptive immune response. In this review, we highlight the recent findings on PAMP recognition in trypanosomatid infections and the signaling pathways activated by PRRs. PMID:27223816

  14. Immunopathological study of parasitic cholangitis in cetaceans.

    PubMed

    Jaber, J R; Zafra, R; Pérez, J; Suárez-Bonnet, A; González, J F; Carrascosa, C; Andrada, M; Arbelo, M; Fernández, A

    2013-10-01

    This paper describes the immunophenotype of cellular inflammatory infiltrates in chronic cholangitis in six common dolphins (Delphinus delphis), four striped dolphins (Stenella coeruleoalba), three Atlantic spotted dolphins (Stenella frontalis) and one pygmy sperm whale (Kogia Breviceps) found stranded along the coasts of the Canary Islands (Spain). A panel of 5 antibodies previously tested in dolphins (anti-CD3, -IgG, -MHC class II, -S100 protein and -lysozyme) were used. The present work also reports cross reactivity with dolphin antigens of two antibodies not used to date in dolphins (anti-mouse iNOS and anti-mouse Foxp3). The most common type of cholangitis found was chronic granulomatous cholangitis, associated with the presence of the parasite Campula spp., or its eggs in bile ducts. The cellular composition of the hepatic inflammatory infiltrate associated to chronic parasitic cholangitis was closely similar to that found in the cortex of control lymph nodes, including the presence of S100(+) and MHC class II(+) dendritic-like cells in lymphoid follicles and interfollicular areas. Only occasional macrophages expressed iNOS, whereas Foxp3(+) lymphocytes were not found in any of the lesions described in the different types of cholangitis. PMID:23809732

  15. Gastrointestinal parasites of free-range chickens.

    PubMed

    Tomza-Marciniak, Agnieszka; Pilarczyk, Bogumiła; Tobiańska, Berenika; Tarasewicz, Natalia

    2014-01-01

    The aim of the study was to determine the prevalence and intensity of parasitic gastrointestinal infections in free-range chickens from the West Pomerania province. Experimental material for the study was taken from 10 farms. Breeds raised in farms participating in the study included miniature chickens called Polish Lilliputians and Green- legged Partridge. A total of 104 samples of faeces were examined. The Willis-Schlaff flotation method was used to assess the prevalence of infection, and McMaster's method to evaluate the intensity. The presence of gastrointestinal parasites was found in 9 of the 10 farms. Oocysts of the genus Eimeria and eggs of gastrointestinal nematodes Ascaridia galli, Heterakis gallinarum and Trichostrongylus tenuis were isolated from the chicken faeces. Coccidiosis was found to be dominant parasitosis. The prevalence of infections on these farms with protozoa of Eimeria spp. was on average 32.7%, while for nematode species they amounted to 9.6% for Ascaridia galli, 5.7% for Heterakis gallinarum and 12.5% for Trichostrongylus tenuis. The results indicate the need to take preventive measures, designed to eliminate/reduce the risk of parasitoses in poultry from free-range systems. Focus should be placed on the hygiene of the farming conditions. PMID:25706430

  16. Recent advances in understanding apicomplexan parasites.

    PubMed

    Seeber, Frank; Steinfelder, Svenja

    2016-01-01

    Intracellular single-celled parasites belonging to the large phylum Apicomplexa are amongst the most prevalent and morbidity-causing pathogens worldwide. In this review, we highlight a few of the many recent advances in the field that helped to clarify some important aspects of their fascinating biology and interaction with their hosts. Plasmodium falciparum causes malaria, and thus the recent emergence of resistance against the currently used drug combinations based on artemisinin has been of major interest for the scientific community. It resulted in great advances in understanding the resistance mechanisms that can hopefully be translated into altered future drug regimens. Apicomplexa are also experts in host cell manipulation and immune evasion. Toxoplasma gondii and Theileria sp., besides Plasmodium sp., are species that secrete effector molecules into the host cell to reach this aim. The underlying molecular mechanisms for how these proteins are trafficked to the host cytosol ( T. gondii and Plasmodium) and how a secreted protein can immortalize the host cell ( Theileria sp.) have been illuminated recently. Moreover, how such secreted proteins affect the host innate immune responses against T. gondii and the liver stages of Plasmodium has also been unraveled at the genetic and molecular level, leading to unexpected insights. Methodological advances in metabolomics and molecular biology have been instrumental to solving some fundamental puzzles of mitochondrial carbon metabolism in Apicomplexa. Also, for the first time, the generation of stably transfected Cryptosporidium parasites was achieved, which opens up a wide variety of experimental possibilities for this understudied, important apicomplexan pathogen. PMID:27347391

  17. Recent advances in understanding apicomplexan parasites

    PubMed Central

    Seeber, Frank; Steinfelder, Svenja

    2016-01-01

    Intracellular single-celled parasites belonging to the large phylum Apicomplexa are amongst the most prevalent and morbidity-causing pathogens worldwide. In this review, we highlight a few of the many recent advances in the field that helped to clarify some important aspects of their fascinating biology and interaction with their hosts. Plasmodium falciparum causes malaria, and thus the recent emergence of resistance against the currently used drug combinations based on artemisinin has been of major interest for the scientific community. It resulted in great advances in understanding the resistance mechanisms that can hopefully be translated into altered future drug regimens. Apicomplexa are also experts in host cell manipulation and immune evasion. Toxoplasma gondii and Theileria sp., besides Plasmodium sp., are species that secrete effector molecules into the host cell to reach this aim. The underlying molecular mechanisms for how these proteins are trafficked to the host cytosol ( T. gondii and Plasmodium) and how a secreted protein can immortalize the host cell ( Theileria sp.) have been illuminated recently. Moreover, how such secreted proteins affect the host innate immune responses against T. gondii and the liver stages of Plasmodium has also been unraveled at the genetic and molecular level, leading to unexpected insights. Methodological advances in metabolomics and molecular biology have been instrumental to solving some fundamental puzzles of mitochondrial carbon metabolism in Apicomplexa. Also, for the first time, the generation of stably transfected Cryptosporidium parasites was achieved, which opens up a wide variety of experimental possibilities for this understudied, important apicomplexan pathogen. PMID:27347391

  18. Lung parasites of shrews from Pennsylvania.

    PubMed

    Laakkonen, J; Haukisalmi, V; Merritt, J F

    1997-04-01

    We examined lung parasites of three species of soricids, Sorex cinereus (n = 58), Sorex fumeus (n = 23) and Blarina brevicauda (n = 45) collected from Pennsylvania (USA), from 1990 to 1995. Yeast-like cells of Hisfoplasma capsulatum var. capsulatum were found in lung sections stained with Grocott's modification of Gomori's methenamine silver, periodic acid-Schiff, Giemsa, and hematoxylin-eosin in two (3%) S. cinereus, eight (35%) S. fumeus and two (4%) B. brevicauda. The number of spores of H. capsulatum in the lungs was low and no inflammatory reaction was evident. The infection was not disseminated to other organs. This is the first report of H. capsulatum infection in any species of shrews of the genus Sorex and the prevalence in S. fumeus was remarkably high compared to those reported for other wild mammals. A nematode, possibly Angiostrongylus michiganensis, was found in the lungs of one S. fumeus on necropsy and in a stained lung section of one S. cinereus. In both cases the host was also infected with the fungus. Pneumocystis carinii, which is the most common lung parasite in Sorex araneus (the numerically dominant Eurasian species of shrew), was not found in any of the North American species of shrew examined in this study. PMID:9131560

  19. Motility modes of the parasite Trypanosoma brucei

    NASA Astrophysics Data System (ADS)

    Temel, Fatma Zeynep; Qu, Zijie; McAllaster, Michael; de Graffenried, Christopher; Breuer, Kenneth

    2015-11-01

    The parasitic single-celled protozoan Trypanosoma brucei causes African Sleeping Sickness, which is a fatal disease in humans and animals that threatens more than 60 million people in 36 African countries. Cell motility plays a critical role in the developmental phases and dissemination of the parasite. Unlike many other motile cells such as bacteria Escherichia coli or Caulobacter crescentus, the flagellum of T. brucei is attached along the length of its awl-like body, producing a unique mode of motility that is not fully understood or characterized. Here, we report on the motility of T. brucei, which swims using its single flagellum employing both rotating and undulating propulsion modes. We tracked cells in real-time in three dimensions using fluorescent microscopy. Data obtained from experiments using both short-term tracking within the field of view and long-term tracking using a tracking microscope were analyzed. Motility modes and swimming speed were analyzed as functions of cell size, rotation rate and undulation pattern. Research supported by NSF.

  20. Inflammasomes in host response to protozoan parasites.

    PubMed

    Zamboni, Dario S; Lima-Junior, Djalma S

    2015-05-01

    Inflammasomes are multimeric complexes of proteins that are assembled in the host cell cytoplasm in response to specific stress signals or contamination of the cytoplasm by microbial molecules. The canonical inflammasomes are composed of at least three main components: an inflammatory caspase (caspase-1, caspase-11), an adapter molecule (such as ASC), and a sensor protein (such as NLRP1, NLRP3, NLRP12, NAIP1, NAIP2, NAIP5, or AIM2). The sensor molecule determines the inflammasome specificity by detecting specific microbial products or cell stress signals. Upon activation, these molecular platforms facilitate restriction of microbial replication and trigger an inflammatory form of cell death called pyroptosis, thus accounting for the genesis of inflammatory processes. Inflammasome activation has been widely reported in response to pathogenic bacteria. However, recent reports have highlighted the important role of the inflammasomes in the host response to the pathogenesis of infections caused by intracellular protozoan parasites. Herein, we review the activation and specific roles of inflammasomes in recognition and host responses to intracellular protozoan parasites such as Trypanosoma cruzi, Toxoplasma gondii, Plasmodium spp., and Leishmania spp. PMID:25879291

  1. Pellicle formation in the malaria parasite

    PubMed Central

    Kono, Maya; Heincke, Dorothee; Wilcke, Louisa; Wong, Tatianna Wai Ying; Bruns, Caroline; Herrmann, Susann; Spielmann, Tobias; Gilberger, Tim W.

    2016-01-01

    ABSTRACT The intraerythrocytic developmental cycle of Plasmodium falciparum is completed with the release of up to 32 invasive daughter cells, the merozoites, into the blood stream. Before release, the final step of merozoite development is the assembly of the cortical pellicle, a multi-layered membrane structure. This unique apicomplexan feature includes the inner membrane complex (IMC) and the parasite's plasma membrane. A dynamic ring structure, referred to as the basal complex, is part of the IMC and helps to divide organelles and abscises in the maturing daughter cells. Here, we analyze the dynamics of the basal complex of P. falciparum. We report on a novel transmembrane protein of the basal complex termed BTP1, which is specific to the genus Plasmodium. It colocalizes with the known basal complex marker protein MORN1 and shows distinct dynamics as well as localization when compared to other IMC proteins during schizogony. Using a parasite plasma membrane marker cell line, we correlate dynamics of the basal complex with the acquisition of the maternal membrane. We show that plasma membrane invagination and IMC propagation are interlinked during the final steps of cell division. PMID:26763910

  2. Pellicle formation in the malaria parasite.

    PubMed

    Kono, Maya; Heincke, Dorothee; Wilcke, Louisa; Wong, Tatianna Wai Ying; Bruns, Caroline; Herrmann, Susann; Spielmann, Tobias; Gilberger, Tim W

    2016-02-15

    The intraerythrocytic developmental cycle of Plasmodium falciparum is completed with the release of up to 32 invasive daughter cells, the merozoites, into the blood stream. Before release, the final step of merozoite development is the assembly of the cortical pellicle, a multi-layered membrane structure. This unique apicomplexan feature includes the inner membrane complex (IMC) and the parasite's plasma membrane. A dynamic ring structure, referred to as the basal complex, is part of the IMC and helps to divide organelles and abscises in the maturing daughter cells. Here, we analyze the dynamics of the basal complex of P. falciparum. We report on a novel transmembrane protein of the basal complex termed BTP1, which is specific to the genus Plasmodium. It colocalizes with the known basal complex marker protein MORN1 and shows distinct dynamics as well as localization when compared to other IMC proteins during schizogony. Using a parasite plasma membrane marker cell line, we correlate dynamics of the basal complex with the acquisition of the maternal membrane. We show that plasma membrane invagination and IMC propagation are interlinked during the final steps of cell division. PMID:26763910

  3. Phylogeny, host-parasite relationship and zoogeography

    PubMed Central

    1999-01-01

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

  4. The distinct proteome of placental malaria parasites.

    SciTech Connect

    Fried, Michal; Hixson, Kim K.; Anderson, Lori; Ogata, Yuko; Mutabingwa, Theonest K.; Duffy, Patrick E.

    2007-09-01

    Malaria proteins expressed on the surface of Plasmodium falciparum infected erythrocytes (IE) mediate adhesion and are targeted by protective immune responses. During pregnancy, IE sequester in the placenta. Placental IE bind to the molecule chondroitin sulfate A (CSA) and preferentially transcribe the gene that encodes VAR2CSA, a member of the PfEMP1 variant surface antigen family. Over successive pregnancies women develop specific immunity to CSA-binding IE and antibodies to VAR2CSA. We used tandem mass spectrometry together with accurate mass and time tag technology to study IE membrane fractions of placental parasites. VAR2CSA peptides were detected in placental IE and in IE from children, but the MC variant of VAR2CSA was specifically associated with placental IE. We identified six conserved hypothetical proteins with putative TM or signal peptides that were exclusively expressed by the placental IE, and 11 such proteins that were significantly more abundant in placental IE. One of these hypothetical proteins, PFI1785w, is a 42kDa molecule detected by Western blot in parasites infecting pregnant women but not those infecting children.

  5. Parasite prevalence corresponds to host life history in a diverse assemblage of afrotropical birds and haemosporidian parasites.

    PubMed

    Lutz, Holly L; Hochachka, Wesley M; Engel, Joshua I; Bell, Jeffrey A; Tkach, Vasyl V; Bates, John M; Hackett, Shannon J; Weckstein, Jason D

    2015-01-01

    Avian host life history traits have been hypothesized to predict rates of infection by haemosporidian parasites. Using molecular techniques, we tested this hypothesis for parasites from three haemosporidian genera (Plasmodium, Haemoproteus, and Leucocytozoon) collected from a diverse sampling of birds in northern Malawi. We found that host life history traits were significantly associated with parasitism rates by all three parasite genera. Nest type and nest location predicted infection probability for all three parasite genera, whereas flocking behavior is an important predictor of Plasmodium and Haemoproteus infection and habitat is an important predictor of Leucocytozoon infection. Parasite prevalence was 79.1% across all individuals sampled, higher than that reported for comparable studies from any other region of the world. Parasite diversity was also exceptionally high, with 248 parasite cytochrome b lineages identified from 152 host species. A large proportion of Plasmodium, Haemoproteus, and Leucocytozoon parasite DNA sequences identified in this study represent new, previously undocumented lineages (n = 201; 81% of total identified) based on BLAST queries against the avian malaria database, MalAvi. PMID:25853491

  6. Prevalence of parasitism and adult survival time of Aedes albifasciatus (Diptera: Culicidae) parasitized by Strelkovimermis spiculatus (Nematoda: Mermithidae).

    PubMed

    Di Battista, Cristian M; Fischer, Sylvia; Campos, Raúl E

    2015-12-01

    We described the carryover of Strelkovimermis spiculatus (Poinar and Camino) (Nematoda: Mermithidae) from mosquito larvae, the primary site of maturation, to adults. We analyzed the survival time of male and female Aedes albifasciatus (Macquart) (Diptera: Culicidae) parasitized by S. spiculatus, the time of emergence of nematodes from adult mosquitoes, and the state of parasitism in the same mosquito cohorts during the immature stages. Mosquito larvae with single and multiple parasitism (up to 11 parasites) were observed. The mortality of mosquito larvae and adults was produced in all cases where at least one mermithid emerged. The mortality of S. spiculatus showed an increasing trend in mosquito larvae with larger numbers of nematodes and was higher in larvae parasitized by eight or more nematodes. Maximum survival of parasitized adult females of Ae. albifasciatus was 38 days, while non-parasitized adult males and females survived 39 and 41 days, respectively. Strelkovimermis spiculatus mortality was observed in Ae. albifasciatus larvae with single or multiple parasitisms. The spread of mermithid parasitism in adult mosquito populations is discussed. PMID:26611976

  7. Host-parasite relationships as determinants of heavy metal concentrations in perch (Perca fluviatilis) and its intestinal parasite infection.

    PubMed

    Brázová, Tímea; Hanzelová, Vladimíra; Miklisová, Dana; Šalamún, Peter; Vidal-Martínez, Víctor M

    2015-12-01

    The concentrations of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn and their bioconcentration factors (BCFs) were determined in two intestinal parasites, an acanthocephalan, Acanthocephalus lucii, a tapeworm, Proteocephalus percae, present in the same host, the European perch (Perca fluviatilis, L.), in the heavily polluted Ružín reservoir in eastern Slovakia. The bioaccumulation of heavy metals in the fish organs and parasites was studied for acanthocephalan and tapeworm monoinfections or mixed infections by the two parasites and for the size of their parasitic infrapopulations. Bioconcentration factors (c[parasite]/c[muscle tissue]) showed that the concentrations of As, Ni, Pb and Zn were higher in mixed infections than in monoinfections. Negative correlations between heavy metal concentrations in perch organs and the parasites were found. For example, higher concentrations of Ni and Zn in both parasite species corresponded with lower metal concentrations in perch and hard roe. Likewise, significant negative relationships between metal concentrations in fish organs and number of parasites were noticed with lower levels of Pb in fish harbouring higher numbers of tapeworms. Similarly, in both parasite species the concentrations of some essential elements (Cr, Mn) were lower at high infection intensities compared to low intensities. Our study revealed that the differential concentration of heavy metals in perch organs was affected by the type of infection (mono- or mixed-infection), and needs to be considered in field ecotoxicological and parasitological studies as a potentially important factor influencing the pollutant concentrations in fish. PMID:26432028

  8. Parasite Prevalence Corresponds to Host Life History in a Diverse Assemblage of Afrotropical Birds and Haemosporidian Parasites

    PubMed Central

    Lutz, Holly L.; Hochachka, Wesley M.; Engel, Joshua I.; Bell, Jeffrey A.; Tkach, Vasyl V.; Bates, John M.; Hackett, Shannon J.; Weckstein, Jason D.

    2015-01-01

    Avian host life history traits have been hypothesized to predict rates of infection by haemosporidian parasites. Using molecular techniques, we tested this hypothesis for parasites from three haemosporidian genera (Plasmodium, Haemoproteus, and Leucocytozoon) collected from a diverse sampling of birds in northern Malawi. We found that host life history traits were significantly associated with parasitism rates by all three parasite genera. Nest type and nest location predicted infection probability for all three parasite genera, whereas flocking behavior is an important predictor of Plasmodium and Haemoproteus infection and habitat is an important predictor of Leucocytozoon infection. Parasite prevalence was 79.1% across all individuals sampled, higher than that reported for comparable studies from any other region of the world. Parasite diversity was also exceptionally high, with 248 parasite cytochrome b lineages identified from 152 host species. A large proportion of Plasmodium, Haemoproteus, and Leucocytozoon parasite DNA sequences identified in this study represent new, previously undocumented lineages (n = 201; 81% of total identified) based on BLAST queries against the avian malaria database, MalAvi. PMID:25853491

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

    PubMed Central

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

    2009-01-01

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

  10. Parasitism and the evolutionary ecology of animal personality

    PubMed Central

    Barber, Iain; Dingemanse, Niels J.

    2010-01-01

    The ecological factors responsible for the evolution of individual differences in animal personality (consistent individual differences in the same behaviour across time and contexts) are currently the subject of intense debate. A limited number of ecological factors have been investigated to date, with most attention focusing on the roles of resource competition and predation. We suggest here that parasitism may play a potentially important, but largely overlooked, role in the evolution of animal personalities. We identify two major routes by which parasites might influence the evolution of animal personality. First, because the risk of acquiring parasites can be influenced by an individual's behavioural type, local parasite regimes may impose selection on personality traits and behavioural syndromes (correlations between personality traits). Second, because parasite infections have consequences for aspects of host ‘state’, parasites might induce the evolution of individual differences in certain types of host behaviour in populations with endemic infections. Also, because infection often leads to specific changes in axes of personality, parasite infections have the potential to decouple behavioural syndromes. Host–parasite systems therefore provide researchers with valuable tools to study personality variation and behavioural syndromes from a proximate and ultimate perspective. PMID:21078659

  11. The inverse niche model for food webs with parasites

    USGS Publications Warehouse

    Warren, Christopher P.; Pascual, Mercedes; Lafferty, Kevin D.; Kuris, Armand M.

    2010-01-01

    Although parasites represent an important component of ecosystems, few field and theoretical studies have addressed the structure of parasites in food webs. We evaluate the structure of parasitic links in an extensive salt marsh food web, with a new model distinguishing parasitic links from non-parasitic links among free-living species. The proposed model is an extension of the niche model for food web structure, motivated by the potential role of size (and related metabolic rates) in structuring food webs. The proposed extension captures several properties observed in the data, including patterns of clustering and nestedness, better than does a random model. By relaxing specific assumptions, we demonstrate that two essential elements of the proposed model are the similarity of a parasite's hosts and the increasing degree of parasite specialization, along a one-dimensional niche axis. Thus, inverting one of the basic rules of the original model, the one determining consumers' generality appears critical. Our results support the role of size as one of the organizing principles underlying niche space and food web topology. They also strengthen the evidence for the non-random structure of parasitic links in food webs and open the door to addressing questions concerning the consequences and origins of this structure.

  12. Parasitic castration by Xenos vesparum depends on host gender.

    PubMed

    Cappa, Federico; Manfredini, Fabio; Dallai, Romano; Gottardo, Marco; Beani, Laura

    2014-07-01

    Host castration represents a mechanism used by parasites to exploit energy resources from their hosts by interfering with their reproductive development or to extend host lifespan by removing risks associated with reproductive activity. One of the most intriguing groups of parasitic castrators is represented by the insects belonging to the order Strepsiptera. The macroparasite Xenos vesparum can produce dramatic phenotypic alterations in its host, the paper wasp Polistes dominula. Parasitized female wasps have undeveloped ovaries and desert the colony without performing any social task. However, very little attention has been given to the parasitic impact of X. vesparum on the male phenotype. Here, we investigated the effects of this parasite on the sexual behaviour and the morpho-physiology of P. dominula males. We found that, differently from female wasps, parasitized males are not heavily affected by Xenos: they maintain their sexual behaviour and ability to discriminate between female castes. Furthermore, the structure of their reproductive apparatus is not compromised by the parasite. We think that our results, demonstrating that the definition of X. vesparum as a parasitoid does not apply to infected males of P. dominula, provide a new perspective to discuss and maybe reconsider the traditional view of strepsipteran parasites. PMID:24776461

  13. Parasites, immunology of hosts, and host sexual selection.

    PubMed

    Møller, A P; Saino, N

    1994-12-01

    Parasite-mediated sexual selection is reviewed with special emphasis on the bird literature. Choosy females may benefit from choosing parasite-free mates if such males provide better parental care, do not transmit contagious parasites, or provide resistance genes to offspring. There is evidence in support of each of these mechanisms. The immunocompetence handicap hypothesis posits that secondary sexual characters reliably reveal the ability of males to resist parasites due to the immunosuppressive effects of testosterone and other biochemicals. Several aspects of these negative feedback mechanisms are supported by laboratory studies, but evidence from free-living animals is almost completely absent. Corticosterone rather than testosterone may potentially mediate the immunocompetence handicap mechanism. A simple version of the immunocompetence handicap is developed suggesting that body condition of male hosts is a sufficient mediator of the handicap mechanism of reliable sexual signaling. Sexual selection appears to be more intense in sexually dichromatic bird species, and comparative studies using pairwise comparisons of closely related taxa reveal that sexually dichromatic bird species have larger spleens, larger bursa of Fabricius, and higher concentrations of leukocytes than monochromatic species. Parasite-mediated sexual selection is proposed to affect parasite biology by increasing (1) the variance-to-mean ratio in parasite abundance, (2) variance in the intensity of natural selection affecting hosts, and (3) speciation rates among parasites exploiting hosts subject to intense sexual selection as compared to those subject to less intense selection. PMID:7799157

  14. RESTRICTED GENETIC DIVERSITY IN THE UBIQUITOUS CATTLE PARASITE, SARCOCYSTIS CRUZI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although parasites of the genus Sarcocystis may have cycled between bovine herbivores and canine carnivores for tens of millions of years, human beings may have profoundly influenced the ecology and evolution of those parasites prevalent in domesticated dogs and cattle. To preliminarily assess the ...

  15. The transcriptomes of the cattle parasitic nematode Ostertagia ostartagi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ostertagia ostertagi is a gastrointestinal parasitic nematode that affects cattle and leads to a loss of production. In this study, we present the first large-scale genomic survey of O. ostertagi by the analysis of expressed transcripts from three stages of the parasite: third-stage larvae, fourth-s...

  16. Pathogenicity of Plant-Parasitic Nematodes on Blueberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Very little is known about the impacts of plant-parasitic nematodes on commercial production of blueberries (Vaccinium spp.). We conducted field surveys in the Pacific Northwest and Canada, as well as controlled experiments in microplots and in the greenhouse, to understand which plant-parasitic ne...

  17. A brood parasite selects for its own egg traits.

    PubMed

    Spottiswoode, Claire N

    2013-10-23

    Many brood parasitic birds lay eggs that mimic their hosts' eggs in appearance. This typically arises from selection from discriminating hosts that reject eggs which differ from their own. However, selection on parasitic eggs may also arise from parasites themselves, because it should pay a laying parasitic female to detect and destroy another parasitic egg previously laid in the same host nest by a different female. In this study, I experimentally test the source of selection on greater honeyguide (Indicator indicator) egg size and shape, which is correlated with that of its several host species, all of which breed in dark holes. Its commonest host species did not discriminate against experimental eggs that differed from their own in size and shape, but laying female honeyguides preferentially punctured experimental eggs more than host or control eggs. This should improve offspring survival given that multiple parasitism by this species is common, and that honeyguide chicks kill all other nest occupants. Hence, selection on egg size in greater honeyguides parasitizing bee-eaters appears to be imposed not by host defences but by interference competition among parasites themselves. PMID:23966598

  18. Concurrent Infections (Parasitism and Bacterial Disease) in Tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most laboratory disease studies in tilapia to date have focused on a single parasite or a single bacterial pathogen. In intensive tilapia aquaculture, the reality of a single disease agent resulting in death-loss may be small. More likely, multiple disease agents are present (i.e., parasites, bacter...

  19. Does clutch size evolve in response to parasites and immunocompetence?

    USGS Publications Warehouse

    Martin, T.E.; Moller, A.P.; Merino, S.; Clobert, J.

    2001-01-01

    Parasites have been argued to influence clutch size evolution, but past work and theory has largely focused on within-species optimization solutions rather than clearly addressing among-species variation. The effects of parasites on clutch size variation among species can be complex, however, because different parasites can induce age-specific differences in mortality that can cause clutch size to evolve in different directions. We provide a conceptual argument that differences in immunocompetence among species should integrate differences in overall levels of parasite-induced mortality to which a species is exposed. We test this assumption and show that mortality caused by parasites is positively correlated with immunocompetence measured by cell-mediated measures. Under life history theory, clutch size should increase with increased adult mortality and decrease with increased juvenile mortality. Using immunocompetence as a general assay of parasite-induced mortality, we tested these predictions by using data for 25 species. We found that clutch size increased strongly with adult immunocompetence. In contrast, clutch size decreased weakly with increased juvenile immunocompetence. But, immunocompetence of juveniles may be constrained by selection on adults, and, when we controlled for adult immunocompetence, clutch size decreased with juvenile immunocompetence. Thus, immunocompetence seems to reflect evolutionary differences in parasite virulence experienced by species, and differences in age-specific parasite virulence appears to exert opposite selection on clutch size evolution.

  20. Ranging behavior drives parasite richness: A more parsimonious hypothesis.

    PubMed

    Bicca-Marques, Júlio César; Calegaro-Marques, Cláudia

    2016-09-01

    Parasitism is a ubiquitous interspecific interaction that may play an important role in the evolution of hosts and parasites, molding many aspects of their behavior and ecology. Detecting behavioral changes of hosts infected with parasites is not a straightforward task. Extrapolating from individual-level responses to group-level decision-making is still a much more complex challenge. The ranging behavior of hosts that live in social groups is a good example. Many hypotheses of the cause-effect relationship between this behavior and parasite diversity and load have been proposed. For instance, Brockmeyer et al. [2015, Am. J. Primatol. 77:1036-1048] recently suggested that the richness of protozoan parasites influences the daily path length of free-ranging mandrills. We believe that this explanation for the relationship contains several implicit assumptions. Therefore, we offer an alternative, more parsimonious hypothesis in which daily path length is the driver of parasite richness rather than its consequence. Our hypothesis only assumes that ranging farther exposes animals to a richer parasite diversity. We discuss the data required to test these alternative hypotheses and recall empirical evidence and theoretical modeling results supporting or rejecting their assumptions. We also propose a model of the expected outcomes in terms of species richness, load, intensity of infection, and within-group community similarity of non-lethal environmentally transmitted parasites in social animal groups showing distinct patterns of range use. Am. J. Primatol. 78:923-927, 2016. © 2016 Wiley Periodicals, Inc. PMID:27145909

  1. Evolutionary immune response to conserved domains in parasites and aeroallergens.

    PubMed

    Bielory, Brett Phillip; Mainardi, Timothy; Rottem, Menachem

    2013-01-01

    The immune response based on immunoglobulin E (IgE) evolved as a defense against specific parasitic infections. In the absence of active helminthic infections, the immune system has redirected its IgE epitopes toward innocuous environmental antigens. Helminths and aeroallergens have a similar stereotypical IgE response to unique antigens that can not be explained by chance alone. This study was designed to evaluate potential homology between conserved protein domains embedded in parasitic organisms and aeroallergens. Search and retrieval systems for nucleotide and protein sequences (Entrez, BLAST, and National Center for Biotechnology Information) were searched to identify conserved domains between allergens and certain parasites. A total score was developed that correlated positively with homology between compared sequences. Over 2000 domains were examined. We found matches with a high total score (>100) that signified a strong positive correlation between sequences in allergens (n = 30) and parasites (n = 13). Multiple shared conserved domains were identified between parasites and allergens. Parasite-allergen combinations with the most significant homology (greatest total score) were Plasmodium falciparum enolase and Hev b9 (total score, 612), Schistosoma mansoni albumin and Fel d 2 (total score, 991), Ascaris lumbricoides tropomyosin and Ani s3 (total score, 531), and Wuchereria bancrofti trypsin and Blo t3 (138). Homologous conserved domains exist in specific parasites and allergens, consistent with the theory that the human IgE-eosinophil immune response to common allergens is a direct consequence of stimulation by parasitic organisms. PMID:23406942

  2. Tools for managing internal parasites in small ruminants: Sericea Lespedeza

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control of internal parasites, especially of Haemonchus contortus (barber pole worm, stomach worm), is a primary concern for the majority of sheep and goat producers. These parasites have become more difficult to manage because of increasing resistance to nearly all available dewormers. A severe inf...

  3. Parasitism affects vaccine efficacy against Streptococcus iniae in Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tilapia culture worldwide is estimated to be US$ 5 billion and is important to domestic and global food security. Parasites and bacteria co-occur in both extensive and intensive production of tilapia. The effect of parasitism on vaccine performance in fish is little studied. The objective of this ...

  4. Estuaries May Face Increased Parasitism as Sea Levels Rise

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-12-01

    Invertebrates in estuaries could be at a greater risk of parasitism as climate change causes sea levels to rise. A new paper published 8 December in Proceedings of the National Academy of Sciences of the United States of America (doi:10.1073/pnas.1416747111) describes how rapid sea level rise in the Holocene affected the population of parasitic flatworms called trematodes.

  5. Parasitism of Dasineura oxycoccana (Diptera: Cecidomyiidae) in North Central Florida.

    PubMed

    Roubos, Craig R; Liburd, Oscar E

    2013-06-01

    Blueberry gall midge, Dasineura oxycoccana (Johnson), is a key pest of blueberries in Florida. As a larva, this insect feeds in developing flower and leaf buds. Management of D. oxycoccana relies principally on chemical insecticides; however, efficacy is limited because D. oxycoccana is sheltered within the plant during most of its life cycle. Natural enemies, particularly parasitoids, may play an important role in regulating D. oxycoccana populations. To determine the seasonal dynamics and parasitism rates of eulophid and platygastrid wasps parasitizing D. oxycoccana larvae, we sampled D. oxycoccana larvae by collecting infested blueberry leaf buds from a minimally-managed farm in north central Florida. Midge larvae were examined under a microscope to determine parasitism status of host instars. Parasitism rates ranged from 25 to 40% over the 3-yr study. Percent parasitization was significantly higher in third instars than first or second instars. Midge larvae in the centers of leaf buds were significantly less likely to be parasitized than larvae in outer layers of leaf buds. Thirty-seven percent of midge larvae had been parasitized multiple times, suggesting these parasitoids do not discriminate between parasitized and unparasitized hosts. Implications for pesticide use in relation to the conservation of natural enemies and management of D. oxycoccana populations are discussed. PMID:23726050

  6. Prevalence and etiology of intestinal parasites in Lebanon.

    PubMed

    Araj, G F; Abdul-Baki, N Y; Hamze, M M; Alami, S Y; Nassif, R E; Naboulsi, M S

    1996-01-01

    As there are no studies done on the prevalence of intestinal parasites in Lebanon since 1967, this study was undertaken to reveal the current patterns of intestinal parasitic infestations in Lebanese patients from two geographic regions: Beirut and Tripoli. Analysis was based on 33,253 stool specimens examined at the American University of Beirut Medical Center (AUH) and 11,611 specimens examined at the Islamic Hospital (IH) in Tripoli over five and three years, respectively. The prevalence of intestinal parasites at AUH and IH were 8.47% and 45.35%, respectively (overall 18%). The prevalence in males vs females was almost the same; being 8.23% vs 8.74%, and 44.67% vs 45.88%, at AUH and IH, respectively. Multiple infections were noted in 8.8% and 3.5% of stool specimens at AUH and IH, respectively. Although 18 different types of parasites were encountered, the most common pathogenic parasites found at AUH vs IH were: Giardia lamblia (20.7% vs 10.5% of parasites found), Entamoeba histolytica (19.41% vs 1.25%), Taenia spp. (6.03% vs 4.08%) and Ascaris lumbricoides (2.09% vs 46.97%). The overall yearly or monthly prevalence of parasites recovered from both hospitals did not show clear seasonal patterns. Compared to developed countries, Lebanon still suffers from a high prevalence and a wide spectrum of intestinal parasites. PMID:9260400

  7. Monarch butterfly migration and parasite transmission in eastern North America.

    PubMed

    Bartel, Rebecca A; Oberhauser, Karen S; De Roode, Jacobus C; Altizer, Sonia M

    2011-02-01

    Seasonal migration occurs in many animal systems and is likely to influence interactions between animals and their parasites. Here, we focus on monarch butterflies (Danaus plexippus) and a protozoan parasite (Ophryocystis elektroscirrha) to investigate how host migration affects infectious disease processes. Previous work showed that parasite prevalence was lower among migratory than nonmigratory monarch populations; two explanations for this pattern are that (1) migration allows animals to periodically escape contaminated habitats (i.e., migratory escape), and (2) long-distance migration weeds out infected animals (i.e., migratory culling). We combined field-sampling and analysis of citizen science data to examine spatiotemporal trends of parasite prevalence and evaluate evidence for these two mechanisms. Analysis of within-breeding-season variation in eastern North America showed that parasite prevalence increased from early to late in the breeding season, consistent with the hypothesis of migratory escape. Prevalence was also positively related to monarch breeding activity, as indexed by larval density. Among adult monarchs captured at different points along the east coast fall migratory flyway, parasite prevalence declined as monarchs progressed southward, consistent with the hypothesis of migratory culling. Parasite prevalence was also lower among monarchs sampled at two overwintering sites in Mexico than among monarchs sampled during the summer breeding period. Collectively, these results indicate that seasonal migration can affect parasite transmission in wild animal populations, with implications for predicting disease risks for species with threatened migrations. PMID:21618914

  8. Assessing the Effects of Climate on Host-Parasite Interactions: A Comparative Study of European Birds and Their Parasites

    PubMed Central

    Møller, Anders Pape; Merino, Santiago; Soler, Juan José; Antonov, Anton; Badás, Elisa P.; Calero-Torralbo, Miguel A.; de Lope, Florentino; Eeva, Tapio; Figuerola, Jordi; Flensted-Jensen, Einar; Garamszegi, Laszlo Z.; González-Braojos, Sonia; Gwinner, Helga; Hanssen, Sveinn Are; Heylen, Dieter; Ilmonen, Petteri; Klarborg, Kurt; Korpimäki, Erkki; Martínez, Javier; Martínez-de la Puente, Josue; Marzal, Alfonso; Matthysen, Erik; Matyjasiak, Piotr; Molina-Morales, Mercedes; Moreno, Juan; Mousseau, Timothy A.; Nielsen, Jan Tøttrup; Pap, Péter László; Rivero-de Aguilar, Juan; Shurulinkov, Peter; Slagsvold, Tore; Szép, Tibor; Szöllősi, Eszter; Török, Janos; Vaclav, Radovan; Valera, Francisco; Ziane, Nadia

    2013-01-01

    Background Climate change potentially has important effects on distribution, abundance, transmission and virulence of parasites in wild populations of animals. Methodology/Principal Finding Here we analyzed paired information on 89 parasite populations for 24 species of bird hosts some years ago and again in 2010 with an average interval of 10 years. The parasite taxa included protozoa, feather parasites, diptera, ticks, mites and fleas. We investigated whether change in abundance and prevalence of parasites was related to change in body condition, reproduction and population size of hosts. We conducted analyses based on the entire dataset, but also on a restricted dataset with intervals between study years being 5–15 years. Parasite abundance increased over time when restricting the analyses to datasets with an interval of 5–15 years, with no significant effect of changes in temperature at the time of breeding among study sites. Changes in host body condition and clutch size were related to change in temperature between first and second study year. In addition, changes in clutch size, brood size and body condition of hosts were correlated with change in abundance of parasites. Finally, changes in population size of hosts were not significantly related to changes in abundance of parasites or their prevalence. Conclusions/Significance Climate change is associated with a general increase in parasite abundance. Variation in laying date depended on locality and was associated with latitude while body condition of hosts was associated with a change in temperature. Because clutch size, brood size and body condition were associated with change in parasitism, these results suggest that parasites, perhaps mediated through the indirect effects of temperature, may affect fecundity and condition of their hosts. The conclusions were particularly in accordance with predictions when the restricted dataset with intervals of 5–15 years was used, suggesting that short

  9. Fleas parasitizing domestic dogs in Spain.

    PubMed

    Gracia, M J; Calvete, C; Estrada, R; Castillo, J A; Peribáñez, M A; Lucientes, J

    2008-02-14

    In addition to their importance to veterinary clinical practice as ectoparasites, fleas of domestic dogs are of special concern because they can be vectors of disease, including zoonoses. Flea assemblages parasitizing domestic dogs usually comprise several flea species whose distribution is determined by factors acting at several scales. Knowledge of these factors will aid in assessment of the distribution patterns of flea parasitism, and is an important tool in developing control strategies and in evaluation of flea-borne disease risk in dogs and humans. In this survey we used data from 744 domestic dogs from 79 localities in Spain to explore the associations between the abundance of flea species, host-dependent factors (sex and age), and host habitat factors including abode (farm, house with garden, apartment), location (urban or rural), the presence of other pets, and dog activity (measured as the frequency with which dogs left their abode). We also considered environmental factors including the time of year and mean annual temperature and rainfall. Variations in flea community structure at infracommunity and component community levels were also explored. Four flea species were found parasitizing dogs. Ctenocephalides felis was the most abundant (88.02% of fleas identified), followed by Ctenocephalides canis (10.38%), Pulex irritans (1.47%) and Echidnophaga gallinacea (0.13%). Overall flea abundance was higher on dogs living on farms than in apartments, as was the abundance of Ct. felis, Ct. canis and P. irritans. Ct. felis was more abundant on dogs living in houses than in apartments, but the reverse was found for P. irritans. Overall flea abundance and Ct. canis abundance were highest in rural areas, whereas the presence of other pets sharing the abode was associated with higher overall flea abundance and Ct. felis abundance. Only P. irritans abundance was positively related to the activity of dogs. Ct. canis and P. irritans abundances were higher during the

  10. Are adequate methods available to detect protist parasites on fresh produce?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human parasitic protists such as Cryptosporidium, Giardia and microsporidia contaminate a variety of fresh produce worldwide. Existing detection methods lack sensitivity and specificity for most foodborne parasites. Furthermore, detection has been problematic because these parasites adhere tenacious...

  11. Myxosporean parasites in Australian frogs: Importance, implications and future directions

    PubMed Central

    Hartigan, Ashlie; Phalen, David N.; Šlapeta, Jan

    2013-01-01

    Myxosporean parasites have been identified in amphibians around the world yet very little is known about their diversity, biology and host impact. Several species of Australian frogs have recently been shown to be affected by myxosporidiosis caused by two new Cystodiscus species. In this manuscript, we review what is known about the myxosporean parasites Cystodiscus australis and Cystodiscus axonis that produce myxospores in gallbladders of Australian frogs and Myxobolus fallax and Myxobolus hylae that produce spores in gonads and the potential impact of these parasites on the conservation of Australian frogs. By doing so, we aim to highlight the importance of amphibian myxosporean parasites, suggest directions for future research and argue that the lessons learned about these parasites in Australia are directly transferable to amphibians around the world. PMID:24533318

  12. Checklists of Parasites of Farm Fishes of Babylon Province, Iraq.

    PubMed

    Mhaisen, Furhan T; Al-Rubaie, Abdul-Razzak L

    2016-01-01

    Literature reviews of all references concerning the parasitic fauna of fishes in fish farms of Babylon province, middle of Iraq, showed that a total of 92 valid parasite species are so far known from the common carp (Cyprinus carpio), the grass carp (Ctenopharyngodon idella), and the silver carp (Hypophthalmichthys molitrix) as well as from three freshwater fish species (Carassius auratus, Liza abu, and Heteropneustes fossilis) which were found in some fish farms of the same province. The parasitic fauna included one mastigophoran, three apicomplexans, 13 ciliophorans, five myxozoans, five trematodes, 45 monogeneans, five cestodes, three nematodes, two acanthocephalans, nine arthropods, and one mollusc. The common carp was found to harbour 81 species of parasites, the grass carp 30 species, the silver carp 28 species, L. abu 13 species, C. auratus one species, and H. fossilis one species. A host-parasite list for each fish species was also provided. PMID:27559480

  13. Genetic diversity, parasite prevalence and immunity in wild bumblebees

    PubMed Central

    Whitehorn, Penelope R.; Tinsley, Matthew C.; Brown, Mark J. F.; Darvill, Ben; Goulson, Dave

    2011-01-01

    Inbreeding and a consequent loss of genetic diversity threaten small, isolated populations. One mechanism by which genetically impoverished populations may become extinct is through decreased immunocompetence and higher susceptibility to parasites. Here, we investigate the relationship between immunity and inbreeding in bumblebees, using Hebridean island populations of Bombus muscorum. We sampled nine populations and recorded parasite prevalence and measured two aspects of immunity: the encapsulation response and levels of phenoloxidase (PO). We found that prevalence of the gut parasite Crithidia bombi was higher in populations with lower genetic diversity. Neither measure of immune activity was correlated with genetic diversity. However, levels of PO declined with age and were also negatively correlated with parasite abundance. Our results suggest that as insect populations lose heterozygosity, the impact of parasitism will increase, pushing threatened populations closer to extinction. PMID:20926436

  14. Checklist of Helminth parasites of Amphibians from South America.

    PubMed

    Campião, Karla Magalhães; Morais, Drausio Honorio; Dias, Olívia Tavares; Aguiar, Aline; Toledo, Gislayne De Melo; Tavares, Luiz Eduardo Roland; Da Silva, Reinaldo José

    2014-01-01

    Parasitological studies on helminths of amphibians in South America have increased in the past few years. Here, we present a list with summarized data published on helminths of South American amphibians from 1925 to 2012, including a list of helminth parasites, host species, and geographic records. We found 194 reports of helminths parasitizing 185 amphibian species from eleven countries: Argentina, Brazil, Chile, Colombia, Equador, French Guyana, Guyana, Paraguay, Peru, Uruguay and Venezuela. Helminth biodiversity includes 278 parasite species of the groups Acanthocephala, Nematoda, Cestoda, Monogenea and Trematoda. A list of helminth parasite species per host, and references are also presented. This contribution aims to document the biodiversity of helminth parasites in South American amphibians, as well as identify gaps in our knowledge, which in turn may guide subsequent studies.  PMID:25082165

  15. Checklists of Parasites of Farm Fishes of Babylon Province, Iraq

    PubMed Central

    Al-Rubaie, Abdul-Razzak L.

    2016-01-01

    Literature reviews of all references concerning the parasitic fauna of fishes in fish farms of Babylon province, middle of Iraq, showed that a total of 92 valid parasite species are so far known from the common carp (Cyprinus carpio), the grass carp (Ctenopharyngodon idella), and the silver carp (Hypophthalmichthys molitrix) as well as from three freshwater fish species (Carassius auratus, Liza abu, and Heteropneustes fossilis) which were found in some fish farms of the same province. The parasitic fauna included one mastigophoran, three apicomplexans, 13 ciliophorans, five myxozoans, five trematodes, 45 monogeneans, five cestodes, three nematodes, two acanthocephalans, nine arthropods, and one mollusc. The common carp was found to harbour 81 species of parasites, the grass carp 30 species, the silver carp 28 species, L. abu 13 species, C. auratus one species, and H. fossilis one species. A host-parasite list for each fish species was also provided. PMID:27559480

  16. Epigenetic Regulation of Virulence Gene Expression in Parasitic Protozoa.

    PubMed

    Duraisingh, Manoj T; Horn, David

    2016-05-11

    Protozoan parasites colonize numerous metazoan hosts and insect vectors through their life cycles, with the need to respond quickly and reversibly while encountering diverse and often hostile ecological niches. To succeed, parasites must also persist within individuals until transmission between hosts is achieved. Several parasitic protozoa cause a huge burden of disease in humans and livestock, and here we focus on the parasites that cause malaria and African trypanosomiasis. Efforts to understand how these pathogens adapt to survive in varied host environments, cause disease, and transmit between hosts have revealed a wealth of epigenetic phenomena. Epigenetic switching mechanisms appear to be ideally suited for the regulation of clonal antigenic variation underlying successful parasitism. We review the molecular players and complex mechanistic layers that mediate the epigenetic regulation of virulence gene expression. Understanding epigenetic processes will aid the development of antiparasitic therapeutics. PMID:27173931

  17. Fluctuating asymmetry and parasitism in six New Zealand insects

    NASA Astrophysics Data System (ADS)

    Ward, Darren F.; Thomas, Frédéric; Poulin, Robert

    1998-10-01

    Positive associations between parasitic infections and developmental instability are often reported in the literature. In some cases, developmentally unstable individuals are of lower genetic quality and more prone to infection, whereas in other cases, parasites appear to directly cause developmental instability. We determined whether parasitism correlated with fluctuating asymmetry in femur length, a measure of developmental instability, in two species of cockroaches harbouring benign nematodes, and four species of grasshoppers infected with harmful gregarine protozoans. We found no evidence that the more asymmetrical individuals were more heavily parasitized, in either of the six insect species. These results provide several exceptions to the pattern generally reported in the recent literature, and suggest that, at least among insects, fluctuating asymmetry and parasitism are not always associated.

  18. The evolution of host specialisation in avian brood parasites.

    PubMed

    Medina, Iliana; Langmore, Naomi E

    2016-09-01

    Traditional ecological theory predicts that specialisation can promote speciation; hence, recently derived species are specialists. However, an alternative view is that new species have broad niches, which become narrower and specialised over time. Here, we test these hypotheses using avian brood parasites and three different measures of host specialisation. Brood parasites provide an ideal system in which to investigate the evolution of specialisation, because some exploit more than 40 host species and others specialise on only one. We find that young brood parasite species are smaller and specialise on a narrower range of host sizes, as expected, if specialisation is linked with the generation of new species. Moreover, we show that highly virulent parasites are more specialised, supporting findings in other host-parasite systems. Finally, we demonstrate that different measures of specialisation can lead to different conclusions, and specialisation indices should be designed taking into account the biology of each system. PMID:27417381

  19. Parasite calcineurin regulates host cell recognition and attachment by apicomplexans

    PubMed Central

    Paul, Aditya S.; Saha, Sudeshna; Engelberg, Klemens; Jiang, Rays H.Y.; Coleman, Bradley I.; Kosber, Aziz L.; Chen, Chun-Ti; Ganter, Markus; Espy, Nicole; Gilberger, Tim W.; Gubbels, Marc-Jan; Duraisingh, Manoj T.

    2015-01-01

    SUMMARY Apicomplexans invade a variety of metazoan host cells through mechanisms involving host cell receptor engagement and secretion of parasite factors to facilitate cellular attachment. We find that the parasite homolog of calcineurin, a calcium-regulated phosphatase complex central to signal transduction in eukaryotes, also contributes to host cell invasion by the malaria parasite Plasmodium falciparum and related Toxoplasma gondii. Using reverse genetic and chemical-genetic approaches, we determine that calcineurin critically regulates and stabilizes attachment of extracellular P. falciparum to host erythrocytes before intracellular entry and has similar functions in host cell engagement by T. gondii. Calcineurin-mediated Plasmodium invasion is strongly associated with host receptors required for host cell recognition and calcineurin function distinguishes this form of receptor-mediated attachment from a second mode of host-parasite adhesion independent of host receptors. This specific role of calcineurin in coordinating physical interactions with host cells highlights an ancestral mechanism for parasitism used by apicomplexans. PMID:26118996

  20. [How does the apicomplexan parasite Theileria control host cell identity?].

    PubMed

    Marsolier, Justine; Weitzman, Jonathan B

    2014-01-01

    Infectious agents, like bacteria or virus, are responsible for a large number of pathologies in mammals. Microbes have developed mechanisms for interacting with host cell pathways and hijacking cellular machinery to change the phenotypic state. In this review, we focus on an interesting apicomplexan parasite called Theileria. Infection by the tick-transmitted T. annulata parasite causes Tropical Theileriosis in North Africa and Asia, and the related T. parva parasite causes East Coast Fever in Sub-Saharan Africa. This parasite is the only eukaryote known to induce the transformation of its mammalian host cells. Indeed, T. annulata and T. parva infect bovine leukocytes leading to transforming phenotypes, which partially mirror human lymphoma pathologies. Theileria infection causes hyperproliferation, invasiveness and escape from apoptosis, presumably through the manipulation of host cellular pathways. Several host-signaling mechanisms have been implicated. Here we describe the mechanisms involved in parasite-induced transformation phenotypes. PMID:25840458