Sample records for protozoan phylum apicomplexa

  1. Phylum Apicomplexa Plasmodium, Gregarina

    E-print Network

    Cochran-Stafira, D. Liane

    in animal cells Cell-piercing structure made of microtubules Reproduce sexually and asexually in host cells and cytoskeletal structures that enables the young parasite to enter a host cell. Several components Two apical of apicoplast DNA shows it is closely related to chloroplasts (Chlamydomonas) Potential drug target ­ kill

  2. Dynamic organization of microtubules and microtubule-organizing centers during the sexual phase of a parasitic protozoan, Lecudina tuzetae (Gregarine, Apicomplexa).

    PubMed

    Kuriyama, Ryoko; Besse, Colette; Gèze, Marc; Omoto, Charlotte K; Schrével, Joseph

    2005-12-01

    Lecudina tuzetae is a parasitic protozoan (Gregarine, Apicomplexa) living in the intestine of a marine polychaete annelid, Nereis diversicolor. Using electron and fluorescence microscopy, we have characterized the dynamic changes in microtubule organization during the sexual phase of the life cycle. The gametocyst excreted from the host worm into seawater consists of two (one male and one female) gamonts in which cortical microtubule arrays are discernible. Each gamont undergoes multiple nuclear divisions without cytokinesis, resulting in the formation of large multinucleate haploid cells. After cellularization, approximately 1000 individual gametes are produced from each gamont within 24 h. Female gametes are spherical and contain interphase cytoplasmic microtubule arrays emanating from a gamma-tubulin-containing site. In male gametes, both interphase microtubules and a flagellum with "6 + 0" axonemal microtubules extend from the same microtubule-organizing site. At the beginning of spore formation, each zygote secretes a wall to form a sporocyst. Following meiotic and mitotic divisions, each sporocyst gives rise to eight haploid cells that ultimately differentiate into sporozoites. The ovoid shaped sporocyst is asymmetric and forms at least two distinctive microtubule arrays: spindle microtubules and microtubule bundles originating from the protruding apical end corresponding to the dehiscence pole of the sporocyst. Because antibodies raised against mammalian centrosome components, such as gamma-tubulin, pericentrin, Cep135, and mitosis-specific phosphoproteins, react strongly with the microtubule-nucleating sites of Lecudina, this protozoan is likely to share common centrosomal antigens with higher eukaryotes. PMID:16240430

  3. Phylum Cnidaria Origin of Diversity

    E-print Network

    Cochran-Stafira, D. Liane

    1 Phylum Cnidaria Origin of Diversity How has so much diversity been possible in the Phylum Cnidaria 1. Polyp and medusa forms ­ Provide the basic diversity by offering two different ways of life diversity been possible in the Phylum Cnidaria 2. Colony formation ­ Most common results of budding ability

  4. Lateral gene transfer of family A DNA polymerases between thermophilic viruses, aquificae, and apicomplexa.

    PubMed

    Schoenfeld, Thomas W; Murugapiran, Senthil K; Dodsworth, Jeremy A; Floyd, Sally; Lodes, Michael; Mead, David A; Hedlund, Brian P

    2013-07-01

    Bioinformatics and functional screens identified a group of Family A-type DNA Polymerase (polA) genes encoded by viruses inhabiting circumneutral and alkaline hot springs in Yellowstone National Park and the US Great Basin. The proteins encoded by these viral polA genes (PolAs) shared no significant sequence similarity with any known viral proteins but were remarkably similar to PolAs encoded by two of three families of the bacterial phylum Aquificae and by several apicoplast-targeted PolA-like proteins found in the eukaryotic phylum Apicomplexa, which includes the obligate parasites Plasmodium, Babesia, and Toxoplasma. The viral gene products share signature elements previously associated only with Aquificae and Apicomplexa PolA-like proteins and were similar to proteins encoded by prophage elements of a variety of otherwise unrelated Bacteria, each of which additionally encoded a prototypical bacterial PolA. Unique among known viral DNA polymerases, the viral PolA proteins of this study share with the Apicomplexa proteins large amino-terminal domains with putative helicase/primase elements but low primary sequence similarity. The genomic context and distribution, phylogeny, and biochemistry of these PolA proteins suggest that thermophilic viruses transferred polA genes to the Apicomplexa, likely through secondary endosymbiosis of a virus-infected proto-apicoplast, and to the common ancestor of two of three Aquificae families, where they displaced the orthologous cellular polA gene. On the basis of biochemical activity, gene structure, and sequence similarity, we speculate that the xenologous viral-type polA genes may have functions associated with diversity-generating recombination in both Bacteria and Apicomplexa. PMID:23608703

  5. Efficacy of eleven antimicrobials against a gregarine parasite (Apicomplexa: Protozoa)

    PubMed Central

    Johny, Shajahan; Merisko, Amber; Whitman, Douglas W

    2007-01-01

    Background The Apicomplexa are a diverse group of obligate protozoan parasites infesting a wide range of invertebrate and vertebrate hosts including humans. These parasites are notoriously difficult to control and many species continue to evolve resistance to commercial antibiotics. In this study, we sought to find an effective chemotherapeutic treatment against arthropod gregarines (Apicomplexa), and to identify candidate compounds for testing against other groups of protozoan parasites. Methods We tested eleven commercial antibiotics against a gregarine parasite of Romalea microptera grasshoppers. Infected insects were fed daily, lettuce containing known amounts of specific antibiotics. On Days 15 or 20, we measured the number of gregarines remaining in the digestive tract of each grasshopper. Results Treatment with metronidazole and griseofulvin in host insects significantly reduced gregarine counts, whereas, gregarine counts of insects fed, albendazole, ampicillin, chloramphenicol, fumagillin, quinine, streptomycin, sulfadimethoxine, thiabendazole or tetracycline, were not significantly different from the controls. However, albendazole produced a strong, but non-significant reduction in gregarine count, and streptomycin exhibited a non-significant antagonistic trend. Conclusion Our results confirm that gregarine infections are difficult to control and suggest the possibility that streptomycin might aggravate gregarine infection. In addition, the insect system described here, provides a simple, inexpensive, and effective method for screening antibiotics. PMID:17997852

  6. First report of Calyptospora sp. (Apicomplexa, Calyptosporidae) in forage characid fish from the Três Marias Reservoir, São Francisco Basin, Brazil.

    PubMed

    de Albuquerque, Marcia Cavalcanti; de Carvalho Brasil-Sato, Marilia

    2010-05-01

    Coccidians are parasitic protozoans, and Calyptospora is an important genus of coccidia found in freshwater and marine fish of the Americas. This paper describes Calyptospora sp. that were found parasitizing the liver and intestine of Triportheus guentheri and the intestine of Tetragonopterus chalceus, two forage fish species from the Três Marias Reservoir, Upper São Francisco River, State of Minas Gerais, Brazil. Apicomplexa found in the São Francisco Basin are reported here for the first time. PMID:20163938

  7. Proteases of Protozoan Parasites

    Microsoft Academic Search

    Philip J. Rosenthal

    1999-01-01

    Proteolytic enzymes seem to play important roles in the life cycles of all medically important protozoan parasites, including the organisms that cause malaria, trypanosomiasis, leishmaniasis, amebiasis, toxoplasmosis, giardiasis, cryptosporidiosis and trichomoniasis. Proteases from all four major proteolytic classes are utilized by protozoans for diverse functions, including the invasion of host cells and tissues, the degradation of mediators of the immune

  8. A feast of protozoan genomes

    Microsoft Academic Search

    Christiane Hertz-Fowler; Matthew Berriman; Arnab Pain

    2005-01-01

    The recent completion of five new protozoan parasite genomes should lead to an improved understanding of their biology and, through comparative genomics, shed light on protozoan genome diversity and evolution.

  9. Canine protozoan polyradiculoneuritis

    Microsoft Academic Search

    J. F. Cummings; A. Lahunta; M. M. Suter; R. H. Jacobson

    1988-01-01

    Four pups in a litter of eight Labrador Retrievers suddenly developed hind limb weakness. In three, paralysis ascended rapidly resulting in quadriplegia, cervical weakness, dysphagia and death. Postmortem examination revealed a severe polyradiculoneuritis in which roots, ganglia, and spinal and cranial nerves were heavily infiltrated by lymphocytes, plasma cells and macrophages and contained abundant protozoan pseudocysts. On sections of the

  10. Protozoan Cell Cycle Control

    Microsoft Academic Search

    Joseph T. Y. Wong

    1996-01-01

    Many genes belonging to the cyclin-dependent kinase (cdk) family have been isolated from protozoans. While their role in cell cycle has yet to be proven unequivocally, at least one cdk can complement the cdc2ts\\/cdc28tsmutants in yeasts. Among the interesting questions relating to cdks in protozoa are: whether one cdk acts throughout the whole cell cycle and whether cyclin partnership is

  11. Waterborne protozoan pathogens.

    PubMed Central

    Marshall, M M; Naumovitz, D; Ortega, Y; Sterling, C R

    1997-01-01

    Protozoan parasites were the most frequently identified etiologic agents in waterborne disease outbreak from 1991 to 1994. The waterborne parasites Giardia lamblia, Naegleria fowleri, Acanthamoeba spp., Entamoeba histolytica, Cryptosporidium parvum, Cyclospora cayetanesis, Isospora belli, and the microsporidia are reviewed. For each parasite, the review includes history, life cycle, incidence, symptoms, and therapy. Clinical detection methods are compared, and emerging technologies are discussed. Information on the association of these parasites with waterborne outbreaks is reviewed. Current information on protozoan parasites identified as etiological agents in waterborne outbreaks is discussed. Water industry issues related to recent disease outbreaks are examined in the context of water quality testing regulations for G. lamblia and those proposed for C. parvum. The review identifies the limitations of the American Society of Testing and Materials water-testing method for these parasites. An overview of federal regulations affecting the water industry and laboratories that test for water quality is also provided. The article highlights the importance of the clinical laboratory as a frontline defense for the detection of infectious organisms. The review points to the need for clinical laboratories, physicians, and public health personnel to cooperatively plan and assess the challenge of meeting this potential public health threat. PMID:8993859

  12. TRAP Is Necessary for Gliding Motility and Infectivity of Plasmodium Sporozoites

    Microsoft Academic Search

    Ali A. Sultan; Vandana Thathy; Ute Frevert; Kathryn J. H. Robson; Andrea Crisanti; Victor Nussenzweig; Ruth S. Nussenzweig; Robert Ménard

    1997-01-01

    Many protozoans of the phylum Apicomplexa are invasive parasites that exhibit a substrate-dependent gliding motility. Plasmodium (malaria) sporozoites, the stage of the parasite that invades the salivary glands of the mosquito vector and the liver of the vertebrate host, express a surface protein called thrombospondin-related anonymous protein (TRAP) that has homologs in other Apicomplexa. By gene targeting in a rodent

  13. Comparative genomics of the Rab protein family in Apicomplexan parasites

    Microsoft Academic Search

    Gordon Langsley; Vera van Noort; Céline Carret; Markus Meissner; Etienne P. de Villiers; Richard Bishop; Arnab Pain

    2008-01-01

    Rab genes encode a subgroup of small GTP-binding proteins within the ras super-family that regulate targeting and fusion of transport vesicles within the secretory and endocytic pathways. These genes are of particular interest in the protozoan phylum Apicomplexa, since a family of Rab GTPases has been described for Plasmodium and most putative secretory pathway proteins in Apicomplexa have conventional predicted

  14. The genus atoxoplasma (Protozoa, Apicomplexa).

    PubMed

    Levine, N D

    1982-08-01

    The apicomplexan protozoan genus Atoxoplasma Garnham, 1950 is resurrected and the family Atoxoplasmatidae n. fam. established for homoxenous blood parasites of birds that develop asexually in both the blood and intestinal cells, and form oocysts that are passed unsporulated in the feces, sporulate on the ground, and then infect new hosts. A list of 19 species of Atoxoplasma is given. Atoxoplasma desseri n. sp. of the evening grosbeak Coccothraustes vespertinus and rose-breasted grosbeak Pheucticus ludovicianus is named. PMID:7119994

  15. Foodborne protozoan parasites.

    PubMed

    Dawson, David

    2005-08-25

    This report addresses Cryptosporidium, Giardia, Cyclospora, and more briefly, Toxoplasma as the main parasitic protozoa of concern to food production worldwide. Other parasitic protozoa may be spread in food or water but are not considered as great a risk to food manufacture. The protozoan parasites Cryptosporidium, Giardia, and Cyclospora have proven potential to cause waterborne and foodborne disease. Toxoplasma gondii has been considered a risk in specific cases, but humans are not its primary host. Cryptosporidium and Giardia are widespread in the environment, particularly the aquatic environment, and major outbreaks of cryptosporidiosis and giardiasis have occurred as a result of contaminated drinking water. Large outbreaks of waterborne cyclosporiasis have not been identified. Cryptosporidium, Giardia, and Cyclospora have potential significance in the preparation and consumption of fresh produce and in catering practice, in which ready-to-eat foods may be served that have not received heat treatment. None of the three organisms Cryptosporidium, Giardia, and Cyclospora has been shown to be a problem for heat processed food or tap water that has undergone appropriate treatment at a water treatment works. All three are sensitive to standard pasteurisation techniques. Although humans are not a primary host for T. gondii, the potential exists for both waterborne and foodborne toxoplasmosis. Parasitic protozoa do not multiply in foods, but they may survive in or on moist foods for months in cool, damp environments. Their ecology makes control of these parasites difficult. For general control of parasitic protozoa in the food chain, the following steps are necessary: - Follow good hygienic practice in food service and catering industries.- Minimise dissemination of cysts and oocysts in the farming environment and via human waste management.- Include these microorganisms in Hazard Analysis Critical Control Point (HACCP) plans of water suppliers, industries or sectors that use fresh produce, and operations in which contaminated process or ingredient water could end up in the product (e.g., where water supplies may become contaminated). PMID:16083823

  16. The Ciliate Colpoda: "Instant" Protozoan

    ERIC Educational Resources Information Center

    Smith, Anne Muller; Giese, Arthur C.

    1973-01-01

    Describes the characteristics of Colpoda, a ciliated protozoan which is able to survive in a dry, encysted state for long periods of time. Outlines the procedures for culturing the organism and producing cyst preparations, and recommends its use in the high school biology laboratory. (JR)

  17. MFR PAPER 1342 Some Protozoan Diseases of

    E-print Network

    MFR PAPER 1342 Some Protozoan Diseases of Decapod Crustaceans Thomas K. Sawyer and Sharon A. Mac protozoan parasites of decapod crustaceans into a brief summary of species which are deserving of con a bibliographic overview of the species of protozoans that are included here, but rather to summarize some of our

  18. Phylogenetic relationships of Hepatozoon (Haemogregarina) boigae, Hepatozoon sp., Haemogregarina clelandi and Haemoproteus chelodina from Australian reptiles to other Apicomplexa based on cladistic analyses of ultrastructural and life-cycle characters.

    PubMed

    Jakes, K; O'Donoghue, P J; Cameron, S L

    2003-06-01

    The phylogeny of representative haemozoan species of the phylum Apicomplexa was reconstructed by cladistic analyses of ultrastructural and life-cycle characteristics. The analysis incorporated 4 apicomplexans previously not included in phylogenetic reconstructions: Haemogregarina clelandi from the Brisbane River tortoise (Emydura signata), Hepatozoon sp. from the slaty grey snake (Stegonotus cucullatus), Hepatozoon (Haemogregarina) boigae from the brown tree snake (Boiga irregularis), and Haemoproteus chelodina from the saw-shelled tortoise (Elseya latisternum). There was no apparent correlation between parasite phylogeny and that of their vertebrate hosts, but there appeared to be some relationship between parasites and their intermediate hosts, suggestive of parasite/vector co-evolution. PMID:12866793

  19. FLAGELLAR REGENERATION IN PROTOZOAN FLAGELLATES

    Microsoft Academic Search

    Joel L. Rosenbaum; F. M. Child

    1967-01-01

    ABSTRACT The flagella of populations of three protozoan species (Ochromonas, Euglena, and Astasia) were amputated,and allowed to regenerate. The kinetics of regeneration,in all species were characterized,by a lag phase during which,there was no apparent flagellar elongation; this phase was,followed,by elongation,at a rate which,constantly decelerated,, the original length was regained. Inhibition by cycloheximide,applied at the time of flagellar amputation showed,that flagellar

  20. Photoacoustic spectroscopy of man infecting protozoans

    NASA Astrophysics Data System (ADS)

    Acosta-Avalos, D.; Alvarado-Gil, J. J.; Vargas, H.

    1998-08-01

    In this paper the fundamentals of photothermal spectroscopy are presented, special emphasis is done in the obtention of the optical absorption spectra. It is shown that this spectroscopy can be used successfully for the monitoring of protozoans that could infect the human. The usefulness of the technique is illustrated in the special case of Leishmania, where it is possible to find that the stage when the protozoan infect vertebrate cells show important differences in relation to the protozoans infecting insects.

  1. Ionizing radiation promotes protozoan reproduction

    SciTech Connect

    Luckey, T.D.

    1986-11-01

    This experiment was performed to determine whether ionizing radiation is essential for maximum growth rate in a ciliated protozoan. When extraneous ionizing radiation was reduced to 0.15 mrad/day, the reproduction rate of Tetrahymena pyriformis was significantly less (P less than 0.01) than it was at near ambient levels, 0.5 or 1.8 mrad/day. Significantly higher growth rates (P less than 0.01) were obtained when chronic radiation was increased. The data suggest that ionizing radiation is essential for optimum reproduction rate in this organism.

  2. Large, rapidly evolving gene families are at the forefront of host-parasite interactions in Apicomplexa.

    PubMed

    Reid, Adam J

    2015-02-01

    The Apicomplexa is a phylum of parasitic protozoa, which includes the malaria parasite Plasmodium, amongst other species that can devastate human and animal health. The past decade has seen the release of genome sequences for many of the most important apicomplexan species, providing an excellent basis for improving our understanding of their biology. One of the key features of each genome is a unique set of large, variant gene families. Although closely related species share the same families, even different types of malaria parasite have distinct families. In some species they tend to be found at the ends of chromosomes, which may facilitate aspects of gene expression regulation and generation of sequence diversity. In others they are scattered apparently randomly across chromosomes. For some families there is evidence they are involved in antigenic variation, immune regulation and immune evasion. For others there are no known functions. Even where function is unknown these families are most often predicted to be exposed to the host, contain much sequence diversity and evolve rapidly. Based on these properties it is clear that they are at the forefront of host-parasite interactions. In this review I compare and contrast the genomic context, gene structure, gene expression, protein localization and function of these families across different species. PMID:25257746

  3. Barcoding of Arrow Worms (Phylum Chaetognatha) from Three Oceans: Genetic Diversity and Evolution within an Enigmatic Phylum

    Microsoft Academic Search

    Robert M. Jennings; Ann Bucklin; Annelies Pierrot-Bults

    2010-01-01

    Arrow worms (Phylum Chaetognatha) are abundant planktonic organisms and important predators in many food webs; yet, the classification and evolutionary relationships among chaetognath species remain poorly understood. A seemingly simple body plan is underlain by subtle variation in morphological details, obscuring the affinities of species within the phylum. Many species achieve near global distributions, spanning the same latitudinal bands in

  4. INTRODUCTION Toxoplasma gondii is an intracellular protozoan parasite that

    E-print Network

    Morrissette, Naomi

    INTRODUCTION Toxoplasma gondii is an intracellular protozoan parasite that infects a wide variety techniques to images of isolated, frozen-hydrated subpellicular microtubules from the protozoan parasite

  5. 2002 Nature Publishing Group Trypanosomatid protozoans are important parasites

    E-print Network

    Beverley, Stephen M.

    © 2002 Nature Publishing Group REVIEWS Trypanosomatid protozoans are important parasites of humans PARASITE GENETICS COMES OF AGE Stephen M. Beverley Trypanosomatid protozoans cause important diseases

  6. Interferon effects on protozoan infections

    NASA Technical Reports Server (NTRS)

    Sonnenfeld, G.; Wirth, J.; Kierszenbaum, F.; Degee, A. L. W.; Mansfield, J. M.

    1985-01-01

    The effects of interferon (IFN) on mice infected with two different parasitic protozoans, Trypanosoma cruzi and Trypanosoma brucei rhodesiense, are investigated experimentally. The preparation of the cell cultures, IFN and assays, antibody, and the experimental procedures are described. It is observed that in cells treated with IFN-gamma there is an increased association of T. cruzi with murine macrophages and an increase in the killing of T. cruzi by IFN-gamma-treated murine macrophages. For spleen cells infected with T.b. rhodesiense in vitro, it is detected that live trypanosomes cannot induce IFN in cells from normal mice, but can in cells from immunized mice; and that trypanosome-lysates induce IFN in vitro in cells from normal mice. The data suggest that there is a two-step mechanism for mice against T. cruzi and T.b. rhodesiense.

  7. Using the Ciliate Protozoan Vorticella in Teaching.

    ERIC Educational Resources Information Center

    Jones, Alick R.

    1980-01-01

    Describes methods for collection, culture, observation, and making permanent stained preparations of the protozoan vorticella. Suggestions are made for experiments to investigate growth, reproduction, settlement, ecology, feeding, and osmoregulation. (CS)

  8. FLAGELLAR REGENERATION IN PROTOZOAN FLAGELLATES

    PubMed Central

    Rosenbaum, Joel L.; Child, F. M.

    1967-01-01

    The flagella of populations of three protozoan species (Ochromonas, Euglena, and Astasia) were amputated and allowed to regenerate. The kinetics of regeneration in all species were characterized by a lag phase during which there was no apparent flagellar elongation; this phase was followed by elongation at a rate which constantly decelerated as the original length was regained. Inhibition by cycloheximide applied at the time of flagellar amputation showed that flagellar regeneration was dependent upon de novo protein synthesis. This was supported by evidence showing that a greater amount of leucine was incorporated into the proteins of regenerating than nonregenerating flagella. The degree of inhibition of flagellar elongation observed with cycloheximide depended on how soon after flagellar amputation it was applied: when applied to cells immediately following amputation, elongation was almost completely inhibited, but its application at various times thereafter permitted considerable elongation to occur prior to complete inhibition of flagellar elongation. Hence, a sufficient number of precursors were synthesized and accumulated prior to addition of cycloheximide so that their assembly (elongation) could occur for a time under conditions in which protein synthesis had been inhibited. Evidence that the site of this assembly may be at the tip of the elongating flagellum was obtained from radioautographic studies in which the flagella of Ochromonas were permitted to regenerate part way in the absence of labeled leucine and to complete their regeneration in the presence of the isotope. Possible mechanisms which may be operating to control flagellar regeneration are discussed in light of these and other observations. PMID:6033540

  9. Early evolution of eukaryote feeding modes, cell structural diversity, and classification of the protozoan phyla Loukozoa, Sulcozoa, and Choanozoa.

    PubMed

    Cavalier-Smith, Thomas

    2013-05-01

    I discuss how different feeding modes and related cellular structures map onto the eukaryote evolutionary tree. Centrally important for understanding eukaryotic cell diversity are Loukozoa: ancestrally biciliate phagotrophic protozoa possessing a posterior cilium and ventral feeding groove into which ciliary currents direct prey. I revise their classification by including all anaerobic Metamonada as a subphylum and adding Tsukubamonas. Loukozoa, often with ciliary vanes, are probably ancestral to all protozoan phyla except Euglenozoa and Percolozoa and indirectly to kingdoms Animalia, Fungi, Plantae, and Chromista. I make a new protozoan phylum Sulcozoa comprising subphyla Apusozoa (Apusomonadida, Breviatea) and Varisulca (Diphyllatea; Planomonadida, Discocelida, Mantamonadida; Rigifilida). Understanding sulcozoan evolution clarifies the origins from them of opisthokonts (animals, fungi, Choanozoa) and Amoebozoa, and their evolutionary novelties; Sulcozoa and their descendants (collectively called podiates) arguably arose from Loukozoa by evolving posterior ciliary gliding and pseudopodia in their ventral groove. I explain subsequent independent cytoskeletal modifications, accompanying further shifts in feeding mode, that generated Amoebozoa, Choanozoa, and fungi. I revise classifications of Choanozoa, Conosa (Amoebozoa), and basal fungal phylum Archemycota. I use Choanozoa, Sulcozoa, Loukozoa, and Archemycota to emphasize the need for simply classifying ancestral (paraphyletic) groups and illustrate advantages of this for understanding step-wise phylogenetic advances. PMID:23085100

  10. Immune response in the adipose tissue of lean mice infected with the protozoan parasite Neospora caninum.

    PubMed

    Teixeira, Luzia; Moreira, João; Melo, Joana; Bezerra, Filipa; Marques, Raquel M; Ferreirinha, Pedro; Correia, Alexandra; Monteiro, Mariana P; Ferreira, Paula G; Vilanova, Manuel

    2015-06-01

    The adipose tissue can make important contributions to immune function. Nevertheless, only a limited number of reports have investigated in lean hosts the immune response elicited in this tissue upon infection. Previous studies suggested that the intracellular protozoan Neospora caninum might affect adipose tissue physiology. Therefore, we investigated in mice challenged with this protozoan if immune cell populations within adipose tissue of different anatomical locations could be differently affected. Early in infection, parasites were detected in the adipose tissue and by 7 days of infection increased numbers of macrophages, regulatory T (Treg) cells and T-bet(+) cells were observed in gonadal, mesenteric, omental and subcutaneous adipose tissue. Increased expression of interferon-? was also detected in gonadal adipose tissue of infected mice. Two months after infection, parasite DNA was no longer detected in these tissues, but T helper type 1 (Th1) cell numbers remained above control levels in the infected mice. Moreover, the Th1/Treg cell ratio was higher than that of controls in the mesenteric and subcutaneous adipose tissue. Interestingly, chronically infected mice presented a marked increase of serum leptin, a molecule that plays a role in energy balance regulation as well as in promoting Th1-type immune responses. Altogether, we show that an apicomplexa parasitic infection influences immune cellular composition of adipose tissue throughout the body as well as adipokine production, still noticed at a chronic phase of infection when parasites were already cleared from that particular tissue. This strengthens the emerging view that infections can have long-term consequences for the physiology of adipose tissue. PMID:25581844

  11. Isolation of Besnoitia besnoiti from infected cattle in Portugal

    Microsoft Academic Search

    H. C. E. Cortes; Y. Reis; H. Waap; R. Vidal; H. Soares; I. Marques; I. Pereira da Fonseca; I. Fazendeiro; M. L. Ferreira; V. Caeiro; V. Shkap; A. Hemphill; A. Leitão

    2006-01-01

    Besnoitia besnoiti, an obligate intracellular protozoan parasite belonging to the phylum apicomplexa, is the causative agent of bovine besnoitiosis. Besnoitiosis is responsible for significant losses in the cattle industry of Africa and Mediterranean countries due to the high morbidity rate, abortion and infertility in males. The acute stage of disease is associated with the proliferative forms (tachyzoites) and is characterized

  12. Structural Evidence for Actin-like Filaments in Toxoplasma gondii Using High-Resolution Low-Voltage Field Emission Scanning Electron Microscopy

    Microsoft Academic Search

    Heide Schatten; L. David Sibley; Hans Ris

    2003-01-01

    The protozoan parasite Toxoplasma gondii is representative of a large group of parasites within the phylum Apicomplexa, which share a highly unusual motility system that is crucial for locomotion and active host cell invasion. Despite the importance of motility in the pathology of these unicellular organisms, the motor mechanisms for locomotion remain uncertain, largely because only limited data exist about

  13. A Model of Protozoan Movement for Artificial Life.

    E-print Network

    Dorin, Alan

    ABSTRACT A Model of Protozoan Movement for Artificial Life. Alan Dorin, Justin Martin Department of of a Protozoan and a fluid with the density and viscosity of water have e_xtrernely small Reynolds numbers

  14. INFLUENCE OF PROTOZOAN GRAZING ON CONTAMINANT BIODEGRADATION. (R825418)

    EPA Science Inventory

    The influence of protozoan grazing on biodegradation rates in samples from contaminated aquifer sediment was evaluated under aerobic and anaerobic conditions. Predator¯prey biomass ratios suggested that protozoan grazing might be influencing bacterial populations....

  15. The phylum Cnidaria: A review of phylogenetic patterns and diversity 300 years after Linnaeus

    E-print Network

    Daly, Marymegan; Brugler, Mercer R.; Cartwright, Paulyn; Collins, Allen G.; Dawson, Michael N.; Fautin, Daphne G.; France, Scott C.; McFadden, Catherine; Opresko, Dennis M.; Rodriguez, Estefania; Romano, Sandra L.; Stake, Joel L.

    2007-12-21

    Systema Naturae includes representatives of every major lineage of the animal phylum Cnidaria. However, Linnaeus did not classify the members of the phylum as is now done, and the diversity of the group is not well ...

  16. Proteomes and transcriptomes of the Apicomplexa – Where’s the message?

    Microsoft Academic Search

    J. M. Wastling; D. Xia; A. Sohal; M. Chaussepied; A. Pain; G. Langsley

    2009-01-01

    The Apicomplexa have some of the most comprehensive and integrated proteome datasets of all pathogenic micro-organisms. Coverage is currently at a level where these data can be used to help predict the potential biological function of proteins in these parasites, without having to defer to measurement of mRNA levels. Transcriptomic data for the Apicomplexa (microarrays, expressed sequence tag (EST) collections,

  17. Inhibition of apoptosis by intracellular protozoan parasites

    Microsoft Academic Search

    Volker T. Heussler; Peter Küenzi; Sven Rottenberg

    2001-01-01

    Protozoan parasites which reside inside a host cell avoid direct destruction by the immune system of the host. The infected cell, however, still has the capacity to counteract the invasive pathogen by initiating its own death, a process which is called programmed cell death or apoptosis. Apoptotic cells are recognised and phagocytosed by macrophages and the parasite is potentially eliminated

  18. How do Protozoan Parasites Survive inside Macrophages?

    Microsoft Academic Search

    C. Bogdan; M. Röllinghoff

    1999-01-01

    During infections with intracellular microbes, macrophages have two roles. On the one hand, they are important effector cells for the control and killing of intracellular bacteria and protozoan parasites by oxidative and non-oxidative mechanisms. On the other hand, macrophages may also serve as long-term host cells that facilitate the replication and survival of the pathogens, for example, by protecting them

  19. Culturing and Using Protozoans in the Laboratory.

    ERIC Educational Resources Information Center

    Hummer, Paul J., Jr.

    1993-01-01

    Provides instructions for teachers and students to culture protozoans for use in science laboratories. Sections include setting up a culture area, basic culture media, amoeba culture technique, powdered milk-wheat-rice medium, alfalfa medium, and uses of the protozoa in the laboratory. (PR)

  20. An Expanded Genomic Representation of the Phylum Cyanobacteria

    PubMed Central

    Soo, Rochelle M.; Skennerton, Connor T.; Sekiguchi, Yuji; Imelfort, Michael; Paech, Samuel J.; Dennis, Paul G.; Steen, Jason A.; Parks, Donovan H.; Tyson, Gene W.; Hugenholtz, Philip

    2014-01-01

    Molecular surveys of aphotic habitats have indicated the presence of major uncultured lineages phylogenetically classified as members of the Cyanobacteria. One of these lineages has recently been proposed as a nonphotosynthetic sister phylum to the Cyanobacteria, the Melainabacteria, based on recovery of population genomes from human gut and groundwater samples. Here, we expand the phylogenomic representation of the Melainabacteria through sequencing of six diverse population genomes from gut and bioreactor samples supporting the inference that this lineage is nonphotosynthetic, but not the assertion that they are strictly fermentative. We propose that the Melainabacteria is a class within the phylogenetically defined Cyanobacteria based on robust monophyly and shared ancestral traits with photosynthetic representatives. Our findings are consistent with theories that photosynthesis occurred late in the Cyanobacteria and involved extensive lateral gene transfer and extends the recognized functionality of members of this phylum. PMID:24709563

  1. Mobile genetic elements in the bacterial phylum Acidobacteria

    PubMed Central

    Challacombe, Jean; Kuske, Cheryl

    2012-01-01

    Analysis of the genome of Candidatus Solibacter usitatus Ellin6076, a member of the phylum Acidobacteria, revealed a large number of genes associated with mobile genetic elements. These genes encoded transposases, insertion sequence elements and phage integrases. When the amino acid sequences of the mobile element-associated genes were compared, many of them had high (90–100%) amino acid sequence identities, suggesting that these genes may have recently duplicated and dispersed throughout the genome. Although phage integrase encoding genes were prevalent in the Can. S. usitatus Ellin6076 genome, no intact prophage regions were found. This suggests that the Can. S. usitatus Ellin6076 large genome arose by horizontal gene transfer via ancient bacteriophage and/or plasmid-mediated transduction, followed by widespread small-scale gene duplications, resulting in an increased number of paralogs encoding traits that could provide selective metabolic, defensive and regulatory advantages in the soil environment. Here we examine the mobile element repertoire of Can. S. usitatus Ellin6076 in comparison to other genomes from the Acidobacteria phylum, reviewing published studies and contributing some new analyses. We also discuss the presence and potential roles of mobile elements in members of this phylum that inhabit a variety of environments. PMID:23087842

  2. Protozoan infection in the perinatal period.

    PubMed

    Marecki, M; Heeb, K; Zitka, W

    1997-06-01

    Protozoan infections represent an area of concern for advanced practice nurses, particularly those working in rural areas or urban environments with refugee populations and those caring for patients with immunodeficiency-related diseases. Some of these infections have major effects on the fetus and neonate yet pose minimal problems to the mother. Protozoan infections are increasing in prevalence because of poor sanitation, overcrowding, increased foreign travel, and high-risk sexual behaviors. There is a need for public education to promote awareness and prevention of such infections. This emerging public health problem has been reported sporadically in the medical and perinatal nursing literature. This paucity of information may be partly due to the difficulty in diagnosing and managing these infections in the perinatal patient. The article discusses the more common infections caused by protozoa, amebae, and sporozoa: trichomoniasis, giardiasis, amebiasis, and toxoplasmosis. PMID:9214949

  3. The protozoan diseases of hatchery fish

    USGS Publications Warehouse

    Fish, F.F.

    1935-01-01

    Following the somewhat bleak picture painted in the consideration of the bacterial diseases of hatchery fish in the last number of The Progressive Fish Culturist, it is a relief to turn to another large group of fish diseases caused by small, single-celled parasitic animals known as the protozoa. To the hatcheryman, the protozoan diseases of fish are just as important as the bacterial diseases for they are equally destructive if allowed to run unchecked. The protozoan diseases are just as common as those caused by bacteria, particularly at those hatcheries which depend upon lakes or streams for their water supplies. However, a very cheery point of difference exists between these two groups of diseases—the protozoan diseases are easier to recognize and, for the most part, they are exceedingly easy to eradicate. To the hatcheryman who has struggled day and night for weeks in an attempt to combat an epidemic wherein he is rewarded immediately by the satisfying sight of a complete recovery of his infected fish as the direct result of his labors.

  4. Chapter A7. Section 7.3. Protozoan Pathogens

    USGS Publications Warehouse

    Bushon, Rebecca N.; Francy, Donna S.

    2003-01-01

    Protozoan pathogens are widely distributed in the aquatic environment. Cryptosporidium and Giardia are the principal protozoan pathogens that are known to affect the acceptability of water supplies for public use within the United States. A sampling program for protozoan pathogens should be conducted over an extended period of time because of cyclical and seasonal variations in their concentrations in the environment. This report provides information on the equipment, sampling protocols, and laboratory method that are in standard use by U.S. Geological Survey (USGS) personnel for the collection of data on protozoan pathogens.

  5. Lysine Acetylation Is Widespread on Proteins of Diverse Function and Localization in the Protozoan Parasite Toxoplasma gondii

    PubMed Central

    Jeffers, Victoria

    2012-01-01

    While histone proteins are the founding members of lysine acetylation substrates, it is now clear that hundreds of other proteins can be acetylated in multiple compartments of the cell. Our knowledge of the scope of this modification throughout the kingdom of life is beginning to emerge, as proteome-wide lysine acetylation has been documented in prokaryotes, Arabidopsis thaliana, Drosophila melanogaster, and human cells. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify parasite peptides enriched by immunopurification with acetyl-lysine antibody, we produced the first proteome-wide analysis of acetylation for a protozoan organism, the opportunistic apicomplexan parasite Toxoplasma gondii. The results show that lysine acetylation is abundant in the actively proliferating tachyzoite form of the parasite, which causes acute toxoplasmosis. Our approach successfully identified known acetylation marks on Toxoplasma histones and ?-tubulin and detected over 400 novel acetylation sites on a wide variety of additional proteins, including those with roles in transcription, translation, metabolism, and stress responses. Importantly, an extensive set of parasite-specific proteins, including those found in organelles unique to Apicomplexa, is acetylated in the parasite. Our data provide a wealth of new information that improves our understanding of the evolution of this vital regulatory modification while potentially revealing novel therapeutic avenues. We conclude from this study that lysine acetylation was prevalent in the early stages of eukaryotic cell evolution and occurs on proteins involved in a remarkably diverse array of cellular functions, including those that are specific to parasites. PMID:22544907

  6. ESPÉCIES DO GÊNERO Eimeria (APICOMPLEXA: EIMERIIDAE) EM TAMANDUÁS-BANDEIRA (Myrmecophaga tridactyla LINNAEUS, 1758) EM CATIVEIRO

    Microsoft Academic Search

    FAGNER LUIZ DA C. FREITAS; ANDRÉ S. ZANETTI; CÉLIO R. MACHADO; ROSANGELA Z. MACHADO

    1 ABSTRACT:- FREITAS, F.L. DA C.; ALMEIDA, K. DE S.; ZANETTI, A.S.; NASCIMENTO, A.A. DO; MACHADO, C. R.; MACHADO, R.Z. (Species of the genus Eimeria (Apicomplexa: Eimeriidae) in giant anteaters (Myrmecophaga tridactyla Linnaeus, 1758) in captivity). Espécies do gênero Eimeria (Apicomplexa: Eimeriidae) em Tamanduás-bandeira (Myrmecophaga tridactyla Linnaeus, 1758) em cativeiro. Revista Brasileira de Parasitologia Veterinária, v. 15, n. 1, p.

  7. The major surface-metalloprotease of the parasitic protozoan, Leishmania, protects against antimicrobial

    E-print Network

    Engman, David M.

    The major surface-metalloprotease of the parasitic protozoan, Leishmania, protects against infection by the vector-borne protozoan Leishmania is responsible for substantial worldwide morbidity. Introduction Human infection with the vector-borne protozoan Leish- mania causes substantial worldwide

  8. Epidemiology of parasitic protozoan infections in Soay sheep (Ovis aries L.) on St Kilda

    E-print Network

    Nussey, Dan

    . This paper reports the first epidemiological study of the protozoan species comprising Cryptosporidium parvum, Cryptosporidium parvum, Giardia duodenalis, Eimeria spp. INTRODUCTION Enteric protozoan parasites are ubiquitous

  9. Cross-phylum regulatory potential of the ascidian Otx gene in brain development in Drosophila melanogaster

    Microsoft Academic Search

    Yoshitsugu Adachi; Tomoko Nagao; Hidetoshi Saiga; Katsuo Furukubo-Tokunaga

    2001-01-01

    The origin of molecular mechanisms of cephalic development is an intriguing question in evolutionary and developmental biology. Ascidians, positioned near the origin of the phylum Chordata, share a conserved set of anteroposterior patterning genes with vertebrates. Here we report the cross-phylum regulatory potential of the ascidian Otx gene in the development of the Drosophila brain and the head vertex structures.

  10. Drug repurposing and human parasitic protozoan diseases.

    PubMed

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

    2014-08-01

    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

  11. Pan-phylum Comparison of Nematode Metabolic Potential.

    PubMed

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

    2015-05-01

    Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in C. elegans and the human hookworm Necator americanus. We illustrate how analyzing and comparing metabolism at the level of pathway modules can improve existing knowledge of nematode metabolic potential and can provide parasitism related insights. Our reconstruction and comparison of nematode metabolic pathways at a pan-phylum and inter-phylum level enabled determination of phylogenetic restrictions and differential expression of pathways. A visualization of our results is available at http://nematode.net and the program for identification of module completeness (modDFS) is freely available at SourceForge. The methods reported will help biologists to predict biochemical potential of any organism with available deduced proteome, to direct experiments and test hypotheses. PMID:26000881

  12. Role of Leukotrienes on Protozoan and Helminth Infections

    PubMed Central

    Rogerio, Alexandre P.; Anibal, Fernanda F.

    2012-01-01

    Leukotrienes (LTs), formed by the 5-lipoxygenase-(5-LO-) catalyzed oxidation of arachidonic acid, are lipid mediators that have potent proinflammatory activities. Pharmacologic or genetic inhibition of 5-LO biosynthesis in animals is associated with increased mortality and impaired clearance of bacteria, fungi, and parasites. LTs play a role in the control of helminth and protozoan infections by modulating the immune system and/or through direct cytotoxicity to parasites; however, LTs may also be associated with pathogenesis, such as in cerebral malaria and schistosomal granuloma. Interestingly, some proteins from the saliva of insect vectors that transmit protozoans and secreted protein from helminth could bind LTs and may consequently modulate the course of infection or pathogenesis. In addition, the decreased production of LTs in immunocompromised individuals might modulate the pathophysiology of helminth and protozoan infections. Herein, in this paper, we showed the immunomodulatory and pathogenic roles of LTs during the helminth and protozoan infections. PMID:22577251

  13. Inactivation of protozoan parasites in food, water, and environmental systems.

    PubMed

    Erickson, Marilyn C; Ortega, Ynes R

    2006-11-01

    Protozoan parasites can survive under ambient and refrigerated storage conditions when associated with a range of substrates. Consequently, various treatments have been used to inactivate protozoan parasites (Giardia, Cryptosporidium, and Cyclospora) in food, water, and environmental systems. Physical treatments that affect survival or removal of protozoan parasites include freezing, heating, filtration, sedimentation, UV light, irradiation, high pressure, and ultrasound. Ozone is a more effective chemical disinfectant than chlorine or chlorine dioxide for inactivation of protozoan parasites in water systems. However, sequential inactivation treatments can optimize existing treatments through synergistic effects. Careful selection of methods to evaluate inactivation treatments is needed because many studies that have employed vital dye stains and in vitro excystation have produced underestimations of the effectiveness of these treatments. PMID:17133829

  14. Grazing of acidophilic bacteria by a flagellated protozoan

    Microsoft Academic Search

    Stephen McGinness; D. Barrie Johnson

    1992-01-01

    A biflagellated protozoan was isolated from an acidic drainage stream located inside a disused pyrite mine. The stream contained copious amounts of “acid streamer” bacterial growths, and the flagellate was observed in situ apparently grazing the streamer bacteria. The protozoan was obligately acidophilic, growing between pH 1.8 and 4.5, but not at pH 1.6 or 5.0, with optimum growth between

  15. Correction: Phylogenetic placement of the enigmatic parasite, Polypodium hydriforme, within the Phylum Cnidaria

    E-print Network

    Evans, Nathaniel M.; Lindner, Alberto; Raikova, Ekaterina V.; Collins, Allen G.; Cartwright, Paulyn

    2009-07-15

    ral ssBioMed CentBMC Evolutionary Biology Open AcceCorrection Correction: Phylogenetic placement of the enigmatic parasite, Polypodium hydriforme, within the Phylum Cnidaria Nathaniel M Evans1, Alberto Lindner2, Ekaterina V Raikova3, Allen G.... Phylogenetic placement of the enigmatic parasite, Polypodium hydriforme, within the phylum Cnidaria. BMC Evol Biol, 2008, 8:139. Correction Following the publication of this study [1] it was brought to our attention that the partial 28S rDNA sequence...

  16. Monitoring of stream pollution using protozoan communities on artificial substrates

    SciTech Connect

    Henebry, M.S. (Virginia Polytechnic Inst. and State Univ., Blacksburg); Cairns, J. Jr.

    1980-01-01

    Monitoring of stream pollution using protozoan communities on artificial substrates. Protozoan communities were sampled in 1978 from the South River near Waynesboro, Virginia, and compared with a study carried out in 1972. Five study stations were located above and below sources of pollution. Species richness followed the same pattern as in the 1972 study except at Station 2 (just below a major source of pollution) where a marked improvement in water quality occurred. Numbers of species increased significantly downstream from a source of pollution. This study provides evidence that protozoan communities may be used effectively in the assessment of water pollution and that results compare favorably with those based on macroinvertebrates which are more expensive to collect.

  17. The importance of zooplankton-protozoan trophic couplings in Lake Michigan

    Microsoft Academic Search

    HUNTER J. CARRICK; GARY L. FAHNENSTIEL; EUGENE F. STOERMER; ROBERT G. WETZEL

    1991-01-01

    Abstract The importance,of the zooplankton-protozoan,trophic coupling was determined,experimentally by measured,changes in protozoan,growth rates with increasing zooplankton,biomass. In five of six experiments conducted in Lake Michigan, a significant inverse relationship between protozoan growth and zooplankton biomass was observed (avg r2 = 70%), Zooplankton clearance rates on protozoan assemblages (range, 1.0-6.2 ml (pg dry wt)-I d ‘1 were comparable to those previously

  18. Electing a candidate: a speculative history of the bacterial phylum OP10.

    PubMed

    Dunfield, Peter F; Tamas, Ivica; Lee, Kevin C; Morgan, Xochitl C; McDonald, Ian R; Stott, Matthew B

    2012-12-01

    In 1998, a cultivation-independent survey of the microbial community in Obsidian Pool, Yellowstone National Park, detected 12 new phyla within the Domain Bacteria. These were dubbed 'candidate divisions' OP1 to OP12. Since that time the OP10 candidate division has been commonly detected in various environments, usually as part of the rare biosphere, but occasionally as a predominant community component. Based on 16S rRNA gene phylogeny, OP10 comprises at least 12 class-level subdivisions. However, despite this broad ecological and evolutionary diversity, all OP10 bacteria have eluded cultivation until recently. In 2011, two reference species of OP10 were taxonomically validated, removing the phylum from its 'candidate' status. Construction of a highly resolved phylogeny based on 29 universally conserved genes verifies its standing as a unique bacterial phylum. In the following paper we summarize what is known and what is suspected about the newest described bacterial phylum, the Armatimonadetes. PMID:22497633

  19. Expression of a Bacterial Gene in a Trypanosomatid Protozoan

    Microsoft Academic Search

    Vivian Bellofatto; George A. M. Cross

    1989-01-01

    A simple and reproducible assay for DNA-mediated transfection in the trypanosomatid protozoan Leptomonas seymouri has been developed. The assay is based on expression of the Escherichia coli chloramphenicol acetyl transferase (CAT) gene flanked by Leptomonas DNA fragments that are likely to contain necessary elements for gene expression in trypanosomes. After electroporation of cells in the presence of plasmid DNA, CAT

  20. Programmed cell death in the unicellular protozoan parasite Leishmania

    Microsoft Academic Search

    N Lee; S Bertholet; A Debrabant; J Muller; R Duncan; H L Nakhasi

    2002-01-01

    In the present study we have demonstrated some features characterizing programmed cell death (PCD) in the unicellular protozoan parasite Leishmania donovani, the causative agent of visceral Leishmaniasis. We report that PCD is initiated in stationary phase cultures of promastigotes and both in actively growing cultures of axenic amastigotes and promastigotes upon treatment with anti Leishmanial drugs (Pentostam and amphotericin B).

  1. Biomass control in waste air biotrickling filters by protozoan predation.

    PubMed

    Cox, H H; Deshusses, M A

    1999-01-20

    Two protozoan species as well as an uncharacterized protozoan consortium were added to a toluene-degrading biotrickling filter to investigate protozoan predation as a means of biomass control. Wet biomass formation in 23.6-L reactors over a 77-day period was reduced from 13.875 kg in a control biotrickling filter to 11.795 kg in a biotrickling filter enriched with protozoa. The average toluene vapor elimination capacity at 1 g/m3 toluene and 64 m3/(m3. h) was 31.1 g/(m3. h) in the control and 32.2 g/(m3. h) in the biotrickling filter enriched with protozoa. At higher toluene inlet concentrations, toluene degradation rates increased and were slightly higher in the biotrickling filter enriched with protozoa. The lower rate of biomass accumulation after the addition of protozoa was due to an increase of carbon mineralization (68% as compared to 61% in the control). Apparent biomass yield coefficients in the control and enriched trickling filter were 0.72 and 0.59 g dry biomass/g toluene, respectively. The results show that protozoan predation may be a useful tool to control biomass in biotrickling filters, however, further stimulation of predation of the biomass immobilized in the reactor is required to ensure long-term stability of biotrickling filters. PMID:10099532

  2. Grazing of acidophilic bacteria by a flagellated protozoan.

    PubMed

    McGinness, S; Johnson, D B

    1992-01-01

    A biflagellated protozoan was isolated from an acidic drainage stream located inside a disused pyrite mine. The stream contained copious amounts of "acid streamer" bacterial growths, and the flagellate was observed in situ apparently grazing the streamer bacteria. The protozoan was obligately acidophilic, growing between pH 1.8 and 4.5, but not at pH 1.6 or 5.0, with optimum growth between pH 3 and 4. It was highly sensitive to copper, molybdenum, silver, and uranium, but tolerated ferrous and ferric iron up to 50 and 25 mM, respectively. In the laboratory, the protozoan was found to graze a range of acidophilic bacteria, including the chemolithotrophs Thiobacillus ferrooxidans, Leptospirillum ferrooxidans, and the heterotroph Acidiphilium cryptum. Thiobacillus thiooxidans and Thiobacillus acidophilus were not grazed. Filamentous growth of certain acidophiles afforded some protection against being grazed by the flagellate. In mixed cultures of T. ferrooxidans and L. ferrooxidans, the protozoan isolate displayed preferential grazing of the former. The possibility of using acidophilic protozoa as a means of controlling bacteria responsible for the production of acid mine drainage is discussed. PMID:24192830

  3. CRITERIA FOR EVALUATION OF PROPOSED PROTOZOAN DETECTION METHODS

    EPA Science Inventory

    There has been a proliferation of techniques and methods reported for analysis of water samples to determine the presence of the protozoan pathogens Cryptosporidium parvum and Giardia lamblia. Many of the proposed methods are presented as complete procedures, which include sampli...

  4. CRITERIA FOR EVALUATION OF PROPOSED PROTOZOAN DETECTION METHODS.

    EPA Science Inventory

    There has been a proliferation of techniques and methods reported for analysis of water samples to determine the presence of the protozoan pathogens Cryptosporidium parvum and Giardia lamblia. Many of the proposed methods are presented as complete procedures, which include sampli...

  5. Lipophosphoglycan is a virulence factor distinct from related glycoconjugates in the protozoan parasite

    E-print Network

    Beverley, Stephen M.

    Lipophosphoglycan is a virulence factor distinct from related glycoconjugates in the protozoan of Medicine, St. Louis, MO, June 5, 2000 (received for review April 26, 2000) Protozoan parasites of the genus galactofuranose Protozoan parasites of the genus Leishmania are the causative agent of leishmaniasis, a disease

  6. Assembly-History Dynamics of a Pitcher-Plant Protozoan Community in Experimental Microcosms

    E-print Network

    Miller, Thomas E.

    Assembly-History Dynamics of a Pitcher-Plant Protozoan Community in Experimental Microcosms Kohmei independently in a two-way factorial design to follow community assembly in a three-species aquatic protozoan BD, Miller TE (2012) Assembly-History Dynamics of a Pitcher-Plant Protozoan Community in Experimental

  7. Molecular & Biochemical Parasitology 133 (2004) 4551 Arachidonic acid synthetic pathways of the oyster protozoan parasite,

    E-print Network

    Hartley, Troy W.

    2004-01-01

    of the oyster protozoan parasite, Perkinsus marinus: evidence for usage of a delta-8 pathway Fu-Lin E. Chua Received 24 June 2003; accepted 28 August 2003 Abstract The meront stage of the oyster protozoan parasite; Oyster; Oyster parasite; Perkinsus marinus 1. Introduction Although parasitic protozoans effectively

  8. BIOMASS CONTROL IN WASTE AIR BIOTRICKLING FILTERS BY PROTOZOAN PREDATION. (R825392)

    EPA Science Inventory

    Two protozoan species as well as an uncharacterized protozoan consortium were added to a toluene-degrading biotrickling filter to investigate protozoan predation as a means of biomass control. Wet biomass formation in 23.6-L reactors over a 77-day period was reduced from 13.875 k...

  9. Draft Genome Sequence of Kocuria sp. Strain UCD-OTCP (Phylum Actinobacteria)

    PubMed Central

    Coil, David A.; Doctor, Jessica I.; Lang, Jenna M.; Darling, Aaron E.

    2013-01-01

    Here, we present the draft genome of Kocuria sp. strain UCD-OTCP, a member of the phylum Actinobacteria, isolated from a restaurant chair cushion. The assembly contains 3,791,485 bp (G+C content of 73%) and is contained in 68 scaffolds. PMID:23661474

  10. Class-Level Relationships in the Phylum Cnidaria: Evidence from Mitochondrial Genome Structure

    Microsoft Academic Search

    Diane Bridge; Clifford W. Cunningham; Bernd Schierwater; Rob Desalle; Leo W. Buss

    1992-01-01

    The phylogenetic relationships of the Recent cnidarian classes remain one of the classic problems in invertebrate zoology. We survey the structure of the mitochondrial genome in representatives of the four extant cnidarian classes and in the phylum Ctenophora. We find that all anthozoan species tested possess mtDNA in the form of circular molecules, whereas all scyphozoan, cubozoan, and hydrozoan species

  11. A Broad Molecular Phylogeny of Ciliates: Identification of Major Evolutionary Trends and Radiations within the Phylum

    Microsoft Academic Search

    Anne Baroin-Tourancheau; Pilar Delgado; Roland Perasso; Andre Adoutte

    1992-01-01

    The cellular architecture of ciliates is one of the most complex known within eukaryotes. Detailed systematic schemes have thus been constructed through extensive comparative morphological and ultrastructural analysis of the ciliature and of its internal cytoskeletal derivatives (the infraciliature), as well as of the architecture of the oral apparatus. In recent years, a consensus was reached in which the phylum

  12. Complete Genome of Ignavibacterium album, a Metabolically Versatile, Flagellated, Facultative Anaerobe from the Phylum Chlorobi

    PubMed Central

    Liu, Zhenfeng; Frigaard, Niels-Ulrik; Vogl, Kajetan; Iino, Takao; Ohkuma, Moriya; Overmann, Jörg; Bryant, Donald A.

    2012-01-01

    Prior to the recent discovery of Ignavibacterium album (I. album), anaerobic photoautotrophic green sulfur bacteria (GSB) were the only members of the bacterial phylum Chlorobi that had been grown axenically. In contrast to GSB, sequence analysis of the 3.7-Mbp genome of I. album shows that this recently described member of the phylum Chlorobi is a chemoheterotroph with a versatile metabolism. I. album lacks genes for photosynthesis and sulfur oxidation but has a full set of genes for flagella and chemotaxis. The occurrence of genes for multiple electron transfer complexes suggests that I. album is capable of organoheterotrophy under both oxic and anoxic conditions. The occurrence of genes encoding enzymes for CO2 fixation as well as other enzymes of the reductive TCA cycle suggests that mixotrophy may be possible under certain growth conditions. However, known biosynthetic pathways for several amino acids are incomplete; this suggests that I. album is dependent upon on exogenous sources of these metabolites or employs novel biosynthetic pathways. Comparisons of I. album and other members of the phylum Chlorobi suggest that the physiology of the ancestors of this phylum might have been quite different from that of modern GSB. PMID:22661972

  13. New species of Isospora (Apicomplexa: Eimeriidae) from passeriform birds of Hawaii

    Microsoft Academic Search

    Steve J. Upton; Alan A. Marchiondo; Richard N. Williams

    1988-01-01

    Three new species ofIsospora (Apicomplexa: Eimeriidae) are described from the faeces of passeriform birds of Hawaii.Isospora lyonensis n. sp. is described from the faeces ofLonchura punctulata (Passeriformes: Estrildidae) and has spherical-subspherical oocysts, 24×23 (21–27×21–26.5), with a thick, bi-layered wall c.1.5 thick. A micropyle and oocyst residuum are absent, but three or more polar granules are present. Oocysts ofI. mejiro n.

  14. Protozoan grazing reduces the current output of microbial fuel cells.

    PubMed

    Holmes, Dawn E; Nevin, Kelly P; Snoeyenbos-West, Oona L; Woodard, Trevor L; Strickland, Justin N; Lovley, Derek R

    2015-10-01

    Several experiments were conducted to determine whether protozoan grazing can reduce current output from sediment microbial fuel cells. When marine sediments were amended with eukaryotic inhibitors, the power output from the fuel cells increased 2-5-fold. Quantitative PCR showed that Geobacteraceae sequences were 120times more abundant on anodes from treated fuel cells compared to untreated fuel cells, and that Spirotrichea sequences in untreated fuel cells were 200times more abundant on anode surfaces than in the surrounding sediments. Defined studies with current-producing biofilms of Geobacter sulfurreducens and pure cultures of protozoa demonstrated that protozoa that were effective in consuming G. sulfurreducens reduced current production up to 91% when added to G. sulfurreducens fuel cells. These results suggest that anode biofilms are an attractive food source for protozoa and that protozoan grazing can be an important factor limiting the current output of sediment microbial fuel cells. PMID:26115527

  15. Neutrophils cast extracellular traps in response to protozoan parasites.

    PubMed

    Abi Abdallah, Delbert S; Denkers, Eric Y

    2012-01-01

    Release of extracellular traps by neutrophils is a now well-established phenomenon that contributes to the innate response to extracellular bacterial and fungal pathogens. The importance of NETs during protozoan infection has been less explored, but recent findings suggest an emerging role for release of neutrophil-derived extracellular DNA in response to this class of microbial pathogens. The present review summarizes findings to date regarding elicitation of NETs by Toxoplasma gondii, Plasmodium falciparum, Eimeria bovis, and Leishmania spp. PMID:23248631

  16. Epiphytic protozoans on reed rootlets from Dutch waters

    Microsoft Academic Search

    P. J. Roos; F. J. Trueba

    1977-01-01

    The protozoans attached to the submerged roots of reed (Phragmites australis) in some small waters in Holland were studied during one year. Reed was chosen because it is a very common natural substrate\\u000a for epiphytically living animals. Marked changes in species abundance and overall population density are reported. Most important\\u000a quantitatively were the ciliates, especially peritrichs, on which emphasis is

  17. Detection and in situ identification of representatives of a widely distributed new bacterial phylum

    Microsoft Academic Search

    Wolfgang Ludwig; Stephan H. Bauer; Marc Bauer; Iris Held; Gudrun Kirchhof; Renate Schulze; Ingrid Huber; Stefan Spring; Anton Hartmann; Karl Heinz Schleifer

    1997-01-01

    16S rRNA gene libraries were prepared by polymerase chain reaction amplification and cloning from soil samples taken periodically from a field with genetically modified plants. Sequence analyses of the cloned rDNAs indicated that 140 of them clustered apart from known bacterial phyla. Based on 31 full sequences a new phylum could be defined. It includes Holophaga foetida, `Geothrix fermentans' and

  18. Crystal growth of bullet-shaped magnetite in magnetotactic bacteria of the Nitrospirae phylum.

    PubMed

    Li, Jinhua; Menguy, Nicolas; Gatel, Christophe; Boureau, Victor; Snoeck, Etienne; Patriarche, Gilles; Leroy, Eric; Pan, Yongxin

    2015-02-01

    Magnetotactic bacteria (MTB) are known to produce single-domain magnetite or greigite crystals within intracellular membrane organelles and to navigate along the Earth's magnetic field lines. MTB have been suggested as being one of the most ancient biomineralizing metabolisms on the Earth and they represent a fundamental model of intracellular biomineralization. Moreover, the determination of their specific crystallographic signature (e.g. structure and morphology) is essential for palaeoenvironmental and ancient-life studies. Yet, the mechanisms of MTB biomineralization remain poorly understood, although this process has been extensively studied in several cultured MTB strains in the Proteobacteria phylum. Here, we show a comprehensive transmission electron microscopy (TEM) study of magnetic and structural properties down to atomic scales on bullet-shaped magnetites produced by the uncultured strain MYR-1 belonging to the Nitrospirae phylum, a deeply branching phylogenetic MTB group. We observed a multiple-step crystal growth of MYR-1 magnetite: initial isotropic growth forming cubo-octahedral particles (less than approx. 40 nm), subsequent anisotropic growth and a systematic final elongation along [001] direction. During the crystal growth, one major {111} face is well developed and preserved at the larger basal end of the crystal. The basal {111} face appears to be terminated by a tetrahedral-octahedral-mixed iron surface, suggesting dimensional advantages for binding protein(s), which may template the crystallization of magnetite. This study offers new insights for understanding magnetite biomineralization within the Nitrospirae phylum. PMID:25566884

  19. Improving the coverage of the cyanobacterial phylum using diversity-driven genome sequencing

    PubMed Central

    Shih, Patrick M.; Wu, Dongying; Latifi, Amel; Axen, Seth D.; Fewer, David P.; Talla, Emmanuel; Calteau, Alexandra; Cai, Fei; Tandeau de Marsac, Nicole; Rippka, Rosmarie; Herdman, Michael; Sivonen, Kaarina; Coursin, Therese; Laurent, Thierry; Goodwin, Lynne; Nolan, Matt; Davenport, Karen W.; Han, Cliff S.; Rubin, Edward M.; Eisen, Jonathan A.; Woyke, Tanja; Gugger, Muriel; Kerfeld, Cheryl A.

    2013-01-01

    The cyanobacterial phylum encompasses oxygenic photosynthetic prokaryotes of a great breadth of morphologies and ecologies; they play key roles in global carbon and nitrogen cycles. The chloroplasts of all photosynthetic eukaryotes can trace their ancestry to cyanobacteria. Cyanobacteria also attract considerable interest as platforms for “green” biotechnology and biofuels. To explore the molecular basis of their different phenotypes and biochemical capabilities, we sequenced the genomes of 54 phylogenetically and phenotypically diverse cyanobacterial strains. Comparison of cyanobacterial genomes reveals the molecular basis for many aspects of cyanobacterial ecophysiological diversity, as well as the convergence of complex morphologies without the acquisition of novel proteins. This phylum-wide study highlights the benefits of diversity-driven genome sequencing, identifying more than 21,000 cyanobacterial proteins with no detectable similarity to known proteins, and foregrounds the diversity of light-harvesting proteins and gene clusters for secondary metabolite biosynthesis. Additionally, our results provide insight into the distribution of genes of cyanobacterial origin in eukaryotic nuclear genomes. Moreover, this study doubles both the amount and the phylogenetic diversity of cyanobacterial genome sequence data. Given the exponentially growing number of sequenced genomes, this diversity-driven study demonstrates the perspective gained by comparing disparate yet related genomes in a phylum-wide context and the insights that are gained from it. PMID:23277585

  20. Disseminated granulomas caused by an unidentified protozoan in sandhill cranes

    USGS Publications Warehouse

    Carpenter, J.W.; Spraker, T.R.; Gardiner, C.H.; Novilla, M.N.

    1979-01-01

    Oral granulomas were observed in 31 (33%) of 95 captive sandhill cranes (Grus canadensis) at the Patuxent Wildlife Research Center. Necropsy of six of the afflicted cranes revealed granulomatous nodules throughout many of their organ systems. Intracellular protozoan organisms morphologically resembling schizogonic stages were observed within the granulomas by light and electron microscopy. Sexual and asexual stages of coccidia were seen in sections of the intestines of 4 of 5 cranes examined microscopically, and Eimerian oocysts were seen in fecal flotation specimens from 3 of 4 birds.

  1. Protozoan Acanthamoeba polyphaga as a Potential Reservoir for Campylobacter jejuni

    PubMed Central

    Axelsson-Olsson, Diana; Waldenström, Jonas; Broman, Tina; Olsen, Björn; Holmberg, Martin

    2005-01-01

    We showed by a laboratory experiment that four different Campylobacter jejuni strains are able to infect the protozoan Acanthamoeba polyphaga. C. jejuni cells survived for longer periods when cocultured with amoebae than when grown in culture alone. The infecting C. jejuni cells aggregated in amoebic vacuoles, in which they were seen to be actively moving. Furthermore, a resuscitation of bacterial cultures that were previously negative in culturability tests was observed after reinoculation into fresh amoeba cultures. After spontaneous rupture of the amoebae, C. jejuni could be detected by microscopy and culturability tests. Our results indicate that amoebae may serve as a nonvertebrate reservoir for C. jejuni in the environment. PMID:15691957

  2. Disseminated granulomas caused by an unidentified protozoan in sandhill cranes.

    PubMed

    Carpenter, J W; Spraker, T R; Gardiner, C H; Novilla, M N

    1979-11-01

    Oral granulomas were observed in 31 (33%) of 95 captive sandhill cranes (Grus canadensis) at the Patuxent Wildlife Research Center. Necropsy of six of the afflicted cranes revealed granulomatous nodules throughout many of their organ systems. Intracellular protozoan organisms morphologically resembling schizogonic stages were observed within the granulomas by light and electron microscopy. Sexual and asexual stages of coccidia were seen in sections of the intestines of 4 of 5 cranes examined microscopically, and Eimerian oocysts were seen in fecal flotation specimens from 3 of 4 birds. PMID:521379

  3. Chromatin modifications, epigenetics, and how protozoan parasites regulate their lives

    PubMed Central

    Croken, Matthew M.; Nardelli, Sheila C.; Kim, Kami

    2012-01-01

    Chromatin structure plays a vital role in epigenetic regulation of protozoan parasite gene expression. Epigenetic gene regulation impacts parasite virulence, differentiation and cell cycle control. Recent work in many laboratories has elucidated the functions of histone modifying proteins that regulate parasite gene expression by chemical modification of constituent nucleosomes. A major focus of investigation has been characterizing post-translational modifications (PTM) of histones and identifying the enzymes that are responsible. Despite conserved features and specificity common to all eukaryotes, parasite enzymes involved in chromatin modification have unique functions that regulate unique aspects of parasite biology. PMID:22480826

  4. Complete Genome Sequence of the Bacterium Aalborg_AAW-1, Representing a Novel Family within the Candidate Phylum SR1.

    PubMed

    Dueholm, Morten Simonsen; Albertsen, Mads; Stokholm-Bjerregaard, Mikkel; McIlroy, Simon J; Karst, Søren M; Nielsen, Per Halkjær

    2015-01-01

    Here, we present the complete genome sequence of the candidate phylum SR1 bacterium Aalborg_AAW-1. Its 16S rRNA gene is only 85.5% similar to that of the closest relative, RAAC1_SR1, and the genome of Aalborg_AAW-1 consequently represents the first of a novel family within the candidate phylum SR1. PMID:26067967

  5. Complete Genome Sequence of the Bacterium Aalborg_AAW-1, Representing a Novel Family within the Candidate Phylum SR1

    PubMed Central

    Dueholm, Morten Simonsen; Albertsen, Mads; Stokholm-Bjerregaard, Mikkel; McIlroy, Simon J.; Karst, Søren M.

    2015-01-01

    Here, we present the complete genome sequence of the candidate phylum SR1 bacterium Aalborg_AAW-1. Its 16S rRNA gene is only 85.5% similar to that of the closest relative, RAAC1_SR1, and the genome of Aalborg_AAW-1 consequently represents the first of a novel family within the candidate phylum SR1. PMID:26067967

  6. A Detoxifying Oxygen Reductase in the Anaerobic Protozoan Entamoeba histolytica

    PubMed Central

    Vicente, João B.; Tran, Vy; Pinto, Liliana; Teixeira, Miguel

    2012-01-01

    We report the characterization of a bacterial-type oxygen reductase abundant in the cytoplasm of the anaerobic protozoan parasite Entamoeba histolytica. Upon host infection, E. histolytica is confronted with various oxygen tensions in the host intestine, as well as increased reactive oxygen and nitrogen species at the site of local tissue inflammation. Resistance to oxygen-derived stress thus plays an important role in the pathogenic potential of E. histolytica. The genome of E. histolytica has four genes that encode flavodiiron proteins, which are bacterial-type oxygen or nitric oxide reductases and were likely acquired by lateral gene transfer from prokaryotes. The EhFdp1 gene has higher expression in virulent than in nonvirulent Entamoeba strains and species, hinting that the response to oxidative stress may be one correlate of virulence potential. We demonstrate that EhFdp1 is abundantly expressed in the cytoplasm of E. histolytica and that the protein levels are markedly increased (up to ?5-fold) upon oxygen exposure. Additionally, we produced fully functional recombinant EhFdp1 and demonstrated that this enzyme is a specific and robust oxygen reductase but has poor nitric oxide reductase activity. This observation represents a new mechanism of oxygen resistance in the anaerobic protozoan pathogen E. histolytica. PMID:22798391

  7. Protozoan HSP90-heterocomplex: molecular interaction network and biological significance.

    PubMed

    Figueras, Maria J; Echeverria, Pablo C; Angel, Sergio O

    2014-05-01

    The HSP90 chaperone is a highly conserved protein from bacteria to higher eukaryotes. In eukaryotes, this chaperone participates in different large complexes, such as the HSP90 heterocomplex, which has important biological roles in cell homeostasis and differentiation. The HSP90-heterocomplex is also named the HSP90/HSP70 cycle because different co-chaperones (HIP, HSP40, HOP, p23, AHA1, immunophilins, PP5) participate in this complex by assembling sequentially, from the early to the mature complex. In this review, we analyze the conservation and relevance of HSP90 and the HSP90-heterocomplex in several protozoan parasites, with emphasis in Plasmodium spp., Toxoplasma spp., Leishmania spp. and Trypanosoma spp. In the last years, there has been an outburst of studies based on yeast two-hybrid methodology, co-immunoprecipitation-mass spectrometry and bioinformatics, which have generated a most comprehensive protein-protein interaction (PPI) network of HSP90 and its co-chaperones. This review analyzes the existing PPI networks of HSP90 and its co-chaperones of some protozoan parasites and discusses the usefulness of these powerful tools to analyze the biological role of the HSP90-heterocomplex in these parasites. The generation of a T. gondii HSP90 heterocomplex PPI network based on experimental data and a recent Plasmodium HSP90 heterocomplex PPI network are also included and discussed. As an example, the putative implication of nuclear transport and chromatin (histones and Sir2) as HSP90-heterocomplex interactors is here discussed. PMID:24694366

  8. Chitinase Dependent Control of Protozoan Cyst Burden in the Brain

    PubMed Central

    Nance, J. Philip; Vannella, Kevin M.; Worth, Danielle; David, Clément; Carter, David; Noor, Shahani; Hubeau, Cedric; Fitz, Lori; Lane, Thomas E.; Wynn, Thomas A.; Wilson, Emma H.

    2012-01-01

    Chronic infections represent a continuous battle between the host's immune system and pathogen replication. Many protozoan parasites have evolved a cyst lifecycle stage that provides it with increased protection from environmental degradation as well as endogenous host mechanisms of attack. In the case of Toxoplasma gondii, these cysts are predominantly found in the immune protected brain making clearance of the parasite more difficult and resulting in a lifelong infection. Currently, little is known about the nature of the immune response stimulated by the presence of these cysts or how they are able to propagate. Here we establish a novel chitinase-dependent mechanism of cyst control in the infected brain. Despite a dominant Th1 immune response during Toxoplasma infection there exists a population of alternatively activated macrophages (AAMØ) in the infected CNS. These cells are capable of cyst lysis via the production of AMCase as revealed by live imaging, and this chitinase is necessary for protective immunity within the CNS. These data demonstrate chitinase activity in the brain in response to a protozoan pathogen and provide a novel mechanism to facilitate cyst clearance during chronic infections. PMID:23209401

  9. Record of a gregarine (Apicomplexa: Neogregarinida) in the abdomen of the termite Coptotermes gestroi (Isoptera, Rhinotermitidae).

    PubMed

    Costa-Leonardo, Ana Maria; Casarin, Fabiana E; Constantini, Joice P

    2008-02-01

    Coptotermes gestroi is an exotic species of termite that is a pest of great economical importance in Brazil. This paper relates the occurrence of a coelomic gregarine (Apicomplexa: Neogregarinida) in the abdomen of the foraging workers recently collected from field colonies of this termite. The termite hosts presented large, white abdomens because they carried 1 up to 3 cysts of gregarines filled with numerous lemon-shaped spores. Earlier developmental stages of this gregarine were not observed in the scanning microscope preparations nor in the histological slides of the infected termites. However, the lemon-shaped spores suggest a parasite gregarine of Mattesia genus, family Lipotrophidae. PMID:17888946

  10. Quantitative Importance, Composition, and Seasonal Dynamics of Protozoan Communities in Polyhaline versus Freshwater Intertidal Sediments

    Microsoft Academic Search

    I. Hamels; K. Sabbe; K. Muylaert; W. Vyverman

    2004-01-01

    The quantitative importance and composition of protozoan communities was investigated in sandy and silty intertidal sediments of a polyhaline and a freshwater site in the Schelde estuary. Total biomass of the protozoans studied, integrated over the upper 4 cm of the sediment, ranged from 41 to 597 mg C m -2 and was in the same order of magnitude at

  11. Perkinsus marinus, a protozoan parasite of the Eastern oyster (Crassostrea virginica): effects of temperature on the uptake and

    E-print Network

    Hartley, Troy W.

    Perkinsus marinus, a protozoan parasite of the Eastern oyster (Crassostrea virginica): effects parasite, Perkinsus marinus, meront stage were tested at 10, 18, and 28 °C. Temperature significantly incorporation, lipid metabolism, Chromatography, Parasitic protozoan, Perkinsus marinus, Oyster, Crassostrea

  12. Evolutionary origin of the protozoan parasites histone-like proteins (HU).

    PubMed

    Arenas, Aylan Farid; Escobar, Andrés J Gutierrez; Gómez-Marin, Jorge Enrique

    2008-01-01

    The histone-like proteins (HU) belong to a family of DNA architectural proteins that stabilize nucleoprotein complexes. We found a putative HU protein (TgGlmHMM_3045) in Toxoplasma gondii genome that was homologous to the bacterial HU protein. This putative sequence was located in the scaffold TGG_995361 of the chromosome 10. The sequence included the prokaryotic bacterial histone-like domain, KFGSLGlRRRGERVARNPRT (ID number PS00045). HU protein sequences were also found in Plasmodium falciparum, Neospora caninum, Theileria parva and Theileria annulata. We found that the homology of the putative HU protein in Apicomplexa was greater with bacterial histone-like proteins than with eukaryotic histone proteins. The phylogenetic tree indicated that the putative HU protein genes were acquired in Apicomplexa by means of a secondary endosymbiotic event from red algae and later they were transferred from the apicoplast organelle to the nuclear genome. PMID:18430986

  13. Distribution and diversity of members of the bacterial phylum Fibrobacteres in environments where cellulose degradation occurs.

    PubMed

    Ransom-Jones, Emma; Jones, David L; Edwards, Arwyn; McDonald, James E

    2014-10-01

    The Fibrobacteres phylum contains two described species, Fibrobacter succinogenes and Fibrobacter intestinalis, both of which are prolific degraders of cellulosic plant biomass in the herbivore gut. However, recent 16S rRNA gene sequencing studies have identified novel Fibrobacteres in landfill sites, freshwater lakes and the termite hindgut, suggesting that members of the Fibrobacteres occupy a broader ecological range than previously appreciated. In this study, the ecology and diversity of Fibrobacteres was evaluated in 64 samples from contrasting environments where cellulose degradation occurred. Fibrobacters were detected in 23 of the 64 samples using Fibrobacter genus-specific 16S rRNA gene PCR, which provided their first targeted detection in marine and estuarine sediments, cryoconite from Arctic glaciers, as well as a broader range of environmental samples. To determine the phylogenetic diversity of the Fibrobacteres phylum, Fibrobacter-specific 16S rRNA gene clone libraries derived from 17 samples were sequenced (384 clones) and compared with all available Fibrobacteres sequences in the Ribosomal Database Project repository. Phylogenetic analysis revealed 63 lineages of Fibrobacteres (95% OTUs), with many representing as yet unclassified species. Of these, 24 OTUs were exclusively comprised of fibrobacters derived from environmental (non-gut) samples, 17 were exclusive to the mammalian gut, 15 to the termite hindgut, and 7 comprised both environmental and mammalian strains, thus establishing Fibrobacter spp. as indigenous members of microbial communities beyond the gut ecosystem. The data highlighted significant taxonomic and ecological diversity within the Fibrobacteres, a phylum circumscribed by potent cellulolytic activity, suggesting considerable functional importance in the conversion of lignocellulosic biomass in the biosphere. PMID:25154048

  14. Potential Conservation of Circadian Clock Proteins in the phylum Nematoda as Revealed by Bioinformatic Searches

    PubMed Central

    Romanowski, Andrés; Garavaglia, Matías Javier; Goya, María Eugenia; Ghiringhelli, Pablo Daniel; Golombek, Diego Andrés

    2014-01-01

    Although several circadian rhythms have been described in C. elegans, its molecular clock remains elusive. In this work we employed a novel bioinformatic approach, applying probabilistic methodologies, to search for circadian clock proteins of several of the best studied circadian model organisms of different taxa (Mus musculus, Drosophila melanogaster, Neurospora crassa, Arabidopsis thaliana and Synechoccocus elongatus) in the proteomes of C. elegans and other members of the phylum Nematoda. With this approach we found that the Nematoda contain proteins most related to the core and accessory proteins of the insect and mammalian clocks, which provide new insights into the nematode clock and the evolution of the circadian system. PMID:25396739

  15. Interferon in resistance to bacterial and protozoan infections

    NASA Technical Reports Server (NTRS)

    Sonnenfeld, Gerald; Gould, Cheryl L.; Kierszenbaum, Felipe; Degee, Antonie L. W.; Mansfield, John M.

    1986-01-01

    The effects of genetic differences in mouse strains on the modulation of protozoan infections by interferon (IFN) were investigated. In one set of experiments, three different strains of mice were injected with T. cruzi, and their sera were assayed at five time intervals for IFN titer. A greater quantity of IFN was produced by mouse strains that were susceptible to T. cruzi infection than by the more resistant strain. In another set of experiments, spleen cell cultures from inbred strains of mice were challenged with an antigen made from T.b. rhodesiense. The cells from mice resistant to infection, produced greater amounts of IFN-gamma than did cells from the susceptible mice. In a third set of experiments, it was found that mice injected with T.b. rhodesiense before being infected with a diabetogenic virus (EMC-D) were resistant to the effects of the virus and did not produce virus-specific antibody.

  16. Protozoan Parasites of Bivalve Molluscs: Literature Follows Culture

    PubMed Central

    Fernández Robledo, José A.; Vasta, Gerardo R.; Record, Nicholas R.

    2014-01-01

    Bivalve molluscs are key components of the estuarine environments as contributors to the trophic chain, and as filter –feeders, for maintaining ecosystem integrity. Further, clams, oysters, and scallops are commercially exploited around the world both as traditional local shellfisheries, and as intensive or semi–intensive farming systems. During the past decades, populations of those species deemed of environmental or commercial interest have been subject to close monitoring given the realization that these can suffer significant decline, sometimes irreversible, due to overharvesting, environmental pollution, or disease. Protozoans of the genera Perkinsus, Haplosporidium, Marteilia, and Bonamia are currently recognized as major threats for natural and farmed bivalve populations. Since their identification, however, the variable publication rates of research studies addressing these parasitic diseases do not always appear to reflect their highly significant environmental and economic impact. Here we analyzed the peer– reviewed literature since the initial description of these parasites with the goal of identifying potential milestone discoveries or achievements that may have driven the intensity of the research in subsequent years, and significantly increased publication rates. Our analysis revealed that after initial description of the parasite as the etiological agent of a given disease, there is a time lag before a maximal number of yearly publications are reached. This has already taken place for most of them and has been followed by a decrease in publication rates over the last decade (20– to 30– year lifetime in the literature). Autocorrelation analyses, however, suggested that advances in parasite purification and culture methodologies positively drive publication rates, most likely because they usually lead to novel molecular tools and resources, promoting mechanistic studies. Understanding these trends should help researchers in prioritizing research efforts for these and other protozoan parasites, together with their development as model systems for further basic and translational research in parasitic diseases. PMID:24955977

  17. From incipient to substantial: evolution of placentotrophy in a phylum of aquatic colonial invertebrates.

    PubMed

    Ostrovsky, Andrew N

    2013-05-01

    Matrotrophy has long been known in invertebrates, but it is still poorly understood and has never been reviewed. A striking example of matrotrophy (namely, placentotrophy) is provided by the Bryozoa, a medium-sized phylum of the aquatic colonial filter feeders. Here I report on an extensive anatomical study of placental analogues in 21 species of the bryozoan order Cheilostomata, offering the first review on matrotrophy among aquatic invertebrates. The first anatomical description of incipient placentotrophy in invertebrates is presented together with the evidence for multiple independent origins of placental analogues in this order. The combinations of contrasting oocytic types (macrolecithal or microlecithal) and various degrees of placental development and embryonic enlargement during incubation, found in different bryozoan species, are suggestive of a transitional series from the incipient to the substantial placentotrophy accompanied by an inverse change in oogenesis, a situation reminiscent of some vertebrates. It seems that matrotrophy could trigger the evolution of sexual zooidal polymorphism in some clades. The results of this study show that this phylum, with its wide variety of reproductive patterns, incubation devices, and types of the simple placenta-like systems, offers a promising model for studying parallel evolution of placentotrophy in particular, and matrotrophy in general. PMID:23617914

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

    PubMed

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

    2015-05-01

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

  19. Distribution and Evolution of Nitrogen Fixation Genes in the Phylum Bacteroidetes

    PubMed Central

    Inoue, Jun-ichi; Oshima, Kenshiro; Suda, Wataru; Sakamoto, Mitsuo; Iino, Takao; Noda, Satoko; Hongoh, Yuichi; Hattori, Masahira; Ohkuma, Moriya

    2015-01-01

    Diazotrophs had not previously been identified among bacterial species in the phylum Bacteroidetes until the rapid expansion of bacterial genome sequences, which revealed the presence of nitrogen fixation (nif) genes in this phylum. We herein determined the draft genome sequences of Bacteroides graminisolvens JCM 15093T and Geofilum rubicundum JCM 15548T. In addition to these and previously reported ‘Candidatus Azobacteroides pseudotrichonymphae’ and Paludibacter propionicigenes, an extensive survey of the genome sequences of diverse Bacteroidetes members revealed the presence of a set of nif genes (nifHDKENB) in strains of Dysgonomonas gadei, Dysgonomonas capnocytophagoides, Saccharicrinis fermentans, and Alkaliflexus imshenetskii. These eight species belonged to and were distributed sporadically within the order Bacteroidales. Acetylene reduction activity was detected in the five species examined, strongly suggesting their diazotrophic nature. Phylogenetic analyses showed monophyletic clustering of the six Nif protein sequences in the eight Bacteroidales species, implying that nitrogen fixation is ancestral to Bacteroidales and has been retained in these species, but lost in many other lineages. The identification of nif genes in Bacteroidales facilitates the prediction of the organismal origins of related sequences directly obtained from various environments. PMID:25736980

  20. Phylum-specific regulation of resistomycin production in a Streptomyces sp. via microbial coculture.

    PubMed

    Carlson, Skylar; Tanouye, Urszula; Omarsdottir, Sesselja; Murphy, Brian T

    2015-03-27

    Actinomycete genomes are encoded with immense potential to produce secondary metabolites, however standard laboratory culture experiments rarely provide the conditions under which associated biosynthetic pathways are expressed. Despite years of research attempting to access these pathways and aside from a few well-studied bacterial quorum sensing systems, little is known about the specificity of secondary metabolite regulation in bacteria, such as the conditions under which a bacterium produces an antibiotic and the extent to which it does so in recognition of a particular species in the immediate environment. In the current study, we observed that the cocultivation of a Streptomyces sp. (strain B033) with four pathogenic strains of the phylum Proteobacteria resulted in the production of the antibiotic resistomycin. After further coculture experiments, we determined that Proteobacteria induced the production of resistomycin in B033 at significantly higher rates (65%) than strains from the phyla Firmicutes (5.9%) and Actinobacteria (9.1%), supporting that the regulation of secondary metabolism in bacteria can be dependent on the species present in the immediate environment. These results suggest a lack of promiscuity of antibiotic biosynthetic pathway regulation and indicate that it is feasible to mine existing microbial strain libraries for antibiotics in a phylum-specific manner. PMID:25537064

  1. The First Complete Genome Sequence of the Class Fimbriimonadia in the Phylum Armatimonadetes

    PubMed Central

    Im, Wan-Taek; Wang, Sheng-Yue; Zhao, Guo-Ping; Zheng, Hua-Jun; Quan, Zhe-Xue

    2014-01-01

    In this study, we present the complete genome of Fimbriimonas ginsengisoli Gsoil 348T belonging to the class Fimbriimonadia of the phylum Armatimonadetes, formerly called as candidate phylum OP10. The complete genome contains a single circular chromosome of 5.23 Mb including a 45.5 kb prophage. Of the 4820 open reading frames (ORFs), 3,000 (62.2%) genes could be classified into Clusters of Orthologous Groups (COG) families. With the split of rRNA genes, strain Gsoil 348T had no typical 16S-23S-5S ribosomal RNA operon. In this genome, the GC skew inversion which was usually observed in archaea was found. The predicted gene functions suggest that the organism lacks the ability to synthesize histidine, and the TCA cycle is incomplete. Phylogenetic analyses based on ribosomal proteins indicated that strain Gsoil 348T represents a deeply branching lineage of sufficient divergence with other phyla, but also strongly involved in superphylum Terrabacteria. PMID:24967843

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

    PubMed Central

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

    2015-01-01

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

  3. Impact of water column acidification on protozoan bacterivory at the lake sediment-water interface

    SciTech Connect

    Tremaine, S.C.; Mills, A.L. (Univ. of Virginia, Charlottesville (USA))

    1991-03-01

    Although the impact of acidification on planktonic grazer food webs has been extensively studied, little is known about microbial food webs either in the water column or in the sediments. Protozoan-bacterium interactions were investigated in a chronically acidified (acid mine drainage) portion of a lake in Virginia. The authors determined the distribution, abundance, apparent specific grazing rate, and growth rate of protozoa over a pH range of 3.6 to 6.5. Protozoan abundance was lower at the most acidified site, while abundance, in general, was high compared with other systems. Specific grazing rates were uncorrelated with pH and ranged between 0.02 and 0.23 h{sup {minus}1}, values similar to those in unacidified systems. The protozoan community from an acidified station was not better adapted to low-pH conditions than a community from an unacidified site (multivariate analysis of variance on growth rates for each community incubated at pHs 4, 5, and 6). Both communities had significantly lower growth rates at pHs 4 and 5 than at pH 6. Reduced protozoan growth rates coupled with high grazing rates and relatively higher bacterial yields (ratio of bacterial-protozoan standing stock) at low pH indicate reduced net protozoan growth efficiency and a metabolic cost of acidification to the protozoan community. However, the presence of an abundant, neutrophilic protozoan community and high bacterial grazing rates indicates that acidification of Lake Anna has not inhibited the bacterium-protozoan link of the sediment microbial food web.

  4. Recent highlights in anti-protozoan drug development and resistance research

    PubMed Central

    Buckner, Frederick S.; Waters, Norman C.; Avery, Vicky M.

    2012-01-01

    This article summarizes the highlights of research presented in January, 2012, at the Keystone Symposium on “Drug Discovery for Protozoan Parasites” held in Santa Fe, New Mexico. This symposium which convenes approximately every 2 years provides a forum for leading investigators around the world to present data covering basic sciences to clinical trials relating to anti-protozoan drug development and drug resistance. Many talks focused on malaria, but other protozoan diseases receiving attention included African sleeping sickness, Chagas disease, leishmaniasis, cryptosporidiosis, and amoebiasis. The new research, most of it unpublished, provided insights into the latest developments in the field. PMID:24533285

  5. Besnoitia neotomofelis n. sp. (Protozoa: Apicomplexa) from the southern plains woodrat (Neotoma micropus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Certain species of the protozoan genus Besnoitia cause clinical disease in livestock and wildlife. In the present paper a new species, Besnoitia neotomofelis is described from the southern planes woodrat (Neotoma micropus). The parasite was detected by bioassay of woodrat tissues in out bred Swiss W...

  6. Gene Discovery by EST Sequencing in Toxoplasma gondii Reveals Sequences Restricted to the Apicomplexa

    Microsoft Academic Search

    James W. Ajioka; John C. Boothroyd; Brian P. Brunk; Adrian Hehl; Ledeana Hillier; Ian D. Manger; Marco Marra; G. Christian Overton; David S. Roos; Kiew-Lian Wan; Robert Waterston; L. David Sibley

    1998-01-01

    To accelerate gene discovery and facilitate genetic mapping in the protozoan parasite Toxoplasma gondii, we have generated >7000 new ESTs from the 58 ends of randomly selected tachyzoite cDNAs. Comparison of the ESTs with the existing gene databases identified possible functions for more than 500 new T. gondii genes by virtue of sequence motifs shared with conserved protein families, including

  7. The role of extracellular vesicles in Plasmodium and other protozoan parasites.

    PubMed

    Mantel, Pierre-Yves; Marti, Matthias

    2014-03-01

    Protozoan parasites and other microorganisms use various pathways to communicate within their own populations and to manipulate their outside environments, with the ultimate goal of balancing the rate of growth and transmission. In higher eukaryotes, including humans, circulating extracellular vesicles are increasingly recognized as key mediators of physiological and pathological processes. Recent evidence suggests that protozoan parasites, including those responsible for major human diseases such as malaria and Chagas disease, use similar machinery. Indeed, intracellular and extracellular protozoan parasites secrete extracellular vesicles to promote growth and induce transmission, to evade the host immune system, and to manipulate the microenvironment. In this review we will discuss the general pathways of extracellular vesicle biogenesis and their functions in protozoan infections. PMID:24406102

  8. Structure and mechanics of the spasmoneme, a biological spring within the protozoan Vorticella convallaria

    E-print Network

    France, Danielle Cook

    2007-01-01

    Molecular springs have recently emerged as the basis for the fastest and most powerful movements at the cellular level in biology. The spasmoneme of the protozoan, Vorticella convallaria, is a model molecular spring, relying ...

  9. Investigating the origins of triploblasty: `mesodermal' gene expression in a diploblastic animal, the sea anemone Nematostella vectensis (phylum, Cnidaria; class, Anthozoa)

    Microsoft Academic Search

    Mark Q. Martindale; Kevin Pang; John R. Finnerty

    2004-01-01

    Mesoderm played a crucial role in the radiation of the triploblastic Bilateria, permitting the evolution of larger and more complex body plans than in the diploblastic, non- bilaterian animals. The sea anemone Nematostella is a non- bilaterian animal, a member of the phylum Cnidaria. The phylum Cnidaria (sea anemones, corals, hydras and jellyfish) is the likely sister group of the

  10. Genome sequence of Victivallis vadensis ATCC BAA-548, an anaerobic bacterium from the phylum Lentisphaerae, isolated from the human gastro-intestinal tract

    SciTech Connect

    Van Passel, Mark W.J. [Wageningen University and Research Centre, The Netherlands; Kant, Ravi [University of Helsinki; Palva, Airi [University of Helsinki; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Davenport, Karen W. [Los Alamos National Laboratory (LANL); Sims, David [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Han, Cliff [Los Alamos National Laboratory (LANL); Larimer, Frank W [ORNL; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Richardson, Paul [U.S. Department of Energy, Joint Genome Institute; De Vos, Willem M. [Wageningen University and Research Centre, The Netherlands; Smidt, Hauke [Wageningen University and Research Centre, The Netherlands; Zoetendal, Erwin G. [Wageningen University and Research Centre, The Netherlands

    2011-01-01

    Victivallis vadensis ATCC BAA-548 represents the first cultured representative from the novel phylum Lentisphaerae, a deep-branching bacterial lineage. Few cultured bacteria from this phylum are known, and V. vadensis therefore represents an important organism for evolutionary studies. V. vadensis is a strictly anaerobic sugar-fermenting isolate from the human gastro-intestinal tract.

  11. Genome Sequence of Victivallis vadensis ATCC BAA-548, an Anaerobic Bacterium from the Phylum Lentisphaerae, Isolated from the Human Gastrointestinal Tract?

    PubMed Central

    van Passel, Mark W. J.; Kant, Ravi; Palva, Airi; Lucas, Susan; Copeland, Alex; Lapidus, Alla; Glavina del Rio, Tijana; Dalin, Eileen; Tice, Hope; Bruce, David; Goodwin, Lynne; Pitluck, Sam; Davenport, Karen Walston; Sims, David; Brettin, Thomas S.; Detter, John C.; Han, Shunsheng; Larimer, Frank W.; Land, Miriam L.; Hauser, Loren; Kyrpides, Nikolaos; Ovchinnikova, Galina; Richardson, P. Paul; de Vos, Willem M.; Smidt, Hauke; Zoetendal, Erwin G.

    2011-01-01

    Victivallis vadensis ATCC BAA-548 represents the first cultured representative from the novel phylum Lentisphaerae, a deep-branching bacterial lineage. Few cultured bacteria from this phylum are known, and V. vadensis therefore represents an important organism for evolutionary studies. V. vadensis is a strictly anaerobic sugar-fermenting isolate from the human gastrointestinal tract. PMID:21398537

  12. Pathogenesis of infection with Sarcocystis rauschorum (Apicomplexa) in experimentally infected varying lemmings (Dicrostonyx richardsoni).

    PubMed

    Stackhouse, L L; Cawthorn, R J; Brooks, R J

    1987-10-01

    This study describes the sequential formation of lesions associated with the endogenous development of Sarcocystis rauschorum (Apicomplexa: Sarcocystidae) in varying lemmings, Dicrostonyx richardsoni. Lethal doses of sporocysts (greater than 500) were orally administered to lemmings examined 1-6 days postinoculation (DPI) whereas sublethal doses were administered to lemmings examined subsequently. Transient necrosis and purulent inflammation, in association with precystic merogony, occurred in the liver by 4.5 DPI, peaked at 6 DPI and subsided beginning at 11 DPI with the liver returning to normal by 15 DPI. Cyst formation in skeletal and cardiac muscle was associated with purulent inflammation and sarcolemmal proliferation beginning at 9 DPI. These lesions persisted to 42 DPI. In addition, multifocal nonsuppurative meningoencephalitis was present in six of 11 infected lemmings examined between 11 and 15 DPI. PMID:3119871

  13. Attenuated reproduction of Strombus gigas by an Apicomplexa: Emeriidae-like parasite in the digestive gland.

    PubMed

    Baqueiro Cardenas, Erick; Montero, Jorge; Frenkiel, Liliane; Aldana Aranda, Dalila

    2012-07-01

    An intense and generalized sporozoan infection was detected in every population of the queen conch, Strombus gigas through the Caribbean. In this contribution we establish the relationship between occurrences of an Apicomplexa: Emeriidae-like organism and reproductive activity at San Andres archipelago, Colombia. Occurrence of the parasites was estimated counting the feeding stage Merozoites and cysts Sporozoites at 40× magnification. Nonmetric multidimensional scaling analysis (NMDS) was made to correlate the parasites stages abundance with frequency of the reproductive stages. Gametogenesis and spawning were always low coinciding with high numbers of Merozoites, a positive correlation was established between parasite abundance with reabsorption and undifferentiated stages, and negative correlation was observed between parasite abundance with maturity and spawning stages. The nonmetric multidimensional scaling (NMDS) shows that gametogenesis, maturity and spawning increase as the number of parasites decrease, factor that could be threatening reproduction of S. gigas through the Caribbean. PMID:22484565

  14. Protozoan predation and the turnover of soil organic carbon and nitrogen in the presence of plants

    Microsoft Academic Search

    P. J. Kuikman; A. G. Jansen; J. A. van Veen I; A. J. B. Zehnder

    1990-01-01

    The impact of protozoan grazing on the dynamics and mineralization of 14C- and 15N-labelled soil organic material was investigated in a microcosm experiment. Sterilized soil was planted with wheat and either inoculated with bacteria alone or with bacteria and protozoa or with bacteria and a 1:10 diluted protozoan inoculum. 14C-CO2 formation was continuously monitored. It served as an indicator of

  15. HIV Protease Inhibitors: Effect on the Opportunistic Protozoan Parasites.

    PubMed

    Alfonso, Yenisey; Monzote, Lianet

    2011-01-01

    The impact of highly active antiretroviral therapy (HAART) in the natural history of AIDS disease has been allowed to prolong the survival of people with HIV infection, particularly whose with increased HIV viral load. Additionally, the antiretroviral therapy could exert a certain degree of protection against parasitic diseases. A number of studies have been evidenced a decrease in the incidence of opportunistic parasitic infections in the era of HAART. Although these changes have been attributed to the restoration of cell-mediated immunity, induced by either non-nucleoside reverse transcriptase inhibitors or HIV protease inhibitors, in combination with at least two nucleoside reverse transcriptase inhibitors included in HAART, there are evidence that the control of these parasitic infections in HIV-positive persons under HAART, is also induced by the inhibition of the proteases of the parasites. This review focuses on the principal available data related with therapeutic HIV-protease inhibitors and their in vitro and in vivo effects on the opportunistic protozoan parasites. PMID:21629510

  16. Identifying Novel Cell Cycle Proteins in Apicomplexa Parasites through Co-Expression Decision Analysis

    PubMed Central

    Butler, Carrie L.; Lucas, Olivier; Wuchty, Stefan; Xue, Bin; Uversky, Vladimir N.; White, Michael

    2014-01-01

    Hypothetical proteins comprise roughly half of the predicted gene complement of Toxoplasma gondii and Plasmodium falciparum and represent the largest class of uniquely functioning proteins in these parasites. Following the idea that functional relationships can be informed by the timing of gene expression, we devised a strategy to identify the core set of apicomplexan cell division cycling genes with important roles in parasite division, which includes many uncharacterized proteins. We assembled an expanded list of orthologs from the T. gondii and P. falciparum genome sequences (2781 putative orthologs), compared their mRNA profiles during synchronous replication, and sorted the resulting set of dual cell cycle regulated orthologs (744 total) into protein pairs conserved across many eukaryotic families versus those unique to the Apicomplexa. The analysis identified more than 100 ortholog gene pairs with unknown function in T. gondii and P. falciparum that displayed co-conserved mRNA abundance, dynamics of cyclical expression and similar peak timing that spanned the complete division cycle in each parasite. The unknown cyclical mRNAs encoded a diverse set of proteins with a wide range of mass and showed a remarkable conservation in the internal organization of ordered versus disordered structural domains. A representative sample of cyclical unknown genes (16 total) was epitope tagged in T. gondii tachyzoites yielding the discovery of new protein constituents of the parasite inner membrane complex, key mitotic structures and invasion organelles. These results demonstrate the utility of using gene expression timing and dynamic profile to identify proteins with unique roles in Apicomplexa biology. PMID:24841368

  17. Brevifollis gellanilyticus gen. nov., sp. nov., a gellan-gum-degrading bacterium of the phylum Verrucomicrobia.

    PubMed

    Otsuka, Shigeto; Suenaga, Taku; Vu, Hoan Thi; Ueda, Hiroyuki; Yokota, Akira; Senoo, Keishi

    2013-08-01

    The taxonomic properties of strain DC2c-G4(T), a Gram-staining-negative, ovoid, gellan-gum-degrading bacterial isolate, were examined. Phylogenetic analysis based on 16S rRNA gene sequences identified this isolate as a member of the phylum Verrucomicrobia and closest to the genus Prosthecobacter. The 16S rRNA gene sequence similarities between this isolate and any of the type strains of species of the genus Prosthecobacter were less than 95 %. In addition, the absence of a single prostheca and the predominant menaquinone MK-7(H2) supported the differentiation of this isolate from the genus Prosthecobacter. Here, we propose Brevifollis gellanilyticus gen. nov., sp. nov. to accommodate the isolate. The type strain of the type species is DC2c-G4(T) (= NBRC 108608(T) = CIP 110457(T)). PMID:23416572

  18. From the Flavobacterium genus to the phylum Bacteroidetes: genomic analysis of dnd gene clusters.

    PubMed

    Barbier, Paul; Lunazzi, Aurélie; Fujiwara-Nagata, Erina; Avendaño-Herrera, Ruben; Bernardet, Jean-François; Touchon, Marie; Duchaud, Eric

    2013-11-01

    Phosphorothioate modification of DNA and the corresponding DNA degradation (Dnd) phenotype that occurs during gel electrophoresis are caused by dnd genes. Although widely distributed among Bacteria and Archaea, dnd genes have been found in only very few, taxonomically unrelated, bacterial species so far. Here, we report the presence of dnd genes and their associated Dnd phenotype in two Flavobacterium species. Comparison with dnd gene clusters previously described led us to report a noncanonical genetic organization and to identify a gene likely encoding a hybrid DndE protein. Hence, we showed that dnd genes are also present in members of the family Flavobacteriaceae, a bacterial group occurring in a variety of habitats with an interesting diversity of lifestyle. Two main types of genomic organization of dnd loci were uncovered probably denoting their spreading in the phylum Bacteroidetes via distinct genetic transfer events. PMID:23965156

  19. Genomic analysis of Chthonomonas calidirosea, the first sequenced isolate of the phylum Armatimonadetes

    PubMed Central

    Lee, Kevin C-Y; Morgan, Xochitl C; Dunfield, Peter F; Tamas, Ivica; McDonald, Ian R; Stott, Matthew B

    2014-01-01

    Most of the lineages of bacteria have remained unknown beyond environmental surveys using molecular markers. Until the recent characterisation of several strains, the phylum Armatimonadetes (formerly known as ‘candidate division OP10') was a dominant and globally-distributed lineage within this ‘uncultured majority'. Here we report the first Armatimonadetes genome from the thermophile Chthonomonas calidirosea T49T and its role as a saccharide scavenger in a geothermal steam-affected soil environment. Phylogenomic analysis indicates T49T to be related closely to the phylum Chloroflexi. The predicted genes encoding for carbohydrate transporters (27 carbohydrate ATP-binding cassette transporter-related genes) and carbohydrate-metabolising enzymes (including at least 55 putative enzymes with glycosyl hydrolase domains) within the 3.43?Mb genome help explain its ability to utilise a wide range of carbohydrates as well as its inability to break down extracellular cellulose. The presence of only a single class of branched amino acid transporter appears to be the causative step for the requirement of isoleucine for growth. The genome lacks many commonly conserved operons (for example, lac and trp). Potential causes for this, such as dispersion of functionally related genes via horizontal gene transfer from distant taxa or recent genome recombination, were rejected. Evidence suggests T49T relies on the relatively abundant ?-factors, instead of operonic organisation, as the primary means of transcriptional regulation. Examination of the genome with physiological data and environmental dynamics (including interspecific interactions) reveals ecological factors behind the apparent elusiveness of T49T to cultivation and, by extension, the remaining ‘uncultured majority' that have so far evaded conventional microbiological techniques. PMID:24477196

  20. “Endomicrobia”: Cytoplasmic Symbionts of Termite Gut Protozoa Form a Separate Phylum of Prokaryotes

    PubMed Central

    Stingl, Ulrich; Radek, Renate; Yang, Hong; Brune, Andreas

    2005-01-01

    Lignocellulose digestion by wood-feeding termites depends on the mutualistic interaction of unusual, flagellate protists located in their hindgut. Most of the flagellates harbor numerous prokaryotic endosymbionts of so-far-unknown identity and function. Using a full-cycle molecular approach, we show here that the endosymbionts of the larger gut flagellates of Reticulitermes santonensis belong to the so-called termite group 1 (TG-1) bacteria, a group of clones previously obtained exclusively from gut homogenates of Reticulitermes speratus that are only distantly related to other bacteria and are considered a novel bacterial phylum based on their 16S rRNA gene sequences. Fluorescence in situ hybridization with specifically designed oligonucleotide probes confirmed that TG-1 bacteria are indeed located within the flagellate cells and demonstrated that Trichonympha agilis (Hypermastigida) and Pyrsonympha vertens (Oxymonadida) harbor phylogenetically distinct populations of symbionts (<95% sequence similarity). Transmission electron microscopy revealed that the symbionts are small, spindle-shaped cells (0.6 ?m in length and 0.3 ?m in diameter) surrounded by two membranes and located within the cytoplasm of their hosts. The symbionts of the two flagellates are described as candidate species in the candidate genus “Endomicrobium.” Moreover, we provide evidence that the members of the TG-1 phylum, for which we propose the candidate name “Endomicrobia,” are phylogenetically extremely diverse and are present in and also restricted to the guts of all lower termites and wood-feeding cockroaches of the genus Cryptocercus, the only insects that are in an exclusive, obligately mutualistic association with such unique cellulose-fermenting protists. PMID:15746350

  1. "Endomicrobia": cytoplasmic symbionts of termite gut protozoa form a separate phylum of prokaryotes.

    PubMed

    Stingl, Ulrich; Radek, Renate; Yang, Hong; Brune, Andreas

    2005-03-01

    Lignocellulose digestion by wood-feeding termites depends on the mutualistic interaction of unusual, flagellate protists located in their hindgut. Most of the flagellates harbor numerous prokaryotic endosymbionts of so-far-unknown identity and function. Using a full-cycle molecular approach, we show here that the endosymbionts of the larger gut flagellates of Reticulitermes santonensis belong to the so-called termite group 1 (TG-1) bacteria, a group of clones previously obtained exclusively from gut homogenates of Reticulitermes speratus that are only distantly related to other bacteria and are considered a novel bacterial phylum based on their 16S rRNA gene sequences. Fluorescence in situ hybridization with specifically designed oligonucleotide probes confirmed that TG-1 bacteria are indeed located within the flagellate cells and demonstrated that Trichonympha agilis (Hypermastigida) and Pyrsonympha vertens (Oxymonadida) harbor phylogenetically distinct populations of symbionts (<95% sequence similarity). Transmission electron microscopy revealed that the symbionts are small, spindle-shaped cells (0.6 microm in length and 0.3 microm in diameter) surrounded by two membranes and located within the cytoplasm of their hosts. The symbionts of the two flagellates are described as candidate species in the candidate genus "Endomicrobium." Moreover, we provide evidence that the members of the TG-1 phylum, for which we propose the candidate name "Endomicrobia," are phylogenetically extremely diverse and are present in and also restricted to the guts of all lower termites and wood-feeding cockroaches of the genus Cryptocercus, the only insects that are in an exclusive, obligately mutualistic association with such unique cellulose-fermenting protists. PMID:15746350

  2. Behavioural resistance against a protozoan parasite in the monarch butterfly.

    PubMed

    Lefèvre, Thierry; Chiang, Allen; Kelavkar, Mangala; Li, Hui; Li, James; de Castillejo, Carlos Lopez Fernandez; Oliver, Lindsay; Potini, Yamini; Hunter, Mark D; de Roode, Jacobus C

    2012-01-01

    1. As parasites can dramatically reduce the fitness of their hosts, there should be strong selection for hosts to evolve and maintain defence mechanisms against their parasites. One way in which hosts may protect themselves against parasitism is through altered behaviours, but such defences have been much less studied than other forms of parasite resistance. 2. We studied whether monarch butterflies (Danaus plexippus L.) use altered behaviours to protect themselves and their offspring against the protozoan parasite Ophryocystis elektroscirrha (McLaughlin & Myers (1970), Journal of Protozoology, 17, p. 300). In particular, we studied whether (i) monarch larvae can avoid contact with infectious parasite spores; (ii) infected larvae preferentially consume therapeutic food plants when given a choice or increase the intake of such plants in the absence of choice; and (iii) infected female butterflies preferentially lay their eggs on medicinal plants that make their offspring less sick. 3. We found that monarch larvae were unable to avoid infectious parasite spores. Larvae were also not able to preferentially feed on therapeutic food plants or increase the ingestion of such plants. However, infected female butterflies preferentially laid their eggs on food plants that reduce parasite growth in their offspring. 4. Our results suggest that animals may use altered behaviours as a protection against parasites and that such behaviours may be limited to a single stage in the host-parasite life cycle. Our results also suggest that animals may use altered behaviours to protect their offspring instead of themselves. Thus, our study indicates that an inclusive fitness approach should be adopted to study behavioural defences against parasites. PMID:21939438

  3. Sequencing of the smallest Apicomplexan genome from the human pathogen Babesia microti†

    PubMed Central

    Cornillot, Emmanuel; Hadj-Kaddour, Kamel; Dassouli, Amina; Noel, Benjamin; Ranwez, Vincent; Vacherie, Benoît; Augagneur, Yoann; Brès, Virginie; Duclos, Aurelie; Randazzo, Sylvie; Carcy, Bernard; Debierre-Grockiego, Françoise; Delbecq, Stéphane; Moubri-Ménage, Karina; Shams-Eldin, Hosam; Usmani-Brown, Sahar; Bringaud, Frédéric; Wincker, Patrick; Vivarès, Christian P.; Schwarz, Ralph T.; Schetters, Theo P.; Krause, Peter J.; Gorenflot, André; Berry, Vincent; Barbe, Valérie; Ben Mamoun, Choukri

    2012-01-01

    We have sequenced the genome of the emerging human pathogen Babesia microti and compared it with that of other protozoa. B. microti has the smallest nuclear genome among all Apicomplexan parasites sequenced to date with three chromosomes encoding ?3500 polypeptides, several of which are species specific. Genome-wide phylogenetic analyses indicate that B. microti is significantly distant from all species of Babesidae and Theileridae and defines a new clade in the phylum Apicomplexa. Furthermore, unlike all other Apicomplexa, its mitochondrial genome is circular. Genome-scale reconstruction of functional networks revealed that B. microti has the minimal metabolic requirement for intraerythrocytic protozoan parasitism. B. microti multigene families differ from those of other protozoa in both the copy number and organization. Two lateral transfer events with significant metabolic implications occurred during the evolution of this parasite. The genomic sequencing of B. microti identified several targets suitable for the development of diagnostic assays and novel therapies for human babesiosis. PMID:22833609

  4. Protozoan grazing on bacteria at the sediment-water interface of an acidified lake

    SciTech Connect

    Tremaine, S.C.

    1988-01-01

    Protozoan grazing on bacteria has been hypothesized to link the detrital and grazer food chains in aquatic ecosystems. The current study of protozoan bacterivory, evaluated methods, quantified bacterivory, and evaluated the role of protozoa at the sediment-water interface of an acidified lake ecosystem, Lake Anna, Virginia. Three limnetic methods for determining protozoan bacterivory were tested for applicability at the sediment-water interface. The eucaryote inhibitor, cycloheximide, was found unsatisfactory because it did not uniformly inhibit growth of target eucaryotes, and because it inhibited non-target anaerobic procaryotes. The filtration method was found to have limited application in sediment systems due to filtrational loss of particle-associated bacteria. The dilution method was tested for violations of its critical assumptions: bacterial growth is exponential; grazing mortality is proportional to the dilution factor; and bacterial growth rates are unaltered under experimental conditions. These assumptions were found not to be violated, and this method was used in subsequent grazing experiments. Carbon loading to the acidified arm of Lake Anna was 41 {times} 10{sup 6} g C {times} y{sup {minus}1}. This appears to be adequate carbon loading to support bacterial production and, in turn, protozoan bacterivory and production. Though there is no direct evidence that zooplankton graze on protozoa in this system, however, there is sufficient protozoan production to support an additional trophic level.

  5. Quantitative importance, composition, and seasonal dynamics of protozoan communities in polyhaline versus freshwater intertidal sediments.

    PubMed

    Hamels, I; Sabbe, K; Muylaert, K; Vyverman, W

    2004-01-01

    The quantitative importance and composition of protozoan communities was investigated in sandy and silty intertidal sediments of a polyhaline and a freshwater site in the Schelde estuary. Total biomass of the protozoans studied, integrated over the upper 4 cm of the sediment, ranged from 41 to 597 mg C m(-2) and was in the same order of magnitude at the polyhaline and the freshwater intertidal site. Nanoheterotrophs were the dominant protozoans, in terms of both abundance and biomass. Ciliate abundances appeared to be largely determined by physical constraints, namely, the amount of interstitial space and hydrodynamic disturbances. It remains unclear which factors control nanoheterotrophic abundances and biomasses, which showed comparatively little seasonal and between-site fluctuations. Salinity differences were clearly reflected in the protozoan community composition. The dominant role of sessile ciliates is a unique feature of sediments in the freshwater tidal reaches, which can be attributed to the dynamic nature of sedimentation and resuspension processes associated with the maximum turbidity zone. Based on biomass ratios and estimated weight-specific metabolic rates, protozoa possibly accounted for approximately 29 to 96% of the estimated combined metabolic rate of protozoan and metazoan consumers at our sampling stations in late spring/early autumn. The contribution of protozoa to this combined metabolic rate was higher at the sandy than at the silty stations and was mainly accounted for by the nanoheterotrophs. These data emphasize the potential importance of small protozoa in sediments and suggest that protozoa are important components of benthic food webs. PMID:15259266

  6. Humanized HLA-DR4 Mice Fed with the Protozoan Pathogen of Oysters Perkinsus Marinus (Dermo) Do Not Develop Noticeable Pathology but Elicit Systemic Immunity

    PubMed Central

    Kleschenko, Yuliya; Pow-Sang, Luis; Brumeanu, Teodor D.; Villasante, Eileen Franke; Vasta, Gerardo R.; Fernández-Robledo, José-Antonio; Casares, Sofia

    2014-01-01

    Perkinsus marinus (Phylum Perkinsozoa) is a marine protozoan parasite responsible for “Dermo” disease in oysters, which has caused extensive damage to the shellfish industry and estuarine environment. The infection prevalence has been estimated in some areas to be as high as 100%, often causing death of infected oysters within 1–2 years post-infection. Human consumption of the parasites via infected oysters is thus likely to occur, but to our knowledge the effect of oral consumption of P. marinus has not been investigated in humans or other mammals. To address the question we used humanized mice expressing HLA-DR4 molecules and lacking expression of mouse MHC-class II molecules (DR4.EA0) in such a way that CD4 T cell responses are solely restricted by the human HLA-DR4 molecule. The DR4.EA0 mice did not develop diarrhea or any detectable pathology in the gastrointestinal tract or lungs following single or repeated feedings with live P. marinus parasites. Furthermore, lymphocyte populations in the gut associated lymphoid tissue and spleen were unaltered in the parasite-fed mice ruling out local or systemic inflammation. Notably, naïve DR4.EA0 mice had antibodies (IgM and IgG) reacting against P. marinus parasites whereas parasite specific T cell responses were undetectable. Feeding with P. marinus boosted the antibody responses and stimulated specific cellular (IFN?) immunity to the oyster parasite. Our data indicate the ability of P. marinus parasites to induce systemic immunity in DR4.EA0 mice without causing noticeable pathology, and support rationale grounds for using genetically engineered P. marinus as a new oral vaccine platform to induce systemic immunity against infectious agents. PMID:24498105

  7. Bacteria of the Candidate Phylum TM7 are Prevalent in Acidophilic Nitrifying Sequencing-Batch Reactors

    PubMed Central

    Hanada, Akiko; Kurogi, Takashi; Giang, Nguyen Minh; Yamada, Takeshi; Kamimoto, Yuki; Kiso, Yoshiaki; Hiraishi, Akira

    2014-01-01

    Laboratory-scale acidophilic nitrifying sequencing-batch reactors (ANSBRs) were constructed by seeding with sewage-activated sludge and cultivating with ammonium-containing acidic mineral medium (pH 4.0) with or without a trace amount of yeast extract. In every batch cycle, the pH varied between 2.7 and 4.0, and ammonium was completely converted to nitrate. Attempts to detect nitrifying functional genes in the fully acclimated ANSBRs by PCR with previously designed primers mostly gave negative results. 16S rRNA gene-targeted PCR and a subsequent denaturating gradient gel electrophoresis analysis revealed that a marked change occurred in the bacterial community during the overall period of operation, in which members of the candidate phylum TM7 and the class Gammaproteobacteria became predominant at the fully acclimated stage. This result was fully supported by a 16S rRNA gene clone library analysis, as the major phylogenetic groups of clones detected (>5% of the total) were TM7 (33%), Gammaproteobacteria (37%), Actinobacteria (10%), and Alphaproteobacteria (8%). Fluorescence in situ hybridization with specific probes also demonstrated the prevalence of TM7 bacteria and Gammaproteobacteria. These results suggest that previously unknown nitrifying microorganisms may play a major role in ANSBRs; however, the ecophysiological significance of the TM7 bacteria predominating in this process remains unclear. PMID:25241805

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

    PubMed

    Gibson, Amanda Kyle; Fuentes, Jesualdo Arturo

    2015-02-01

    Sexual outcrossing is costly relative to selfing and asexuality, yet it is ubiquitous in nature, a paradox that has long puzzled evolutionary biologists. The Red Queen Hypothesis argues that outcrossing is maintained by antagonistic interactions between host and parasites. Most tests of this hypothesis focus on the maintenance of outcrossing in hosts. The Red Queen makes an additional prediction that parasitic taxa are more likely to be outcrossing than their free-living relatives. We test this prediction in the diverse Nematode phylum using phylogenetic comparative methods to evaluate trait correlations. In support of the Red Queen, we demonstrate a significant correlation between parasitism and outcrossing in this clade. We find that this correlation is driven by animal parasites, for which outcrossing is significantly enriched relative to both free-living and plant parasitic taxa. Finally, we test hypotheses for the evolutionary history underlying the correlation of outcrossing and animal parasitism. Our results demonstrate that selfing and asexuality are significantly less likely to arise on parasitic lineages than on free-living ones. The findings of this study are consistent with the Red Queen Hypothesis. Moreover, they suggest that the maintenance of genetic variation is an important factor in the persistence of parasitic lineages. PMID:25403727

  9. Sunxiuqinia rutila sp. nov., a new member of the phylum Bacteroidetes isolated from marine sediment.

    PubMed

    Yoon, Jaewoo; Kasai, Hiroaki

    2014-01-01

    A Gram-negative, facultatively anaerobic, pale-red-pigmented, non-motile, rod-shaped strain designated HG677(T) was isolated from a sediment sample collected at Nagasuka Fishery Harbor in Miyagi Prefecture, Japan. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the novel isolate was affiliated with the phylum Bacteroidetes and that it showed highest sequence similarity (97.2%) to Sunxiuqinia elliptica DQHS4(T). The hybridization values for DNA-DNA relatedness between the strains of HG677(T) and Sunxiuqinia elliptica DQHS4(T) were lower than 70%, which is accepted as the phylogenetic definition of a novel species. The DNA G+C content of strain HG677(T) was 47.5 mol%; MK-7 was the major menaquinone; and the presence of iso-C15?0 and iso-C17?0 3-OH as the major cellular fatty acids supported the identification of the novel isolate as a member of the genus Sunxiuqinia. A complex polar lipid profile was present consisting of phosphatidylethanolamine, unidentified phospholipids, an unidentified aminolipid and four unidentified lipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel species for which the name Sunxiuqinia rutila sp. nov. is proposed. The type strain of Sunxiuqinia rutila is HG677(T) (= KCTC 32434(T) = NBRC 109919(T)). PMID:24646759

  10. Culture-independent characterization of a novel, uncultivated magnetotactic member of the Nitrospirae phylum.

    PubMed

    Lefèvre, Christopher T; Frankel, Richard B; Abreu, Fernanda; Lins, Ulysses; Bazylinski, Dennis A

    2011-02-01

    A magnetotactic bacterium, designated strain LO-1, of the Nitrospirae phylum was detected and concentrated from a number of freshwater and slightly brackish aquatic environments in southern Nevada. The closest phylogenetic relative to LO-1 is Candidatus Magnetobacterium bavaricum based on a 91.2% identity in their 16S rRNA gene sequence. Chemical and cell profiles of a microcosm containing water and sediment show that cells of strain LO-1 are confined to the oxic-anoxic interface and the upper regions of the anaerobic zone which in this case, occurred in the sediment. This microorganism is relatively large, ovoid in morphology and usually biomineralizes three braid-like bundles of multiple chains of bullet-shaped magnetosomes that appeared to be enclosed in a magnetosome membrane. Cells of LO-1 had an unusual three-layered unit membrane cell wall and contained several types of inclusions, some of which are sulfur-rich. Strain LO-1 is motile by means of a single bundle of sheathed flagella and exhibits the typical 'wobbling' motility and helical swimming ('flight') path of the magnetotactic cocci. This study and reports from others suggest that LO-1-like organisms are widespread in sediments of freshwater to brackish natural aquatic environments. PMID:20977572

  11. Characterization of taxonomically restricted genes in a phylum-restricted cell type

    PubMed Central

    Milde, Sabine; Hemmrich, Georg; Anton-Erxleben, Friederike; Khalturin, Konstantin; Wittlieb, Jörg; Bosch, Thomas CG

    2009-01-01

    Background Despite decades of research, the molecular mechanisms responsible for the evolution of morphological diversity remain poorly understood. While current models assume that species-specific morphologies are governed by differential use of conserved genetic regulatory circuits, it is debated whether non-conserved taxonomically restricted genes are also involved in making taxonomically relevant structures. The genomic resources available in Hydra, a member of the early branching animal phylum Cnidaria, provide a unique opportunity to study the molecular evolution of morphological novelties such as the nematocyte, a cell type characteristic of, and unique to, Cnidaria. Results We have identified nematocyte-specific genes by suppression subtractive hybridization and find that a considerable portion has no homologues to any sequences in animals outside Hydra. By analyzing the transcripts of these taxonomically restricted genes and mining of the Hydra magnipapillata genome, we find unexpected complexity in gene structure and transcript processing. Transgenic Hydra expressing the green fluorescent protein reporter under control of one of the taxonomically restricted gene promoters recapitulate faithfully the described expression pattern, indicating that promoters of taxonomically restricted genes contain all elements essential for spatial and temporal control mechanisms. Surprisingly, phylogenetic footprinting of this promoter did not reveal any conserved cis-regulatory elements. Conclusions Our findings suggest that taxonomically restricted genes are involved in the evolution of morphological novelties such as the cnidarian nematocyte. The transcriptional regulatory network controlling taxonomically restricted gene expression may contain not yet characterized transcription factors or cis-regulatory elements. PMID:19161630

  12. First genomic insights into members of a candidate bacterial phylum responsible for wastewater bulking

    PubMed Central

    Ohashi, Akiko; Parks, Donovan H.; Yamauchi, Toshihiro; Tyson, Gene W.

    2015-01-01

    Filamentous cells belonging to the candidate bacterial phylum KSB3 were previously identified as the causative agent of fatal filament overgrowth (bulking) in a high-rate industrial anaerobic wastewater treatment bioreactor. Here, we obtained near complete genomes from two KSB3 populations in the bioreactor, including the dominant bulking filament, using differential coverage binning of metagenomic data. Fluorescence in situ hybridization with 16S rRNA-targeted probes specific for the two populations confirmed that both are filamentous organisms. Genome-based metabolic reconstruction and microscopic observation of the KSB3 filaments in the presence of sugar gradients indicate that both filament types are Gram-negative, strictly anaerobic fermenters capable of non-flagellar based gliding motility, and have a strikingly large number of sensory and response regulator genes. We propose that the KSB3 filaments are highly sensitive to their surroundings and that cellular processes, including those causing bulking, are controlled by external stimuli. The obtained genomes lay the foundation for a more detailed understanding of environmental cues used by KSB3 filaments, which may lead to more robust treatment options to prevent bulking. PMID:25650158

  13. A Review of Recent Patents on the Protozoan Parasite HSP90 as a Drug Target

    PubMed Central

    Angel, Sergio O; Matrajt, Mariana; Echeverria, Pablo C

    2013-01-01

    Diseases caused by protozoan parasites are still an important health problem. These parasites can cause a wide spectrum of diseases, some of which are severe and have high morbidity or mortality if untreated. Since they are still uncontrolled, it is important to find novel drug targets and develop new therapies to decrease their remarkable social and economic impact on human societies. In the past years, human HSP90 has become an interesting drug target that has led to a large number of investigations both at state organizations and pharmaceutical companies, followed by clinical trials. The finding that HSP90 has important biological roles in some protozoan parasites like Plasmodium spp, Toxoplasma gondii and trypanosomatids has allowed the expansion of the results obtained in human cancer to these infections. This review summarizes the latest important findings showing protozoan HSP90 as a drug target and presents three patents targeting T. gondii, P. falciparum and trypanosomatids HSP90. PMID:23002958

  14. Phylogenetic Relationships within the Class Anthozoa (Phylum Cnidaria) Based on Nuclear 18S rDNA Sequences

    Microsoft Academic Search

    Ewann A. Berntson; Scott C. France; Lauren S. Mullineaux

    1999-01-01

    Taxonomic relationships within the corals and anemones (Phylum Cnidaria: Class Anthozoa) are based upon few morphological characters. The significance of any given character is debatable, and there is little fossil record available for deriving evolutionary relationships. We analyzed complete 18S ribosomal sequences to examine subclass-level and ordinal-level organization within the Anthozoa. We suggest that the Subclass Ceriantipatharia is not an

  15. DETECTION OF PROTOZOAN PARASITES IN SOURCE AND FINISHED WATER - 3RD EDITION ASM'S METHODS IN ENVIRONMENTAL MICROBIOLOGY

    EPA Science Inventory

    Protozoans are eukaryotic organisms which can live either a free-living or parasitic existence. Some free-living forms, under the right conditions, can become opportunistic parasites. Enteric pathogenic protozoans, like Giardia and Cryptosporidium, which are now known to be tra...

  16. Two new species of Caryospora Léger, 1904 (Apicomplexa, Eimeriidae) from accipitrid raptors.

    PubMed

    Volf, J; Koudela, B; Modrý, D

    2000-05-01

    Two new species of Coccidia (Apicomplexa: Eimeriidae) are described from European accipitrid raptors (Falconiformes: Accipitridae). Oöcysts of Carvospora aquilae n. sp. found in faeces of the gold eagle Aquila chrysaetos are subspherical to broad ellipsoidal and measure 43 (40-49) x 37.5 (34-39) microm. Polar granule, oöcyst residuum and micropyle are absent. Each oöcyst contains one spherical to subspherical slightly polygonal sporocyst measuring 23.8 (23-25) x 23.3 (22-25) microm. Stieda and substieda bodies are absent. The sporocyst residuum is composed of numerous small granules less than 0.5 microm in diameter dispersed randomly among the sporozoites. Sporulated oöcysts of Carvospora circi n. sp. from faeces of the marsh harrier Circus aeruginosus are widely oval, measuring 24.5 (23-25) x 21.8 (21-24) microm. A polar granule, oöcyst residuum and micropyle are absent. Each oöcyst contains one spherical to subspherical sporocyst measuring 16.2 (15-17) x 15.6 (15-17) microm. A compact granular, spherical to subspherical sporocyst residuum, 10.4 (10-11) x 8.5 (7-9), was present in 76% of measured sporocysts. In 24% of sporocysts the granules of sporocyst residuum were scattered among the sporozoites. PMID:10803432

  17. Full-parasites: database of full-length cDNAs of apicomplexa parasites, 2010 update

    PubMed Central

    Tuda, Josef; Mongan, Arthur E.; Tolba, Mohammed E. M.; Imada, Mihoko; Yamagishi, Junya; Xuan, Xuenan; Wakaguri, Hiroyuki; Sugano, Sumio; Sugimoto, Chihiro; Suzuki, Yutaka

    2011-01-01

    Full-Parasites (http://fullmal.hgc.jp/) is a transcriptome database of apicomplexa parasites, which include Plasmodium and Toxoplasma species. The latest version of Full-Parasites contains a total of 105?786 EST sequences from 12 parasites, of which 5925 full-length cDNAs have been completely sequenced. Full-Parasites also contain more than 30 million transcription start sites (TSS) for Plasmodium falciparum (Pf) and Toxoplasma gondii (Tg), which were identified using our novel oligo-capping-based protocol. Various types of cDNA data resources were interconnected with our original database functionalities. Specifically, in this update, we have included two unique RNA-Seq data sets consisting of 730 million mapped RNA-Seq tags. One is a dataset of 16 time-lapse experiments of cultured bradyzoite differentiation for Tg. The other dataset includes 31 clinical samples of Pf. Parasite RNA was extracted together with host human RNA, and the extracted mixed RNA was used for RNA sequencing, with the expectation that gene expression information from the host and parasite would be simultaneously represented. By providing the largest unique full-length cDNA and dynamic transcriptome data, Full-Parasites is useful for understanding host–parasite interactions and will help to eventually elucidate how monophyletic organisms have evolved to become parasites by adopting complex life cycles. PMID:21051343

  18. Occurrence of Apicomplexa-like structures in the digestive gland of Strombus gigas throughout the Caribbean.

    PubMed

    Aranda, Dalila Aldana; Frenkiel, Liliane; Brulé, Thierry; Montero, Jorge; Cárdenas, Erick Baqueiro

    2011-02-01

    The queen conch, Strombus gigas, is a marine resource of ecological and economical importance in the Caribbean region. Given its importance in this region, and the critical status of most populations, the reproductive biology of this species has been studied to support management decisions. It was from these studies that a generalized sporozoan infection was detected. This study describes the geographic distribution of a coccidian (Apicomplexa) parasite infecting the digestive gland of S. gigas throughout the Caribbean. The parasite was present in every location sampled. Based on histological analysis, the parasites from all locations are similar and appear to complete their life cycle within the digestive gland. The highest occurrence of the parasites was registered in samples from Puerto Rico (54 parasites per field) and Martinique (45 parasites per field). The lowest incidence was registered on the Mexican coast of Yucatan peninsula, at Alacranes and Chinchorro with 17 parasites per field. Data showed significant differences among sites (Kruskal Wallis H=106.957; p ? 0.05). The abundance of parasites found in the digestive ducts and in the faeces suggests the liberation of parasites to the environment. A gradual decrease in abundance was found from East to West of the Caribbean sea. PMID:20851703

  19. The red-tailed hawk, Buteo jamaicensis, a native definitive host of Frenkelia microti (Apicomplexa) in North America.

    PubMed

    Upton, S J; McKown, R D

    1992-01-01

    Oral inoculation of prairie voles, Microtus ochrogaster, with coccidian sporocysts isolated from the feces of a red-tailed hawk, Buteo jamaicensis, in Kansas, USA, resulted in formation of Frenkelia microti (Apicomplexa: Sarcocystidae) tissue cysts in the brains of the voles. Five additional isolates of morphologically similar sporocysts collected from red-tailed hawks or other Buteo spp. in Kansas failed to result in detectable infections in rodents. These results are the first to verify that red-tailed hawks are natural definitive host in North America for F. microti. PMID:1548806

  20. Bull. U. S.F. C.1893. On a Parasitic Protozoan. (To face page 173.) PLATE11, REPORT ON A PARASITIC PROTOZOANOBSERVED ON FISH IN THEAQUARIUM.

    E-print Network

    Bull. U. S.F. C.1893. On a Parasitic Protozoan. (To face page 173.) PLATE11, a .t: k #12;REPORT discovered to be seriously infested with a protozoan parasite. The geueral pressure of aquarium operations

  1. Eimeria Species (Apicomplexa: Eimeriidae) from Arctic Ground Squirrels (Spermophilus parryii ) and Red Squirrels (Tamiasciurus hudsonicus) in Alaska and in Siberia, Russia

    Microsoft Academic Search

    Robert S. Seville; Clint E. Oliver; Andrew J. Lynch; Michelle C. Bryant; Donald W. Duszynski

    2005-01-01

    Fecal samples from arctic ground squirrels (Spermophilus parryii) collected in Alaska (n = 90) and Russia (n = 46) and from red squirrels (Tamiasciurus hudsonicus) in Alaska (n = 35) were examined for the presence of Eimeria spp. (Apicomplexa: Eimeriidae). Four species were recovered from arctic ground squirrels, including Eimeria callospermophili (prevalence = 18%), Eimeria cynomysis (23.5%), Eimeria lateralis (19%),

  2. Trichurispora wellgundis n. g., n. sp. (Apicomplexa: Eugregarinida: Hirmocystidae) Parasitizing Adult Water Scavenger Beetles, Tropisternus collaris (Coleoptera: Hydrophilidae) in the Texas Big Thicket

    Microsoft Academic Search

    R. E. Clopton; T. J. Cook; J. L. Cook

    2008-01-01

    Trichurispora wellgundis n. g., n. sp. (Apicomplexa: Eugregarinida: Hirmocystidae) is described from the adults of the water scavenger beetle Tropisternus collaris (Coleoptera: Hydrophilidae) collected from B A Steinhagen Lake in the Cherokee Unit of the Big Thicket National Preserve, Tyler County, Texas, U.S.A. Trichurispora is distinguished from known genera of Hirmocystidae by a distinct ''trichurisiform'' oocyst that is hesperidiform in

  3. In Silico Analysis of the Metabolic Potential and Niche Specialization of Candidate Phylum "Latescibacteria" (WS3).

    PubMed

    Youssef, Noha H; Farag, Ibrahim F; Rinke, Christian; Hallam, Steven J; Woyke, Tanja; Elshahed, Mostafa S

    2015-01-01

    The "Latescibacteria" (formerly WS3), member of the Fibrobacteres-Chlorobi-Bacteroidetes (FCB) superphylum, represents a ubiquitous candidate phylum found in terrestrial, aquatic, and marine ecosystems. Recently, single-cell amplified genomes (SAGs) representing the "Latescibacteria" were obtained from the anoxic monimolimnion layers of Sakinaw Lake (British Columbia, Canada), and anoxic sediments of a coastal lagoon (Etoliko lagoon, Western Greece). Here, we present a detailed in-silico analysis of the four SAGs to gain some insights on their metabolic potential and apparent ecological roles. Metabolic reconstruction suggests an anaerobic fermentative mode of metabolism, as well as the capability to degrade multiple polysaccharides and glycoproteins that represent integral components of green (Charophyta and Chlorophyta) and brown (Phaeophycaea) algae cell walls (pectin, alginate, ulvan, fucan, hydroxyproline-rich glycoproteins), storage molecules (starch and trehalose), and extracellular polymeric substances (EPSs). The analyzed SAGs also encode dedicated transporters for the uptake of produced sugars and amino acids/oligopeptides, as well as an extensive machinery for the catabolism of all transported sugars, including the production of a bacterial microcompartment (BMC) to sequester propionaldehyde, a toxic intermediate produced during fucose and rhamnose metabolism. Finally, genes for the formation of gas vesicles, flagella, type IV pili, and oxidative stress response were found, features that could aid in cellular association with algal detritus. Collectively, these results indicate that the analyzed "Latescibacteria" mediate the turnover of multiple complex organic polymers of algal origin that reach deeper anoxic/microoxic habitats in lakes and lagoons. The implications of such process on our understanding of niche specialization in microbial communities mediating organic carbon turnover in stratified water bodies are discussed. PMID:26039074

  4. Nitrification expanded: discovery, physiology and genomics of a nitrite-oxidizing bacterium from the phylum Chloroflexi

    PubMed Central

    Sorokin, Dimitry Y; Lücker, Sebastian; Vejmelkova, Dana; Kostrikina, Nadezhda A; Kleerebezem, Robbert; Rijpstra, W Irene C; Damsté, Jaap S Sinninghe; Le Paslier, Denis; Muyzer, Gerard; Wagner, Michael; van Loosdrecht, Mark C M; Daims, Holger

    2012-01-01

    Nitrite-oxidizing bacteria (NOB) catalyze the second step of nitrification, a major process of the biogeochemical nitrogen cycle, but the recognized diversity of this guild is surprisingly low and only two bacterial phyla contain known NOB. Here, we report on the discovery of a chemolithoautotrophic nitrite oxidizer that belongs to the widespread phylum Chloroflexi not previously known to contain any nitrifying organism. This organism, named Nitrolancetus hollandicus, was isolated from a nitrifying reactor. Its tolerance to a broad temperature range (25–63?°C) and low affinity for nitrite (Ks=1?m?), a complex layered cell envelope that stains Gram positive, and uncommon membrane lipids composed of 1,2-diols distinguish N. hollandicus from all other known nitrite oxidizers. N. hollandicus grows on nitrite and CO2, and is able to use formate as a source of energy and carbon. Genome sequencing and analysis of N. hollandicus revealed the presence of all genes required for CO2 fixation by the Calvin cycle and a nitrite oxidoreductase (NXR) similar to the NXR forms of the proteobacterial nitrite oxidizers, Nitrobacter and Nitrococcus. Comparative genomic analysis of the nxr loci unexpectedly indicated functionally important lateral gene transfer events between Nitrolancetus and other NOB carrying a cytoplasmic NXR, suggesting that horizontal transfer of the NXR module was a major driver for the spread of the capability to gain energy from nitrite oxidation during bacterial evolution. The surprising discovery of N. hollandicus significantly extends the known diversity of nitrifying organisms and likely will have implications for future research on nitrification in natural and engineered ecosystems. PMID:22763649

  5. Phylogenetic placement of the enigmatic parasite, Polypodium hydriforme, within the Phylum Cnidaria

    PubMed Central

    2008-01-01

    Background Polypodium hydriforme is a parasite with an unusual life cycle and peculiar morphology, both of which have made its systematic position uncertain. Polypodium has traditionally been considered a cnidarian because it possesses nematocysts, the stinging structures characteristic of this phylum. However, recent molecular phylogenetic studies using 18S rDNA sequence data have challenged this interpretation, and have shown that Polypodium is a close relative to myxozoans and together they share a closer affinity to bilaterians than cnidarians. Due to the variable rates of 18S rDNA sequences, these results have been suggested to be an artifact of long-branch attraction (LBA). A recent study, using multiple protein coding markers, shows that the myxozoan Buddenbrockia, is nested within cnidarians. Polypodium was not included in this study. To further investigate the phylogenetic placement of Polypodium, we have performed phylogenetic analyses of metazoans with 18S and partial 28S rDNA sequences in a large dataset that includes Polypodium and a comprehensive sampling of cnidarian taxa. Results Analyses of a combined dataset of 18S and partial 28S sequences, and partial 28S alone, support the placement of Polypodium within Cnidaria. Removal of the long-branched myxozoans from the 18S dataset also results in Polypodium being nested within Cnidaria. These results suggest that previous reports showing that Polypodium and Myxozoa form a sister group to Bilateria were an artifact of long-branch attraction. Conclusion By including 28S rDNA sequences and a comprehensive sampling of cnidarian taxa, we demonstrate that previously conflicting hypotheses concerning the phylogenetic placement of Polypodium can be reconciled. Specifically, the data presented provide evidence that Polypodium is indeed a cnidarian and is either the sister taxon to Hydrozoa, or part of the hydrozoan clade, Leptothecata. The former hypothesis is consistent with the traditional view that Polypodium should be placed in its own cnidarian class, Polypodiozoa. PMID:18471296

  6. In Silico Analysis of the Metabolic Potential and Niche Specialization of Candidate Phylum "Latescibacteria" (WS3)

    PubMed Central

    Youssef, Noha H.; Farag, Ibrahim F.; Rinke, Christian; Hallam, Steven J.; Woyke, Tanja; Elshahed, Mostafa S.

    2015-01-01

    The “Latescibacteria” (formerly WS3), member of the Fibrobacteres–Chlorobi–Bacteroidetes (FCB) superphylum, represents a ubiquitous candidate phylum found in terrestrial, aquatic, and marine ecosystems. Recently, single-cell amplified genomes (SAGs) representing the “Latescibacteria” were obtained from the anoxic monimolimnion layers of Sakinaw Lake (British Columbia, Canada), and anoxic sediments of a coastal lagoon (Etoliko lagoon, Western Greece). Here, we present a detailed in-silico analysis of the four SAGs to gain some insights on their metabolic potential and apparent ecological roles. Metabolic reconstruction suggests an anaerobic fermentative mode of metabolism, as well as the capability to degrade multiple polysaccharides and glycoproteins that represent integral components of green (Charophyta and Chlorophyta) and brown (Phaeophycaea) algae cell walls (pectin, alginate, ulvan, fucan, hydroxyproline-rich glycoproteins), storage molecules (starch and trehalose), and extracellular polymeric substances (EPSs). The analyzed SAGs also encode dedicated transporters for the uptake of produced sugars and amino acids/oligopeptides, as well as an extensive machinery for the catabolism of all transported sugars, including the production of a bacterial microcompartment (BMC) to sequester propionaldehyde, a toxic intermediate produced during fucose and rhamnose metabolism. Finally, genes for the formation of gas vesicles, flagella, type IV pili, and oxidative stress response were found, features that could aid in cellular association with algal detritus. Collectively, these results indicate that the analyzed “Latescibacteria” mediate the turnover of multiple complex organic polymers of algal origin that reach deeper anoxic/microoxic habitats in lakes and lagoons. The implications of such process on our understanding of niche specialization in microbial communities mediating organic carbon turnover in stratified water bodies are discussed. PMID:26039074

  7. Isolation and Characterization of Soil Bacteria That Define Terriglobus gen. nov., in the Phylum Acidobacteria?

    PubMed Central

    Eichorst, Stephanie A.; Breznak, John A.; Schmidt, Thomas M.

    2007-01-01

    Bacteria in the phylum Acidobacteria are widely distributed and abundant in soils, but their ecological roles are poorly understood, owing in part to a paucity of cultured representatives. In a molecular survey of acidobacterial diversity at the Michigan State University Kellogg Biological Station Long-Term Ecological Research site, 27% of acidobacterial 16S rRNA gene clones in a never-tilled, successional plant community belonged to subdivision 1, whose relative abundance varied inversely with soil pH. Strains of subdivision 1 were isolated from these never-tilled soils using low-nutrient medium incubated for 3 to 4 weeks under elevated levels of carbon dioxide, which resulted in a slightly acidified medium that matched the pH optima of the strains (between 5 and 6). Colonies were approximately 1 mm in diameter and either white or pink, the latter due to a carotenoid(s) that was synthesized preferentially under 20% instead of 2% oxygen. Strains were gram-negative, aerobic, chemo-organotrophic, nonmotile rods that produced an extracellular matrix. All strains contained either one or two copies of the 16S rRNA encoding gene, which along with a relatively slow doubling time (10 to 15 h at ca. 23°C) is suggestive of an oligotrophic lifestyle. Six of the strains are sufficiently similar to one another, but distinct from previously named Acidobacteria, to warrant creation of a new genus, Terriglobus, with Terriglobus roseus defined as the type species. The physiological and nutritional characteristics of Terriglobus are consistent with its potential widespread distribution in soil. PMID:17293520

  8. Impact of protozoan cell death on parasite-host interactions and pathogenesis

    Microsoft Academic Search

    Carsten GK Lüder; Jenny Campos-Salinas; Elena Gonzalez-Rey; Ger van Zandbergen

    2010-01-01

    PCD in protozoan parasites has emerged as a fascinating field of parasite biology. This not only relates to the underlying mechanisms and their evolutionary implications but also to the impact on the parasite-host interactions within mammalian hosts and arthropod vectors. During recent years, common functions of apoptosis and autophagy in protozoa and during parasitic infections have emerged. Here, we review

  9. Improvements in transfection efficiency and tests of RNA interference (RNAi) approaches in the protozoan parasite Leishmania

    Microsoft Academic Search

    Kelly A. Robinson; Stephen M. Beverley

    2003-01-01

    Approaches which eliminate mRNA expression directly are ideally suited for reverse genetics applications in eukaryotic microbes which are asexual diploids, such as the protozoan parasite Leishmania. RNA interference (RNAi) approaches have been successful in many species, including the related parasite Trypanosoma brucei. For RNAi tests in Leishmania, we developed improved protocols for transient and stable DNA transfection, attaining efficiencies of

  10. TLR11 Activation of Dendritic Cells by a Protozoan Profilin-Like Protein

    Microsoft Academic Search

    Felix Yarovinsky; Dekai Zhang; John F. Andersen; Gerard L. Bannenberg; Charles N. Serhan; Matthew S. Hayden; Sara Hieny; Fayyaz S. Sutterwala; Richard A. Flavell; Sankar Ghosh; Alan Sher

    2005-01-01

    Mammalian Toll-like receptors (TLRs) play an important role in the innate recognition of pathogens by dendritic cells (DCs). Although TLRs are clearly involved in the detection of bacteria and viruses, relatively little is known about their function in the innate response to eukaryotic microorganisms. Here we identify a profilin-like molecule from the protozoan parasite Toxoplasma gondii that generates a potent

  11. Role of natural killer cells in innate resistance to protozoan infections

    Microsoft Academic Search

    Tanya M Scharton-Kersten; Alan Sher

    1997-01-01

    Natural killer cells are now recognized as major effectors of innate resistance to protozoan parasites. The principal mechanism by which they control the growth of these pathogens is indirect, involving cytokine production rather than cytolytic activity. Recent studies have identified a series of positive and negative signals provided by cytokines and cellular interactions which regulate protozoa-induced natural killer cell function.

  12. Parasitism and chromosome dynamics in protozoan parasites: is there a connection?

    Microsoft Academic Search

    Michael Lanzer; Katja Fischer; Sylvie M. Le Blancq

    1995-01-01

    Genomic plasticity is a hallmark of many protozoan parasites, including Plasmodium spp, Trypanosoma spp, Leishmania ssp and Giardia lamblia. Strikingly, there is a common theme regarding the structural basis of this karyotype variability. Chromosomes are compartmentalized into conserved central domains and polymorphic chromosome ends. Since antigen-encoding genes frequently reside in telomere-proximal domains, it is tempting to speculate that the genetic

  13. Interconnection between organellar functions, development and drug resistance in the protozoan parasite, Toxoplasma gondii

    Microsoft Academic Search

    Stanislas Tomavo; John C. Boothroyd

    1995-01-01

    The protozoan parasite Toxoplasma gondii causes severe disease in animals and humans. In AIDS patients, for example, the encephalitis it produces is a major cause of death. Part of the very successful strategy adopted by the parasite centers on its ability to differentiate from the actively growing tachyzoite form to a chronic, almost latent state called the bradyzoite. The molecular

  14. Survival of Escherichia coli 0157 in a soil protozoan: implications for disease

    Microsoft Academic Search

    John Barker; Tom J Humphrey; Michael W. R Brown

    1999-01-01

    Intra-protozoal growth of bacterial pathogens has been associated with increased environmental survival, virulence and resistance to biocides and antibiotics. Using laboratory microcosms we have shown that Escherichia coli 0157 survives and replicates in a common environmental protozoan, Acanthamoeba polyphaga. As protozoa are widely distributed in soils and effluents, they may constitute an important environmental reservoir for transmission of E. coli

  15. Toxic effect of heavy metals on the activated sludge protozoan community

    Microsoft Academic Search

    Paolo Madoni; Donatella Davoli; Gessica Gorbi; Luciano Vescovi

    1996-01-01

    The acute toxicity of five heavy metals to the protozoan community inhabiting the activated sludge of a waste treatment plant, was determined on the basis of reduction in both cell density and species richness. The activated sludge mixed-liquor was treated with different concentrations of cadmium, copper, chromium (VI), lead, and zinc for a period of 24-h. The experimental results enabled

  16. The relative importance of protozoans, rotifers, and crustaceans in a freshwater zooplankton community1

    Microsoft Academic Search

    Michael L. Pace; John D. Orcutt

    1981-01-01

    A complete analysis of the macro- and microzooplankton of a warm monomictic lake indi- cates that Protozoa dominate the community numerically. During winter mixis, ciliates are found at densities of l-8 x 103*liter-' and constitute up to 32% of the zooplankton community biomass, With summer stratification crustaceans decline, while both the relative and absolute abundance of protozoans and rotifers increase.

  17. ANTIOXIDANT ENZYMES, POTENTIAL VIRULENT FACTORS, IN DIFFERENT STRAINS OF THE OYSTER PROTOZOAN PARASITE, PERKINSUS MARINUS

    EPA Science Inventory

    The oyster protozoan parasite, Perkinsus marinus, is one of the two important parasites causing severe mortality in the eastern oysters (Crassostrea virginica) on the US east coast. Our recent study suggests that P. marinus cells and its extracellular products (ECP) could scaveng...

  18. [Progress on IL-27 in immunity to important protozoan parasitic infections].

    PubMed

    Tong, Xin-Xin; Lv, Fang-Li

    2014-06-01

    Parasitic infection can stimulate a series of immune responses and lead to changes in cytokines. This paper focuses on the progress on the role of IL-27 in immunity to some protozoan infection, caused by Toxoplasma gondii, Leishmania, Plasmodium, and Trypanosoma cruzi. PMID:25223063

  19. Protozoan communities of the Flint River-Lake Blackshear ecosystem (Georgia, USA)

    Microsoft Academic Search

    J. R. Pratt; R. Horwitz; J. Cairns

    1987-01-01

    Freshwater protozoa are poorly characterized in river ecosystems. We report here the richness of the protozoan biotas in relation to environmental gradients from an ecosystematic survey of a large, coastal plain river. Communities were collected from natural and artificial substrates concurrent with water chemistry analysis at 11 sites along the Flint River and Lake Blackshear impoundment. Community similarity, the distribution

  20. Movement of the protozoan pathogen Cryptosporidium parvum through three contrasting soil types

    Microsoft Academic Search

    Jane L. Mawdsley; Alison E. Brooks; Roger J. Merry

    1996-01-01

    The potential for transfer of the protozoan pathogen Cryptosporidium parvum through soil to land drains and, subsequently, water courses following the application of livestock waste to land was monitored in the laboratory using simulated rainfall and intact soil cores. Following irrigation over a 21-day period, Cryptosporidium parvum oocysts applied to the surface of soil cores (initial inoculum concentration 1×108 oocysts

  1. Effects of the Protozoan Parasite Ophryocystis elektroscirrha on the Fitness of Monarch Butterflies ( Danaus plexippus)

    Microsoft Academic Search

    Sonia M. Altizer; Karen S. Oberhauser

    1999-01-01

    We evaluated the effects of the protozoan parasite Ophryocystis elektroscirrha on the survival and reproduction of monarch butterflies. Because larvae in natural populations are likely to experience a wide range of natural parasite population densities, we examined the effects of increasing spore density (0, 10, 100, or 1000 spores per larva) on host fitness. Parasites had little effect on monarch

  2. In vitro effects of temperature and salinity on fatty acid synthesis in the oyster protozoan parasite

    E-print Network

    Hartley, Troy W.

    In vitro effects of temperature and salinity on fatty acid synthesis in the oyster protozoan in revised form 15 January 2004; accepted 2 February 2004 Abstract The effects of temperature and salinity in vitro at 10, 18 and 28 jC in a salinity of 28 psu and 14, 20 and 28 psu at a temperature of 28 jC using

  3. Some protozoan parasites of wild birds from the vicinity of Onderstepoort.

    PubMed

    Thomas, S E; Dobson, L D

    1975-03-01

    The protozoan parasites of wild birds from the vicinity of Onderstepoort are recorded. New host records for the Republic of South Africa are: Haemoproteus in Threskiornis aethiopicus, Francolinus swainsonii, Columba guinea and Streptopelia senegalensis; Leucocytozoon in Anas erythrorhyncha, Netta Erythrophthalma, C. guinea and Passer domesticus and Plasmodium in Numida meleagris. PMID:810756

  4. The Meaning of Death: Evolution and Ecology of Apoptosis in Protozoan Parasites

    E-print Network

    Gardner, Andy

    Review The Meaning of Death: Evolution and Ecology of Apoptosis in Protozoan Parasites Sarah E, United Kingdom Abstract: The discovery that an apoptosis-like, pro- grammed cell death (PCD) occurs their proliferation, not death. The prevailing, and untest- ed, opinion in the literature is that parasites employ

  5. Generation and analysis of expressed sequence tags from the ciliate protozoan parasite Ichthyophthirius multifiliis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ciliate protozoan Ichthyophthirius multifiliis (Ich) is an important parasite of freshwater fish that causes 'white spot disease' leading to significant losses. A genomic resource for large-scale studies of this parasite has been lacking. To study gene expression involved in Ich pathogenesis and...

  6. Effects of Brassica napus seed meal amendment on soil populations of resident bacteria and Naegleria americana, and the unsuitability of arachidonic acid as a protozoan-

    E-print Network

    Cohen, Michael F.

    and Naegleria americana, and the unsuitability of arachidonic acid as a protozoan- specific marker Michael F-707-664-3012 Running title: Microflora of seed meal-amended orchard soil Keywords: orchard soil, protozoan feeding, Streptomyces, Pseudomonas, fatty acid markers #12;Abstract Bacterial and protozoan populations were monitored

  7. Real-time PCR detection of bacteria belonging to the Firmicutes Phylum.

    PubMed

    Haakensen, M; Dobson, C M; Deneer, H; Ziola, B

    2008-07-31

    Members of the bacterial Phylum Firmicutes occupy a wide range of habitats and can be either beneficial or detrimental in diverse settings, including food- and beverage-related industries. Firmicutes are responsible for the vast majority of beer-spoilage incidents and, as such, they have a substantial financial impact in the brewing industry. Rapid detection and identification of a bacterium as a Firmicutes is difficult due to widespread genetic transfer and genome reduction resulting in phenotypic diversity in these bacteria. Here we describe a real-time multiplex PCR to detect and differentiate Firmicutes associated with beer-spoilage from non-Firmicutes bacteria that may be present as benign environmental contaminants. A region of the 16S rRNA gene was identified and predicted to be highly conserved amongst, and essentially specific for, Firmicutes. A real-time PCR assay using a hydrolysis probe targeting this region of the 16S rRNA gene was experimentally shown to detect ten genera of Firmicutes known to be beer spoilers, but does not cross-react with eleven of twelve non-Firmicutes genera which can periodically appear in beer. Only one non-Firmicutes species, Zymomonas mobilis, weakly reacted with the Firmicutes probe. This rPCR assay has a standard curve that is linear over six orders of magnitude of DNA, with a quantitation limit of DNA from <10 bacteria. When used to detect bacteria present in beer, the assay was able to detect 50-100 colony forming units (CFU) of Firmicutes directly from 2.5 cm membranes used to filter 100 ml of contaminated beer. Through incorporation of a 4.7 cm filter and an overnight pre-enrichment incubation, the sensitivity was increased to 2.5-10 CFU per package of beer (341 ml). When multiplexed with a second hydrolysis probe targeting a universal region of the 16S rRNA gene, the assay reliably differentiates between Firmicutes and non-Firmicutes bacteria found in breweries. PMID:18501458

  8. Nematopsis gigas n. sp. (Apicomplexa), a parasite of Nerita ascencionis (Gastropoda, Neritidae) from Brazil.

    PubMed

    Azevedo, Carlos; Padovan, Isaíras

    2004-01-01

    A new species of Nematopsis (Apicomplexa, Porosporidae) is described from the mantle tissues of the seawater gastropod, Nerita ascencionis (Neritidae), collected in the Atlantic North off the coast of "Fernando de Noronha" Island (3 degrees 47' 57'' S, 32 degrees 25' 12'' W) situated about 350 km from the northeast coast of Brazil. Numerous oocysts, each contained in a parasitophorous vacuole, were found in the cytoplasm of phagocytes in the mantle tissue of the host. The phagocytes were surrounded by a thin wall composed of lucent material. The phagocyte cytoplasm contained a nucleus surrounded by numerous vesicles and some dense masses. The oocysts were 21.9 +/- 0.5 microm long, and 11.5 +/- 0.6 microm wide. The oocyst wall was 0.18-0.25 microm thick, and the apical zone contained a micropyle, 1.0-1.2 microm in diameter, covered by a canopy-like operculum about 0.25 microm thick. Externally, the oocyst wall was surrounded by numerous anastomosing microfibrils attached to the wall and extending towards the periphery of the parasitophorous vacuole. Some microfibrils formed a dense complex network that surrounded the oocyst in the middle of the parasitophorous vacuole, which opened only at the apical zone near the external region of the opercular system. On the basis of the data obtained by light and transmission electron microscopy and host specificity, the gregarine Nematopsis gigas is distinguished from the nearest species as a new species. The taxonomic affinities and morphological comparisons with other similar species of the same genus are discussed. PMID:15134258

  9. Coraliomargarita akajimensis gen. nov., sp. nov., a novel member of the phylum 'Verrucomicrobia' isolated from seawater in Japan.

    PubMed

    Yoon, Jaewoo; Yasumoto-Hirose, Mina; Katsuta, Atsuko; Sekiguchi, Hiroshi; Matsuda, Satoru; Kasai, Hiroaki; Yokota, Akira

    2007-05-01

    An obligately aerobic, Gram-negative, non-spore-forming, non-motile, spherical bacterium, designated strain 04OKA010-24(T), was isolated from seawater surrounding the hard coral Galaxea fascicularis L., collected at Majanohama, Akajima, Japan, and was subjected to a polyphasic taxonomic study. Phylogenetic analyses based on the 16S rRNA gene sequence indicated that the new strain represented a member of the phylum 'Verrucomicrobia' and shared 84-95 % sequence similarity with cultivated strains of 'Verrucomicrobia' subdivision 4. Amino acid analysis of the cell-wall hydrolysate indicated the absence of muramic acid and diaminopimelic acid, which suggested that the strain did not contain peptidoglycan in the cell wall. The G+C content of the DNA was 53.9 mol%. MK-7 was the major menaquinone and C(14 : 0), C(18 : 1)omega9c and C(18 : 0) were the major fatty acids. On the basis of these data, it was concluded that strain 04OKA010-24(T) represents a novel species in a new genus in subdivision 4 of the phylum 'Verrucomicrobia', for which the name Coraliomargarita akajimensis gen. nov., sp. nov. is proposed. The type strain of Coraliomargarita akajimensis is 04OKA010-24(T) (=MBIC06463(T)=IAM 15411(T)=KCTC 12865(T)). PMID:17473241

  10. The human gut and groundwater harbor non-photosynthetic bacteria belonging to a new candidate phylum sibling to Cyanobacteria

    PubMed Central

    Di Rienzi, Sara C; Sharon, Itai; Wrighton, Kelly C; Koren, Omry; Hug, Laura A; Thomas, Brian C; Goodrich, Julia K; Bell, Jordana T; Spector, Timothy D; Banfield, Jillian F; Ley, Ruth E

    2013-01-01

    Cyanobacteria were responsible for the oxygenation of the ancient atmosphere; however, the evolution of this phylum is enigmatic, as relatives have not been characterized. Here we use whole genome reconstruction of human fecal and subsurface aquifer metagenomic samples to obtain complete genomes for members of a new candidate phylum sibling to Cyanobacteria, for which we propose the designation ‘Melainabacteria’. Metabolic analysis suggests that the ancestors to both lineages were non-photosynthetic, anaerobic, motile, and obligately fermentative. Cyanobacterial light sensing may have been facilitated by regulators present in the ancestor of these lineages. The subsurface organism has the capacity for nitrogen fixation using a nitrogenase distinct from that in Cyanobacteria, suggesting nitrogen fixation evolved separately in the two lineages. We hypothesize that Cyanobacteria split from Melainabacteria prior or due to the acquisition of oxygenic photosynthesis. Melainabacteria remained in anoxic zones and differentiated by niche adaptation, including for symbiosis in the mammalian gut. DOI: http://dx.doi.org/10.7554/eLife.01102.001 PMID:24137540

  11. Morphological features of elongated-anisotropic magnetosome crystals in magnetotactic bacteria of the Nitrospirae phylum and the Deltaproteobacteria class

    NASA Astrophysics Data System (ADS)

    Lefèvre, Christopher T.; Pósfai, Mihály; Abreu, Fernanda; Lins, Ulysses; Frankel, Richard B.; Bazylinski, Dennis A.

    2011-12-01

    High resolution transmission electron microscopy was used to study the crystallographic habits of the elongated magnetite crystals, variously described as bullet-, tooth- or arrowhead-shaped, in two recently described, uncultured, magnetotactic bacteria belonging to the Nitrospirae phylum designated Candidatus Magnetoovum mohavensis strain LO-1, and Candidatus Thermomagnetovibrio paiutensis strain HSMV-1; and a cultured sulfate-reducing magnetotactic bacterium of the Deltaproteobacteria class of the Proteobacteria phylum designated strain AV-1. The elongation axes of the magnetosomes do not coincide with the easy magnetization axis (which is [111]) but they are parallel to [100] in LO-1 and AV-1 and parallel to [110] in HSMV-1. In all three strains, magnetosome magnetite crystals appear to elongate at constant width, resulting in asymmetric shapes. Idealized crystal morphologies are proposed. Neither the control mechanism over crystal growth, nor the adaptiveness, if any, of such unusual crystal habits are known at the moment. Since similar elongated and asymmetric morphologies are unknown in inorganically-formed magnetite crystals, these forms of magnetosome magnetite appear to be excellent biomarkers.

  12. The Ultramicrobacterium “Elusimicrobium minutum” gen. nov., sp. nov., the First Cultivated Representative of the Termite Group 1 Phylum? †

    PubMed Central

    Geissinger, Oliver; Herlemann, Daniel P. R.; Mörschel, Erhard; Maier, Uwe G.; Brune, Andreas

    2009-01-01

    Insect intestinal tracts harbor several novel, deep-rooting clades of as-yet-uncultivated bacteria whose biology is typically completely unknown. Here, we report the isolation of the first representative of the termite group 1 (TG1) phylum from sterile-filtered gut homogenates of a humivorous scarab beetle larva. Strain Pei191T is a mesophilic, obligately anaerobic ultramicrobacterium with a gram-negative cell envelope. Cells are typically rod shaped, but cultures are pleomorphic in all growth phases (0.3 to 2.5 ?m long and 0.17 to 0.3 ?m wide). The isolate grows heterotrophically on sugars and ferments d-galactose, d-glucose, d-fructose, d-glucosamine, and N-acetyl-d-glucosamine to acetate, ethanol, hydrogen, and alanine as major products but only if amino acids are present in the medium. PCR-based screening and comparative 16S rRNA gene sequence analysis revealed that strain Pei191T belongs to the “intestinal cluster,” a lineage of hitherto uncultivated bacteria present in arthropod and mammalian gut systems. It is only distantly related to the previously described so-called “endomicrobia” lineage, which comprises mainly uncultivated endosymbionts of termite gut flagellates. We propose the name “Elusimicrobium minutum” gen. nov., sp. nov. (type strain, Pei191T = ATCC BAA-1559T = JCM 14958T) for the first isolate of this deep-branching lineage and the name “Elusimicrobia” phyl. nov. for the former TG1 phylum. PMID:19270135

  13. Effect of Nutrient/Carbon Supplements on Biological Phosphate and Nitrate Uptake by Protozoan Isolates

    NASA Astrophysics Data System (ADS)

    Akpor, O. B.; Momba, M. N. B.; Okonkwo, J.

    This study was aimed at investigating the effect of nine different nutrient/carbon supplements in mixed liquor on nutrient uptake ability of three wastewater protozoan isolates, which have previously been screened for phosphate and nitrate uptake efficiency. The results revealed that over 50% of phosphate was removed in the presence of sodium acetate, glucose or sucrose. Similarly, nitrate uptake of over 60% was observed in the presence of sodium acetate, sodium succinate, glucose or sucrose. These trends were common in all the isolates. Chemical Oxygen Demand (COD) removal in the mixed liquor was only found to be significantly removed in mixed liquors that were supplemented with glucose, sucrose or sodium succinate. In the presence of sodium acetate, COD was observed to increase. The findings of this investigation have revealed that nutrient uptake and COD removal by the test protozoan isolates may be dependent primarily on the initial nutrient supplement in mixed liquor.

  14. Protozoan parasites of four species of wild anurans from a local zoo in Malaysia.

    PubMed

    Mohammad, K N; Badrul, M M; Mohamad, N; Zainal-Abidin, A H

    2013-12-01

    The parasitic protozoan fauna in sixty-six anurans comprising of Duttaphrynus melanostictus, Phrynoidis juxtaspera, Hylarana erythraea and Polypedates leucomystax collected from Zoo Negara Malaysia was investigated. The distribution and prevalence rate of parasitic species in the digestive tract and blood were examined. Seven species of intestinal protozoa (Opalina ranarum, Cepedea dimidiata, Nycthetorus cordiformis, Entamoeba ranarum, Iodamoeba butschlii, Endamoeba blattae, and Tritrichomonas sp.) and two species of blood protozoa (Lankesterella sp. and Trypanosoma sp.) were recorded. Opalina ranarum was the most common protozoan found in the rectum and intestine (prevalence rate: 34.8%) infecting all host species, with P. juxtaspera heavily infected with the parasite, whereas Tritrichomonas sp. was the least prevalent intestinal species infecting only D. melanostictus. Both Lankesterella sp. and Trypanosoma sp. were found in the blood of H. erythraea. PMID:24522131

  15. Do you see what I see: Recognition of protozoan parasites by Toll-like receptors.

    PubMed

    Ghosh, Debopam; Stumhofer, Jason S

    2013-08-01

    Toll-like receptors (TLRs) are important for recognizing a variety of pathogens, including protozoan parasites, and initiating innate immune responses against them. TLRs are localized on the cell surface as well as in the endosome, and are implicated in innate sensing of these parasites. In this review, we will discuss recent findings on the identification of parasite-derived pathogen associated molecular patterns and the TLRs that bind them. The role of these TLRs in initiating the immune response against protozoan parasitic infections in vivo will be presented in the context of murine models of infection utilizing TLR-deficient mice. Additionally, we will explore evidence that TLRs and genetic variants of TLRs may impact the outcome of these parasitic infections in humans. PMID:25383072

  16. Parasites and malignancies, a review, with emphasis on digestive cancer induced by Cryptosporidium parvum (Alveolata: Apicomplexa)

    PubMed Central

    Benamrouz, S.; Conseil, V.; Creusy, C.; Calderon, E.; Dei-Cas, E.; Certad, G.

    2012-01-01

    The International Agency for Research on Cancer (IARC) identifies ten infectious agents (viruses, bacteria, parasites) able to induce cancer disease in humans. Among parasites, a carcinogenic role is currently recognized to the digenetic trematodes Schistosoma haematobium, leading to bladder cancer, and to Clonorchis sinensis or Opisthorchis viverrini, which cause cholangiocarcinoma. Furthermore, several reports suspected the potential association of other parasitic infections (due to Protozoan or Metazoan parasites) with the development of neoplastic changes in the host tissues. The present work shortly reviewed available data on the involvement of parasites in neoplastic processes in humans or animals, and especially focused on the carcinogenic power of Cryptosporidium parvum infection. On the whole, infection seems to play a crucial role in the etiology of cancer. PMID:22348213

  17. Transfection and Continuous Expression of Heterologous Genes in the Protozoan Parasite Entamoeba histolytica

    Microsoft Academic Search

    Lutz Hamann; Rose Nickel; Egbert Tannich

    1995-01-01

    To provide tools for functional molecular genetics of the protozoan parasite Entamoeba histolytica, we investigated the use of the prokaryotic neomycin phospho-transferase (NEO) gene as a selectable marker for the transfection of the parasite. An Escherichia coli-derived plasmid vector was constructed (pA5'A3'NEO) containing the NEO coding region flanked by untranslated 5' and 3' sequences of an Ent. histolytica actin gene.

  18. Correlation between the autotrophic index and protozoan colonization rates as indicators of pollution stress

    SciTech Connect

    Cairns, J.; Buikema, A.L.; Yongue, W.H.

    1981-10-01

    The advantages of using microbial communities or multispecies in pollution assessment are discussed. Laboratory and field research assessing the effects of pollution on microbial community structure and function (that is, a ratio of autotrophy to total biomass, protozoan colonization rates, and species richness) indicates that the results are sensitive measures of pollution. The results of one test confirm the results of other tests. All the tests are quick, inexpensive, and reproducible.

  19. Unconventional actins and actin-binding proteins in human protozoan parasites.

    PubMed

    Gupta, C M; Thiyagarajan, S; Sahasrabuddhe, A A

    2015-06-01

    Actin and its regulatory proteins play a key role in several essential cellular processes such as cell movement, intracellular trafficking and cytokinesis in most eukaryotes. While these proteins are highly conserved in higher eukaryotes, a number of unicellular eukaryotic organisms contain divergent forms of these proteins which have highly unusual biochemical and structural properties. Here, we review the biochemical and structural properties of these unconventional actins and their core binding proteins which are present in commonly occurring human protozoan parasites. PMID:25849417

  20. Morphological and Compositional Changes in a Planktonic Bacterial Community in Response to Enhanced Protozoan Grazing

    PubMed Central

    Jürgens, Klaus; Pernthaler, Jakob; Schalla, Sven; Amann, Rudolf

    1999-01-01

    We analyzed changes in bacterioplankton morphology and composition during enhanced protozoan grazing by image analysis and fluorescent in situ hybridization with group-specific rRNA-targeted oligonucleotide probes. Enclosure experiments were conducted in a small, fishless freshwater pond which was dominated by the cladoceran Daphnia magna. The removal of metazooplankton enhanced protozoan grazing pressure and triggered a microbial succession from fast-growing small bacteria to larger grazing-resistant morphotypes. These were mainly different types of filamentous bacteria which correlated in biomass with the population development of heterotrophic nanoflagellates (HNF). Small bacterial rods and cocci, which showed increased proportion after removal of Daphnia and doubling times of 6 to 11 h, belonged nearly exclusively to the beta subdivision of the class Proteobacteria and the Cytophaga-Flavobacterium cluster. The majority of this newly produced bacterial biomass was rapidly consumed by HNF. In contrast, the proportion of bacteria belonging to the gamma and alpha subdivisions of the Proteobacteria increased throughout the experiment. The alpha subdivision consisted mainly of rods that were 3 to 6 ?m in length, which probably exceeded the size range of bacteria edible by protozoa. Initially, these organisms accounted for less than 1% of total bacteria, but after 72 h they became the predominant group of the bacterial assemblage. Other types of grazing-resistant, filamentous bacteria were also found within the beta subdivision of Proteobacteria and the Cytophaga-Flavobacterium cluster. We conclude that the predation regimen is a major structuring force for the bacterial community composition in this system. Protozoan grazing resulted in shifts of the morphological as well as the taxonomic composition of the bacterial assemblage. Grazing-resistant filamentous bacteria can develop within different phylogenetic groups of bacteria, and formerly underepresented taxa might become a dominant group when protozoan predation is the major selective pressure. PMID:10049890

  1. Microvesicles and exosomes as vehicles between protozoan and host cell communication.

    PubMed

    Deolindo, Poliana; Evans-Osses, Ingrid; Ramirez, Marcel Ivan

    2013-02-01

    Cells release extracellular vesicles in response to external factors or in a physiological way. Microvesicles and exosomes originate in cells in different ways and, depending on their contents, may have multiple biological effects on other cells and the environment. The host cell-parasite relationship could be changed dramatically by the plasticity of a new type of communication through extracellular vesicles. In the present paper, we discuss how protozoans use this new resource to evade the immune system and establish infection. PMID:23356292

  2. Impact of Protozoan Grazing on Bacterial Community Structure in Soil Microcosms

    PubMed Central

    Rønn, Regin; McCaig, Allison E.; Griffiths, Bryan S.; Prosser, James I.

    2002-01-01

    The influence of grazing by a mixed assemblage of soil protozoa (seven flagellates and one amoeba) on bacterial community structure was studied in soil microcosms amended with a particulate resource (sterile wheat roots) or a soluble resource (a solution of various organic compounds). Sterilized soil was reinoculated with mixed soil bacteria (obtained by filtering and dilution) or with bacteria and protozoa. Denaturing gradient gel electrophoresis (DGGE) of PCR amplifications of 16S rRNA gene fragments, as well as community level physiological profiling (Biolog plates), suggested that the mixed protozoan community had significant effects on the bacterial community structure. Excising and sequencing of bands from the DGGE gels indicated that high-G+C gram-positive bacteria closely related to Arthrobacter spp. were favored by grazing, whereas the excised bands that decreased in intensity were related to gram-negative bacteria. The percentages of intensity found in bands related to high G+C gram positives increased from 4.5 and 12.6% in the ungrazed microcosms amended with roots and nutrient solution, respectively, to 19.3 and 32.9% in the grazed microcosms. Protozoa reduced the average bacterial cell size in microcosms amended with nutrient solution but not in the treatment amended with roots. Hence, size-selective feeding may explain some but not all of the changes in bacterial community structure. Five different protozoan isolates (Acanthamoeba sp., two species of Cercomonas, Thaumatomonas sp., and Spumella sp.) had different effects on the bacterial communities. This suggests that the composition of protozoan communities is important for the effect of protozoan grazing on bacterial communities. PMID:12450833

  3. Iron-sulphur clusters, their biosynthesis, and biological functions in protozoan parasites.

    PubMed

    Ali, Vahab; Nozaki, Tomoyoshi

    2013-01-01

    Fe-S clusters are ensembles of sulphide-linked di-, tri-, and tetra-iron centres of a variety of metalloproteins that play important roles in reduction and oxidation of mitochondrial electron transport, energy metabolism, regulation of gene expression, cell survival, nitrogen fixation, and numerous other metabolic pathways. The Fe-S clusters are assembled by one of four distinct systems: NIF, SUF, ISC, and CIA machineries. The ISC machinery is a house-keeping system conserved widely from prokaryotes to higher eukaryotes, while the other systems are present in a limited range of organisms and play supplementary roles under certain conditions such as stress. Fe-S cluster-containing proteins and the components required for Fe-S cluster biosynthesis are modulated under stress conditions, drug resistance, and developmental stages. It is also known that a defect in Fe-S proteins and Fe-S cluster biogenesis leads to many genetic disorders in humans, which indicates the importance of the systems. In this review, we describe the biological and physiological significance of Fe-S cluster-containing proteins and their biosynthesis in parasitic protozoa including Plasmodium, Trypanosoma, Leishmania, Giardia, Trichomonas, Entamoeba, Cryptosporidium, Blastocystis, and microsporidia. We also discuss the roles of Fe-S cluster biosynthesis in proliferation, differentiation, and stress response in protozoan parasites. The heterogeneity of the systems and the compartmentalization of Fe-S cluster biogenesis in the protozoan parasites likely reflect divergent evolution under highly diverse environmental niches, and influence their parasitic lifestyle and pathogenesis. Finally, both Fe-S cluster-containing proteins and their biosynthetic machinery in protozoan parasites are remarkably different from those in their mammalian hosts. Thus, they represent a rational target for the development of novel chemotherapeutic and prophylactic agents against protozoan infections. PMID:23876871

  4. Transfection and Transient Expression of Chloramphenicol Acetyltransferase Gene in the Protozoan Parasite Entamoeba Histolytica

    Microsoft Academic Search

    Rose Nickel; Egbert Tannich

    1994-01-01

    Hybrid plasmids were constructed and used for successful transfection and transient expression of the chloramphenicol acetyltransferase (CAT) gene in the protozoan parasite Entamoeba histolytica. Transfection was performed by electroporation of the amebae in a potassium phosphate-based buffer under conditions of 3000 V\\/cm and 25 mu F, resulting in a time constant of 0.4 ms. Expression of CAT activity was achieved

  5. Phylogenetic analysis of the small subunit ribosomal RNA of Marteilia refringens validates the existence of phylum Paramyxea (Desportes and Perkins, 1990).

    PubMed

    Berthe, F C; Le Roux, F; Peyretaillade, E; Peyret, P; Rodriguez, D; Gouy, M; Vivarès, C P

    2000-01-01

    Marteilia refringens is recognized as one of the most significant pathogens of bivalve molluscs. The nucleotide sequence of the small subunit ribosomal RNA gene of Marteilia refringens is used to elucidate the phylogenetic position of the phylum Paramyxea. Genomic DNA was extracted from sporangia of Marteilia, purified from infected blue mussels, Mytilus edulis, and flat oysters, Ostrea edulis. The sequences obtained from Marteilia species purified from both oysters and mussels were identical. The sequence identity was confirmed by in situ hybridization using a DNA probe targeted to a variable region of the ribosomal DNA. The small subunit ribosomal RNA gene sequence of M. refringens is very different from all known sequences of eukaryotic organisms, including those of myxosporeans and haplosporeans. Therefore, the phylum Paramyxea should continue to be recognized as an independent eukaryotic phylum. PMID:10847346

  6. A new coccidian, Isospora rheae sp. nov. (Apicomplexa, Eimeriidae), from Rhea americana (Aves, Rheidae) from South America

    PubMed Central

    Gallo, Samira S.M.; Ederli, Nicole B.; Berto, Bruno P.; de Oliveira, Francisco C.R.

    2014-01-01

    A new species of coccidian (Protozoa: Apicomplexa: Eimeriidae) obtained from rheas, Rhea americana, is reported in Brazil. Oocysts of Isospora rheae sp. nov. are spherical to subspheroidal, measuring 22.6?×?21.0?µm, and have a double and smooth wall that is approximately 1.7?µm thick. The micropyle, oocyst residuum and polar granule are absent. Sporocysts are slightly ovoid, measuring 13.9?×?9.6?µm. The Stieda body is flattened, the substieda body is pointed, irregular and wavy and the sporocyst residuum is composed of scattered granules of varying sizes. Sporozoites have an oblong refractile body and one nucleus. This is the first description of an isosporid coccidian infecting birds of the family Rheidae. PMID:25426418

  7. Efficacy of some anticoccidial drugs for treating coccidial enteritis of the common carp caused by Goussia carpelli (Apicomplexa: Eimeriidae).

    PubMed

    Molnár, K; Ostoros, Györgyi

    2007-03-01

    In this study, nine anticoccidial drugs commonly used in poultry were tested for efficacy for the prevention and treatment of Goussia carpelli (Apicomplexa) infection in common carp (Cyprinus carpio L.). To establish experimental infection with G. carpelli, paratenic host oligochaetes of the genera Tubifex and Limnodrilus were infected with oocysts, and laboratory-cultured parasite-free common carp fingerlings were infected by feeding to them oligochaetes containing sporozoites. The anticoccidial drugs (amprolium, narasin, maduramicin, salinomycin Na, lasalocid Na, diclazuril, robenidine HCl, monensin Na and toltrazuril), mixed in the food of the fish in a dose of 200 mg/kg, were fed for 12 days. Common carp fingerlings fed diclazuril, lasalocid, robenidine HCl or maduramicin and killed on day 14 after exposure were free from infection, while other groups treated with amprolium, toltrazuril, monensin Na, narasin or salinomycin Na harboured oocysts in the mucus and epithelium of the gut. PMID:17385557

  8. A Database of Plastid Protein Families from Red Algae and Apicomplexa and Expression Regulation of the moeB Gene

    PubMed Central

    2015-01-01

    We report the database of plastid protein families from red algae, secondary and tertiary rhodophyte-derived plastids, and Apicomplexa constructed with the novel method to infer orthology. The families contain proteins with maximal sequence similarity and minimal paralogous content. The database contains 6509 protein entries, 513 families and 278 nonsingletons (from which 230 are paralog-free, and among the remaining 48, 46 contain at maximum two proteins per species, and 2 contain at maximum three proteins per species). The method is compared with other approaches. Expression regulation of the moeB gene is studied using this database and the model of RNA polymerase competition. An analogous database obtained for green algae and their symbiotic descendants, and applications based on it are published earlier.

  9. Isospora celata n. sp. (Apicomplexa: Eimeriidae) from the orange-crowned warbler Oreothlypis celata (Say) (Passeriformes: Parulidae) in Mexico.

    PubMed

    Berto, Bruno Pereira; Medina, Juan Pablo; Salgado-Miranda, Celene; García-Conejo, Michele; Janczur, Mariusz Krzysztof; Lopes, Carlos Wilson Gomes; Soriano-Vargas, Edgardo

    2014-11-01

    A new coccidian species (Protista: Apicomplexa: Eimeriidae) is described from the orange-crowned warbler Oreothlypis celata (Say) collected in the Nevado de Toluca National Park, Mexico at 3,000 metres above sea level. Isospora celata n. sp. has subspheroidal oöcysts, measuring 28.4 × 26.4 ?m, with smooth, bi-layered wall c.1.2 ?m thick. Micropyle and polar granule are absent, but oöcyst residuum is present as a compact mass. Sporocysts are ovoidal, 18.2 × 12.8 µm. Stieda body knob-like and sub-Stieda body irregular and barely discernible. Sporocyst residuum is composed of granules of different sizes. Sporozoites are vermiform with one refractile body and a nucleus. This is the third description of an isosporoid coccidian infecting a New World warbler. PMID:25301514

  10. A new species of Eimeria (Apicomplexa: Eimeriidae) from the western hognose snake, Heterodon nasicus (Serpentes: Xenodontidae), from Texas.

    PubMed

    Daszak, Peter; Ball, Stanley J; Streicker, Daniel G; Snow, Keith R

    2011-06-01

    A new species of coccidian (Apicomplexa: Eimeriidae) is described from the feces of a western hognose snake Heterodon nasicus (Serpentes: Xenodontidae) collected from Texas, and housed in the collection of the Zoological Society of London. Oocysts of Eimeria mchenryi n. sp. are cylindrical, 35.0 ± SD 1.4 (32-37) × 17.0 ± 0.7 (16-18) µm; the shape index (length/width) is 2.05. A micropyle, oocyst residuum, and polar granule are absent. Sporocysts are subspherical 9.3 (7-11.5) × 7.7 (6-9) µm, with a shape index of 1.2. There is a sporocyst residuum, but the new species is lacking Stieda bodies. The new species is distinct from those previously named from the Xenodontidae and the allied family, Colubridae. PMID:21506855

  11. A new species of Isospora Schneider, 1881 (Apicomplexa: Eimeriidae) from the white-throated magpie jay Calocitta formosa (Passeriformes: Corvidae) from Costa Rica

    Microsoft Academic Search

    Steve J. Upton; Tom A. Langen; Timothy F. Wright

    1995-01-01

    A new species of isosporan (Apicomplexa: Eimeriidae) is reported from two magpie jays Calocitta formosa (Swainson) (Passeriformes: Corvidae) from Costa Rica. Oöcysts of Isospora calocitta n. sp. are spherical to subpherical, 28.8 × 27.7 (26.5–31.0 × 25.0–29.5) m and have a shape index (length\\/width) of 1.04 (1.00–1.11). A micropyle and oöcyst residuum are absent, but 1–3 polar granules are present.

  12. Phylogenetic Diversity, Localization, and Cell Morphologies of Members of the Candidate Phylum TG3 and a Subphylum in the Phylum Fibrobacteres, Recently Discovered Bacterial Groups Dominant in Termite Guts? †

    PubMed Central

    Hongoh, Yuichi; Deevong, Pinsurang; Hattori, Satoshi; Inoue, Tetsushi; Noda, Satoko; Noparatnaraporn, Napavarn; Kudo, Toshiaki; Ohkuma, Moriya

    2006-01-01

    Recently we discovered two novel, deeply branching lineages in the domain Bacteria from termite guts by PCR-based analyses of 16S rRNA (Y. Hongoh, P. Deevong, T. Inoue, S. Moriya, S. Trakulnaleamsai, M. Ohkuma, C. Vongkaluang, N. Noparatnaraporn, and T. Kudo, Appl. Environ. Microbiol. 71:6590-6599, 2005). Here, we report on the specific detection of these bacteria, the candidate phylum TG3 (Termite Group 3) and a subphylum in the phylum Fibrobacteres, by fluorescence in situ hybridization in the guts of the wood-feeding termites Microcerotermes sp. and Nasutitermes takasagoensis. Both bacterial groups were detected almost exclusively from the luminal fluid of the dilated portion in the hindgut. Each accounted for approximately 10% of the total prokaryotic cells, constituting the second-most dominant groups in the whole-gut microbiota. The detected cells of both groups were in undulate or vibroid forms and apparently resembled small spirochetes. The cell sizes were 0.2 to 0.4 by 1.3 to 6.0 ?m and 0.2 to 0.3 by 1.3 to 4.9 ?m in the TG3 and Fibrobacteres, respectively. Using PCR screenings with specific primers, we found that both groups are distributed among various termites. The obtained clones formed monophyletic clusters that were delineated by the host genus rather than by the geographic distance, implying a robust association between these bacteria and host termites. TG3 clones were also obtained from a cockroach gut, lake sediment, rice paddy soil, and deep-sea sediments. Our results suggest that the TG3 and Fibrobacteres bacteria are autochthonous gut symbionts of various termites and that the TG3 members are also widely distributed among various other environments. PMID:17021231

  13. Measurement of the effects of cadmium stress on protozoan grazing of bacteria (bacterivory) in activated sludge by fluorescence microscopy

    SciTech Connect

    Hoffman, R.L.; Atlas, R.M.

    1987-10-01

    The effect of cadmium stress on protozoan bacterivory in sewage sludge was measured by experimentally exposing sludge communities to 0 to 150 mg of Cd per liter for up to 6 h and then determining the rates of protozoan grazing on bacteria, using a double-staining technique and epifluorescence microscopy. Bacterivory was measured by incubating the sludge with fluorescently labeled bacterium-sized latex beads and directly observing ingestion of the beads and bacterial cells in the sludge by epifluorescence microscopy of preserved samples. Staining with 4',6-diamidino-2-phenylindole and acridine orange permitted the simultaneous determination of protozoan numbers and bacterivory activity as estimated by the number of bacterial cells and bacterium-sized latex beads ingested by the representative ciliate Aspidisca costata. Enumeration with latex beads proved to be an effective way of estimating bacterivory in sludges subjected to heavy-metal stress. This technique should prove useful for determining the effects of other chemical stresses on protozoan numbers and bacterivory in organic-rich environments. Although the number of protozoa declined significantly only after exposure to 100 mg of Cd per liter for 4 h, grazing, as indicated by bead ingestion, was significantly inhibited by Cd concentrations of > 25 mg/liter in < 1 h, and exposure to 100 mg of Cd per liter effectively stopped protozoan grazing within 1 h of exposure. Protozoan ingestion of latex beads and bacteria was inversely correlated to Cd concentration and exposure time. The reduction of protozoan bacterivory by Cd provides a possible explanation for the increase in suspended bacteria in the effluents of metal-stressed treatment facilities.

  14. GRADO DE INFECCIÓN Y MORTALIDAD EN LA GARRAPATA DEL CABALLO Anocentor nitens (ACARI: IXODIDAE) NATURALMENTE INFECTADA POR EL PROTOZOA Babesia caballi (APICOMPLEXA: BABESIIDAE) Infection Degree and Mortality in the Horse Tick Anocentor nitens (Acari: Ixodidae) Naturally Infected by the Protozoan Babesia Caballi (Apicomplexa: Babesiidae)

    Microsoft Academic Search

    Franklin F. Mujica; Carlos Luiz Massard; Marcos Pinheiro Franque; Alfredo Coronado; María Forlano; Claribel Suarez

    2004-01-01

    One hundred and sixty Anocentor nitens infected with Babesia caballi from a horse, naturally infected by B. caballi, were analyzed for the purpose of evaluating both percentage and degree of infection by Babesia caballi, as well as mortality in ticks. Four groups (A, B, C, and D) of 40 females each were conformed . The groups were evaluated at 5,

  15. Evidence of carbon fixation pathway in a bacterium from candidate phylum SBR1093 revealed with genomic analysis.

    PubMed

    Wang, Zhiping; Guo, Feng; Liu, Lili; Zhang, Tong

    2014-01-01

    Autotrophic CO2 fixation is the most important biotransformation process in the biosphere. Research focusing on the diversity and distribution of relevant autotrophs is significant to our comprehension of the biosphere. In this study, a draft genome of a bacterium from candidate phylum SBR1093 was reconstructed with the metagenome of an industrial activated sludge. Based on comparative genomics, this autotrophy may occur via a newly discovered carbon fixation path, the hydroxypropionate-hydroxybutyrate (HPHB) cycle, which was demonstrated in a previous work to be uniquely possessed by some genera from Archaea. This bacterium possesses all of the thirteen enzymes required for the HPHB cycle; these enzymes share 30?50% identity with those in the autotrophic species of Archaea that undergo the HPHB cycle and 30?80% identity with the corresponding enzymes of the mixotrophic species within Bradyrhizobiaceae. Thus, this bacterium might have an autotrophic growth mode in certain conditions. A phylogenetic analysis based on the 16S rRNA gene reveals that the phylotypes within candidate phylum SBR1093 are primarily clustered into 5 clades with a shallow branching pattern. This bacterium is clustered with phylotypes from organically contaminated environments, implying a demand for organics in heterotrophic metabolism. Considering the types of regulators, such as FnR, Fur, and ArsR, this bacterium might be a facultative aerobic mixotroph with potential multi-antibiotic and heavy metal resistances. This is the first report on Bacteria that may perform potential carbon fixation via the HPHB cycle, thus may expand our knowledge of the distribution and importance of the HPHB cycle in the biosphere. PMID:25310003

  16. Bioinformatic analysis of beta carbonic anhydrase sequences from protozoans and metazoans

    PubMed Central

    2014-01-01

    Background Despite the high prevalence of parasitic infections, and their impact on global health and economy, the number of drugs available to treat them is extremely limited. As a result, the potential consequences of large-scale resistance to any existing drugs are a major concern. A number of recent investigations have focused on the effects of potential chemical inhibitors on bacterial and fungal carbonic anhydrases. Among the five classes of carbonic anhydrases (alpha, beta, gamma, delta and zeta), beta carbonic anhydrases have been reported in most species of bacteria, yeasts, algae, plants, and particular invertebrates (nematodes and insects). To date, there has been a lack of knowledge on the expression and molecular structure of beta carbonic anhydrases in metazoan (nematodes and arthropods) and protozoan species. Methods Here, the identification of novel beta carbonic anhydrases was based on the presence of the highly-conserved amino acid sequence patterns of the active site. A phylogenetic tree was constructed based on codon-aligned DNA sequences. Subcellular localization prediction for each identified invertebrate beta carbonic anhydrase was performed using the TargetP webserver. Results We verified a total of 75 beta carbonic anhydrase sequences in metazoan and protozoan species by proteome-wide searches and multiple sequence alignment. Of these, 52 were novel, and contained highly conserved amino acid residues, which are inferred to form the active site in beta carbonic anhydrases. Mitochondrial targeting peptide analysis revealed that 31 enzymes are predicted with mitochondrial localization; one was predicted to be a secretory enzyme, and the other 43 were predicted to have other undefined cellular localizations. Conclusions These investigations identified 75 beta carbonic anhydrases in metazoan and protozoan species, and among them there were 52 novel sequences that were not previously annotated as beta carbonic anhydrases. Our results will not only change the current information in proteomics and genomics databases, but will also suggest novel targets for drugs against parasites. PMID:24447594

  17. Recycling and uptake of Si(OH)4 when protozoan grazers feed on diatoms.

    PubMed

    Schultes, Sabine; Lambert, Christophe; Pondaven, Philippe; Corvaisier, Rudolph; Jansen, Sandra; Ragueneau, Olivier

    2010-04-01

    Herbivory of microzooplankton is an emerging key factor of diatom mortality in the ocean. As part of the microbial loop, protozoan grazers also feed on bacteria that accelerate the degradation of diatom detritus. The potentially pivotal effect of microzooplankton grazing on Si(OH)(4) recycling was investigated with cultures of single-celled diatoms, Thalassiosira pseudonana and Chaetoceros gracilis, and heterotrophic protozoans, the dinoflagellate Oxyrrhis marina and the ciliate Strombidium sp. Both grazers ingested diatoms and the bacteria in the non-axenic cultures. C. gracilis, whose frustule is "armed" with setae, was less suitable as a prey than T. pseudonana. Ingestion rates of T. pseudonana were comparable for O. marina and Strombidium, but the dinoflagellate produced two orders of magnitude more detrital bSiO(2) than the ciliate, due to the higher abundance reached by O. marina. Total net release of Si(OH)(4) was lower in the grazing treatments compared to the control possibly due to the reduced bacterial growth by microzooplankton bacterivory, and to the transient protection of detrital bSiO(2) in discarded feeding vacuoles. Over the first 24h, microzooplankton grazing even led to enhanced uptake of Si(OH)(4) by diatoms, confirming the potential of grazing to influence the silicification of diatom frustules. Subsequently however, the Si dynamics in bottles with grazers turned rapidly from net uptake to net Si(OH)(4) release. Protozoan grazers hence tie Si(OH)(4) recycling into the microbial loop by producing detrital bSiO(2). PMID:20022558

  18. Effect of nickel on nutrient removal by selected indigenous protozoan species in wastewater systems

    PubMed Central

    Kamika, Ilunga; Momba, Maggy N.B.

    2014-01-01

    Nutrient and heavy metal pollutions are major concern worldwide. This study aimed at comparing the effect of Ni2+ on nutrient removal efficiency of four indigenous wastewater protozoan species (Aspidisca sp., Paramecium sp., Peranema sp., Trachelophyllum sp.). Specific physicochemical parameters and microbial growth/die-off were measured using standard methods. The results revealed that protozoan species were able to simultaneously remove phosphate, nitrate and Ni2+ at concentrations ranging between 66.4–99.36%, 56.19–99.88% and 45.98–85.69%, respectively. Peranema sp. appeared to be the isolates with the highest removal of nutrients (Phosphate-99.36% and Nitrate-99.88%) while Paramecium sp. showed higher removal of Ni2+ at 85.69% and low removal of nutrients. Aspidisca sp. was the most sensitive isolate to Ni2+ but with significant nutrient removal (Phosphate-66.4% and Nitrate-56.19%) at 10 mg-N2+/L followed by an inhibition of nutrient removal at Ni2+ concentration greater than 10 mg/L. Significant correlation between the growth rate and nutrient removal (r = 0.806/0.799, p < 0.05 for phosphate and nitrate, respectively) was noted. Except for Peranema sp. which revealed better nutrient removal ability at 10 mg-Ni2+/L, an increase in Ni2+ concentration had a significant effect on nutrient removal efficiency of these indigenous protozoan species. This study suggests that although Ni2+ appeared to be toxic to microbial isolates, its effect at a low concentration (10 mg-Ni2+/L) towards these isolates can be used to enhance the wastewater treatment process for the removal of nutrients. Peranema sp., which was able to remove both Ni2+ and nutrients from wastewater mixed-liquor, can also be used for bioremediation of wastewater systems. PMID:25737645

  19. First record of Ascogregarina taiwanensis (Apicomplexa: Lecudinidae) in North American Aedes albopictus.

    PubMed

    Munstermann, L E; Wesson, D M

    1990-06-01

    Aedes albopictus collected in the East St. Louis, Illinois, area were found infected with the gregarine protozoan, Ascogregarina taiwanensis. Infection rates varied from 67 to 95% at 4 sites and 0 to 10% at 2 others. Lower infection levels were found in Ae. epactius (42%) and Culex restuans (one larva). Four mosquito species were cross-infected in the laboratory with gregarines isolated from field-collected hosts. Aedes atropalpus was 90% susceptible to A. taiwanensis (100% in Ae. albopictus), with abnormal development and some melanization of trophozoites and gametocysts. In Ae. aegypti and Cx. restuans, the experimental infection was much lower (12-56%) and exhibited abnormalities similar to the Ae. atropalpus infections. Ascogregarina oocysts recovered from both Ae. aegypti and Ae. atropalpus hosts were subsequently infective to Ae. albopictus. In Ae. triseriatus, A. taiwanensis infection was very low (25%, 1-2 trophozoites per larva); gametocysts were not observed nor were infectious oocysts obtained. We conclude that A. taiwanensis, newly introduced to the USA with Ae. albopictus, can develop in 4 indigenous mosquito species and can produce deleterious effects in at least 2, Ae. aegypti and Ae. atropalpus. PMID:2370530

  20. Solar and photocatalytic disinfection of protozoan, fungal and bacterial microbes in drinking water

    Microsoft Academic Search

    J. Lonnen; S. Kilvington; S. C. Kehoe; F. Al-Touati; K. G. McGuigan

    2005-01-01

    The ability of solar disinfection (SODIS) and solar photocatalytic (TiO2) disinfection (SPC-DIS) batch-process reactors to inactivate waterborne protozoan, fungal and bacterial microbes was evaluated. After 8h simulated solar exposure (870W\\/m2 in the 300nm–10?m range, 200W\\/m2 in the 300–400nm UV range), both SPC-DIS and SODIS achieved at least a 4 log unit reduction in viability against protozoa (the trophozoite stage of

  1. Arsenic oxidation and bioaccumulation by the acidophilic protozoan, Euglena mutabilis, in acid mine drainage (Carnoulès, France)

    Microsoft Academic Search

    Corinne Casiot; Odile Bruneel; Jean-Christian Personné; Marc Leblanc; Françoise Elbaz-Poulichet

    2004-01-01

    In the acid stream (pH 2.5–4.7) originating from the Carnoulès mine tailings, the acidophilic protozoan Euglena mutabilis grows with extremely high sulfate (1.9–4.9 g\\/l), iron (0.7–1.7 g\\/l) and arsenic concentrations (0.08–0.26 g\\/l). Strong variations in flow rate and high sulfate concentrations (up to 4.9 g\\/l) have been registered in early winter and might be the reason for the reduction in

  2. Macrophage Migration Inhibitory Factor (MIF): A Key Player in Protozoan Infections

    PubMed Central

    de Dios Rosado, Juan; Rodriguez-Sosa, Miriam

    2011-01-01

    Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine produced by the pituitary gland and multiple cell types, including macrophages (Mø), dendritic cells (DC) and T-cells. Upon releases MIF modulates the expression of several inflammatory molecules, such as TNF-?, nitric oxide and cyclooxygenase 2 (COX-2). These important MIF characteristics have prompted investigators to study its role in parasite infections. Several reports have demonstrated that MIF plays either a protective or deleterious role in the immune response to different pathogens. Here, we review the role of MIF in the host defense response to some important protozoan infections. PMID:22110378

  3. 5-Fluorouracil accumulation in green microalgae and its biogenetic transfer into ciliate protozoan.

    PubMed

    Ud-Daula, Asad; Pfister, Gerd; Schramm, Karl-Werner

    2012-04-01

    The study has demonstrated that anticancer drug 5-fluorouracil causes acute toxicity and interferes with the growth of green microalgae, Scenedesmus vacuolatus. It accumulates in microalgae biomass with bioaccumulation factor of 1.84 × 10(4) and further integrates into the DNA and RNA of microalgae. In addition, the labelled microalgae genome is transferred into protozoan Tetrahymena pyriformis on feeding and is retained in the food vacuoles of predator organisms. This biotransfer of labelled 5-fluorouracil via genomic material was evaluated using radioactivity in Tetrahymena cell pellets though radioactivity did not detect anticancer drug in the genome of the predator organism. PMID:22349280

  4. Foodborne Protozoans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identification of the human pathogens Cryptosporidium and Giardia can be grouped into general morphology by microscopy, chemical and immunofluorescent staining methods aiding microscopy, and biochemical and molecular tests. Microscopic observations can be made using brightfield with or without spec...

  5. Effect of anaerobic digestion on oocysts of the protozoan Eimeria tenella.

    PubMed Central

    Lee, M R; Shih, J C

    1988-01-01

    The effect of anaerobic digestion of poultry waste on oocysts of the protozoan Eimeria tenella, a common enteric pathogen that causes coccidiosis in poultry, was investigated in this study. Thermophilic (50 degrees C) and mesophilic (35 degrees C) anaerobic digestors, with poultry manure as the substrate, were inoculated with the oocysts. The oocysts were damaged during anaerobic digestion, as determined by morphological change and loss of their ability to sporulate. The recovered oocysts were tested for their infectivity in young chicks, as measured by body weight gain, mortality, and cecal lesions. Oocysts lost all their infectivity during thermophilic digestion, while oocysts subjected to mesophilic digestion remained moderately infective in comparison with untreated oocysts, which produced severe coccidiosis, high mortality, and low body weight gain in chicks. Oocysts were inactivated at 50 degrees C when they were suspended in digestor fluid or saline. Inactivation at 35 degrees C was significantly stronger in the digestor fluid than in the saline, which implied that factors other than temperature were involved in the lethal effect of anaerobic digestion on protozoan oocysts. In this study we demonstrated that the treatment of animal waste by anaerobic digestion, especially at a thermophilic temperature, has the benefits of pathogen control and protection of human and animal health in a farm environment. Images PMID:3202626

  6. Extracellular conversion of silver ions into silver nanoparticles by protozoan Tetrahymena thermophila.

    PubMed

    Juganson, Katre; Mortimer, Monika; Ivask, Angela; Kasemets, Kaja; Kahru, Anne

    2013-01-01

    In the current study, cell-free exudates of the ciliated protozoan Tetrahymena thermophila were shown to progressively convert silver nitrate to silver nanoparticles (Ag NPs) under illumination at ambient temperature. The formation of Ag NPs in the reaction mixture was evidenced by gradual colour changes, appearance of a specific absorbance peak (420–450 nm) and visualization using scanning electron microscopy coupled to an energy-dispersive X-ray spectrometer. After 2 h of incubation the mean hydrodynamic size of the Ag NPs was 70 nm. Seven days of incubation resulted in larger agglomerates and a significant decrease in silver toxicity to T. thermophila, accompanied by about 100-fold reduction in the silver ion concentration. Protein analysis indicated an extensive extracellular protein binding by the Ag NPs formed in the protozoan exudates. As protozoa are important components in wastewater treatment, their ability to sequester silver ions into a less bioavailable and less toxic form of silver (e.g. NPs) may be one of the adaption mechanisms of ciliate survival in contaminated environments. PMID:24592441

  7. Effect of anaerobic digestion on oocysts of the protozoan Eimeria tenella.

    PubMed

    Lee, M R; Shih, J C

    1988-10-01

    The effect of anaerobic digestion of poultry waste on oocysts of the protozoan Eimeria tenella, a common enteric pathogen that causes coccidiosis in poultry, was investigated in this study. Thermophilic (50 degrees C) and mesophilic (35 degrees C) anaerobic digestors, with poultry manure as the substrate, were inoculated with the oocysts. The oocysts were damaged during anaerobic digestion, as determined by morphological change and loss of their ability to sporulate. The recovered oocysts were tested for their infectivity in young chicks, as measured by body weight gain, mortality, and cecal lesions. Oocysts lost all their infectivity during thermophilic digestion, while oocysts subjected to mesophilic digestion remained moderately infective in comparison with untreated oocysts, which produced severe coccidiosis, high mortality, and low body weight gain in chicks. Oocysts were inactivated at 50 degrees C when they were suspended in digestor fluid or saline. Inactivation at 35 degrees C was significantly stronger in the digestor fluid than in the saline, which implied that factors other than temperature were involved in the lethal effect of anaerobic digestion on protozoan oocysts. In this study we demonstrated that the treatment of animal waste by anaerobic digestion, especially at a thermophilic temperature, has the benefits of pathogen control and protection of human and animal health in a farm environment. PMID:3202626

  8. Thermoflavifilum aggregans gen. nov., sp. nov., a thermophilic and slightly halophilic filamentous bacterium from the phylum Bacteroidetes.

    PubMed

    Anders, Heike; Dunfield, Peter F; Lagutin, Kirill; Houghton, Karen M; Power, Jean F; Mackenzie, Andrew D; Vyssotski, Mikhail; Ryan, Jason L J; Hanssen, Eric G; Moreau, John W; Stott, Matthew B

    2014-04-01

    A strictly aerobic, thermophilic, moderately acidophilic, non-spore-forming bacterium, strain P373(T), was isolated from geothermally heated soil at Waikite, New Zealand. Cells were filamentous rods, 0.2-0.4 µm in diameter and grew in chains up to 80 µm in length. On the basis of 16S rRNA gene sequence similarity, strain P373(T) was shown to belong to the family Chitinophagaceae (class Sphingobacteriia) of the phylum Bacteroidetes, with the most closely related cultivated strain, Chitinophaga pinensis UQM 2034(T), having 87.6?% sequence similarity. Cells stained Gram-negative, and were catalase- and oxidase-positive. The major fatty acids were i-15?:?0 (10.8?%), i-17?:?0 (24.5?%) and i-17?:?0 3-OH (35.2?%). Primary lipids were phosphatidylethanolamine, two unidentified aminolipids and three other unidentified polar lipids. The presence of sulfonolipids (N-acyl-capnines) was observed in the total lipid extract by mass spectrometry. The G+C content of the genomic DNA was 47.3 mol% and the primary respiratory quinone was MK-7. Strain P373(T) grew at 35-63 °C with an optimum temperature of 60 °C, and at pH 5.5-8.7 with an optimum growth pH of 7.3-7.4. NaCl tolerance was up to 5?% (w/v) with an optimum of 0.1-0.25?% (w/v). Cell colonies were non-translucent and pigmented vivid yellow-orange. Cells displayed an oxidative chemoheterotrophic metabolism. The distinct phylogenetic position and the phenotypic characteristics separate strain P373(T) from all other members of the phylum Bacteroidetes and indicate that it represents a novel species in a new genus, for which the name Thermoflavifilum aggregans gen. nov., sp. nov. is proposed. The type strain of the type species is P373(T) (?=?ICMP 20041(T)?=?DSM 27268(T)). PMID:24425740

  9. Complete genome sequence of the extremely acidophilic methanotroph isolate V4, Methylacidiphilum infernorum, a representative of the bacterial phylum Verrucomicrobia

    PubMed Central

    Hou, Shaobin; Makarova, Kira S; Saw, Jimmy HW; Senin, Pavel; Ly, Benjamin V; Zhou, Zhemin; Ren, Yan; Wang, Jianmei; Galperin, Michael Y; Omelchenko, Marina V; Wolf, Yuri I; Yutin, Natalya; Koonin, Eugene V; Stott, Matthew B; Mountain, Bruce W; Crowe, Michelle A; Smirnova, Angela V; Dunfield, Peter F; Feng, Lu; Wang, Lei; Alam, Maqsudul

    2008-01-01

    Background The phylum Verrucomicrobia is a widespread but poorly characterized bacterial clade. Although cultivation-independent approaches detect representatives of this phylum in a wide range of environments, including soils, seawater, hot springs and human gastrointestinal tract, only few have been isolated in pure culture. We have recently reported cultivation and initial characterization of an extremely acidophilic methanotrophic member of the Verrucomicrobia, strain V4, isolated from the Hell's Gate geothermal area in New Zealand. Similar organisms were independently isolated from geothermal systems in Italy and Russia. Results We report the complete genome sequence of strain V4, the first one from a representative of the Verrucomicrobia. Isolate V4, initially named "Methylokorus infernorum" (and recently renamed Methylacidiphilum infernorum) is an autotrophic bacterium with a streamlined genome of ~2.3 Mbp that encodes simple signal transduction pathways and has a limited potential for regulation of gene expression. Central metabolism of M. infernorum was reconstructed almost completely and revealed highly interconnected pathways of autotrophic central metabolism and modifications of C1-utilization pathways compared to other known methylotrophs. The M. infernorum genome does not encode tubulin, which was previously discovered in bacteria of the genus Prosthecobacter, or close homologs of any other signature eukaryotic proteins. Phylogenetic analysis of ribosomal proteins and RNA polymerase subunits unequivocally supports grouping Planctomycetes, Verrucomicrobia and Chlamydiae into a single clade, the PVC superphylum, despite dramatically different gene content in members of these three groups. Comparative-genomic analysis suggests that evolution of the M. infernorum lineage involved extensive horizontal gene exchange with a variety of bacteria. The genome of M. infernorum shows apparent adaptations for existence under extremely acidic conditions including a major upward shift in the isoelectric points of proteins. Conclusion The results of genome analysis of M. infernorum support the monophyly of the PVC superphylum. M. infernorum possesses a streamlined genome but seems to have acquired numerous genes including those for enzymes of methylotrophic pathways via horizontal gene transfer, in particular, from Proteobacteria. Reviewers This article was reviewed by John A. Fuerst, Ludmila Chistoserdova, and Radhey S. Gupta. PMID:18593465

  10. Gregarines infecting Ischnura spp. in Texas, U.S.A., including description of Septemlaterospora rasberryi n. gen. n. sp. (Apicomplexa: Actinocephalidae: Acanthosporinae) and revision of Steganorhynchus dunwoodyi (Apicomplexa: Actinocephalidae: Menosporinae).

    PubMed

    Cook, Tamara J; Smith-Herron, Autumn J

    2014-02-01

    Septemlaterospora rasberryi n. gen. n. sp. (Apicomplexa: Eugregarinida: Actinocephalidae: Acanthosporinae) is described from adults of Ischnura ramburii (Odonata: Zygoptera: Coenagrionidae). Septemlaterospora n. gen is distinguished by the form of the oocysts: terminally truncated heptagonal bipyramids bearing 7 equatorial spines, 1 at each equatorial vertex, 7 terminal spines obliquely inserted at each pole, 1 at each vertex created by polar truncation; 21 spines total. The holdfast is compound, comprising a terminal epimerite and intercalating diamerite; epimerite is a thick disk or linearly crateriform sucker; diamerite is short (less than half of the total holdfast length) and very broadly obdeltoid. Association occurs immediately before syzygy and is cephalolateral and biassociative. Gametocysts are spherical with a conspicuous hyaline coat. Lacking conspicuous sporoducts, they dehisce by simple rupture. Steganorhynchus dunwoodyi is redescribed utilizing a new complete taxonomic data set, consisting of a larger set of metric characters and based on uniformly prepared, permanent specimens. New host and geographic records are reported for Calyxocephalus karyopera, Domadracunculus janovyi, Nubenocephalus secundus, and Steganorhynchus dunwoodyi, and the type host of D. janovyi is amended. PMID:23984837

  11. Geoarchaeota: a new candidate phylum in the Archaea from high-temperature acidic iron mats in Yellowstone National Park

    PubMed Central

    Kozubal, Mark A; Romine, Margaret; Jennings, Ryan deM; Jay, Zack J; Tringe, Susannah G; Rusch, Doug B; Beam, Jacob P; McCue, Lee Ann; Inskeep, William P

    2013-01-01

    Geothermal systems in Yellowstone National Park (YNP) provide an outstanding opportunity to understand the origin and evolution of metabolic processes necessary for life in extreme environments including low pH, high temperature, low oxygen and elevated concentrations of reduced iron. Previous phylogenetic studies of acidic ferric iron mats from YNP have revealed considerable diversity of uncultivated and undescribed archaea. The goal of this study was to obtain replicate de novo genome assemblies for a dominant archaeal population inhabiting acidic iron-oxide mats in YNP. Detailed analysis of conserved ribosomal and informational processing genes indicates that the replicate assemblies represent a new candidate phylum within the domain Archaea referred to here as ‘Geoarchaeota' or ‘novel archaeal group 1 (NAG1)'. The NAG1 organisms contain pathways necessary for the catabolism of peptides and complex carbohydrates as well as a bacterial-like Form I carbon monoxide dehydrogenase complex likely used for energy conservation. Moreover, this novel population contains genes involved in the metabolism of oxygen including a Type A heme copper oxidase, a bd-type terminal oxidase and a putative oxygen-sensing protoglobin. NAG1 has a variety of unique bacterial-like cofactor biosynthesis and transport genes and a Type3-like CRISPR system. Discovery of NAG1 is critical to our understanding of microbial community structure and function in extant thermophilic iron-oxide mats of YNP, and will provide insight regarding the evolution of Archaea in early Earth environments that may have important analogs active in YNP today. PMID:23151644

  12. Catalinimonas niigatensis sp. nov., a novel member of the family Catalimonadaceae within the phylum Bacteroidetes isolated from lake sediment.

    PubMed

    Yoon, Jaewoo; Adachi, Kyoko; Kasai, Hiroaki

    2014-01-01

    A Gram-negative, strictly aerobic, reddish-pink-pigmented, non-motile, rod-shaped strain designated A6F-52(T) was isolated from a lake sediment sample. Preliminary analysis based on the 16S rRNA gene sequence revealed that the novel isolate could be affiliated with the family Catalimonadaceae of the phylum Bacteroidetes and that it showed highest sequence similarity (97.2%) to Catalinimonas alkaloidigena CNU-914(T). The level of DNA-DNA relatedness between strains A6F-52(T) and Catalinimonas alkaloidigena CNU-914(T) was less than 70%, which is accepted as the phylogenetic definition of a species. The DNA G+C content of strain A6F-52(T) was 44.4 mol%; MK-7 was the major menaquinone; and the presence of iso-C15?0, C16?1 ?5C and iso-C17?0 3-OH as the major cellular fatty acids supported the identification of the novel isolate as a member of the genus Catalinimonas. A complex polar lipid profile was present consisting of phosphatidylethanolamine, an unidentified phospholipid, and an unidentified lipid. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel species for which the name Catalinimonas niigatensis sp. nov. is proposed. The type strain of Catalinimonas niigatensis is A6F-52(T) (= KCTC 32474(T) = NBRC 109829(T)). PMID:24646760

  13. Wenyingzhuangia heitensis sp. nov., a new species of the family Flavobacteriaceae within the phylum Bacteroidetes isolated from seawater.

    PubMed

    Yoon, Jaewoo; Kasai, Hiroaki

    2015-03-01

    A Gram-negative, strictly aerobic, beige-pigmented, non-motile, rod-shaped strain designated H-MN17(T) was isolated from seawater in Japan. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the novel isolate was affiliated with the family Flavobacteriaceae within the phylum Bacteroidetes and that it showed highest sequence similarity (97.5 %) to Wenyingzhuangia marina D1(T). The hybridization values for DNA-DNA relatedness between the strains of H-MN17(T) and W. marina D1(T) were lower than 70 %, which is accepted as the phylogenetic definition of a novel species. The DNA G+C content of strain H-MN17(T) was 31.8 mol%; MK-6 was the major menaquinone; and anteiso-C15:0, anteiso-C17:0 and anteiso-C19:0 were identified as the major (>10 %) cellular fatty acids. A complex polar lipid profile was present consisting of phosphatidylethanolamine, three unidentified lipids, three unidentified glycolipids and three unidentified aminolipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel species of the genus Wenyingzhuangia for which the name Wenyingzhuangia heitensis sp. nov. is proposed. The type strain of W. heitensis sp. nov. is H-MN17(T) (=KCTC 42245(T) = NBRC 110601(T)). PMID:25528340

  14. Evidence of Intraflagellar Transport and Apical Complex Formation in a Free-Living Relative of the Apicomplexa

    PubMed Central

    Portman, Neil; Foster, Christie; Walker, Giselle

    2014-01-01

    Since its first description, Chromera velia has attracted keen interest as the closest free-living relative of parasitic Apicomplexa. The life cycle of this unicellular alga is complex and involves a motile biflagellate form. Flagella are thought to be formed in the cytoplasm, a rare phenomenon shared with Plasmodium in which the canonical mode of flagellar assembly, intraflagellar transport, is dispensed with. Here we demonstrate the expression of intraflagellar transport components in C. velia, answering the question of whether this organism has the potential to assemble flagella via the canonical route. We have developed and characterized a culturing protocol that favors the generation of flagellate forms. From this, we have determined a marked shift in the mode of daughter cell production from two to four daughter cells per division as a function of time after passage. We conduct an ultrastructural examination of the C. velia flagellate form by using serial TEM and show that flagellar biogenesis in C. velia occurs prior to cytokinesis. We demonstrate a close association of the flagellar apparatus with a complex system of apical structures, including a micropore, a conoid, and a complex endomembrane system reminiscent of the apical complex of parasitic apicomplexans. Recent work has begun to elucidate the possible flagellar origins of the apical complex, and we show that in C. velia these structures are contemporaneous within a single cell and share multiple connections. We propose that C. velia therefore represents a vital piece in the puzzle of the origins of the apical complex. PMID:24058169

  15. Lymphokine-induced inhibition of growth of Eimeria bovis and Eimeria papillata (Apicomplexa) in cultured bovine monocytes.

    PubMed Central

    Speer, C A; Reduker, D W; Burgess, D E; Whitmire, W M; Splitter, G A

    1985-01-01

    Sporozoites of Eimeria bovis penetrated and developed normally to first-generation meronts in bovine monocytes (BM) and Madin-Darby bovine kidney (MDBK) cells that had been pretreated with culture medium (CM) or supernatant (NS) from nonstimulated bovine T cells. At 240 h after sporozoite inoculation (ASI), the mean percent development (meronts/[sporozoites + meronts]) in CM- and NS-pretreated BM was 52 and 28%, respectively; values for MDBK cells were 36 and 35%, respectively. Pretreatment of BM and MDBK cells with supernatant (ConAS) from concanavalin A-stimulated bovine T cells had no effect on the ability of sporozoites to penetrate cells; however, at 240 h ASI, only 1% of the sporozoites in ConAS-pretreated BM cultures had developed to meronts. In contrast, ConAS had no adverse effect on the ability of E. bovis sporozoites to develop to first-generation meronts in MDBK cells. At 240 h ASI, E. bovis meronts in ConAS-pretreated BM were abnormal in appearance and retarded in development, whereas sporozoites appeared structurally normal by light microscopy. Pretreatment of BM with ConAS had no effect on the ability of sporozoites of Eimeria papillata (Apicomplexa) to penetrate cells. Sporozoites of E. papillata did not develop to meronts in ConAS-pretreated BM and, in contrast to E. bovis, most sporozoites were destroyed intracellularly. Images PMID:3876996

  16. Relative impacts at sites of dredged-material relocation in the coastal environment: a phylum-level meta-analysis approach

    Microsoft Academic Search

    P. J. Somerfield; M. Atkins; S. G. Bolam; K. R. Clarke; E. Garnacho; H. L. Rees; R. Smith; R. M. Warwick

    2006-01-01

    Phylum-level meta-analysis was applied to 192 samples from a variety of dredgings disposal and relocation sites around the\\u000a coast of England and Wales. No consistent relationship was found between the disturbance status of macrobenthic communities\\u000a within disposal sites and the nature or amount of dredgings disposed. Differences between samples within and outside disposal\\u000a sites were generally smaller than differences between

  17. Effect of pH on Isolation and Distribution of Members of Subdivision 1 of the Phylum Acidobacteria Occurring in Soil

    Microsoft Academic Search

    Michelle Sait; Kathryn E. R. Davis; Peter H. Janssen

    2006-01-01

    The pH strongly influenced the development of colonies by members of subdivision 1 of the phylum Acidobacteria on solid laboratory media. Significantly more colonies of this group formed at pH 5.5 than at pH 7.0. At pH 5.5, 7 to 8% of colonies that formed on plates that were incubated for 4 months were formed by subdivision 1 acidobacteria. These

  18. Apoptosis in the malaria protozoan, Plasmodium berghei: a possible mechanism for limiting intensity of infection in the mosquito

    Microsoft Academic Search

    Ebtesam M Al-Olayan; Gwyn T Williams; Hilary Hurd

    2002-01-01

    Death by apoptosis regulates cell numbers in metazoan tissues and it is mediated by activation of caspases and results in characteristic morphological and biochemical changes. We report here that the malaria protozoan, Plasmodium berghei, exhibits features typical of metazoan apoptotic cells including condensation of chromatin, fragmentation of the nuclear DNA and movement of phosphatidylserine from the inner to the outer

  19. Toll-Like Receptor 4 Contributes to Efficient Control of Infection with the Protozoan Parasite Leishmania major

    Microsoft Academic Search

    Pascale Kropf; Marina A. Freudenberg; Manuel Modolell; Helen P. Price; Shanti Herath; Simone Antoniazi; Chris Galanos; Deborah F. Smith; Ingrid Muller

    2004-01-01

    The essential role of Toll-like receptors (TLR) in innate immune responses to bacterial pathogens is increasingly recognized, but very little is known about the role of TLRs in host defense against infections with eukaryotic pathogens. For the present study, we investigated whether TLRs contribute to the innate and acquired immune response to infection with the intracellular protozoan parasite Leishmania major.

  20. A Genome-Wide Over-Expression Screen Identifies Genes Involved in Phagocytosis in the Human Protozoan Parasite, Entamoeba histolytica

    Microsoft Academic Search

    Ada V. King; Brenda H. Welter; Amrita B. Koushik; Lindsay N. Gordon; Lesly A. Temesvari

    2012-01-01

    Functional genomics and forward genetics seek to assign function to all known genes in a genome. Entamoeba histolytica is a protozoan parasite for which forward genetics approaches have not been extensively applied. It is the causative agent of amoebic dysentery and liver abscess, and infection is prevalent in developing countries that cannot prevent its fecal-oral spread. It is responsible for

  1. Molecular characteristics of an immobilization antigen gene of the fish-parasitic protozoan Ichthyophthirius multifiliis strain ARS-6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ichthyophthirius multifiliis, a ciliated protozoan parasite of fish, expresses surface antigens (i-antigens), which react with host antibodies that render them immobile. The nucleotide sequence of an i-antigen gene of Ichthyophthirius multifiliis strain ARS-6 was deduced. The predicted protein of 47...

  2. 295JOURNAL OF RANGE MANAGEMENT53(3), May 2000 Cryptosporidium parvum is a fecal borne protozoan parasite

    E-print Network

    Tate, Kenneth

    295JOURNAL OF RANGE MANAGEMENT53(3), May 2000 Abstract Cryptosporidium parvum is a fecal borne Cryptosporidium parvum (Tyzzer 1912), a fecal-oral protozoan parasite, is an important etiologic agent Cryptosporidium parvum transport from cattle fecal deposits on California rangelands KENNETH W. TATE, EDWARD R

  3. Toxoplasmosis Toxoplasma gondii is a protozoan parasite that can infect many animals, including humans. It belongs to

    E-print Network

    Wood, Marcelo A.

    transplantation. People typically become infected by three principal routes of transmission. · Foodborne · AnimalToxoplasmosis Toxoplasma gondii is a protozoan parasite that can infect many animals, including point in their lives. Most infections are silent and have no ill effect on the patient. Occasionally

  4. Ultrastructural modification of the ciliate protozoan, Colpidium colpoda following chronic exposure to partially degraded crude oil

    SciTech Connect

    Rogerson, A.; Berger, J.

    1982-06-01

    Protozoa are important consumers of the microflora that biodegrade oil spills. In the study presented, the ultrastructural effects induced by chronic oil stress in the ciliate protozoan, Colpidium colpoda are discussed. Colpidia were grown in control cultures containing a dilute organic medium and a dense suspension of prey bacteria. After 20 days' oil exposure, C. colpoda contained more stained cytoplasmic inclusions than ciliates grown in the control media. Although the extent of Sudan Black staining in the oil-stressed cells indicates the presence of lipids, these droplets are better termed lipid-hydrocarbon (LH) inclusions until their definitive composition is known. C. colpoda accumulated significant quantities of lipid-hydrocarbons accounting for up to 20% of their cellular volume. Studies are currently being conducted to characterized these inclusions and to evaluate the effects of feeding these ''oil-labeled'' prey to predators, an important issue with the increasing concern about the biomagnification of environmental pollutants. (JMT)

  5. Adaptation-induced collective dynamics of a single-cell protozoan

    NASA Astrophysics Data System (ADS)

    Ogata, Maiko; Hondou, Tsuyoshi; Hayakawa, Yoshinori; Hayashi, Yoshikatsu; Sugawara, Ken

    2008-01-01

    We investigate the behavior of a single-cell protozoan in a narrow tubular ring. This environment forces them to swim under a one-dimensional periodic boundary condition. Above a critical density, single-cell protozoa aggregate spontaneously without external stimulation. The high-density zone of swimming cells exhibits a characteristic collective dynamics including translation and boundary fluctuation. We analyzed the velocity distribution and turn rate of swimming cells and found that the regulation of the turing rate leads to a stable aggregation and that acceleration of velocity triggers instability of aggregation. These two opposing effects may help to explain the spontaneous dynamics of collective behavior. We also propose a stochastic model for the mechanism underlying the collective behavior of swimming cells.

  6. Rapid Simultaneous Detection of Anti-protozoan Drugs Using a Lateral-Flow Immunoassay Format.

    PubMed

    Fitzgerald, Jenny; Leonard, Paul; Danaher, Martin; O'Kennedy, Richard

    2015-05-01

    This research describes the development of a multi-analyte lateral-flow immunoassay intended for the simultaneous detection of three anti-protozoan drugs (coccidiostats). These drugs, namely, halofuginone, toltrazuril and diclazuril, are used in the treatment of Eimeria spp. infections in cattle, pigs, chickens and turkeys. Coloured carboxylated microspheres were coated with each of the detection antibodies and employed in a lateral-flow assay format for detection of these residues in eggs. Using this approach, halofuginone was detectable at a limit of 10 ng/mL or greater, toltrazuril at 100 ng/mL and, similarly, diclazuril had a detection limit of 100 ng/mL, which is below the maximum allowed residue limit for all three as outlined by EU regulation. This simple cost-efficient assay and analysis method could pave the way for more efficient simultaneous monitoring of small-molecule residues in the future. PMID:25832180

  7. Genetic Predisposition to Self-Curing Infection with the Protozoan Leishmania chagasi: A Genome Wide Scan

    PubMed Central

    Jeronimo, Selma M. B.; Duggal, Priya; Ettinger, Nicholas A.; Nascimento, Eliana T.; Monteiro, Gloria R.; Cabral, Angela P.; Pontes, Núbia N.; Lacerda, Hênio G.; Queiroz, Paula V.; Maia, Carlos G.; Pearson, Richard D.; Blackwell, Jenefer M.; Beaty, Terri H.; Wilson, Mary E.

    2008-01-01

    The protozoan Leishmania chagasi can cause disseminated, fatal visceral leishmaniasis (VL) or asymptomatic human infection. We hypothesized that genetic factors contribute to this variable response to infection. A family study was performed in endemic neighborhoods near Natal, northeast Brazil. Subjects were assessed for VL or asymptomatic infection, defined as a positive delayed type hypersensitivity (DTH) skin test response to Leishmania antigen without disease symptoms. A genome scan of 405 microsatellite markers in 1254 subjects was analyzed for regions of linkage. The results indicated loci of potential linkage to DTH response on chromosomes 2, 13, 15 and 19, and a novel region of potential interest for VL on chromosome 9. An understanding of the genetic factors determining whether an individual will develop symptomatic or asymptomatic infection with L. chagasi may illuminate proteins essential for immune protection against this parasitic disease; findings could reveal strategies for immunotherapy or prevention. PMID:17955446

  8. [A checklist of protozoan and metazoan parasites of the burbot (Lota lota)].

    PubMed

    Zhokhov, A E; Pugacheva, M N

    2012-01-01

    The parasite fauna of the burbot (Lota lota) within its natural range is reviewed. The sent paper summarizes the data on parasites of the burbot from water bodies of Eurasia and North America, based on published monographs, reviewed journals, scientific reports, conference contributions, and PhD theses. The checklist includes all protozoan and metazoan parasites of the burbot. A total of 242 parasite species/taxa were recorded in the burbot (Ki-netoplastomonada--4, Parasitomonada--3, Coccidiomorpha--1. Microsporidea--3, Myxosporidia--35, Pleurostomata--1. Cyrtostomata--3, Peritricha--20. Protozoa incertae sedis--1. Monogenea--8, Cestoda--23, Digenea--50. Nematoda--36, Acanthocephala--28, Hirudinea--11. Bivalvia--5, Crustacea--10). Most parasites belong to digenean trematodes. Most of these species (183 species/taxa) were recorded on Eurasian and only 92--in North America fishes. Several parasite species recorded from the burbot are discussed in relation to host specificity and their geographical distribution. PMID:22586925

  9. Enrichment of specific protozoan populations during in situ bioremediation of uranium-contaminated groundwater

    SciTech Connect

    Holmes, Dawn; Giloteaux, L.; Williams, Kenneth H.; Wrighton, Kelly C.; Wilkins, Michael J.; Thompson, Courtney A.; Roper, Thomas J.; Long, Philip E.; Lovley, Derek

    2013-07-28

    The importance of bacteria in the anaerobic bioremediation of groundwater polluted with organic and/or metal contaminants is well-recognized and in some instances so well understood that modeling of the in situ metabolic activity of the relevant subsurface microorganisms in response to changes in subsurface geochemistry is feasible. However, a potentially significant factor influencing bacterial growth and activity in the subsurface that has not been adequately addressed is protozoan predation of the microorganisms responsible for bioremediation. In field experiments at a uranium-contaminated aquifer located in Rifle, CO, acetate amendments initially promoted the growth of metal-reducing Geobacter species followed by the growth of sulfate-reducers, as previously observed. Analysis of 18S rRNA gene sequences revealed a broad diversity of sequences closely related to known bacteriovorous protozoa in the groundwater prior to the addition of acetate. The bloom of Geobacter species was accompanied by a specific enrichment of sequences most closely related to the amoeboid flagellate, Breviata anathema, which at their peak accounted for over 80% of the sequences recovered. The abundance of Geobacter species declined following the rapid emergence of B. anathema. The subsequent growth of sulfate-reducing Peptococcaceae was accompanied by another specific enrichment of protozoa, but with sequences most similar to diplomonadid flagellates from the family Hexamitidae, which accounted for up to 100% of the sequences recovered during this phase of the bioremediation. These results suggest a prey-predator response with specific protozoa responding to increased availability of preferred prey bacteria. Thus, quantifying the influence of protozoan predation on the growth, activity, and composition of the subsurface bacterial community is essential for predictive modeling of in situ uranium bioremediation strategies.

  10. Contribution of virus-induced lysis and protozoan grazing to benthic bacterial mortality estimated simultaneously in microcosms.

    PubMed

    Fischer, Ulrike R; Wieltschnig, Claudia; Kirschner, Alexander K T; Velimirov, Branko

    2006-08-01

    In contrast to the water column, the fate of bacterial production in freshwater sediments is still a matter of debate. Thus, the importance of virus-induced lysis and protozoan grazing of bacteria was investigated for the first time simultaneously in a silty sediment layer of a mesotrophic oxbow lake. Microcosms were installed in the laboratory in order to study the dynamics of these processes over 15 days. All microbial and physicochemical parameters showed acceptable resemblance to field data observed during a concomitant in situ study, and similar conclusions can be drawn with respect to the quantitative impact of viruses and protozoa on the bacterial compartment. Viral decay rates ranged from undetectable to 0.078 h(-1) (average, 0.033 h(-1)), and the control of bacterial production from below the detection limit to 36% (average, 12%). The contribution of virus-induced lysis of bacteria to the dissolved organic matter pool as well as to benthic bacterial nutrition was low. Ingestion rates of protozoan grazers ranged from undetectable to 24.7 bacteria per heterotrophic nanoflagellate (HNF) per hour (average, 4.8 bacteria HNF(-1) h(-1)) and from undetectable to 73.3 bacteria per ciliate per hour (average, 11.2 bacteria ciliate(-1) h(-1)). Heterotrophic nanoflagellate and ciliates together cropped up to 5% (average, 1%) of bacterial production. The viral impact on bacteria prevailed over protozoan grazing by a factor of 2.5-19.9 (average, 9.5). In sum, these factors together removed up to 36% (average, 12%) of bacterial production. The high number of correlations between viral and protozoan parameters is discussed in view of a possible relationship between virus removal and the presence of protozoan grazers. PMID:16872403

  11. Single-cell genomics reveals the lifestyle of Poribacteria, a candidate phylum symbiotically associated with marine sponges.

    PubMed

    Siegl, Alexander; Kamke, Janine; Hochmuth, Thomas; Piel, Jörn; Richter, Michael; Liang, Chunguang; Dandekar, Thomas; Hentschel, Ute

    2011-01-01

    In this study, we present a single-cell genomics approach for the functional characterization of the candidate phylum Poribacteria, members of which are nearly exclusively found in marine sponges. The microbial consortia of the Mediterranean sponge Aplysina aerophoba were singularized by fluorescence-activated cell sorting, and individual microbial cells were subjected to phi29 polymerase-mediated 'whole-genome amplification'. Pyrosequencing of a single amplified genome (SAG) derived from a member of the Poribacteria resulted in nearly 1.6 Mb of genomic information distributed among 554 contigs analyzed in this study. Approximately two-third of the poribacterial genome was sequenced. Our findings shed light on the functional properties and lifestyle of a possibly ancient bacterial symbiont of marine sponges. The Poribacteria are mixotrophic bacteria with autotrophic CO(2)-fixation capacities through the Wood-Ljungdahl pathway. The cell wall is of Gram-negative origin. The Poribacteria produce at least two polyketide synthases (PKSs), one of which is the sponge-specific Sup-type PKS. Several putative symbiosis factors such as adhesins (bacterial Ig-like domains, lamininin G domain proteins), adhesin-related proteins (ankyrin, fibronectin type III) and tetratrico peptide repeat domain-encoding proteins were identified, which might be involved in mediating sponge-microbe interactions. The discovery of genes coding for 24-isopropyl steroids implies that certain fossil biomarkers used to date the origins of metazoan life on earth may possibly be of poribacterial origin. Single-cell genomic approaches, such as those shown herein, contribute to a better understanding of beneficial microbial consortia, of which most members are, because of the lack of cultivation, inaccessible by conventional techniques. PMID:20613790

  12. Wenyingzhuangia gracilariae sp. nov., a novel marine bacterium of the phylum Bacteroidetes isolated from the red alga Gracilaria vermiculophylla.

    PubMed

    Yoon, Jaewoo; Oku, Naoya; Kasai, Hiroaki

    2015-06-01

    A Gram-negative, strictly aerobic, beige-pigmented, non-motile, rod-shaped bacterial strain designated N5DB13-4(T) was isolated from the red alga Gracilaria vermiculophylla (Rhodophyta) collected at Sodegaura Beach, Chiba, Japan. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the novel isolate is affiliated with the family Flavobacteriaceae within the phylum Bacteroidetes and that it showed highest sequence similarity (97.3 %) to Wenyingzhuangia heitensis H-MN17(T). The hybridization values for DNA-DNA relatedness between the strains N5DB13-4(T) and W. heitensis H-MN17(T) were 34.1 ± 3.5 %, which is below the threshold accepted for the phylogenetic definition of a novel prokaryotic species. The DNA G+C content of strain N5DB13-4(T) was determined to be 31.8 mol%; MK-6 was identified as the major menaquinone; and the presence of iso-C15:0, iso-C15:0 3-OH and iso-C17:0 3-OH as the major (>10 %) cellular fatty acids. A complex polar lipid profile was present consisting of phosphatidylethanolamine, two unidentified glycolipids and four unidentified lipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel species of the genus Wenyingzhuangia for which the name Wenyingzhuangia gracilariae sp. nov. is proposed. The type strain of W. gracilariae sp. nov. is N5DB13-4(T) (=KCTC 42246 (T)=NBRC 110602(T)). PMID:25896307

  13. Exploring the potential of small RNA subunit and ITS sequences for resolving phylogenetic relationships within the phylum Ctenophora.

    PubMed

    Simion, Paul; Bekkouche, Nicolas; Jager, Muriel; Quéinnec, Eric; Manuel, Michaël

    2015-04-01

    Ctenophores are a phylum of non-bilaterian marine (mostly planktonic) animals, characterised by several unique synapomorphies (e.g., comb rows, apical organ). Relationships between and within the nine recognised ctenophore orders are far from understood, notably due to a paucity of phylogenetically informative anatomical characters. Previous attempts to address ctenophore phylogeny using molecular data (18S rRNA) led to poorly resolved trees but demonstrated the paraphyly of the order Cydippida. Here we compiled an updated 18S rRNA data set, notably including a few newly sequenced species representing previously unsampled families (Lampeidae, Euryhamphaeidae), and we constructed an additional more rapidly evolving ITS1 + 5.8S rRNA + ITS2 alignment. These data sets were analysed separately and in combination under a probabilistic framework, using different methods (maximum likelihood, Bayesian inference) and models (e.g., doublet model to accommodate secondary structure; data partitioning). An important lesson from our exploration of these datasets is that the fast-evolving internal transcribed spacer (ITS) regions are useful markers for reconstructing high-level relationships within ctenophores. Our results confirm the paraphyly of the order Cydippida (and thus a "cydippid-like" ctenophore common ancestor) and suggest that the family Mertensiidae could be the sister group of all other ctenophores. The family Lampeidae (also part of the former "Cydippida") is probably the sister group of the order Platyctenida (benthic ctenophores). The order Beroida might not be monophyletic, due to the position of Beroe abyssicola outside of a clade grouping the other Beroe species and members of the "Cydippida" family Haeckeliidae. Many relationships (e.g. between Pleurobrachiidae, Beroida, Cestida, Lobata, Thalassocalycida) remain unresolved. Future progress in understanding ctenophore phylogeny will come from the use of additional rapidly evolving markers and improvement of taxonomic sampling. PMID:25440713

  14. Protomagalhaensia richardsoni n. sp. (Apicomplexa: Eugregarinida: Blabericolidae): a new gregarine parasitizing the giant lobster cockroach, Henschoutedenia flexivitta (Dictyoptera: Blaberidae).

    PubMed

    Fauver, Joseph R; Clopton, Richard E; Clopton, Debra T

    2013-10-01

    Protomagalhaensia richardsoni n. sp. (Apicomplexa: Eugregarinida: Blabericolidae) is described from the giant lobster cockroach, Henschoutedenia flexivitta (Dictyoptera: Blattaria: Blaberidae: Oxyhaloinae: Nauphoetini). Oocysts within the genus are dolioform with polar plates. Those of Protomagalhaensia granulosae, Protomagalhaensia wolfi, and Protomagalhaensia blaberae possess distinct apical spines and a sagittal depression that are absent or reduced in P. richardsoni and Protomagalhaensia cerastes. Oocysts of P. richardsoni are significantly longer with larger sporozoite-bearing cavities than those of P. blaberae, P. cerastes, P. granulosae, and P. wolfi (external oocyst length 8.07 ?m vs. 7.42 ?m, 7.50 ?m, 6.87 ?m, 7.56 ?m, respectively; internal oocyst length 6.94 ?m vs. 6.44 ?m, 6.77 ?m, 6.09 ?m, 6.72 ?m, respectively). All 5 species are also distinguished by unique oocyst length/width ratios. No unique morphological structure distinguishes among the gametocysts of Protomagalhaensia species, but gametocysts of P. richardsoni are significantly shorter than those of P. blaberae, P. cerastes, P. granulosae, and P. wolfi (gametocyst length 184.3 ?m vs. 325.15 ?m, 253.27 ?m, 273.63 ?m, 218.3 ?m, respectively). No structurally unique morphological gamont feature distinguishes among species of Protomagalhaensia. Rather, species distinctions are morphometric in nature. In general, gamonts of P. richardsoni are readily distinguished from those of P. cerastes and P. wolfi based on size alone: the latter species being roughly half the size of P. richardsoni. Gamonts of P. richardsoni are most similar to those of P. granulosae and P. blaberae but with relatively smaller primites and more slender satellites. PMID:23659501

  15. Expressed sequence tag (EST) analysis of Gregarine gametocyst development.

    PubMed

    Omoto, Charlotte K; Toso, Marc; Tang, Keliang; Sibley, L David

    2004-10-01

    Gregarines are protozoan parasites of invertebrates in the phylum Apicomplexa. We employed an expressed sequence tag strategy in order to dissect the molecular processes of sexual or gametocyst development of gregarines. Expressed sequence tags provide a rapid way to identify genes, particularly in organisms for which we have very little molecular information. Analysis of approximately 1800 expressed sequence tags from the gametocyst stage revealed highly expressed genes related to cell division and differentiation. Evidence was found for the role of degradation and recycling in gametocyst development. Numerous additional genes uncovered by expressed sequence tag sequencing should provide valuable tools to investigate gametocyst development as well as for molecular phylogenetics, and comparative genomics in this important group of parasites. PMID:15491589

  16. Virulence of a Legionella anisa strain associated with Pontiac fever: an evaluation using protozoan, cell culture, and guinea pig models.

    PubMed Central

    Fields, B S; Barbaree, J M; Sanden, G N; Morrill, W E

    1990-01-01

    Legionella anisa and the amoeba Hartmannella vermiformis were isolated from an indoor fountain implicated as the infectious reservoir in an outbreak of Pontiac fever. We evaluated the ability of this strain of L. anisa to multiply in cultures of an amoeba (H. vermiformis), a ciliated protozoan (Tetrahymena pyriformis), and human mononuclear cells and to infect guinea pigs. These bacteria multiplied in the culture of H. vermiformis but failed to infect guinea pigs or the cultures of T. pyriformis and human mononuclear cells. These findings suggest that some Legionella spp. may multiply only in specific protozoan hosts. The inability of this strain of L. anisa to multiply in human phagocytic cells may be related to the development of Pontiac fever rather than pneumonic legionellosis in exposed individuals. Further studies are necessary to determine whether the ability of legionellae to infect certain host cells can be correlated to differences in human disease. PMID:2117580

  17. Detection of Infectious Cryptosporidium in Drinking Water Waterborne transmission of the protozoan parasite Cryptosporidium remains a significant threat of disease with severe consequences

    E-print Network

    Detection of Infectious Cryptosporidium in Drinking Water Waterborne transmission of the protozoan parasite Cryptosporidium remains a significant threat of disease with severe consequences for persons to minimize the risk of Cryptosporidium on public health. Properly operating drinking water treatment plants

  18. Pyrinomonas methylaliphatogenes gen. nov., sp. nov., a novel group 4 thermophilic member of the phylum Acidobacteria from geothermal soils.

    PubMed

    Crowe, M A; Power, J F; Morgan, X C; Dunfield, P F; Lagutin, K; Rijpstra, W I C; Rijpstra, I C; Vyssotski, G N S; Sinninghe Damste, J S; Houghton, K M; Ryan, J L J; Stott, M B

    2014-01-01

    An aerobic, thermophilic, moderately acidophilic non-spore-forming bacterium, strain K22(T), was isolated from geothermally heated soil at Mount Ngauruhoe, New Zealand. On the basis of 16S rRNA gene sequence similarity, K22(T) was shown to belong to subdivision 4 of the phylum Acidobacteria and to be most closely related to 'Candidatus Chloracidobacterium thermophilum' (86?%) and Blastocatella fastidiosa (86?%). Cells stained Gram-negative and were catalase and oxidase-positive. The major fatty acids detected were iso-C15?:?0, iso-C17?:?0, iso-C19?:?0 and iso-C21?:?0 when standard lipid extraction protocols were employed. Analysis of the total cell lipid acid hydrolysate also detected membrane-spanning and ether lipids, which made up approximately 40?% of the total membrane composition. These lipids included dicarboxylic (iso-diabolic) acid and the glyceryl ether of alkyl analogues of iso-C15?:?0 and iso-diabolic acid. The G+C content of the genomic DNA was 59.6 mol% and the primary respiratory quinone was MK-8. Strain K22(T) grew at 50-69 °C with an optimum temperature of 65 °C and at pH 4.1-7.8 with an optimum growth pH of 6.5. NaCl tolerance was up to 1?% (w/v). Cells displayed a chemoheterotrophic and obligately aerobic metabolism. Cells grew on nutrient broth, alginate, arabinose, Casamino acids, glucose, lactate, formate, mannose, sodium alginate, peptone, sucrose, tryptone, xanthan, xylan, xylose and yeast extract. Nitrogen sources included nitrate, ammonium, urea, yeast extract and Casamino acids, but not dinitrogen gas. The distinct phylogenetic position and the phenotypic characteristics separate strain K22(T) from all other members of the class Acidobacteria and indicate that it represents a novel species and genus, for which the name Pyrinomonas methylaliphatogenes gen. nov., sp. nov. is proposed. The type strain of the type species is K22(T) (?=?DSM 25857(T)?=?ICMP 18710(T)). PMID:24048862

  19. Nitazoxanide in the treatment of patients with intestinal protozoan and helminthic infections: a report on 546 patients in egypt

    Microsoft Academic Search

    Himly Abaza; Abdul Rahman El-Zayadi; Samir M. Kabil; Hassan Rizk

    1998-01-01

    Nitazoxanide, a new broad-spectrum antiprotozoal\\/anthelmintic drug, was tested in 546 patients with single or multiple intestinal protozoan and helminthic infections. After inclusion in the study, patients at least 12 years of age were instructed to take one nitazoxanide 500-mg table every 12 hours for 3 consecutive days. The guardians of the children aged 4 to 11 years were instructed to

  20. Scyphidia Tholiformis, a Peritrichous Protozoan Found on the Gills and External Surfaces of Micropterus Dolomieu and Micropterus Salmoides

    Microsoft Academic Search

    Eugene W. Surber

    1943-01-01

    Scyphidia tholiformis is an urn-shaped peritrichous protozoan measuring about 59 microns in length and 35 microns in width. It possesses a double row of cilia about one-third of the distance from the anterior end of the body and has a large scopula which is variable in shape and provides a large surface for attachment. The macronucleus is long and band-like,

  1. Phylloseptins: a novel class of anti-bacterial and anti-protozoan peptides from the Phyllomedusa genus

    Microsoft Academic Search

    José Roberto S. A. Leite; Luciano P. Silva; Maria Izabel S. Rodrigues; Maura V. Prates; Guilherme D. Brand; Bruno M. Lacava; Ricardo B. Azevedo; Anamélia L. Bocca; Sergio Albuquerque; Carlos Bloch

    2005-01-01

    Six novel peptides called phylloseptins (PS-1, -2, -3, -4, -5, and -6) showing anti-bacterial (PS-1) and anti-protozoan (PS-4 and -5) activities were isolated from the skin secretion of the Brazilian tree-frogs, Phyllomedusa hypochondrialis and Phyllomedusa oreades. Phylloseptins have a primary structure consisting of 19–21 amino acid residues (1.7–2.1kDa). They have common structural features, such as a highly conserved N-terminal region

  2. [Occurrence of the flagellated protozoan, Cryptobia helicis Leidy, 1846 (Kinetoplasta: Bodonea: Cryptobiidae) in the garden snail, Helix aspersa].

    PubMed

    Göçmen, Bayram; Gürelli, Gözde

    2008-01-01

    In this survey, the prevalence and cytological features of the flagellated protozoan, Cryptobia helicis living in the bursa copulatrix of the garden snail, Helix aspersa Müller 1774 found in the vicinity of Izmir, Turkey was investigated. The prevalence of Cryptobia helicis in garden snails collected in the spring of 2005 was found to be 68.65%. This study is the first record of the occurrence of Cryptobia helicis in the garden snail Helix aspersa found in Turkey. PMID:18351561

  3. Assembly-History Dynamics of a Pitcher-Plant Protozoan Community in Experimental Microcosms

    PubMed Central

    Kadowaki, Kohmei; Inouye, Brian D.; Miller, Thomas E.

    2012-01-01

    Background History drives community assembly through differences both in density (density effects) and in the sequence in which species arrive (sequence effects). Density effects arise from predictable population dynamics, which are free of history, but sequence effects are due to a density-free mechanism, arising solely from the order and timing of immigration events. Few studies have determined how components of immigration history (timing, number of individuals, frequency) alter local dynamics to determine community assembly, beyond addressing when immigration history produces historically contingent assembly. Methods/Findings We varied density and sequence effects independently in a two-way factorial design to follow community assembly in a three-species aquatic protozoan community. A superior competitor, Colpoda steinii, mediated alternative community states; early arrival or high introduction density allowed this species to outcompete or suppress the other competitors (Poterioochromonas malhamensis and Eimeriidae gen. sp.). Multivariate analysis showed that density effects caused greater variation in community states, whereas sequence effects altered the mean community composition. Conclusions A significant interaction between density and sequence effects suggests that we should refine our understanding of priority effects. These results highlight a practical need to understand not only the “ingredients” (species) in ecological communities but their “recipes” as well. PMID:22880069

  4. Genetic variation in resistance, but not tolerance, to a protozoan parasite in the monarch butterfly.

    PubMed

    Lefèvre, Thierry; Williams, Amanda Jo; de Roode, Jacobus C

    2011-03-01

    Natural selection should strongly favour hosts that can protect themselves against parasites. Most studies on animals so far have focused on resistance, a series of mechanisms through which hosts prevent infection, reduce parasite growth or clear infection. However, animals may instead evolve tolerance, a defence mechanism by which hosts do not reduce parasite infection or growth, but instead alleviate the negative fitness consequences of such infection and growth. Here, we studied genetic variation in resistance and tolerance in the monarch butterfly (Danaus plexippus) to its naturally occurring protozoan parasite, Ophryocystis elektroscirrha. We exposed 560 monarch larvae of 19 different family lines to one of five different parasite inoculation doses (0, 1, 5, 10 and 100 infective spores) to create a range of parasite loads in infected butterflies. We then used two proxies of host fitness (adult lifespan and body mass) to quantify: (i) qualitative resistance (the ability to prevent infection; also known as avoidance or anti-infection resistance); (ii) quantitative resistance (the ability to limit parasite growth upon infection; also known as control or anti-growth resistance); and (iii) tolerance (the ability to maintain fitness with increasing parasite infection intensity). We found significant differences among host families in qualitative and quantitative resistance, indicating genetic variation in resistance. However, we found no genetic variation in tolerance. This may indicate that all butterflies in our studied population have evolved maximum tolerance, as predicted by some theoretical models. PMID:20843849

  5. Inferring host range dynamics from comparative data: the protozoan parasites of new world monkeys.

    PubMed

    Waxman, David; Weinert, Lucy A; Welch, John J

    2014-07-01

    Uncovering the ecological determinants of parasite host range is a central goal of comparative parasitology and infectious disease ecology. But while parasites are often distributed nonrandomly across the host phylogeny, such patterns are difficult to interpret without a genealogy for the parasite samples and without knowing what sorts of ecological dynamics might lead to what sorts of nonrandomness. We investigated inferences from comparative data, using presence/absence records from protozoan parasites of the New World monkeys. We first demonstrate several distinct types of phylogenetic signal in these data, showing, for example, that parasite species are clustered on the host tree and that closely related host species harbor similar numbers of parasite species. We then show that all of these patterns can be generated by a single, simple dynamical model, in which parasite host range changes more rapidly than host speciation/extinction and parasites preferentially colonize uninfected host species that are closely related to their existing hosts. Fitting this model to data, we then estimate its parameters. Finally, we caution that quite different ecological processes can lead to similar signatures but show how phylogenetic variation in host susceptibility can be distinguished from a tendency for parasites to colonize closely related hosts. Our new process-based analyses, which estimate meaningful parameters, should be useful for inferring the determinants of parasite host range and transmission success. PMID:24921601

  6. Oxidative stress damage in the protozoan parasite Trypanosoma cruzi is inhibited by Cyclosporin A.

    PubMed

    Bustos, Patricia L; Perrone, Alina E; Milduberger, Natalia; Postan, Miriam; Bua, Jacqueline

    2015-07-01

    Cyclosporin A (CsA) specifically inhibits the mitochondrial permeability transition pore (mPTP). Opening of the mPTP, which is triggered by high levels of matrix [Ca2+] and/or oxidative stress, leads to mitochondrial dysfunction and thus to cell death by either apoptosis or necrosis. In the present study, we analysed the response of Trypanosoma cruzi epimastigote parasites to oxidative stress with 5 mm H2O2, by studying several features related to programmed cell death and the effects of pre-incubation with 1 ? m of CsA. We evaluated TcPARP cleavage, DNA integrity, cytochrome c translocation, Annexin V/propidium iodide staining, reactive oxygen species production. CsA prevented parasite oxidative stress damage as it significantly inhibited DNA degradation, cytochrome c translocation to cytosol and TcPARP cleavage. The calcein-AM/CoCl2 assay, used as a selective indicator of mPTP opening in mammals, was also performed in T. cruzi parasites. H2O2 treatment decreased calcein fluorescence, but this decline was partially inhibited by pre-incubation with CsA. Our results encourage further studies to investigate if there is a mPTP-like pore and a mitochondrial cyclophilin involved in this protozoan parasite. PMID:25823521

  7. Genetic variation in resistance, but not tolerance, to a protozoan parasite in the monarch butterfly

    PubMed Central

    Lefèvre, Thierry; Williams, Amanda Jo; de Roode, Jacobus C.

    2011-01-01

    Natural selection should strongly favour hosts that can protect themselves against parasites. Most studies on animals so far have focused on resistance, a series of mechanisms through which hosts prevent infection, reduce parasite growth or clear infection. However, animals may instead evolve tolerance, a defence mechanism by which hosts do not reduce parasite infection or growth, but instead alleviate the negative fitness consequences of such infection and growth. Here, we studied genetic variation in resistance and tolerance in the monarch butterfly (Danaus plexippus) to its naturally occurring protozoan parasite, Ophryocystis elektroscirrha. We exposed 560 monarch larvae of 19 different family lines to one of five different parasite inoculation doses (0, 1, 5, 10 and 100 infective spores) to create a range of parasite loads in infected butterflies. We then used two proxies of host fitness (adult lifespan and body mass) to quantify: (i) qualitative resistance (the ability to prevent infection; also known as avoidance or anti-infection resistance); (ii) quantitative resistance (the ability to limit parasite growth upon infection; also known as control or anti-growth resistance); and (iii) tolerance (the ability to maintain fitness with increasing parasite infection intensity). We found significant differences among host families in qualitative and quantitative resistance, indicating genetic variation in resistance. However, we found no genetic variation in tolerance. This may indicate that all butterflies in our studied population have evolved maximum tolerance, as predicted by some theoretical models. PMID:20843849

  8. Role of the Ubiquitin-Proteasome Systems in the Biology and Virulence of Protozoan Parasites

    PubMed Central

    Muñoz, Christian; San Francisco, Juan; Gutiérrez, Bessy; González, Jorge

    2015-01-01

    In eukaryotic cells, proteasomes perform crucial roles in many cellular pathways by degrading proteins to enforce quality control and regulate many cellular processes such as cell cycle progression, signal transduction, cell death, immune responses, metabolism, protein-quality control, and development. The catalytic heart of these complexes, the 20S proteasome, is highly conserved in bacteria, yeast, and humans. However, until a few years ago, the role of proteasomes in parasite biology was completely unknown. Here, we summarize findings about the role of proteasomes in protozoan parasites biology and virulence. Several reports have confirmed the role of proteasomes in parasite biological processes such as cell differentiation, cell cycle, proliferation, and encystation. Proliferation and cell differentiation are key steps in host colonization. Considering the importance of proteasomes in both processes in many different parasites such as Trypanosoma, Leishmania, Toxoplasma, and Entamoeba, parasite proteasomes might serve as virulence factors. Several pieces of evidence strongly suggest that the ubiquitin-proteasome pathway is also a viable parasitic therapeutic target. Research in recent years has shown that the proteasome is a valid drug target for sleeping sickness and malaria. Then, proteasomes are a key organelle in parasite biology and virulence and appear to be an attractive new chemotherapeutic target.

  9. Molecular detection of protozoan parasites infecting Apis mellifera colonies in Japan.

    PubMed

    Morimoto, Tomomi; Kojima, Yuriko; Yoshiyama, Mikio; Kimura, Kiyoshi; Yang, Bu; Peng, Guangda; Kadowaki, Tatsuhiko

    2013-02-01

    The role of protozoan parasites in honey bee health and distribution in the world is not well understood. Therefore, we carried out a molecular survey for the presence of Crithidia mellificae and Apicystis bombi in the colonies of both non-native Apis mellifera and native Apis cerana japonica in Japan. We found that A.?mellifera, but not A.?c.?japonica, colonies are parasitized with C.?mellificae and A.?bombi. Their absence in A.?c.?japonica colonies indicates that A.?mellifera is their native host. Nevertheless, the prevalence in A.?mellifera colonies is low compared with other pathogens such as viruses and Nosema microsporidia. Japanese C.?mellificae isolates share well-conserved nuclear-encoded gene sequences with Swiss and US isolates. We have found two Japanese haplotypes (A and B) with two nucleotide differences in the kinetoplast-encoded cytochrome b sequence. The haplotype A is identical to Swiss isolate. These results demonstrate that C.?mellificae and A.?bombi distribute in Asia, Oceania, Europe, and South and North Americas. PMID:23757133

  10. Development of an Aeromonas hydrophila? infection model using the protozoan Tetrahymena thermophila.

    PubMed

    Li, Jing; Zhang, Xiao-Lu; Liu, Yong-Jie; Lu, Cheng-Ping

    2011-03-01

    Aeromonas hydrophila is a motile bacterium present in numerous freshwater habitats worldwide and is frequently the cause of infections in fish and numerous terrestrial vertebrates including humans. Because A. hydrophila is also a component of the normal intestinal flora of healthy fish, virulence mechanisms are not well understood. Considering that fish models used for the examination of A. hydrophila genes associated with virulence have not been well defined, we established an infection model using the free-living, ciliate protozoa Tetrahymena thermophila. The expression of A. hydrophila virulence genes following infection of T. thermophila was assessed by reverse transcription-PCR and demonstrated that the aerolysin (aerA) and Ahe2 serine protease (ahe2) genes (not present in the avirulent A. hydrophila NJ-4 strain) in the virulent J-1 strain were upregulated 4-h postinfection. Furthermore, the presence of intact A. hydrophila J-1 within T. thermophila suggested that these bacteria could interfere with phagocytosis, resulting in the death of the infected protozoan 48-h postinfection. Conversely, A. hydrophila NJ-4-infected T. thermophila survived the infection. This study established a novel T. thermophila infection model that will provide a novel means of examining virulence mechanisms of A. hydrophila. PMID:21204941

  11. Transfection of live, tick derived sporozoites of the protozoan Apicomplexan parasite Theileria parva.

    PubMed

    De Goeyse, Ine; Jansen, Famke; Madder, Maxime; Hayashida, Kyoko; Berkvens, Dirk; Dobbelaere, Dirk; Geysen, Dirk

    2015-03-15

    Theileria parva is an important veterinary protozoan causing the tick-borne disease East Coast fever. Transfection of Theileria parasites will facilitate the investigation of many aspects of this apicomplexan infection and its unique host-parasite interaction. The pathogen has the extraordinary capacity of transforming B and T cells into clonally dividing cancerous cell lines in a reversible way. Sequence data of the entire T. parva genome are available and in vitro infected cell lines can easily be generated, thereby eliminating the use of animals in the evaluation of the evolution of the transfected sporozoites. Here we report, for the first time, on experiments towards successful transient transfection of T. parva sporozoites, making use of a new generation transfection device. Plasmid DNA containing the strong EF-1? promoter and an Azami Green reporter gene were integrated by nucleofection into freshly purified T. parva sporozoites. Expression of Azami Green was detected with a fluorescence microscope and confirmed by counter staining with a monoclonal directed against a sporozoite protein. Despite the fact that transfection efficiencies are still low, this is the first step towards a stable infection method of T. parva parasites. In the long run, transfected parasites might become an alternative way to induce immunity without clinical signs. PMID:25660425

  12. 4-Methylumbelliferyl-?-N-Acetylglucosaminide Hydrolysis by a High-Affinity Enzyme, a Putative Marker of Protozoan Bacterivory

    PubMed Central

    Vrba, Jaroslav; Šimek, Karel; Nedoma, Ji?í; Hartman, Petr

    1993-01-01

    Hydrolysis of an artificial fluorogenic substrate, 4-methylumbelliferyl-?-N-acetylglucosaminide, has been studied in a monoculture predator-prey system with either a flagellate (Bodo saltans) or a ciliate (Cyclidium sp.) fed upon pure bacterial culture (Aeromonas hydrophila or Alcaligenes xylosoxidans). Aeromonas hydrophila produced a low-affinity ?-N-acetylglucosaminidase-like enzyme (Km, ?100 ?mol liter-1) but Alcaligenes xylosoxidans did not. Inoculation of both bacterial strains with bacterivorous protozoa induced the occurrence of another, high-affinity, ?-N-acetylglucosaminidase-like enzyme (Km, <0.5 ?mol liter-1). The latter enzyme showed significant, close correlations with total grazing rates of both B. saltans (r2 = 0.96) and Cyclidium sp. (r2 = 0.89) estimated by using uptake of fluorescently labelled bacteria. Further significant correlations between several protozoan parameters and kinetic parameters of this enzyme suggest its likely protozoan origin. If both types of enzyme occurred together, they could be satisfactorily distinguished by using kinetic data analysis. Hence, measurements of ?-N-acetylglucosaminidase-like activities might be promising to use to improve estimations of protozoan bacterivory. PMID:16349049

  13. Experimental transmission of Sarcocystis muris (Apicomplexa: Sarcocystidae) sporocysts from a naturally infected cat (Felis catus) to immunocompetent and immunocompromised mice.

    PubMed

    Al-Kappany, Y M; Abu-Elwafa, S A; Hilali, M; Rosenthal, B M; Dunams, D B; Dubey, J P

    2013-12-01

    Cats serve as definitive hosts for zoonotic Toxoplasma gondii , a protozoan that threatens human reproductive health, but they also excrete sporocysts of related protozoan that pose no known human health risk. Here we provide the first definitive evidence for natural infection with the enzootic parasite Sarcocystis muris, one such enzootic parasite. Sporulated Sarcocystis sp. sporocysts were found in rectal contents of an adult feral cat ( Felis catus ) in Giza, Egypt. After these sporocysts were orally inoculated into 2 Swiss Webster mice, sarcocysts were found to have developed in skeletal muscles 114 days later. As observed through transmission electron microscopy, the cyst wall corresponded to Type 1, and the parasitophorous vacuolar membrane had tiny outpocketing of blebs (<200 nm thick) that were not invaginated into the interior of the cyst; these structures were identical to the sarcocyst wall described for a Costa Rican isolate of S. muris that has served as an experimental model for nearly 4 decades. Two parasite-free cats fed sarcocyst-infected muscles developed patent infections; fully sporulated sporocysts (10-11 × 7.0 ?m) were found in the lamina propria of small intestines of cats killed 6 and 7 days postinoculation (PI). Interferon gamma gene knockout (KO) mice were orally inoculated with sporocysts from experimentally infected cats, and their tissues were examined histologically; sarcocysts were found in 5 KO mice killed 87, 115, 196, 196, 196 days PI, but no stages were seen in 5 KO mice 10, 14, 14, 18, and 39 days PI. Bradyzoites were released from intramuscular sarcocysts of a KO mouse killed 115 days PI and orally inoculated into 5 KO mice. No stage of Sarcocystis was found in any organ (including intestinal lamina propria) of KO mice killed 4, 8, 81, 190, and 190 days PI, confirming that the definitive host is required to complete the life cycle even in the case of immunodeficient mice. This is the first confirmation of S. muris infection in a naturally infected cat anywhere. PMID:23758571

  14. Genome analysis of Chitinivibrio alkaliphilus gen. nov., sp. nov., a novel extremely haloalkaliphilic anaerobic chitinolytic bacterium from the candidate phylum Termite Group 3.

    PubMed

    Sorokin, Dimitry Y; Gumerov, Vadim M; Rakitin, Andrey L; Beletsky, Alexey V; Damsté, J S Sinninghe; Muyzer, Gerard; Mardanov, Andrey V; Ravin, Nikolai V

    2014-06-01

    Anaerobic enrichments from hypersaline soda lakes with chitin as substrate yielded five closely related anaerobic haloalkaliphilic isolates growing on insoluble chitin by fermentation at pH?10 and salinities up to 3.5?M. The chitinolytic activity was exclusively cell associated. To better understand the biology and evolutionary history of this novel bacterial lineage, the genome of the type strain ACht1 was sequenced. Analysis of the 2.6?Mb draft genome revealed enzymes of chitin-degradation pathways, including secreted cell-bound chitinases. The reconstructed central metabolism revealed pathways enabling the fermentation of polysaccharides, while it lacks the genes needed for aerobic or anaerobic respiration. The Rnf-type complex, oxaloacetate decarboxylase and sodium-transporting V-type adenosine triphosphatase were identified among putative membrane-bound ion pumps. According to 16S ribosomal RNA analysis, the isolates belong to the candidate phylum Termite Group 3, representing its first culturable members. Phylogenetic analysis using ribosomal proteins and taxonomic distribution analysis of the whole proteome supported a class-level classification of ACht1 most probably affiliated to the phylum Fibribacteres. Based on phylogenetic, phenotypic and genomic analyses, the novel bacteria are proposed to be classified as Chitinivibrio alkaliphilus gen. nov., sp. nov., within a novel class Chitinivibrione. PMID:24112708

  15. Twenty years of research into Chlamydia-like organisms: a revolution in our understanding of the biology and pathogenicity of members of the phylum Chlamydiae.

    PubMed

    Taylor-Brown, Alyce; Vaughan, Lloyd; Greub, Gilbert; Timms, Peter; Polkinghorne, Adam

    2015-02-01

    Chlamydiae are obligate intracellular bacteria that share a unique but remarkably conserved biphasic developmental cycle that relies on a eukaryotic host cell for survival. Although the phylum was originally thought to only contain one family, the Chlamydiaceae, a total of nine families are now recognized. These so-called Chlamydia-like organisms (CLOs) are also referred to as 'environmental chlamydiae', as many were initially isolated from environmental sources. However, these organisms are also emerging pathogens, as many, such as Parachlamydia sp., Simkania sp. and Waddlia sp., have been associated with human disease, and others, such as Piscichlamydia sp. and Parilichlamydia sp., have been documented in association with diseases in animals. Their strict intracellular nature and the requirement for cell culture have been a confounding factor in characterizing the biology and pathogenicity of CLOs. Nevertheless, the genomes of seven CLO species have now been sequenced, providing new information on their potential ability to adapt to a wide range of hosts. As new isolation and diagnostic methods advance, we are able to further explore the richness of this phylum with further research likely to help define the true pathogenic potential of the CLOs while also providing insight into the origins of the 'traditional' chlamydiae. PMID:25854000

  16. Aggregata (Protozoa: Apicomplexa) infection in the common octopus Octopus vulgaris from the West Mediterranean Sea: The infection rates and possible effect of faunistic, environmental and ecological factors

    NASA Astrophysics Data System (ADS)

    Mayo-Hernández, E.; Barcala, E.; Berriatua, E.; García-Ayala, A.; Muñoz, P.

    2013-10-01

    Prevalence and distribution of the coccidian parasite Aggregata octopiana (Protozoa: Apicomplexa) in common octopus (Octopus vulgaris) in the Mediterranean Spanish coasts were studied. A total of 114 octopuses were sampled from 30 geographic sectors by trawl fleet, and whitish macroscopic oocysts typical of A. octopiana infection were recorded in 96% of octopuses in the digestive tract and mainly in intestine and spiral caecum. The univariate analysis showed that lesion extension varied according to specific octopus, environmental and faunistic variables. A subsequent multivariable analysis indicated that the risk of macroscopic lesions in the caecum was greater in males compared to females, in octopuses living in deeper compared to shallower waters and in hauls where the crustacean Pagurus excavatus was present. The study provides further evidence of the abundance of A. octopiana in octopus ecosystems urging for further studies to evaluate its health impact. The combined abundance of infected octopuses and P. excavatus merits attention.

  17. Coccidia of New World psittaciform birds (Aves: Psittaciformes): Eimeria ararae n. sp. (Apicomplexa: Eimeriidae) from the blue-and-yellow macaw Ara ararauna (Linnaeus).

    PubMed

    do Bomfim Lopes, Bruno; Berto, Bruno Pereira; de Carvalho Balthazar, Lianna Maria; Coelho, Cleide Domingues; Neves, Daniel Medeiros; Lopes, Carlos Wilson Gomes

    2014-06-01

    In the New World, the avian order Psittaciformes comprises 142 species, yet to date only 3 (2%) of the species have been examined for coccidia, and from these only four species of Eimeria Schneider, 1875 have been described. In this study, a new coccidian species (Protozoa: Apicomplexa: Eimeriidae) obtained from the blue-and-yellow macaw Ara ararauna (Linnaeus) is reported from Brazil. Oöcysts of Eimeria ararae n. sp. are ovoidal, measure 28.7 × 20.2 ?m and have a smooth, bi-layered wall c.1.1 ?m thick. Both micropyle and oöcyst residuum are absent, but polar granules are present. Sporocysts are ovoidal and measure 17.0 × 8.3 µm, with knob-like, prominent Stieda body and sporocyst residuum is composed of granules; sub-Stieda body is absent. Sporozoites are vermiform with one refractile body and a nucleus. This is the fifth description of an eimerid coccidian infecting a New World psittaciform bird. PMID:24832188

  18. Eimeria species (Apicomplexa: Eimeriidae) from arctic ground squirrels (Spermophilus parryii) and red squirrels (Tamiasciurus hudsonicus) in Alaska and in Siberia, Russia.

    PubMed

    Seville, Robert S; Oliver, Clint E; Lynch, Andrew J; Bryant, Michelle C; Duszynski, Donald W

    2005-08-01

    Fecal samples from arctic ground squirrels (Spermophilus parryii) collected in Alaska (n = 90) and Russia (n = 46) and from red squirrels (Tamiasciurus hudsonicus) in Alaska (n = 35) were examined for the presence of Eimeria spp. (Apicomplexa: Eimeriidae). Four species were recovered from arctic ground squirrels, including Eimeria callospermophili (prevalence = 18%), Eimeria cynomysis (23.5%), Eimeria lateralis (19%), and Eimeria morainensis (77%). A single species, Eimeria tamiasciuri (91%), was recovered from red squirrels. Eimerians recovered from arctic ground squirrels represent new host records, and the single species from red squirrels is a new geographic record. Alaskan arctic ground squirrel prevalence was higher for E. callospermophili (Alaska = 22% vs. Russia = 9%), E. cynomysis (34% vs. 2%), and E. lateralis (27% vs. 4%), but not E. morainensis (78% vs. 76%). PMID:17089755

  19. Experimental studies of protozoan response to intense magnetic fields and forces

    NASA Astrophysics Data System (ADS)

    Guevorkian, Karine

    Intense static magnetic fields of up to 31 Tesla were used as a novel tool to manipulate the swimming mechanics of unicellular organisms. It is shown that homogenous magnetic fields alter the swimming trajectories of the single cell protozoan Paramecium caudatum, by aligning them parallel to the applied field. Immobile neutrally buoyant paramecia also oriented in magnetic fields with similar rates as the motile ones. It was established that the magneto-orientation is mostly due to the magnetic torques acting on rigid structures in the cell body and therefore the response is a non-biological, passive response. From the orientation rate of paramecia in various magnetic field strengths, the average anisotropy of the diamagnetic susceptibility of the cell was estimated. It has also been demonstrated that magnetic forces can be used to create increased, decreased and even inverted simulated gravity environments for the investigation of the gravi-responses of single cells. Since the mechanisms by which Earth's gravity affects cell functioning are still not fully understood, a number of methods to simulate different strength gravity environments, such as centrifugation, have been employed. Exploiting the ability to exert magnetic forces on weakly diamagnetic constituents of the cells, we were able to vary the gravity from -8 g to 10 g, where g is Earth's gravity. Investigations of the swimming response of paramecia in these simulated gravities revealed that they actively regulate their swimming speed to oppose the external force. This result is in agreement with centrifugation experiments, confirming the credibility of the technique. Moreover, the Paramecium's swimming ceased in simulated gravity of 10 g, indicating a maximum possible propulsion force of 0.7 nN. The magnetic force technique to simulate gravity is the only earthbound technique that can create increased and decreased simulated gravities in the same experimental setup. These findings establish a general technique for applying continuously variable forces to cells or cell populations suitable for exploring their force transduction mechanisms.

  20. Dramatic Increase in Glycerol Biosynthesis upon Oxidative Stress in the Anaerobic Protozoan Parasite Entamoeba histolytica

    PubMed Central

    Husain, Afzal; Sato, Dan; Jeelani, Ghulam; Soga, Tomoyoshi; Nozaki, Tomoyoshi

    2012-01-01

    Entamoeba histolytica, a microaerophilic enteric protozoan parasite, causes amebic colitis and extra intestinal abscesses in millions of inhabitants of endemic areas. Trophozoites of E. histolytica are exposed to a variety of reactive oxygen and nitrogen species during infection. Since E. histolytica lacks key components of canonical eukaryotic anti-oxidative defense systems, such as catalase and glutathione system, alternative not-yet-identified anti-oxidative defense strategies have been postulated to be operating in E. histolytica. In the present study, we investigated global metabolic responses in E. histolytica in response to H2O2- and paraquat-mediated oxidative stress by measuring charged metabolites on capillary electrophoresis and time-of-flight mass spectrometry. We found that oxidative stress caused drastic modulation of metabolites involved in glycolysis, chitin biosynthesis, and nucleotide and amino acid metabolism. Oxidative stress resulted in the inhibition of glycolysis as a result of inactivation of several key enzymes, leading to the redirection of metabolic flux towards glycerol production, chitin biosynthesis, and the non-oxidative branch of the pentose phosphate pathway. As a result of the repression of glycolysis as evidenced by the accumulation of glycolytic intermediates upstream of pyruvate, and reduced ethanol production, the levels of nucleoside triphosphates were decreased. We also showed for the first time the presence of functional glycerol biosynthetic pathway in E. histolytica as demonstrated by the increased production of glycerol 3-phosphate and glycerol upon oxidative stress. We proposed the significance of the glycerol biosynthetic pathway as a metabolic anti-oxidative defense system in E. histolytica. PMID:23029590

  1. DNA Extraction from Protozoan Oocysts/Cysts in Feces for Diagnostic PCR

    PubMed Central

    2014-01-01

    PCR detection of intestinal protozoa is often restrained by a poor DNA recovery or by inhibitors present in feces. The need for an extraction protocol that can overcome these obstacles is therefore clear. QIAamp® DNA Stool Mini Kit (Qiagen) was evaluated for its ability to recover DNA from oocysts/cysts directly from feces. Twenty-five Giardia-positive, 15 Cryptosporidium-positive, 15 Entamoeba histolytica-positive, and 45 protozoa-free samples were processed as control by microscopy and immunoassay tests. DNA extracts were amplified using 3 sets of published primers. Following the manufacturer's protocol, the kit showed sensitivity and specificity of 100% towards Giardia and Entamoeba. However, for Cryptosporidium, the sensitivity and specificity were 60% (9/15) and 100%, respectively. A series of optimization experiments involving various steps of the kit's protocol were conducted using Cryptosporidium-positive samples. The best DNA recoveries were gained by raising the lysis temperature to the boiling point for 10 min and the incubation time of the InhibitEX tablet to 5 min. Also, using a pre-cooled ethanol for nucleic acid precipitation and small elution volume (50-100 µl) were valuable. The sensitivity of the amended protocol to Cryptosporidium was raised to 100%. Cryptosporidium DNA was successfully amplified by either the first or the second primer set. When applied on parasite-free feces spiked with variable oocysts/cysts counts, ? 2 oocysts/cysts were theoretically enough for detection by PCR. To conclude, the Qiagen kit with the amended protocol was proved to be suitable for protozoan DNA extraction directly from feces and support PCR diagnosis. PMID:25031466

  2. DNA extraction from protozoan oocysts/cysts in feces for diagnostic PCR.

    PubMed

    Hawash, Yousry

    2014-06-01

    PCR detection of intestinal protozoa is often restrained by a poor DNA recovery or by inhibitors present in feces. The need for an extraction protocol that can overcome these obstacles is therefore clear. QIAamp® DNA Stool Mini Kit (Qiagen) was evaluated for its ability to recover DNA from oocysts/cysts directly from feces. Twenty-five Giardia-positive, 15 Cryptosporidium-positive, 15 Entamoeba histolytica-positive, and 45 protozoa-free samples were processed as control by microscopy and immunoassay tests. DNA extracts were amplified using 3 sets of published primers. Following the manufacturer's protocol, the kit showed sensitivity and specificity of 100% towards Giardia and Entamoeba. However, for Cryptosporidium, the sensitivity and specificity were 60% (9/15) and 100%, respectively. A series of optimization experiments involving various steps of the kit's protocol were conducted using Cryptosporidium-positive samples. The best DNA recoveries were gained by raising the lysis temperature to the boiling point for 10 min and the incubation time of the InhibitEX tablet to 5 min. Also, using a pre-cooled ethanol for nucleic acid precipitation and small elution volume (50-100 µl) were valuable. The sensitivity of the amended protocol to Cryptosporidium was raised to 100%. Cryptosporidium DNA was successfully amplified by either the first or the second primer set. When applied on parasite-free feces spiked with variable oocysts/cysts counts, ? 2 oocysts/cysts were theoretically enough for detection by PCR. To conclude, the Qiagen kit with the amended protocol was proved to be suitable for protozoan DNA extraction directly from feces and support PCR diagnosis. PMID:25031466

  3. Molecular evidence for bacterial and protozoan pathogens in hard ticks from Romania.

    PubMed

    Ionita, Mariana; Mitrea, Ioan Liviu; Pfister, Kurt; Hamel, Dietmar; Silaghi, Cornelia

    2013-09-01

    The aim of the present study was to provide a preliminary insight into the diversity of tick-borne pathogens circulating at the domestic host-tick interface in Romania. For this, feeding and questing ticks were analyzed by real-time polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis, Borrelia burgdorferi sensu latu, and by PCR and subsequent sequencing for Rickettsia spp., Babesia spp. and Theileria spp. A total of 382 ticks, encompassing 5 species from 4 genera, were collected in April-July 2010 from different areas of Romania; of them, 40 were questing ticks and the remainder was collected from naturally infested cattle, sheep, goats, horses or dogs. Tick species analyzed included Ixodes ricinus, Dermacentor marginatus, Hyalomma marginatum, Rhipicephalus bursa, and Rhipicephalus sanguineus. Four rickettsiae of the spotted fever group of zoonotic concern were identified for the first time in Romania: Rickettsia monacensis and Rickettsia helvetica in I. ricinus, and Rickettsia slovaca and Rickettsia raoultii in D. marginatus. Other zoonotic pathogens such as A. phagocytophilum, Borrelia afzelii, and Babesia microti were found in I. ricinus. Pathogens of veterinary importance were also identified, including Theileria equi in H. marginatum, Babesia occultans in D. marginatus and H. marginatum, Theileria orientalis/sergenti/buffeli-group in I. ricinus and in H. marginatum and E. canis in R. sanguineus. These findings show a wide distribution of very diverse bacterial and protozoan pathogens at the domestic host-tick interface in Romania, with the potential of causing both animal and human diseases. PMID:23428204

  4. Functional Characterization of Peroxiredoxins from the Human Protozoan Parasite Giardia intestinalis

    PubMed Central

    Testa, Fabrizio; Pucillo, Leopoldo Paolo; Teixeira, Miguel; Sarti, Paolo; Saraiva, Lígia M.; Giuffrè, Alessandro

    2014-01-01

    The microaerophilic protozoan parasite Giardia intestinalis, causative of one of the most common human intestinal diseases worldwide, infects the mucosa of the proximal small intestine, where it has to cope with O2 and nitric oxide (NO). Elucidating the antioxidant defense system of this pathogen lacking catalase and other conventional antioxidant enzymes is thus important to unveil novel potential drug targets. Enzymes metabolizing O2, NO and superoxide anion (O2?•) have been recently reported for Giardia, but it is yet unknown how the parasite copes with H2O2 and peroxynitrite (ONOO?). Giardia encodes two yet uncharacterized 2-cys peroxiredoxins (Prxs), GiPrx1a and GiPrx1b. Peroxiredoxins are peroxidases implicated in virulence and drug resistance in several parasitic protozoa, able to protect from nitroxidative stress and repair oxidatively damaged molecules. GiPrx1a and a truncated form of GiPrx1b (deltaGiPrx1b) were expressed in Escherichia coli, purified and functionally characterized. Both Prxs effectively metabolize H2O2 and alkyl-hydroperoxides (cumyl- and tert-butyl-hydroperoxide) in the presence of NADPH and E. coli thioredoxin reductase/thioredoxin as the reducing system. Stopped-flow experiments show that both proteins in the reduced state react with ONOO? rapidly (k?=?4×105 M?1 s?1 and 2×105 M?1 s?1 at 4°C, for GiPrx1a and deltaGiPrx1b, respectively). Consistent with a protective role against oxidative stress, expression of GiPrx1a (but not deltaGiPrx1b) is induced in parasitic cells exposed to air O2 for 24 h. Based on these results, GiPrx1a and deltaGiPrx1b are suggested to play an important role in the antioxidant defense of Giardia, possibly contributing to pathogenesis. PMID:24416465

  5. Functional characterization of peroxiredoxins from the human protozoan parasite Giardia intestinalis.

    PubMed

    Mastronicola, Daniela; Falabella, Micol; Testa, Fabrizio; Pucillo, Leopoldo Paolo; Teixeira, Miguel; Sarti, Paolo; Saraiva, Lígia M; Giuffrè, Alessandro

    2014-01-01

    The microaerophilic protozoan parasite Giardia intestinalis, causative of one of the most common human intestinal diseases worldwide, infects the mucosa of the proximal small intestine, where it has to cope with O2 and nitric oxide (NO). Elucidating the antioxidant defense system of this pathogen lacking catalase and other conventional antioxidant enzymes is thus important to unveil novel potential drug targets. Enzymes metabolizing O2, NO and superoxide anion (O2 (-•)) have been recently reported for Giardia, but it is yet unknown how the parasite copes with H2O2 and peroxynitrite (ONOO(-)). Giardia encodes two yet uncharacterized 2-cys peroxiredoxins (Prxs), GiPrx1a and GiPrx1b. Peroxiredoxins are peroxidases implicated in virulence and drug resistance in several parasitic protozoa, able to protect from nitroxidative stress and repair oxidatively damaged molecules. GiPrx1a and a truncated form of GiPrx1b (deltaGiPrx1b) were expressed in Escherichia coli, purified and functionally characterized. Both Prxs effectively metabolize H2O2 and alkyl-hydroperoxides (cumyl- and tert-butyl-hydroperoxide) in the presence of NADPH and E. coli thioredoxin reductase/thioredoxin as the reducing system. Stopped-flow experiments show that both proteins in the reduced state react with ONOO(-) rapidly (k?=?4×10(5) M(-1) s(-1) and 2×10(5) M(-1) s(-1) at 4°C, for GiPrx1a and deltaGiPrx1b, respectively). Consistent with a protective role against oxidative stress, expression of GiPrx1a (but not deltaGiPrx1b) is induced in parasitic cells exposed to air O2 for 24 h. Based on these results, GiPrx1a and deltaGiPrx1b are suggested to play an important role in the antioxidant defense of Giardia, possibly contributing to pathogenesis. PMID:24416465

  6. Drug repurposing: mining protozoan proteomes for targets of known bioactive compounds

    PubMed Central

    Sateriale, Adam; Bessoff, Kovi; Sarkar, Indra Neil; Huston, Christopher D

    2014-01-01

    Objective To identify potential opportunities for drug repurposing by developing an automated approach to pre-screen the predicted proteomes of any organism against databases of known drug targets using only freely available resources. Materials and methods We employed a combination of Ruby scripts that leverage data from the DrugBank and ChEMBL databases, MySQL, and BLAST to predict potential drugs and their targets from 13 published genomes. Results from a previous cell-based screen to identify inhibitors of Cryptosporidium parvum growth were used to validate our in-silico prediction method. Results In-vitro validation of these results, using a cell-based C parvum growth assay, showed that the predicted inhibitors were significantly more likely than expected by chance to have confirmed activity, with 8.9–15.6% of predicted inhibitors confirmed depending on the drug target database used. This method was then used to predict inhibitors for the following 13 disease-causing protozoan parasites, including: C parvum, Entamoeba histolytica, Giardia intestinalis, Leishmania braziliensis, Leishmania donovani, Leishmania major, Naegleria gruberi (in proxy of Naegleria fowleri), Plasmodium falciparum, Plasmodium vivax, Toxoplasma gondii, Trichomonas vaginalis, Trypanosoma brucei and Trypanosoma cruzi. Conclusions Although proteome-wide screens for drug targets have disadvantages, in-silico methods can be developed that are fast, broad, inexpensive, and effective. In-vitro validation of our results for C parvum indicate that the method presented here can be used to construct a library for more directed small molecule screening, or pipelined into structural modeling and docking programs to facilitate target-based drug development. PMID:23757409

  7. ENTERIC COCCIDIOSIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coccidia are obligate intracellular parasites normally found in the intestinal tract. They belong to phylum Apicomplexa, class Sporozoasida, order Eucoccidiorida, and, depending on the species, family Eimeriidae, Cryptosporidiidae, or Sarcocystidae. Coccidian genera that infect cats and dogs are Iso...

  8. Epidemiology and Geographical Distribution of Enteric Protozoan Infections in Sydney, Australia

    PubMed Central

    Fletcher, Stephanie; Caprarelli, Graziella; Merif, Juan; Andresen, David; Hal, Sebastian Van; Stark, Damien; Ellis, John

    2014-01-01

    Background Enteric protozoa are associated with diarrhoeal illnesses in humans; however there are no recent studies on their epidemiology and geographical distribution in Australia. This study describes the epidemiology of enteric protozoa in the state of New South Wales and incorporates spatial analysis to describe their distribution. Design and methods Laboratory and clinical records from four public hospitals in Sydney for 910 patients, who tested positive for enteric protozoa over the period January 2007 - December 2010, were identified, examined and analysed. We selected 580 cases which had residence post code data available, enabling us to examine the geographic distribution of patients, and reviewed the clinical data of 252 patients to examine possible links between protozoa, demographic and clinical features. Results Frequently detected protozoa were Blastocystis spp. (57%), Giardia intestinalis (27%) and Dientamoeba fragilis (12%). The age distribution showed that the prevalence of protozoa decreased with age up to 24 years but increasing with age from 25 years onwards. The geographic provenance of the patients indicates that the majority of cases of Blastocystis (53.1%) are clustered in and around the Sydney City Business District, while pockets of giardiasis were identified in regional/rural areas. The distribution of cases suggests higher risk of protozoan infection may exist for some communities. Conclusions These findings provide useful information for policy makers to design and tailor interventions to target high risk communities. Follow-up investigation into the risk factors for giardiasis in regional/rural areas is needed. Significance for public health This research is significant since it provides the most recent epidemiological update on the common enteric protozoa affecting Australians. It reveals that enteric protozoa cause considerable disease burden in high risk city dwellers, and provides the evidence base for development of targeted interventions for their prevention and control in high risk populations. The prevalence of enteric protozoa in this metropolitan setting underscores that microorganisms do not respect borders and that a collaborative approach is needed to contain the global spread of infectious diseases. Incorporating spatial analysis is valuable in providing a compelling picture of the geographical distribution of these often neglected diseases. Local and State Public Health departments can use this information to support further inves- PMID:25343139

  9. Role of gregarine parasite Ascogregarina culicis (Apicomplexa: Lecudinidae) in the maintenance of Chikungunya virus in vector mosquito.

    PubMed

    Moury, D T; Singh, D K; Yadav, P; Gokhale, M D; Barde, P V; Narayan, N B; Thakare, J P; Mishra, A C; Shouche, Y S

    2003-01-01

    Ascogregarina culicis and Ascogregarina taiwanensis are common gregarine parasites of Aedes aegypti and Aedes albopictus mosquitoes, respectively. These mosquito species are also known to transmit dengue and Chikungunya viruses. The sporozoites of these parasites invade the midgut epithelial cells and develop intracellularly and extracellularly in the gut to complete their life cycles. The midgut is also the primary site for virus replication in the vector mosquitoes. Therefore, studies were carried out with a view to determine the possible role of these gregarines in the vertical transmission of dengue and Chikungunya viruses from larval to adult stage. Experiments were performed by exposing first instar mosquito larvae to suspensions containing parasite oocysts and viruses. Since Ascogregarina sporozoites invade the midgut of first instar larvae, the vertical transmission was determined by feeding the uninfected first instar larvae on the freshly prepared homogenates from mosquitoes, which were dually infected with viruses and the parasite oocysts. Similarly, the role of protozoan parasites in the vertical transmission of viruses was determined by exposing fresh first instar larvae to the dried pellets of homogenates prepared from the mosquitoes dually infected with viruses and the parasite oocysts. Direct vertical transmission and the vertical transmission of CHIK virus through the oocyst of the parasites were observed in the case of Ae. aegypti mosquitoes. It is suggested that As. culicis may have an important role in the maintenance of CHIK virus during the inter-epidemic period. PMID:14563178

  10. Physiology and phylogeny of the candidate phylum "Atribacteria" (formerly OP9/JS1) inferred from single-cell genomics and metagenomics

    NASA Astrophysics Data System (ADS)

    Dodsworth, J. A.; Murugapiran, S.; Blainey, P. C.; Nobu, M.; Rinke, C.; Schwientek, P.; Gies, E.; Webster, G.; Kille, P.; Weightman, A.; Liu, W. T.; Hallam, S.; Tsiamis, G.; Swingley, W.; Ross, C.; Tringe, S. G.; Chain, P. S.; Scholz, M. B.; Lo, C. C.; Raymond, J.; Quake, S. R.; Woyke, T.; Hedlund, B. P.

    2014-12-01

    Single-cell sequencing and metagenomics have extended the genomics revolution to yet-uncultivated microorganisms and provided insights into the coding potential of this so-called "microbial dark matter", including microbes belonging candidate phyla with no cultivated representatives. As more datasets emerge, comparison of individual genomes from different lineages and habitats can provide insight into the phylogeny, conserved features, and potential metabolic diversity of candidate phyla. The candidate bacterial phylum OP9 was originally found in Obsidian Pool, Yellowstone National Park, and it has since been detected in geothermal springs, petroleum reservoirs, and engineered thermal environments worldwide. JS1, another uncultivated bacterial lineage affiliated with OP9, is often abundant in marine sediments associated with methane hydrates, hydrocarbon seeps, and on continental margins and shelves, and is found in other non-thermal marine and subsurface environments. The phylogenetic relationship between OP9, JS1, and other Bacteria has not been fully resolved, and to date no axenic cultures from these lineages have been reported. Recently, 31 single amplified genomes (SAGs) from six distinct OP9 and JS1 lineages have been obtained using flow cytometric and microfluidic techniques. These SAGs were used to inform metagenome binning techniques that identified OP9/JS1 sequences in several metagenomes, extending genomic coverage in three of the OP9 and JS1 lineages. Phylogenomic analyses of these SAG and metagenome bin datasets suggest that OP9 and JS1 constitute a single, deeply branching phylum, for which the name "Atribacteria" has recently been proposed. Overall, members of the "Atribacteria" are predicted to be heterotrophic anaerobes without the capacity for respiration, with some lineages potentially specializing in secondary fermentation of organic acids. A set of signature "Atribacteria" genes was tentatively identified, including components of a bacterial microcompartments gene cluster that may be involved in carbohydrate catabolism. The "Atribacteria" may play important roles in biomass processing in anaerobic geothermal and subsurface environments.

  11. Protozoan Fauna and Abundance in Aeration Tanks of Three Municipal Wastewater Treatment Plants in the Eastern Cape Province of South Africa

    NASA Astrophysics Data System (ADS)

    Sibewu, M.; Momba, M. N. B.; Okoh, A. L.

    This study focuses on the assessment of the protozoan fauna and abundance in the mixed liquors of aeration tanks of the three municipal wastewater treatment plants located in Fort Beaufort, Dimbaza and East London in the Eastern Cape Province of South Africa and their implication to the production of effluents of good quality. The samples were collected between September and December 2005 and protozoa species were identified by direct microscopic observations at x400 magnification by comparison with existing protozoa gallery collections. A total of 68 protozoan genera made up of 44 ciliates, 16 flagellates and 8 others were identified in wastewater treatment plants. Although in all aerobic zones the average density of ciliates was 104 cells mL-1, which indicated that these plants were able to produce clear effluent of good quality, a better performance was found in Dimbaza and East London, which had total protozoan genera of 27 and 26, respectively.

  12. Selective Inhibitors of Protozoan Protein N-myristoyltransferases as Starting Points for Tropical Disease Medicinal Chemistry Programs

    PubMed Central

    Bell, Andrew S.; Mills, James E.; Williams, Gareth P.; Brannigan, James A.; Wilkinson, Anthony J.; Parkinson, Tanya; Leatherbarrow, Robin J.; Tate, Edward W.; Holder, Anthony A.; Smith, Deborah F.

    2012-01-01

    Inhibition of N-myristoyltransferase has been validated pre-clinically as a target for the treatment of fungal and trypanosome infections, using species-specific inhibitors. In order to identify inhibitors of protozoan NMTs, we chose to screen a diverse subset of the Pfizer corporate collection against Plasmodium falciparum and Leishmania donovani NMTs. Primary screening hits against either enzyme were tested for selectivity over both human NMT isoforms (Hs1 and Hs2) and for broad-spectrum anti-protozoan activity against the NMT from Trypanosoma brucei. Analysis of the screening results has shown that structure-activity relationships (SAR) for Leishmania NMT are divergent from all other NMTs tested, a finding not predicted by sequence similarity calculations, resulting in the identification of four novel series of Leishmania-selective NMT inhibitors. We found a strong overlap between the SARs for Plasmodium NMT and both human NMTs, suggesting that achieving an appropriate selectivity profile will be more challenging. However, we did discover two novel series with selectivity for Plasmodium NMT over the other NMT orthologues in this study, and an additional two structurally distinct series with selectivity over Leishmania NMT. We believe that release of results from this study into the public domain will accelerate the discovery of NMT inhibitors to treat malaria and leishmaniasis. Our screening initiative is another example of how a tripartite partnership involving pharmaceutical industries, academic institutions and governmental/non-governmental organisations such as Medical Research Council and Wellcome Trust can stimulate research for neglected diseases. PMID:22545171

  13. Spironucleus meleagridis, an enteric diplomonad protozoan of cockatiels (Nymphicus hollandicus): preliminary molecular characterization and association with clinical disease.

    PubMed

    Levy, M G; Powers, L V; Gore, K C; Marr, H S

    2015-03-15

    A flagellated enteric diplomonad protozoan consistent with Spironucleus meleagridis (formerly Hexamita meleagridis) associated with gastrointestinal disease and mortality in psittacine birds including cockatiels (Nymphicus hollandicus) has been sporadically described in the literature. However, molecular characterization of psittacine protozoal isolates had not yet been performed. The 16S rRNA gene from a protozoan persistently shed in the feces in a small group of cockatiels demonstrated a 98% molecular identity with S. meleagridis isolated from turkeys. Based on these sequence data, a diagnostic PCR assay was developed to detect the presence of S. meleagridis. Nineteen privately owned pet cockatiels from unrelated households were clinically evaluated. All birds microscopically positive for this organism were PCR positive, with several additional birds microscopically negative but PCR positive. Many of the birds identified as positive for S. meleagridis by fecal PCR had signs of gastrointestinal disease such as diarrhea, soft feces, and melena, whereas none of the birds that tested negative had gastrointestinal signs. Examination of feces from two unrelated cockatiel breeding facilities revealed 70% and 86% PCR positive rates. Prevalence of infection and incidence of clinical disease, including factors that lead to clinical manifestation such as viral, bacterial, or mycotic coinfections, are not yet known and warrant further study, but spironucleosis is likely an under-recognized disease in cockatiels. PMID:25595477

  14. Seasonal incidence of protozoan parasites of the black tiger shrimp (Penaeus monodon) of Sundarbans, West Bengal, India.

    PubMed

    Chakraborti, Jayati; Bandyapadhyay, Probir K

    2011-06-01

    There is a delicate balance between the host, pathogen and environment. Aquatic organisms, including shellfish, respond directly to climatic changes in their biological environment as their metabolic processes are influenced by temperature, salinity, and oxygen levels. Certain environmental conditions are more conducive to diseases than others among which water temperature is significantly associated with disease outbreak. The present study showed that Peneaus monodon of Sundarbans serve as a host for many protozoan parasites and epibionts including ciliates, gregarines and microsporidia. The protozoan parasites also require a particular environmental condition for their maximum growth and survival. The intensity of infection significantly increases with rise in temperature (P < 0.05) following a definite trend but no significant relationship between infection rate of ciliates and pH of water. In case of gregarine parasites significance (P < 0.05) exists among infection rate and temperature as well as pH of the farm water. Microsporidian parasites do not follow any significant seasonal trend in infecting the host P. monodon. PMID:22654317

  15. The Toxoplasma Dense Granule Proteins GRA17 and GRA23 Mediate the Movement of Small Molecules between the Host and the Parasitophorous Vacuole.

    PubMed

    Gold, Daniel A; Kaplan, Aaron D; Lis, Agnieszka; Bett, Glenna C L; Rosowski, Emily E; Cirelli, Kimberly M; Bougdour, Alexandre; Sidik, Saima M; Beck, Josh R; Lourido, Sebastian; Egea, Pascal F; Bradley, Peter J; Hakimi, Mohamed-Ali; Rasmusson, Randall L; Saeij, Jeroen P J

    2015-05-13

    Toxoplasma gondii is a protozoan pathogen in the phylum Apicomplexa that resides within an intracellular parasitophorous vacuole (PV) that is selectively permeable to small molecules through unidentified mechanisms. We have identified GRA17 as a Toxoplasma-secreted protein that localizes to the parasitophorous vacuole membrane (PVM) and mediates passive transport of small molecules across the PVM. GRA17 is related to the putative Plasmodium translocon protein EXP2 and conserved across PV-residing Apicomplexa. The PVs of GRA17-deficient parasites have aberrant morphology, reduced permeability to small molecules, and structural instability. GRA17-deficient parasites proliferate slowly and are avirulent in mice. These GRA17-deficient phenotypes are rescued by complementation with Plasmodium EXP2. GRA17 functions synergistically with a related protein, GRA23. Exogenous expression of GRA17 or GRA23 alters the membrane conductance properties of Xenopus oocytes in a manner consistent with a large non-selective pore. Thus, GRA17 and GRA23 provide a molecular basis for PVM permeability and nutrient access. PMID:25974303

  16. Evidence for the bacterial origin of genes encoding fermentation enzymes of the amitochondriate protozoan parasite Entamoeba histolytica.

    PubMed Central

    Rosenthal, B; Mai, Z; Caplivski, D; Ghosh, S; de la Vega, H; Graf, T; Samuelson, J

    1997-01-01

    Entamoeba histolytica is an amitochondriate protozoan parasite with numerous bacterium-like fermentation enzymes including the pyruvate:ferredoxin oxidoreductase (POR), ferredoxin (FD), and alcohol dehydrogenase E (ADHE). The goal of this study was to determine whether the genes encoding these cytosolic E. histolytica fermentation enzymes might derive from a bacterium by horizontal transfer, as has previously been suggested for E. histolytica genes encoding heat shock protein 60, nicotinamide nucleotide transhydrogenase, and superoxide dismutase. In this study, the E. histolytica por gene and the adhE gene of a second amitochondriate protozoan parasite, Giardia lamblia, were sequenced, and their phylogenetic positions were estimated in relation to POR, ADHE, and FD cloned from eukaryotic and eubacterial organisms. The E. histolytica por gene encodes a 1,620-amino-acid peptide that contained conserved iron-sulfur- and thiamine pyrophosphate-binding sites. The predicted E. histolytica POR showed fewer positional identities to the POR of G. lamblia (34%) than to the POR of the enterobacterium Klebsiella pneumoniae (49%), the cyanobacterium Anabaena sp. (44%), and the protozoan Trichomonas vaginalis (46%), which targets its POR to anaerobic organelles called hydrogenosomes. Maximum-likelihood, neighbor-joining, and parsimony analyses also suggested as less likely E. histolytica POR sharing more recent common ancestry with G. lamblia POR than with POR of bacteria and the T. vaginalis hydrogenosome. The G. lamblia adhE encodes an 888-amino-acid fusion peptide with an aldehyde dehydrogenase at its amino half and an iron-dependent (class 3) ADH at its carboxy half. The predicted G. lamblia ADHE showed extensive positional identities to ADHE of Escherichia coli (49%), Clostridium acetobutylicum (44%), and E. histolytica (43%) and lesser identities to the class 3 ADH of eubacteria and yeast (19 to 36%). Phylogenetic analyses inferred a closer relationship of the E. histolytica ADHE to bacterial ADHE than to the G. lamblia ADHE. The 6-kDa FD of E. histolytica and G. lamblia were most similar to those of the archaebacterium Methanosarcina barkeri and the delta-purple bacterium Desulfovibrio desulfuricans, respectively, while the 12-kDa FD of the T. vaginalis hydrogenosome was most similar to the 12-kDa FD of gamma-purple bacterium Pseudomonas putida. E. histolytica genes (and probably G. lamblia genes) encoding fermentation enzymes therefore likely derive from bacteria by horizontal transfer, although it is not clear from which bacteria these amebic genes derive. These are the first nonorganellar fermentation enzymes of eukaryotes implicated to have derived from bacteria. PMID:9171424

  17. Characterization of a Defensin from the Sand Fly Phlebotomus duboscqi Induced by Challenge with Bacteria or the Protozoan Parasite Leishmania major

    Microsoft Academic Search

    Nathalie Boulanger; Carl Lowenberger; Petr Volf; Raul Ursic; Lucie Sigutova; Laurence Sabatier; Milena Svobodova; Stephen M. Beverley; Gerald Spath; Reto Brun; Bernard Pesson; Philippe Bulet

    2004-01-01

    Antimicrobial peptides are major components of the innate immune response of epithelial cells. In insect vectors, these peptides may play a role in the control of gut pathogens. We have analyzed antimicrobial peptides produced by the sand fly Phlebotomus duboscqi, after challenge by injected bacteria or feeding with bacteria or the protozoan parasite Leishmania major. A new hemolymph peptide with

  18. The Intestinal Protozoan Parasite Entamoeba histolytica Contains 20 Cysteine Protease Genes, of Which Only a Small Subset Is Expressed during In Vitro Cultivation

    Microsoft Academic Search

    Iris Bruchhaus; Brendan J. Loftus; N. Hall; E. Tannich

    2003-01-01

    Cysteine proteases are known to be important pathogenicity factors of the protozoan parasite Entamoeba histolytica. So far, a total of eight genes coding for cysteine proteases have been identified in E. histolytica, two of which are absent in the closely related nonpathogenic species E. dispar. However, present knowledge is restricted to enzymes expressed during in vitro cultivation of the parasite,

  19. Isolation of a Protozoan Parasite Genetically Related to the Insect Trypanosomatid Herpetomonas samuelpessoai from a Human Immunodeficiency Virus-Positive Patient?

    PubMed Central

    Morio, Florent; Reynes, Jacques; Dollet, Michel; Pratlong, Francine; Dedet, Jean-Pierre; Ravel, Christophe

    2008-01-01

    Severely immunocompromised human immunodeficiency virus (HIV) patients can develop various opportunistic infections due to bacteria, viruses, fungi, or protozoa. Here we report the first isolation of a flagellated protozoan genetically closely related to Herpetomonas samuelpessoai, which is usually a parasite of insects, from the blood of an HIV-infected patient. PMID:18832132

  20. Toll-Like Receptor 4 Contributes to Efficient Control of Infection with the Protozoan Parasite Leishmania major

    PubMed Central

    Kropf, Pascale; Freudenberg, Marina A.; Modolell, Manuel; Price, Helen P.; Herath, Shanti; Antoniazi, Simone; Galanos, Chris; Smith, Deborah F.; Müller, Ingrid

    2004-01-01

    The essential role of Toll-like receptors (TLR) in innate immune responses to bacterial pathogens is increasingly recognized, but very little is known about the role of TLRs in host defense against infections with eukaryotic pathogens. For the present study, we investigated whether TLRs contribute to the innate and acquired immune response to infection with the intracellular protozoan parasite Leishmania major. Our results show that TLR4 contributes to the control of parasite growth in both phases of the immune response. We also addressed the mechanism that results in killing or growth of the intracellular parasites. Control of parasite replication correlates with the early induction of inducible nitric oxide synthase in TLR4-competent mice, whereas increased parasite survival in host cells from TLR4-deficient mice correlates with a higher activity of arginase, an enzyme known to promote parasite growth. This is the first study showing that TLR4 contributes to the effective control of Leishmania infection in vivo. PMID:15039311

  1. THE PROTOZOAN INOSITOL PHOSPHORYLCERAMIDE SYNTHASE: A NOVEL DRUG TARGET WHICH DEFINES A NEW CLASS OF SPHINGOLIPID SYNTHASE

    PubMed Central

    Denny, Paul W.; Shams-Eldin, Hosam; Price, Helen. P.; Smith, Deborah F.; Schwarz, Ralph T.

    2007-01-01

    Sphingolipids are ubiquitous and essential components of eukaryotic membranes, particularly the plasma membrane. The biosynthetic pathway for the formation of these lipid species is conserved up to the formation of sphinganine. However, a divergence is apparent in the synthesis of complex sphingolipids. In animal cells, ceramide is a substrate for sphingomyelin (SM) production via the enzyme SM synthase. In contrast, fungi utilise phytoceramide in the synthesis of inositol phosphorylceramide (IPC) catalysed by IPC synthase. Due to the absence of a mammalian equivalent, this essential enzyme represents an attractive target for anti-fungal compounds. In common with the fungi, the kinetoplastid protozoa (and higher plants) synthesize IPC rather than SM. However, orthologues of the gene believed to encode the fungal IPC synthase (AUR1) are not readily identified in the complete genome databases of these species. By utilising bioinformatic and functional genetic approaches, we have isolated a functional orthologue of AUR1 in the kinetoplastids, causative agents of a range of important human diseases. Expression of this gene in a mammalian cell line led to the synthesis of an IPC-like species strongly indicating that IPC synthase activity is reconstituted. Furthermore the gene product can be specifically inhibited by an anti-fungal targeting IPC synthase. We propose that the kinetoplastid AUR1 functional orthologue encodes an enzyme which defines a new class of protozoan sphingolipid synthase. The identification and characterisation of the protozoan IPC synthase, an enzyme with no mammalian equivalent, will raise the possibility of developing anti-protozoal drugs with minimal toxic side-affects. PMID:16861742

  2. Heterogeneity in the Attachment and Uptake Mechanisms of the Legionnaires’ Disease Bacterium, Legionella pneumophila, by Protozoan Hosts

    PubMed Central

    Harb, Omar S.; Venkataraman, Chandrasekar; Haack, Bradley J.; Gao, Lian-Yong; Kwaik, Yousef Abu

    1998-01-01

    Invasion and intracellular replication of Legionella pneumophila within protozoa in the environment plays a major role in the transmission of Legionnaires’ disease. Intracellular replication of L. pneumophila within protozoa occurs in a rough endoplasmic reticulum (RER)-surrounded phagosome (Y. Abu Kwaik, Appl. Environ. Microbiol. 62:2022–2028, 1996). Since the subsequent fate of many intracellular pathogens is determined by the route of entry, we compared the mechanisms of attachment and subsequent uptake of L. pneumophila by the two protozoa Hartmannella vermiformis and Acanthamoeba polyphaga. Our data provide biochemical and genetic evidence that the mechanisms of attachment and subsequent uptake of L. pneumophila by the two protozoan hosts are, in part, different. First, uptake of L. pneumophila by H. vermiformis is completely blocked by the monovalent sugars galactose and N-acetyl-d-galactosamine, but these sugars partially blocked A. polyphaga. Second, attachment of L. pneumophila to H. vermiformis is associated with a time-dependent and reversible tyrosine dephosphorylation of multiple host proteins. In contrast, only a slight dephosphorylation of a 170-kDa protein of A. polyphaga is detected upon infection. Third, synthesis of H. vermiformis proteins but not of A. polyphaga proteins is required for uptake of L. pneumophila. Fourth, we have identified L. pneumophila mutants that are severely defective in attachment to A. polyphaga but which exhibit minor reductions in attachment to H. vermiformis and, thus, provide a genetic basis for the difference in mechanisms of attachment to both protozoa. The data indicate a remarkable adaptation of L. pneumophila to attach and invade different protozoan hosts by different mechanisms, yet invasion is followed by a remarkably similar intracellular replication within a RER-surrounded phagosome and subsequent killing of the host cell. PMID:9435069

  3. Revision of the genus Torogregarina and description of Torogregarina sphinx n. sp. (Apicomplexa: Eugregarinida) from a Missouri river bank beetle, Bembidion laevigatum (Coleoptera: Carabidae), in southeastern Nebraska.

    PubMed

    Clopton, R E

    1998-08-01

    Torogregarina is revised to clarify the nature of the epimerite-protomerite complex and the method of gametocyst dehiscence, removed from the family Gregarinidae, and placed among the Hirmocystidae. Torogregarina sphinx n. sp. (Apicomplexa: Eugregarinida) is described from Bembidion laevigatum (Coleoptera: Carabidae) collected along the Missouri River near Peru, Nemaha County, Nebraska. Measurements are means in micrometers. Association is precocious and caudofrontal. Primite epimerite depressed ovoid and persistent through syzygy; length 25.2, width 41.0. Protomerite a high toroid collar between epimerite and deutomerite; length 13.5, width 35.4. Deutomerite obovoid; length 137.3, width 90.7. Total length including epimerite 172.2. Satellite epimerite protomerite complex concentrically formed by a depressed ovoid epimerite within a transversely oblong protomerite, the protruding dome of the epimerite fitting into a posterior depression on the primite and the transverse anterior margin of the protomerite mating with the posterior margin of the primite to form the syzygial junction; length 25.0, width 48.8. Deutomerite obovoid; length 113.5, width 63.5. Total length 138.6. Gametocysts roughly spherical; diameter 142.9. Gametocysts mature and dehisce by simple rupture, extruding oocysts in a single mass without an epispore packet. Oocysts axially symmetric, dolioform in dorsal aspect, concavoconcave in transverse plane, uniform in size and shape; length 5.2, terminal width 2.4, equatorial width 3.1. PMID:9714218

  4. Ditrypanocystis sp. (Apicomplexa, Gregarinia, Selenidiidae): the mode of survival in the gut of Enchytraeus albidus (Annelida, Oligochaeta, Enchytraeidae) is close to that of the coccidian genus Cryptosporidium.

    PubMed

    Butaeva, F; Paskerova, G; Entzeroth, R

    2006-01-01

    A selenid gregarine Ditrypanocystis sp. (Apicomplexa, Gregarinia, Selenidiidae), harboring the gut lumen of the oligochaete Enchytraeus albidus, was studied by light and electron microscopy. The trophozoite of Ditrypanocystis sp. is attached to the gut wall with its apical end to be anchored eventually between enterocytes in the crypts. Simultaneously, between the surfaces of the parasite and the host cell a peculiar contact is formed made of membranous channels and vesicles of unknown origin, the host cell surface in the contact area lacking cilia. The trophozoite becomes progressively enclosed within a parasitophorous vacuole made of layers of fused ciliar membranes of enterocytes. The fused cilia may be a source of membranes lining channels and vesicles of the contact area. Such a mode of parasitophorous arrangements has never been described before for gregarines, however, it bears a some likeness with that of the coccidian genus Cryptosporidium (similarity and differences being discussed). With regard to some molecular phylogeny constructions, claiming the "sister" relationship between gregarines and the coccidian genus Cryptosporidium (Carreno et al., 1999; Leander et al., 2003), this common feature in host-parasite relationships enabled us to put forward an idea of a possible evolutionary route from extracellularity of gregarines to intracellularity of coccidia, as exemplified by species of Cryptosporidium. PMID:17147263

  5. Gregarines on a diet: the effects of host starvation on Gregarina confusa Janovy et al., 2007 (Apicomplexa: Eugregarinida) in Tribolium destructor Uyttenboogaart, 1933 (Coleoptera: Tenebrionidae) larvae.

    PubMed

    Schreurs, Jodi; Janovy, John

    2008-06-01

    This study was designed to explore the nutritional relationship between Gregarina confusa (Apicomplexa: Eugregarinida) parasites and its coleopteran host, Tribolium destructor, by measuring the cytoplasmic density of gregarines in continuously fed larvae, starved larvae, and larvae refed after starvation. Cultures were maintained in a standard media (whole wheat flour:commercial wheat germ:yeast [30:10:1]). Larvae from control and experimental groups were dissected daily for 3 days then allowed to feed or starve for an additional 3 days. On day 6, the remaining experimental larvae were divided and placed into 2 groups; 1 group remained starved while larvae from the second group were fed a Wheaties flake. Photographs were taken of the parasites daily and analyzed using ScionImage. Gregarines from starved larvae were significantly longer and skinnier than those from fed controls, and there was also a significant difference between gregarine deutomerite cytoplasmic densities. Parasites from refed larvae regained cytoplasmic density within 24 hr and showed morphological similarities to those from fed larvae. This study shows that the Tribolium destructor-Gregarina confusa relationship can be manipulated easily through alterations of host diet and thus is an excellent model for use in the study of chemical relationships between parasites and their hosts. PMID:18605781

  6. Chthoniobacter flavus gen. nov., sp. nov., the First Pure-Culture Representative of Subdivision Two, Spartobacteria classis nov., of the Phylum Verrucomicrobia

    PubMed Central

    Sangwan, Parveen; Chen, Xiaolei; Hugenholtz, Philip; Janssen, Peter H.

    2004-01-01

    The phylum Verrucomicrobia is increasingly recognized as an environmentally significant group of bacteria, particularly in soil habitats. At least six subdivisions of the Verrucomicrobia are resolved by comparative analysis of 16S rRNA genes, mostly obtained directly from environmental samples. To date, only two of these subdivisions (1 and 4) have characterized pure-culture representatives. We have isolated and characterized the first known pure-culture representative of subdivision 2. Strain Ellin428 is an aerobic heterotrophic bacterium that is able to grow with many of the saccharide components of plant biomass but does not grow with amino acids or organic acids other than pyruvate. Cells are yellow, rod-shaped, nonmotile, and gram-stain negative, and they contain peptidoglycan with direct cross-linkages of the A1? meso-Dpm type. The isolate grows well at 25°C on a variety of standard biological media, including some used in the routine cultivation of bacteria from soil. The pH range for growth is 4.0 to 7.0. Low levels of menaquinones MK-10 and MK-11 were detected. The major cellular fatty acids are C14:0, a-C15:0, C16:1?7c, and/or 2OH i-C15:0, and C16:0. The G+C content of the genomic DNA is 61 mol%. We propose a new genus and species, Chthoniobacter flavus gen. nov., sp. nov., with isolate Ellin428 as the type strain, and a new class for the subdivision to which it belongs, Spartobacteria classis nov. Environmental sequences indicate that the class Spartobacteria is largely represented by globally distributed, abundant, and active soil bacteria. PMID:15466527

  7. Synthesis, Solution Structure, and Phylum Selectivity of a Spider ?-Toxin That Slows Inactivation of Specific Voltage-gated Sodium Channel Subtypes*

    PubMed Central

    Yamaji, Nahoko; Little, Michelle J.; Nishio, Hideki; Billen, Bert; Villegas, Elba; Nishiuchi, Yuji; Tytgat, Jan; Nicholson, Graham M.; Corzo, Gerardo

    2009-01-01

    Magi 4, now renamed ?-hexatoxin-Mg1a, is a 43-residue neurotoxic peptide from the venom of the hexathelid Japanese funnel-web spider (Macrothele gigas) with homology to ?-hexatoxins from Australian funnel-web spiders. It binds with high affinity to receptor site 3 on insect voltage-gated sodium (NaV) channels but, unlike ?-hexatoxins, does not compete for the related site 3 in rat brain despite being previously shown to be lethal by intracranial injection. To elucidate differences in NaV channel selectivity, we have undertaken the first characterization of a peptide toxin on a broad range of mammalian and insect NaV channel subtypes showing that ?-hexatoxin-Mg1a selectively slows channel inactivation of mammalian NaV1.1, NaV1.3, and NaV1.6 but more importantly shows higher affinity for insect NaV1 (para) channels. Consequently, ?-hexatoxin-Mg1a induces tonic repetitive firing of nerve impulses in insect neurons accompanied by plateau potentials. In addition, we have chemically synthesized and folded ?-hexatoxin-Mg1a, ascertained the bonding pattern of the four disulfides, and determined its three-dimensional solution structure using NMR spectroscopy. Despite modest sequence homology, we show that key residues important for the activity of scorpion ?-toxins and ?-hexatoxins are distributed in a topologically similar manner in ?-hexatoxin-Mg1a. However, subtle differences in the toxin surfaces are important for the novel selectivity of ?-hexatoxin-Mg1a for certain mammalian and insect NaV channel subtypes. As such, ?-hexatoxin-Mg1a provides us with a specific tool with which to study channel structure and function and determinants for phylum- and tissue-specific activity. PMID:19592486

  8. Temporal population dynamics of dinoflagellate Prorocentrum minimum in a semi-enclosed mariculture pond and its relationship to environmental factors and protozoan grazers

    NASA Astrophysics Data System (ADS)

    Xu, Henglong; Min, Gi-Sik; Choi, Joong-Ki; Zhu, Mingzhuang; Jiang, Yong; Al-Rasheid, Khaled A. S.

    2010-01-01

    The ecological processes and interrelationships between protists, either autotrophic or heterotrophic, and environmental factors in mariculture ponds are largely unknown. This study investigated the temporal dynamics of potentially harmful dinoflagellate, Prorocentrum minimum (Pavillard) Schiller, and its relationship to physico-chemical factors and protozoan grazers over a complete cycle in a semi-enclosed shrimp-farming pond near Qingdao, Northern China. P. minimum occurred frequently in low numbers from June to August, followed by a sharp increase from the middle of August, reaching a single maximum peak value of 2.2×105 cells L-1 in October. Temporal variation in abundance was positively correlated with dissolved nitrogen, but showed a significant inverse relationship to abundance of the dominant ciliates, Tintinnopsis lohmanni and Askenasia stellaris. The results provide statistical evidence that the number of P. minimum increased with increasing nitrogen, and the suppression or shortening of algal bloom may be associated with protozoan grazers, such as Tintinnopsis lohmanni, in mariculture ponds.

  9. Monarch butterflies (Danaus plexippus) are commonly infected by the protozoan parasite, Ophryocystis elektroschirra. This study examined the effect of infection on monarch mating contests and mating success. Monarch mating behavior involves males chasing

    E-print Network

    Gittleman, John

    Monarch butterflies (Danaus plexippus) are commonly infected by the protozoan parasite that because infected monarchs are often in poorer condition than healthy butterflies, and mating less often than healthy butterflies. This study was initiated using healthy and experimentally infected

  10. Glycosylinositol-phosphoceramide in the free-living protozoan Paramecium primaurelia: modification of core glycans by mannosyl phosphate.

    PubMed Central

    Azzouz, N; Striepen, B; Gerold, P; Capdeville, Y; Schwarz, R T

    1995-01-01

    Glycolipids synthesized in a cell-free system prepared from the free-living protozoan Paramecium primaurelia and labelled with [3H]mannose and [3H]glucosamine using GDP-[3H]mannose and UDP-[3H]N-acetyl glucosamine, respectively, were identified and structurally characterized as glycosylinositol-phosphoceramides (GIP-ceramides). The ceramide-based lipid was also found in the GIP membrane anchor of the G surface antigen of P.primaurelia, strain 156. Using a combination of in vitro labelling with GDP-[3H]mannose and in vivo labelling with 33P, we found that the core glycans of the P.primaurelia GIP-ceramides were substituted with an acid-labile modification identified as mannosyl phosphate. The modification of the glycosylinositol-phospholipid core glycan by mannosyl phosphate has not been described to date in other organisms. The biosynthesis of GIP-ceramide intermediates in P.primaurelia was studied by a pulse-chase analysis. Their structural characterization is reported. We propose the following structure for the putative GIP-ceramide membrane anchor precursor of P.primaurelia surface proteins: ethanolamine phosphate-6Man-alpha 1-2Man-alpha 1-6Man-(mannosyl phosphate)-alpha 1-4glucosamine-inositol-phosphoceramide. PMID:7556085

  11. Biochemical and Kinetic Characterization of the Recombinant ADP-Forming Acetyl Coenzyme A Synthetase from the Amitochondriate Protozoan Entamoeba histolytica

    PubMed Central

    Jones, Cheryl P.

    2014-01-01

    Entamoeba histolytica, an amitochondriate protozoan parasite that relies on glycolysis as a key pathway for ATP generation, has developed a unique extended PPi-dependent glycolytic pathway in which ADP-forming acetyl-coenzyme A (CoA) synthetase (ACD; acetate:CoA ligase [ADP-forming]; EC 6.2.1.13) converts acetyl-CoA to acetate to produce additional ATP and recycle CoA. We characterized the recombinant E. histolytica ACD and found that the enzyme is bidirectional, allowing it to potentially play a role in ATP production or in utilization of acetate. In the acetate-forming direction, acetyl-CoA was the preferred substrate and propionyl-CoA was used with lower efficiency. In the acetyl-CoA-forming direction, acetate was the preferred substrate, with a lower efficiency observed with propionate. The enzyme can utilize both ADP/ATP and GDP/GTP in the respective directions of the reaction. ATP and PPi were found to inhibit the acetate-forming direction of the reaction, with 50% inhibitory concentrations of 0.81 ± 0.17 mM (mean ± standard deviation) and 0.75 ± 0.20 mM, respectively, which are both in the range of their physiological concentrations. ATP and PPi displayed mixed inhibition versus each of the three substrates, acetyl-CoA, ADP, and phosphate. This is the first example of regulation of ACD enzymatic activity, and possible roles for this regulation are discussed. PMID:25303954

  12. Cysteine Protease-Binding Protein Family 6 Mediates the Trafficking of Amylases to Phagosomes in the Enteric Protozoan Entamoeba histolytica

    PubMed Central

    Furukawa, Atsushi; Nakada-Tsukui, Kumiko

    2013-01-01

    Phagocytosis plays a pivotal role in nutrient acquisition and evasion from the host defense systems in Entamoeba histolytica, the intestinal protozoan parasite that causes amoebiasis. We previously reported that E. histolytica possesses a unique class of a hydrolase receptor family, designated the cysteine protease-binding protein family (CPBF), that is involved in trafficking of hydrolases to lysosomes and phagosomes, and we have also reported that CPBF1 and CPBF8 bind to cysteine proteases or ?-hexosaminidase ?-subunit and lysozymes, respectively. In this study, we showed by immunoprecipitation that CPBF6, one of the most highly expressed CPBF proteins, specifically binds to ?-amylase and ?-amylase. We also found that CPBF6 is localized in lysosomes, based on immunofluorescence imaging. Immunoblot and proteome analyses of the isolated phagosomes showed that CPBF6 mediates transport of amylases to phagosomes. We also demonstrated that the carboxyl-terminal cytosolic region of CPBF6 is engaged in the regulation of the trafficking of CPBF6 to phagosomes. Our proteome analysis of phagosomes also revealed new potential phagosomal proteins. PMID:23509141

  13. Glycoproteins, antigens, and regulation of complement activation on the surface of the protozoan parasite Trypanosoma lewisi: implications for immune evasion

    SciTech Connect

    Sturtevant, J.E.

    1985-01-01

    The surface antigens and glycoproteins of the rat parasitic protozoan, Trypanosoma lewisi were characterized. Radioiodination with /sup 125/I identified 10 out of more 40 polypeptides separated on sodium dodecyl sulfate polyacrylamide gel electrophoresis. All of these components were identified as glycoproteins by peroxidase-conjugated Conconavalin A (HR-Con A) lectin affinoblotting. This analysis detected that quantitative but not qualitative changes occurred during infection. Localization of most of the reactive determinants was indicated by immunoblotting extracts of radioiodinated T. lewisi. Changes in the antigenicity as related to survival in the host are discussed. The presence of IgG and IgM on the surface of T. lewisi isolated from intact and ..gamma..-irradiated rats (irr.) and that determinants bind Ig from uninfected rat sera (NRS) was indicated by flow cytometric analysis. Immunoblotting identified the major NRS IgG binding component as the 74 kd surface glycoprotein. Complement component C3 deposition during infection was indicated by flow cytometric analysis and immunoblotting. Incubation of intact T. lewisi with normal human sera indicated that C3, C5, and factor B deposition was Mg/sup 2 +/ dependent, Ca/sup 2 +/ independent and deposited C3 was rapidly processed to hemolytically inactive fragments. Radioiodination of intact and protease T. lewisi after cultivation identified three components which correlate with resistance to lysis. This suggests that surface moieties on intact T. lewisi modulate host complement activity by restricting C3/C5 convertase activity.

  14. Strength in numbers: high parasite burdens increase transmission of a protozoan parasite of monarch butterflies (Danaus plexippus).

    PubMed

    de Roode, Jacobus C; Chi, Jean; Rarick, Rachel M; Altizer, Sonia

    2009-08-01

    Parasites often produce large numbers of offspring within their hosts. High parasite burdens are thought to be important for parasite transmission, but can also lower host fitness. We studied the protozoan Ophryocystis elektroscirrha, a common parasite of monarch butterflies (Danaus plexippus), to quantify the benefits of high parasite burdens for parasite transmission. This parasite is transmitted vertically when females scatter spores onto eggs and host plant leaves during oviposition; spores can also be transmitted between mating adults. Monarch larvae were experimentally infected and emerging adult females were mated and monitored in individual outdoor field cages. We provided females with fresh host plant material daily and quantified their lifespan and lifetime fecundity. Parasite transmission was measured by counting the numbers of parasite spores transferred to eggs and host plant leaves. We also quantified spores transferred from infected females to their mating partners. Infected monarchs had shorter lifespans and lower lifetime fecundity than uninfected monarchs. Among infected females, those with higher parasite loads transmitted more parasite spores to their eggs and to host plant leaves. There was also a trend for females with greater parasite loads to transmit more spores to their mating partners. These results demonstrate that high parasite loads on infected butterflies confer a strong fitness advantage to the parasite by increasing between-host transmission. PMID:19418070

  15. 2-acylamino-5-nitro-1,3-thiazoles: preparation and in vitro bioevaluation against four neglected protozoan parasites.

    PubMed

    Nava-Zuazo, Carlos; Chávez-Silva, Fabiola; Moo-Puc, Rosa; Chan-Bacab, Manuel Jesús; Ortega-Morales, Benjamín Otto; Moreno-Díaz, Hermenegilda; Díaz-Coutiño, Daniel; Hernández-Núñez, Emanuel; Navarrete-Vázquez, Gabriel

    2014-03-01

    The 2-acylamino-5-nitro-1,3-thiazole derivatives (1-14) were prepared using a one step reaction. All compounds were tested in vitro against four neglected protozoan parasites (Giardia intestinalis, Trichomonas vaginalis, Leishmania amazonensis and Trypanosoma cruzi). Acetamide (9), valeroylamide (10), benzamide (12), methylcarbamate (13) and ethyloxamate (14) derivatives were the most active compounds against G. intestinalis and T. vaginalis, showing nanomolar inhibition. Compound 13 (IC50=10nM), was 536-times more active than metronidazole, and 121-fold more effective than nitazoxanide against G. intestinalis. Compound 14 was 29-times more active than metronidazole and 6.5-fold more potent than nitazoxanide against T. vaginalis. Ureic derivatives 2, 3 and 5 showed moderate activity against L. amazonensis. None of them were active against T. cruzi. Ligand efficiency indexes analysis revealed higher intrinsic quality of the most active 2-acylamino derivatives than nitazoxanide and metronidazole. In silico toxicity profile was also computed for the most active compounds. A very low in vitro mammalian cytotoxicity was obtained for 13 and 14, showing selectivity indexes (SI) of 246,300 and 141,500, respectively. Nitazoxanide showed an excellent leishmanicidal and trypanocidal effect, repurposing this drug as potential new antikinetoplastid parasite compound. PMID:24529307

  16. Cryo-EM structure of the Plasmodium falciparum 80S ribosome bound to the anti-protozoan drug emetine

    PubMed Central

    Wong, Wilson; Bai, Xiao-chen; Brown, Alan; Fernandez, Israel S; Hanssen, Eric; Condron, Melanie; Tan, Yan Hong; Baum, Jake; Scheres, Sjors HW

    2014-01-01

    Malaria inflicts an enormous burden on global human health. The emergence of parasite resistance to front-line drugs has prompted a renewed focus on the repositioning of clinically approved drugs as potential anti-malarial therapies. Antibiotics that inhibit protein translation are promising candidates for repositioning. We have solved the cryo-EM structure of the cytoplasmic ribosome from the human malaria parasite, Plasmodium falciparum, in complex with emetine at 3.2 Å resolution. Emetine is an anti-protozoan drug used in the treatment of ameobiasis that also displays potent anti-malarial activity. Emetine interacts with the E-site of the ribosomal small subunit and shares a similar binding site with the antibiotic pactamycin, thereby delivering its therapeutic effect by blocking mRNA/tRNA translocation. As the first cryo-EM structure that visualizes an antibiotic bound to any ribosome at atomic resolution, this establishes cryo-EM as a powerful tool for screening and guiding the design of drugs that target parasite translation machinery. DOI: http://dx.doi.org/10.7554/eLife.03080.001 PMID:24913268

  17. Occurrence of Perkinsus olseni (Protozoa: Apicomplexa) and other parasites in the venerid commercial clam Pitar rostrata from Uruguay, southwestern Atlantic coast.

    PubMed

    Cremonte, Florencia; Balseiro, Pablo; Figueras, Antonio

    2005-04-01

    A study was conducted into the health status of natural populations of the venerid clam Pitar rostrata from Uruguay. Perkinsus sp. was detected in 22% of the clams. Severe hemocytic infiltration was detected in the tissues parasitized by this protozoan parasite. The sequencing of the ITS-5.8S gene cluster of the parasite confirmed that it belonged to the Perkinsus olseni species. Rickettsia or Chlamidia-like organisms were also found, with a prevalence of 11%, although without apparent host reaction; an unidentified species of Coccidia was found in the nephridia of 78% of the clams, with the intensity of infection ranging from moderate to high. A gregarine, Nematopsis-like organism was observed mainly in the epithelial cells of the intestine, without host response and with a prevalence of 56%. Of the metazoan parasites, trematodes were found in 11% of the individuals analyzed. PMID:15900692

  18. Present status of protozoan pathogens causing water-borne disease in northern part of El-Minia Governorate, Egypt.

    PubMed

    Khalifa, Refaat M A; Ahmad, Azza K; Abdel-Hafeez, Ekhlas H; Mosllem, Fadia A

    2014-12-01

    Little is known about the role of different water supplies in the diversity and public health significance of pathogenic protozoan parasites. Most of these organisms have been ubiquitous in waters worldwide. The numbers of waterborne infections indicate a significant risk for their transmission even by drinking water. Hence, a total of 336 water samples were collected during 2009-2013 from different water sources from different areas of northern part of El-Minia Govemnorate, Egypt and were investigated for pathogenic protozoa. They were examined by direct microscopy followed by Modified Ziehl- Neelsen and Giemsa stains. 140 samples (41.7 %) were positive (statistically significant; P value P<0.0003). Prevalence rates were in Summer (66.7%/), Spring (51.1%), Fall (26.2 %) and Winter (22.6%). These data were statistically significant (P<0.0001). The commonest protozoa detected as a single infection was Cryptosporidium sp. (53.17%) found in all water supplies, followed by Blastocystis hominis (15.87%), Cyclospora caytenensis (11.9%), Entamoeba hiseolytica/dispar (8.73%) Giardia lamblia (6.35%() and Naegleria sp., (3.97%). Moreover, there were 14 samples with mixed parsitic infection: they were Cryptosporidium sp. and B. hominis in six samples, Cryptosporidum sp. and C. caytenenisin five samples and Cryptosporidium sp. and E histolytica/dispar in three samples. The most common contamninated water source was ponds where 32 samples (66.7%) were-positive followed by canal water 30 samples (62.5%). The results were discussed and the recommendations were offered. PMID:25643498

  19. A genomewide overexpression screen identifies genes involved in the phosphatidylinositol 3-kinase pathway in the human protozoan parasite Entamoeba histolytica.

    PubMed

    Koushik, Amrita B; Welter, Brenda H; Rock, Michelle L; Temesvari, Lesly A

    2014-03-01

    Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and liver abscess. E. histolytica relies on motility, phagocytosis, host cell adhesion, and proteolysis of extracellular matrix for virulence. In eukaryotic cells, these processes are mediated in part by phosphatidylinositol 3-kinase (PI3K) signaling. Thus, PI3K may be critical for virulence. We utilized a functional genomics approach to identify genes whose products may operate in the PI3K pathway in E. histolytica. We treated a population of trophozoites that were overexpressing genes from a cDNA library with a near-lethal dose of the PI3K inhibitor wortmannin. This screen was based on the rationale that survivors would be overexpressing gene products that directly or indirectly function in the PI3K pathway. We sequenced the overexpressed genes in survivors and identified a cDNA encoding a Rap GTPase, a protein previously shown to participate in the PI3K pathway. This supports the validity of our approach. Genes encoding a coactosin-like protein, EhCoactosin, and a serine-rich E. histolytica protein (SREHP) were also identified. Cells overexpressing EhCoactosin or SREHP were also less sensitive to a second PI3K inhibitor, LY294002. This corroborates the link between these proteins and PI3K. Finally, a mutant cell line with an increased level of phosphatidylinositol (3,4,5)-triphosphate, the product of PI3K activity, exhibited increased expression of SREHP and EhCoactosin. This further supports the functional connection between these proteins and PI3K in E. histolytica. To our knowledge, this is the first forward-genetics screen adapted to reveal genes participating in a signal transduction pathway in this pathogen. PMID:24442890

  20. A genome-wide over-expression screen identifies genes involved in phagocytosis in the human protozoan parasite, Entamoeba histolytica.

    PubMed

    King, Ada V; Welter, Brenda H; Koushik, Amrita B; Gordon, Lindsay N; Temesvari, Lesly A

    2012-01-01

    Functional genomics and forward genetics seek to assign function to all known genes in a genome. Entamoeba histolytica is a protozoan parasite for which forward genetics approaches have not been extensively applied. It is the causative agent of amoebic dysentery and liver abscess, and infection is prevalent in developing countries that cannot prevent its fecal-oral spread. It is responsible for considerable global morbidity and mortality. Given that the E. histolytica genome has been sequenced, it should be possible to apply genomic approaches to discover gene function. We used a genome-wide over-expression screen to uncover genes regulating an important virulence function of E. histolytica, namely phagocytosis. We developed an episomal E. histolytica cDNA over-expression library, transfected the collection of plasmids into trophozoites, and applied a high-throughput screen to identify phagocytosis mutants in the population of over-expressing cells. The screen was based on the phagocytic uptake of human red blood cells loaded with the metabolic toxin, tubercidin. Expression plasmids were isolated from trophozoites that survived exposure to tubercidin-charged erythrocytes (phagocytosis mutants), and the cDNAs were sequenced. We isolated the gene encoding profilin, a well-characterized cytoskeleton-regulating protein with a known role in phagocytosis. This supports the validity of our approach. Furthermore, we assigned a phagocytic role to several genes not previously known to function in this manner. To our knowledge, this is the first genome-wide forward genetics screen to be applied to this pathogen. The study demonstrates the power of forward genetics in revealing genes regulating virulence in E. histolytica. In addition, the study validates an E. histolytica cDNA over-expression library as a valuable tool for functional genomics. PMID:22905196

  1. Quantitative assessment of the proliferation of the protozoan parasite Perkinsus marinus using a bioluminescence assay for ATP content

    PubMed Central

    Shridhar, Surekha; Hassan, Kolaleh; Sullivan, David J.; Vasta, Gerardo R.; Fernández Robledo, José A.

    2013-01-01

    Perkinsus marinus is a protozoan parasite that causes “Dermo” disease in the eastern oyster Crasssostrea virginica in coastal areas of the USA. Until now, intervention strategies against the parasite have found limited success, and Dermo still remains one of the main hurdles for the restoration of oyster populations. We adapted a commercial adenosine tri-phosphate (ATP) content-based assay to assess the in vitro proliferation of P. marinus in a 96-well plate format, and validated the method by measuring the effects of potential anti-proliferative compounds. The sensitivity (1.5–3.1 × 104 cells/well), linearity (R2 = 0.983), and signal stability (60 min) support the reliability of the assay for assessing cell proliferation. Validation of the assay by culturing P. marinus in the presence of increasing concentrations of triclosan showed a dose–response profile. The IC50 value obtained was higher than that reported earlier, possibly due to the use of different viability assay methods and a different P. marinus strain. The antibiotics G418 and tetracycline and the herbicide fluridone were active against P. marinus proliferation; the IC50 of chloramphenicol, ciprofloxacin, and atrazine was relatively high suggesting either off-target effects or inability to reach the targets. The validation of the ATP-based assay, together with significant advantages of the Perkinsus culture methodology (homogeneity, reproducibility, and high cell densities), underscores the value of this assay for developing high-throughput screens for the identification of novel leader compounds against Perkinsus species, and most importantly, for the closely-related apicomplexan parasites. PMID:24533297

  2. Molecular and phylogenetic characterization of honey bee viruses, Nosema microsporidia, protozoan parasites, and parasitic mites in China.

    PubMed

    Yang, Bu; Peng, Guangda; Li, Tianbang; Kadowaki, Tatsuhiko

    2013-02-01

    China has the largest number of managed honey bee colonies, which produce the highest quantity of honey and royal jelly in the world; however, the presence of honey bee pathogens and parasites has never been rigorously identified in Chinese apiaries. We thus conducted a molecular survey of honey bee RNA viruses, Nosema microsporidia, protozoan parasites, and tracheal mites associated with nonnative Apis mellifera ligustica and native Apis cerana cerana colonies in China. We found the presence of black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), and sacbrood virus (SBV), but not that of acute bee paralysis virus (ABPV) or Kashmir bee virus (KBV). DWV was the most prevalent in the tested samples. Phylogenies of Chinese viral isolates demonstrated that genetically heterogeneous populations of BQCV, CBPV, DWV, and A. cerana-infecting SBV, and relatively homogenous populations of IAPV and A. meliifera-infecting new strain of SBV with single origins, are spread in Chinese apiaries. Similar to previous observations in many countries, Nosema ceranae, but not Nosema apis, was prevalent in the tested samples. Crithidia mellificae, but not Apicystis bombi was found in five samples, including one A. c. cerana colony, demonstrating that C. mellificae is capable of infecting multiple honey bee species. Based on kinetoplast-encoded cytochrome b sequences, the C. mellificae isolate from A. c. cerana represents a novel haplotype with 19 nucleotide differences from the Chinese and Japanese isolates from A. m. ligustica. This suggests that A. c. cerana is the native host for this specific haplotype. The tracheal mite, Acarapis woodi, was detected in one A. m. ligustica colony. Our results demonstrate that honey bee RNA viruses, N. ceranae, C. mellificae, and tracheal mites are present in Chinese apiaries, and some might be originated from native Asian honey bees. PMID:23467539

  3. A Genomewide Overexpression Screen Identifies Genes Involved in the Phosphatidylinositol 3-Kinase Pathway in the Human Protozoan Parasite Entamoeba histolytica

    PubMed Central

    Koushik, Amrita B.; Welter, Brenda H.; Rock, Michelle L.

    2014-01-01

    Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and liver abscess. E. histolytica relies on motility, phagocytosis, host cell adhesion, and proteolysis of extracellular matrix for virulence. In eukaryotic cells, these processes are mediated in part by phosphatidylinositol 3-kinase (PI3K) signaling. Thus, PI3K may be critical for virulence. We utilized a functional genomics approach to identify genes whose products may operate in the PI3K pathway in E. histolytica. We treated a population of trophozoites that were overexpressing genes from a cDNA library with a near-lethal dose of the PI3K inhibitor wortmannin. This screen was based on the rationale that survivors would be overexpressing gene products that directly or indirectly function in the PI3K pathway. We sequenced the overexpressed genes in survivors and identified a cDNA encoding a Rap GTPase, a protein previously shown to participate in the PI3K pathway. This supports the validity of our approach. Genes encoding a coactosin-like protein, EhCoactosin, and a serine-rich E. histolytica protein (SREHP) were also identified. Cells overexpressing EhCoactosin or SREHP were also less sensitive to a second PI3K inhibitor, LY294002. This corroborates the link between these proteins and PI3K. Finally, a mutant cell line with an increased level of phosphatidylinositol (3,4,5)-triphosphate, the product of PI3K activity, exhibited increased expression of SREHP and EhCoactosin. This further supports the functional connection between these proteins and PI3K in E. histolytica. To our knowledge, this is the first forward-genetics screen adapted to reveal genes participating in a signal transduction pathway in this pathogen. PMID:24442890

  4. Morpho-functional characterization and esterase patterns of the midgut of Tribolium castaneum Herbst, 1797 (Coleoptera: Tenebrionidae) parasitized by Gregarina cuneata (Apicomplexa: Eugregarinidae).

    PubMed

    Gigliolli, Adriana A Sinópolis; Lapenta, Ana Silva; Ruvolo-Takasusuki, Maria Claudia Colla; Abrahão, Josielle; Conte, Hélio

    2015-09-01

    Tribolium castaneum (Coleoptera: Tenebrionidae) is a common pest of stored grains and byproducts and is normally infected by Gregarina cuneata (Apicomplexa: Eugregarinidae). The life cycle of this parasite includes the sporozoite, trophozoite, gamont, gametocyte, and oocyst stages, which occur between the epithelium and lumen of the host's midgut. This study aims to describe the morphofunctional alterations in the midgut and determine the esterase patterns in T. castaneum when parasitized by gregarines. To achieve this purpose, midguts of adult insects were isolated, processed, and analysed using light and electron microscopy. We determined total protein content, amylase activity, and the expression and related activities of the esterases by using polyacrylamide gel electrophoresis (PAGE). The midgut of T. castaneum is formed by digestive, regenerative, and endocrine cells. The effects of parasitism on the digestive cells are severe, because the gregarines remain attached to these cells to absorb all the nutrients they need throughout their development. In these cells, the most common alterations observed include expansion and fragmentation of the rough endoplasmic reticulum, development of the smooth endoplasmic reticulum, changes in mitochondrial cristae, cytoplasmic vacuolization, formation of myelin structures, spherites, large intercellular spaces, autophagic vesicles, expansion of the basal labyrinth, and cytoplasmic protrusions. Deposits of glycogen granules were also observed. Amylase activity was reduced in parasitized insects. Regenerative cells were found in disorganized crypts and did not differentiate into new cells, thus, compromising the restoration of the damaged epithelium. Though few morphological alterations were observed in the endocrine cells, results suggest that the synthesis and/or release of hormones might be impaired. Nine esterases (EST-1 to 9) were identified in the midgut of T. castaneum and were expressed in varying levels in response to parasitism. Two additional isoforms of esterases were exclusively identified in the parasitized insects. The results of this study suggest that gregarines alter the morphology and physiology of the midgut. The changes may result in nutritional depletion and the impairment of other physiological processes, such as reproduction and development of the host. Thus, further studies are needed to uncover the possibility of utilizing gregarines as biological controllers of the insect pest population. PMID:26072335

  5. A Novel Soluble Immune-Type Receptor (SITR) in Teleost Fish: Carp SITR Is Involved in the Nitric Oxide-Mediated Response to a Protozoan Parasite

    PubMed Central

    Ribeiro, Carla M. S.; Bird, Steve; Raes, Geert; Ghassabeh, Gholamreza H.; Schijns, Virgil E. J. C.; Pontes, Maria J. S. L.; Savelkoul, Huub F. J.; Wiegertjes, Geert F.

    2011-01-01

    Background The innate immune system relies upon a wide range of germ-line encoded receptors including a large number of immunoglobulin superfamily (IgSF) receptors. Different Ig-like immune receptor families have been reported in mammals, birds, amphibians and fish. Most innate immune receptors of the IgSF are type I transmembrane proteins containing one or more extracellular Ig-like domains and their regulation of effector functions is mediated intracellularly by distinct stimulatory or inhibitory pathways. Methodology/Principal Findings Carp SITR was found in a substracted cDNA repertoire from carp macrophages, enriched for genes up-regulated in response to the protozoan parasite Trypanoplasma borreli. Carp SITR is a type I protein with two extracellular Ig domains in a unique organisation of a N-proximal V/C2 (or I-) type and a C-proximal V-type Ig domain, devoid of a transmembrane domain or any intracytoplasmic signalling motif. The carp SITR C-proximal V-type Ig domain, in particular, has a close sequence similarity and conserved structural characteristics to the mammalian CD300 molecules. By generating an anti-SITR antibody we could show that SITR protein expression was restricted to cells of the myeloid lineage. Carp SITR is abundantly expressed in macrophages and is secreted upon in vitro stimulation with the protozoan parasite T. borreli. Secretion of SITR protein during in vivo T. borreli infection suggests a role for this IgSF receptor in the host response to this protozoan parasite. Overexpression of carp SITR in mouse macrophages and knock-down of SITR protein expression in carp macrophages, using morpholino antisense technology, provided evidence for the involvement of carp SITR in the parasite-induced NO production. Conclusion/Significance We report the structural and functional characterization of a novel soluble immune-type receptor (SITR) in a teleost fish and propose a role for carp SITR in the NO-mediated response to a protozoan parasite. PMID:21305002

  6. The potential of secondary metabolites from plants as drugs or leads against protozoan neglected diseases - part II.

    PubMed

    Schmidt, T J; Khalid, S A; Romanha, A J; Alves, T Ma; Biavatti, M W; Brun, R; Da Costa, F B; de Castro, S L; Ferreira, V F; de Lacerda, M V G; Lago, J H G; Leon, L L; Lopes, N P; das Neves Amorim, R C; Niehues, M; Ogungbe, I V; Pohlit, A M; Scotti, M T; Setzer, W N; de N C Soeiro, M; Steindel, M; Tempone, A G

    2012-01-01

    Infections with protozoan parasites are a major cause of disease and mortality in many tropical countries of the world. Diseases caused by species of the genera Trypanosoma (Human African Trypanosomiasis and Chagas Disease) and Leishmania (various forms of Leishmaniasis) are among the seventeen "Neglected Tropical Diseases" (NTDs) defined by the WHO. Furthermore, malaria (caused by various Plasmodium species) can be considered a neglected disease in certain countries and with regard to availability and affordability of the antimalarials. Living organisms, especially plants, provide an innumerable number of molecules with potential for the treatment of many serious diseases. The current review attempts to give an overview on the potential of such plant-derived natural products as antiprotozoal leads and/or drugs in the fight against NTDs. In part I, a general description of the diseases, the current state of therapy and need for new therapeuticals, assay methods and strategies applied in the search for new plant derived natural products against these diseases and an overview on natural products of terpenoid origin with antiprotozoal potential were given. The present part II compiles the current knowledge on natural products with antiprotozoal activity that are derived from the shikimate pathway (lignans, coumarins, caffeic acid derivatives), quinones of various structural classes, compounds formed via the polyketide pathways (flavonoids and related compounds, chromenes and related benzopyrans and benzofurans, xanthones, acetogenins from Annonaceae and polyacetylenes) as well as the diverse classes of alkaloids. In total, both parts compile the literature on almost 900 different plant-derived natural products and their activity data, taken from over 800 references. These data, as the result of enormous efforts of numerous research groups world-wide, illustrate that plant secondary metabolites represent an immensely rich source of chemical diversity with an extremely high potential to yield a wealth of lead structures towards new therapies for NTDs. Only a small percentage, however, of the roughly 200,000 plant species on earth have been studied chemically and only a small percentage of these plants or their constituents has been investigated for antiprotozoal activity. The repository of plant-derived natural products hence deserves to be investigated even more intensely than it has been up to present. PMID:22414104

  7. Characterization of XYN10B, a modular xylanase from the ruminal protozoan Polyplastron multivesiculatum, with a family 22 carbohydrate-binding module that binds to cellulose.

    PubMed Central

    Devillard, Estelle; Bera-Maillet, Christel; Flint, Harry J; Scott, Karen P; Newbold, C James; Wallace, R John; Jouany, Jean-Pierre; Forano, Evelyne

    2003-01-01

    A new xylanase gene, xyn10B, was isolated from the ruminal protozoan Polyplastron multivesiculatum and the gene product was characterized. XYN10B is the first protozoan family 10 glycoside hydrolase characterized so far and is a modular enzyme comprising a family 22 carbohydrate-binding module (CBM) preceding the catalytic domain. The CBM22 was shown to be a true CBM. It showed high affinity for soluble arabinoxylan and is the first example of a CBM22 that binds strongly to celluloses of various crystallinities. The enzymic properties of XYN10B were also analysed. Its optimal temperature and pH for activity were 39 degrees C and 7.0 respectively; these values being close to those of the ruminal ecosystem. The phylogenetic relationships between the XYN10B CBM22 or catalytic domain and related sequences from ruminal and non-ruminal bacteria and eukaryotes are reported. The xyn10B gene is shown to lack introns. PMID:12693992

  8. Application of a qPCR Assay with Melting Curve Analysis for Detection and Differentiation of Protozoan Oocysts in Human Fecal Samples from Dominican Republic

    PubMed Central

    Lalonde, Laura F.; Reyes, Julissa; Gajadhar, Alvin A.

    2013-01-01

    A quantitative polymerase chain reaction assay with melt curve analysis (qPCR-MCA) was applied for the detection of protozoan oocysts in 501 human fecal samples collected in Dominican Republic. Samples were subjected to qPCR using universal coccidia primers targeting 18S rDNA to detect oocysts followed by MCA to identify oocyst species based on amplicon melting temperature. Putative positive samples were also tested by conventional PCR and microscopy. Cystoisospora belli (×3), Cryptosporidium parvum (×3), Cryptosporidium hominis (×5), Cryptosporidium meleagridis (×1), Cryptosporidium canis (×1), and Cyclospora cayetanensis (×9) were detected by qPCR-MCA and confirmed by sequencing. This assay consistently detected 10 copies of the cloned target fragment and can be considered more efficient and sensitive than microscopy flotation methods for detecting multiple species of oocysts in human feces. The qPCR-MCA is a reliable protozoan oocyst screening assay for use on clinical and environmental samples in public health, food safety and veterinary programs. PMID:24019437

  9. Application of a qPCR assay with melting curve analysis for detection and differentiation of protozoan oocysts in human fecal samples from Dominican Republic.

    PubMed

    Lalonde, Laura F; Reyes, Julissa; Gajadhar, Alvin A

    2013-11-01

    A quantitative polymerase chain reaction assay with melt curve analysis (qPCR-MCA) was applied for the detection of protozoan oocysts in 501 human fecal samples collected in Dominican Republic. Samples were subjected to qPCR using universal coccidia primers targeting 18S rDNA to detect oocysts followed by MCA to identify oocyst species based on amplicon melting temperature. Putative positive samples were also tested by conventional PCR and microscopy. Cystoisospora belli (×3), Cryptosporidium parvum (×3), Cryptosporidium hominis (×5), Cryptosporidium meleagridis (×1), Cryptosporidium canis (×1), and Cyclospora cayetanensis (×9) were detected by qPCR-MCA and confirmed by sequencing. This assay consistently detected 10 copies of the cloned target fragment and can be considered more efficient and sensitive than microscopy flotation methods for detecting multiple species of oocysts in human feces. The qPCR-MCA is a reliable protozoan oocyst screening assay for use on clinical and environmental samples in public health, food safety and veterinary programs. PMID:24019437

  10. Inactivation credit of UV radiation for viruses, bacteria and protozoan (oo)cysts in water: a review.

    PubMed

    Hijnen, W A M; Beerendonk, E F; Medema, G J

    2006-01-01

    UV disinfection technology is of growing interest in the water industry since it was demonstrated that UV radiation is very effective against (oo)cysts of Cryptosporidium and Giardia, two pathogenic micro-organisms of major importance for the safety of drinking water. Quantitative Microbial Risk Assessment, the new concept for microbial safety of drinking water and wastewater, requires quantitative data of the inactivation or removal of pathogenic micro-organisms by water treatment processes. The objective of this study was to review the literature on UV disinfection and extract quantitative information about the relation between the inactivation of micro-organisms and the applied UV fluence. The quality of the available studies was evaluated and only high-quality studies were incorporated in the analysis of the inactivation kinetics. The results show that UV is effective against all waterborne pathogens. The inactivation of micro-organisms by UV could be described with first-order kinetics using fluence-inactivation data from laboratory studies in collimated beam tests. No inactivation at low fluences (offset) and/or no further increase of inactivation at higher fluences (tailing) was observed for some micro-organisms. Where observed, these were included in the description of the inactivation kinetics, even though the cause of tailing is still a matter of debate. The parameters that were used to describe inactivation are the inactivation rate constant k (cm(2)/mJ), the maximum inactivation demonstrated and (only for bacterial spores and Acanthamoeba) the offset value. These parameters were the basis for the calculation of the microbial inactivation credit (MIC="log-credits") that can be assigned to a certain UV fluence. The most UV-resistant organisms are viruses, specifically Adenoviruses, and bacterial spores. The protozoon Acanthamoeba is also highly UV resistant. Bacteria and (oo)cysts of Cryptosporidium and Giardia are more susceptible with a fluence requirement of <20 mJ/cm(2) for an MIC of 3 log. Several studies have reported an increased UV resistance of environmental bacteria and bacterial spores, compared to lab-grown strains. This means that higher UV fluences are required to obtain the same level of inactivation. Hence, for bacteria and spores, a correction factor of 2 and 4 was included in the MIC calculation, respectively, whereas some wastewater studies suggest that a correction of a factor of 7 is needed under these conditions. For phages and viruses this phenomenon appears to be of little significance and for protozoan (oo)cysts this aspect needs further investigation. Correction of the required fluence for DNA repair is considered unnecessary under the conditions of drinking water practice (no photo-repair, dark repair insignificant, esp. at higher (60 mJ/cm(2)) fluences) and probably also wastewater practice (photo-repair limited by light absorption). To enable accurate assessment of the effective fluence in continuous flow UV systems in water treatment practice, biodosimetry is still essential, although the use of computational fluid dynamics (CFD) improves the description of reactor hydraulics and fluence distribution. For UV systems that are primarily dedicated to inactivate the more sensitive pathogens (Cryptosporidium, Giardia, pathogenic bacteria), additional model organisms are needed to serve as biodosimeter. PMID:16386286

  11. Lipid kinases are essential for apicoplast homeostasis in Toxoplasma gondii.

    PubMed

    Daher, Wassim; Morlon-Guyot, Juliette; Sheiner, Lilach; Lentini, Gaëlle; Berry, Laurence; Tawk, Lina; Dubremetz, Jean-François; Wengelnik, Kai; Striepen, Boris; Lebrun, Maryse

    2015-04-01

    Phosphoinositides regulate numerous cellular processes by recruiting cytosolic effector proteins and acting as membrane signalling entities. The cellular metabolism and localization of phosphoinositides are tightly regulated by distinct lipid kinases and phosphatases. Here, we identify and characterize a unique phosphatidylinositol 3 kinase (PI3K) in Toxoplasma gondii, a protozoan parasite belonging to the phylum Apicomplexa. Conditional depletion of this enzyme and subsequently of its product, PI(3)P, drastically alters the morphology and inheritance of the apicoplast, an endosymbiotic organelle of algal origin that is a unique feature of many Apicomplexa. We searched the T.?gondii genome for PI(3)P-binding proteins and identified in total six PX and FYVE domain-containing proteins including a PIKfyve lipid kinase, which phosphorylates PI(3)P into PI(3,5)P2 . Although depletion of putative PI(3)P-binding proteins shows that they are not essential for parasite growth and apicoplast biology, conditional disruption of PIKfyve induces enlarged apicoplasts, as observed upon loss of PI(3)P. A similar defect of apicoplast homeostasis was also observed by knocking down the PIKfyve regulatory protein ArPIKfyve, suggesting that in T.?gondii, PI(3)P-related function for the apicoplast might mainly be to serve as a precursor for the synthesis of PI(3,5)P2 . Accordingly, PI3K is conserved in all apicomplexan parasites whereas PIKfyve and ArPIKfyve are absent in Cryptosporidium species that lack an apicoplast, supporting a direct role of PI(3,5)P2 in apicoplast homeostasis. This study enriches the already diverse functions attributed to PI(3,5)P2 in eukaryotic cells and highlights these parasite lipid kinases as potential drug targets. PMID:25329540

  12. Lipid kinases are essential for apicoplast homeostasis in Toxoplasma gondii

    PubMed Central

    Daher, Wassim; Morlon-Guyot, Juliette; Sheiner, Lilach; Lentini, Gaëlle; Berry, Laurence; Tawk, Lina; Dubremetz, Jean-François; Wengelnik, Kai; Striepen, Boris; Lebrun, Maryse

    2014-01-01

    Phosphoinositides regulate numerous cellular processes, by recruiting cytosolic effector proteins and acting as membrane signaling entities. The cellular metabolism and localization of phosphoinositides are tightly regulated by distinct lipid kinases and phosphatases. Here, we identify and characterize a unique phosphatidylinositol 3-Kinase (PI3K) in Toxoplasma gondii, a protozoan parasite belonging to the phylum Apicomplexa. Conditional depletion of this enzyme and subsequently of its product, PI(3)P, drastically alters the morphology and inheritance of the apicoplast, an endosymbiontic organelle of algal origin that is a unique feature of many Apicomplexa. We searched the T. gondii genome for PI(3)P binding proteins and identified in total six PX and FYVE-domain containing proteins including a PIKfyve lipid kinase, which phosphorylates PI(3)P into PI(3,5)P2. While depletion of putative PI(3)P binding proteins shows that they are not essential for parasite growth and apicoplast biology, conditional disruption of PIKfyve induces enlarged apicoplasts, as observed upon the loss of PI(3)P. A similar defect of apicoplast homeostasis was also observed by knocking-down the PIKfyve regulatory protein ArPIKfyve, suggesting that in T. gondii, PI(3)P-related function for the apicoplast might mainly be to serve as a precursor for the synthesis of PI(3,5)P2. Accordingly, PI3K is conserved in all apicomplexan parasites whereas PIKfyve and ArPIKfyve are absent in Cryptosporidium species which lack an apicoplast, supporting a direct role of PI(3,5)P2 in apicoplast homeostasis. This study enriches the already diverse functions attributed to PI(3,5)P2 in eukaryotic cells and highlights these parasite lipid kinases as potential drug targets. PMID:25329540

  13. DNA from Protozoan Parasites Babesia bovis, Trypanosoma cruzi, and T. brucei Is Mitogenic for B Lymphocytes and Stimulates Macrophage Expression of Interleukin12, Tumor Necrosis Factor Alpha, and Nitric Oxide

    Microsoft Academic Search

    LISL K. M. SHODA; KIMBERLY A. KEGERREIS; CARLOS E. SUAREZ; ISABEL RODITI; RICARDO S. CORRAL; GUSTAVO M. BERTOT; JUNZO NORIMINE; WENDY C. BROWN

    2001-01-01

    The activation of innate immune responses by genomic DNA from bacteria and several nonvertebrate organisms represents a novel mechanism of pathogen recognition. We recently demonstrated the CpG- dependent mitogenic activity of DNA from the protozoan parasite Babesia bovis for bovine B lymphocytes (W. C. Brown, D. M. Estes, S. E. Chantler, K. A. Kegerreis, and C. E. Suarez, Infect. Immun.

  14. Extrachromosomal DNA in the Apicomplexa.

    PubMed Central

    Wilson, R J; Williamson, D H

    1997-01-01

    Malaria and related apicomplexan parasites have two highly conserved organellar genomes: one is of plastid (pl) origin, and the other is mitochondrial (mt). The organization of both organellar DNA molecules from the human malaria parasite Plasmodium falciparum has been determined, and they have been shown to be tightly packed with genes. The 35-kb circular DNA is the smallest known vestigial plastid genome and is presumed to be functional. All but two of its recognized genes are involved with genetic expression: one of the two encodes a member of the clp family of molecular chaperones, and the other encodes a conserved protein of unknown function found both in algal plastids and in eubacterial genomes. The possible evolutionary source and intracellular location of the plDNA are discussed. The 6-kb tandemly repeated mt genome is the smallest known and codes for only three proteins (cytochrome b and two subunits of cytochrome oxidase) as well as two bizarrely fragmented rRNAs. The organization of the mt genome differs somewhat among genera. The mtDNA sequence provides information not otherwise available about the structure of apicomplexan cytochrome b as well as the unusually fragmented rRNAs. The malarial mtDNA has a phage-like replication mechanism and undergoes extensive recombination like the mtDNA of some other lower eukaryotes. PMID:9106361

  15. Tomaculocystis corpulenta n. gen., n. sp. (Apicomplexa: Eugregarinorida) parasitizing the little yellow cockroach, Cariblatta lutea (Blattodea: Ectobiidae), in Alabama and Florida with recognition of Tomaculocystis cylindrosa n. comb. and Tomaculocystis mukundai n. comb. parasitizing ectobiid cockroaches in India.

    PubMed

    Clopton, Richard E

    2015-02-01

    Tomaculocystis corpulenta n. gen., n. sp. (Apicomplexa: Eugregarinorida: Septatorina: Gregarinidae) is described from populations of the little yellow cockroach, Cariblatta lutea (Blattodea: Ectobiidae), established in laboratory culture from samples collected in Alabama and Florida. Tomaculocystis n. gen. are differentiated from other members of Gregarina by a markedly elliptoid gametocyst inside a persistent, lomentiform hyaline epicyst; developmental organization and growth of the spore tubes from gametocyst surface tumidi; and dehiscence by extrusion of non-chain forming oocysts through spore tubes that barely extend beyond the epicyst wall. Gregarina cylindrosa, Gregarina discocephala, and Gregarina mukundai are recognized as members of Tomaculocystis, and G. cylindrosa is recognized as the senior synonym of G. discocephala. Thus, Tomaculocystis cylindrosa n. comb. and Tomaculocystis mukundai n. comb. are formed. Species of Tomaculocystis are distinguished based on gamont deutomerite and oocyst shape and size. The oocysts of T. corpulenta are broadly dolioform, lack 4 polar knobs, and possess distinct, unique polar plates. Oocysts of all other known species in the genus are more oblong in shape, possess 4 polar knobs, and lack the distinct polar plates observed in the oocysts of T. corpulenta. Host utilization and geographic distribution among gregarine genera parasitizing the cockroach family Ectobiidae reveal a pattern of host-parasite specificity linking gregarine genera with ectobiidid subfamilies. Overall patterns suggest a hypothesis of European endemicy for Gamocystis, but hypotheses for the origin and radiation of Tomaculocystis or species of Gregarina infecting cockroaches are confounded by the cosmopolitan spread of pest cockroach species among humans. PMID:25153145

  16. Sequencing and analysis of chromosome 1 of Eimeria tenella reveals a unique segmental organization

    PubMed Central

    Ling, King-Hwa; Rajandream, Marie-Adele; Rivailler, Pierre; Ivens, Alasdair; Yap, Soon-Joo; Madeira, Alda M.B.N.; Mungall, Karen; Billington, Karen; Yee, Wai-Yan; Bankier, Alan T.; Carroll, Fionnadh; Durham, Alan M.; Peters, Nicholas; Loo, Shu-San; Mat Isa, Mohd Noor; Novaes, Jeniffer; Quail, Michael; Rosli, Rozita; Nor Shamsudin, Mariana; Sobreira, Tiago J.P.; Tivey, Adrian R.; Wai, Siew-Fun; White, Sarah; Wu, Xikun; Kerhornou, Arnaud; Blake, Damer; Mohamed, Rahmah; Shirley, Martin; Gruber, Arthur; Berriman, Matthew; Tomley, Fiona; Dear, Paul H.; Wan, Kiew-Lian

    2007-01-01

    Eimeria tenella is an intracellular protozoan parasite that infects the intestinal tracts of domestic fowl and causes coccidiosis, a serious and sometimes lethal enteritis. Eimeria falls in the same phylum (Apicomplexa) as several human and animal parasites such as Cryptosporidium, Toxoplasma, and the malaria parasite, Plasmodium. Here we report the sequencing and analysis of the first chromosome of E. tenella, a chromosome believed to carry loci associated with drug resistance and known to differ between virulent and attenuated strains of the parasite. The chromosome—which appears to be representative of the genome—is gene-dense and rich in simple-sequence repeats, many of which appear to give rise to repetitive amino acid tracts in the predicted proteins. Most striking is the segmentation of the chromosome into repeat-rich regions peppered with transposon-like elements and telomere-like repeats, alternating with repeat-free regions. Predicted genes differ in character between the two types of segment, and the repeat-rich regions appear to be associated with strain-to-strain variation. PMID:17284678

  17. Sequence Variation in Superoxide Dismutase Gene of Toxoplasma gondii among Various Isolates from Different Hosts and Geographical Regions

    PubMed Central

    Wang, Shuai; Cao, Aiping; Li, Xun; Zhao, Qunli; Liu, Yuan; Cong, Hua; He, Shenyi; Zhou, Huaiyu

    2015-01-01

    Toxoplasma gondii, an obligate intracellular protozoan parasite of the phylum Apicomplexa, can infect all warm-blooded vertebrates, including humans, livestock, and marine mammals. The aim of this study was to investigate whether superoxide dismutase (SOD) of T. gondii can be used as a new marker for genetic study or a potential vaccine candidate. The partial genome region of the SOD gene was amplified and sequenced from 10 different T. gondii isolates from different parts of the world, and all the sequences were examined by PCR-RFLP, sequence analysis, and phylogenetic reconstruction. The results showed that partial SOD gene sequences ranged from 1,702 bp to 1,712 bp and A + T contents varied from 50.1% to 51.1% among all examined isolates. Sequence alignment analysis identified total 43 variable nucleotide positions, and these results showed that 97.5% sequence similarity of SOD gene among all examined isolates. Phylogenetic analysis revealed that these SOD sequences were not an effective molecular marker for differential identification of T. gondii strains. The research demonstrated existence of low sequence variation in the SOD gene among T. gondii strains of different genotypes from different hosts and geographical regions. PMID:26174817

  18. Structural Evidence for Actin-like Filaments in Toxoplasma gondii Using High-Resolution Low-Voltage Field Emission Scanning Electron Microscopy

    NASA Astrophysics Data System (ADS)

    Schatten, Heide; Sibley, L. David; Ris, Hans

    2003-08-01

    The protozoan parasite Toxoplasma gondii is representative of a large group of parasites within the phylum Apicomplexa, which share a highly unusual motility system that is crucial for locomotion and active host cell invasion. Despite the importance of motility in the pathology of these unicellular organisms, the motor mechanisms for locomotion remain uncertain, largely because only limited data exist about composition and organization of the cytoskeleton. By using cytoskeleton stabilizing protocols on membrane-extracted parasites and novel imaging with high-resolution low-voltage field emission scanning electron microscopy (LVFESEM), we were able to visualize for the first time a network of actin-sized filaments just below the cell membrane. A complex cytoskeletal network remained after removing the actin-sized fibers with cytochalasin D, revealing longitudinally arranged, subpellicular microtubules and intermediate-sized fibers of 10 nm, which, in stereo images, are seen both above and below the microtubules. These approaches open new possibilities to characterize more fully the largely unexplored and unconventional cytoskeletal motility complex in apicomplexan parasites.

  19. TREP, a novel protein necessary for gliding motility of the malaria sporozoite.

    PubMed

    Combe, Audrey; Moreira, Cristina; Ackerman, Susan; Thiberge, Sabine; Templeton, Thomas J; Ménard, Robert

    2009-03-01

    The invasive stages of parasites of the protozoan phylum Apicomplexa have the capacity to traverse host tissues and invade host cells using a unique type of locomotion called gliding motility. Gliding motility is powered by a sub-membranous actin-myosin motor, and the force generated by the motor is transduced to the parasite surface by transmembrane proteins of the apicomplexan-specific thrombospondin-related anonymous protein (TRAP) family. These proteins possess short cytoplasmic tails that interact with the actin-myosin motor via the glycolytic enzyme aldolase. Gliding motility of the Plasmodium sporozoite, the stage of the malaria parasite that is transmitted by the mosquito to the mammalian host, depends on the TRAP protein. We describe a second protein, herein termed TREP, which also plays a role in the gliding motility of the Plasmodium sporozoite. TREP is a transmembrane protein that possesses a short cytoplasmic tail typical of members of the TRAP family of proteins, as well as a large extracellular region that contains a single thrombospondin type 1 repeat domain. TREP transcripts are expressed predominantly in oocyst stage sporozoites. Plasmodium berghei sporozoites harbouring a disrupted TREP gene have a highly diminished capacity to invade mosquito salivary glands and display a severe defect in gliding motility. We conclude that the gliding motility of the Plasmodium sporozoite in the mosquito depends on at least two proteins, TRAP and TREP. PMID:19000911

  20. Unique apicomplexan IMC sub-compartment proteins are early markers for apical polarity in the malaria parasite

    PubMed Central

    Poulin, Benoit; Patzewitz, Eva-Maria; Brady, Declan; Silvie, Olivier; Wright, Megan H.; Ferguson, David J. P.; Wall, Richard J.; Whipple, Sarah; Guttery, David S.; Tate, Edward W.; Wickstead, Bill; Holder, Anthony A.; Tewari, Rita

    2013-01-01

    Summary The phylum Apicomplexa comprises over 5000 intracellular protozoan parasites, including Plasmodium and Toxoplasma, that are clinically important pathogens affecting humans and livestock. Malaria parasites belonging to the genus Plasmodium possess a pellicle comprised of a plasmalemma and inner membrane complex (IMC), which is implicated in parasite motility and invasion. Using live cell imaging and reverse genetics in the rodent malaria model P. berghei, we localise two unique IMC sub-compartment proteins (ISPs) and examine their role in defining apical polarity during zygote (ookinete) development. We show that these proteins localise to the anterior apical end of the parasite where IMC organisation is initiated, and are expressed at all developmental stages, especially those that are invasive. Both ISP proteins are N-myristoylated, phosphorylated and membrane-bound. Gene disruption studies suggest that ISP1 is likely essential for parasite development, whereas ISP3 is not. However, an absence of ISP3 alters the apical localisation of ISP1 in all invasive stages including ookinetes and sporozoites, suggesting a coordinated function for these proteins in the organisation of apical polarity in the parasite. PMID:24244852

  1. Isolation of Besnoitia besnoiti from infected cattle in Portugal.

    PubMed

    Cortes, H C E; Reis, Y; Waap, H; Vidal, R; Soares, H; Marques, I; Pereira da Fonseca, I; Fazendeiro, I; Ferreira, M L; Caeiro, V; Shkap, V; Hemphill, A; Leitão, A

    2006-11-01

    Besnoitia besnoiti, an obligate intracellular protozoan parasite belonging to the phylum apicomplexa, is the causative agent of bovine besnoitiosis. Besnoitiosis is responsible for significant losses in the cattle industry of Africa and Mediterranean countries due to the high morbidity rate, abortion and infertility in males. The acute stage of disease is associated with the proliferative forms (tachyzoites) and is characterized by fever, whimpery, general weakness and swelling of the superficial lymph nodes. During the following chronic stage, a huge number of cysts are formed mainly in the subcutaneous tissues. This process is non-reversible, and chronic besnoitiosis is characterized by hyper-sclerodermia, hyperkeratosis, alopecia and, in bulls, atrophy, sclerosis and focal necrosis that cause irreversible lesions in the testis. In this paper we report on the identification of large cysts in the skin of a cow and a bull in Portugal, which presented loss of hair and enlargement and pachydermis all over the body. The observation of a two-layered cyst wall within the host cell, the encapsulation of the host cell by a large outer cyst wall, and the subcutaneous localization of the cysts within the host, were characteristic for B. besnoiti. The parasites were isolated from the infected animals and successfully propagated in Vero cells without prior passages in laboratory animals. Morphological characterization of B. besnoiti tachyzoites and the amplification of the 149 bp segment from the internal transcribed spacer 1 (ITS1), aided with specific primers, confirmed the identification of B. besnoiti. PMID:16822614

  2. Population Abundance of Potentially Pathogenic Organisms in Intestinal Microbiome of Jungle Crow (Corvus macrorhynchos) Shown with 16S rRNA Gene-Based Microbial Community Analysis

    PubMed Central

    Maeda, Isamu; Siddiki, Mohammad Shohel Rana; Nozawa-Takeda, Tsutomu; Tsukahara, Naoki; Tani, Yuri; Naito, Taki; Sugita, Shoei

    2013-01-01

    Jungle Crows (Corvus macrorhynchos) prefer human habitats because of their versatility in feeding accompanied with human food consumption. Therefore, it is important from a public health viewpoint to characterize their intestinal microbiota. However, no studies have been involved in molecular characterization of the microbiota based on huge and reliable number of data acquisition. In this study, 16S rRNA gene-based microbial community analysis coupled with the next-generation DNA sequencing techniques was applied to the taxonomic classification of intestinal microbiome for three jungle crows. Clustering of the reads into 130 operational taxonomic units showed that at least 70% of analyzed sequences for each crow were highly homologous to Eimeria sp., which belongs to the protozoan phylum Apicomplexa. The microbiotas of three crows also contained potentially pathogenic bacteria with significant percentages, such as the genera Campylobacter and Brachyspira. Thus, the profiling of a large number of 16S rRNA gene sequences in crow intestinal microbiomes revealed the high-frequency existence or vestige of potentially pathogenic microorganisms. PMID:24058905

  3. Pelagicoccus mobilis gen. nov., sp. nov., Pelagicoccus albus sp. nov. and Pelagicoccus litoralis sp. nov., three novel members of subdivision 4 within the phylum 'Verrucomicrobia', isolated from seawater by in situ cultivation.

    PubMed

    Yoon, Jaewoo; Yasumoto-Hirose, Mina; Matsuo, Yoshihide; Nozawa, Midori; Matsuda, Satoru; Kasai, Hiroaki; Yokota, Akira

    2007-07-01

    Five Gram-negative, white-pigmented, spherical, chemoheterotrophic bacteria were isolated from seawater from Japan and the Republic of Palau by use of an in situ cultivation technique. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the five novel isolates, 02PA-Ca-133(T), YM14-201(T), H-MN57(T), H-MN48 and MN1-156, were closely affiliated to members of subdivision 4 within the phylum 'Verrucomicrobia'. The novel isolates shared 96-100 % sequence similarity with each other and showed less than 90 % similarity with the cultivated strains of subdivision 4. DNA-DNA relatedness values between strains 02PA-Ca-133(T), YM14-201(T) and H-MN57(T) were less than 70 %; the value commonly accepted as the threshold for the phylogenetic definition of a species. Antibiotic susceptibility tests and amino acid analysis of cell-wall hydrolysates indicated that the novel isolates did not contain muramic acid or diaminopimelic acid in their cell walls, suggesting that these strains lack peptidoglycan. The DNA G+C contents of the five strains were 51-57 mol%. The major menaquinone was MK-7 and C(16 : 0), C(16 : 1)omega 7c and anteiso-C(15 : 0) were the major fatty acids. On the basis of polyphasic taxonomic evidence, it is concluded that these strains should be classified as representing a new genus and three novel species in subdivision 4 of the phylum 'Verrucomicrobia', for which the names Pelagicoccus mobilis gen. nov., sp. nov. [type strain 02PA-Ca-133(T) (=MBIC08004(T)=IAM 15422(T)=KCTC 13126(T))], Pelagicoccus albus sp. nov. [type strain YM14-201(T) (=MBIC08272(T)=IAM 15421(T)=KCTC 13124(T))] and Pelagicoccus litoralis sp. nov. [type strain H-MN57(T) (=MBIC08273(T)=IAM 15423(T)=KCTC 13125(T))] are proposed. PMID:17625161

  4. Correlation between CD4 counts of HIV patients and enteric protozoan in different seasons – An experience of a tertiary care hospital in Varanasi (India)

    PubMed Central

    Tuli, Lekha; Gulati, Anil K; Sundar, Shyam; Mohapatra, Tribhuban M

    2008-01-01

    Background Protozoan infections are the most serious among all the superimposed infections in HIV patients and claim a number of lives every year. The line of treatment being different for diverse parasites necessitates a definitive diagnosis of the etiological agents to avoid empirical treatment. Thus, the present study has been aimed to elucidate the associations between diarrhoea and CD4 counts and to study the effect of HAART along with management of diarrhoea in HIV positive patients. This study is the first of its kind in this area where an attempt was made to correlate seasonal variation and intestinal protozoan infestations. Methods The study period was from January 2006 to October 2007 wherein stool samples were collected from 366 HIV positive patients with diarrhea attending the ART centre, inpatient department and ICTC of S.S. hospital, I.M.S., B.H.U., Varanasi. Simultaneously, CD4 counts were recorded to assess the status of HIV infection vis-à-vis parasitic infection. The identification of pathogens was done on the basis of direct microscopy and different staining techniques. Results Of the 366 patients, 112 had acute and 254 had chronic diarrhea. The percentages of intestinal protozoa detected were 78.5% in acute and 50.7% in chronic cases respectively. Immune restoration was observed in 36.6% patients after treatment on the basis of clinical observation and CD4 counts. In 39.8% of HIV positive cases Cryptosporidium spp. was detected followed by Microsporidia spp. (26.7%). The highest incidence of intestinal infection was in the rainy season. However, infection with Cyclospora spp. was at its peak in the summer. Patients with chronic diarrhea had lower CD4 cell counts. The maximum parasitic isolation was in the patients whose CD4 cell counts were below 200 cells/?l. Conclusion There was an inverse relation between the CD4 counts and duration of diarrhea. Cryptosporidium spp. was isolated maximum among all the parasites in the HIV patients. The highest incidence of infection was seen in the rainy season. PMID:18713475

  5. Acanthopleuribacter pedis gen. nov., sp. nov., a marine bacterium isolated from a chiton, and description of Acanthopleuribacteraceae fam. nov., Acanthopleuribacterales ord. nov., Holophagaceae fam. nov., Holophagales ord. nov. and Holophagae classis nov. in the phylum 'Acidobacteria'.

    PubMed

    Fukunaga, Yukiyo; Kurahashi, Midori; Yanagi, Kensuke; Yokota, Akira; Harayama, Shigeaki

    2008-11-01

    Strain FYK2218(T) was isolated from a specimen of the chiton Acanthopleura japonica, which had been collected from a beach on the Boso peninsula in Japan. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the strain belonged to the phylum 'Acidobacteria'. The most closely related type strains to strain FYK2218(T) were Holophaga foetida TMBS4(T) (83.6 % 16S rRNA gene sequence similarity) and Geothrix fermentans H-5(T) (83.6 %) in subdivision 8 of the 'Acidobacteria'. Cells of FYK2218(T) were motile, rod-shaped, Gram-negative, mesophilic and strictly aerobic. The G+C content of the strain was 56.7 mol%. The strain had isoprenoid quinones MK-6 and MK-7 as major components. Major fatty acids of the strain were iso-C(15 : 0), iso-C(17 : 0), C(16 : 0) and C(20 : 5)omega3c (cis-5,8,11,14,17-eicosapentaenoic acid). From the taxonomic data obtained in this study, it is proposed that the new marine isolate be placed into a novel genus and species named Acanthopleuribacter pedis gen. nov., sp. nov. within the new family, order and class Acanthopleuribacteraceae fam. nov., Acanthopleuribacterales ord. nov. and Holophagae classis nov. The family Holophagaceae fam. nov. is also described. The type strain of Acanthopleuribacter pedis is FYK2218(T) (=NBRC 101209(T) =KCTC 12899(T)). PMID:18984699

  6. Phylum Level Change in the Cecal and Fecal Gut Communities of Rats Fed Diets Containing Different Fermentable Substrates Supports a Role for Nitrogen as a Factor Contributing to Community Structure

    PubMed Central

    Kalmokoff, Martin; Franklin, Jeff; Petronella, Nicholas; Green, Judy; Brooks, Stephen P.J.

    2015-01-01

    Fermentation differs between the proximal and distal gut but little is known regarding how the bacterial communities differ or how they are influenced by diet. In order to investigate this, we compared community diversity in the cecum and feces of rats by 16S rRNA gene content and DNA shot gun metagenomics after feeding purified diets containing different fermentable substrates. Gut community composition was dependent on the source of fermentable substrate included in the diet. Cecal communities were dominated by Firmicutes, and contained a higher abundance of Lachnospiraceae compared to feces. In feces, community structure was shifted by varying degrees depending on diet towards the Bacteroidetes, although this change was not always evident from 16S rRNA gene data. Multi-dimensional scaling analysis (PCoA) comparing cecal and fecal metagenomes grouped by location within the gut rather than by diet, suggesting that factors in addition to substrate were important for community change in the distal gut. Differentially abundant genes in each environment supported this shift away from the Firmicutes in the cecum (e.g., motility) towards the Bacteroidetes in feces (e.g., Bacteroidales transposons). We suggest that this phylum level change reflects a shift to ammonia as the primary source of nitrogen used to support continued microbial growth in the distal gut. PMID:25954902

  7. Phylum level change in the cecal and fecal gut communities of rats fed diets containing different fermentable substrates supports a role for nitrogen as a factor contributing to community structure.

    PubMed

    Kalmokoff, Martin; Franklin, Jeff; Petronella, Nicholas; Green, Judy; Brooks, Stephen P J

    2015-01-01

    Fermentation differs between the proximal and distal gut but little is known regarding how the bacterial communities differ or how they are influenced by diet. In order to investigate this, we compared community diversity in the cecum and feces of rats by 16S rRNA gene content and DNA shot gun metagenomics after feeding purified diets containing different fermentable substrates. Gut community composition was dependent on the source of fermentable substrate included in the diet. Cecal communities were dominated by Firmicutes, and contained a higher abundance of Lachnospiraceae compared to feces. In feces, community structure was shifted by varying degrees depending on diet towards the Bacteroidetes, although this change was not always evident from 16S rRNA gene data. Multi-dimensional scaling analysis (PCoA) comparing cecal and fecal metagenomes grouped by location within the gut rather than by diet, suggesting that factors in addition to substrate were important for community change in the distal gut. Differentially abundant genes in each environment supported this shift away from the Firmicutes in the cecum (e.g., motility) towards the Bacteroidetes in feces (e.g., Bacteroidales transposons). We suggest that this phylum level change reflects a shift to ammonia as the primary source of nitrogen used to support continued microbial growth in the distal gut. PMID:25954902

  8. Recognizing the importance of exposure-dose-response dynamics for ecotoxicity assessment: nitrofurazone-induced antioxidase activity and mRNA expression in model protozoan Euplotes vannus.

    PubMed

    Hong, Yazhen; Liu, Shuxing; Lin, Xiaofeng; Li, Jiqiu; Yi, Zhenzhen; Al-Rasheid, Khaled A S

    2015-06-01

    The equivocality of dose-response relationships has, in practice, hampered the application of biomarkers as a means to evaluate environmental risk, yet this important issue has not yet been fully recognized or explored. This paper evaluates the potential of antioxidant enzymes in the ciliated protozoan Euplotes vannus for use as biomarkers. Dose-response dynamics, together with both the enzyme activity and the gene expression of the antioxidant enzymes, superoxide dismutase, and glutathione peroxidase, were investigated when E. vannus were exposed to graded doses of nitrofurazone for several discrete durations. Mathematical models were explored to characterize the dose-response profiles and, specifically, to identify any equivocality in terms of endpoint. Significant differences were found in both enzyme activity and messenger RNA (mRNA) expression in the E. vannus treated with nitrofurazone, and the interactions between exposure dosage and duration were significant. Correlations between enzyme activity, mRNA expression, and nitrofurazone dose varied with exposure duration. Particularly, the dose-responses showed different dynamics depending on either endpoint or exposure duration. Our findings suggest that both the enzyme activity and the gene expression of the tested antioxidant enzymes can be used as biomarkers for ecotoxicological assessment on the premise of ascertaining appropriate dosage scope, exposure duration, endpoint, etc., which can be achieved by using dose-response dynamics. PMID:25628113

  9. Two distinct populations of Bovine IL-17+ T-cells can be induced and WC1+IL-17+?? T-cells are effective killers of protozoan parasites

    PubMed Central

    Peckham, R. K.; Brill, R.; Foster, D. S.; Bowen, A. L.; Leigh, J. A.; Coffey, T. J.; Flynn, R. J.

    2014-01-01

    IL-17 has emerged as a key player in the immune system, exhibiting roles in protection from infectious diseases and promoting inflammation in autoimmunity. Initially thought to be CD4 T-cell-derived, the sources of IL-17 are now known to be varied and belong to both the innate and adaptive arms of the immune system. Mechanisms for inducing IL-17 production in lymphoid cells are thought to rely on appropriate antigenic stimulation in the context of TGF-?1, IL-6 and/or IL-1?. Using culture protocols adapted from human studies, we have effectively induced both bovine CD4+ and WC1+ ?? T-cells to produce IL-17 termed Th17 and ??17 cells, respectively. The negative regulatory effect of IFN-? on mouse and human IL-17 production can be extended to the bovine model, as addition of IFN-? decreases IL-17 production in both cell types. Furthermore we show that infection with the protozoan Neospora caninum will induce fibroblasts to secrete pro-IL-17 factors thereby inducing a ??17 phenotype that preferentially kills infected target cells. Our study identifies two T-cell sources of IL-17, and is the first to demonstrate a protective effect of IL-17+ T-cells in ruminants. Our findings offer further opportunities for future adjuvants or vaccines which could benefit from inducing these responses. PMID:24961164

  10. A Non-Long Terminal Repeat Retrotransposon Family Is Restricted to the Germ Line Micronucleus of the Ciliated Protozoan Tetrahymena thermophila

    PubMed Central

    Fillingham, Jeffrey S.; Thing, Trine A.; Vythilingum, Nama; Keuroghlian, Alex; Bruno, Deanna; Golding, G. Brian; Pearlman, Ronald E.

    2004-01-01

    The ciliated protozoan Tetrahymena thermophila undergoes extensive programmed DNA rearrangements during the development of a somatic macronucleus from the germ line micronucleus in its sexual cycle. To investigate the relationship between programmed DNA rearrangements and transposable elements, we identified several members of a family of non-long terminal repeat (LTR) retrotransposons (retroposons) in T. thermophila, the first characterized in the ciliated protozoa. This multiple-copy retrotransposon family is restricted to the micronucleus of T. thermophila. The REP (Tetrahymena non-LTR retroposon) elements encode an ORF2 typical of non-LTR elements that contains apurinic/apyrimidinic endonuclease (APE) and reverse transcriptase (RT) domains. Phylogenetic analysis of the RT and APE domains indicates that the element forms a deep-branching clade within the non-LTR retrotransposon family. Northern analysis with a probe to the conserved RT domain indicates that transcripts from the element are small and heterogeneous in length during early macronuclear development. The presence of a repeated transposable element in the genome is consistent with the model that programmed DNA deletion in T. thermophila evolved as a method of eliminating deleterious transposons from the somatic macronucleus. PMID:14871946

  11. Characterization of a defensin from the sand fly Phlebotomus duboscqi induced by challenge with bacteria or the protozoan parasite Leishmania major.

    PubMed

    Boulanger, Nathalie; Lowenberger, Carl; Volf, Petr; Ursic, Raul; Sigutova, Lucie; Sabatier, Laurence; Svobodova, Milena; Beverley, Stephen M; Späth, Gerald; Brun, Reto; Pesson, Bernard; Bulet, Philippe

    2004-12-01

    Antimicrobial peptides are major components of the innate immune response of epithelial cells. In insect vectors, these peptides may play a role in the control of gut pathogens. We have analyzed antimicrobial peptides produced by the sand fly Phlebotomus duboscqi, after challenge by injected bacteria or feeding with bacteria or the protozoan parasite Leishmania major. A new hemolymph peptide with antimicrobial activity was identified and shown to be a member of the insect defensin family. Interestingly, this defensin exhibits an antiparasitic activity against the promastigote forms of L. major, which reside normally within the sand fly midgut. P. duboscqi defensin could be induced by both hemolymph or gut infections. Defensin mRNA was induced following infection by wild-type L. major, and this induction was much less following infections with L. major knockout mutants that survive poorly in sand flies, due to specific deficiencies in abundant cell surface glycoconjugates containing phosphoglycans (including lipophosphoglycan). The ability of gut pathogens to induce gut as well as fat body expression of defensin raises the possibility that this antimicrobial peptide might play a key role in the development of parasitic infections. PMID:15557638

  12. Time-Lapse Video Microscopy of Gliding Motility in Toxoplasma gondii Reveals a Novel, Biphasic Mechanism of Cell Locomotionh V

    Microsoft Academic Search

    Sebastian Håkansson; Hiroshi Morisaki; John Heuser; L. David Sibley

    Toxoplasma gondii is a member of the phylum Apicomplexa, a diverse group of intracellular parasites that share a unique form of gliding motility. Gliding is substrate dependent and occurs without apparent changes in cell shape and in the absence of traditional locomotory organelles. Here, we demonstrate that gliding is characterized by three distinct forms of motility: circular gliding, upright twirling,

  13. Gliding motility: An efficient mechanism for cell penetration

    Microsoft Academic Search

    L. David Sibley; Sebastian Håkansson; Vern B Carruthers

    1998-01-01

    An important group of animal and human pathogens, belonging to the phylum Apicomplexa, employs a novel form of motility, known as gliding, to move on solid substrates and to enter host cells. Gliding is dependent on the parasite cytoskeleton and involves a conserved family of secretory adhesins.

  14. Evidence for the shikimate pathway in apicomplexan parasites

    Microsoft Academic Search

    Fiona Roberts; Craig W. Roberts; Jennifer J. Johnson; Dennis E. Kyle; Tino Krell; John R. Coggins; Graham H. Coombs; Wilbur K. Milhous; Saul Tzipori; David J. P. Ferguson; Debopam Chakrabarti; Rima McLeod

    1998-01-01

    Parasites of the phylum Apicomplexa cause substantial morbidity, mortality and economic losses, and new medicines to treat them are needed urgently,. The shikimate pathway is an attractive target for herbicides and antimicrobial agents because it is essential in algae, higher plants, bacteria and fungi, but absent from mammals,. Here we present biochemical, genetic and chemotherapeutic evidence for the presence of

  15. Advances in Cryptosporidium Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Cryptosporidium is one of over 300 genera that include 4800 named species in the phylum Apicomplexa. There are 16 species of Cryptosporidium and nearly 40 unnamed cryptosporidia called genotypes based on significant rRNA or other gene sequence differences. A genotype is a temporary descrip...

  16. Heliophrya sp. , a new protozoan biomonitor of pollution: culture techniques, toxin uptake and elimination, and field studies in an oil-polluted stream

    SciTech Connect

    Sayre, P.G.

    1984-01-01

    The stalkless suctorian Heliophyra sp., a sessile ciliated protozoan, was used as a pollution biomonitor. The research objectives were to determine: (1) optimal culture conditions and techniques for biotoxicity testing; (2) ability of Helipophrya to incorporate and eliminate a /sup 14/C oil component and other organic toxins; (3) suitability of Heliophrya as a biomonitor of oil pollution. Selection of culture conditions for Heliophrya were based on survival over a three week period and ability to divide when fed after three weeks. The LC50 (lethal concentration for 50% of the population) for 96 h was 12.4 ppt salinity. Heliophrya were exposed to /sup 14/C toxins for 48 h, then organisms were transferred to nonradioactive water for 96 h. The uptake rate of /sup 14/C octachlorostyrene was higher than /sup 14/C phenanthrene or /sup 14/C diisononyl phthalate. Elimination rates were comparable to other test organisms. Heliophrya and d. pulex were placed at three stations, in a stream which received chronic oil pollution, for periods of 48 h and seven days. A 48 h lab test with dilutions of field water was performed. Water samples were analyzed by gas chromatography and mass spectrometry. Death of Heliophrya at the three polluted stations over 48 h was not significantly greater than at a less polluted tributary; however, all the Daphnia in the polluted stream stations were killed. In the seven day field study, Heliophrya had an estimated LC50 of 1 ppm for the aromatic and 29 ppm for the total hydrocarbons. Compared to other species, Heliophrya is moderately sensitive to oil pollution, and is a good companion biomonitor to the more sensitive Daphnia.

  17. Metabolome Analysis Revealed Increase in S-Methylcysteine and Phosphatidylisopropanolamine Synthesis upon l-Cysteine Deprivation in the Anaerobic Protozoan Parasite Entamoeba histolytica*

    PubMed Central

    Husain, Afzal; Sato, Dan; Jeelani, Ghulam; Mi-ichi, Fumika; Ali, Vahab; Suematsu, Makoto; Soga, Tomoyoshi; Nozaki, Tomoyoshi

    2010-01-01

    l-Cysteine is ubiquitous in all living organisms and is involved in a variety of functions, including the synthesis of iron-sulfur clusters and glutathione and the regulation of the structure, stability, and catalysis of proteins. In the protozoan parasite Entamoeba histolytica, the causative agent of amebiasis, l-cysteine plays an essential role in proliferation, adherence, and defense against oxidative stress; however, the essentiality of this amino acid in the pathways it regulates is not well understood. In the present study, we applied capillary electrophoresis time-of-flight mass spectrometry to quantitate charged metabolites modulated in response to l-cysteine deprivation in E. histolytica, which was selected as a model for examining the biological roles of l-cysteine. l-Cysteine deprivation had profound effects on glycolysis, amino acid, and phospholipid metabolism, with sharp decreases in the levels of l-cysteine, l-cystine, and S-adenosylmethionine and a dramatic accumulation of O-acetylserine and S-methylcysteine. We further demonstrated that S-methylcysteine is synthesized from methanethiol and O-acetylserine by cysteine synthase, which was previously considered to be involved in sulfur-assimilatory l-cysteine biosynthesis. In addition, l-cysteine depletion repressed glycolysis and energy generation, as it reduced acetyl-CoA, ethanol, and the major nucleotide di- and triphosphates, and led to the accumulation of glycolytic intermediates. Interestingly, l-cysteine depletion increased the synthesis of isopropanolamine and phosphatidylisopropanolamine, and it was confirmed that their increment was not a result of oxidative stress but was a specific response to l-cysteine depletion. We also identified a pathway in which isopropanolamine is synthesized from methylglyoxal via aminoacetone. To date, this study represents the first case where l-cysteine deprivation leads to drastic changes in core metabolic pathways, including energy, amino acid, and phospholipid metabolism. PMID:20923776

  18. Long-term exposure of bacterial and protozoan communities to TiO2 nanoparticles in an aerobic-sequencing batch reactor

    NASA Astrophysics Data System (ADS)

    Supha, Chitpisud; Boonto, Yuphada; Jindakaraked, Manee; Ananpattarachai, Jirapat; Kajitvichyanukul, Puangrat

    2015-06-01

    Titanium dioxide (TiO2) nanopowders at different concentrations (0–50 mg L?1) were injected into an aerobic-sequencing batch reactor (SBR) to investigate the effects of long-term exposure to nanoparticles on bacterial and protozoan communities. The detection of nanoparticles in the bioflocs was analyzed by scanning electron microscopy, transmission electron microscopy, and energy-dispersive x-ray spectroscopy. The SBR wastewater experiments were conducted under the influence of ultraviolet light with photocatalytic TiO2. The intrusion of TiO2 nanoparticles was found both on the surface and inside of the bioflocs. The change of microbial population in terms of mixed liquor-suspended solids and the sludge volume index was monitored. The TiO2 nanoparticles tentatively exerted an adverse effect on the microbial population, causing the reduction of microorganisms (both bacteria and protozoa) in the SBR. The respiration inhibition rate of the bacteria was increased, and the viability of the microbial population was reduced at the high concentration (50 mg L?1) of TiO2. The decreasing number of protozoa in the presence of TiO2 nanoparticles during 20 days of treatment with 0.5 and 1.0 mg L?1 TiO2 is clearly demonstrated. The measured chemical oxygen demand (COD) in the effluent tends to increase with a long-term operation. The increase of COD in the system suggests a decrease in the efficiency of the wastewater treatment plant. However, the SBR can effectively remove the TiO2 nanoparticles (up to 50 mg L?1) from the effluent.

  19. Flow cytometry assessment of cytotoxicity and reactive oxygen species generation by single and binary mixtures of cadmium, zinc and copper on populations of the ciliated protozoan Tetrahymena thermophila.

    PubMed

    Gallego, Andrea; Martín-González, Ana; Ortega, Ruth; Gutiérrez, Juan C

    2007-06-01

    In the present study, we have assessed by flow cytometry, the cytotoxicity of the heavy metals Cd, Zn and Cu on populations of the ciliated protozoan Tetrahymena thermophila. The obtained LC(50) for these metals was estimated as 0.195mgCdl(-1), 3.58mgZnl(-1) and 0.47mgCul(-1), respectively. As a result, the toxicity rank for this eukaryotic microorganism is Cd>Cu>Zn. Using the same methodology and the Concentration Addition approach, the toxicity of binary mixtures of these metals was evaluated in order to detect the type of interaction between these metals. Results indicated that antagonism is the predominant interaction but it can change to additivity or even to synergism at high metal concentrations. Besides, the concentration ratio between metals plays also a crucial role in determining the type of metallic interaction, at least in Tetrahymena. Cytotoxicity data from single and bimetallic mixtures have been compared with those from selected microalgae, other species of ciliates, fish and mammalian cell lines and metazoan. By other hand, we have detected the mitochondrial generation of peroxides induced by both single and binary treatments with Cd, Zn and Cu on populations of Tetrahymena, using the specific fluorophore dyhidrorhodamine. The nature and concentrations of metal as well as the metallic ratio were important factors in reactive oxygen species production. All results found in T. thermophila are compared with previous reports in other organisms and, some explanations and hypothesis to support results are given, including the involvement of metallothioneins as antioxidants and their role in the binding of metal cations. PMID:17397902

  20. Bacterial Protein Structures Reveal Phylum Dependent Divergence

    PubMed Central

    Shortridge, Matthew D.; Triplet, Thomas; Revesz, Peter; Griep, Mark A.; Powers, Robert

    2011-01-01

    Protein sequence space is vast compared to protein fold space. This raises important questions about how structures adapt to evolutionary changes in protein sequences. A growing trend is to regard protein fold space as a continuum rather than a series of discrete structures. From this perspective, homologous protein structures within the same functional classification should reveal a constant rate of structural drift relative to sequence changes. The clusters of orthologous groups (COG) classification system was used to annotate homologous bacterial protein structures in the Protein Data Bank (PDB). The structures and sequences of proteins within each COG were compared against each other to establish their relatedness. As expected, the analysis demonstrates a sharp structural divergence between the bacterial phyla Firmicutes and Proteobacteria. Additionally, each COG had a distinct sequence/structure relationship, indicating that different evolutionary pressures affect the degree of structural divergence. However, our analysis also shows the relative drift rate between sequence identity and structure divergence remains constant. PMID:21315656

  1. RNA interference in protozoan parasites

    Microsoft Academic Search

    Elisabetta Ullu; Christian Tschudi; Tirtha Chakraborty

    2004-01-01

    Summary RNA interference or RNAi is defined as the mecha- nism through which gene-specific, double-stranded RNA (dsRNA) triggers degradation of homologous transcripts. Besides providing an invaluable tool to downregulate gene expression in a variety of organ- isms, it is now evident that RNAi extends its tentacles into both the nucleus and the cytoplasm and is involved in a variety of

  2. Multiple Functionally Redundant Signals Mediate Targeting to the Apicoplast in the Apicomplexan Parasite Toxoplasma gondii

    PubMed Central

    Harb, Omar S.; Chatterjee, Bithi; Fraunholz, Martin J.; Crawford, Michael J.; Nishi, Manami; Roos, David S.

    2004-01-01

    Most species of the protozoan phylum Apicomplexa harbor an endosymbiotic organelle—the apicoplast—acquired when an ancestral parasite engulfed a eukaryotic plastid-containing alga. Several hundred proteins are encoded in the parasite nucleus and are posttranslationally targeted to the apicoplast by a distinctive bipartite signal. The N-terminal 20 to 30 amino acids of nucleus-encoded apicoplast targeted proteins function as a classical signal sequence, mediating entry into the secretory pathway. Cleavage of the signal sequence exposes a transit peptide of variable length (50 to 200 amino acids) that is required for directing proteins to the apicoplast. Although these peptides are enriched in basic amino acids, their structural and functional characteristics are not well understood, which hampers the identification of apicoplast proteins that may constitute novel chemotherapeutic targets. To identify functional domains for a model apicoplast transit peptide, we generated more than 80 deletions and mutations throughout the transit peptide of Toxoplasma gondii ferredoxin NADP+ reductase (TgFNR) and examined the ability of these altered transit peptides to mediate proper targeting and processing of a fluorescent protein reporter. These studies revealed the presence of numerous functional domains. Processing can take place at multiple sites in the protein sequence and may occur outside of the apicoplast lumen. The TgFNR transit peptide contains at least two independent and functionally redundant targeting signals, each of which contains a subdomain that is required for release from or proper sorting within the endoplasmic reticulum. Certain deletion constructs traffic to multiple locations, including the apicoplast periphery, the rhoptries, and the parasitophorous vacuole, suggesting a common thread for targeting to these specialized compartments. PMID:15189987

  3. Cats and Toxoplasma gondii: A systematic review and meta-analysis in Iran.

    PubMed

    Rahimi, Mohammad T; Daryani, Ahmad; Sarvi, Shahabeddin; Shokri, Azar; Ahmadpour, Ehsan; Teshnizi, Saeed H; Mizani, Azade; Sharif, Mahdi

    2015-01-01

    Toxoplasma gondii is a cosmopolitan zoonotic intracellular coccidian of the phylum Apicomplexa infecting warm-blooded animals and human beings. This protozoan causes a significant public health problem in humans and imposes considerable economic losses and damages to husbandry industries. The final host, cats, accounts for all of these significant burdens. Hence the present study was designed to analyse and review the overall prevalence rate of T. gondii infection in cats in Iran for the first time. In the present study data collection (published and unpublished papers, abstracts of proceedings of national parasitology congresses and dissertations) was systematically undertaken on electronic databases including PubMed, Google Scholar, Ebsco, Science Direct, Scopus, Magiran, Irandoc, IranMedex and Scientific Information Database. A total of 21 studies from 1975 to 2013 reporting prevalence of Toxoplasma infection in cats from different areas in Iran met the eligibility criteria. The pooled proportion of toxoplasmosis using the random-effect model amongst cats was estimated at 33.6% (95% confidence interval [CI] 22.05-46.41). The prevalence rate of cat toxoplasmosis in various regions of Iran ranged from 1.2% to 89.2%. Firstly, this study establishes a crude prevalence rate of T. gondii infection in cats. Secondly, it discusses the role of significant risk factors including sex, age and being either household or stray cats, in the epidemiology of the disease. Furthermore, the current study determines gaps and drawbacks in the prior studies that are useful to keep in mind to assist in designing more accurate investigations in future. PMID:26017063

  4. The parasite specific substitution matrices improve the annotation of apicomplexan proteins

    PubMed Central

    2012-01-01

    Background A number of apicomplexan genomes have been sequenced successfully in recent years and this would help in understanding the biology of apicomplexan parasites. The members of the phylum Apicomplexa are important protozoan parasites (Plasmodium, Toxoplasma and Cryptosporidium etc) that cause some of the deadly diseases in humans and animals. In our earlier studies, we have shown that the standard BLOSUM matrices are not suitable for compositionally biased apicomplexan proteins. So we developed a novel series (SMAT and PfFSmat60) of substitution matrices which performed better in comparison to standard BLOSUM matrices and developed ApicoAlign, a sequence search and alignment tool for apicomplexan proteins. In this study, we demonstrate the higher specificity of these matrices and make an attempt to improve the annotation of apicomplexan kinases and proteases. Results The ROC curves proved that SMAT80 performs best for apicomplexan proteins followed by compositionally adjusted BLOSUM62 (PSI-BLAST searches), BLOSUM90 and BLOSUM62 matrices in terms of detecting true positives. The poor E-values and/or bit scores given by SMAT80 matrix for the experimentally identified coccidia-specific oocyst wall proteins against hematozoan (non-coccidian) parasites further supported the higher specificity of the same. SMAT80 uniquely detected (missed by BLOSUM) orthologs for 1374 apicomplexan hypothetical proteins against SwissProt database and predicted 70 kinases and 17 proteases. Further analysis confirmed the conservation of functional residues of kinase domain in one of the SMAT80 detected kinases. Similarly, one of the SMAT80 detected proteases was predicted to be a rhomboid protease. Conclusions The parasite specific substitution matrices have higher specificity for apicomplexan proteins and are helpful in detecting the orthologs missed by BLOSUM matrices and thereby improve the annotation of apicomplexan proteins which are hypothetical or with unknown function. PMID:23281791

  5. LIFE CYCLE OF CALYPTOSPORA FUNDULI (APICOMPLEXA: CALYPTOSPORIDAE)

    EPA Science Inventory

    The taxonomic status of the extraintestinal piscine coccidium Calyptospora funduli is based in part on its requirement of an intermediate host (the daggerblade grass shrimp, Palaemonetes pugio). In this study, grass shrimp fed livers of Gulf killifish (Fundulus grandis) infected ...

  6. CALYPTOSPORA FUNDULI (APICOMPLEXA): LIFE CYCLE AND TAXONOMY

    EPA Science Inventory

    The taxonomic status of the extraintestinal piscine coccidium Calyptospora funduli is based in part on its requirement of an intermediate host (the daggerblade grass shrimp, Palaemonetes pugio). Grass shrimp fed livers of Gulf killifish (Fundulus grandis) infected with sporulated...

  7. Two Atypical l-Cysteine-regulated NADPH-dependent Oxidoreductases Involved in Redox Maintenance, l-Cystine and Iron Reduction, and Metronidazole Activation in the Enteric Protozoan Entamoeba histolytica*

    PubMed Central

    Jeelani, Ghulam; Husain, Afzal; Sato, Dan; Ali, Vahab; Suematsu, Makoto; Soga, Tomoyoshi; Nozaki, Tomoyoshi

    2010-01-01

    We discovered novel catalytic activities of two atypical NADPH-dependent oxidoreductases (EhNO1/2) from the enteric protozoan parasite Entamoeba histolytica. EhNO1/2 were previously annotated as the small subunit of glutamate synthase (glutamine:2-oxoglutarate amidotransferase) based on similarity to authentic bacterial homologs. As E. histolytica lacks the large subunit of glutamate synthase, EhNO1/2 were presumed to play an unknown role other than glutamine/glutamate conversion. Transcriptomic and quantitative reverse PCR analyses revealed that supplementation or deprivation of extracellular l-cysteine caused dramatic up- or down-regulation, respectively, of EhNO2, but not EhNO1 expression. Biochemical analysis showed that these FAD- and 2[4Fe-4S]-containing enzymes do not act as glutamate synthases, a conclusion which was supported by phylogenetic analyses. Rather, they catalyze the NADPH-dependent reduction of oxygen to hydrogen peroxide and l-cystine to l-cysteine and also function as ferric and ferredoxin-NADP+ reductases. EhNO1/2 showed notable differences in substrate specificity and catalytic efficiency; EhNO1 had lower Km and higher kcat/Km values for ferric ion and ferredoxin than EhNO2, whereas EhNO2 preferred l-cystine as a substrate. In accordance with these properties, only EhNO1 was observed to physically interact with intrinsic ferredoxin. Interestingly, EhNO1/2 also reduced metronidazole, and E. histolytica transformants overexpressing either of these proteins were more sensitive to metronidazole, suggesting that EhNO1/2 are targets of this anti-amebic drug. To date, this is the first report to demonstrate that small subunit-like proteins of glutamate synthase could play an important role in redox maintenance, l-cysteine/l-cystine homeostasis, iron reduction, and the activation of metronidazole. PMID:20592025

  8. Seasonality of gregarine parasitism in the damselfly, Nehalennia irene : understanding unimodal patterns

    Microsoft Academic Search

    Mark R. Forbes; Julia J. Mlynarek; Jane Allison; Kerry R. Hecker

    We studied parasitism by gut protozoans (Apicomplexa: Eugregarinidae) in the damselfly, Nehalennia irene (Hagen) (Odonata: Coenagrionidae). We tested whether there was any seasonal pattern, as has been found for other parasites\\u000a of damselflies and which has implications for selection on emergence and breeding. Using aggregate data from 12 date-by-site\\u000a comparisons involving five sites, we found that both prevalence and intensity

  9. Variability of haemocyte and haemolymph parameters in European flat oyster Ostrea edulis families obtained from brood stocks of different geographical origins and relation with infection by the protozoan Bonamia ostreae.

    PubMed

    Mirella da Silva, Patricia; Comesaña, Pilar; Fuentes, José; Villalba, Antonio

    2008-05-01

    A research project to compare productive traits (growth and mortality), disease susceptibility and immune capability between Ostrea edulis stocks was performed. This article reports the results on the immune capability and its relation with infection by the intrahaemocytic protozoan Bonamia ostreae. Four to five oyster spat families were produced from each of four European flat oyster populations (one from Ireland, one from Greece and two from Galicia, Spain) in a hatchery. The spat were transferred to a raft in the Ría de Arousa (Galicia) for on growing for 2 years. Total haemocyte count (THC) and differential haemocyte count (DHC) were estimated monthly through the second year of growing-out. Three types of haemocytes were distinguished: granulocytes (GH), large hyalinocytes (LHH) and small hyalinocytes (SHH). Significant correlations between the mean relative abundance of GH and SHH of the families and the mean prevalence of B. ostreae, the overall incidence of pathological conditions and the cumulative mortality of the families were found; these correlations supported the hypothesis that high %GH and low %SHH would enhance oyster immune ability and, consequently, would contribute to lower susceptibility to disease and longer lifespan. Infection by B. ostreae involved a significant increase of circulating haemocytes, which affected more markedly the LHH type. The higher the infection intensity the higher the %LHH. This illustrates the ability of B. ostreae to modulate the immune responses of the O. edulis to favour its own multiplication. A significant reduction of the phenoloxidase activity in the haemolymph of oysters O. edulis infected by B. ostreae was observed. Nineteen enzymatic activities in the haemolymph of O. edulis and Crassostrea gigas (used as a B. ostreae resistant reference) were measured using the kit api ZYM, Biomerieux. Qualitative and quantitative differences in enzyme activities in both haemocyte and plasma fractions between B. ostreae noninfected O. edulis from different origins were recorded. However, no clear positive association between enzyme activity and susceptibility to bonamiosis was found. The only enzyme detected in the resistant species C. gigas that was not found in the susceptible one O. edulis was beta-glucosidase (in plasma). B. ostreae infected O. edulis showed significant increase of some enzyme activities and the occurrence of enzymes that were not detected in noninfected oysters. These changes could be due to infection-induced enzyme synthesis by the host or to enzyme synthesis by the parasite. PMID:18329903

  10. Macronuclear Duplication in the Ciliated Protozoan Euplotes

    Microsoft Academic Search

    JOSEPH G. GALL

    1959-01-01

    The ribbon-like macronucleus of Euplotes euryslomus pinches in half ami- totically at each cell division. Several hours before the actual division two lightly staining duplication bands (reorganization bands) appear at the ends of the nu- cleus and approach each other slowly, finally meeting near the middle. Distal to the bands, that is, in regions through which the bands have already

  11. Osmoregulation in the Parasitic Protozoan Tritrichomonas foetus

    Microsoft Academic Search

    Sarah L. Maroulis; Philip J. Schofield; Michael R. Edwards

    2003-01-01

    Tritrichomonas foetus was shown to undergo a regulatory volume increase (RVI) when it was subjected to hyperosmotic challenge, but there was no regulatory volume decrease after hypoosmotic challenge, as deter- mined by using both light-scattering methods and measurement of intracellular water space to monitor cell volume. An investigation of T. foetus intracellular amino acids revealed a pool size (65 mM)

  12. Osmoregulation in the Parasitic Protozoan Tritrichomonas foetus

    PubMed Central

    Maroulis, Sarah L.; Schofield, Philip J.; Edwards, Michael R.

    2003-01-01

    Tritrichomonas foetus was shown to undergo a regulatory volume increase (RVI) when it was subjected to hyperosmotic challenge, but there was no regulatory volume decrease after hypoosmotic challenge, as determined by using both light-scattering methods and measurement of intracellular water space to monitor cell volume. An investigation of T. foetus intracellular amino acids revealed a pool size (65 mM) that was similar to that of Trichomonas vaginalis but was considerably smaller than those of Giardia intestinalis and Crithidia luciliae. Changes in amino acid concentrations in response to hyperosmotic challenge were found to account for only 18% of the T. foetus RVI. The T. foetus intracellular sodium and potassium concentrations were determined to be 35 and 119 mM, respectively. The intracellular K+ concentration was found to increase considerably during exposure to hyperosmotic stress, and, assuming that there was a monovalent accompanying anion, this increase was estimated to account for 87% of the RVI. By using light scattering it was determined that the T. foetus RVI was enhanced by elevated external K+ concentrations and was inhibited when K+ and/or Cl? was absent from the medium. The results suggested that the well-documented Na+-K+-2Cl? cotransport system was responsible for the K+ influx activated during the RVI. However, inhibitors of Na+-K+-2Cl? cotransport in other systems, such as quinine, ouabain, furosemide, and bumetanide, had no effect on the RVI or K+ influx in T. foetus. PMID:12902238

  13. Review article Protozoan infections (Toxoplasma gondii, Neospora

    E-print Network

    Paris-Sud XI, Université de

    is a serious cause of fetal mortality in sheep and goats. Oocysts, the parasite stage responsible the cause of death. Control relies on preventing contamination of pasture and water with faeces of dogs

  14. Protozoan growth rates in Antarctic lakes

    Microsoft Academic Search

    Johanna Laybourn-Parry; Elanor M. Bell; Emily C. Roberts

    2000-01-01

    The growth rates of heterotrophic nanoflagellates (HNAN), mixotrophic cryptophytes, dinoflagellates and ciliates in field\\u000a assemblages from Ace Lake in the Vestfold Hills (eastern Antarctica) and Lakes Fryxell and Hoare (McMurdo Dry Valleys, western\\u000a Antarctica), were determined during the austral summers of 1996\\/1997 and 1997\\/1998. The response of the nanoflagellates to\\u000a temperature differed between lakes in eastern and western Antarctica. In

  15. Emerging Food- and Waterborne Protozoan Diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cryptosporidium, Cyclospora and Toxoplasma are related apicomplexan parasites transmitted to humans worldwide through ingestion of contaminated food and drinking water. Of 15 species of Cryptosporidium- C parvum, C. hominis, C and C. meleagridis are the most prevalent infections in humans and the la...

  16. Are the green algae (phylum Viridiplantae) two billion years old?

    Microsoft Academic Search

    Bernard TEYSSÈDRE

    2006-01-01

    In his book, Life on a young planet, A.H. KNOLL states that the first documented fossils of green algae date back 750 Ma. However, according to B. TEYSSÈDRE's book, La vie invisible, they are much older. Using a method which combines paleontology and molecular phylogeny, this paper is an inquiry into the Precambrian fossils of some \\

  17. p63 gene structure in the phylum mollusca.

    PubMed

    Bari?evi?, Ana; Štifani?, Mauro; Hamer, Bojan; Batel, Renato

    2015-08-01

    Roles of p53 family ancestor (p63) in the organisms' response to stressful environmental conditions (mainly pollution) have been studied among molluscs, especially in the genus Mytilus, within the last 15years. Nevertheless, information about gene structure of this regulatory gene in molluscs is scarce. Here we report the first complete genomic structure of the p53 family orthologue in the mollusc Mediterranean mussel Mytilus galloprovincialis and confirm its similarity to vertebrate p63 gene. Our searches within the available molluscan genomes (Aplysia californica, Lottia gigantea, Crassostrea gigas and Biomphalaria glabrata), found only one p53 family member present in a single copy per haploid genome. Comparative analysis of those orthologues, additionally confirmed the conserved p63 gene structure. Conserved p63 gene structure can be a helpful tool to complement or/and revise gene annotations of any future p63 genomic sequence records in molluscs, but also in other animal phyla. Knowledge of the correct gene structure will enable better prediction of possible protein isoforms and their functions. Our analyses also pointed out possible mis-annotations of the p63 gene in sequenced molluscan genomes and stressed the value of manual inspection (based on alignments of cDNA and protein onto the genome sequence) for a reliable and complete gene annotation. PMID:25936268

  18. A novel multi-domain mucin-like glycoprotein of Cryptosporidium parvum mediates invasion 1 Note: Nucleotide sequence data reported in this paper are available in the EMBL, GenBank™ and DDJB databases under the accession number AF068065. 1 , 2 A portion of the amino acid sequence of GP900 was presented at the 47th annual meeting of the Society of Protozoologists and 3rd Workshop on opportunistic Protozoan Pathogens in Cleveland, Ohio, June 1994. 2

    Microsoft Academic Search

    Debra A Barnes; Alain Bonnin; Jin-Xing Huang; Laurent Gousset; Jie Wu; Jiri Gut; Patricia Doyle; Jean-Francois Dubremetz; Honorine Ward; Carolyn Petersen

    1998-01-01

    Cryptosporidium parvum is a protozoan parasite which produces self-limited disease in immunocompetent hosts and devastating, persistent diarrhea in immunocompromised individuals. There is no effective treatment for cryptosporidiosis and little is known about the basic biology of the organism. Cloning and sequence analysis of the gene encoding GP900, a previously identified >900 kDa glycoprotein, predicts a mucin-like glycoprotein composed of distal

  19. Identification of T. gondii Myosin Light Chain-1 as a Direct Target of TachypleginA-2, a Small-Molecule Inhibitor of Parasite Motility and Invasion

    PubMed Central

    Leung, Jacqueline M.; Tran, Fanny; Pathak, Ravindra B.; Poupart, Séverine; Heaslip, Aoife T.; Ballif, Bryan A.; Westwood, Nicholas J.; Ward, Gary E.

    2014-01-01

    Motility of the protozoan parasite Toxoplasma gondii plays an important role in the parasite’s life cycle and virulence within animal and human hosts. Motility is driven by a myosin motor complex that is highly conserved across the Phylum Apicomplexa. Two key components of this complex are the class XIV unconventional myosin, TgMyoA, and its associated light chain, TgMLC1. We previously showed that treatment of parasites with a small-molecule inhibitor of T. gondii invasion and motility, tachypleginA, induces an electrophoretic mobility shift of TgMLC1 that is associated with decreased myosin motor activity. However, the direct target(s) of tachypleginA and the molecular basis of the compound-induced TgMLC1 modification were unknown. We show here by “click” chemistry labelling that TgMLC1 is a direct and covalent target of an alkyne-derivatized analogue of tachypleginA. We also show that this analogue can covalently bind to model thiol substrates. The electrophoretic mobility shift induced by another structural analogue, tachypleginA-2, was associated with the formation of a 225.118 Da adduct on S57 and/or C58, and treatment with deuterated tachypleginA-2 confirmed that the adduct was derived from the compound itself. Recombinant TgMLC1 containing a C58S mutation (but not S57A) was refractory to click labelling and no longer exhibited a mobility shift in response to compound treatment, identifying C58 as the site of compound binding on TgMLC1. Finally, a knock-in parasite line expressing the C58S mutation showed decreased sensitivity to compound treatment in a quantitative 3D motility assay. These data strongly support a model in which tachypleginA and its analogues inhibit the motility of T. gondii by binding directly and covalently to C58 of TgMLC1, thereby causing a decrease in the activity of the parasite’s myosin motor. PMID:24892871

  20. Cryptosporidium parvum appears to lack a plastid genome.

    PubMed

    Zhu, G; Marchewka, M J; Keithly, J S

    2000-02-01

    Surprisingly, unlike most Apicomplexa, Cryptosporidium parvum appears to lack a plastid genome. Primers based upon the highly conserved plastid small- or large-subunit rRNA (SSU/LSU rRNA) and the tufA-tRNAPhe genes of other members of the phylum Apicomplexa failed to amplify products from intracellular stages of C. parvum, whereas products were obtained from the plastid-containing apicomplexans Eimeria bovis and Toxoplasma gondii, as well as the plants Allium stellatum and Spinacia oleracea. Dot-blot hybridization of sporozoite genomic DNA (gDNA) supported these PCR results. A T. gondii plastid-specific set of probes containing SSU/LSU rRNA and tufA-tRNA(Phe) genes strongly hybridized to gDNA from a diverse group of plastid-containing organisms including three Apicomplexa, two plants, and Euglena gracilis, but not to those without this organelle including C. parvum, three kinetoplastids, the yeast Saccharomyces cerevisiae, mammals and the eubacterium Escherichia coli. Since the origin of the plastid in other apicomplexans is postulated to be the result of a secondary symbiogenesis of either a red or a green alga, the most parsimonious explanation for its absence in C. parvum is that it has been secondarily lost. If confirmed, this would indicate an alternative evolutionary fate for this organelle in one member of the Apicomplexa. It also suggests that unlike the situation with other diseases caused by members of the Apicomplexa, drug development against cryptosporidiosis targeting a plastid genome or metabolic pathways associated with it may not be useful. PMID:10708370

  1. Redescription of the sarcocysts of Sarcocystis rileyi (Apicomplexa: Sarcocystidae).

    PubMed

    Dubey, J P; Cawthorn, R J; Speer, C A; Wobeser, G A

    2003-01-01

    The intermediate hosts for Sarcocystis rileyi (Stiles 1893) Minchin 1913 are ducks (Anas spp.), and the striped skunk (Mephitis mephitis) is its definitive host. The structure of sarcocysts from an experimentally infected shoveler duck (Anas cylpeata) fed sporocysts from an experimentally-infected M. mephitis was studied and compared with type specimens from a naturally infected duck. The experimentally infected duck was killed 154 d after feeding sporocysts. By light microscopy the sarcocyst wall was 3-5 microm thick with indistinct villar protrusions. Ultrastructurally, the sarcocyst wall was a type-23 cyst wall with anastomosing villar protrusions that were up to 7.5 microm long. The villar projections contained filamentous structures. The bradyzoites were 12-14 microm long. Structurally, the sarcocyst from the naturally infected and experimentally infected ducks appeared similar. PMID:14733440

  2. Studies on eimerians (Apicomplexa: Eimeriidae) of wild ruminants.

    PubMed

    Pyziel, Anna

    2012-01-01

    The studies were carried out in W. Stefanski Institute of Parasitology Polish Academy of Sciences. Doctoral thesis defense took place on May 29th 2012. Supervisor: prof. dr hab. Aleksander W. Demiaszkiewicz. PMID:25165763

  3. Life cycle of Hammondia hammondi (Apicomplexa: Sarcocystidae) in cats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hammondia hammondi and Toxoplasma gondii are feline coccidian that are morphologically, antigenically, and phylogenitically related. Both parasites multiply asexually and sexually in feline intestinal enterocytes but H. hammondi remains confined to enterocytes whereas T. gondii also parasitizes extr...

  4. Cryptosporidium xiaoi n. sp. (Apicomplexa: Cryptosporidiidae) in sheep (Ovis aries)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new species, Cryptosporidium xiaoi, is described from sheep. Oocysts of C. xiaoi, previously identified as the Cryptosporidium bovis-like genotype and as the ovine genotype from sheep in Australia and the United States are recorded as such in GenBank (AY587166, EU203216, DQ182597, AY741309, and DQ...

  5. COCCIDIAN PARASITES (APICOMPLEXA: EUCOCCIDORIDA) IN HARDY HEAD FISH, ATHERINOMORUS CAPRICORNENSIS

    EPA Science Inventory

    Authors describe coccidian merozoites (asexual stages) in theexocrine pancreas and oocysts in the gut epithelium of hardy heads,(Woodland) (family Atherinidae) collected at Heron Island, Queensland, Australia, during the pre-ICOPA (International Congress of Parasitology) workshop...

  6. Besnoitia darlingi (Apicomplexa, Sarcocystidae, Toxoplasmatinae): transmission between opossums and cats.

    PubMed

    Smith, D D; Frenkel, J K

    1984-11-01

    Opossums (Didelphis marsupialis), act as intermediate hosts for Besnoitia darlingi and could be infected orally with sporozoites (oocysts) and bradyzoites (tissue cysts), or intraperitoneally (i.p.) with tachyzoites. Infections could presumably be transmitted through cannibalism. Cats (Felis catus), the definitive host, could be infected only with bradyzoites but not sporozoites. Oocysts shed by cats measure about 12 X 12 microns, resemble similarly sized oocysts of Toxoplasma gondii and Hammondia hammondi, and must be differentiated by the appearance of tissue cysts after experimental infection of intermediate hosts. Cats did not form tissue cysts of B. darlingi. Tachyzoites from the related B. jellisoni could be used in the Sabin-Feldman dye test to determine the development of antibody to B. darlingi in opossums after infection. PMID:6439859

  7. Prevalence of Eimeria macusaniensis (Apicomplexa: Eimeriidae) in midwestern Lama spp.

    PubMed

    Jarvinen, J A

    1999-04-01

    To compare the prevalence of Eimeria macusaniensis among midwestern llamas (Lama glama), alpacas (Lama pacos), and guanacos (Lama guanicoe), feces were obtained from Lama spp. in 10 states between October 1989 and February 1996. Feces were examined by centrifugal flotation in sugar solution (specific gravity--1.28-1.30), and oocysts were quantified by a modified McMaster method. Data were compared by host species and age classifications. Typical oocysts occurred in samples from 28% of 76 herds and 10.4% of 443 animals including 12% of 301 llamas, 7% of 115 alpacas, and 7.4% of 27 guanacos. Prevalence was significantly greater (P = 0.009) in animals < 1 yr of age in comparison to older animals for llams (22.1 v.s. 8.5%) and for all Lama spp. combined (17.1 vs. 8.4%). Fecal oocyst abundance was significantly greater (P = 0.001) in llamas < 1 yr of age in comparison to older llamas (30 vs. 16 oocysts per g of feces). Fecal oocyst intensities did not differ significantly. Prevalence in both age groups of midwestern llamas was greater than previously reported for llamas in the western United States. Prevalence in midwestern alpacas < 1 yr of age was lower than reported for alpacas of similar age in South America, but oocyst intensities were similar. These results indicate that infection with E. macusaniensis is more common in Lama spp. in North America than previously recognized. PMID:10219324

  8. The apicoplast: a red alga in human parasites.

    PubMed

    Striepen, Boris

    2011-01-01

    Surprisingly, some of the world's most dangerous parasites appear to have had a benign photosynthetic past in the ocean. The phylum Apicomplexa includes the causative agents of malaria and a number of additional human and animal diseases. These diseases threaten the life and health of hundreds of millions each year and pose a tremendous challenge to public health. Recent findings suggest that Apicomplexa share their ancestry with diatoms and kelps, and that a key event in their evolution was the acquisition of a red algal endosymbiont. A remnant of this endosymbiont is still present today, albeit reduced to a small chloroplast-like organelle, the apicoplast. In the present chapter, I introduce the remarkably complex biology of this organelle. The apicoplast is bounded by four membranes, and these membranes trace their ancestry to three different organisms. Intriguingly, this divergent ancestry is still reflected in their molecular makeup and function. We also pursue the raison d'être of the apicoplast. Why did Apicomplexa retain a chloroplast when they abandoned photosynthesis for a life as obligate parasites? The answer to this question appears to lie in the profound metabolic dependence of the parasite on its endosymbiont. This dependence may prove to be a liability to the parasite. As humans lack chloroplasts, the apicoplast has become one of the prime targets for the development of parasite-specific drugs. PMID:22023445

  9. [Cryptosporidium: phylogeny and taxonomy].

    PubMed

    Chacín-Bonilla, Leonor

    2007-03-01

    Members of the genus Cryptosporidium in the phylum Apicomplexa were long thought to be closely related to the coccidia. However, despite strong morphological similarities to these organisms, Cryptosporidium has notable differences with them and similarities with the gregarine protozoa. On the basis of phylogenetic analysis of molecular data, some authors place Cryptosporidium at the basis of the phylum Apicomplexa, others consider species of this genus to be phylogenetically too distant from the coccidia and do not include them in this group of protozoa, and others think that Cryptosporidium is closely related to gregarines. The taxonomy of this genus and the naming of species are undergoing rapid change due to the new and increasing molecular information. Molecular characterization of oocysts using polymerase chain reaction based procedures has not only a major impact on resolving the taxonomy of Cryptosporidium at the species level but also on the molecular epidemiology of cryptosporidiosis. Today, it is recognized that this genus is a phenotypically and genotypically heterogeneous assemblage of largely morphologically identical species and genotypes. Fourteen Cryptosporidium species and 21 C. parvum genotypes are currently recognized. Phylogenetic analyses have shown that genetically related hosts often have related forms of Cryptosporidium. Application of molecular techniques to taxonomy and epidemiology is helping to characterize new and existing species and determine the sources of the parasites that will facilitate the identification of sources of water-borne cryptosporidiosis. PMID:17432539

  10. Jumbled Genomes: Missing Apicomplexan Synteny

    PubMed Central

    DeBarry, Jeremy D.; Kissinger, Jessica C.

    2011-01-01

    Whole-genome comparisons provide insight into genome evolution by informing on gene repertoires, gene gains/losses, and genome organization. Most of our knowledge about eukaryotic genome evolution is derived from studies of multicellular model organisms. The eukaryotic phylum Apicomplexa contains obligate intracellular protist parasites responsible for a wide range of human and veterinary diseases (e.g., malaria, toxoplasmosis, and theileriosis). We have developed an in silico protein-encoding gene based pipeline to investigate synteny across 12 apicomplexan species from six genera. Genome rearrangement between lineages is extensive. Syntenic regions (conserved gene content and order) are rare between lineages and appear to be totally absent across the phylum, with no group of three genes found on the same chromosome and in the same order within 25 kb up- and downstream of any orthologous genes. Conserved synteny between major lineages is limited to small regions in Plasmodium and Theileria/Babesia species, and within these conserved regions, there are a number of proteins putatively targeted to organelles. The observed overall lack of synteny is surprising considering the divergence times and the apparent absence of transposable elements (TEs) within any of the species examined. TEs are ubiquitous in all other groups of eukaryotes studied to date and have been shown to be involved in genomic rearrangements. It appears that there are different criteria governing genome evolution within the Apicomplexa relative to other well-studied unicellular and multicellular eukaryotes. PMID:21504890

  11. Chemosensory Responses ofaProtozoan Areiedby Modified byAntitubulins

    Microsoft Academic Search

    M. LEVANDOWSKY; D. C. R. HAUSER; M. GLASSGOLD

    1975-01-01

    results wereduetochance) wereseenwith hemin(5x 10-8 to5x 10-5 M),L-fucose (10-6 to 10-4 M),betaine (10-6 to10-5 M),anddimethyl- ,8-propiothetin (10-7 to10-3M),allofwhichoc- curinthevicinity ofrotting seaweeds and could serve aschemical cuesforsuitable natural substrates. Specificity oftheresponses wasseen inthattheanalogues 1)-fucose anddimethyl- acetothetin wereinert (noresponse wasde- tected). Negative response (less tendency to imbed) occurred tocholine (10-7 to10-4M)as choline-hydrochloride, choline bitartrate, and

  12. NERL MICROBIAL PROGRAM WITH EMPHASIS ON PROTOZOAN METHODS

    EPA Science Inventory

    The National Exposure Research Laboratory's facility in Cincinnati is engated in a variety of microbiological research projects that include studies on bacteria, viruses, fungi and protozoa. One of these was a protzoology project to determine the best way to evaluate methods rep...

  13. PROTOZOAN SOURCES OF SPONTANEOUS COLIFORM OCCURRENCE IN CHLORINATED DRINKING WATER

    EPA Science Inventory

    The spontaneous occurrence of coliforms in chlorinated drinking waters has resulted in concern over their potential source and mechanism(s) of introduction into water delivery systems. Previous observations related to protozoal resistance to chlorine coupled with the ingestion of...

  14. Protozoan grazing of bacteria in soil—impact and importance

    Microsoft Academic Search

    Marianne Clarholm

    1981-01-01

    Interactions between bacteria and protozoa in soil were studied over 2-week periods in the field and in a pot experiment.\\u000a Under natural conditions the total biological activity was temporarily synchronized by a large rainfall, and in the laboratory\\u000a by the addition of water to dried-out soil, with or without plants. In the field, peaks in numbers and biomass of bacteria

  15. The trophic response of ciliated protozoans in freshwater lakes

    Microsoft Academic Search

    JOHN R. BEAVER; THOMAS L. CRISMAN

    1982-01-01

    The abundance, biomass, composition, and size distribution of planktonic ciliated proto- zoans were analyzed monthly during 1979 along a trophic gradient represented by 20 Florida lakes. Both the abundance and biomass of ciliates were positively related to trophic state. Eutrophic assemblages were codominated by members of the Scuticociliatida, Oligotrichida, and Haptorida; oligotrophic lakes were dominated principally by the Oligotrichida. In

  16. Drug target identification in intracellular and extracellular protozoan parasites.

    PubMed

    Müller, Joachim; Hemphill, Andrew

    2011-01-01

    The increasing demand for novel anti-parasitic drugs due to resistance formation to well-established chemotherapeutically important compounds has increased the demands for a better understanding of the mechanism(s) of action of existing drugs and of drugs in development. While different approaches have been developed to identify the targets and thus mode of action of anti-parasitic compounds, it has become clear that many drugs act not only on one, but possibly several parasite molecules or even pathways. Ideally, these targets are not present in any cells of the host. In the case of apicomplexan parasites, the unique apicoplast, provides a suitable target for compounds binding to DNA or ribosomal RNA of prokaryotic origin. In the case of intracellular pathogens, a given drug might not only affect the pathogen by directly acting on parasite-associated targets, but also indirectly, by altering the host cell physiology. This in turn could affect the parasite development and lead to parasite death. In this review, we provide an overview of strategies for target identification, and present examples of selected drug targets, ranging from proteins to nucleic acids to intermediary metabolism. PMID:21619514

  17. Protozoan Grazing Increases Mineralization of Naphthalene in Marine Sediment

    Microsoft Academic Search

    Suk-Fong Tso; Gary L. Taghon

    2006-01-01

    Bacterial decomposition of organic matter is frequently enhanced when protozoa are present. Various mechanisms have been proposed to account for this phenomenon, including effects associated with grazing by protozoa (such as increased recycling of limiting nutrients, removal of senescent cells, or reduction of competition among bacteria) and indirect effects of grazers (such as excretion of bacterial growth factors). Few studies

  18. [Common tropical infections with protozoans, worms and ectoparasites].

    PubMed

    Schliemann, S

    2014-10-01

    Infectious diseases of the skin have become rarer in industrialized nations, but they still affect a considerable part of the population in tropical regions. Skin diseases induced by protozoa, worms and ectoparasites are among the 17 "neglected tropical diseases" defined by the WHO (leishmaniasis, dracunculiasis, lymphatic filariasis, onchocerciasis). Skin symptoms in travellers returning from the tropics may challenge dermatologists in Germany regarding differential diagnostic assessment and therapy. Among the 12 most frequent skin diseases in travellers are cutaneous larva migrans, leishmaniasis and myiasis. In this review, diagnosis, treatment and prevention of some the most relevant tropical dermatoses due to protozoa, worms and ectoparasites are discussed. PMID:25217086

  19. Inducible resistance to oxidant stress in the protozoan Leishmania chagasi.

    PubMed

    Miller, M A; McGowan, S E; Gantt, K R; Champion, M; Novick, S L; Andersen, K A; Bacchi, C J; Yarlett, N; Britigan, B E; Wilson, M E

    2000-10-27

    Leishmania sp. protozoa are introduced into a mammalian skin by a sandfly vector, whereupon they encounter increased temperature and toxic oxidants generated during phagocytosis. We studied the effects of 37 degrees C "heat shock" or sublethal menadione, which generates superoxide and hydrogen peroxide, on Leishmania chagasi virulence. Both heat and menadione caused parasites to become more resistant to H(2)O(2)-mediated toxicity. Peroxide resistance was also induced as promastigotes developed in culture from logarithmic to their virulent stationary phase form. Peroxide resistance was not associated with an increase in reduced thiols (trypanothione and glutathione) or increased activity of ornithine decarboxylase, which is rate-limiting in trypanothione synthesis. Membrane lipophosphoglycan increased in size as parasites developed to stationary phase but not after environmental exposures. Instead, parasites underwent a heat shock response upon exposure to heat or sublethal menadione, detected by increased levels of HSP70. Transfection of promastigotes with L. chagasi HSP70 caused a heat-inducible increase in resistance to peroxide, implying it is involved in antioxidant defense. We conclude that leishmania have redundant mechanisms for resisting toxic oxidants. Some are induced during developmental change and others are induced in response to environmental stress. PMID:10931831

  20. Importance of Nonenteric Protozoan Infections in Immunocompromised People

    PubMed Central

    Barratt, J. L. N.; Harkness, J.; Marriott, D.; Ellis, J. T.; Stark, D.

    2010-01-01

    Summary: There are many neglected nonenteric protozoa able to cause serious morbidity and mortality in humans, particularly in the developing world. Diseases caused by certain protozoa are often more severe in the presence of HIV. While information regarding neglected tropical diseases caused by trypanosomatids and Plasmodium is abundant, these protozoa are often not a first consideration in Western countries where they are not endemic. As such, diagnostics may not be available in these regions. Due to global travel and immigration, this has become an increasing problem. Inversely, in certain parts of the world (particularly sub-Saharan Africa), the HIV problem is so severe that diseases like microsporidiosis and toxoplasmosis are common. In Western countries, due to the availability of highly active antiretroviral therapy (HAART), these diseases are infrequently encountered. While free-living amoebae are rarely encountered in a clinical setting, when infections do occur, they are often fatal. Rapid diagnosis and treatment are essential to the survival of patients infected with these organisms. This paper reviews information on the diagnosis and treatment of nonenteric protozoal diseases in immunocompromised people, with a focus on patients infected with HIV. The nonenteric microsporidia, some trypanosomatids, Toxoplasma spp., Neospora spp., some free-living amoebae, Plasmodium spp., and Babesia spp. are discussed. PMID:20930074

  1. Early detection of protozoan grazers in algal biofuel cultures.

    PubMed

    Day, John G; Thomas, Naomi J; Achilles-Day, Undine E M; Leakey, Raymond J G

    2012-06-01

    Future micro-algal biofuels will most likely be derived from open-pond production systems. These are by definition open to "invasion" by grazers, which could devastate micro-algal mass-cultures. There is an urgent requirement for methodologies capable of early detection and control of grazers in dense algal cultures. In this study a model system employing the marine alga Nannochloropsis oculata was challenged by grazers including ciliates, amoebae and a heterotrophic dinoflagellate. A FlowCAM flow-cytometer was used to detect all grazers investigated (size range <20->80 ?m in length) in the presence of algae. Detection limits were <10 cells ml(-1) for both "large" and "small" model grazers, Euplotes vannus (80 × 45 ?m) and an unidentified holotrichous ciliate (~18 × 8 ?m) respectively. Furthermore, the system can distinguish the presence of ciliates in N. oculata cultures with biotechnologically relevant cell densities; i.e. >1.4 × 10(8) cells ml(-1) (>0.5 g l(-1) dry wt.). PMID:22464416

  2. Mineralization of nitrogen by protozoan activity in soil

    Microsoft Academic Search

    P. J. Kuikman

    1990-01-01

    In general, more than 95% of the nitrogen in soils is present in organic forms. This nitrogen is not directly available to plants unless microbial decomposition takes place with the release of mineral nitrogen. In modern agriculture, nitrogen is often applied to arable soils as a fertilizer to support high levels of crop production. Nitrogen is one of the essential

  3. Chitinase Dependent Control of Protozoan Cyst Burden in the Brain

    E-print Network

    2012-01-01

    Flow cytometry BMNCs or splenic cells were incubated with various conjugated antibodies against CXCR3, CD3, CD4, CD8,CD8+ T cells, macrophages (CD45 hi /CD11b+) and microglia (CD45 hi /CD11b+) by flow cytometry.

  4. IMP Dehydrogenase from the Protozoan Parasite Toxoplasma gondii

    PubMed Central

    Sullivan, William J.; Dixon, Stacy E.; Li, Catherine; Striepen, Boris; Queener, Sherry F.

    2005-01-01

    The opportunistic apicomplexan parasite Toxoplasma gondii damages fetuses in utero and threatens immunocompromised individuals. The toxicity associated with standard antitoxoplasmal therapies, which target the folate pathway, underscores the importance of examining alternative pharmacological strategies. Parasitic protozoa cannot synthesize purines de novo; consequently, targeting purine salvage enzymes is a plausible pharmacological strategy. Several enzymes critical to purine metabolism have been studied in T. gondii, but IMP dehydrogenase (IMPDH), which catalyzes the conversion of IMP to XMP, has yet to be characterized. Thus, we have cloned the gene encoding this enzyme in T. gondii. Northern blot analysis shows that two IMPDH transcripts are present in T. gondii tachyzoites. The larger transcript contains an open reading frame of 1,656 nucleotides whose deduced protein sequence consists of 551 amino acids (TgIMPDH). The shorter transcript is an alternative splice product that generates a 371-amino-acid protein lacking the active-site flap (TgIMPDH-S). When TgIMPDH is expressed as a recombinant protein fused to a FLAG tag, the fusion protein localizes to the parasite cytoplasm. Immunoprecipitation with anti-FLAG was employed to purify recombinant TgIMPDH, which converts IMP to XMP as expected. Mycophenolic acid is an uncompetitive inhibitor relative to NAD+, with a intercept inhibition constant (Kii) of 0.03 ± 0.004 ?M. Tiazofurin and its seleno analog were not inhibitory to the purified enzyme, but adenine dinucleotide analogs such as TAD and the nonhydrolyzable ?-methylene derivatives of TAD or SAD were inhibitory, with Kii values 13- to 60-fold higher than that of mycophenolic acid. PMID:15917510

  5. Ecotoxicological effects of graphene oxide on the protozoan Euglena gracilis.

    PubMed

    Hu, Changwei; Wang, Qing; Zhao, Haitao; Wang, Lizhi; Guo, Shaofen; Li, Xiuling

    2015-06-01

    Potential environmental risks posed by nanomaterials increase with their extensive production and application. As a newly emerging carbon material, graphene oxide (GO) exhibits excellent electrochemical properties and has promising applications in many areas. However, the ecotoxicity of GO to organisms, especially aquatic organisms, remains poorly understood. Accordingly, this study examined the toxicity of GO with protozoa Euglena gracilis as test organism. Growth inhibition test was initially performed to investigate acute toxic effects. Protozoa were subsequently exposed to GO ranging from 0.5 mg L(-1) to 5 mg L(-1) for 10 d. The growth, photosynthetic pigment content, activities of antioxidant enzymes, ultrastructure of the protozoa, as well as the shading effect of GO, were analyzed to determine the mechanism of the toxicity effect. Results showed that the 96 h EC50 value of GO in E. gracilis was 3.76±0.74 mg L(-1). GO at a concentration of 2.5 mg L(-1) exerted significant (P<0.01) adverse effects on the organism. These effects were evidenced by the inhibition of growth and the enhancement of malondialdehyde content and antioxidant enzyme activities. Shading effect and oxidative stress may be responsible for GO toxicity. PMID:25703902

  6. Helminth and protozoan parasites in dogs and cats in Belgium.

    PubMed

    Vanparijs, O; Hermans, L; van der Flaes, L

    1991-01-01

    This study investigates the level of helminthic and protozoal infestation over the last 10 years in strays, well-cared-for dogs and cats. Determination of the prevalence of infections was based either on faecal examination or on worm counts at necropsy. Of 2324 faecal flotations (NaCl sp.gr. 1.20) of stray dogs, 34.2% had eggs or proglottids of one or more worm species consisting of Toxocara canis (17.4%), Toxascaris leonina (10.1%), Uncinaria stenocephala (11.4%), Trichuris vulpis (7.0%) and cestodes (2.1%). Isospora oocysts were observed in 5.2% of the dogs. The data on the distribution of the various worm species in the positive dogs indicate that T. canis eggs were by far the most common (50.9%). Necropsy data from 212 infected dogs indicate that 38.9% were infected with T. canis and 33.7% with T. leonina. The overall prevalence of worm infestation of 246 well-cared-for kennel dogs, based on worm egg counts by the McMaster technique, was 36.1%. Of 30 feline faecal samples examined by flotation, 83.3% were positive for parasites, including Toxocara cati (60%), Ancylostoma tubaeformae (36.6%), Taenia (Hydatigera) taeniaeformis (20%) and coccidia (30%). Toxocara cati was the most frequently found worm species at the necropsy of 25 cats (52%). Toxoplasma was not observed. PMID:2024431

  7. Cyclospora cayetanensis: This Emerging Protozoan Pathogen in Mexico

    PubMed Central

    Sánchez-Vega, José T.; Cabrera-Fuentes, Héctor A.; Romero-Olmedo, Addi J.; Ortiz-Frías, José L.; Sokolina, Flura; Barreto, Guillermo

    2014-01-01

    A Mexican airline pilot had clinical manifestations of illness after a five-day stay in Lima, Peru. Six months later in Mexico, he was given a diagnosis of infection with Cyclospora cayetanensis by using coproparasitoscopic serial tests. He was treated twice with nitazoxadine successfully. PMID:24379243

  8. Cyclospora cayetanensis: this emerging protozoan pathogen in Mexico.

    PubMed

    Sánchez-Vega, José T; Cabrera-Fuentes, Héctor A; Romero-Olmedo, Addi J; Ortiz-Frías, José L; Sokolina, Flura; Barreto, Guillermo

    2014-02-01

    A Mexican airline pilot had clinical manifestations of illness after a five-day stay in Lima, Peru. Six months later in Mexico, he was given a diagnosis of infection with Cyclospora cayetanensis by using coproparasitoscopic serial tests. He was treated twice with nitazoxadine successfully. PMID:24379243

  9. First Sequenced Mitochondrial Genome from the Phylum Acanthocephala( Leptorhynchoides thecatus ) and Its Phylogenetic Position Within Metazoa

    Microsoft Academic Search

    Michelle L. Steinauer; Brent B. Nickol; Richard Broughton; Guillermo Ortí

    2005-01-01

    The complete sequence of the mitochondrial genome of Leptorhynchoides thecatus (Acanthocephala) was determined, and a phylogenetic analysis was carried out to determine its placement within Metazoa. The genome is circular, 13,888 bp, and contains at least 36 of the 37 genes typically found in animal mitochondrial genomes. The genes for the large and small ribosomal RNA subunits are shorter than

  10. Draft Genome Sequence of Burkholderia gladioli Strain UCD-UG_CHAPALOTE (Phylum Proteobacteria)

    PubMed Central

    Ettinger, Cassandra L.; Shehata, Hanan R.; Johnston-Monje, David; Raizada, Manish N.

    2015-01-01

    Here, we present the draft genome of Burkholderia gladioli strain UCD-UG_CHAPALOTE. This strain is an endophyte isolated from surface sterilized seeds of an ancient Mexican landrace of corn, Chapalote. The genome contains 8,527,129 bp in 109 scaffolds. PMID:25614570

  11. A new isolate of Amoeboaphelidium protococcarum, and Amoeboaphelidium occidentale, a new species in phylum Aphelida (Opisthosporidia).

    PubMed

    Letcher, Peter M; Powell, Martha J; Lopez, Salvador; Lee, Philip A; McBride, Robert C

    2015-01-01

    Microalgae used in the production of biofuels represents an alternative to fossil fuels. One problem in the production of algae for biofuels is attacks by algal parasitoids that can cause population crashes when algae are cultivated in outdoor ponds (Greenwell et al. 2010). Integrated solutions are being sought to mitigate this problem, and an initial step is pest identification. We isolated an algal parasitoid from an open pond of Scenedesmus dimorphus used for biofuel production in New Mexico and examined its morphology, ultrastructure and molecular phylogeny. A phylogenetic analysis placed this organism in Aphelida as conspecific with Amoeboaphelidium protococcarum sensu Karpov et al. 2013. As a result we re-evaluated the taxonomy of Amoeboaphelidium protococcarum sensu Letcher et al. 2013 and here designate it as a new species, Amoeboaphelidium occidentale. PMID:25661716

  12. Bhargavaea indica sp. nov., a member of the phylum Firmicutes, isolated from Arabian Sea sediment.

    PubMed

    Verma, Pankaj; Seong, Chi Nam; Pandey, Prashant Kumar; Bhonde, Ramesh Ramchandra; Spröer, Cathrin; Rohde, Manfred; Shouche, Yogesh Shreepad

    2013-02-01

    A Gram-positive, aerobic, coccoid-rod shaped, non-motile, catalase- and oxidase-positive bacterium, designated strain KJW98(T), was isolated from the marine sediment of Karwar jetty, west coast of India. The strain was ?-haemolytic, non-endospore-forming and grew with 0-8.5% (w/v) NaCl, at 15-48°C and at pH 6.5-9.0, with optimum growth with 0.5% (w/v) NaCl, at 42°C and at pH 7.0-8.0. Phylogenetic analyses based on 16S rRNA and gyrB gene sequences showed that strain KJW98(T) forms a lineage within the genus Bhargavaea. The G+C content of the genomic DNA was 55 mol%. The DNA-DNA relatedness values of strain KJW98(T) with B. beijingensis DSM 19037(T), B. cecembensis LMG 24411(T) and B. ginsengi DSM 19038(T) were 43.2, 39 and 26.5%, respectively. The major fatty acids were anteiso-C15:0 (37.7%), iso-C15:0 (19.7%), anteiso-C17:0 (17.0%) and iso-C16:0 (11.1%). The predominant menaquinone was MK-8 and the cell-wall peptidoglycan was of A4? type with L-lysine as the diagnostic diamino acid. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The phenotypic, genotypic and DNA-DNA relatedness data indicate that strain KJW98(T) should be distinguished from the members of the genus Bhargavaea, for which the name Bhargavaea indica sp. nov. is proposed with the type strain KJW98(T) (=KCTC 13583(T) =LMG 25219(T)). PMID:23456710

  13. Diversity of the candidate phylum Poribacteria in the marine sponge Aplysina fulva

    PubMed Central

    Hardoim, C.C.P.; Cox, C.J.; Peixoto, R.S.; Rosado, A.S.; Costa, R.; van Elsas, J.D.

    2013-01-01

    Poribacterial clone libraries constructed for Aplysina fulva sponge specimens were analysed with respect to diversity and phylogeny. Results imply the coexistence of several, prevalently “intra-specific” poribacterial genotypes in a single sponge host, and suggest quantitative analysis as a desirable approach in studies of the diversity and distribution of poribacterial cohorts in marine sponges. PMID:24159324

  14. Reassessment of the phylogenetic position of conulariids (?Ediacaran?Triassic) within the subphylum medusozoa (phylum cnidaria)

    Microsoft Academic Search

    Heyo Van Iten; Juliana de Moraes Lerne; Marcello Guimarães Simões; Antonio Carlos Marques; Allen G. Collins

    2006-01-01

    Fossil taxa of uncertain phylogenetic affinities can play a crucial role in the analysis of character evolution within major extant groups. Marques & Collins (2004) concluded that conulariids (?Ediacaran?Triassic) are an extinct group of medusozoan cnidarians most closely related to Stauromedusae. However, only six of the 87 characters used by these authors can be observed in conulariid fossils. Rescoring the

  15. Evaluating the use of DNA Sequences for Species Identification in Medusozoans (Phylum Cnidaria)

    E-print Network

    Richardson, Rhea

    2012-04-01

    : Anthozoa and Medusozoa. Anthozoa are sessile polyps lacking a medusa stage in their life cycle. Medusozoa, which comprise almost 4000 species (Daly et al., 2007) can have a free- swimming medusa stage and a benthic polyp stage as part of their life...-cycle. However there are many modifications of this life cycle in different species of medusozoans (Brusca and Brusca, 2003). The medusozoans are also unique in that they have a linear mitochondrial genome (Ortman et al., 2010). Medusozoa is divided...

  16. A phylogenetic study of the Anthozoa (phylum Cnidaria) based on morphological and molecular characters

    Microsoft Academic Search

    J. Won; B. Rho; J. Song

    2001-01-01

    The phylogenetic relationships within the Anthozoa were re-evaluated based on 41 morphological characters and nuclear sequences of 18S ribosomal DNA (29 anthozoans as ingroups and 3 hydrozoans as outgroups). The parsimony trees derived from the morphological data did not coincide closely with the molecular data, and the presence of several polytomies at some nodes of the trees resulted in ambiguities

  17. Phylogenetic placement of the enigmatic parasite, Polypodium hydriforme, within the Phylum Cnidaria

    E-print Network

    Evans, Nathaniel Michael; Linder, Alberto; Raikova, Ekaterina V.; Collins, Allen G.; Cartwright, Paulyn

    2008-05-09

    in a large dataset that includes Polypodium and a comprehensive sampling of cnidarian taxa. Results: Analyses of a combined dataset of 18S and partial 28S sequences, and partial 28S alone, support the placement of Polypodium within Cnidaria. Removal...

  18. SCO-spondin is evolutionarily conserved in the central nervous system of the chordate phylum

    Microsoft Academic Search

    S Gobron; I Creveaux; R Meiniel; R Didier; B Dastugue; A Meiniel

    1999-01-01

    Bovine subcommissural organ-spondin was shown to be a brain-secreted glycoprotein specifically expressed in the subcommissural organ, an ependymal differentiation located in the roof of the Sylvian aqueduct. Also, subcommissural organ-spondin makes part of Reissner's fiber, a phylogenetically and ontogenetically conserved structure present in the central canal of the spinal cord of chordates. This secretion is a large multidomain protein probably

  19. Draft Genome Sequence of Curtobacterium flaccumfaciens Strain UCD-AKU (Phylum Actinobacteria).

    PubMed

    Flanagan, Jennifer C; Lang, Jenna M; Darling, Aaron E; Eisen, Jonathan A; Coil, David A

    2013-01-01

    Here we present the draft genome of an actinobacterium, Curtobacterium flaccumfaciens strain UCD-AKU, isolated from a residential carpet. The genome assembly contains 3,692,614 bp in 130 contigs. This is the first member of the Curtobacterium genus to be sequenced. PMID:23682147

  20. Phylum and Class-Specific PCR Primers for General Microbial Community Analysis

    Microsoft Academic Search

    Christopher B. Blackwood; Adam Oaks; Jeffrey S. Buyer

    2005-01-01

    Amplification of a particular DNA fragment from a mixture of organisms by PCR is a common first step in methods of examining microbial community structure. The use of group-specific primers in community DNA profiling applications can provide enhanced sensitivity and phylogenetic detail compared to domain-specific primers. Other uses for group-specific primers include quantitative PCR and library screening. The purpose of

  1. A molecular phylogeny of the flagellated fungi (Chytridiomycota) and description of a new phylum (Blastocladiomycota)

    E-print Network

    James, Timothy

    that reproduces through the production of motile spores (zoospores), typically propelled by a single, poster and desert soils, and acidic bogs as saprotrophs of refractory substrata including pollen, chitin, keratin

  2. DNA taxonomy of a neglected animal phylum: an unexpected diversity of tardigrades.

    PubMed Central

    Blaxter, Mark; Elsworth, Ben; Daub, Jennifer

    2004-01-01

    A molecular survey technique was used to investigate the diversity of terrestrial tardigrades from three sites within Scotland. Ribosomal small subunit sequence was used to classify specimens into molecular operational taxonomic units (MOTU). Most MOTU were identified to the generic level using digital voucher photography. Thirty-two MOTU were defined, a surprising abundance given that the documented British fauna is 68 species. Some tardigrade MOTU were shared between the two rural collection sites, but no MOTU were found in both urban and rural sites, which conflicts with models of ubiquity of meiofaunal taxa. The patterns of relatedness of MOTU were particularly intriguing, with some forming clades with low levels of divergence, suggestive of taxon flocks. Some morphological taxa contained well-separated MOTU, perhaps indicating the existence of cryptic taxa. DNA sequence-based MOTU proved to be a revealing method for meiofaunal diversity studies. PMID:15252980

  3. Fungal myocarditis and pericardial effusion secondary to Inonotus tropicalis (phylum Basidiomycota) in a dog.

    PubMed

    Ribas, Thibault; Pipe-Martin, Hannah; Kim, Kenneth S; Leissinger, Mary K; Bauer, Rudy W; Grasperge, Britton J; Grooters, Amy M; Sutton, Deanna A; Pariaut, Romain

    2015-06-01

    Fungal disease is a rare cause of pericardial effusion in dogs. This report describes the first case of fungal pericardial effusion and myocarditis secondary to the fungal organism Inonotus tropicalis. A 9-year-old female spayed French bulldog with a multi-year history of treatment with glucocorticoids for management of atopy was presented for exercise intolerance, ascites and weight loss. Physical examination and thoracic imaging revealed enlarged peripheral and cranial mediastinal lymph nodes, left ventricular thickening and cardiac tamponade secondary to pericardial effusion. Fine needle aspiration of the cranial mediastinal lymph node showed pyogranulomatous inflammation with short, thin and poorly septated hyphae. Culture of the aspirate yielded a fungal isolate identified as Inonotus tropicalis based on morphologic features and rRNA gene sequencing. Postmortem examination showed myocardial thickening with multifocal to coalescing, firm, white, ill-defined nodules. Histology confirmed the presence of disseminated fungal infection with extensive myocardial involvement. Inonotus tropicalis is an opportunistic poroid wood-decaying basidiomycete. Infection in this dog was likely the result of chronic immunosuppressive therapy. PMID:26003903

  4. Intra-phylum and inter-phyla associations among gastrointestinal parasites in two wild mammal species.

    PubMed

    Moreno, P G; Eberhardt, M A T; Lamattina, D; Previtali, M A; Beldomenico, P M

    2013-09-01

    A growing body of literature reveals that the interactions among the parasite community may be strong and significant for parasite dynamics. There may be inter-specific antagonistic interactions as a result of competition and cross-effective immune response, or synergistic interactions where infection by one parasite is facilitated by another one, either by an impoverishment of the host's defenses, parasite-induced selective immunosuppression, or trade-offs within the immune system. The nature of these interactions may depend on how related are the parasite species involved. Here we explored the presence of associations among gastrointestinal parasites (coccidia and helminths) in natural populations of two wild mammal species, the capybara (Hydrochoerus hydrochaeris) and the guanaco (Lama guanicoe). The associations explored were between the oocyst outputs of a selected Eimeria species and the other coccidia of that parasite community, and between Eimeria spp. and the predominant nematodes. The statistical analysis included adjustment for potential confounders or effect modifiers. In guanacos, the prevailing interactions were synergistic among the coccidia and between coccidia and nematodes (Nematodirus spp.). However, in capybaras, the interaction between nematodes (Viannaiidae) and Eimeria spp. depended on environmental and host factors. The relationship was positive in some circumstances (depending on season, year, sex, or animal size), but it appeared to become antagonistic under different scenarios. These antagonist interactions did not follow a particular seasonal pattern (they occurred in autumn, spring, and summer), but they were predominantly found in females (when they depended on sex) or in 2010 and 2011 (when they depended on the sampling year). These results suggest that the relationship between coccidia and nematodes in capybaras may be context dependent. We propose that the context-dependent immune investment documented in capybaras may be the cause of these varying interactions. PMID:23820605

  5. Genomics of Actinobacteria: Tracing the Evolutionary History of an Ancient Phylum

    PubMed Central

    Ventura, Marco; Canchaya, Carlos; Tauch, Andreas; Chandra, Govind; Fitzgerald, Gerald F.; Chater, Keith F.; van Sinderen, Douwe

    2007-01-01

    Summary: Actinobacteria constitute one of the largest phyla among Bacteria and represent gram-positive bacteria with a high G+C content in their DNA. This bacterial group includes microorganisms exhibiting a wide spectrum of morphologies, from coccoid to fragmenting hyphal forms, as well as possessing highly variable physiological and metabolic properties. Furthermore, Actinobacteria members have adopted different lifestyles, and can be pathogens (e.g., Corynebacterium, Mycobacterium, Nocardia, Tropheryma, and Propionibacterium), soil inhabitants (Streptomyces), plant commensals (Leifsonia), or gastrointestinal commensals (Bifidobacterium). The divergence of Actinobacteria from other bacteria is ancient, making it impossible to identify the phylogenetically closest bacterial group to Actinobacteria. Genome sequence analysis has revolutionized every aspect of bacterial biology by enhancing the understanding of the genetics, physiology, and evolutionary development of bacteria. Various actinobacterial genomes have been sequenced, revealing a wide genomic heterogeneity probably as a reflection of their biodiversity. This review provides an account of the recent explosion of actinobacterial genomics data and an attempt to place this in a biological and evolutionary context. PMID:17804669

  6. Invertebrate Paleontology Systematics Classification of Invertebrate Taxa for the Geology 250 Laboratory

    E-print Network

    Wilson, Mark A.

    5 Phylum Cnidaria 7 Phylum Brachiopoda 11 Phylum Bryozoa 17 Phylum Mollusca 19 Phylum Hyolitha 26 calcareous walls. #12;7 Phylum CNIDARIA: Ediacaran - Recent. Possess nematocysts ("stinging cells"). Class

  7. Haemogregarine specificity in two communities of Florida snakes, with descriptions of six new species of Hepatozoon (Apicomplexa: Hepatozoidae) and a possible species of Haemogregarina (Apicomplexa: Haemogregarinidae).

    PubMed

    Telford, S R; Wozniak, E J; Butler, J F

    2001-08-01

    Five species of snakes in Florida, from Palm Beach County in the south and Alachua County 450 km to the north, occur in similar habitat but have distinctive Hepatozoon species characteristic of each host species. In Palm Beach County, Diadophis punctatus is host to Hepatozoon punctatus n. sp., Thamnophis sauritus sackenii to Hepatozoon sauritus n. sp., and Nerodia fasciata pictiventris to Hepatozoon pictiventris n. sp. In Alachua County, N. fasciata pictiventris is parasitized by Hepatozoon fasciatae n. sp., Seminatrix p. pygaea by Hepatozoon seminatrici n. sp., and Thamnophis s. sirtalis by Hepatozoon sirtalis n. sp. Each Hepatozoon sp. has distinctive gamonts and sporogonic characters and, in the 4 species where known, meronts. Nerodia floridana is host to Haemogregarina floridana n. sp. in both localities, with generic identification tentative, based upon presence of erythrocytic meronts. The presence of sporocysts in the proboscis of 31% of Aedes aegypti infected by H. pictiventris is the first report of infective stages of a reptilian Hepatozoon species within the mouthparts of a dipteran vector. This study suggests that in Florida, at least, the diversity of the Hepatozoon community not only equals but probably exceeds the diversity of the snake communities present, and that host specificity in nature may be much greater than that postulated from previous studies. PMID:11534655

  8. Toxoplasma co-opts host gene expression by injection of a polymorphic kinase homologue.

    PubMed

    Saeij, J P J; Coller, S; Boyle, J P; Jerome, M E; White, M W; Boothroyd, J C

    2007-01-18

    Toxoplasma gondii, an obligate intracellular parasite of the phylum Apicomplexa, can cause severe disease in humans with an immature or suppressed immune system. The outcome of Toxoplasma infection is highly dependent on the strain type, as are many of its in vitro growth properties. Here we use genetic crosses between type II and III lines to show that strain-specific differences in the modulation of host cell transcription are mediated by a putative protein kinase, ROP16. Upon invasion by the parasite, this polymorphic protein is released from the apical organelles known as rhoptries and injected into the host cell, where it ultimately affects the activation of signal transducer and activator of transcription (STAT) signalling pathways and consequent downstream effects on a key host cytokine, interleukin (IL)-12. Our findings provide a new mechanism for how an intracellular eukaryotic pathogen can interact with its host and reveal important differences in how different Toxoplasma lineages have evolved to exploit this interaction. PMID:17183270

  9. Molecular phylogeny of Besnoitia and the genetic relationships among Besnoitia of cattle, wildebeest and goats.

    PubMed

    Ellis, J T; Holmdahl, O J; Ryce, C; Njenga, J M; Harper, P A; Morrison, D A

    2000-12-01

    Knowledge on parasites of the genus Besnoitia is sparse, which are classified in the subfamily Toxoplasmatinae of the phylum Apicomplexa. This arrangement hypotheses that Besnoitia represents the sister group to species such as Toxoplasma gondii and Hammondia hammondi. In order to test this hypothesis, phylogenetic analyses of 18S ribosomal DNA (rDNA) from Besnoitia, Hammondia, Isospora, Frenkelia, Eimeria, Neospora, Sarcocystis and Toxoplasma were performed. The 18S rDNA of Besnoitia besnoiti, Besnoitia jellisoni and Eimeria alabamensis were amplified by PCR and sequenced. Phylogenetic analyses by parsimony and maximum-likelihood methods showed Besnoitia to be reproducibly the sister group to a clade containing Hammondia, Neospora and Toxoplasma. Furthermore, Besnoitia of cattle, wildebeest and goats had identical ITS1 rDNA sequences, which questions the use of the taxon Besnoitia caprae to describe the Besnoitia found in goats. PMID:11212893

  10. Protein export into malaria parasite-infected erythrocytes: mechanisms and functional consequences.

    PubMed

    Spillman, Natalie J; Beck, Josh R; Goldberg, Daniel E

    2015-06-01

    Phylum Apicomplexa comprises a large group of obligate intracellular parasites of high medical and veterinary importance. These organisms succeed intracellularly by effecting remarkable changes in a broad range of diverse host cells. The transformation of the host erythrocyte is particularly striking in the case of the malaria parasite Plasmodium falciparum. P. falciparum exports hundreds of proteins that mediate a complex cellular renovation marked by changes in the permeability, rigidity, and cytoadherence properties of the host erythrocyte. The past decade has seen enormous progress in understanding the identity and function of these exported effectors, as well as the mechanisms by which they are trafficked into the host cell. Here we review these advances, place them in the context of host manipulation by related apicomplexans, and propose key directions for future research. PMID:25621510

  11. Host-parasite interactions: an intimate epigenetic relationship.

    PubMed

    Cheeseman, Kevin; Weitzman, Jonathan B

    2015-08-01

    The epigenetics of host-pathogen interactions is emerging as an interesting angle from which to study how parasites have evolved sophisticated strategies to manipulate host gene transcription and protein expression. In this review, we discuss the application of an operational framework to investigate the host cell signalling pathways that are induced by intracellular parasites and the epigenomic consequences in the host nucleus. To illustrate this conceptual approach, we have focused on examples from two eukaryotic intracellular parasites of the apicomplexa phylum: Theileria and Toxoplasma. We review recent findings on intracellular parasitism strategies for hijacking host nuclear functions and discuss how we might think of the parasite and its proteome as an intracellular epigenator. PMID:26096716

  12. Combined Amplicon Pyrosequencing Assays Reveal Presence of the Apicomplexan “type-N” (cf. Gemmocystis cylindrus) and Chromera velia on the Great Barrier Reef, Australia

    PubMed Central

    Šlapeta, Jan; Linares, Marjorie C.

    2013-01-01

    Background The coral is predominantly composed of the metabolically dependent coral host and the photosynthetic dinoflagellate Symbiodinium sp. The system as a whole interacts with symbiotic eukaryotes, bacteria and viruses. Gemmocystiscylindrus (cf. “type-N” symbiont) belonging to the obligatory parasitic phylum Apicomplexa (Alveolata) is ubiquitous in the Caribbean coral, but its presence in the Great Barrier Reef coral has yet to be documented. Approaches allowing identification of the healthy community from the pathogenic or saprobic organisms are needed for sustainable coral reef monitoring. Methods & Principal Findings We investigated the diversity of eukaryotes associated with a common reef-building corals from the southern Great Barrier Reef. We used three tag encoded 454 amplicon pyrosequencing assays targeting eukaryote small-subunit rRNA gene to demonstrate the presence of the apicomplexan type-N and a photosynthetic sister species to Apicomplexa - Chromeravelia. Amplicon pyrosequencing revealed presence of the small-subunit rRNA genes of known eukaryotic pathogens (Cryptosporidium and Cryptococcus). We therefore conducted bacterial tag encoded amplicon pyrosequencing assay for small-subunit rRNA gene to support effluent exposure of the coral. Bacteria of faecal origin (Enterobacteriales) formed 41% of total sequences in contrast to 0-2% of the coral-associated bacterial communities with and without C. velia, respectively. Significance This is the first time apicomplexan type-N has been detected in the Great Barrier Reef. Eukaryote tag encoded amplicon pyrosequencing assays demonstrate presence of apicomplexan type-N and C. Velia in total coral DNA. The data highlight the need for combined approaches for eukaryotic diversity studies coupled with bacterial community assessment to achieve a more realistic goals of defining the holobiont community and assessing coral disease. With increasing evidence of Apicomplexa in coral reef environments, it is important not only to understand the evolution of these organisms but also identify their potential as pathogens. PMID:24098768

  13. Novel type of linear mitochondrial genomes with dual flip-flop inversion system in apicomplexan parasites, Babesia microti and Babesia rodhaini

    PubMed Central

    2012-01-01

    Background Mitochondrial (mt) genomes vary considerably in size, structure and gene content. The mt genomes of the phylum Apicomplexa, which includes important human pathogens such as the malaria parasite Plasmodium, also show marked diversity of structure. Plasmodium has a concatenated linear mt genome of the smallest size (6-kb); Babesia and Theileria have a linear monomeric mt genome (6.5-kb to 8.2-kb) with terminal inverted repeats; Eimeria, which is distantly related to Plasmodium and Babesia/Theileria, possesses a mt genome (6.2-kb) with a concatemeric form similar to that of Plasmodium; Cryptosporidium, the earliest branching lineage within the phylum Apicomplexa, has no mt genome. We are interested in the evolutionary origin of linear mt genomes of Babesia/Theileria, and have investigated mt genome structures in members of archaeopiroplasmid, a lineage branched off earlier from Babesia/Theileria. Results The complete mt genomes of archaeopiroplasmid parasites, Babesia microti and Babesia rodhaini, were sequenced. The mt genomes of B. microti (11.1-kb) and B. rodhaini (6.9-kb) possess two pairs of unique inverted repeats, IR-A and IR-B. Flip-flop inversions between two IR-As and between two IR-Bs appear to generate four distinct genome structures that are present at an equi-molar ratio. An individual parasite contained multiple mt genome structures, with 20 copies and 2 – 3 copies per haploid nuclear genome in B. microti and B. rodhaini, respectively. Conclusion We found a novel linear monomeric mt genome structure of B. microti and B. rhodhaini equipped with dual flip-flop inversion system, by which four distinct genome structures are readily generated. To our knowledge, this study is the first to report the presence of two pairs of distinct IR sequences within a monomeric linear mt genome. The present finding provides insight into further understanding of evolution of mt genome structure. PMID:23151128

  14. Survey for natural Neospora caninum infection in wild and captive birds.

    PubMed

    Mineo, Tiago W P; Carrasco, Adriano O T; Raso, Tânia F; Werther, Karin; Pinto, Aramis A; Machado, Rosangela Z

    2011-12-15

    Neospora caninum is a protozoan parasite that presents worldwide distribution and is mainly implicated as responsible for bovine abortion. Although the presence of birds in cattle-raising properties is positively correlated to higher infection rates, very little has been described about the role of these animals in the parasite's life cycle. In that sense, this work aimed to investigate the serological and histological positivity of different avian species sampled in its natural habitat or in captivity. No serological positivity was observed in the 294 tested serum samples. On the other hand, Apicomplexa-like cysts found in muscular tissues of two Psittaciformes were immunostained with N. caninum antisera. These findings indicate that N. caninum may infect a wider range of hosts than described to date, and that further studies should be performed in order to determine the presence of the infection in different avian species. PMID:21680099

  15. Invasion factors of apicomplexan parasites: essential or redundant?

    PubMed

    Meissner, Markus; Ferguson, David J P; Frischknecht, Freddy

    2013-08-01

    Apicomplexa are obligate intracellular parasites that cause several human and veterinary diseases worldwide. In contrast to most intracellular pathogens these protozoans are believed to invade a rather passive host cell in a process, that is, tightly linked to the ability of the parasites to move by gliding motility. Indeed specific inhibitors against components of the gliding machinery and the analysis of knockdown mutants demonstrate a linkage of gliding motility and invasion. Intriguingly, new data show that it is possible to block gliding motility, while host cell invasion still occurs. This suggests that either the current models established for host cell invasion need to be critically revised or that alternative, motor independent mechanisms are in place including a more active role of the host cell that can complement a missing actin-myosin-system. Here we discuss some of the discrepancies that need to be addressed for a better understanding of invasion. PMID:23727286

  16. Species of Eimeria (Apicomplexa: Eimeriidae) from bats (Chiroptera: Vespertilionidae) in central Wyoming.

    PubMed

    Seville, Robert S; Gruver, Jeffrey

    2004-04-01

    Feces from 60 bats representing 5 species and 4 genera collected in central Wyoming in 2001 were examined for the presence of coccidia. Two species of Eimeria were identified in 4 bats representing 2 species of Myotis. All infected animals harbored a single species; there was no multispecies infection. Eimeria catronensis was recovered from 3 little brown bats (Myotis lucifugus), and Eimeria californicensis was identified from a single long-legged myotis (Myotis volans). Both represent new geographic records and the second a new host record. Eimeria catronensis-like oocysts were recovered from a single silver-haired bat (Lasionycteris noctivagans). Descriptions and taxonomic summaries for the eimerian species are presented in this study. PMID:15165058

  17. Complete mitochondrial genome sequences from five Eimeria species (Apicomplexa; Coccidia; Eimeriidae) infecting domestic turkeys

    PubMed Central

    2014-01-01

    Background Clinical and subclinical coccidiosis is cosmopolitan and inflicts significant losses to the poultry industry globally. Seven named Eimeria species are responsible for coccidiosis in turkeys: Eimeria dispersa; Eimeria meleagrimitis; Eimeria gallopavonis; Eimeria meleagridis; Eimeria adenoeides; Eimeria innocua; and, Eimeria subrotunda. Although attempts have been made to characterize these parasites molecularly at the nuclear 18S rDNA and ITS loci, the maternally-derived and mitotically replicating mitochondrial genome may be more suited for species level molecular work; however, only limited sequence data are available for Eimeria spp. infecting turkeys. The purpose of this study was to sequence and annotate the complete mitochondrial genomes from 5 Eimeria species that commonly infect the domestic turkey (Meleagris gallopavo). Methods Six single-oocyst derived cultures of five Eimeria species infecting turkeys were PCR-amplified and sequenced completely prior to detailed annotation. Resulting sequences were aligned and used in phylogenetic analyses (BI, ML, and MP) that included complete mitochondrial genomes from 16 Eimeria species or concatenated CDS sequences from each genome. Results Complete mitochondrial genome sequences were obtained for Eimeria adenoeides Guelph, 6211 bp; Eimeria dispersa Briston, 6238 bp; Eimeria meleagridis USAR97-01, 6212 bp; Eimeria meleagrimitis USMN08-01, 6165 bp; Eimeria gallopavonis Weybridge, 6215 bp; and Eimeria gallopavonis USKS06-01, 6215 bp). The order, orientation and CDS lengths of the three protein coding genes (COI, COIII and CytB) as well as rDNA fragments encoding ribosomal large and small subunit rRNA were conserved among all sequences. Pairwise sequence identities between species ranged from 88.1% to 98.2%; sequence variability was concentrated within CDS or between rDNA fragments (where indels were common). No phylogenetic reconstruction supported monophyly of Eimeria species infecting turkeys; Eimeria dispersa may have arisen via host switching from another avian host. Phylogenetic analyses suggest E. necatrix and E. tenella are related distantly to other Eimeria of chickens. Conclusions Mitochondrial genomes of Eimeria species sequenced to date are highly conserved with regard to gene content and structure. Nonetheless, complete mitochondrial genome sequences and, particularly the three CDS, possess sufficient sequence variability for differentiating Eimeria species of poultry. The mitochondrial genome sequences are highly suited for molecular diagnostics and phylogenetics of coccidia and, potentially, genetic markers for molecular epidemiology. PMID:25034633

  18. High prevalence of Hepatozoon spp. (Apicomplexa, Hepatozoidae) infection in water pythons (Liasis fuscus) from tropical Australia.

    PubMed

    Ujvari, Beata; Madsen, Thomas; Olsson, Mats

    2004-06-01

    Molecular methods were used to identify blood parasites frequently observed in blood smears of water pythons (Liasis fuscus) captured in our study area in the Northern Territory of Australia. A nested polymerase chain reaction (PCR) using primers amplifying the 18s ribosomal RNA (rRNA) nuclear gene resulted in a short PCR product (180 bp) matching this region in the genus Hepatozoon. However, because of the short sequence obtained. 2 new primers were designed based on 18s rRNA sequences of 3 Hepatozoon taxa available in GenBank. Using these primers, approximately 600 bp of the parasite's 18s rRNA gene was amplified successfully and sequenced from 2 water python samples. The new primers were used to investigate the prevalence of blood parasites in 100 pythons. In 25 of these samples we did not observe any blood parasites when examining stained slides. All the samples revealed a 600-bp PCR product, demonstrating that pythons in which we did not visually observe any parasites were infected by Hepatozoon spp. We also analyzed the nucleotide sequences of blood parasites in 4 other reptile taxa commonly encountered in our study area. The sequences obtained from water pythons and from 1 of these taxa were identical, suggesting that the parasite is capable of infecting hosts at different taxonomic levels. PMID:15270125

  19. Larval Gulf Coast ticks ( Amblyomma maculatum) [Acari: Ixodidae] as host for Hepatozoon americanum [Apicomplexa: Adeleorina

    Microsoft Academic Search

    S. A. Ewing; J. G. DuBois; J. S. Mathew; R. J. Panciera

    2002-01-01

    Laboratory-reared larval Gulf Coast ticks (GCTs) (Amblyomma maculatum) were exposed experimentally and found to acquire Hepatozoon americanum infection while feeding on parasitemic dogs. These ticks supported gamogonic and sporogonic development of the apicomplexan, and oocysts from newly molted nymphs were infectious for a dog. Other nymphs from this cohort that were allowed to feed on a blood-parasite naive sheep molted

  20. The fine structure of the gamont of Pterospora floridiensis (Apicomplexa: Eugregarinida).

    PubMed

    Landers, Stephen C

    2002-01-01

    Transmission electron microscopy of the gamont stage of Pterospora floridiensis has revealed a number of features. The gamont's surface varies from smooth to crenulate, with numerous pockets and folds. The pellicle is composed of an outer membrane, a middle lucent region, and an inner dense layer comprised of two tightly appressed membranes. Short ridges on the pellicle are 200-300+ nm long, 75-100 nm wide, and have a height of approximately 50 nm. The thickness of the pellicle is 100 nm when measured from the inner membrane to the top of a ridge. The ridges are formed by the plasma membrane and an underlying structure that is circular in cross-section. The surface folds and the pellicular ridges are distributed over the soma and the cell's unusual branching arms, though both are reduced near the junction between two gamonts in syzygy, and are absent at the central area of the junctional site. The cell has numerous active Golgi complexes associated with vesicles, as well as scattered dense mitochondria, lipid droplets, and paraglycogen granules. The nucleus has a large (13 microm) endosome, eccentrically located, and peripheral chromatin along the inner nuclear membrane. PMID:12120987

  1. Monocystis metaphirae sp. nov. (Protista: Apicomplexa: Monocystidae) from the earthworm Metaphire houlleti (Perrier).

    PubMed

    Bandyopadhyay, Probir K; Mallik, Partha; Göçmen, Bayram; Mitra, Amlan Kumar

    2006-01-01

    Biodiversity studies in search of endoparasitic acephaline gregarines revealed a new species of the genus Monocystis Stein, 1848 in the seminal vesicles of the earthworm Metaphire houlleti (Perrier) residing in alluvial soil of the district of North 24 Parganas. The new species is characterized by having bean-shaped gamonts measuring 94.0-151.0 (119.0+/-16.0) microm x 53.0-81.0(66.0+/-8.0) microm. The anterior end of the gamont is always wider than the posterior end. The mucron is always present at the wider end. The occurrence of syzygy (end to end, cauda-frontal) is a very rare feature which has been observed in the life cycle of the new species. The gametocyst is ovoid consisting of two unequal gamonts, measuring 85.0-102.0 microm (93.0+/-6.0). Oocysts are navicular in shape, measuring 6.5-11.0 (9.0+/-1.1) microm x 4.0-7.5 (5.5+/-1.9) microm. PMID:17106857

  2. Gametogenesis and sporogony of Hepatozoon mocassini (Apicomplexa: Adeleina: Hepatozoidae) in an experimental mosquito host, Aedes aegypti.

    PubMed

    Lowichik, A; Lanners, H N; Lowrie, R C; Meiners, N E

    1993-01-01

    The sexual life cycle of the hemogregarine Hepatozoon mocassini was studied in Aedes aegypti, an experimental mosquito host, using transmission electron microscopy. Gamonts were observed leaving the host snake erythrocyte as early as 30 min after mosquitoes ingested infected blood, and some gamonts had penetrated the gut epithelial cells by this time. Six hours post-feeding, gamonts were identified within cells of the abdominal fat body. Twenty-four hours post-feeding, gamonts were often entrapped within the peritrophic membrane, but were no longer observed within the gut wall. Parasites pairing up in syzygy and undergoing sexual differentiation were observed within fat cells at this time, and by 48 hours post-feeding, well-developed macro- and microgametocytes as well as microgametes were discernible. Developing zygotes observed 3 days post-feeding were enclosed within a parasitophorous vacuole. By day 6, multinucleate oocysts with crystalloid bodies in the cytoplasm were seen. Sporozoites developing within sporocysts appeared by day 12. Seventeen days post-feeding, mature oocysts with sporocysts containing approximately 16 sporozoites were observed upon dissection of mosquitoes. Large crystalloid bodies no longer bound by rough endoplasmic reticulum were located anterior and posterior to the sporozoite nucleus. Free sporozoites were not observed. PMID:8508167

  3. Life cycle, host restriction and longevity of Babesiosoma mariae HOARE, 1930 (Apicomplexa: Dactylosomatidae).

    PubMed

    Negm-Eldin, M M

    1998-10-01

    Morphometric and morphological observations on B. mariae in an experimentally infected fish (using the leech vector Batracobdeloides tricarinata for the first time) revealed that three successive types of merogonic cycles occurred within the fish erythrocytes. The third cycle produced merozoites destined to become gamonts. The gamonts were somewhat larger than merogonic stages and comprised the majority of the parasitic stages during parasitaemia for up to 7 months. In the leech crop gamonts released from the fish blood became associated in syzygy and fused. The formed zygote underwent sporogony within the gut tissues and up to 8 sporozoites budded simultaneously from the periphery of an irregularly shaped oocyst. The sporozoites underwent merogony typical as that of erythrocytic merogony mainly in the salivary tissues. The merozoites either initiated a further cycle of merogony or moved towards the proboscis. The babesiosomes survived in the leech over a period of 9 months involving 7 meals after the initial meal provided the fasting period did not exceed 60-90 days. Survival was attributed to residual stages in the salivary glands. Cross transmission experiments between fishes via B. tricarinata revealed that the fish babesiosomes were not host specific. Previously described African fresh water fish dactylosomatids were indistinguishable from each other and on the basis of the current results, they are regarded as a single species Babesiosoma mariae. PMID:9818523

  4. Ultrastructural development of the sarcocyst of Sarcocystis rauschorum (Apicomplexa: Sarcocystidae) in the varying lemming Dicrostonyx richardsoni.

    PubMed

    Friesen, D L; Cawthorn, R J; Speer, C A; Brooks, R J

    1989-06-01

    The development of the sarcocyst of Sarcocystis rauschorum in its intermediate host was studied. Lemmings were orally administered sporocysts of S. rauschorum obtained from snowy owls (Nyctea scandiaca). Beginning at 9 days postinoculation (DPI) and at various intervals to 84 DPI, skeletal muscle tissue taken from the infected lemmings was examined by electron microscopy. At 9 DPI the sarcocysts contained few metrocytes and the cyst wall was flat. The metrocytes underwent endodyogeny, and within a few days the cyst wall of the rapidly growing sarcocyst developed numerous tubulovesicular invaginations into the electron-dense layer, and the wall had a few irregular infoldings. By 21 DPI, banana-shaped bradyzoites appeared, and by 84 DPI the mature cysts were filled with bradyzoites in groups subdivided by septa and by deep infoldings of the cyst wall. The fine structure of the wall remained simple throughout maturation, with no conspicuous invagination or protrusion. The sarcocyst produced in response to S. rauschorum is unlike those from many species of Sarcocystis, which have complex walls that change markedly as the sarcocysts mature; however, its simple appearance is similar to other species that have rodents as intermediate hosts and raptorial birds as definitive hosts. PMID:2498495

  5. Coccidia (Apicomplexa: Eimeriidae) of the lowland European bison Bison bonasus bonasus (L.).

    PubMed

    Pyziel, Anna M; Jó?wikowski, Micha?; Demiaszkiewicz, Aleksander W

    2014-05-28

    Coprological studies conducted between 2007 and 2011 in free-roaming and captive European bison Bison bonasus (Linnaeus, 1758) from Poland revealed 11 species of Eimeria infecting the host, i.e., Eimeria alabamensis, Eimeria auburnensis, Eimeria bovis, Eimeria brasiliensis, Eimeria bukidnonensis, Eimeria canadensis, Eimeria cylindrica, Eimeria ellipsoidalis, Eimeria pellita, Eimeria subspherica, and Eimeria zuernii. The typical host for all isolated species is cattle. The most prevalent species was E. bovis (29.7%), while E. brasiliensis was the rarest (0.5%). Five of the species (E. bovis, E. bukidnonensis, E. canadensis, E. ellipsoidalis, E. zuernii) have been observed previously in bison by other authors, 3 species were noticed by us in bison previously (E. alabamensis, E. cylindrica, E. pellita), while for 3 species (E. auburnensis, E. brasiliensis, and E. subspherica) these are new host and locality records. Oocysts of two species (E. brasiliensis, E. bukidnonensis) were noted only in the feces of bison kept in captivity. Moreover, the prevalence of positive samples was higher in the group of captive animals (55.4%) in comparison with the free-roaming herds (29.5%); although, oocysts per gram (OPG), counted with the conventional McMaster technique, was comparable in both groups, reaching maximally 6550 and 6400 in free-roaming and captive individuals, respectively. Overall, 142 fecal samples from 424 samples examined were positive for Eimeria (prevalence=33.5%). Age-related analysis revealed a higher percentage of Eimeria spp. positive samples and higher OPG values in bison under 1 year old as compared to older individuals (93.3% and 50-4050; 37.3% and 50-550, respectively). Additionally, greater eimerian species diversity was present among calves in comparison with older bison. In most cases single-species infections were observed (59.8%) with a predominance of E. bovis (85.9%). Multiple-species infections consisted of 2-7 species, usually including E. bovis. The observation was made that E. bovis infection appears conducive to the host acquiring more eimerian species. No symptoms of clinical coccidiosis occurred during the study. PMID:24702772

  6. Caryospora bigenetica (Apicomplexa: Eimeriidae) in South America: new hosts and distribution records.

    PubMed

    Viana, Lúcio André; Mecchi, Kamilla Costa; Nascimento, Leonardo França do; Herrera, Heitor Miraglia; Santa-Rita, Paula Helena; Miglionico, Marcos Tobias de Santana; Esteves, Rhaiza Gama; Gimenez, Anibal Rafael Melgarejo; Paiva, Fernando

    2015-01-01

    The coccidian Caryospora bigenetica was first described in the snake Crotalus horridus (Viperidae) from United States of America. This study represents the first record of the occurrence of C. bigenetica in snakes in South America. Feces were sampled between November 2013 and May 2014 from 256 wild snakes maintained in scientific breeding facilities in the states of Mato Grosso do Sul (MS; n = 214) and Rio de Janeiro (RJ; n = 42), Brazil. Caryospora bigenetica was found in 14 (5.6%) snakes, all belonging to the family Viperidae. Ten Bothrops moojeni and two Crotalus durissus from MS were infected. The coccidian was also found in one C. durissus and in one Bothrops jararacussu from the state of RJ. The oocysts were spherical with a double wall, the exterior lightly mammillated, striations apparent in transverse view, 13.0 µm (12 - 14); polar granule fixed in the internal wall. Sporocysts oval or pyriform, 10.0 × 8.0 µm (9 - 11 × 8 - 9); Stieda body discoid; sub-Stieda body present; sporocyst residuum present, formed by a group of spheroid bodies between sporozoites. This study increases the number of viperid hosts of C. bigenetica and expands the geographical distribution to South America. PMID:25909262

  7. Cryptosporidium scrofarum n. sp. (Apicomplexa: Cryptosporidiidae) in domestic pigs (Sus scrofa)

    PubMed Central

    Kvá?, Martin; Kest?ánová, Michaela; Pinková, Martina; Kv?to?ová, Dana; Kalinová, Jana; Wagnerová, Pavla; Kotková, Michaela; Vítovec, Ji?í; Ditrich, Oleg; McEvoy, John; Stenger, Brianna; Sak, Bohumil

    2012-01-01

    We describe the morphological, biological, and molecular characteristics of Cryptosporidium pig genotype II and propose the species name Cryptosporidium scrofarum n. sp. to reflect its prevalence in adult pigs worldwide. Oocysts of C. scrofarum are morphologically indistinguishable from C. parvum, measuring 4.81–5.96 µm (mean = 5.16) × 4.23–5.29 µm (mean = 4.83) with a length to width ratio of 1.07 ± 0.06 (n = 400). Oocysts of C. scrofarum obtained from a naturally infected pig were infectious for 8-week-old pigs but not 4-week-old pigs. The prepatent period in 8-week-old Cryptosporidium-naive pigs was 4–6 days and the patent period was longer than 30 days. The infection intensity of C. scrofarum in pigs was generally low, in the range 250-4000 oocysts per gram of faeces. Infected pigs showed no clinical signs of cryptosporidiosis and no pathology was detected. Cryptosporidium scrofarum was not infectious for adult SCID mice, adult BALB c mice, Mongolian gerbils (Meriones unguiculatus), southern multimammate mice (Mastomys coucha), yellow-necked mice (Apodemus flavicollis), or guinea pigs (Cavia porcellus). Phylogenetic analyses based on Small subunit rRNA, actin, and heat shock protein 70 gene sequences revealed that C. scrofarum is genetically distinct from all known Cryptosporidium species. PMID:23021264

  8. First report of Hepatozoon (Apicomplexa: Adeleorina) in caecilians, with description of a new species.

    PubMed

    Harris, D James; Damas-Moreira, Isabel; Maia, João P M C; Perera, Ana

    2014-02-01

    Hepatozoon spp. are identified for the first time in the amphibian order Gymnophiona, or caecilians, from the Seychelles island of Silhouette. Estimate of relationships derived from partial 18S rRNA gene sequences indicate these are not related to Hepatozoon spp. from frogs or to other Hepatozoon spp. from reptiles in the Seychelles. Assessment of mature gamonts from blood smears indicate that these can be recognized as a new species, Hepatozoon seychellensis n. sp. PMID:23971488

  9. Occurrence of Leucocytozoon and Haemoproteus (Apicomplexa, Haemosporina) in Falconiformes and Strigiformes of Italy.

    PubMed

    Sacchi, L; Prigioni, C

    1984-01-01

    Blood smears from Falconiformes (91 birds of 10 species) and Strigiformes (23 birds of 5 species) captured in Italy, were examined for haematozoa. Leucocytozoon were found in Falco tinnuculus, Buteo buteo, Circus cyaneus, Circus pygargus, Accipiter nisus from Falconiformes and in Strix aluco, from Strigiformes. Haemoproteus were found in Falco tinnuculus and Strix aluco; this latter species harbored mixed infections Leucocytozoon-Haemoproteus. Prevalences were 20.80% in Falconiformes and 21.74% in Strigiformes. PMID:6431891

  10. Enteric Coccidia (Apicomplexa) in the Small Intestine of the Northern Spotted Owl (Strix occidentalis caurina)

    Microsoft Academic Search

    E. P. Hoberg; R. J. Cawthorn; R. Hedstrom

    1993-01-01

    Sporulated oocysts (mean dimen- sions = 13.0 x 10.8 ?tm) and sporocysts (11.3 x 5.5 Mm) of a coccidian resembling Frenkelia sp. or Sarcocystis sp. were present in the lamina propria of the small intestine of a naturally- infected northern spotted owl (Strix occiden- talis caurina) collected near Medford, Oregon (USA). Dimensions of these oocysts and sporo- cysts appear to

  11. CALYPTOSPORA FUNDULI (APICOMPLEXA, CALYPTOSPORIDAE IN THE LIVER OF THE GULF TOADFISH, OPSANUS BETA

    EPA Science Inventory

    Authors report the occurrence of what appears to be C. funduli nfecting the liver of a single specimen of gulf toadfish, opsanus eta, from a total of 54 toadfish livers examined histologically. oadfish were captured by trawling from aters of the Mississippi ound near ocean Spring...

  12. CRYPTOSPORIDIUM ANDERSONI N. SP. (APICOMPLEXA: CRYPTOSPORIDIIDAE) FROM CATTLE, BOS TAURUS. (R825148)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  13. CRYPTOSPORIDIUM HOMINIS N. SP (APICOMPLEXA : CRYPTOSPORIDIIDAE) FROM HOMO SAPIENS. (R826138)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. The fine structure of the developing oocyst of Pterospora floridiensis (Apicomplexa, Urosporidae).

    PubMed

    Landers, Stephen C

    2010-01-01

    Developing oocysts of the gregarine Pterospora floridiensis Landers 2001 were examined by transmission electron microscopy. Each oocyst had an outer capsule and an inner capsule that contained 8 sporozoites. In early stages of development the inner capsular wall was separated from the developing sporozoites and residual mass, and was not appressed to the sporozoites. Early stage sporozoites were connected to a residual mass and were filled with endoplasmic reticulum, golgi and numerous developing secretory vesicles. In late stages of oocyst and sporozoite development, the inner capsular wall was closely appressed to the sporozoite surface. The inner capsular wall was approximately 60-100 nm thick and the outer capsular wall was approximately 160-320 nm thick. There were no extensions on the outer wall for which the genus was named. Late stage sporozoites had no residual mass connection, were more electron dense, and contained three distinct types of dense secretory structures: 1) small oval/spherical dense vesicles, 2) large (350-400 nm) vesicles near the anterior end, and 3) elongated dense tubular bodies that converged at the apex. Few ultrastructural reports exist of developing gregarine oocysts and sporozoites, and as more studies are completed these morphological characteristics may be important in interpreting molecular phylogenetic analyses. PMID:20006476

  15. Molecular phylogeny and surface morphology of marine aseptate gregarines (Apicomplexa): Selenidium spp. and Lecudina spp.

    PubMed

    Leander, B S; Harper, J T; Keeling, P J

    2003-12-01

    Many aseptate gregarines from marine invertebrate hosts are thought to have retained several plesiomorphic characteristics and are instrumental in understanding the early evolution of intracellular parasitism in apicomplexans and the phylogenetic position of cryptosporidians. We sequenced the small-subunit (SSU) ribosomal RNA genes from 2 archigregarines, Selenidium terebellae and Selenidium vivax, and 2 morphotypes of the marine eugregarine Lecudina polymorpha. We also used scanning electron microscopy to investigate the surface morphology of trophozoites from Lecudina tuzetae, Monocystis agilis, the 2 species of Selenidium, and the 2 morphotypes of L. polymorpha. The SSU ribosomal DNA sequences from S. vivax and L. polymorpha had long branch lengths characteristic of other gregarine sequences. However, the sequence from S. terebellae was not exceptionally divergent and consistently emerged as 1 of the earliest 'true' gregarines in phylogenetic analyses. Statistical support for the sister relationship between Cryptosporidium spp. and gregarines was significantly bolstered in analyses including the sequence from S. terebellae but excluding the longest branches in the alignment. Eugregarines formed a monophyletic group with the neogregarine Ophryocystis, suggesting that trophozoites with elaborate cortex folds and gliding motility evolved only once. The trophozoites from the 2 species of Selenidium shared novel transverse striations but differed from one another in overall cell morphologies and writhing behavior. PMID:14740910

  16. The development of Psychodiella sergenti (Apicomplexa: Eugregarinorida) in Phlebotomus sergenti (Diptera: Psychodidae)

    PubMed Central

    LANTOVA, LUCIE; VOLF, PETR

    2012-01-01

    SUMMARY Psychodiella sergenti is a recently described specific pathogen of the sand fly Phlebotomus sergenti, the main vector of Leishmania tropica. The aim of this study was to examine the life cycle of Ps. sergenti in various developmental stages of the sand fly host. The microscopical methods used include scanning electron microscopy, transmission electron microscopy and light microscopy of native preparations and histological sections stained with periodic acid-Schiff reaction. Psychodiella sergenti oocysts were observed on the chorion of sand fly eggs. In 1st instar larvae, sporozoites were located in the ectoperitrophic space of the intestine. No intracellular stages were found. In 4th instar larvae, Ps. sergenti was mostly located in the ectoperitrophic space of the intestine of the larvae before defecation and in the intestinal lumen of the larvae after defecation. In adults, the parasite was recorded in the body cavity, where the sexual development was triggered by a bloodmeal intake. Psychodiella sergenti has several unique features. It develops sexually exclusively in sand fly females that took a bloodmeal, and its sporozoites bear a distinctive conoid (about 700 nm long), which is more than 4 times longer than conoids of the mosquito gregarines. PMID:22313575

  17. Effects of Psychodiella sergenti (Apicomplexa, Eugregarinorida) on its natural host Phlebotomus sergenti (Diptera, Psychodidae).

    PubMed

    Lantova, Lucie; Svobodova, Milena; Volf, Petr

    2011-09-01

    Phlebotomine sand flies (Diptera, Psychodidae) are important vectors of human pathogens. Moreover, they possess monoxenous parasites, including gregarines of the genus Psychodiella Votypka, Lantova, and Volf, which can negatively affect laboratory-reared colonies, and have been considered as potential candidates in biological control. In this study, effects of the gregarine Psychodiella sergenti Lantova, Volf, and Votypka on its natural host Phlebotomus sergenti Parrot were evaluated. The gregarines increased the mortality of immature sand fly stages, and this effect was even more apparent when the infected larvae were reared in more dense conditions. Similarly, the gregarines negatively affected the survival of adult males and females. However, no impact was observed on the mortality of blood-fed females, the proportion of females that laid eggs, and the number of eggs oviposited. The 10-times higher infection dose (50 versus five gregarine oocysts per one sand fly egg) led to -10 times more gamonts in fourth-instar larvae and two or three times more gamonts in females and males, respectively. Our study clearly shows that Ps. sergenti is harmful to its natural host under laboratory conditions. However, its potential for use in biological control is questionable as a result of several factors, including this parasite's strict host specificity. PMID:21936316

  18. Comparative surface morphology of marine coelomic gregarines (Apicomplexa, Urosporidae): Pterospora floridiensis and Pterospora schizosoma.

    PubMed

    Landers, Stephen C; Leander, Brian S

    2005-01-01

    Two species in the aseptate gregarine genus Pterospora from the Pacific and Gulf coasts were analyzed by scanning electron microscopy, which revealed characteristics not reported in other gregarines. The gamonts of these species had branching trunks that ended in terminal digits, and both species moved by cytoplasmic streaming and peristalsis. Pterospora floridiensis had surface pits and tracts of parallel ridges that bended and connected with one another. Pterospora schizosoma had irregular-shaped surface swellings that were usually arranged in rosette patterns. These unique surface features have not been reported for other gregarines, and are strikingly different from the surface features of many septate and aseptate gregarines that inhabit the intestinal lumena of their hosts and move by gliding. The correlation of Pterospora's unique pellicular features to the habitat and cytoplasmic streaming characteristic of the genus may be significant, and may reflect an adaptation for development in coelomic environments. PMID:15702976

  19. Monocystis apporectodae sp. nov. (Protozoa: Apicomplexa: Eugregarinida), from an Indian earthworm Apporectodea trapezoides Duges.

    PubMed

    Bandyopadhyay, Probir K; Mallik, Partha; Göçmen, Bayram; Mitra, Amlan Kumar

    2006-01-01

    A survey aimed at exploring the endoparasitic acephaline gregarine diversity in South-western Bengal, detected a new species of the genus Monocystis Stein, 1848, that resides in the seminal vesicles of the earthworm, Apporectodea trapezoides Duges collected in the district of Bankura from alluvial soil. Monocystis apporectodae sp. nov. is a ribbon-like organism with one or more prominent constric-tions especially in some mature forms and measures 178.0-224.0 (203.0+/-5.0) microm x 37.0-58.0 (46.0+/-1.5) microm. The extreme ends are pointed. Its gametocysts are ovoid and measure 108.0-118.0 microm (113.0+/-1.1) x 79.0-89.0 (83.0+/-1.1) microm. Oocysts are navicular in shape. The length of the oocysts ranges from 10.0-14.6 and the width, from 5.5-8.1 microm. PMID:17106856

  20. A new species of Choleoeimeria (Apicomplexa: Eimeriidae) from the lizard, Scincus hemprichii (Sauria: Scincidae).

    PubMed

    Abdel-Baki, Abdel-Azeem S; Al-Quraishy, Saleh; Abdel-Haleem, Heba M

    2013-07-01

    Four out of twenty (20%) specimens of the lizard Scincus hemprichii Wiegmann, collected in Saudi Arabia were infected with a previously undescribed species of Choleoeimeria. Oocysts of Choleoeimeria jazanensis sp. n. are cylindroidal, 26 x 15 microm, with a smooth bilayered wall and a shape index of 1.7. Oocyst residuum and micropyle are absent. Sporocysts are subspherical, 10 x 7 microm, with a shape index of 1.3. The Stieda body is absent. Sporozoites are banana-shaped, 10 x 3 microm, with one refractile body and enclosed the fine granulated sporocyst residuum. The endogenous development is confined to the gall bladder epithelium, with infected cells being displaced from the epithelium layer towards lumen. Mature meronts are subspherical and estimates to produce 9-12 merozoites. Microgamonts are spherical in shape with diameter of 13 microm. Macrogamonts are subspherical with a prominent nucleus in centre and wall-forming bodies at periphery. PMID:23951930

  1. Eimeria hemprichii n. sp. (Apicomplexa: Eimeriidae) from the lizard, Scincus hemprichii (Sauria: Scincidae) in Saudi Arabia.

    PubMed

    Alyousif, Mohamed Saleh; Al-Shawa, Yaser

    2005-12-01

    Eimeria hemprichii n. sp. was described from the gall bladder of the lizard, Scincus hemprichii captured at Gazan Province, western region, Saudi Arabia. Sporulated oocysts are ellipsoidal, 34.6x21.4 (32.5-36.3x20.7-22.5) microm. with smooth greenish-yellow bi-layered wall. Micropyle, polar granule and oocyst residuum are absent. Sporocysts are ellipsoidal, 11.6x8.0 (11.2-12.6 x7.5-8.4) microm. Sporosyst residuum is present, but without stieda or substiedal bodies. Sporozoites are elongate, laying head to tail in sporocyst and each one contains a single spherical posterior re-fracttile body. PMID:16333883

  2. Iron superoxide dismutases in eukaryotic pathogens: new insights from Apicomplexa and Trypanosoma structures.

    PubMed

    Phan, Isabelle Q H; Davies, Douglas R; Moretti, Nilmar Silvio; Shanmugam, Dhanasekaran; Cestari, Igor; Anupama, Atashi; Fairman, James W; Edwards, Thomas E; Stuart, Kenneth; Schenkman, Sergio; Myler, Peter J

    2015-05-01

    Prior studies have highlighted the potential of superoxide dismutases as drug targets in eukaryotic pathogens. This report presents the structures of three iron-dependent superoxide dismutases (FeSODs) from Trypanosoma cruzi, Leishmania major and Babesia bovis. Comparison with existing structures from Plasmodium and other trypanosome isoforms shows a very conserved overall fold with subtle differences. In particular, structural data suggest that B. bovis FeSOD may display similar resistance to peroxynitrite-mediated inactivation via an intramolecular electron-transfer pathway as previously described in T. cruzi FeSOD isoform B, thus providing valuable information for structure-based drug design. Furthermore, lysine-acetylation results in T. cruzi indicate that acetylation occurs at a position close to that responsible for the regulation of acetylation-mediated activity in the human enzyme. PMID:25961325

  3. Haemogregarine parasites (Apicomplexa: Hepatozoidae) in Caiman crocodilus yacare (Crocodilia: Alligatoridae) from Pantanal, Corumbá, MS, Brazil.

    PubMed

    Viana, Lúcio A; Marques, Eliézer J

    2005-01-01

    Haemogregarines were recorded in caimans Caiman crocodilus yacare from Pantanal. This study was carried out in seasonal ponds at the Miranda- Abobral subregion of Pantanal, State of Mato Grosso do Sul, western Brazil, from 1998 to 1999. Smears from 28 caimans were examined and 20 (71.4%) presented infection by a haemogregarine. Infections were observed in 11 males and 9 females. Morphological and morphometric observations suggest that the parasite forms found in this work are Hepatozoon caimani. PMID:16445875

  4. Caryospora uptoni n. sp. (Apicomplexa: Eimeriidae) from red-tailed hawks (Buteo jamaicensis borealis).

    PubMed

    Lindsay, D S; Blagburn, B L

    1986-10-01

    Oocysts of Caryospora uptoni n. sp. were described from the feces of red-tailed hawks, Buteo jamaicensis borealis. Sporulated oocysts were spherical or subspherical and measured 28.1 by 26.4 micron. The oocyst wall was composed of a yellowish outer layer and brownish inner layer and was about 1.5 micron thick. Neither micropyle, polar granules, nor oocyst residuum were present. A single, spherical sporocyst 18.2 by 17.9 micron was present; a Stieda body was absent. A spherical eccentrically located sporocyst residuum was present in many sporocysts, but it degenerated to form a dispersed granular residuum in other sporocysts. Eight randomly arranged sporozoites, 12.6 by 4.2 micron, were present in each sporocyst; they contained a centrally or slightly posteriorly located nucleus. PMID:3806324

  5. A novel Isospora species (Apicomplexa: Eimeriidae) from warblers (Passeriformes: Parulidae) of Costa Rica.

    PubMed

    Keeler, Shamus P; Yabsley, Michael J; Adams, Henry C; Hernandez, Sonia M

    2014-06-01

    Five of 16 (31%) rufous-capped warblers (Basileuterus rufifrons) and 2 of 5 (40%) ovenbirds ( Seiurus aurocapilla ) sampled from Costa Rica were positive for a novel species of Isospora. Oocysts have a thin, smooth, double-layered, colorless wall and measure 22.3 ?m ± 1.6 ?m × 24.3 ?m ± 1.5 ?m (19-25 ?m × 21-28 ?m) with an average length-width (L/W) ratio of 1.0 (1-1.3). Oocyst residuum and micropyle are absent, but 0-4 spherical to cigar-shaped polar granules (1-2.5 ?m) are present. Sporocysts are ovoid and measure 11.8 ?m ± 0.9 ?m × 16 ?m ± 1.7 ?m (10-14 ?m × 12-19 ?m) with an average L/W ratio of 1.6 (1.0-1.9). A knob-like Stieda body continuous with the sporocyst wall and a trapezoidal compartmentalized substieda body are present. Each sporocyst contained 4 sporozoites and a diffuse sporocyst residuum consisting of many variable-sized granules, some as large as 2 ?m. This is the second description of an Isospora species in New World warblers (Passeriformes: Parulidae) and the first report of Isospora from both the rufous-capped warbler and ovenbird. PMID:24456073

  6. Three new Hepatozoon species (Apicomplexa: Hepatozoidae) infecting the Florida kingsnake, Lampropeltis getula floridana.

    PubMed

    Telford, Sam R

    2010-02-01

    The Florida kingsnake, Lampropeltis getula floridana, is host to 3 species of Hepatozoon at the type locality, Miramar, Broward County, Florida, and 2, possibly all 3, species at Cedar Key, Levy County, approximately 480 km to the northwest. Hepatozoon eurytopis, n. sp. was present also in Diadophis punctatus and Elaphe guttata in Jupiter Farms, Palm Beach County, and in Thamnophis sirtalis at Gainesville, Alachua County. Specific identity in D. punctatus was determined from gamont morphology and from sporogonic stages and gamont morphology in the infections obtained from E. guttata and T. sirtalis. Infection with all 3 species by ingestion of infected mosquitoes was easily obtained in E. guttata, but only H. eurytopis produced experimental infection in T. sirtalis and Storeria occipitomaculata. Hepatozoon eurytopis differed from the other 2 species, H. karyolysi n. sp. and H. rexi n. sp., by its short and broad, recurved gamonts with average dimensions 11.2-13.1 x 4.5-5.4 microm, length x maximum width (LW) 56-64 microm(2), and L/W ratios 2.13-2.80 in all host species, large round oocysts 95-303 x 91-285 microm, L/W ratios 1.03-1.05 with spherical to ovoid sporocysts 22-50 x 21-44 microm, L/W ratios 1.00-1.82 that contain 33.5-44.4 (16-76) sporozoites. The nucleus in immature gamonts is highly irregular, often fragmented in separate masses of chromatin, and commonly appears to form binucleate gamonts before maturity. Hepatozoon karyolysi has elongate, non-recurved gamonts, 15-20 x 4-7 microm, LW 64-143 microm(2), L/W ratios 2.3-4.5 that usually cause lysis or irregular margins of the nucleus in infected erythrocytes of the type host. Oocysts are spherical, 127-243 x 122-233 microm, L/W ratio 1.0-1.1 that contain spherical to usually ovoid sporocysts 17-30 x 17-24 microm, and produce 12-20 sporozoites. Gamonts of Hepatozoon rexi are non-recurved, 14-18 x 4-6 microm, LW 67-102 microm(2), and L/W ratio 2.8-4.1, and are usually surrounded by a prominent cyst wall within the host erythrocyte. Oocysts are nearly spherical, 103-178 x 103-172 microm, form usually elongate sporocysts, 30-39 x 20-25 microm L/W ratio 1.33-1.94 that contain 16-36 sporozoites. An oocyst of H. eurytopis was present in the salivary gland of an infected Aedes aegypti , which is the second report of sporogony by a Hepatozoon species occurring in this site. PMID:19685939

  7. A new coccidian (Apicomplexa: Eimeriidae) from Galápagos tortoise, Chelonoidis sp. (Testudines: Testudinidae), from the Dallas Zoo.

    PubMed

    McAllister, Chris T; Duszynski, Donald W; Roberts, David T

    2014-02-01

    During January 1994, feces from a captive juvenile Galápagos tortoise, Chelonoidis sp., from the Dallas Zoo, Dallas County, Texas was examined for coccidia. The tortoise was found to harbor an eimerian which is described as new. Sporulated oocysts of Eimeria iversoni n. sp. were ovoidal with a smooth, single-layered wall (? 0.5-0.8) that measured (L × W) 13.5 × 10.3 ?m, with a length/width (L/W) ratio of 1.3; micropyle, oocyst residuum, and polar granule(s) were all absent; 2 conical projections were present on 1 end of oocyst and measured 1.0-1.5. Sporocysts were elongate-ellipsoidal and measured 8.3 × 4.5 ?m, with L/W of 1.8; a Stieda body (? 0.5 high) was present, but substieda and parastieda bodies were absent; a sporocyst residuum was composed of 2-5 granules in a compact mass between sporozoites; sporozoites were banana-shaped and measured 9.5 × 2.5 in situ, with an ellipsoidal posterior refractile body and a spheroidal anterior refractile body. This is only the second time an eimerian has been reported from Galápagos tortoises. PMID:24006862

  8. GOUSSIA GIRELLAE N. SP. (APICOMPLEXA: EIMERIORINA) IN THE OPALEYE, 'GIRELLA NIGRICANS' (JOURNAL VERSION)

    EPA Science Inventory

    Goussia girellae n. sp. is described from the opaleye fish, Girella nigricans. Merogonic stages were observed in the apices of intestinal epithelial cells, in the lamina propria, and in extraintestinal sites including liver, gills, and spleen. Gamonts were observed in the intesti...

  9. Cryptosporidium scrofarum n. sp. (Apicomplexa: Cryptosporidiidae) in domestic pigs (Sus scrofa).

    PubMed

    Kvá?, Martin; Kest?ánová, Michaela; Pinková, Martina; Kv?to?ová, Dana; Kalinová, Jana; Wagnerová, Pavla; Kotková, Michaela; Vítovec, Ji?í; Ditrich, Oleg; McEvoy, John; Stenger, Brianna; Sak, Bohumil

    2013-01-31

    We describe the morphological, biological, and molecular characteristics of Cryptosporidium pig genotype II and propose the species name Cryptosporidium scrofarum n. sp. to reflect its prevalence in adult pigs worldwide. Oocysts of C. scrofarum are morphologically indistinguishable from C. parvum, measuring 4.81-5.96 ?m (mean=5.16)×4.23-5.29 ?m (mean=4.83) with a length to width ratio of 1.07±0.06 (n=400). Oocysts of C. scrofarum obtained from a naturally infected pig were infectious for 8-week-old pigs but not 4-week-old pigs. The prepatent period in 8-week-old Cryptosporidium-naive pigs was 4-6 days and the patent period was longer than 30 days. The infection intensity of C. scrofarum in pigs was generally low, in the range 250-4000 oocysts per gram of feces. Infected pigs showed no clinical signs of cryptosporidiosis and no pathology was detected. Cryptosporidium scrofarum was not infectious for adult SCID mice, adult BALB/c mice, Mongolian gerbils (Meriones unguiculatus), southern multimammate mice (Mastomys coucha), yellow-necked mice (Apodemus flavicollis), or guinea pigs (Cavia porcellus). Phylogenetic analyses based on small subunit rRNA, actin, and heat shock protein 70 gene sequences revealed that C. scrofarum is genetically distinct from all known Cryptosporidium species. PMID:23021264

  10. A new species of Cryptosporidium (Apicomplexa: Cryptosporidiidae) from eastern grey kangaroos (Macropus giganteus).

    PubMed

    Power, Michelle L; Ryan, Una M

    2008-10-01

    Cryptosporidium macropodum n. sp is described. Oocysts of C. macropodum from the feces of kangaroos (Macropus spp.) are morphologically indistinguishable from other mammalian Cryptosporidium species, including C. parvum, C. hominis, C. suis, and C. canis. The oocysts are fully sporulated on excretion, lack sporocysts, and have an average width of 4.9 microm (4.5-6.0), a length of 5.4 microm (5.0-6.0), and a length:width ratio of 1.1. Phylogenetic analyses of the 18S ribosomal RNA, actin, and heat shock protein 70 (HSP70) loci demonstrate that C. macropodum is genetically distinct from all described Cryptosporidium species, including others found in marsupials. The parasite seems to be highly host-specific, because it has been found only in marsupials to date. Therefore, based on biological and molecular data, we consider C. macropodum a new species. PMID:18973420

  11. Life cycle of Cystoisospora felis (Coccidia: Apicomplexa) in cats and mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cystoisospora felis is a ubiquitous apicomplexan protozoon of cats. The endogenous development of C. felis was studied in cats after feeding them infected mice. For this, 5 newborn cats were killed at 24, 48, 72, 96, and 120 h after having been fed mesenteric lymph nodes and spleens of mice that wer...

  12. A new Eimeria species (Apicomplexa: Eimeriidae) infecting Onychomys species (Rodentia: Muridae) in New Mexico and Arizona.

    PubMed

    Hnida, J A; Wilson, W D; Duszynski, D W

    1998-12-01

    Fecal samples from 3 species of Onychomys (Rodentia: Muridae) captured in New Mexico and Arizona were examined for coccidia. Six of the 59 (10%) were infected with a new species of Eimeria. Sporulated oocysts (n = 105) of this new species are subspheroidal, 17.4 x 16.1 (14-21 x 13-19) microm, with ellipsoidal sporocysts 10.4 x 5.7 (9-12 x 5-8) microm. This species occurred in 3 of 24 (13%) Onychomys arenicola, 2 of 31 (6%) Onychomys leucogaster from New Mexico, and 1 of 4 (25%) Onychomys torridus from Arizona. Isolates recovered from O. leucogaster and O. torridus were inoculated into O. leucogaster (n = 5) and produced infections with a prepatent period of 7 days and a patent period of 7-23 days. PMID:9920315

  13. Sex allocation and population structure in apicomplexan (protozoa) parasites.

    PubMed Central

    West, S A; Smith, T G; Read, A F

    2000-01-01

    Establishing the selfing, rate of parasites is important for studies in clinical and epidemiological medicine as well as evolutionary biology Sex allocation theory offers a relatively cheap and easy way to estimate selfing rates in natural parasite populations. Local mate competition (LMC) theory predicts that the optimal sex ratio (r*; defined as proportion males) is related to the selfing rate (s) by the equation r* = (1-s)/2. In this paper, we generalize the application of sex allocation theory across parasitic protozoa in the phylum Apicomplexa. This cosmopolitan phylum consists entirely of parasites, and includes a number of species of medical and veterinary importance. We suggest that LMC theory should apply to eimeriorin intestinal parasites. As predicted, data from 13 eimeriorin species showed a female-biased sex ratio, with the sex ratios suggesting high levels of selfing (0.8-1.0). Importantly, our estimate of the selfing rate in one of these species, Toxoplasma gondii, is in agreement with previous genetic analyses. In contrast, we predict that LMC theory will not apply to the groups in which syzygy occurs (adeleorins, gregarines and piroplasms). Syzygy occurs when a single male gametocyte and a single female gametocyte pair together physically or in close proximity, just prior to fertilization. As predicted, data from four adeleorin species showed sex ratios not significantly different from 0.5. PMID:10714880

  14. Sex allocation and population structure in apicomplexan (protozoa) parasites.

    PubMed

    West, S A; Smith, T G; Read, A F

    2000-02-01

    Establishing the selfing, rate of parasites is important for studies in clinical and epidemiological medicine as well as evolutionary biology Sex allocation theory offers a relatively cheap and easy way to estimate selfing rates in natural parasite populations. Local mate competition (LMC) theory predicts that the optimal sex ratio (r*; defined as proportion males) is related to the selfing rate (s) by the equation r* = (1-s)/2. In this paper, we generalize the application of sex allocation theory across parasitic protozoa in the phylum Apicomplexa. This cosmopolitan phylum consists entirely of parasites, and includes a number of species of medical and veterinary importance. We suggest that LMC theory should apply to eimeriorin intestinal parasites. As predicted, data from 13 eimeriorin species showed a female-biased sex ratio, with the sex ratios suggesting high levels of selfing (0.8-1.0). Importantly, our estimate of the selfing rate in one of these species, Toxoplasma gondii, is in agreement with previous genetic analyses. In contrast, we predict that LMC theory will not apply to the groups in which syzygy occurs (adeleorins, gregarines and piroplasms). Syzygy occurs when a single male gametocyte and a single female gametocyte pair together physically or in close proximity, just prior to fertilization. As predicted, data from four adeleorin species showed sex ratios not significantly different from 0.5. PMID:10714880

  15. Kinetic modeling of Toxoplasma gondii invasion

    PubMed Central

    Kafsack, Björn F.C.; Carruthers, Vern B.; Pineda, Fernando J.

    2009-01-01

    The phylum Apicomplexa includes parasites responsible for global scourges such as malaria, cryptosporidiosis, and toxoplasmosis. Parasites in this phylum reproduce inside the cells of their hosts, making invasion of host cells an essential step of their life cycle. Characterizing the stages of host-cell invasion, has traditionally involved tedious microscopic observations of individual parasites over time. As an alternative, we introduce the use of compartment models for interpreting data collected from snapshots of synchronized populations of invading parasites. Parameters of the model are estimated via a maximum negative log-likelihood principle. Estimated parameter values and their 95% confidence intervals (95% CI), are consistent with reported observations of individual parasites. For RH-strain parasites, our model yields that: 1) penetration of the host cell plasma membrane takes 26 sec (95% CI: 22-30 sec), 2) parasites that ultimately invade, remained attached 3 times longer than parasites that eventually detach from the host cells, and 3) 25% (95% CI: 19-33%) of parasites invade while 75% (95% CI: 67-81%) eventually detach from their host cells without progressing to invasion. A key feature of the model is the incorporation of invastion stages that cannot be directly observed. This allows us to characterize the phenomenon, of parasite detachment from host cells. The properties of this phenomenon would be difficult to quantify without a mathematical model. We conclude that mathematical modeling provides a powerful new tool for characterizing the stages of host-cell invasion by intracellular parasites. PMID:17942124

  16. Galactose Recognition by the Apicomplexan Parasite Toxoplasma gondii*

    PubMed Central

    Marchant, Jan; Cowper, Ben; Liu, Yan; Lai, Livia; Pinzan, Camila; Marq, Jean Baptiste; Friedrich, Nikolas; Sawmynaden, Kovilen; Liew, Lloyd; Chai, Wengang; Childs, Robert A.; Saouros, Savvas; Simpson, Peter; Roque Barreira, Maria Cristina; Feizi, Ten; Soldati-Favre, Dominique; Matthews, Stephen

    2012-01-01

    Toxosplasma gondii is the model parasite of the phylum Apicomplexa, which contains numerous obligate intracellular parasites of medical and veterinary importance, including Eimeria, Sarcocystis, Cryptosporidium, Cyclospora, and Plasmodium species. Members of this phylum actively enter host cells by a multistep process with the help of microneme protein (MIC) complexes that play important roles in motility, host cell attachment, moving junction formation, and invasion. T. gondii (Tg)MIC1-4-6 complex is the most extensively investigated microneme complex, which contributes to host cell recognition and attachment via the action of TgMIC1, a sialic acid-binding adhesin. Here, we report the structure of TgMIC4 and reveal its carbohydrate-binding specificity to a variety of galactose-containing carbohydrate ligands. The lectin is composed of six apple domains in which the fifth domain displays a potent galactose-binding activity, and which is cleaved from the complex during parasite invasion. We propose that galactose recognition by TgMIC4 may compromise host protection from galectin-mediated activation of the host immune system. PMID:22399295

  17. Thermogutta terrifontis gen. nov., sp. nov. and Thermogutta hypogea sp. nov., thermophilic anaerobic representatives of the phylum Planctomycetes.

    PubMed

    Slobodkina, Galina B; Kovaleva, Olga L; Miroshnichenko, Margarita L; Slobodkin, Alexander I; Kolganova, Tatyana V; Novikov, Andrei A; van Heerden, Esta; Bonch-Osmolovskaya, Elizaveta A

    2015-03-01

    Two novel strains of thermophilic planctomycetes were recovered from terrestrial and subterranean habitats. Strain R1(T) was isolated from a hot spring (Kunashir Island, Russia) and strain SBP2(T) was isolated from a deep gold mine (South Africa). Both isolates grew in the temperature range 30-60 °C and pH range 5.0-8.0. Strain R1(T) grew optimally at 60 °C and pH 6.0-6.5; for SBP2(T) optimal conditions were at 52 °C and pH 7.5-8.0. Both strains were capable of anaerobic respiration with nitrate and nitrite as electron acceptors as well as of microaerobic growth. They also could grow by fermentation of mono-, di- and polysaccharides. Based on their phylogenetic position and phenotypic features we suggest that the new isolates represent two novel species belonging to a new genus in the order Planctomycetales, for which the names Thermogutta terrifontis gen. nov., sp. nov. and Thermogutta hypogea sp. nov. are proposed. The type strain of Thermogutta terrifontis, the type species of the genus, is R1(T) (?=?DSM 26237(T)?=?VKM B-2805(T)), and the type strain of Thermogutta hypogea is SBP2(T) (?=?JCM 19991(T)?=?VKM B-2782(T)). PMID:25479950

  18. 'CANDIDATUS PAENICARDINIUM ENDOI', AN ENDOSYMBIONT OF THE PLANT-PARASITIC NEMATODE HETERODERA GLYCINES (NEMATA: TYLENCHIDA), AFFILIATED TO THE PHYLUM BACTERIODETES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During TEM studies of females of the plant-parasitic nematodes Globodera rostochiensis and Heterodera goettingiana and juveniles of H. glycines conducted in the 1970s, bacteria-like endosymbionts were observed. These organisms were characterized as being rod-shaped ranging in size from 0.3 – 0.5 um...

  19. Vavraia lutzomyiae n. sp. (Phylum Microspora) infecting the sandfly Lutzomyia longipalpis (Psychodidae, Phlebotominae), a vector of human visceral leishmaniasis

    Microsoft Academic Search

    Edilson Matos; Ivete Mendonça; Carlos Azevedo

    2006-01-01

    Vavraia lutzomyiae (Microsporida; Pleistophoridae) is a new species parasitic in the tropical phlebotomine sandfly, Lutzomyia longipalpis (Diptera, Psychodidae, Phlebotominae), a major vector of Leishmania chagasi in Latin America where human visceral leishmaniasis is endemic. Infected larvae and pupae were parasitized in the abdomen, and some adults were parasitized in Malpighian tubules and midgut. The sporogonial plasmodium divided by multiple divisions

  20. Metal Dealing at the Origin of the Chordata Phylum: The Metallothionein System and Metal Overload Response in Amphioxus

    Microsoft Academic Search

    Maria Guirola; Sílvia Pérez-Rafael; Mercè Capdevila; Òscar Palacios; Sílvia Atrian

    2012-01-01

    Non-vertebrate chordates, specifically amphioxus, are considered of the utmost interest for gaining insight into the evolutionary trends, i.e. differentiation and specialization, of gene\\/protein systems. In this work, MTs (metallothioneins), the most important metal binding proteins, are characterized for the first time in the cephalochordate subphylum at both gene and protein level, together with the main features defining the amphioxus response

  1. Microbial Reductive Dechlorination of Aroclor 1260 in Baltimore Harbor Sediment Microcosms Is Catalyzed by Three Phylotypes within the Phylum Chloroflexi

    Microsoft Academic Search

    Sonja K. Fagervold; Harold D. May; Kevin R. Sowers

    2007-01-01

    The specific dechlorination pathways for Aroclor 1260 were determined in Baltimore Harbor sediment microcosms developed with the 11 most predominant congeners from this commercial mixture and their resulting dechlorination intermediates. Most of the polychlorinated biphenyl (PCB) congeners were dechlo- rinated in the meta position, and the major products were tetrachlorobiphenyls with unflanked chlorines. Using PCR primers specific for the 16S

  2. Microbial Reductive Dechlorination of Aroclor 1260 in Baltimore Harbor Sediment Microcosms Is Catalyzed by Three Phylotypes within the Phylum Chloroflexi?

    PubMed Central

    Fagervold, Sonja K.; May, Harold D.; Sowers, Kevin R.

    2007-01-01

    The specific dechlorination pathways for Aroclor 1260 were determined in Baltimore Harbor sediment microcosms developed with the 11 most predominant congeners from this commercial mixture and their resulting dechlorination intermediates. Most of the polychlorinated biphenyl (PCB) congeners were dechlorinated in the meta position, and the major products were tetrachlorobiphenyls with unflanked chlorines. Using PCR primers specific for the 16S rRNA genes of known PCB-dehalogenating bacteria, we detected three phylotypes within the microbial community that had the capability to dechlorinate PCB congeners present in Aroclor 1260 and identified their selective activities. Phylotype DEH10, which has a high level of sequence identity to Dehalococcoides spp., removed the double-flanked chlorine in 234-substituted congeners and exhibited a preference for para-flanked meta-chlorines when no double-flanked chlorines were available. Phylotype SF1 had similarity to the o-17/DF-1 group of PCB-dechlorinating bacteria. Phylotype SF1 dechlorinated all of the 2345-substituted congeners, mostly in the double-flanked meta position and 2356-, 236-, and 235-substituted congeners in the ortho-flanked meta position, with a few exceptions. A phylotype with 100% sequence identity to PCB-dechlorinating bacterium o-17 was responsible for an ortho and a double-flanked meta dechlorination reaction. Most of the dechlorination pathways supported the growth of all three phylotypes based on competitive PCR enumeration assays, which indicates that PCB-impacted environments have the potential to sustain populations of these PCB-dechlorinating microorganisms. The results demonstrate that the variation in dechlorination patterns of congener mixtures typically observed at different PCB impacted sites can potentially be mediated by the synergistic activities of relatively few dechlorinating species. PMID:17351091

  3. Report of wood decay fungus Inonotus tropicalis (phylum Basidiomycota) from a dog with a granulomatous mediastinal mass.

    PubMed

    Sheppard, Barbara J; McGrath, Elizabeth; Giuffrida, Michelle; Craft, Serena L M; Kung, Chung Yee; Smith, Matthew E

    2013-09-01

    A 75.9-kg, 3.5-year-old male Irish Wolfhound dog with a 2-3-week history of gagging and eating difficulties was referred to the University of Florida Veterinary Medical Hospital (Gainesville, Florida) for evaluation of a large cranial mediastinal mass suspected to be a thymoma or lymphosarcoma. The patient had 4 months of nearly 10 kg progressive weight loss with severe flank sensitivity and radiographically apparent lumbar vertebral changes interpreted as discospondylitis. Lab work revealed hyperglobulinemia, mild proteinuria, normal T4, negative Brucella canis titer, and negative blood and urine bacterial cultures. A thoracotomy revealed a nonresectable, destructive, space-occupying mediastinal mass resulting in euthanasia without surgical recovery. Biopsies from the mass were collected during surgery for histology. Microscopic examination revealed extensive granulomatous cellulitis and lymphadenitis characterized by central cavitated necrotic areas containing debris and degenerate neutrophils, intermediate zones of fibrovascular proliferation with marked mixed inflammation, peripheral fibrosis, frequent multinucleated macrophages, and scattered mineralization. The necrotic material contained dense mats of 2 µm wide by 8-15 µm long fungal hyphae with parallel walls, acute angle branching, frequent septae, and occasional bulb-like dilations. DNA sequencing and phylogenetic analysis of the internal transcribed spacer region confirmed the presence of a fungus in the Inonotus tropicalis group. Inonotus tropicalis is primarily a wood decay fungus that is found on dead wood from angiosperms in tropical and subtropical habitats. Isolates of the I. tropicalis group have been detected a few times from immunosuppressed human beings with X-linked granulomatous disease. PMID:23929678

  4. A new species of Dicyemennea Whitman, 1883 (Phylum Dicyemida) from Sepia latimanus (Mollusca: Cephalopoda: Decapodidae) off Okinawa, Japan.

    PubMed

    Furuya, Hidetaka

    2006-11-01

    A new species of dicyemid mesozoan is described from a cuttlefish Sepia latimanus Quoy and Gaimard collected off Nago, Naha and Onnason, Okinawa Islands, Ryukyu Islands, Japan. Dicyemennea ryukyuense n. sp. is a large species that reaches about 5 mm in length. The vermiform stage is characterised by 23 peripheral cells, a conical calotte and an axial cell that extends to the base of the propolar cells. The infusoriform embryo consists of 37 cells; two nuclei are present in each urn cell and the refringent bodies are solid. In the type of reproductive strategy, rhombogens of D. ryukyuense form a small number of infusorigens and produce a relatively large number of gametes per infusorigen. In the family Dicyemidae, Dicyemennea Whitman, 1883 is the largest group after Dicyema von Kölliker, 1849. Other dicyemid species, including those belonging to Dicyema, were not detected. Dicyemids have never previously been detected in cephalopods living on corals and rocks off the Ryukyu Islands, even though they are benthonic in habitat. This is the first report of a dicyemid mesozoan from S. latimanus and also from off the Ryukyu Islands. S. latimanus inhabits coral reefs, often swimming over the coral but usually lying on the sandy bottom. Dicyemids cannot possibly infect cephalopods which live exclusively over coral and rock. PMID:16955340

  5. Spatiotemporal Changes in the Structure and Composition of a Less-Abundant Bacterial Phylum (Planctomycetes) in Two Perialpine Lakes ? †

    PubMed Central

    Pollet, Thomas; Tadonléké, Rémy D.; Humbert, Jean François

    2011-01-01

    We used fingerprinting and cloning-sequencing to study the spatiotemporal dynamics and diversity of Planctomycetes in two perialpine lakes with contrasting environmental conditions. Planctomycetes, which are less-abundant bacteria in freshwater ecosystems, appeared to be structured in the same way as the entire bacterial community in these ecosystems. They were more diversified and displayed fewer temporal variations in the hypolimnia than in the epilimnia. Like the more-abundant bacterial groups in aquatic systems, Planctomycetes communities seem to be composed of a very small number of abundant and widespread operational taxonomic units (OTUs) and a large number of OTUs that are present at low abundance. This indicates that the concept of “abundant or core” and “rare” bacterial phylotypes could also be applied to less-abundant freshwater bacterial phyla. The richness and diversity of Planctomycetes were mainly driven by pH and were similar in both of the lakes studied, whereas the composition of the Planctomycetes community seemed to be determined by a combination of factors including temperature, pH, and nutrients. The relative abundances of the dominant OTUs varied over time and were differently associated with abiotic factors. Our findings demonstrate that less-abundant bacterial phyla, such as Planctomycetes, can display strong spatial and seasonal variations linked to environmental conditions and suggest that their functional role in the lakes studied might be attributable mainly to a small number of phylotypes and vary over space and time in the water column. PMID:21602381

  6. Archaea-like genes for C1-transfer enzymes in Planctomycetes: phylogenetic implications of their unexpected presence in this phylum.

    PubMed

    Bauer, Margarete; Lombardot, Thierry; Teeling, Hanno; Ward, Naomi L; Amann, Rudolf I; Glöckner, Frank O

    2004-11-01

    The unexpected presence of archaea-like genes for tetrahydromethanopterin (H4MPT)-dependent enzymes in the completely sequence geiome of the aerobic marine planctomycete Pirellula sp. strain 1 ("Rhodopirellula baltica") and in the currently sequenced genome of the aerobic freshwater planctomycete Gemmata obscuriglobus strain UQM2246 revives the discussion on the origin of these genes in the bacterial domain. We compared the genomic arrangement of these genes in Planctomyetes and methylotrophic proteobacteria and perormed a phylogenetic analysis of the encoded protein sequences to address the question whether the genes have been present in the common ancestor of Bacteria and Archaea or were transferred laterally from the archaeal to the bacterial domain and herein. Although this question could not be solved using the data presented here, some constraints on the evolution of the genes involved in archaeal and )acterial H4MPT-dependent C1-transfer may be proposed: (i) lateral gene transfer (LGT) from Archea to a common ancestor of Proteobacteria and Planctomycetes seems more likely than the presence of the genes in the common ancestor of Bacteria and Archaea; (ii) a single event of interdomain LGT can e favored over two independent events; and (iii) the irchacal donor of the genes might have been a repesentative of the Methanosarcinales. In the bacterial domain, the acquired genes evolved according to distinct environmental and metabolic constraints, reflected by specific rearrangements of gene order, gene recruitment, and gene duplication, with subsequent functional specialization. During the course of evolution, genes were lost from some planctomycete genomes or replaced by orthologous genes from proteobacterial lineages. PMID:15693614

  7. Reproductive biology of the deep-water coral Acanella arbuscula (Phylum Cnidaria: Class Anthozoa: Order Alcyonacea), northwest Atlantic

    NASA Astrophysics Data System (ADS)

    Beazley, Lindsay I.; Kenchington, Ellen L.

    2012-10-01

    Knowledge of the reproductive life-history of deep-water corals is important for assessing their vulnerability to anthropogenic impacts. Yet, the reproductive biology of many deep-water corals, especially members of the subclass Octocorallia, has not been examined. We used histological techniques to describe the reproductive biology of the deep-water gorgonian coral Acanella arbuscula from the northwest Atlantic. All colonies examined were gonochoric, and no embryos or planula larvae were observed in the polyps. Mean polyp-level fecundity (females: 21.0±17.5 oocytes polyp-1, and males: 13.9±13.5 sperm sacs polyp-1) is high compared to other deep-water gorgonians, and polyps closer to the branch tips had the highest fecundities in both females and males. The presence of large oocytes (maximum diameter 717.8 ?m) suggests that A. arbuscula produces lecithotrophic larvae. Despite the potentially high fecundity and small size at first reproduction, the paucity of information on dispersal and recruitment, combined with its longevity, vulnerability to bottom fishing gear, and ecological role as a structure-forming species, still warrants the classification of A. arbuscula as a vulnerable marine ecosystem indicator.

  8. Carnets de Gologie / Notebooks on Geology -Article 2006/03 (CG2006_A03) Are the green algae (phylum Viridiplantae)

    E-print Network

    Paris-Sud XI, Université de

    Carnets de Géologie / Notebooks on Geology - Article 2006/03 (CG2006_A03) 1 Are the green algae planet, A.H. KNOLL states that the first documented fossils of green algae date back 750 Ma. However" and of a primitive clade of green algae, the Pyramimonadales. A paraphyletic group of unicellular green algae, named

  9. Draft Genome Sequence of Tatumella sp. Strain UCD-D_suzukii (Phylum Proteobacteria) Isolated from Drosophila suzukii Larvae

    PubMed Central

    Dunitz, Madison I.; James, Pamela M.; Jospin, Guillaume; Coil, David A.; Chandler, James Angus

    2014-01-01

    Here we present the draft genome of Tatumella sp. strain UCD-D_suzukii, the first member of this genus to be sequenced. The genome contains 3,602,931 bp in 72 scaffolds. This strain was isolated from Drosophila suzukii larvae as part of a larger project to study the microbiota of D. suzukii. PMID:24762940

  10. Draft Genome Sequence of Tatumella sp. Strain UCD-D_suzukii (Phylum Proteobacteria) Isolated from Drosophila suzukii Larvae.

    PubMed

    Dunitz, Madison I; James, Pamela M; Jospin, Guillaume; Eisen, Jonathan A; Coil, David A; Chandler, James Angus

    2014-01-01

    Here we present the draft genome of Tatumella sp. strain UCD-D_suzukii, the first member of this genus to be sequenced. The genome contains 3,602,931 bp in 72 scaffolds. This strain was isolated from Drosophila suzukii larvae as part of a larger project to study the microbiota of D. suzukii. PMID:24762940

  11. Reconstructing SALMFamide Neuropeptide Precursor Evolution in the Phylum Echinodermata: Ophiuroid and Crinoid Sequence Data Provide New Insights

    PubMed Central

    Elphick, Maurice R.; Semmens, Dean C.; Blowes, Liisa M.; Levine, Judith; Lowe, Christopher J.; Arnone, Maria I.; Clark, Melody S.

    2015-01-01

    The SALMFamides are a family of neuropeptides that act as muscle relaxants in echinoderms. Analysis of genome/transcriptome sequence data from the sea urchin Strongylocentrotus purpuratus (Echinoidea), the sea cucumber Apostichopus japonicus (Holothuroidea), and the starfish Patiria miniata (Asteroidea) reveals that in each species there are two types of SALMFamide precursor: an L-type precursor comprising peptides with a C-terminal LxFamide-type motif and an F-type precursor solely or largely comprising peptides with a C-terminal FxFamide-type motif. Here, we have identified transcripts encoding SALMFamide precursors in the brittle star Ophionotus victoriae (Ophiuroidea) and the feather star Antedon mediterranea (Crinoidea). We have also identified SALMFamide precursors in other species belonging to each of the five echinoderm classes. As in S. purpuratus, A. japonicus, and P. miniata, in O. victoriae there is one L-type precursor and one F-type precursor. However, in A. mediterranea only a single SALMFamide precursor was found, comprising two peptides with a LxFamide-type motif, one with a FxFamide-type motif, five with a FxLamide-type motif, and four with a LxLamide-type motif. As crinoids are basal to the Echinozoa (Holothuroidea?+?Echinoidea) and Asterozoa (Asteroidea?+?Ophiuroidea) in echinoderm phylogeny, one model of SALMFamide precursor evolution would be that ancestrally there was a single SALMFamide gene encoding a variety of SALMFamides (as in crinoids), which duplicated in a common ancestor of the Echinozoa and Asterozoa and then specialized to encode L-type SALMFamides or F-type SALMFamides. Alternatively, a second SALMFamide precursor may remain to be discovered or may have been lost in crinoids. Further insights will be obtained if SALMFamide receptors are identified, which would provide a molecular basis for experimental analysis of the functional significance of the “cocktails” of SALMFamides that exist in echinoderms. PMID:25699014

  12. Symbiosis and Insect Diversification: an Ancient Symbiont of Sap-Feeding Insects from the Bacterial Phylum Bacteroidetes

    Microsoft Academic Search

    Nancy A. Moran; Phat Tran; Nicole M. Gerardo

    2005-01-01

    Several insect groups have obligate, vertically transmitted bacterial symbionts that provision hosts with nutrients that are limiting in the diet. Some of these bacteria have been shown to descend from ancient infections. Here we show that the large group of related insects including cicadas, leafhoppers, treehoppers, spittlebugs, and planthoppers host a distinct clade of bacterial symbionts. This newly described symbiont

  13. Metabolic Reprogramming During Purine Stress in the Protozoan Pathogen Leishmania donovani

    SciTech Connect

    Martin, Jessica L.; Yates, Phillip A.; Soysa, Radika; Alfaro, Joshua F.; Yang, Feng; Burnum-Johnson, Kristin E.; Petyuk, Vladislav A.; Weitz, Karl K.; Camp, David G.; Smith, Richard D.; Wilmarth, Phillip A.; David, Larry L.; Ramasamy, Gowthaman; Myler, Peter J.; Carter, Nicola S.

    2014-02-27

    The ability of Leishmania to survive in their insect or mammalian host is dependent upon an ability to sense and adapt to changes in the microenvironment. However, little is known about the molecular mechanisms underlying the parasite response to environmental changes, such as nutrient availability. To elucidate nutrient stress response pathways in Leishmania donovani, we have used purine starvation as the paradigm. The salvage of purines from the host milieu is obligatory for parasite replication; nevertheless, purine-starved parasites can persist in culture without supplementary purine for over 3 months, indicating that the response to purine starvation is robust and engenders parasite survival under conditions of extreme scarcity. To understand metabolic reprogramming during purine starvation we have employed global approaches. Whole proteome comparisons between purine-starved and purine-replete parasites over a 6-48 h span have revealed a temporal and coordinated response to purine starvation. Purine transporters and enzymes involved in acquisition at the cell surface are upregulated within a few hours of purine removal from the media, while other key purine salvage components are upregulated later in the time-course and more modestly. After 48 h, the proteome of purine-starved parasites is extensively remodeled and adaptations to purine stress appear tailored to deal with both purine deprivation and general stress. To probe the molecular mechanisms affecting proteome remodeling in response to purine starvation, comparative RNA-seq analyses, qRT-PCR, and luciferase reporter assays were performed on purine-starved versus purine-replete parasites. While the regulation of a minority of proteins tracked with changes at the mRNA level, for many regulated proteins it appears that proteome remodeling during purine stress occurs primarily via translational and/or post-translational mechanisms.

  14. An immobilization antigen gene of the fish-parasitic protozoan Ichthyophthirius multifiliis strain ARS-6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ichthyophthirius multifiliis (Ich) is a severe fish parasite that causes ‘white spot’ disease in many freshwater fish and leads to high mortality. The antigens on the parasite surface are involved in the antibody-mediated immobilization and hence designated as immobilization antigens (i-antigens). ...

  15. Characterization of a novel Obg-like ATPase in the protozoan Trypanosoma cruzi

    Microsoft Academic Search

    Daniela F. Gradia; Karlan Rau; Adriana C. S. Umaki; Flavia S. P. de Souza; Christian M. Probst; Alejandro Correa; Fabíola B. Holetz; Andréa R. Avila; Marco A. Krieger; Samuel Goldenberg; Stenio P. Fragoso

    2009-01-01

    We characterized a gene encoding an YchF-related protein, TcYchF, potentially associated with the protein translation machinery of Trypanosoma cruzi. YchF belongs to the translation factor-related (TRAFAC) class of P-loop NTPases. The coding region of the gene is 1185bp long and encodes a 44.3kDa protein. BlastX searches showed TcYchF to be very similar (45–86%) to putative GTP-binding proteins from eukaryotes, including

  16. Detoxication of zinc and cadmium by the freshwater protozoan Tetrahymena pyriformis: the effect of water hardness

    SciTech Connect

    Chapman, G.; Dunlop, S.

    1981-10-01

    Estimated 8-hr LC/sub 50/ values of zinc and cadmium were less than 1 ppm in the absence of soluble calcium and magnesium, but were raised, for example, to 24 ppm of zinc and 19 ppm of cadmium by the addition of calcium plus magnesium at a concentration (500 ppm) equivalent to that of very hard water. Experiments with /sup 65/Zn showed that uptake of this element from sublethal concentrations over 8 hr was reduced from approximately 50 X 10/sup -2/ ..mu..g liter/sup -1/ to 10 X 10/sup -2/ ..mu..g liter/sup -1/ per 10/sup 6/ cells by the addition of 500 ppm of calcium and magnesium. Diminished uptake may partly explain the antagonism observed in the toxicity tests.

  17. Tolerance of ciliated protozoan Paramecium bursaria (Protozoa, Ciliophora) to ammonia and nitrites

    NASA Astrophysics Data System (ADS)

    Xu, Henglong; Song, Weibo; Lu, Lu; Alan, Warren

    2005-09-01

    The tolerance to ammonia and nitrites in freshwater ciliate Paramecium bursaria was measured in a conventional open system. The ciliate was exposed to different concentrations of ammonia and nitrites for 2h and 12h in order to determine the lethal concentrations. Linear regression analysis revealed that the 2h-LC50 value for ammonia was 95.94 mg/L and for nitrite 27.35 mg/L using probit scale method (with 95% confidence intervals). There was a linear correlation between the mortality probit scale and logarithmic concentration of ammonia which fit by a regression equation y=7.32 x 9.51 ( R 2=0.98; y, mortality probit scale; x, logarithmic concentration of ammonia), by which 2 h-LC50 value for ammonia was found to be 95.50 mg/L. A linear correlation between mortality probit scales and logarithmic concentration of nitrite is also followed the regression equation y=2.86 x+0.89 ( R 2=0.95; y, mortality probit scale; x, logarithmic concentration of nitrite). The regression analysis of toxicity curves showed that the linear correlation between exposed time of ammonia-N LC50 value and ammonia-N LC50 value followed the regression equation y=2 862.85 e -0.08 x ( R 2=0.95; y, duration of exposure to LC50 value; x, LC50 value), and that between exposed time of nitrite-N LC50 value and nitrite-N LC50 value followed the regression equation y=127.15 e -0.13 x ( R 2=0.91; y, exposed time of LC50 value; x, LC50 value). The results demonstrate that the tolerance to ammonia in P. bursaria is considerably higher than that of the larvae or juveniles of some metozoa, e.g. cultured prawns and oysters. In addition, ciliates, as bacterial predators, are likely to play a positive role in maintaining and improving water quality in aquatic environments with high-level ammonium, such as sewage treatment systems.

  18. Ultraviolet light photobiology of the protozoan Tetrahymena pyriformis and chemical reactivation of DNA damage

    SciTech Connect

    Wheeler, J.S.

    1988-01-01

    The tunable dye laser was developed in order to perform UV-B and UV-C (254-320 nm) action spectra studies on several different organisms. Using the laser, action spectra studies have been performed for Escherichia coli, Saccharomyces, Chlamydomonas, Caenorhabditis elegans, Paramecium, and Tetrahymena pyriformis. Studies generally indicate increasing LD{sub 50} values with increasing wavelength. Two notable findings were made: (1) The action spectra does not follow the DNA absorption spectra at 280, 290 and 295 nm; (2) The repair competent/repair defective sensitization factor does not remain constant throughout the wavelength region. In addition it was found that the repair defective strain of E. coli, Bs-1, showed an increase in survival with increasing UV irradiation, at certain dose levels. Further experiments were designed to better characterize the reactivation. Tetrahymena were exposed to UV-C and reactivated with methyl methanesulfonate (MMS) and 4-nitro quinoline oxide (4-NQO). In both cases survival was seen to increase after chemical exposure. Likewise, UV-C was found to reactivate chemical damage (MMS).

  19. Elucidation of the life cycle of the intestinal protozoan Blastocystis hominis

    Microsoft Academic Search

    M. Singh; K. Suresh; L. C. Ho; G. C. Ng; E. H. Yap

    1995-01-01

    This paper elucidates the status of the different morphological forms ofBlastocystis and reports the existence of thin-and thick-walled cysts inB. hominis on the basis of current experimental evidence. It is suggested that the thin-walled cysts are autoinfectious, leading to multiplication of the organism in the intestinal tract. The thick-walled cysts are responsible for external transmission via the faecal-oral route. A

  20. Transport behavior of groundwater protozoa and protozoan-sized microspheres in sandy aquifer sediments

    USGS Publications Warehouse

    Harvey, R.W.; Kinner, N.E.; Bunn, A.; MacDonald, D.; Metge, D.

    1995-01-01

    Transport behaviors of unidentified flagellated protozoa (flagellates) and flagellate-sized carboxylated microspheres in sandy, organically contaminated aquifer sediments were investigated in a small-scale (1 to 4-m travel distance) natural-gradient tracer test on Cape Cod and in flow-through columns packed with sieved (0.5-to 1.0-mm grain size) aquifer sediments. The minute (average in situ cell size, 2 to 3 ??m) flagellates, which are relatively abundant in the Cape Cod aquifer, were isolated from core samples, grown in a grass extract medium, labeled with hydroethidine (a vital eukaryotic stain), and coinjected into aquifer sediments along with bromide, a conservative tracer. The 2-??m flagellates appeared to be near the optimal size for transport, judging from flowthrough column experiments involving a polydispersed (0.7 to 6.2 ??m in diameter) suspension of carboxylated microspheres. However, immobilization within the aquifer sediments accounted for a log unit reduction over the first meter of travel compared with a log unit reduction over the first 10 m of travel for indigenous, free-living groundwater bacteria in earlier tests. High rates of flagellate immobilization in the presence of aquifer sediments also was observed in the laboratory. However, immobilization rates for the laboratory-grown flagellates (initially 4 to 5 ??m) injected into the aquifer were not constant and decreased noticeably with increasing time and distance of travel. The decrease in propensity for grain surfaces was accompanied by a decrease in cell size, as the flagellates presumably readapted to aquifer conditions. Retardation and apparent dispersion were generally at least twofold greater than those observed earlier for indigenous groundwater bacteria but were much closer to those observed for highly surface active carboxylated latex microspheres. Field and laboratory results suggest that 2- ??m carboxylated microspheres may be useful as analogs in investigating several abiotic aspects of flagellate transport behavior in groundwater.

  1. Effect of island size, distance, and epicenter maturity on colonization in freshwater protozoan communities

    SciTech Connect

    Henebry, M.S.; Cairns, J. Jr.

    1980-07-01

    The purpose of this study was to: (a) obtain baseline data on the colonization of artificial islands in a closed laboratory system; (b) investigate effects of island area and distance from an epicenter (source of protozoa) on the colonization process, and (c) test the effect of the maturity of an epicenter on the colonization of surrounding islands. Islands which were smallest in area or closest to the epicenter had significantly greater species richness during the 7 days of the experiments. Islands exposed to epicenters of intermediate, maturity had significantly greater species richness than islands tested with mature (fully colonized) epicenters. Evidence gathered thus far strongly suggests that kinds of species during different periods of colonization are responsible for differences in species richness on islands exposed to epicenters of different maturities.

  2. RESPONSES OF THE PLANARIAN, DUGESIA, AND THE PROTOZOAN, PARAMECIUM, TO VERY WEAK HORIZONTAL MAGNETIC FIELDS

    Microsoft Academic Search

    FRANK A. BROWN

    The question of whether living things are sensitive to terrestrial magnetism has undoubtedly fleeted through the minds of innumerable persons since this geophysical factor first became known. But neither the naturalist, observing the behavior of organisms in the field during their continuing responses to the myriads of more obvious physical factors, nor the experimental biologist, casually testing the response of

  3. "Ormilo disease" a disorder of zebu cattle in Tanzania: bovine cerebral theileriosis or new protozoan disease?

    PubMed

    Catalano, Deborah; Biasibetti, Elena; Lynen, Godelieve; Di Giulio, Giuseppe; De Meneghi, Daniele; Tomassone, Laura; Valenza, Federico; Capucchio, Maria Teresa

    2015-06-01

    "Ormilo" disease is a neurological disorder of cattle described by Maasai herders in Tanzania. It is attributed to infection by Theileria species, although no detailed data are available in the literature. The authors describe the macroscopical and histological changes observed in 30 brains of indigenous short-horn zebu cattle from Northern Tanzania, aged 2-9 years, with the characteristic neurological signs of "Ormilo". Moreover, the ultrastructural details observed in 14 selected brain samples were reported. Areas of congestion and hemorrhages, associated with the obstruction of the cerebral vessels with large numbers of parasitized lymphoid cells, were observed. Electron microscopy showed the presence of intralymphocytic parasites morphologically comparable to flagellated protozoa, not previously described in the lymphoid cells of cattle, but only reported during the sexual stages within the vector. Theileria taurotragi was detected by polymerase chain reaction (PCR) and reverse line blot (RLB) in nine samples. The authors hypothesize that the parasite detected by electron microscopy could be a strain of a Theileria endemic to this region till now not investigated, having an intralymphocytic phase and being associated with other Theileria spp. infestation. Further studies are needed to better understand the etiology of "Ormilo" disease and to characterize the morphology of the observed parasite, clarifying its role in the disease in Tanzania. PMID:25851929

  4. Impact of Protozoan Grazing on Bacterial Community Structure in Soil Microcosms

    Microsoft Academic Search

    R. Ronn; Allison E. McCaig; Bryan S. Griffiths; James I. Prosser

    2002-01-01

    The influence of grazing by a mixed assemblage of soil protozoa (seven flagellates and one amoeba) on bacterial community structure was studied in soil microcosms amended with a particulate resource (sterile wheat roots) or a soluble resource (a solution of various organic compounds). Sterilized soil was reinoculated with mixed soil bacteria (obtained by filtering and dilution) or with bacteria and

  5. Nitazoxanide for the treatment of intestinal protozoan and helminthic infections in Mexico

    Microsoft Academic Search

    Raúl Romero Cabello; Lilía Robert Guerrero; María del Rocio Muñóz García; Alberto Geyne Cruz

    1997-01-01

    A study to evaluate the efficacy and safety of nitazoxanide as a single agent for the treatment of a broad spectrum of mixed parasitic infections, both protozoa and helminths, was conducted at a primary school in San Pedro Tolimán, Querétaro, Mexico. Three faecal samples from 1824 adults and children were screened for the presence of oocysts, cysts, trophozoites, eggs or

  6. The development of the macronucleus in the ciliated protozoan Stylonychia mytilus

    Microsoft Academic Search

    Dieter Ammermann; Günther Steinbrück; Ludwig Berger; Wolf gang Hennig

    1974-01-01

    Ciliated protozoa are characterized by generative micronuclei and vegetative polyploid macronuclei. Micronuclei of Stylonychia mytilus contain 1 600 times as much DNA per haploid genome as E. coli. Most of this DNA is shown to be repetitive. The development of the macronucleus involves, as demonstrated by cytology, only 1\\/3 of the chromosomes which in a first replication phase are polytenized

  7. Legionella pneumophila kills human phagocytes but not protozoan host cells by inducing apoptotic cell death

    Microsoft Academic Search

    Sonja Hägele; Jörg Hacker; Bettina C Brand

    1998-01-01

    Legionella pneumophila is a facultative intracellular parasite able to replicate within and to kill a variety of eukaryotic cells. One possible killing mechanism is the induction of programmed cell death. Based on electron microscopy and flow cytometry studies using the phosphatidylserine binding protein annexin V, we could demonstrate that L. pneumophila is able to induce apoptosis in human monocytes which

  8. Artemisinin Induces Calcium-Dependent Protein Secretion in the Protozoan Parasite Toxoplasma gondii? †

    PubMed Central

    Nagamune, Kisaburo; Beatty, Wandy L.; Sibley, L. David

    2007-01-01

    Intracellular calcium controls several crucial cellular events in apicomplexan parasites, including protein secretion, motility, and invasion into and egress from host cells. The plant compound thapsigargin inhibits the sarcoplasmic-endoplasmic reticulum calcium ATPase (SERCA), resulting in elevated calcium and induction of protein secretion in Toxoplasma gondii. Artemisinins are natural products that show potent and selective activity against parasites, making them useful for the treatment of malaria. While the mechanism of action is uncertain, previous studies have suggested that artemisinin may inhibit SERCA, thus disrupting calcium homeostasis. We cloned the single-copy gene encoding SERCA in T. gondii (TgSERCA) and demonstrate that the protein localizes to the endoplasmic reticulum in the parasite. In extracellular parasites, TgSERCA partially relocalized to the apical pole, a highly active site for regulated secretion of micronemes. TgSERCA complemented a calcium ATPase-defective yeast mutant, and this activity was inhibited by either thapsigargin or artemisinin. Treatment of T. gondii with artemisinin triggered calcium-dependent secretion of microneme proteins, similar to the SERCA inhibitor thapsigargin. Artemisinin treatment also altered intracellular calcium in parasites by increasing the periodicity of calcium oscillations and inducing recurrent, strong calcium spikes, as imaged using Fluo-4 labeling. Collectively, these results demonstrate that artemisinin perturbs calcium homeostasis in T. gondii, supporting the idea that Ca2+-ATPases are potential drug targets in parasites. PMID:17766463

  9. Cellular Inflammatory Response of Rainbow Trout to the Protozoan Parasite that Causes Proliferative Kidney Disease

    Microsoft Academic Search

    Elizabeth Macconnell; Charlie E. Smith; Ronald P. Hedrick; C. A. Speer

    1989-01-01

    The cellular inflammatory response of rainbow trout Oncorhynchus mykiss (formerly Salmo gairdneri) to the myxozoan parasite PKX that causes proliferative kidney disease was investigated. The response was studied from 3 to 20 weeks after the fish were injected with infected kidney homogenate. Kidney samples were examined by light and electron microscopy. In contrast to most myxosporeans, PKX provoked a severe

  10. Trans-sialidase: unique enzyme activity discovered in the protozoan Trvpanosoma cruzi

    Microsoft Academic Search

    WALTER COLLI

    Trypanosoma cruzi, the agent of Chagas' disease, an ailment characterized by a progressive chronic fibrotic myocarditis and degeneration of tissues that are innervated by the autonomic nervous system, is a vora- cious sialic acid eater from glycoconjugates of the sur- rounding medium. This is accomplished through an ac- tive trans-sialidase residing on the surface membrane of the trypomastigote stage, which

  11. Metabolic Profiling of the Protozoan Parasite Entamoeba invadens Revealed Activation of Unpredicted Pathway during Encystation

    Microsoft Academic Search

    Ghulam Jeelani; Dan Sato; Afzal Husain; Aleyla Escueta-de Cadiz; Masahiro Sugimoto; Tomoyoshi Soga; Makoto Suematsu; Tomoyoshi Nozaki

    2012-01-01

    Encystation, which is cellular differentiation from the motile, proliferative, labile trophozoite form to the dormant, resistant cyst form, is a crucial process found in parasitic and free-living protozoa such as Entamoeba, Giardia, Acanthamoeba, and Balamuthia. Since encystation is an essential process to deal with the adverse external environmental changes during the life cycle, and often integral to the transmission of

  12. Galectin-11 induction in the gastrointestinal tract of cattle following nematode and protozoan infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Galectin-11 (LGALS11) has been suggested to play an important role in protective immunity against gastrointestinal nematodes in ruminants. However, in cattle this molecule has not been characterized in detail. In the current study, it was shown that transcription of LGALS11 was highly inducible in t...

  13. Metabolic Profiling of the Protozoan Parasite Entamoeba invadens Revealed Activation of Unpredicted Pathway during Encystation

    PubMed Central

    Jeelani, Ghulam; Sato, Dan; Husain, Afzal; Escueta-de Cadiz, Aleyla; Sugimoto, Masahiro; Soga, Tomoyoshi; Suematsu, Makoto; Nozaki, Tomoyoshi

    2012-01-01

    Encystation, which is cellular differentiation from the motile, proliferative, labile trophozoite form to the dormant, resistant cyst form, is a crucial process found in parasitic and free-living protozoa such as Entamoeba, Giardia, Acanthamoeba, and Balamuthia. Since encystation is an essential process to deal with the adverse external environmental changes during the life cycle, and often integral to the transmission of the diseases, biochemical understanding of the process potentially provides useful measures against the infections caused by this group of protozoa. In this study, we investigated metabolic and transcriptomic changes that occur during encystation in Entamoeba invadens, the reptilian sibling of mammal-infecting E. histolytica, using capillary electrophoresis-tandem mass spectrometry-based metabolite profiling and DNA microarray-based expression profiling. As the encystation progressed, the levels of majority of metabolites involved in glycolysis and nucleotides drastically decreased, indicating energy generation is ceased. Furthermore, the flux of glycolysis was redirected toward chitin wall biosynthesis. We found remarkable temporal increases in biogenic amines such as isoamylamine, isobutylamine, and cadaverine, during the early period of encystation, when the trophozoites form large multicellular aggregates (precyst). We also found remarkable induction of ?-aminobutyric acid (GABA) during encystation. This study has unveiled for the first time the dynamics of the transcriptional and metabolic regulatory networks during encystation, and should help in better understanding of the process in pathogenic eukaryotes, and further development of measures controlling infections they cause. PMID:22662204

  14. MENINGOENCEPHALITIS ASSOCIATED WITH AN UNIDENTIFIED APICOMPLEXAN PROTOZOAN IN A PACIFIC HARBOR SEAL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A Pacific harbor seal (Phoca vitulina richardsii) was found on the central California coast with neurologic signs and labored breathing, which were unresponsive to treatment. Necropsy revealed a non-suppurative necrotizing meningoencephalitis, a multilocular thymic cyst, and non-suppurative cystitis...

  15. CRYPTOSPORIDIUM AND OTHER OPPORTUNISTIC PROTOZOANS POTENTIALLY TRANSMITTED FROM ANIMALS TO HUMANS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pandemic of the Human Immunodeficiecy Virus and the resultant acquired immunodeficiency disease HIV/AIDS has assumed a major, almost overwhelming, public health importance in many parts of the world. HIV steadily weakens the body's immune system, increasing susceptibility to a variety of opportu...

  16. Rates of Benthic Protozoan Grazing on Free and Attached Sediment Bacteria Measured with Fluorescently Stained Sediment

    PubMed Central

    Starink, Mathieu; Krylova, Irina N.; Bär-Gilissen, Marie-José; Bak, Rolf P. M.; Cappenberg, Thomas E.

    1994-01-01

    In order to determine the importance of benthic protozoa as consumers of bacteria, grazing rates have been measured by using monodispersed fluorescently labeled bacteria (FLB). However, high percentages of nongrazing benthic protists are reported in the literature. These are related to serious problems of the monodispersed FLB method. We describe a new method using 5-(4,6-dichlorotriazin-2-yl)-aminofluorescein (DTAF)-stained sediment to measure in situ bacterivory by benthic protists. This method is compared with the monodispersed FLB technique. Our estimates of benthic bacterivory range from 61 to 73 bacteria protist-1 h-1 and are about twofold higher than the results of the monodispersed FLB method. The number of nongrazing protists after incubation for 15 min with DTAF-stained sediment is in agreement with theoretical expectation. We also tested the relative affinity for FLB of protists and discuss the results with respect to a grazing model. PMID:16349315

  17. Protozoan Parasite Growth Inhibitors Discovered by Cross-Screening Yield Potent Scaffolds for Lead Discovery.

    PubMed

    Devine, William; Woodring, Jennifer L; Swaminathan, Uma; Amata, Emanuele; Patel, Gautam; Erath, Jessey; Roncal, Norma E; Lee, Patricia J; Leed, Susan E; Rodriguez, Ana; Mensa-Wilmot, Kojo; Sciotti, Richard J; Pollastri, Michael P

    2015-07-23

    Tropical protozoal infections are a significant cause of morbidity and mortality worldwide; four in particular (human African trypanosomiasis (HAT), Chagas disease, cutaneous leishmaniasis, and malaria) have an estimated combined burden of over 87 million disability-adjusted life years. New drugs are needed for each of these diseases. Building on the previous identification of NEU-617 (1) as a potent and nontoxic inhibitor of proliferation for the HAT pathogen (Trypanosoma brucei), we have now tested this class of analogs against other protozoal species: T. cruzi (Chagas disease), Leishmania major (cutaneous leishmaniasis), and Plasmodium falciparum (malaria). Based on hits identified in this screening campaign, we describe the preparation of several replacements for the quinazoline scaffold and report these inhibitors' biological activities against these parasites. In doing this, we have identified several potent proliferation inhibitors for each pathogen, such as 4-((3-chloro-4-((3-fluorobenzyl)oxy)phenyl)amino)-6-(4-((4-methyl-1,4-diazepan-1-yl)sulfonyl)phenyl)quinoline-3-carbonitrile (NEU-924, 83) for T. cruzi and N-(3-chloro-4-((3-fluorobenzyl)oxy)phenyl)-7-(4-((4-methyl-1,4-diazepan-1-yl)sulfonyl)phenyl)cinnolin-4-amine (NEU-1017, 68) for L. major and P. falciparum. PMID:26087257

  18. Trophic upgrading of food quality by protozoans enhancing copepod growth: role of essential lipids

    Microsoft Academic Search

    W. C. M. Klein Breteler; N. Schogt; M. Baas; S. Schouten; G. W. Kraay

    1999-01-01

    Protozoa are known for their intermediary trophic role in transferring organic matter from small size planktonic particles\\u000a to mesozooplankton. This study concentrates on the possible addition of biochemical value during this transfer, by new production\\u000a of compounds that are essential in copepod food. In laboratory experiments, copepods could not be raised on a diet of the\\u000a chlorophycean Dunaliella sp., though

  19. CONCERNS RELATED TO PROTOZOAN AND HELMINTH PARASITES IN BIOSOLIDS AND ANIMAL WASTES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This in-depth review of parasites found in municipal wastewater effluents, biosolids, or animal wastes and considered to be a concern to public health includes the protozoa Cryptosporidium, Cyclospora, Toxoplasma, Microsporidia, Balantidium, Giardia, and Entamoeba as well as the helminths Trichuris,...

  20. EFFECT OF GROWTH RATE AND HYDROPHOBICITY ON BACTERIA SURVIVING PROTOZOAN GRAZING

    EPA Science Inventory

    Measurements were made of the predation by Tetrahymena thermophila on several bacterial species in media containing heat-killed Escherichia cells to serve as an alternative prey. f grazing pressure was initially not intense on a mixture of bacterial species, the species that surv...